binutils-gdb/include/ctf-api.h

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/* Public API to libctf.
Copyright (C) 2019-2020 Free Software Foundation, Inc.
This file is part of libctf.
libctf is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not see
<http://www.gnu.org/licenses/>. */
/* This header file defines the interfaces available from the CTF debugger
library, libctf. This API can be used by a debugger to operate on data in
the Compact ANSI-C Type Format (CTF). */
#ifndef _CTF_API_H
#define _CTF_API_H
#include <sys/types.h>
#include <ctf.h>
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
2019-04-24 05:45:46 +08:00
#include <zlib.h>
#ifdef __cplusplus
extern "C"
{
#endif
/* Clients can open one or more CTF containers and obtain a pointer to an
opaque ctf_file_t. Types are identified by an opaque ctf_id_t token.
They can also open or create read-only archives of CTF containers in a
ctf_archive_t.
These opaque definitions allow libctf to evolve without breaking clients. */
typedef struct ctf_file ctf_file_t;
typedef struct ctf_archive_internal ctf_archive_t;
libctf: fix a number of build problems found on Solaris and NetBSD - Use of nonportable <endian.h> - Use of qsort_r - Use of zlib without appropriate magic to pull in the binutils zlib - Use of off64_t without checking (fixed by dropping the unused fields that need off64_t entirely) - signedness problems due to long being too short a type on 32-bit platforms: ctf_id_t is now 'unsigned long', and CTF_ERR must be used only for functions that return ctf_id_t - One lingering use of bzero() and of <sys/errno.h> All fixed, using code from gnulib where possible. Relatedly, set cts_size in a couple of places it was missed (string table and symbol table loading upon ctf_bfdopen()). binutils/ * objdump.c (make_ctfsect): Drop cts_type, cts_flags, and cts_offset. * readelf.c (shdr_to_ctf_sect): Likewise. include/ * ctf-api.h (ctf_sect_t): Drop cts_type, cts_flags, and cts_offset. (ctf_id_t): This is now an unsigned type. (CTF_ERR): Cast it to ctf_id_t. Note that it should only be used for ctf_id_t-returning functions. libctf/ * Makefile.am (ZLIB): New. (ZLIBINC): Likewise. (AM_CFLAGS): Use them. (libctf_a_LIBADD): New, for LIBOBJS. * configure.ac: Check for zlib, endian.h, and qsort_r. * ctf-endian.h: New, providing htole64 and le64toh. * swap.h: Code style fixes. (bswap_identity_64): New. * qsort_r.c: New, from gnulib (with one added #include). * ctf-decls.h: New, providing a conditional qsort_r declaration, and unconditional definitions of MIN and MAX. * ctf-impl.h: Use it. Do not use <sys/errno.h>. (ctf_set_errno): Now returns unsigned long. * ctf-util.c (ctf_set_errno): Adjust here too. * ctf-archive.c: Use ctf-endian.h. (ctf_arc_open_by_offset): Use memset, not bzero. Drop cts_type, cts_flags and cts_offset. (ctf_arc_write): Drop debugging dependent on the size of off_t. * ctf-create.c: Provide a definition of roundup if not defined. (ctf_create): Drop cts_type, cts_flags and cts_offset. (ctf_add_reftype): Do not check if type IDs are below zero. (ctf_add_slice): Likewise. (ctf_add_typedef): Likewise. (ctf_add_member_offset): Cast error-returning ssize_t's to size_t when known error-free. Drop CTF_ERR usage for functions returning int. (ctf_add_member_encoded): Drop CTF_ERR usage for functions returning int. (ctf_add_variable): Likewise. (enumcmp): Likewise. (enumadd): Likewise. (membcmp): Likewise. (ctf_add_type): Likewise. Cast error-returning ssize_t's to size_t when known error-free. * ctf-dump.c (ctf_is_slice): Drop CTF_ERR usage for functions returning int: use CTF_ERR for functions returning ctf_type_id. (ctf_dump_label): Likewise. (ctf_dump_objts): Likewise. * ctf-labels.c (ctf_label_topmost): Likewise. (ctf_label_iter): Likewise. (ctf_label_info): Likewise. * ctf-lookup.c (ctf_func_args): Likewise. * ctf-open.c (upgrade_types): Cast to size_t where appropriate. (ctf_bufopen): Likewise. Use zlib types as needed. * ctf-types.c (ctf_member_iter): Drop CTF_ERR usage for functions returning int. (ctf_enum_iter): Likewise. (ctf_type_size): Likewise. (ctf_type_align): Likewise. Cast to size_t where appropriate. (ctf_type_kind_unsliced): Likewise. (ctf_type_kind): Likewise. (ctf_type_encoding): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_value): Likewise. (ctf_type_rvisit): Likewise. * ctf-open-bfd.c (ctf_bfdopen): Drop cts_type, cts_flags and cts_offset. (ctf_simple_open): Likewise. (ctf_bfdopen_ctfsect): Likewise. Set cts_size properly. * Makefile.in: Regenerate. * aclocal.m4: Likewise. * config.h: Likewise. * configure: Likewise.
2019-05-31 17:10:51 +08:00
typedef unsigned long ctf_id_t;
/* This opaque definition allows libctf to accept BFD data structures without
importing all the BFD noise into users' namespaces. */
struct bfd;
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
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/* If the debugger needs to provide the CTF library with a set of raw buffers
for use as the CTF data, symbol table, and string table, it can do so by
filling in ctf_sect_t structures and passing them to ctf_bufopen().
The contents of this structure must always be in native endianness (no
byteswapping is performed). */
typedef struct ctf_sect
{
const char *cts_name; /* Section name (if any). */
const void *cts_data; /* Pointer to section data. */
size_t cts_size; /* Size of data in bytes. */
size_t cts_entsize; /* Size of each section entry (symtab only). */
} ctf_sect_t;
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
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/* A minimal symbol extracted from a linker's internal symbol table
representation. */
typedef struct ctf_link_sym
{
/* The st_name will not be accessed outside the call to
ctf_link_shuffle_syms(). */
const char *st_name;
uint32_t st_shndx;
uint32_t st_type;
uint32_t st_value;
} ctf_link_sym_t;
libctf, link: redo cu-mapping handling Now a bunch of stuff that doesn't apply to ld or any normal use of libctf, piled into one commit so that it's easier to ignore. The cu-mapping machinery associates incoming compilation unit names with outgoing names of CTF dictionaries that should correspond to them, for non-gdb CTF consumers that would like to group multiple TUs into a single child dict if conflicting types are found in it (the existing use case is one kernel module, one child CTF dict, even if the kernel module is composed of multiple CUs). The upcoming deduplicator needs to track not only the mapping from incoming CU name to outgoing dict name, but the inverse mapping from outgoing dict name to incoming CU name, so it can work over every CTF dict we might see in the output and link into it. So rejig the ctf-link machinery to do that. Simultaneously (because they are closely associated and were written at the same time), we add a new CTF_LINK_EMPTY_CU_MAPPINGS flag to ctf_link, which tells the ctf_link machinery to create empty child dicts for each outgoing CU mapping even if no CUs that correspond to it exist in the link. This is a bit (OK, quite a lot) of a waste of space, but some existing consumers require it. (Nobody else should use it.) Its value is not consecutive with existing CTF_LINK flag values because we're about to add more flags that are conceptually closer to the existing ones than this one is. include/ * ctf-api.h (CTF_LINK_EMPTY_CU_MAPPINGS): New. libctf/ * ctf-impl.h (ctf_file_t): Improve comments. <ctf_link_cu_mapping>: Split into... <ctf_link_in_cu_mapping>: ... this... <ctf_link_out_cu_mapping>: ... and this. * ctf-create.c (ctf_serialize): Adjust. * ctf-open.c (ctf_file_close): Likewise. * ctf-link.c (ctf_create_per_cu): Look things up in the in_cu_mapping instead of the cu_mapping. (ctf_link_add_cu_mapping): The deduplicating link will define what happens if many FROMs share a TO. (ctf_link_add_cu_mapping): Create in_cu_mapping and out_cu_mapping. Do not create ctf_link_outputs here any more, or create per-CU dicts here: they are already created when needed. (ctf_link_one_variable): Log a debug message if we skip a variable due to its type being concealed in a CU-mapped link. (This is probably too common a case to make into a warning.) (ctf_link): Create empty per-CU dicts if requested.
2020-06-06 00:36:16 +08:00
/* Flags applying to this specific link. */
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
2019-07-14 04:06:55 +08:00
/* Share all types that are not in conflict. The default. */
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
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#define CTF_LINK_SHARE_UNCONFLICTED 0x0
/* Share only types that are used by multiple inputs. */
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
2019-07-14 04:06:55 +08:00
#define CTF_LINK_SHARE_DUPLICATED 0x1
libctf, link: tie in the deduplicating linker This fairly intricate commit connects up the CTF linker machinery (which operates in terms of ctf_archive_t's on ctf_link_inputs -> ctf_link_outputs) to the deduplicator (which operates in terms of arrays of ctf_file_t's, all the archives exploded). The nondeduplicating linker is retained, but is not called unless the CTF_LINK_NONDEDUP flag is passed in (which ld never does), or the environment variable LD_NO_CTF_DEDUP is set. Eventually, once we have confidence in the much-more-complex deduplicating linker, I hope the nondeduplicating linker can be removed. In brief, what this does is traverses each input archive in ctf_link_inputs, opening every member (if not already open) and tying child dicts to their parents, shoving them into an array and constructing a corresponding parents array that tells the deduplicator which dict is the parent of which child. We then call ctf_dedup and ctf_dedup_emit with that array of inputs, taking the outputs that result and putting them into ctf_link_outputs where the rest of the CTF linker expects to find them, then linking in the variables just as is done by the nondeduplicating linker. It also implements much of the CU-mapping side of things. The problem CU-mapping introduces is that if you map many input CUs into one output, this is saying that you want many translation units to produce at most one child dict if conflicting types are found in any of them. This means you can suddenly have multiple distinct types with the same name in the same dict, which libctf cannot really represent because it's not something you can do with C translation units. The deduplicator machinery already committed does as best it can with these, hiding types with conflicting names rather than making child dicts out of them: but we still need to call it. This is done similarly to the main link, taking the inputs (one CU output at a time), deduplicating them, taking the output and making it an input to the final link. Two (significant) optimizations are done: we share atoms tables between all these links and the final link (so e.g. all type hash values are shared, all decorated type names, etc); and any CU-mapped links with only one input (and no child dicts) doesn't need to do anything other than renaming the CU: the CU-mapped link phase can be skipped for it. Put together, large CU-mapped links can save 50% of their memory usage and about as much time (and the memory usage for CU-mapped links is significant, because all those output CUs have to have all their types stored in memory all at once). include/ * ctf-api.h (CTF_LINK_NONDEDUP): New, turn off the deduplicator. libctf/ * ctf-impl.h (ctf_list_splice): New. * ctf-util.h (ctf_list_splice): Likewise. * ctf-link.c (link_sort_inputs_cb_arg_t): Likewise. (ctf_link_sort_inputs): Likewise. (ctf_link_deduplicating_count_inputs): Likewise. (ctf_link_deduplicating_open_inputs): Likewise. (ctf_link_deduplicating_close_inputs): Likewise. (ctf_link_deduplicating_variables): Likewise. (ctf_link_deduplicating_per_cu): Likewise. (ctf_link_deduplicating): Likewise. (ctf_link): Call it.
2020-06-06 05:57:06 +08:00
/* Do a nondeduplicating link. */
#define CTF_LINK_NONDEDUP 0x2
libctf, link: redo cu-mapping handling Now a bunch of stuff that doesn't apply to ld or any normal use of libctf, piled into one commit so that it's easier to ignore. The cu-mapping machinery associates incoming compilation unit names with outgoing names of CTF dictionaries that should correspond to them, for non-gdb CTF consumers that would like to group multiple TUs into a single child dict if conflicting types are found in it (the existing use case is one kernel module, one child CTF dict, even if the kernel module is composed of multiple CUs). The upcoming deduplicator needs to track not only the mapping from incoming CU name to outgoing dict name, but the inverse mapping from outgoing dict name to incoming CU name, so it can work over every CTF dict we might see in the output and link into it. So rejig the ctf-link machinery to do that. Simultaneously (because they are closely associated and were written at the same time), we add a new CTF_LINK_EMPTY_CU_MAPPINGS flag to ctf_link, which tells the ctf_link machinery to create empty child dicts for each outgoing CU mapping even if no CUs that correspond to it exist in the link. This is a bit (OK, quite a lot) of a waste of space, but some existing consumers require it. (Nobody else should use it.) Its value is not consecutive with existing CTF_LINK flag values because we're about to add more flags that are conceptually closer to the existing ones than this one is. include/ * ctf-api.h (CTF_LINK_EMPTY_CU_MAPPINGS): New. libctf/ * ctf-impl.h (ctf_file_t): Improve comments. <ctf_link_cu_mapping>: Split into... <ctf_link_in_cu_mapping>: ... this... <ctf_link_out_cu_mapping>: ... and this. * ctf-create.c (ctf_serialize): Adjust. * ctf-open.c (ctf_file_close): Likewise. * ctf-link.c (ctf_create_per_cu): Look things up in the in_cu_mapping instead of the cu_mapping. (ctf_link_add_cu_mapping): The deduplicating link will define what happens if many FROMs share a TO. (ctf_link_add_cu_mapping): Create in_cu_mapping and out_cu_mapping. Do not create ctf_link_outputs here any more, or create per-CU dicts here: they are already created when needed. (ctf_link_one_variable): Log a debug message if we skip a variable due to its type being concealed in a CU-mapped link. (This is probably too common a case to make into a warning.) (ctf_link): Create empty per-CU dicts if requested.
2020-06-06 00:36:16 +08:00
/* Create empty outputs for all registered CU mappings even if no types are
emitted into them. */
#define CTF_LINK_EMPTY_CU_MAPPINGS 0x4
/* Omit the content of the variables section. */
#define CTF_LINK_OMIT_VARIABLES_SECTION 0x8
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
2019-04-24 05:45:46 +08:00
/* Symbolic names for CTF sections. */
typedef enum ctf_sect_names
{
CTF_SECT_HEADER,
CTF_SECT_LABEL,
CTF_SECT_OBJT,
CTF_SECT_FUNC,
CTF_SECT_VAR,
CTF_SECT_TYPE,
CTF_SECT_STR
} ctf_sect_names_t;
/* Encoding information for integers, floating-point values, and certain other
intrinsics can be obtained by calling ctf_type_encoding(), below. The flags
field will contain values appropriate for the type defined in <ctf.h>. */
typedef struct ctf_encoding
{
uint32_t cte_format; /* Data format (CTF_INT_* or CTF_FP_* flags). */
uint32_t cte_offset; /* Offset of value in bits. */
uint32_t cte_bits; /* Size of storage in bits. */
} ctf_encoding_t;
typedef struct ctf_membinfo
{
ctf_id_t ctm_type; /* Type of struct or union member. */
unsigned long ctm_offset; /* Offset of member in bits. */
} ctf_membinfo_t;
typedef struct ctf_arinfo
{
ctf_id_t ctr_contents; /* Type of array contents. */
ctf_id_t ctr_index; /* Type of array index. */
uint32_t ctr_nelems; /* Number of elements. */
} ctf_arinfo_t;
typedef struct ctf_funcinfo
{
ctf_id_t ctc_return; /* Function return type. */
uint32_t ctc_argc; /* Number of typed arguments to function. */
uint32_t ctc_flags; /* Function attributes (see below). */
} ctf_funcinfo_t;
typedef struct ctf_lblinfo
{
ctf_id_t ctb_type; /* Last type associated with the label. */
} ctf_lblinfo_t;
typedef struct ctf_snapshot_id
{
unsigned long dtd_id; /* Highest DTD ID at time of snapshot. */
unsigned long snapshot_id; /* Snapshot id at time of snapshot. */
} ctf_snapshot_id_t;
#define CTF_FUNC_VARARG 0x1 /* Function arguments end with varargs. */
libctf: fix a number of build problems found on Solaris and NetBSD - Use of nonportable <endian.h> - Use of qsort_r - Use of zlib without appropriate magic to pull in the binutils zlib - Use of off64_t without checking (fixed by dropping the unused fields that need off64_t entirely) - signedness problems due to long being too short a type on 32-bit platforms: ctf_id_t is now 'unsigned long', and CTF_ERR must be used only for functions that return ctf_id_t - One lingering use of bzero() and of <sys/errno.h> All fixed, using code from gnulib where possible. Relatedly, set cts_size in a couple of places it was missed (string table and symbol table loading upon ctf_bfdopen()). binutils/ * objdump.c (make_ctfsect): Drop cts_type, cts_flags, and cts_offset. * readelf.c (shdr_to_ctf_sect): Likewise. include/ * ctf-api.h (ctf_sect_t): Drop cts_type, cts_flags, and cts_offset. (ctf_id_t): This is now an unsigned type. (CTF_ERR): Cast it to ctf_id_t. Note that it should only be used for ctf_id_t-returning functions. libctf/ * Makefile.am (ZLIB): New. (ZLIBINC): Likewise. (AM_CFLAGS): Use them. (libctf_a_LIBADD): New, for LIBOBJS. * configure.ac: Check for zlib, endian.h, and qsort_r. * ctf-endian.h: New, providing htole64 and le64toh. * swap.h: Code style fixes. (bswap_identity_64): New. * qsort_r.c: New, from gnulib (with one added #include). * ctf-decls.h: New, providing a conditional qsort_r declaration, and unconditional definitions of MIN and MAX. * ctf-impl.h: Use it. Do not use <sys/errno.h>. (ctf_set_errno): Now returns unsigned long. * ctf-util.c (ctf_set_errno): Adjust here too. * ctf-archive.c: Use ctf-endian.h. (ctf_arc_open_by_offset): Use memset, not bzero. Drop cts_type, cts_flags and cts_offset. (ctf_arc_write): Drop debugging dependent on the size of off_t. * ctf-create.c: Provide a definition of roundup if not defined. (ctf_create): Drop cts_type, cts_flags and cts_offset. (ctf_add_reftype): Do not check if type IDs are below zero. (ctf_add_slice): Likewise. (ctf_add_typedef): Likewise. (ctf_add_member_offset): Cast error-returning ssize_t's to size_t when known error-free. Drop CTF_ERR usage for functions returning int. (ctf_add_member_encoded): Drop CTF_ERR usage for functions returning int. (ctf_add_variable): Likewise. (enumcmp): Likewise. (enumadd): Likewise. (membcmp): Likewise. (ctf_add_type): Likewise. Cast error-returning ssize_t's to size_t when known error-free. * ctf-dump.c (ctf_is_slice): Drop CTF_ERR usage for functions returning int: use CTF_ERR for functions returning ctf_type_id. (ctf_dump_label): Likewise. (ctf_dump_objts): Likewise. * ctf-labels.c (ctf_label_topmost): Likewise. (ctf_label_iter): Likewise. (ctf_label_info): Likewise. * ctf-lookup.c (ctf_func_args): Likewise. * ctf-open.c (upgrade_types): Cast to size_t where appropriate. (ctf_bufopen): Likewise. Use zlib types as needed. * ctf-types.c (ctf_member_iter): Drop CTF_ERR usage for functions returning int. (ctf_enum_iter): Likewise. (ctf_type_size): Likewise. (ctf_type_align): Likewise. Cast to size_t where appropriate. (ctf_type_kind_unsliced): Likewise. (ctf_type_kind): Likewise. (ctf_type_encoding): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_value): Likewise. (ctf_type_rvisit): Likewise. * ctf-open-bfd.c (ctf_bfdopen): Drop cts_type, cts_flags and cts_offset. (ctf_simple_open): Likewise. (ctf_bfdopen_ctfsect): Likewise. Set cts_size properly. * Makefile.in: Regenerate. * aclocal.m4: Likewise. * config.h: Likewise. * configure: Likewise.
2019-05-31 17:10:51 +08:00
/* Functions that return a ctf_id_t use the following value to indicate failure.
ctf_errno() can be used to obtain an error code. Functions that return
a straight integral -1 also use ctf_errno(). */
#define CTF_ERR ((ctf_id_t) -1L)
#define ECTF_BASE 1000 /* Base value for libctf errnos. */
enum
{
libctf: restructure error handling to reduce relocations Jose Marchesi noted that the traditional-Unix error array in ctf-error.c introduces one reloc per error to initialize the array: 58 so far. We can reduce this to zero using an array of carefully-sized individual members which is used to construct a string table, that is then referenced by the lookup functions: but doing this automatically is a pain. Bruno Haible wrote suitable code years ago: I got permission to reuse it (Bruno says "... which I hereby put in the public domain"); I modified it a tiny bit (similarly to what Ulrich Drepper did in the dsohowto text, but I redid it from scratch), commented it up a bit, and shifted the error table into that form, migrating it into the new file ctf-error.h. This has the advantage that it spotted both typos in the text of the errors in the comments in ctf-api.h and typos in the error defines in the comments in ctf-error.c, and places where the two were simply not in sync. All are now fixed. One new constant exists in ctf-api.h: CTF_NERR, since the old method of working out the number of errors in ctf-error.c was no longer usable, and it seems that the number of CTF errors is something users might reasonably want as well. It should be pretty easy to keep up to date as new errors are introduced. include/ * ctf-api.h (ECTF_*): Improve comments. (ECTF_NERR): New. libctf/ * ctf-error.c: Include <stddef.h>, for offsetof. (_ctf_errlist): Migrate to... (_ctf_errlist_t): ... this. (_ctf_erridx): New, indexes into _ctf_errlist_t. (_ctf_nerr): Remove. (ctf_errmsg): Adjust accordingly. * Makefile.am (BUILT_SOURCES): Note... (ctf-error.h): ... this new rule. * Makefile.in: Regenerate. * mkerrors.sed: New, process ctf-api.h to generate ctf-error.h. * .gitignore: New, ignore ctf-error.h.
2020-06-03 02:07:08 +08:00
ECTF_FMT = ECTF_BASE, /* File is not in CTF or ELF format. */
ECTF_BFDERR, /* BFD error. */
ECTF_CTFVERS, /* CTF dict version is too new for libctf. */
ECTF_BFD_AMBIGUOUS, /* Ambiguous BFD target. */
ECTF_SYMTAB, /* Symbol table uses invalid entry size. */
ECTF_SYMBAD, /* Symbol table data buffer is not valid. */
ECTF_STRBAD, /* String table data buffer is not valid. */
ECTF_CORRUPT, /* File data structure corruption detected. */
ECTF_NOCTFDATA, /* File does not contain CTF data. */
ECTF_NOCTFBUF, /* Buffer does not contain CTF data. */
ECTF_NOSYMTAB, /* Symbol table information is not available. */
ECTF_NOPARENT, /* The parent CTF dictionary is unavailable. */
ECTF_DMODEL, /* Data model mismatch. */
ECTF_LINKADDEDLATE, /* File added to link too late. */
ECTF_ZALLOC, /* Failed to allocate (de)compression buffer. */
ECTF_DECOMPRESS, /* Failed to decompress CTF data. */
ECTF_STRTAB, /* External string table is not available. */
ECTF_BADNAME, /* String name offset is corrupt. */
ECTF_BADID, /* Invalid type identifier. */
ECTF_NOTSOU, /* Type is not a struct or union. */
ECTF_NOTENUM, /* Type is not an enum. */
ECTF_NOTSUE, /* Type is not a struct, union, or enum. */
ECTF_NOTINTFP, /* Type is not an integer, float, or enum. */
ECTF_NOTARRAY, /* Type is not an array. */
ECTF_NOTREF, /* Type does not reference another type. */
ECTF_NAMELEN, /* Buffer is too small to hold type name. */
ECTF_NOTYPE, /* No type found corresponding to name. */
ECTF_SYNTAX, /* Syntax error in type name. */
ECTF_NOTFUNC, /* Symbol table entry or type is not a function. */
ECTF_NOFUNCDAT, /* No function information available for function. */
ECTF_NOTDATA, /* Symbol table entry does not refer to a data object. */
ECTF_NOTYPEDAT, /* No type information available for symbol. */
ECTF_NOLABEL, /* No label found corresponding to name. */
ECTF_NOLABELDATA, /* File does not contain any labels. */
ECTF_NOTSUP, /* Feature not supported. */
ECTF_NOENUMNAM, /* Enum element name not found. */
ECTF_NOMEMBNAM, /* Member name not found. */
ECTF_RDONLY, /* CTF container is read-only. */
ECTF_DTFULL, /* CTF type is full (no more members allowed). */
ECTF_FULL, /* CTF container is full. */
ECTF_DUPLICATE, /* Duplicate member or variable name. */
ECTF_CONFLICT, /* Conflicting type is already defined. */
ECTF_OVERROLLBACK, /* Attempt to roll back past a ctf_update. */
ECTF_COMPRESS, /* Failed to compress CTF data. */
ECTF_ARCREATE, /* Error creating CTF archive. */
ECTF_ARNNAME, /* Name not found in CTF archive. */
ECTF_SLICEOVERFLOW, /* Overflow of type bitness or offset in slice. */
ECTF_DUMPSECTUNKNOWN, /* Unknown section number in dump. */
ECTF_DUMPSECTCHANGED, /* Section changed in middle of dump. */
ECTF_NOTYET, /* Feature not yet implemented. */
libctf, ld, binutils: add textual error/warning reporting for libctf This commit adds a long-missing piece of infrastructure to libctf: the ability to report errors and warnings using all the power of printf, rather than being restricted to one errno value. Internally, libctf calls ctf_err_warn() to add errors and warnings to a list: a new iterator ctf_errwarning_next() then consumes this list one by one and hands it to the caller, which can free it. New errors and warnings are added until the list is consumed by the caller or the ctf_file_t is closed, so you can dump them at intervals. The caller can of course choose to print only those warnings it wants. (I am not sure whether we want objdump, readelf or ld to print warnings or not: right now I'm printing them, but maybe we only want to print errors? This entirely depends on whether warnings are voluminous things describing e.g. the inability to emit single types because of name clashes or something. There are no users of this infrastructure yet, so it's hard to say.) There is no internationalization here yet, but this at least adds a place where internationalization can be added, to one of ctf_errwarning_next or ctf_err_warn. We also provide a new ctf_assert() function which uses this infrastructure to provide non-fatal assertion failures while emitting an assert-like string to the caller: to save space and avoid needlessly duplicating unchanging strings, the assertion test is inlined but the print-things-out failure case is not. All assertions in libctf will be converted to use this machinery in future commits and propagate assertion-failure errors up, so that the linker in particular cannot be killed by libctf assertion failures when it could perfectly well just print warnings and drop the CTF section. include/ * ctf-api.h (ECTF_INTERNAL): Adjust error text. (ctf_errwarning_next): New. libctf/ * ctf-impl.h (ctf_assert): New. (ctf_err_warning_t): Likewise. (ctf_file_t) <ctf_errs_warnings>: Likewise. (ctf_err_warn): New prototype. (ctf_assert_fail_internal): Likewise. * ctf-inlines.h (ctf_assert_internal): Likewise. * ctf-open.c (ctf_file_close): Free ctf_errs_warnings. * ctf-create.c (ctf_serialize): Copy it on serialization. * ctf-subr.c (ctf_err_warn): New, add an error/warning. (ctf_errwarning_next): New iterator, free and pass back errors/warnings in succession. * libctf.ver (ctf_errwarning_next): Add. ld/ * ldlang.c (lang_ctf_errs_warnings): New, print CTF errors and warnings. Assert when libctf asserts. (lang_merge_ctf): Call it. (land_write_ctf): Likewise. binutils/ * objdump.c (ctf_archive_member): Print CTF errors and warnings. * readelf.c (dump_ctf_archive_member): Likewise.
2020-06-04 22:07:54 +08:00
ECTF_INTERNAL, /* Internal error: assertion failure. */
libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf_*_iter functions that take a callback and an arg and repeatedly call it. This *works*, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The *_next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t *i = NULL; int *hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t *i = NULL; ssize_t offset; const char *name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { /* do something with offset, name, and membtype */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf_*_next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. */ ssize_t ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, const char **name, ctf_id_t *membtype); /* Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. */ const char * ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, int *val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. */ ctf_file_t * ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name, int skip_parent, int *errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.
2020-06-03 22:13:24 +08:00
ECTF_NONREPRESENTABLE, /* Type not representable in CTF. */
ECTF_NEXT_END, /* End of iteration. */
ECTF_NEXT_WRONGFUN, /* Wrong iteration function called. */
ECTF_NEXT_WRONGFP, /* Iteration entity changed in mid-iterate. */
libctf, link: add lazy linking: clean up input members: err/warn cleanup This rather large and intertwined pile of changes does three things: First, it transitions from dprintf to ctf_err_warn for things the user might care about: this one file is the major impetus for the ctf_err_warn infrastructure, because things like file names are crucial in linker error messages, and errno values are utterly incapable of communicating them Second, it stabilizes the ctf_link APIs: you can now call ctf_link_add_ctf without a CTF argument (only a NAME), to lazily ctf_open the file with the given NAME when needed, and close it as soon as possible, to save memory. This is not an API change because a null CTF argument was prohibited before now. Since getting CTF directly from files uses ctf_open, passing in only a NAME requires use of libctf, not libctf-nobfd. The linker's behaviour is unchanged, as it still passes in a ctf_archive_t as before. This also let us fix a leak: we were opening ctf_archives and their containing ctf_files, then only closing the files and leaving the archives open. Third, this commit restructures the ctf_link_in_member argument used by the CTF linking machinery and adjusts its users accordingly. We drop two members: - arcname, which is difficult to construct and then only used in error messages (that were only dprintf()ed, so never seen!) - share_mode, since we store the flags passed to ctf_link (including the share mode) in a new ctf_file_t.ctf_link_flags to help dedup get hold of it We rename others whose existing names were fairly dreadful: - done_main_member -> done_parent, using consistent terminology for .ctf as the parent of all archive members - main_input_fp -> in_fp_parent, likewise - file_name -> in_file_name, likewise We add one new member, cu_mapped. Finally, we move the various frees of things like mapping table data to the top-level ctf_link, since deduplicating links will want to do that too. include/ * ctf-api.h (ECTF_NEEDSBFD): New. (ECTF_NERR): Adjust. (ctf_link): Rename share_mode arg to flags. libctf/ * Makefile.am: Set -DNOBFD=1 in libctf-nobfd, and =0 elsewhere. * Makefile.in: Regenerated. * ctf-impl.h (ctf_link_input_name): New. (ctf_file_t) <ctf_link_flags>: New. * ctf-create.c (ctf_serialize): Adjust accordingly. * ctf-link.c: Define ctf_open as weak when PIC. (ctf_arc_close_thunk): Remove unnecessary thunk. (ctf_file_close_thunk): Likewise. (ctf_link_input_name): New. (ctf_link_input_t): New value of the ctf_file_t.ctf_link_input. (ctf_link_input_close): Adjust accordingly. (ctf_link_add_ctf_internal): New, split from... (ctf_link_add_ctf): ... here. Return error if lazy loading of CTF is not possible. Change to just call... (ctf_link_add): ... this new function. (ctf_link_add_cu_mapping): Transition to ctf_err_warn. Drop the ctf_file_close_thunk. (ctf_link_in_member_cb_arg_t) <file_name> Rename to... <in_file_name>: ... this. <arcname>: Drop. <share_mode>: Likewise (migrated to ctf_link_flags). <done_main_member>: Rename to... <done_parent>: ... this. <main_input_fp>: Rename to... <in_fp_parent>: ... this. <cu_mapped>: New. (ctf_link_one_type): Adjuwt accordingly. Transition to ctf_err_warn, removing a TODO. (ctf_link_one_variable): Note a case too common to warn about. Report in the debug stream if a cu-mapped link prevents addition of a conflicting variable. (ctf_link_one_input_archive_member): Adjust. (ctf_link_lazy_open): New, open a CTF archive for linking when needed. (ctf_link_close_one_input_archive): New, close it again. (ctf_link_one_input_archive): Adjust for lazy opening, member renames, and ctf_err_warn transition. Move the empty_link_type_mapping call to... (ctf_link): ... here. Adjut for renamings and thunk removal. Don't spuriously fail if some input contains no CTF data. (ctf_link_write): ctf_err_warn transition. * libctf.ver: Remove not-yet-stable comment.
2020-06-05 02:28:52 +08:00
ECTF_FLAGS, /* CTF header contains flags unknown to libctf. */
ECTF_NEEDSBFD /* This feature needs a libctf with BFD support. */
};
libctf, link: add lazy linking: clean up input members: err/warn cleanup This rather large and intertwined pile of changes does three things: First, it transitions from dprintf to ctf_err_warn for things the user might care about: this one file is the major impetus for the ctf_err_warn infrastructure, because things like file names are crucial in linker error messages, and errno values are utterly incapable of communicating them Second, it stabilizes the ctf_link APIs: you can now call ctf_link_add_ctf without a CTF argument (only a NAME), to lazily ctf_open the file with the given NAME when needed, and close it as soon as possible, to save memory. This is not an API change because a null CTF argument was prohibited before now. Since getting CTF directly from files uses ctf_open, passing in only a NAME requires use of libctf, not libctf-nobfd. The linker's behaviour is unchanged, as it still passes in a ctf_archive_t as before. This also let us fix a leak: we were opening ctf_archives and their containing ctf_files, then only closing the files and leaving the archives open. Third, this commit restructures the ctf_link_in_member argument used by the CTF linking machinery and adjusts its users accordingly. We drop two members: - arcname, which is difficult to construct and then only used in error messages (that were only dprintf()ed, so never seen!) - share_mode, since we store the flags passed to ctf_link (including the share mode) in a new ctf_file_t.ctf_link_flags to help dedup get hold of it We rename others whose existing names were fairly dreadful: - done_main_member -> done_parent, using consistent terminology for .ctf as the parent of all archive members - main_input_fp -> in_fp_parent, likewise - file_name -> in_file_name, likewise We add one new member, cu_mapped. Finally, we move the various frees of things like mapping table data to the top-level ctf_link, since deduplicating links will want to do that too. include/ * ctf-api.h (ECTF_NEEDSBFD): New. (ECTF_NERR): Adjust. (ctf_link): Rename share_mode arg to flags. libctf/ * Makefile.am: Set -DNOBFD=1 in libctf-nobfd, and =0 elsewhere. * Makefile.in: Regenerated. * ctf-impl.h (ctf_link_input_name): New. (ctf_file_t) <ctf_link_flags>: New. * ctf-create.c (ctf_serialize): Adjust accordingly. * ctf-link.c: Define ctf_open as weak when PIC. (ctf_arc_close_thunk): Remove unnecessary thunk. (ctf_file_close_thunk): Likewise. (ctf_link_input_name): New. (ctf_link_input_t): New value of the ctf_file_t.ctf_link_input. (ctf_link_input_close): Adjust accordingly. (ctf_link_add_ctf_internal): New, split from... (ctf_link_add_ctf): ... here. Return error if lazy loading of CTF is not possible. Change to just call... (ctf_link_add): ... this new function. (ctf_link_add_cu_mapping): Transition to ctf_err_warn. Drop the ctf_file_close_thunk. (ctf_link_in_member_cb_arg_t) <file_name> Rename to... <in_file_name>: ... this. <arcname>: Drop. <share_mode>: Likewise (migrated to ctf_link_flags). <done_main_member>: Rename to... <done_parent>: ... this. <main_input_fp>: Rename to... <in_fp_parent>: ... this. <cu_mapped>: New. (ctf_link_one_type): Adjuwt accordingly. Transition to ctf_err_warn, removing a TODO. (ctf_link_one_variable): Note a case too common to warn about. Report in the debug stream if a cu-mapped link prevents addition of a conflicting variable. (ctf_link_one_input_archive_member): Adjust. (ctf_link_lazy_open): New, open a CTF archive for linking when needed. (ctf_link_close_one_input_archive): New, close it again. (ctf_link_one_input_archive): Adjust for lazy opening, member renames, and ctf_err_warn transition. Move the empty_link_type_mapping call to... (ctf_link): ... here. Adjut for renamings and thunk removal. Don't spuriously fail if some input contains no CTF data. (ctf_link_write): ctf_err_warn transition. * libctf.ver: Remove not-yet-stable comment.
2020-06-05 02:28:52 +08:00
#define ECTF_NERR (ECTF_NEEDSBFD - ECTF_BASE + 1) /* Count of CTF errors. */
libctf: restructure error handling to reduce relocations Jose Marchesi noted that the traditional-Unix error array in ctf-error.c introduces one reloc per error to initialize the array: 58 so far. We can reduce this to zero using an array of carefully-sized individual members which is used to construct a string table, that is then referenced by the lookup functions: but doing this automatically is a pain. Bruno Haible wrote suitable code years ago: I got permission to reuse it (Bruno says "... which I hereby put in the public domain"); I modified it a tiny bit (similarly to what Ulrich Drepper did in the dsohowto text, but I redid it from scratch), commented it up a bit, and shifted the error table into that form, migrating it into the new file ctf-error.h. This has the advantage that it spotted both typos in the text of the errors in the comments in ctf-api.h and typos in the error defines in the comments in ctf-error.c, and places where the two were simply not in sync. All are now fixed. One new constant exists in ctf-api.h: CTF_NERR, since the old method of working out the number of errors in ctf-error.c was no longer usable, and it seems that the number of CTF errors is something users might reasonably want as well. It should be pretty easy to keep up to date as new errors are introduced. include/ * ctf-api.h (ECTF_*): Improve comments. (ECTF_NERR): New. libctf/ * ctf-error.c: Include <stddef.h>, for offsetof. (_ctf_errlist): Migrate to... (_ctf_errlist_t): ... this. (_ctf_erridx): New, indexes into _ctf_errlist_t. (_ctf_nerr): Remove. (ctf_errmsg): Adjust accordingly. * Makefile.am (BUILT_SOURCES): Note... (ctf-error.h): ... this new rule. * Makefile.in: Regenerate. * mkerrors.sed: New, process ctf-api.h to generate ctf-error.h. * .gitignore: New, ignore ctf-error.h.
2020-06-03 02:07:08 +08:00
/* The CTF data model is inferred to be the caller's data model or the data
model of the given object, unless ctf_setmodel() is explicitly called. */
#define CTF_MODEL_ILP32 1 /* Object data model is ILP32. */
#define CTF_MODEL_LP64 2 /* Object data model is LP64. */
#ifdef _LP64
# define CTF_MODEL_NATIVE CTF_MODEL_LP64
#else
# define CTF_MODEL_NATIVE CTF_MODEL_ILP32
#endif
/* Dynamic CTF containers can be created using ctf_create(). The ctf_add_*
routines can be used to add new definitions to the dynamic container.
New types are labeled as root or non-root to determine whether they are
visible at the top-level program scope when subsequently doing a lookup. */
#define CTF_ADD_NONROOT 0 /* Type only visible in nested scope. */
#define CTF_ADD_ROOT 1 /* Type visible at top-level scope. */
libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf_*_iter functions that take a callback and an arg and repeatedly call it. This *works*, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The *_next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t *i = NULL; int *hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t *i = NULL; ssize_t offset; const char *name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { /* do something with offset, name, and membtype */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf_*_next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. */ ssize_t ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, const char **name, ctf_id_t *membtype); /* Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. */ const char * ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, int *val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. */ ctf_file_t * ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name, int skip_parent, int *errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.
2020-06-03 22:13:24 +08:00
/* These typedefs are used to define the signature for callback functions that
can be used with the iteration and visit functions below. There is also a
family of iteration functions that do not require callbacks. */
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
typedef int ctf_visit_f (const char *name, ctf_id_t type, unsigned long offset,
int depth, void *arg);
typedef int ctf_member_f (const char *name, ctf_id_t membtype,
unsigned long offset, void *arg);
typedef int ctf_enum_f (const char *name, int val, void *arg);
typedef int ctf_variable_f (const char *name, ctf_id_t type, void *arg);
typedef int ctf_type_f (ctf_id_t type, void *arg);
typedef int ctf_type_all_f (ctf_id_t type, int flag, void *arg);
typedef int ctf_label_f (const char *name, const ctf_lblinfo_t *info,
void *arg);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
typedef int ctf_archive_member_f (ctf_file_t *fp, const char *name, void *arg);
typedef int ctf_archive_raw_member_f (const char *name, const void *content,
size_t len, void *arg);
typedef char *ctf_dump_decorate_f (ctf_sect_names_t sect,
char *line, void *arg);
typedef struct ctf_dump_state ctf_dump_state_t;
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf_*_iter functions that take a callback and an arg and repeatedly call it. This *works*, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The *_next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t *i = NULL; int *hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t *i = NULL; ssize_t offset; const char *name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { /* do something with offset, name, and membtype */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf_*_next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. */ ssize_t ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, const char **name, ctf_id_t *membtype); /* Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. */ const char * ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, int *val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. */ ctf_file_t * ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name, int skip_parent, int *errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.
2020-06-03 22:13:24 +08:00
/* Iteration state for the _next() functions, and allocators/copiers/freers for
it. (None of these are needed for the simple case of iterating to the end:
the _next() function allocate and free the iterators for you.) */
typedef struct ctf_next ctf_next_t;
extern ctf_next_t *ctf_next_create (void);
extern void ctf_next_destroy (ctf_next_t *);
extern ctf_next_t *ctf_next_copy (ctf_next_t *);
/* Opening. These mostly return an abstraction over both CTF files and CTF
archives: so they can be used to open both. CTF files will appear to be an
archive with one member named '.ctf'. The low-level functions
ctf_simple_open() and ctf_bufopen() return ctf_file_t's directly, and cannot
be used on CTF archives. */
extern ctf_archive_t *ctf_bfdopen (struct bfd *, int *);
extern ctf_archive_t *ctf_bfdopen_ctfsect (struct bfd *, const ctf_sect_t *,
int *);
extern ctf_archive_t *ctf_fdopen (int fd, const char *filename,
const char *target, int *errp);
extern ctf_archive_t *ctf_open (const char *filename,
const char *target, int *errp);
extern void ctf_close (ctf_archive_t *);
libctf: opening This fills in the other half of the opening/creation puzzle: opening of already-existing CTF files. Such files are always read-only: if you want to add to a CTF file opened with one of the opening functions in this file, use ctf_add_type(), in a later commit, to copy appropriate types into a newly ctf_create()d, writable container. The lowest-level opening functions are in here: ctf_bufopen(), which takes ctf_sect_t structures akin to ELF section headers, and ctf_simple_open(), which can be used if you don't have an entire ELF section header to work from. Both will malloc() new space for the buffers only if necessary, will mmap() directly from the file if requested, and will mprotect() it afterwards to prevent accidental corruption of the types. These functions are also used by ctf_update() when converting types in a writable container into read-only types that can be looked up using the lookup functions (in later commits). The files are always of the native endianness of the system that created them: at read time, the endianness of the header magic number is used to determine whether or not the file needs byte-swapping, and the entire thing is aggressively byte-swapped. The agggressive nature of this swapping avoids complicating the rest of the code with endianness conversions, while the native endianness introduces no byte-swapping overhead in the common case. (The endianness-independence code is also much newer than everything else in this file, and deserves closer scrutiny.) The accessors at the top of the file are there to transparently support older versions of the CTF file format, allowing translation from older formats that have different sizes for the structures in ctf.h: currently, these older formats are intermingled with the newer ones in ctf.h: they will probably migrate to a compatibility header in time, to ease readability. The ctf_set_base() function is split out for the same reason: when conversion code to a newer format is written, it would need to malloc() new storage for the entire ctf_file_t if a file format change causes it to grow, and for that we need ctf_set_base() to be a separate function. One pair of linked data structures supported by this file has no creation code in libctf yet: the data and function object sections read by init_symtab(). These will probably arrive soon, when the linker comes to need them. (init_symtab() has hardly been changed since 2009, but if any code in libctf has rotted over time, this will.) A few simple accessors are also present that can even be called on read-only containers because they don't actually modify them, since the relevant things are not stored in the container but merely change its operation: ctf_setmodel(), which lets you specify whether a container is LP64 or not (used to statically determine the sizes of a few types), ctf_import(), which is the only way to associate a parent container with a child container, and ctf_setspecific(), which lets the caller associate an arbitrary pointer with the CTF container for any use. If the user doesn't call these functions correctly, libctf will misbehave: this is particularly important for ctf_import(), since a container built against a given parent container will not be able to resolve types that depend on types in the parent unless it is ctf_import()ed with a parent container with the same set of types at the same IDs, or a superset. Possible future extensions (also noted in the ctf-hash.c file) include storing a count of things so that we don't need to do one pass over the CTF file counting everything, and computing a perfect hash at CTF creation time in some compact form, storing it in the CTF file, and using it to hash things so we don't need to do a second pass over the entire CTF file to set up the hashes used to go from names to type IDs. (There are multiple such hashes, one for each C type namespace: types, enums, structs, and unions.) libctf/ * ctf-open.c: New file. * swap.h: Likewise. include/ * ctf-api.h (ctf_file_close): New declaration. (ctf_getdatasect): Likewise. (ctf_parent_file): Likewise. (ctf_parent_name): Likewise. (ctf_parent_name_set): Likewise. (ctf_import): Likewise. (ctf_setmodel): Likewise. (ctf_getmodel): Likewise. (ctf_setspecific): Likewise. (ctf_getspecific): Likewise.
2019-04-24 17:17:13 +08:00
extern ctf_sect_t ctf_getdatasect (const ctf_file_t *);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
extern ctf_archive_t *ctf_get_arc (const ctf_file_t *);
extern ctf_archive_t *ctf_arc_open (const char *, int *);
libctf, binutils: support CTF archives like objdump objdump and readelf have one major CTF-related behavioural difference: objdump can read .ctf sections that contain CTF archives and extract and dump their members, while readelf cannot. Since the linker often emits CTF archives, this means that readelf intermittently and (from the user's perspective) randomly fails to read CTF in files that ld emits, with a confusing error message wrongly claiming that the CTF content is corrupt. This is purely because the archive-opening code in libctf was needlessly tangled up with the BFD code, so readelf couldn't use it. Here, we disentangle it, moving ctf_new_archive_internal from ctf-open-bfd.c into ctf-archive.c and merging it with the helper function in ctf-archive.c it was already using. We add a new public API function ctf_arc_bufopen, that looks very like ctf_bufopen but returns an archive given suitable section data rather than a ctf_file_t: the archive is a ctf_archive_t, so it can be called on raw CTF dictionaries (with no archive present) and will return a single-member synthetic "archive". There is a tiny lifetime tweak here: before now, the archive code could assume that the symbol section in the ctf_archive_internal wrapper structure was always owned by BFD if it was present and should always be freed: now, the caller can pass one in via ctf_arc_bufopen, wihch has the usual lifetime rules for such sections (caller frees): so we add an extra field to track whether this is an internal call from ctf-open-bfd, in which case we still free the symbol section. include/ * ctf-api.h (ctf_arc_bufopen): New. libctf/ * ctf-impl.h (ctf_new_archive_internal): Declare. (ctf_arc_bufopen): Remove. (ctf_archive_internal) <ctfi_free_symsect>: New. * ctf-archive.c (ctf_arc_close): Use it. (ctf_arc_bufopen): Fuse into... (ctf_new_archive_internal): ... this, moved across from... * ctf-open-bfd.c: ... here. (ctf_bfdopen_ctfsect): Use ctf_arc_bufopen. * libctf.ver: Add it. binutils/ * readelf.c (dump_section_as_ctf): Support .ctf archives using ctf_arc_bufopen. Automatically load the .ctf member of such archives as the parent of all other members, unless specifically overridden via --ctf-parent. Split out dumping code into... (dump_ctf_archive_member): ... here, as in objdump, and call it once per archive member. (dump_ctf_indent_lines): Code style fix.
2019-12-13 20:01:12 +08:00
extern ctf_archive_t *ctf_arc_bufopen (const ctf_sect_t *,
const ctf_sect_t *,
const ctf_sect_t *,
int *);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
extern void ctf_arc_close (ctf_archive_t *);
extern ctf_file_t *ctf_arc_open_by_name (const ctf_archive_t *,
const char *, int *);
extern ctf_file_t *ctf_arc_open_by_name_sections (const ctf_archive_t *,
const ctf_sect_t *,
const ctf_sect_t *,
const char *, int *);
extern size_t ctf_archive_count (const ctf_archive_t *);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
/* The next functions return or close real CTF files, or write out CTF archives,
not opaque containers around either. */
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
2019-04-24 05:45:46 +08:00
extern ctf_file_t *ctf_simple_open (const char *, size_t, const char *, size_t,
size_t, const char *, size_t, int *);
extern ctf_file_t *ctf_bufopen (const ctf_sect_t *, const ctf_sect_t *,
const ctf_sect_t *, int *);
extern void ctf_ref (ctf_file_t *);
libctf: opening This fills in the other half of the opening/creation puzzle: opening of already-existing CTF files. Such files are always read-only: if you want to add to a CTF file opened with one of the opening functions in this file, use ctf_add_type(), in a later commit, to copy appropriate types into a newly ctf_create()d, writable container. The lowest-level opening functions are in here: ctf_bufopen(), which takes ctf_sect_t structures akin to ELF section headers, and ctf_simple_open(), which can be used if you don't have an entire ELF section header to work from. Both will malloc() new space for the buffers only if necessary, will mmap() directly from the file if requested, and will mprotect() it afterwards to prevent accidental corruption of the types. These functions are also used by ctf_update() when converting types in a writable container into read-only types that can be looked up using the lookup functions (in later commits). The files are always of the native endianness of the system that created them: at read time, the endianness of the header magic number is used to determine whether or not the file needs byte-swapping, and the entire thing is aggressively byte-swapped. The agggressive nature of this swapping avoids complicating the rest of the code with endianness conversions, while the native endianness introduces no byte-swapping overhead in the common case. (The endianness-independence code is also much newer than everything else in this file, and deserves closer scrutiny.) The accessors at the top of the file are there to transparently support older versions of the CTF file format, allowing translation from older formats that have different sizes for the structures in ctf.h: currently, these older formats are intermingled with the newer ones in ctf.h: they will probably migrate to a compatibility header in time, to ease readability. The ctf_set_base() function is split out for the same reason: when conversion code to a newer format is written, it would need to malloc() new storage for the entire ctf_file_t if a file format change causes it to grow, and for that we need ctf_set_base() to be a separate function. One pair of linked data structures supported by this file has no creation code in libctf yet: the data and function object sections read by init_symtab(). These will probably arrive soon, when the linker comes to need them. (init_symtab() has hardly been changed since 2009, but if any code in libctf has rotted over time, this will.) A few simple accessors are also present that can even be called on read-only containers because they don't actually modify them, since the relevant things are not stored in the container but merely change its operation: ctf_setmodel(), which lets you specify whether a container is LP64 or not (used to statically determine the sizes of a few types), ctf_import(), which is the only way to associate a parent container with a child container, and ctf_setspecific(), which lets the caller associate an arbitrary pointer with the CTF container for any use. If the user doesn't call these functions correctly, libctf will misbehave: this is particularly important for ctf_import(), since a container built against a given parent container will not be able to resolve types that depend on types in the parent unless it is ctf_import()ed with a parent container with the same set of types at the same IDs, or a superset. Possible future extensions (also noted in the ctf-hash.c file) include storing a count of things so that we don't need to do one pass over the CTF file counting everything, and computing a perfect hash at CTF creation time in some compact form, storing it in the CTF file, and using it to hash things so we don't need to do a second pass over the entire CTF file to set up the hashes used to go from names to type IDs. (There are multiple such hashes, one for each C type namespace: types, enums, structs, and unions.) libctf/ * ctf-open.c: New file. * swap.h: Likewise. include/ * ctf-api.h (ctf_file_close): New declaration. (ctf_getdatasect): Likewise. (ctf_parent_file): Likewise. (ctf_parent_name): Likewise. (ctf_parent_name_set): Likewise. (ctf_import): Likewise. (ctf_setmodel): Likewise. (ctf_getmodel): Likewise. (ctf_setspecific): Likewise. (ctf_getspecific): Likewise.
2019-04-24 17:17:13 +08:00
extern void ctf_file_close (ctf_file_t *);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
extern int ctf_arc_write (const char *, ctf_file_t **, size_t,
const char **, size_t);
extern int ctf_arc_write_fd (int, ctf_file_t **, size_t, const char **,
size_t);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
libctf: allow the header to change between versions libctf supports dynamic upgrading of the type table as file format versions change, but before now has not supported changes to the CTF header. Doing this is complicated by the baroque storage method used: the CTF header is kept prepended to the rest of the CTF data, just as when read from the file, and written out from there, and is endian-flipped in place. This makes accessing it needlessly hard and makes it almost impossible to make the header larger if we add fields. The general storage machinery around the malloced ctf pointer (the 'ctf_base') is also overcomplicated: the pointer is sometimes malloced locally and sometimes assigned from a parameter, so freeing it requires checking to see if that parameter was used, needlessly coupling ctf_bufopen and ctf_file_close together. So split the header out into a new ctf_file_t.ctf_header, which is written out explicitly: squeeze it out of the CTF buffer whenever we reallocate it, and use ctf_file_t.ctf_buf to skip past the header when we do not need to reallocate (when no upgrading or endian-flipping is required). We now track whether the CTF base can be freed explicitly via a new ctf_dynbase pointer which is non-NULL only when freeing is possible. With all this done, we can upgrade the header on the fly and add new fields as desired, via a new upgrade_header function in ctf-open. As with other forms of upgrading, libctf upgrades older headers automatically to the latest supported version at open time. For a first use of this field, we add a new string field cth_cuname, and a corresponding setter/getter pair ctf_cuname_set and ctf_cuname: this is used by debuggers to determine whether a CTF section's types relate to a single compilation unit, or to all compilation units in the program. (Types with ambiguous definitions in different CUs have only one of these types placed in the top-level shared .ctf container: the rest are placed in much smaller per-CU containers, which have the shared container as their parent. Since CTF must be useful in the absence of DWARF, we store the names of the relevant CUs ourselves, so the debugger can look them up.) v5: fix tabdamage. include/ * ctf-api.h (ctf_cuname): New function. (ctf_cuname_set): Likewise. * ctf.h: Improve comment around upgrading, no longer implying that v2 is the target of upgrades (it is v3 now). (ctf_header_v2_t): New, old-format header for backward compatibility. (ctf_header_t): Add cth_cuname: this is the first of several header changes in format v3. libctf/ * ctf-impl.h (ctf_file_t): New fields ctf_header, ctf_dynbase, ctf_cuname, ctf_dyncuname: ctf_base and ctf_buf are no longer const. * ctf-open.c (ctf_set_base): Preserve the gap between ctf_buf and ctf_base: do not assume that it is always sizeof (ctf_header_t). Print out ctf_cuname: only print out ctf_parname if set. (ctf_free_base): Removed, ctf_base is no longer freed: free ctf_dynbase instead. (ctf_set_version): Fix spacing. (upgrade_header): New, in-place header upgrading. (upgrade_types): Rename to... (upgrade_types_v1): ... this. Free ctf_dynbase, not ctf_base. No longer track old and new headers separately. No longer allow for header sizes explicitly: squeeze the headers out on upgrade (they are preserved in fp->ctf_header). Set ctf_dynbase, ctf_base and ctf_buf explicitly. Use ctf_free, not ctf_free_base. (upgrade_types): New, also handle ctf_parmax updating. (flip_header): Flip ctf_cuname. (flip_types): Flip BUF explicitly rather than deriving BUF from BASE. (ctf_bufopen): Store the header in fp->ctf_header. Correct minimum required alignment of objtoff and funcoff. No longer store it in the ctf_buf unless that buf is derived unmodified from the input. Set ctf_dynbase where ctf_base is dynamically allocated. Drop locals that duplicate fields in ctf_file: move allocation of ctf_file further up instead. Call upgrade_header as needed. Move version-specific ctf_parmax initialization into upgrade_types. More concise error handling. (ctf_file_close): No longer test for null pointers before freeing. Free ctf_dyncuname, ctf_dynbase, and ctf_header. Do not call ctf_free_base. (ctf_cuname): New. (ctf_cuname_set): New. * ctf-create.c (ctf_update): Populate ctf_cuname. (ctf_gzwrite): Write out the header explicitly. Remove obsolescent comment. (ctf_write): Likewise. (ctf_compress_write): Get the header from ctf_header, not ctf_base. Fix the compression length: fp->ctf_size never counted the CTF header. Simplify the compress call accordingly.
2019-07-07 00:36:21 +08:00
extern const char *ctf_cuname (ctf_file_t *);
libctf: remove ctf_malloc, ctf_free and ctf_strdup These just get in the way of auditing for erroneous usage of strdup and add a huge irregular surface of "ctf_malloc or malloc? ctf_free or free? ctf_strdup or strdup?" ctf_malloc and ctf_free usage has not reliably matched up for many years, if ever, making the whole game pointless. Go back to malloc, free, and strdup like everyone else: while we're at it, fix a bunch of places where we weren't properly checking for OOM. This changes the interface of ctf_cuname_set and ctf_parent_name_set, which could strdup but could not return errors (like ENOMEM). New in v4. include/ * ctf-api.h (ctf_cuname_set): Can now fail, returning int. (ctf_parent_name_set): Likewise. libctf/ * ctf-impl.h (ctf_alloc): Remove. (ctf_free): Likewise. (ctf_strdup): Likewise. * ctf-subr.c (ctf_alloc): Remove. (ctf_free): Likewise. * ctf-util.c (ctf_strdup): Remove. * ctf-create.c (ctf_serialize): Use malloc, not ctf_alloc; free, not ctf_free; strdup, not ctf_strdup. (ctf_dtd_delete): Likewise. (ctf_dvd_delete): Likewise. (ctf_add_generic): Likewise. (ctf_add_function): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_variable): Likewise. (membadd): Likewise. (ctf_compress_write): Likewise. (ctf_write_mem): Likewise. * ctf-decl.c (ctf_decl_push): Likewise. (ctf_decl_fini): Likewise. (ctf_decl_sprintf): Likewise. Check for OOM. * ctf-dump.c (ctf_dump_append): Use malloc, not ctf_alloc; free, not ctf_free; strdup, not ctf_strdup. (ctf_dump_free): Likewise. (ctf_dump): Likewise. * ctf-open.c (upgrade_types_v1): Likewise. (init_types): Likewise. (ctf_file_close): Likewise. (ctf_bufopen_internal): Likewise. Check for OOM. (ctf_parent_name_set): Likewise: report the OOM to the caller. (ctf_cuname_set): Likewise. (ctf_import): Likewise. * ctf-string.c (ctf_str_purge_atom_refs): Use malloc, not ctf_alloc; free, not ctf_free; strdup, not ctf_strdup. (ctf_str_free_atom): Likewise. (ctf_str_create_atoms): Likewise. (ctf_str_add_ref_internal): Likewise. (ctf_str_remove_ref): Likewise. (ctf_str_write_strtab): Likewise.
2019-09-17 13:54:23 +08:00
extern int ctf_cuname_set (ctf_file_t *, const char *);
libctf: opening This fills in the other half of the opening/creation puzzle: opening of already-existing CTF files. Such files are always read-only: if you want to add to a CTF file opened with one of the opening functions in this file, use ctf_add_type(), in a later commit, to copy appropriate types into a newly ctf_create()d, writable container. The lowest-level opening functions are in here: ctf_bufopen(), which takes ctf_sect_t structures akin to ELF section headers, and ctf_simple_open(), which can be used if you don't have an entire ELF section header to work from. Both will malloc() new space for the buffers only if necessary, will mmap() directly from the file if requested, and will mprotect() it afterwards to prevent accidental corruption of the types. These functions are also used by ctf_update() when converting types in a writable container into read-only types that can be looked up using the lookup functions (in later commits). The files are always of the native endianness of the system that created them: at read time, the endianness of the header magic number is used to determine whether or not the file needs byte-swapping, and the entire thing is aggressively byte-swapped. The agggressive nature of this swapping avoids complicating the rest of the code with endianness conversions, while the native endianness introduces no byte-swapping overhead in the common case. (The endianness-independence code is also much newer than everything else in this file, and deserves closer scrutiny.) The accessors at the top of the file are there to transparently support older versions of the CTF file format, allowing translation from older formats that have different sizes for the structures in ctf.h: currently, these older formats are intermingled with the newer ones in ctf.h: they will probably migrate to a compatibility header in time, to ease readability. The ctf_set_base() function is split out for the same reason: when conversion code to a newer format is written, it would need to malloc() new storage for the entire ctf_file_t if a file format change causes it to grow, and for that we need ctf_set_base() to be a separate function. One pair of linked data structures supported by this file has no creation code in libctf yet: the data and function object sections read by init_symtab(). These will probably arrive soon, when the linker comes to need them. (init_symtab() has hardly been changed since 2009, but if any code in libctf has rotted over time, this will.) A few simple accessors are also present that can even be called on read-only containers because they don't actually modify them, since the relevant things are not stored in the container but merely change its operation: ctf_setmodel(), which lets you specify whether a container is LP64 or not (used to statically determine the sizes of a few types), ctf_import(), which is the only way to associate a parent container with a child container, and ctf_setspecific(), which lets the caller associate an arbitrary pointer with the CTF container for any use. If the user doesn't call these functions correctly, libctf will misbehave: this is particularly important for ctf_import(), since a container built against a given parent container will not be able to resolve types that depend on types in the parent unless it is ctf_import()ed with a parent container with the same set of types at the same IDs, or a superset. Possible future extensions (also noted in the ctf-hash.c file) include storing a count of things so that we don't need to do one pass over the CTF file counting everything, and computing a perfect hash at CTF creation time in some compact form, storing it in the CTF file, and using it to hash things so we don't need to do a second pass over the entire CTF file to set up the hashes used to go from names to type IDs. (There are multiple such hashes, one for each C type namespace: types, enums, structs, and unions.) libctf/ * ctf-open.c: New file. * swap.h: Likewise. include/ * ctf-api.h (ctf_file_close): New declaration. (ctf_getdatasect): Likewise. (ctf_parent_file): Likewise. (ctf_parent_name): Likewise. (ctf_parent_name_set): Likewise. (ctf_import): Likewise. (ctf_setmodel): Likewise. (ctf_getmodel): Likewise. (ctf_setspecific): Likewise. (ctf_getspecific): Likewise.
2019-04-24 17:17:13 +08:00
extern ctf_file_t *ctf_parent_file (ctf_file_t *);
extern const char *ctf_parent_name (ctf_file_t *);
libctf: remove ctf_malloc, ctf_free and ctf_strdup These just get in the way of auditing for erroneous usage of strdup and add a huge irregular surface of "ctf_malloc or malloc? ctf_free or free? ctf_strdup or strdup?" ctf_malloc and ctf_free usage has not reliably matched up for many years, if ever, making the whole game pointless. Go back to malloc, free, and strdup like everyone else: while we're at it, fix a bunch of places where we weren't properly checking for OOM. This changes the interface of ctf_cuname_set and ctf_parent_name_set, which could strdup but could not return errors (like ENOMEM). New in v4. include/ * ctf-api.h (ctf_cuname_set): Can now fail, returning int. (ctf_parent_name_set): Likewise. libctf/ * ctf-impl.h (ctf_alloc): Remove. (ctf_free): Likewise. (ctf_strdup): Likewise. * ctf-subr.c (ctf_alloc): Remove. (ctf_free): Likewise. * ctf-util.c (ctf_strdup): Remove. * ctf-create.c (ctf_serialize): Use malloc, not ctf_alloc; free, not ctf_free; strdup, not ctf_strdup. (ctf_dtd_delete): Likewise. (ctf_dvd_delete): Likewise. (ctf_add_generic): Likewise. (ctf_add_function): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_variable): Likewise. (membadd): Likewise. (ctf_compress_write): Likewise. (ctf_write_mem): Likewise. * ctf-decl.c (ctf_decl_push): Likewise. (ctf_decl_fini): Likewise. (ctf_decl_sprintf): Likewise. Check for OOM. * ctf-dump.c (ctf_dump_append): Use malloc, not ctf_alloc; free, not ctf_free; strdup, not ctf_strdup. (ctf_dump_free): Likewise. (ctf_dump): Likewise. * ctf-open.c (upgrade_types_v1): Likewise. (init_types): Likewise. (ctf_file_close): Likewise. (ctf_bufopen_internal): Likewise. Check for OOM. (ctf_parent_name_set): Likewise: report the OOM to the caller. (ctf_cuname_set): Likewise. (ctf_import): Likewise. * ctf-string.c (ctf_str_purge_atom_refs): Use malloc, not ctf_alloc; free, not ctf_free; strdup, not ctf_strdup. (ctf_str_free_atom): Likewise. (ctf_str_create_atoms): Likewise. (ctf_str_add_ref_internal): Likewise. (ctf_str_remove_ref): Likewise. (ctf_str_write_strtab): Likewise.
2019-09-17 13:54:23 +08:00
extern int ctf_parent_name_set (ctf_file_t *, const char *);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern int ctf_type_isparent (ctf_file_t *, ctf_id_t);
extern int ctf_type_ischild (ctf_file_t *, ctf_id_t);
libctf: opening This fills in the other half of the opening/creation puzzle: opening of already-existing CTF files. Such files are always read-only: if you want to add to a CTF file opened with one of the opening functions in this file, use ctf_add_type(), in a later commit, to copy appropriate types into a newly ctf_create()d, writable container. The lowest-level opening functions are in here: ctf_bufopen(), which takes ctf_sect_t structures akin to ELF section headers, and ctf_simple_open(), which can be used if you don't have an entire ELF section header to work from. Both will malloc() new space for the buffers only if necessary, will mmap() directly from the file if requested, and will mprotect() it afterwards to prevent accidental corruption of the types. These functions are also used by ctf_update() when converting types in a writable container into read-only types that can be looked up using the lookup functions (in later commits). The files are always of the native endianness of the system that created them: at read time, the endianness of the header magic number is used to determine whether or not the file needs byte-swapping, and the entire thing is aggressively byte-swapped. The agggressive nature of this swapping avoids complicating the rest of the code with endianness conversions, while the native endianness introduces no byte-swapping overhead in the common case. (The endianness-independence code is also much newer than everything else in this file, and deserves closer scrutiny.) The accessors at the top of the file are there to transparently support older versions of the CTF file format, allowing translation from older formats that have different sizes for the structures in ctf.h: currently, these older formats are intermingled with the newer ones in ctf.h: they will probably migrate to a compatibility header in time, to ease readability. The ctf_set_base() function is split out for the same reason: when conversion code to a newer format is written, it would need to malloc() new storage for the entire ctf_file_t if a file format change causes it to grow, and for that we need ctf_set_base() to be a separate function. One pair of linked data structures supported by this file has no creation code in libctf yet: the data and function object sections read by init_symtab(). These will probably arrive soon, when the linker comes to need them. (init_symtab() has hardly been changed since 2009, but if any code in libctf has rotted over time, this will.) A few simple accessors are also present that can even be called on read-only containers because they don't actually modify them, since the relevant things are not stored in the container but merely change its operation: ctf_setmodel(), which lets you specify whether a container is LP64 or not (used to statically determine the sizes of a few types), ctf_import(), which is the only way to associate a parent container with a child container, and ctf_setspecific(), which lets the caller associate an arbitrary pointer with the CTF container for any use. If the user doesn't call these functions correctly, libctf will misbehave: this is particularly important for ctf_import(), since a container built against a given parent container will not be able to resolve types that depend on types in the parent unless it is ctf_import()ed with a parent container with the same set of types at the same IDs, or a superset. Possible future extensions (also noted in the ctf-hash.c file) include storing a count of things so that we don't need to do one pass over the CTF file counting everything, and computing a perfect hash at CTF creation time in some compact form, storing it in the CTF file, and using it to hash things so we don't need to do a second pass over the entire CTF file to set up the hashes used to go from names to type IDs. (There are multiple such hashes, one for each C type namespace: types, enums, structs, and unions.) libctf/ * ctf-open.c: New file. * swap.h: Likewise. include/ * ctf-api.h (ctf_file_close): New declaration. (ctf_getdatasect): Likewise. (ctf_parent_file): Likewise. (ctf_parent_name): Likewise. (ctf_parent_name_set): Likewise. (ctf_import): Likewise. (ctf_setmodel): Likewise. (ctf_getmodel): Likewise. (ctf_setspecific): Likewise. (ctf_getspecific): Likewise.
2019-04-24 17:17:13 +08:00
extern int ctf_import (ctf_file_t *, ctf_file_t *);
extern int ctf_setmodel (ctf_file_t *, int);
extern int ctf_getmodel (ctf_file_t *);
extern void ctf_setspecific (ctf_file_t *, void *);
extern void *ctf_getspecific (ctf_file_t *);
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
2019-04-24 05:45:46 +08:00
extern int ctf_errno (ctf_file_t *);
extern const char *ctf_errmsg (int);
extern int ctf_version (int);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern int ctf_func_info (ctf_file_t *, unsigned long, ctf_funcinfo_t *);
extern int ctf_func_args (ctf_file_t *, unsigned long, uint32_t, ctf_id_t *);
extern int ctf_func_type_info (ctf_file_t *, ctf_id_t, ctf_funcinfo_t *);
extern int ctf_func_type_args (ctf_file_t *, ctf_id_t, uint32_t, ctf_id_t *);
extern ctf_id_t ctf_lookup_by_name (ctf_file_t *, const char *);
extern ctf_id_t ctf_lookup_by_symbol (ctf_file_t *, unsigned long);
extern ctf_id_t ctf_lookup_variable (ctf_file_t *, const char *);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern ctf_id_t ctf_type_resolve (ctf_file_t *, ctf_id_t);
extern char *ctf_type_aname (ctf_file_t *, ctf_id_t);
extern char *ctf_type_aname_raw (ctf_file_t *, ctf_id_t);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern ssize_t ctf_type_lname (ctf_file_t *, ctf_id_t, char *, size_t);
extern char *ctf_type_name (ctf_file_t *, ctf_id_t, char *, size_t);
extern const char *ctf_type_name_raw (ctf_file_t *, ctf_id_t);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern ssize_t ctf_type_size (ctf_file_t *, ctf_id_t);
extern ssize_t ctf_type_align (ctf_file_t *, ctf_id_t);
extern int ctf_type_kind (ctf_file_t *, ctf_id_t);
extern int ctf_type_kind_forwarded (ctf_file_t *, ctf_id_t);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern ctf_id_t ctf_type_reference (ctf_file_t *, ctf_id_t);
extern ctf_id_t ctf_type_pointer (ctf_file_t *, ctf_id_t);
extern int ctf_type_encoding (ctf_file_t *, ctf_id_t, ctf_encoding_t *);
extern int ctf_type_visit (ctf_file_t *, ctf_id_t, ctf_visit_f *, void *);
extern int ctf_type_cmp (ctf_file_t *, ctf_id_t, ctf_file_t *, ctf_id_t);
extern int ctf_type_compat (ctf_file_t *, ctf_id_t, ctf_file_t *, ctf_id_t);
extern int ctf_member_info (ctf_file_t *, ctf_id_t, const char *,
ctf_membinfo_t *);
extern int ctf_array_info (ctf_file_t *, ctf_id_t, ctf_arinfo_t *);
extern const char *ctf_enum_name (ctf_file_t *, ctf_id_t, int);
extern int ctf_enum_value (ctf_file_t *, ctf_id_t, const char *, int *);
extern void ctf_label_set (ctf_file_t *, const char *);
extern const char *ctf_label_get (ctf_file_t *);
extern const char *ctf_label_topmost (ctf_file_t *);
extern int ctf_label_info (ctf_file_t *, const char *, ctf_lblinfo_t *);
extern int ctf_member_count (ctf_file_t *, ctf_id_t);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern int ctf_member_iter (ctf_file_t *, ctf_id_t, ctf_member_f *, void *);
libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf_*_iter functions that take a callback and an arg and repeatedly call it. This *works*, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The *_next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t *i = NULL; int *hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t *i = NULL; ssize_t offset; const char *name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { /* do something with offset, name, and membtype */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf_*_next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. */ ssize_t ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, const char **name, ctf_id_t *membtype); /* Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. */ const char * ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, int *val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. */ ctf_file_t * ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name, int skip_parent, int *errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.
2020-06-03 22:13:24 +08:00
extern ssize_t ctf_member_next (ctf_file_t *, ctf_id_t, ctf_next_t **,
const char **name, ctf_id_t *membtype);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern int ctf_enum_iter (ctf_file_t *, ctf_id_t, ctf_enum_f *, void *);
libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf_*_iter functions that take a callback and an arg and repeatedly call it. This *works*, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The *_next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t *i = NULL; int *hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t *i = NULL; ssize_t offset; const char *name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { /* do something with offset, name, and membtype */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf_*_next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. */ ssize_t ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, const char **name, ctf_id_t *membtype); /* Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. */ const char * ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, int *val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. */ ctf_file_t * ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name, int skip_parent, int *errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.
2020-06-03 22:13:24 +08:00
extern const char *ctf_enum_next (ctf_file_t *, ctf_id_t, ctf_next_t **,
int *);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern int ctf_type_iter (ctf_file_t *, ctf_type_f *, void *);
extern int ctf_type_iter_all (ctf_file_t *, ctf_type_all_f *, void *);
libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf_*_iter functions that take a callback and an arg and repeatedly call it. This *works*, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The *_next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t *i = NULL; int *hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t *i = NULL; ssize_t offset; const char *name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { /* do something with offset, name, and membtype */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf_*_next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. */ ssize_t ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, const char **name, ctf_id_t *membtype); /* Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. */ const char * ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, int *val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. */ ctf_file_t * ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name, int skip_parent, int *errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.
2020-06-03 22:13:24 +08:00
extern ctf_id_t ctf_type_next (ctf_file_t *, ctf_next_t **,
int *flag, int want_hidden);
extern int ctf_label_iter (ctf_file_t *, ctf_label_f *, void *);
libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf_*_iter functions that take a callback and an arg and repeatedly call it. This *works*, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The *_next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t *i = NULL; int *hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t *i = NULL; ssize_t offset; const char *name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { /* do something with offset, name, and membtype */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf_*_next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. */ ssize_t ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, const char **name, ctf_id_t *membtype); /* Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. */ const char * ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, int *val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. */ ctf_file_t * ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name, int skip_parent, int *errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.
2020-06-03 22:13:24 +08:00
extern int ctf_label_next (ctf_file_t *, ctf_next_t **, const char **); /* TBD */
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
extern int ctf_variable_iter (ctf_file_t *, ctf_variable_f *, void *);
libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf_*_iter functions that take a callback and an arg and repeatedly call it. This *works*, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The *_next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t *i = NULL; int *hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t *i = NULL; ssize_t offset; const char *name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { /* do something with offset, name, and membtype */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf_*_next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. */ ssize_t ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, const char **name, ctf_id_t *membtype); /* Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. */ const char * ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, int *val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. */ ctf_file_t * ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name, int skip_parent, int *errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.
2020-06-03 22:13:24 +08:00
extern ctf_id_t ctf_variable_next (ctf_file_t *, ctf_next_t **,
const char **);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
extern int ctf_archive_iter (const ctf_archive_t *, ctf_archive_member_f *,
void *);
libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf_*_iter functions that take a callback and an arg and repeatedly call it. This *works*, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The *_next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t *i = NULL; int *hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t *i = NULL; ssize_t offset; const char *name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { /* do something with offset, name, and membtype */ } if (ctf_errno (fp) != ECTF_NEXT_END) /* iteration error */ Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf_*_next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. */ ssize_t ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, const char **name, ctf_id_t *membtype); /* Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. */ const char * ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it, int *val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. */ ctf_id_t ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. */ ctf_file_t * ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name, int skip_parent, int *errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.
2020-06-03 22:13:24 +08:00
extern ctf_file_t *ctf_archive_next (const ctf_archive_t *, ctf_next_t **,
const char **, int skip_parent, int *errp);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
/* This function alone does not currently operate on CTF files masquerading
as archives, and returns -EINVAL: the raw data is no longer available. It is
expected to be used only by archiving tools, in any case, which have no need
to deal with non-archives at all. */
extern int ctf_archive_raw_iter (const ctf_archive_t *,
ctf_archive_raw_member_f *, void *);
extern char *ctf_dump (ctf_file_t *, ctf_dump_state_t **state,
ctf_sect_names_t sect, ctf_dump_decorate_f *,
void *arg);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
libctf, ld, binutils: add textual error/warning reporting for libctf This commit adds a long-missing piece of infrastructure to libctf: the ability to report errors and warnings using all the power of printf, rather than being restricted to one errno value. Internally, libctf calls ctf_err_warn() to add errors and warnings to a list: a new iterator ctf_errwarning_next() then consumes this list one by one and hands it to the caller, which can free it. New errors and warnings are added until the list is consumed by the caller or the ctf_file_t is closed, so you can dump them at intervals. The caller can of course choose to print only those warnings it wants. (I am not sure whether we want objdump, readelf or ld to print warnings or not: right now I'm printing them, but maybe we only want to print errors? This entirely depends on whether warnings are voluminous things describing e.g. the inability to emit single types because of name clashes or something. There are no users of this infrastructure yet, so it's hard to say.) There is no internationalization here yet, but this at least adds a place where internationalization can be added, to one of ctf_errwarning_next or ctf_err_warn. We also provide a new ctf_assert() function which uses this infrastructure to provide non-fatal assertion failures while emitting an assert-like string to the caller: to save space and avoid needlessly duplicating unchanging strings, the assertion test is inlined but the print-things-out failure case is not. All assertions in libctf will be converted to use this machinery in future commits and propagate assertion-failure errors up, so that the linker in particular cannot be killed by libctf assertion failures when it could perfectly well just print warnings and drop the CTF section. include/ * ctf-api.h (ECTF_INTERNAL): Adjust error text. (ctf_errwarning_next): New. libctf/ * ctf-impl.h (ctf_assert): New. (ctf_err_warning_t): Likewise. (ctf_file_t) <ctf_errs_warnings>: Likewise. (ctf_err_warn): New prototype. (ctf_assert_fail_internal): Likewise. * ctf-inlines.h (ctf_assert_internal): Likewise. * ctf-open.c (ctf_file_close): Free ctf_errs_warnings. * ctf-create.c (ctf_serialize): Copy it on serialization. * ctf-subr.c (ctf_err_warn): New, add an error/warning. (ctf_errwarning_next): New iterator, free and pass back errors/warnings in succession. * libctf.ver (ctf_errwarning_next): Add. ld/ * ldlang.c (lang_ctf_errs_warnings): New, print CTF errors and warnings. Assert when libctf asserts. (lang_merge_ctf): Call it. (land_write_ctf): Likewise. binutils/ * objdump.c (ctf_archive_member): Print CTF errors and warnings. * readelf.c (dump_ctf_archive_member): Likewise.
2020-06-04 22:07:54 +08:00
/* Error-warning reporting: an 'iterator' that returns errors and warnings from
the error/warning list, in order of emission. Errors and warnings are popped
after return: the caller must free the returned error-text pointer. */
extern char *ctf_errwarning_next (ctf_file_t *, ctf_next_t **,
libctf, binutils, include, ld: gettextize and improve error handling This commit follows on from the earlier commit "libctf, ld, binutils: add textual error/warning reporting for libctf" and converts every error in libctf that was reported using ctf_dprintf to use ctf_err_warn instead, gettextizing them in the process, using N_() where necessary to avoid doing gettext calls unless an error message is actually generated, and rephrasing some error messages for ease of translation. This requires a slight change in the ctf_errwarning_next API: this API is public but has not been in a release yet, so can still change freely. The problem is that many errors are emitted at open time (whether opening of a CTF dict, or opening of a CTF archive): the former of these throws away its incompletely-initialized ctf_file_t rather than return it, and the latter has no ctf_file_t at all. So errors and warnings emitted at open time cannot be stored in the ctf_file_t, and have to go elsewhere. We put them in a static local in ctf-subr.c (which is not very thread-safe: a later commit will improve things here): ctf_err_warn with a NULL fp adds to this list, and the public interface ctf_errwarning_next with a NULL fp retrieves from it. We need a slight exception from the usual iterator rules in this case: with a NULL fp, there is nowhere to store the ECTF_NEXT_END "error" which signifies the end of iteration, so we add a new err parameter to ctf_errwarning_next which is used to report such iteration-related errors. (If an fp is provided -- i.e., if not reporting open errors -- this is optional, but even if it's optional it's still an API change. This is actually useful from a usability POV as well, since ctf_errwarning_next is usually called when there's been an error, so overwriting the error code with ECTF_NEXT_END is not very helpful! So, unusually, ctf_errwarning_next now uses the passed fp for its error code *only* if no errp pointer is passed in, and leaves it untouched otherwise.) ld, objdump and readelf are adapted to call ctf_errwarning_next with a NULL fp to report open errors where appropriate. The ctf_err_warn API also has to change, gaining a new error-number parameter which is used to add the error message corresponding to that error number into the debug stream when LIBCTF_DEBUG is enabled: changing this API is easy at this point since we are already touching all existing calls to gettextize them. We need this because the debug stream should contain the errno's message, but the error reported in the error/warning stream should *not*, because the caller will probably report it themselves at failure time regardless, and reporting it in every error message that leads up to it leads to a ridiculous chattering on failure, which is likely to end up as ridiculous chattering on stderr (trimmed a bit): CTF error: `ld/testsuite/ld-ctf/A.c (0): lookup failure for type 3: flags 1: The parent CTF dictionary is unavailable' CTF error: `ld/testsuite/ld-ctf/A.c (0): struct/union member type hashing error during type hashing for type 80000001, kind 6: The parent CTF dictionary is unavailable' CTF error: `deduplicating link variable emission failed for ld/testsuite/ld-ctf/A.c: The parent CTF dictionary is unavailable' ld/.libs/lt-ld-new: warning: CTF linking failed; output will have no CTF section: `The parent CTF dictionary is unavailable' We only need to be told that the parent CTF dictionary is unavailable *once*, not over and over again! errmsgs are still emitted on warning generation, because warnings do not usually lead to a failure propagated up to the caller and reported there. Debug-stream messages are not translated. If translation is turned on, there will be a mixture of English and translated messages in the debug stream, but rather that than burden the translators with debug-only output. binutils/ChangeLog 2020-08-27 Nick Alcock <nick.alcock@oracle.com> * objdump.c (dump_ctf_archive_member): Move error- reporting... (dump_ctf_errs): ... into this separate function. (dump_ctf): Call it on open errors. * readelf.c (dump_ctf_archive_member): Move error- reporting... (dump_ctf_errs): ... into this separate function. Support calls with NULL fp. Adjust for new err parameter to ctf_errwarning_next. (dump_section_as_ctf): Call it on open errors. include/ChangeLog 2020-08-27 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ctf_errwarning_next): New err parameter. ld/ChangeLog 2020-08-27 Nick Alcock <nick.alcock@oracle.com> * ldlang.c (lang_ctf_errs_warnings): Support calls with NULL fp. Adjust for new err parameter to ctf_errwarning_next. Only check for assertion failures when fp is non-NULL. (ldlang_open_ctf): Call it on open errors. * testsuite/ld-ctf/ctf.exp: Always use the C locale to avoid breaking the diags tests. libctf/ChangeLog 2020-08-27 Nick Alcock <nick.alcock@oracle.com> * ctf-subr.c (open_errors): New list. (ctf_err_warn): Calls with NULL fp append to open_errors. Add err parameter, and use it to decorate the debug stream with errmsgs. (ctf_err_warn_to_open): Splice errors from a CTF dict into the open_errors. (ctf_errwarning_next): Calls with NULL fp report from open_errors. New err param to report iteration errors (including end-of-iteration) when fp is NULL. (ctf_assert_fail_internal): Adjust ctf_err_warn call for new err parameter: gettextize. * ctf-impl.h (ctfo_get_vbytes): Add ctf_file_t parameter. (LCTF_VBYTES): Adjust. (ctf_err_warn_to_open): New. (ctf_err_warn): Adjust. (ctf_bundle): Used in only one place: move... * ctf-create.c: ... here. (enumcmp): Use ctf_err_warn, not ctf_dprintf, passing the err number down as needed. Don't emit the errmsg. Gettextize. (membcmp): Likewise. (ctf_add_type_internal): Likewise. (ctf_write_mem): Likewise. (ctf_compress_write): Likewise. Report errors writing the header or body. (ctf_write): Likewise. * ctf-archive.c (ctf_arc_write_fd): Use ctf_err_warn, not ctf_dprintf, and gettextize, as above. (ctf_arc_write): Likewise. (ctf_arc_bufopen): Likewise. (ctf_arc_open_internal): Likewise. * ctf-labels.c (ctf_label_iter): Likewise. * ctf-open-bfd.c (ctf_bfdclose): Likewise. (ctf_bfdopen): Likewise. (ctf_bfdopen_ctfsect): Likewise. (ctf_fdopen): Likewise. * ctf-string.c (ctf_str_write_strtab): Likewise. * ctf-types.c (ctf_type_resolve): Likewise. * ctf-open.c (get_vbytes_common): Likewise. Pass down the ctf dict. (get_vbytes_v1): Pass down the ctf dict. (get_vbytes_v2): Likewise. (flip_ctf): Likewise. (flip_types): Likewise. Use ctf_err_warn, not ctf_dprintf, and gettextize, as above. (upgrade_types_v1): Adjust calls. (init_types): Use ctf_err_warn, not ctf_dprintf, as above. (ctf_bufopen_internal): Likewise. Adjust calls. Transplant errors emitted into individual dicts into the open errors if this turns out to be a failed open in the end. * ctf-dump.c (ctf_dump_format_type): Adjust ctf_err_warn for new err argument. Gettextize. Don't emit the errmsg. (ctf_dump_funcs): Likewise. Collapse err label into its only case. (ctf_dump_type): Likewise. * ctf-link.c (ctf_create_per_cu): Adjust ctf_err_warn for new err argument. Gettextize. Don't emit the errmsg. (ctf_link_one_type): Likewise. (ctf_link_lazy_open): Likewise. (ctf_link_one_input_archive): Likewise. (ctf_link_deduplicating_count_inputs): Likewise. (ctf_link_deduplicating_open_inputs): Likewise. (ctf_link_deduplicating_close_inputs): Likewise. (ctf_link_deduplicating): Likewise. (ctf_link): Likewise. (ctf_link_deduplicating_per_cu): Likewise. Add some missed ctf_set_errnos to obscure error cases. * ctf-dedup.c (ctf_dedup_rhash_type): Adjust ctf_err_warn for new err argument. Gettextize. Don't emit the errmsg. (ctf_dedup_populate_mappings): Likewise. (ctf_dedup_detect_name_ambiguity): Likewise. (ctf_dedup_init): Likewise. (ctf_dedup_multiple_input_dicts): Likewise. (ctf_dedup_conflictify_unshared): Likewise. (ctf_dedup): Likewise. (ctf_dedup_rwalk_one_output_mapping): Likewise. (ctf_dedup_id_to_target): Likewise. (ctf_dedup_emit_type): Likewise. (ctf_dedup_emit_struct_members): Likewise. (ctf_dedup_populate_type_mapping): Likewise. (ctf_dedup_populate_type_mappings): Likewise. (ctf_dedup_emit): Likewise. (ctf_dedup_hash_type): Likewise. Fix a bit of messed-up error status setting. (ctf_dedup_rwalk_one_output_mapping): Likewise. Don't hide unknown-type-kind messages (which signify file corruption).
2020-07-27 23:45:15 +08:00
int *is_warning, int *errp);
libctf, ld, binutils: add textual error/warning reporting for libctf This commit adds a long-missing piece of infrastructure to libctf: the ability to report errors and warnings using all the power of printf, rather than being restricted to one errno value. Internally, libctf calls ctf_err_warn() to add errors and warnings to a list: a new iterator ctf_errwarning_next() then consumes this list one by one and hands it to the caller, which can free it. New errors and warnings are added until the list is consumed by the caller or the ctf_file_t is closed, so you can dump them at intervals. The caller can of course choose to print only those warnings it wants. (I am not sure whether we want objdump, readelf or ld to print warnings or not: right now I'm printing them, but maybe we only want to print errors? This entirely depends on whether warnings are voluminous things describing e.g. the inability to emit single types because of name clashes or something. There are no users of this infrastructure yet, so it's hard to say.) There is no internationalization here yet, but this at least adds a place where internationalization can be added, to one of ctf_errwarning_next or ctf_err_warn. We also provide a new ctf_assert() function which uses this infrastructure to provide non-fatal assertion failures while emitting an assert-like string to the caller: to save space and avoid needlessly duplicating unchanging strings, the assertion test is inlined but the print-things-out failure case is not. All assertions in libctf will be converted to use this machinery in future commits and propagate assertion-failure errors up, so that the linker in particular cannot be killed by libctf assertion failures when it could perfectly well just print warnings and drop the CTF section. include/ * ctf-api.h (ECTF_INTERNAL): Adjust error text. (ctf_errwarning_next): New. libctf/ * ctf-impl.h (ctf_assert): New. (ctf_err_warning_t): Likewise. (ctf_file_t) <ctf_errs_warnings>: Likewise. (ctf_err_warn): New prototype. (ctf_assert_fail_internal): Likewise. * ctf-inlines.h (ctf_assert_internal): Likewise. * ctf-open.c (ctf_file_close): Free ctf_errs_warnings. * ctf-create.c (ctf_serialize): Copy it on serialization. * ctf-subr.c (ctf_err_warn): New, add an error/warning. (ctf_errwarning_next): New iterator, free and pass back errors/warnings in succession. * libctf.ver (ctf_errwarning_next): Add. ld/ * ldlang.c (lang_ctf_errs_warnings): New, print CTF errors and warnings. Assert when libctf asserts. (lang_merge_ctf): Call it. (land_write_ctf): Likewise. binutils/ * objdump.c (ctf_archive_member): Print CTF errors and warnings. * readelf.c (dump_ctf_archive_member): Likewise.
2020-06-04 22:07:54 +08:00
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
2019-04-24 05:45:46 +08:00
extern ctf_id_t ctf_add_array (ctf_file_t *, uint32_t,
const ctf_arinfo_t *);
extern ctf_id_t ctf_add_const (ctf_file_t *, uint32_t, ctf_id_t);
extern ctf_id_t ctf_add_enum_encoded (ctf_file_t *, uint32_t, const char *,
const ctf_encoding_t *);
extern ctf_id_t ctf_add_enum (ctf_file_t *, uint32_t, const char *);
extern ctf_id_t ctf_add_float (ctf_file_t *, uint32_t,
const char *, const ctf_encoding_t *);
extern ctf_id_t ctf_add_forward (ctf_file_t *, uint32_t, const char *,
uint32_t);
extern ctf_id_t ctf_add_function (ctf_file_t *, uint32_t,
const ctf_funcinfo_t *, const ctf_id_t *);
extern ctf_id_t ctf_add_integer (ctf_file_t *, uint32_t, const char *,
const ctf_encoding_t *);
extern ctf_id_t ctf_add_slice (ctf_file_t *, uint32_t, ctf_id_t, const ctf_encoding_t *);
extern ctf_id_t ctf_add_pointer (ctf_file_t *, uint32_t, ctf_id_t);
extern ctf_id_t ctf_add_type (ctf_file_t *, ctf_file_t *, ctf_id_t);
extern ctf_id_t ctf_add_typedef (ctf_file_t *, uint32_t, const char *,
ctf_id_t);
extern ctf_id_t ctf_add_restrict (ctf_file_t *, uint32_t, ctf_id_t);
extern ctf_id_t ctf_add_struct (ctf_file_t *, uint32_t, const char *);
extern ctf_id_t ctf_add_union (ctf_file_t *, uint32_t, const char *);
extern ctf_id_t ctf_add_struct_sized (ctf_file_t *, uint32_t, const char *,
size_t);
extern ctf_id_t ctf_add_union_sized (ctf_file_t *, uint32_t, const char *,
size_t);
extern ctf_id_t ctf_add_volatile (ctf_file_t *, uint32_t, ctf_id_t);
extern int ctf_add_enumerator (ctf_file_t *, ctf_id_t, const char *, int);
extern int ctf_add_member (ctf_file_t *, ctf_id_t, const char *, ctf_id_t);
extern int ctf_add_member_offset (ctf_file_t *, ctf_id_t, const char *,
ctf_id_t, unsigned long);
extern int ctf_add_member_encoded (ctf_file_t *, ctf_id_t, const char *,
ctf_id_t, unsigned long,
const ctf_encoding_t);
extern int ctf_add_variable (ctf_file_t *, const char *, ctf_id_t);
extern int ctf_set_array (ctf_file_t *, ctf_id_t, const ctf_arinfo_t *);
extern ctf_file_t *ctf_create (int *);
extern int ctf_update (ctf_file_t *);
extern ctf_snapshot_id_t ctf_snapshot (ctf_file_t *);
extern int ctf_rollback (ctf_file_t *, ctf_snapshot_id_t);
extern int ctf_discard (ctf_file_t *);
extern int ctf_write (ctf_file_t *, int);
extern int ctf_gzwrite (ctf_file_t *fp, gzFile fd);
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
2019-04-24 05:45:46 +08:00
extern int ctf_compress_write (ctf_file_t * fp, int fd);
extern unsigned char *ctf_write_mem (ctf_file_t *, size_t *, size_t threshold);
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
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extern int ctf_link_add_ctf (ctf_file_t *, ctf_archive_t *, const char *);
/* The variable filter should return nonzero if a variable should not
appear in the output. */
typedef int ctf_link_variable_filter_f (ctf_file_t *, const char *, ctf_id_t,
void *);
extern int ctf_link_set_variable_filter (ctf_file_t *,
ctf_link_variable_filter_f *, void *);
libctf, link: add lazy linking: clean up input members: err/warn cleanup This rather large and intertwined pile of changes does three things: First, it transitions from dprintf to ctf_err_warn for things the user might care about: this one file is the major impetus for the ctf_err_warn infrastructure, because things like file names are crucial in linker error messages, and errno values are utterly incapable of communicating them Second, it stabilizes the ctf_link APIs: you can now call ctf_link_add_ctf without a CTF argument (only a NAME), to lazily ctf_open the file with the given NAME when needed, and close it as soon as possible, to save memory. This is not an API change because a null CTF argument was prohibited before now. Since getting CTF directly from files uses ctf_open, passing in only a NAME requires use of libctf, not libctf-nobfd. The linker's behaviour is unchanged, as it still passes in a ctf_archive_t as before. This also let us fix a leak: we were opening ctf_archives and their containing ctf_files, then only closing the files and leaving the archives open. Third, this commit restructures the ctf_link_in_member argument used by the CTF linking machinery and adjusts its users accordingly. We drop two members: - arcname, which is difficult to construct and then only used in error messages (that were only dprintf()ed, so never seen!) - share_mode, since we store the flags passed to ctf_link (including the share mode) in a new ctf_file_t.ctf_link_flags to help dedup get hold of it We rename others whose existing names were fairly dreadful: - done_main_member -> done_parent, using consistent terminology for .ctf as the parent of all archive members - main_input_fp -> in_fp_parent, likewise - file_name -> in_file_name, likewise We add one new member, cu_mapped. Finally, we move the various frees of things like mapping table data to the top-level ctf_link, since deduplicating links will want to do that too. include/ * ctf-api.h (ECTF_NEEDSBFD): New. (ECTF_NERR): Adjust. (ctf_link): Rename share_mode arg to flags. libctf/ * Makefile.am: Set -DNOBFD=1 in libctf-nobfd, and =0 elsewhere. * Makefile.in: Regenerated. * ctf-impl.h (ctf_link_input_name): New. (ctf_file_t) <ctf_link_flags>: New. * ctf-create.c (ctf_serialize): Adjust accordingly. * ctf-link.c: Define ctf_open as weak when PIC. (ctf_arc_close_thunk): Remove unnecessary thunk. (ctf_file_close_thunk): Likewise. (ctf_link_input_name): New. (ctf_link_input_t): New value of the ctf_file_t.ctf_link_input. (ctf_link_input_close): Adjust accordingly. (ctf_link_add_ctf_internal): New, split from... (ctf_link_add_ctf): ... here. Return error if lazy loading of CTF is not possible. Change to just call... (ctf_link_add): ... this new function. (ctf_link_add_cu_mapping): Transition to ctf_err_warn. Drop the ctf_file_close_thunk. (ctf_link_in_member_cb_arg_t) <file_name> Rename to... <in_file_name>: ... this. <arcname>: Drop. <share_mode>: Likewise (migrated to ctf_link_flags). <done_main_member>: Rename to... <done_parent>: ... this. <main_input_fp>: Rename to... <in_fp_parent>: ... this. <cu_mapped>: New. (ctf_link_one_type): Adjuwt accordingly. Transition to ctf_err_warn, removing a TODO. (ctf_link_one_variable): Note a case too common to warn about. Report in the debug stream if a cu-mapped link prevents addition of a conflicting variable. (ctf_link_one_input_archive_member): Adjust. (ctf_link_lazy_open): New, open a CTF archive for linking when needed. (ctf_link_close_one_input_archive): New, close it again. (ctf_link_one_input_archive): Adjust for lazy opening, member renames, and ctf_err_warn transition. Move the empty_link_type_mapping call to... (ctf_link): ... here. Adjut for renamings and thunk removal. Don't spuriously fail if some input contains no CTF data. (ctf_link_write): ctf_err_warn transition. * libctf.ver: Remove not-yet-stable comment.
2020-06-05 02:28:52 +08:00
extern int ctf_link (ctf_file_t *, int flags);
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
2019-07-14 04:06:55 +08:00
typedef const char *ctf_link_strtab_string_f (uint32_t *offset, void *arg);
extern int ctf_link_add_strtab (ctf_file_t *, ctf_link_strtab_string_f *,
void *);
typedef ctf_link_sym_t *ctf_link_iter_symbol_f (ctf_link_sym_t *dest,
void *arg);
extern int ctf_link_shuffle_syms (ctf_file_t *, ctf_link_iter_symbol_f *,
void *);
extern unsigned char *ctf_link_write (ctf_file_t *, size_t *size,
size_t threshold);
libctf: add CU-mapping machinery Once the deduplicator is capable of actually detecting conflicting types with the same name (i.e., not yet) we will place such conflicting types, and types that depend on them, into CTF dictionaries that are the child of the main dictionary we usually emit: currently, this will lead to the .ctf section becoming a CTF archive rather than a single dictionary, with the default-named archive member (_CTF_SECTION, or NULL) being the main shared dictionary with most of the types in it. By default, the sections are named after the compilation unit they come from (complete path and all), with the cuname field in the CTF header providing further evidence of the name without requiring the caller to engage in tiresome parsing. But some callers may not wish the mapping from input CU to output sub-dictionary to be purely CU-based. The machinery here allows this to be freely changed, in two ways: - callers can call ctf_link_add_cu_mapping to specify that a single input compilation unit should have its types placed in some other CU if they conflict: the CU will always be created, even if empty, so the consuming program can depend on its existence. You can map multiple input CUs to one output CU to force all their types to be merged together: if some of *those* types conflict, the behaviour is currently unspecified (the new deduplicator will specify it). - callers can call ctf_link_set_memb_name_changer to provide a function which is passed every CTF sub-dictionary name in turn (including _CTF_SECTION) and can return a new name, or NULL if no change is desired. The mapping from input to output names should not map two input names to the same output name: if this happens, the two are not merged but will result in an archive with two members with the same name (technically valid, but it's hard to access the second same-named member: you have to do an iteration over archive members). This is used by the kernel's ctfarchive machinery (not yet upstream) to encode CTF under member names like {module name}.ctf rather than .ctf.CU, but it is anticipated that other large projects may wish to have their own storage for CTF outside of .ctf sections and may wish to have new naming schemes that suit their special-purpose consumers. New in v3. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (ctf_link_add_cu_mapping): New. (ctf_link_memb_name_changer_f): New. (ctf_link_set_memb_name_changer): New. libctf/ * ctf-impl.h (ctf_file_t) <ctf_link_cu_mappping>: New. <ctf_link_memb_name_changer>: Likewise. <ctf_link_memb_name_changer_arg>: Likewise. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-link.c (ctf_create_per_cu): Apply the cu mapping. (ctf_link_add_cu_mapping): New. (ctf_link_set_memb_name_changer): Likewise. (ctf_change_parent_name): New. (ctf_name_list_accum_cb_arg_t) <dynames>: New, storage for names allocated by the caller's ctf_link_memb_name_changer. <ndynames>: Likewise. (ctf_accumulate_archive_names): Call the ctf_link_memb_name_changer. (ctf_link_write): Likewise (for _CTF_SECTION only): also call ctf_change_parent_name. Free any resulting names.
2019-07-20 21:44:44 +08:00
/* Specialist linker functions. These functions are not used by ld, but can be
used by other programs making use of the linker machinery for other purposes
libctf: add CU-mapping machinery Once the deduplicator is capable of actually detecting conflicting types with the same name (i.e., not yet) we will place such conflicting types, and types that depend on them, into CTF dictionaries that are the child of the main dictionary we usually emit: currently, this will lead to the .ctf section becoming a CTF archive rather than a single dictionary, with the default-named archive member (_CTF_SECTION, or NULL) being the main shared dictionary with most of the types in it. By default, the sections are named after the compilation unit they come from (complete path and all), with the cuname field in the CTF header providing further evidence of the name without requiring the caller to engage in tiresome parsing. But some callers may not wish the mapping from input CU to output sub-dictionary to be purely CU-based. The machinery here allows this to be freely changed, in two ways: - callers can call ctf_link_add_cu_mapping to specify that a single input compilation unit should have its types placed in some other CU if they conflict: the CU will always be created, even if empty, so the consuming program can depend on its existence. You can map multiple input CUs to one output CU to force all their types to be merged together: if some of *those* types conflict, the behaviour is currently unspecified (the new deduplicator will specify it). - callers can call ctf_link_set_memb_name_changer to provide a function which is passed every CTF sub-dictionary name in turn (including _CTF_SECTION) and can return a new name, or NULL if no change is desired. The mapping from input to output names should not map two input names to the same output name: if this happens, the two are not merged but will result in an archive with two members with the same name (technically valid, but it's hard to access the second same-named member: you have to do an iteration over archive members). This is used by the kernel's ctfarchive machinery (not yet upstream) to encode CTF under member names like {module name}.ctf rather than .ctf.CU, but it is anticipated that other large projects may wish to have their own storage for CTF outside of .ctf sections and may wish to have new naming schemes that suit their special-purpose consumers. New in v3. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (ctf_link_add_cu_mapping): New. (ctf_link_memb_name_changer_f): New. (ctf_link_set_memb_name_changer): New. libctf/ * ctf-impl.h (ctf_file_t) <ctf_link_cu_mappping>: New. <ctf_link_memb_name_changer>: Likewise. <ctf_link_memb_name_changer_arg>: Likewise. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-link.c (ctf_create_per_cu): Apply the cu mapping. (ctf_link_add_cu_mapping): New. (ctf_link_set_memb_name_changer): Likewise. (ctf_change_parent_name): New. (ctf_name_list_accum_cb_arg_t) <dynames>: New, storage for names allocated by the caller's ctf_link_memb_name_changer. <ndynames>: Likewise. (ctf_accumulate_archive_names): Call the ctf_link_memb_name_changer. (ctf_link_write): Likewise (for _CTF_SECTION only): also call ctf_change_parent_name. Free any resulting names.
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to customize its output. */
extern int ctf_link_add_cu_mapping (ctf_file_t *, const char *from,
const char *to);
typedef char *ctf_link_memb_name_changer_f (ctf_file_t *,
const char *, void *);
extern void ctf_link_set_memb_name_changer
(ctf_file_t *, ctf_link_memb_name_changer_f *, void *);
extern void ctf_setdebug (int debug);
extern int ctf_getdebug (void);
#ifdef __cplusplus
}
#endif
#endif /* _CTF_API_H */