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binutils-gdb/bfd/syms.c
Ian Lance Taylor f104a86e1b update copyright
1996-01-29 22:09:49 +00:00

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/* Generic symbol-table support for the BFD library.
Copyright (C) 1990, 91, 92, 93, 94, 95, 1996 Free Software Foundation, Inc.
Written by Cygnus Support.
This file is part of BFD, the Binary File Descriptor library.
This program 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 2 of the License, 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; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/*
SECTION
Symbols
BFD tries to maintain as much symbol information as it can when
it moves information from file to file. BFD passes information
to applications though the <<asymbol>> structure. When the
application requests the symbol table, BFD reads the table in
the native form and translates parts of it into the internal
format. To maintain more than the information passed to
applications, some targets keep some information ``behind the
scenes'' in a structure only the particular back end knows
about. For example, the coff back end keeps the original
symbol table structure as well as the canonical structure when
a BFD is read in. On output, the coff back end can reconstruct
the output symbol table so that no information is lost, even
information unique to coff which BFD doesn't know or
understand. If a coff symbol table were read, but were written
through an a.out back end, all the coff specific information
would be lost. The symbol table of a BFD
is not necessarily read in until a canonicalize request is
made. Then the BFD back end fills in a table provided by the
application with pointers to the canonical information. To
output symbols, the application provides BFD with a table of
pointers to pointers to <<asymbol>>s. This allows applications
like the linker to output a symbol as it was read, since the ``behind
the scenes'' information will be still available.
@menu
@* Reading Symbols::
@* Writing Symbols::
@* Mini Symbols::
@* typedef asymbol::
@* symbol handling functions::
@end menu
INODE
Reading Symbols, Writing Symbols, Symbols, Symbols
SUBSECTION
Reading symbols
There are two stages to reading a symbol table from a BFD:
allocating storage, and the actual reading process. This is an
excerpt from an application which reads the symbol table:
| long storage_needed;
| asymbol **symbol_table;
| long number_of_symbols;
| long i;
|
| storage_needed = bfd_get_symtab_upper_bound (abfd);
|
| if (storage_needed < 0)
| FAIL
|
| if (storage_needed == 0) {
| return ;
| }
| symbol_table = (asymbol **) xmalloc (storage_needed);
| ...
| number_of_symbols =
| bfd_canonicalize_symtab (abfd, symbol_table);
|
| if (number_of_symbols < 0)
| FAIL
|
| for (i = 0; i < number_of_symbols; i++) {
| process_symbol (symbol_table[i]);
| }
All storage for the symbols themselves is in an obstack
connected to the BFD; it is freed when the BFD is closed.
INODE
Writing Symbols, Mini Symbols, Reading Symbols, Symbols
SUBSECTION
Writing symbols
Writing of a symbol table is automatic when a BFD open for
writing is closed. The application attaches a vector of
pointers to pointers to symbols to the BFD being written, and
fills in the symbol count. The close and cleanup code reads
through the table provided and performs all the necessary
operations. The BFD output code must always be provided with an
``owned'' symbol: one which has come from another BFD, or one
which has been created using <<bfd_make_empty_symbol>>. Here is an
example showing the creation of a symbol table with only one element:
| #include "bfd.h"
| main()
| {
| bfd *abfd;
| asymbol *ptrs[2];
| asymbol *new;
|
| abfd = bfd_openw("foo","a.out-sunos-big");
| bfd_set_format(abfd, bfd_object);
| new = bfd_make_empty_symbol(abfd);
| new->name = "dummy_symbol";
| new->section = bfd_make_section_old_way(abfd, ".text");
| new->flags = BSF_GLOBAL;
| new->value = 0x12345;
|
| ptrs[0] = new;
| ptrs[1] = (asymbol *)0;
|
| bfd_set_symtab(abfd, ptrs, 1);
| bfd_close(abfd);
| }
|
| ./makesym
| nm foo
| 00012345 A dummy_symbol
Many formats cannot represent arbitary symbol information; for
instance, the <<a.out>> object format does not allow an
arbitary number of sections. A symbol pointing to a section
which is not one of <<.text>>, <<.data>> or <<.bss>> cannot
be described.
INODE
Mini Symbols, typedef asymbol, Writing Symbols, Symbols
SUBSECTION
Mini Symbols
Mini symbols provide read-only access to the symbol table.
They use less memory space, but require more time to access.
They can be useful for tools like nm or objdump, which may
have to handle symbol tables of extremely large executables.
The <<bfd_read_minisymbols>> function will read the symbols
into memory in an internal form. It will return a <<void *>>
pointer to a block of memory, a symbol count, and the size of
each symbol. The pointer is allocated using <<malloc>>, and
should be freed by the caller when it is no longer needed.
The function <<bfd_minisymbol_to_symbol>> will take a pointer
to a minisymbol, and a pointer to a structure returned by
<<bfd_make_empty_symbol>>, and return a <<asymbol>> structure.
The return value may or may not be the same as the value from
<<bfd_make_empty_symbol>> which was passed in.
*/
/*
DOCDD
INODE
typedef asymbol, symbol handling functions, Mini Symbols, Symbols
*/
/*
SUBSECTION
typedef asymbol
An <<asymbol>> has the form:
*/
/*
CODE_FRAGMENT
.
.typedef struct symbol_cache_entry
.{
. {* A pointer to the BFD which owns the symbol. This information
. is necessary so that a back end can work out what additional
. information (invisible to the application writer) is carried
. with the symbol.
.
. This field is *almost* redundant, since you can use section->owner
. instead, except that some symbols point to the global sections
. bfd_{abs,com,und}_section. This could be fixed by making
. these globals be per-bfd (or per-target-flavor). FIXME. *}
.
. struct _bfd *the_bfd; {* Use bfd_asymbol_bfd(sym) to access this field. *}
.
. {* The text of the symbol. The name is left alone, and not copied; the
. application may not alter it. *}
. CONST char *name;
.
. {* The value of the symbol. This really should be a union of a
. numeric value with a pointer, since some flags indicate that
. a pointer to another symbol is stored here. *}
. symvalue value;
.
. {* Attributes of a symbol: *}
.
.#define BSF_NO_FLAGS 0x00
.
. {* The symbol has local scope; <<static>> in <<C>>. The value
. is the offset into the section of the data. *}
.#define BSF_LOCAL 0x01
.
. {* The symbol has global scope; initialized data in <<C>>. The
. value is the offset into the section of the data. *}
.#define BSF_GLOBAL 0x02
.
. {* The symbol has global scope and is exported. The value is
. the offset into the section of the data. *}
.#define BSF_EXPORT BSF_GLOBAL {* no real difference *}
.
. {* A normal C symbol would be one of:
. <<BSF_LOCAL>>, <<BSF_FORT_COMM>>, <<BSF_UNDEFINED>> or
. <<BSF_GLOBAL>> *}
.
. {* The symbol is a debugging record. The value has an arbitary
. meaning. *}
.#define BSF_DEBUGGING 0x08
.
. {* The symbol denotes a function entry point. Used in ELF,
. perhaps others someday. *}
.#define BSF_FUNCTION 0x10
.
. {* Used by the linker. *}
.#define BSF_KEEP 0x20
.#define BSF_KEEP_G 0x40
.
. {* A weak global symbol, overridable without warnings by
. a regular global symbol of the same name. *}
.#define BSF_WEAK 0x80
.
. {* This symbol was created to point to a section, e.g. ELF's
. STT_SECTION symbols. *}
.#define BSF_SECTION_SYM 0x100
.
. {* The symbol used to be a common symbol, but now it is
. allocated. *}
.#define BSF_OLD_COMMON 0x200
.
. {* The default value for common data. *}
.#define BFD_FORT_COMM_DEFAULT_VALUE 0
.
. {* In some files the type of a symbol sometimes alters its
. location in an output file - ie in coff a <<ISFCN>> symbol
. which is also <<C_EXT>> symbol appears where it was
. declared and not at the end of a section. This bit is set
. by the target BFD part to convey this information. *}
.
.#define BSF_NOT_AT_END 0x400
.
. {* Signal that the symbol is the label of constructor section. *}
.#define BSF_CONSTRUCTOR 0x800
.
. {* Signal that the symbol is a warning symbol. The name is a
. warning. The name of the next symbol is the one to warn about;
. if a reference is made to a symbol with the same name as the next
. symbol, a warning is issued by the linker. *}
.#define BSF_WARNING 0x1000
.
. {* Signal that the symbol is indirect. This symbol is an indirect
. pointer to the symbol with the same name as the next symbol. *}
.#define BSF_INDIRECT 0x2000
.
. {* BSF_FILE marks symbols that contain a file name. This is used
. for ELF STT_FILE symbols. *}
.#define BSF_FILE 0x4000
.
. {* Symbol is from dynamic linking information. *}
.#define BSF_DYNAMIC 0x8000
.
. {* The symbol denotes a data object. Used in ELF, and perhaps
. others someday. *}
.#define BSF_OBJECT 0x10000
.
. flagword flags;
.
. {* A pointer to the section to which this symbol is
. relative. This will always be non NULL, there are special
. sections for undefined and absolute symbols. *}
. struct sec *section;
.
. {* Back end special data. *}
. union
. {
. PTR p;
. bfd_vma i;
. } udata;
.
.} asymbol;
*/
#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "bfdlink.h"
#include "aout/stab_gnu.h"
/*
DOCDD
INODE
symbol handling functions, , typedef asymbol, Symbols
SUBSECTION
Symbol handling functions
*/
/*
FUNCTION
bfd_get_symtab_upper_bound
DESCRIPTION
Return the number of bytes required to store a vector of pointers
to <<asymbols>> for all the symbols in the BFD @var{abfd},
including a terminal NULL pointer. If there are no symbols in
the BFD, then return 0. If an error occurs, return -1.
.#define bfd_get_symtab_upper_bound(abfd) \
. BFD_SEND (abfd, _bfd_get_symtab_upper_bound, (abfd))
*/
/*
FUNCTION
bfd_is_local_label
SYNOPSIS
boolean bfd_is_local_label(bfd *abfd, asymbol *sym);
DESCRIPTION
Return true if the given symbol @var{sym} in the BFD @var{abfd} is
a compiler generated local label, else return false.
.#define bfd_is_local_label(abfd, sym) \
. BFD_SEND (abfd, _bfd_is_local_label,(abfd, sym))
*/
/*
FUNCTION
bfd_canonicalize_symtab
DESCRIPTION
Read the symbols from the BFD @var{abfd}, and fills in
the vector @var{location} with pointers to the symbols and
a trailing NULL.
Return the actual number of symbol pointers, not
including the NULL.
.#define bfd_canonicalize_symtab(abfd, location) \
. BFD_SEND (abfd, _bfd_canonicalize_symtab,\
. (abfd, location))
*/
/*
FUNCTION
bfd_set_symtab
SYNOPSIS
boolean bfd_set_symtab (bfd *abfd, asymbol **location, unsigned int count);
DESCRIPTION
Arrange that when the output BFD @var{abfd} is closed,
the table @var{location} of @var{count} pointers to symbols
will be written.
*/
boolean
bfd_set_symtab (abfd, location, symcount)
bfd *abfd;
asymbol **location;
unsigned int symcount;
{
if ((abfd->format != bfd_object) || (bfd_read_p (abfd)))
{
bfd_set_error (bfd_error_invalid_operation);
return false;
}
bfd_get_outsymbols (abfd) = location;
bfd_get_symcount (abfd) = symcount;
return true;
}
/*
FUNCTION
bfd_print_symbol_vandf
SYNOPSIS
void bfd_print_symbol_vandf(PTR file, asymbol *symbol);
DESCRIPTION
Print the value and flags of the @var{symbol} supplied to the
stream @var{file}.
*/
void
bfd_print_symbol_vandf (arg, symbol)
PTR arg;
asymbol *symbol;
{
FILE *file = (FILE *) arg;
flagword type = symbol->flags;
if (symbol->section != (asection *) NULL)
{
fprintf_vma (file, symbol->value + symbol->section->vma);
}
else
{
fprintf_vma (file, symbol->value);
}
/* This presumes that a symbol can not be both BSF_DEBUGGING and
BSF_DYNAMIC, nor more than one of BSF_FUNCTION, BSF_FILE, and
BSF_OBJECT. */
fprintf (file, " %c%c%c%c%c%c%c",
((type & BSF_LOCAL)
? (type & BSF_GLOBAL) ? '!' : 'l'
: (type & BSF_GLOBAL) ? 'g' : ' '),
(type & BSF_WEAK) ? 'w' : ' ',
(type & BSF_CONSTRUCTOR) ? 'C' : ' ',
(type & BSF_WARNING) ? 'W' : ' ',
(type & BSF_INDIRECT) ? 'I' : ' ',
(type & BSF_DEBUGGING) ? 'd' : (type & BSF_DYNAMIC) ? 'D' : ' ',
((type & BSF_FUNCTION)
? 'F'
: ((type & BSF_FILE)
? 'f'
: ((type & BSF_OBJECT) ? 'O' : ' '))));
}
/*
FUNCTION
bfd_make_empty_symbol
DESCRIPTION
Create a new <<asymbol>> structure for the BFD @var{abfd}
and return a pointer to it.
This routine is necessary because each back end has private
information surrounding the <<asymbol>>. Building your own
<<asymbol>> and pointing to it will not create the private
information, and will cause problems later on.
.#define bfd_make_empty_symbol(abfd) \
. BFD_SEND (abfd, _bfd_make_empty_symbol, (abfd))
*/
/*
FUNCTION
bfd_make_debug_symbol
DESCRIPTION
Create a new <<asymbol>> structure for the BFD @var{abfd},
to be used as a debugging symbol. Further details of its use have
yet to be worked out.
.#define bfd_make_debug_symbol(abfd,ptr,size) \
. BFD_SEND (abfd, _bfd_make_debug_symbol, (abfd, ptr, size))
*/
struct section_to_type
{
CONST char *section;
char type;
};
/* Map section names to POSIX/BSD single-character symbol types.
This table is probably incomplete. It is sorted for convenience of
adding entries. Since it is so short, a linear search is used. */
static CONST struct section_to_type stt[] =
{
{"*DEBUG*", 'N'},
{".bss", 'b'},
{".data", 'd'},
{".rdata", 'r'}, /* Read only data. */
{".rodata", 'r'}, /* Read only data. */
{".sbss", 's'}, /* Small BSS (uninitialized data). */
{".scommon", 'c'}, /* Small common. */
{".sdata", 'g'}, /* Small initialized data. */
{".text", 't'},
{0, 0}
};
/* Return the single-character symbol type corresponding to
section S, or '?' for an unknown COFF section.
Check for any leading string which matches, so .text5 returns
't' as well as .text */
static char
coff_section_type (s)
char *s;
{
CONST struct section_to_type *t;
for (t = &stt[0]; t->section; t++)
if (!strncmp (s, t->section, strlen (t->section)))
return t->type;
return '?';
}
#ifndef islower
#define islower(c) ((c) >= 'a' && (c) <= 'z')
#endif
#ifndef toupper
#define toupper(c) (islower(c) ? ((c) & ~0x20) : (c))
#endif
/*
FUNCTION
bfd_decode_symclass
DESCRIPTION
Return a character corresponding to the symbol
class of @var{symbol}, or '?' for an unknown class.
SYNOPSIS
int bfd_decode_symclass(asymbol *symbol);
*/
int
bfd_decode_symclass (symbol)
asymbol *symbol;
{
char c;
if (bfd_is_com_section (symbol->section))
return 'C';
if (bfd_is_und_section (symbol->section))
return 'U';
if (bfd_is_ind_section (symbol->section))
return 'I';
if (symbol->flags & BSF_WEAK)
return 'W';
if (!(symbol->flags & (BSF_GLOBAL | BSF_LOCAL)))
return '?';
if (bfd_is_abs_section (symbol->section))
c = 'a';
else if (symbol->section)
c = coff_section_type (symbol->section->name);
else
return '?';
if (symbol->flags & BSF_GLOBAL)
c = toupper (c);
return c;
/* We don't have to handle these cases just yet, but we will soon:
N_SETV: 'v';
N_SETA: 'l';
N_SETT: 'x';
N_SETD: 'z';
N_SETB: 's';
N_INDR: 'i';
*/
}
/*
FUNCTION
bfd_symbol_info
DESCRIPTION
Fill in the basic info about symbol that nm needs.
Additional info may be added by the back-ends after
calling this function.
SYNOPSIS
void bfd_symbol_info(asymbol *symbol, symbol_info *ret);
*/
void
bfd_symbol_info (symbol, ret)
asymbol *symbol;
symbol_info *ret;
{
ret->type = bfd_decode_symclass (symbol);
if (ret->type != 'U')
ret->value = symbol->value + symbol->section->vma;
else
ret->value = 0;
ret->name = symbol->name;
}
void
bfd_symbol_is_absolute ()
{
abort ();
}
/*
FUNCTION
bfd_copy_private_symbol_data
SYNOPSIS
boolean bfd_copy_private_symbol_data(bfd *ibfd, asymbol *isym, bfd *obfd, asymbol *osym);
DESCRIPTION
Copy private symbol information from @var{isym} in the BFD
@var{ibfd} to the symbol @var{osym} in the BFD @var{obfd}.
Return <<true>> on success, <<false>> on error. Possible error
returns are:
o <<bfd_error_no_memory>> -
Not enough memory exists to create private data for @var{osec}.
.#define bfd_copy_private_symbol_data(ibfd, isymbol, obfd, osymbol) \
. BFD_SEND (ibfd, _bfd_copy_private_symbol_data, \
. (ibfd, isymbol, obfd, osymbol))
*/
/* The generic version of the function which returns mini symbols.
This is used when the backend does not provide a more efficient
version. It just uses BFD asymbol structures as mini symbols. */
long
_bfd_generic_read_minisymbols (abfd, dynamic, minisymsp, sizep)
bfd *abfd;
boolean dynamic;
PTR *minisymsp;
unsigned int *sizep;
{
long storage;
asymbol **syms = NULL;
long symcount;
if (dynamic)
storage = bfd_get_dynamic_symtab_upper_bound (abfd);
else
storage = bfd_get_symtab_upper_bound (abfd);
if (storage < 0)
goto error_return;
syms = (asymbol **) bfd_malloc ((size_t) storage);
if (syms == NULL)
goto error_return;
if (dynamic)
symcount = bfd_canonicalize_dynamic_symtab (abfd, syms);
else
symcount = bfd_canonicalize_symtab (abfd, syms);
if (symcount < 0)
goto error_return;
*minisymsp = (PTR) syms;
*sizep = sizeof (asymbol *);
return symcount;
error_return:
if (syms != NULL)
free (syms);
return -1;
}
/* The generic version of the function which converts a minisymbol to
an asymbol. We don't worry about the sym argument we are passed;
we just return the asymbol the minisymbol points to. */
/*ARGSUSED*/
asymbol *
_bfd_generic_minisymbol_to_symbol (abfd, dynamic, minisym, sym)
bfd *abfd;
boolean dynamic;
const PTR minisym;
asymbol *sym;
{
return *(asymbol **) minisym;
}
/* Look through stabs debugging information in .stab and .stabstr
sections to find the source file and line closest to a desired
location. This is used by COFF and ELF targets. It sets *pfound
to true if it finds some information. The *pinfo field is used to
pass cached information in and out of this routine; this first time
the routine is called for a BFD, *pinfo should be NULL. The value
placed in *pinfo should be saved with the BFD, and passed back each
time this function is called. */
/* A pointer to this structure is stored in *pinfo. */
struct stab_find_info
{
/* The .stab section. */
asection *stabsec;
/* The .stabstr section. */
asection *strsec;
/* The contents of the .stab section. */
bfd_byte *stabs;
/* The contents of the .stabstr section. */
bfd_byte *strs;
/* An malloc buffer to hold the file name. */
char *filename;
/* Cached values to restart quickly. */
bfd_vma cached_offset;
bfd_byte *cached_stab;
bfd_byte *cached_str;
bfd_size_type cached_stroff;
};
boolean
_bfd_stab_section_find_nearest_line (abfd, symbols, section, offset, pfound,
pfilename, pfnname, pline, pinfo)
bfd *abfd;
asymbol **symbols;
asection *section;
bfd_vma offset;
boolean *pfound;
const char **pfilename;
const char **pfnname;
unsigned int *pline;
PTR *pinfo;
{
struct stab_find_info *info;
bfd_size_type stabsize, strsize;
bfd_byte *stab, *stabend, *str;
bfd_size_type stroff;
bfd_vma fnaddr;
char *directory_name, *main_file_name, *current_file_name, *line_file_name;
char *fnname;
bfd_vma low_func_vma, low_line_vma;
*pfound = false;
*pfilename = bfd_get_filename (abfd);
*pfnname = NULL;
*pline = 0;
info = (struct stab_find_info *) *pinfo;
if (info != NULL)
{
if (info->stabsec == NULL || info->strsec == NULL)
{
/* No stabs debugging information. */
return true;
}
stabsize = info->stabsec->_raw_size;
strsize = info->strsec->_raw_size;
}
else
{
long reloc_size, reloc_count;
arelent **reloc_vector;
info = (struct stab_find_info *) bfd_zalloc (abfd, sizeof *info);
if (info == NULL)
return false;
/* FIXME: When using the linker --split-by-file or
--split-by-reloc options, it is possible for the .stab and
.stabstr sections to be split. We should handle that. */
info->stabsec = bfd_get_section_by_name (abfd, ".stab");
info->strsec = bfd_get_section_by_name (abfd, ".stabstr");
if (info->stabsec == NULL || info->strsec == NULL)
{
/* No stabs debugging information. Set *pinfo so that we
can return quickly in the info != NULL case above. */
*pinfo = info;
return true;
}
stabsize = info->stabsec->_raw_size;
strsize = info->strsec->_raw_size;
info->stabs = (bfd_byte *) bfd_alloc (abfd, stabsize);
info->strs = (bfd_byte *) bfd_alloc (abfd, strsize);
if (info->stabs == NULL || info->strs == NULL)
return false;
if (! bfd_get_section_contents (abfd, info->stabsec, info->stabs, 0,
stabsize)
|| ! bfd_get_section_contents (abfd, info->strsec, info->strs, 0,
strsize))
return false;
/* If this is a relocateable object file, we have to relocate
the entries in .stab. This should always be simple 32 bit
relocations against symbols defined in this object file, so
this should be no big deal. */
reloc_size = bfd_get_reloc_upper_bound (abfd, info->stabsec);
if (reloc_size < 0)
return false;
reloc_vector = (arelent **) bfd_malloc (reloc_size);
if (reloc_vector == NULL && reloc_size != 0)
return false;
reloc_count = bfd_canonicalize_reloc (abfd, info->stabsec, reloc_vector,
symbols);
if (reloc_count < 0)
{
if (reloc_vector != NULL)
free (reloc_vector);
return false;
}
if (reloc_count > 0)
{
arelent **pr;
for (pr = reloc_vector; *pr != NULL; pr++)
{
arelent *r;
unsigned long val;
asymbol *sym;
r = *pr;
if (r->howto->rightshift != 0
|| r->howto->size != 2
|| r->howto->bitsize != 32
|| r->howto->pc_relative
|| r->howto->bitpos != 0
|| r->howto->dst_mask != 0xffffffff)
{
(*_bfd_error_handler)
("Unsupported .stab relocation");
bfd_set_error (bfd_error_invalid_operation);
if (reloc_vector != NULL)
free (reloc_vector);
return false;
}
val = bfd_get_32 (abfd, info->stabs + r->address);
val &= r->howto->src_mask;
sym = *r->sym_ptr_ptr;
val += sym->value + sym->section->vma + r->addend;
bfd_put_32 (abfd, val, info->stabs + r->address);
}
}
if (reloc_vector != NULL)
free (reloc_vector);
*pinfo = info;
}
/* We are passed a section relative offset. The offsets in the
stabs information are absolute. */
offset += bfd_get_section_vma (abfd, section);
/* Stabs entries use a 12 byte format:
4 byte string table index
1 byte stab type
1 byte stab other field
2 byte stab desc field
4 byte stab value
FIXME: This will have to change for a 64 bit object format.
The stabs symbols are divided into compilation units. For the
first entry in each unit, the type of 0, the value is the length
of the string table for this unit, and the desc field is the
number of stabs symbols for this unit. */
#define STRDXOFF (0)
#define TYPEOFF (4)
#define OTHEROFF (5)
#define DESCOFF (6)
#define VALOFF (8)
#define STABSIZE (12)
/* It would be nice if we could skip ahead to the stabs symbols for
the next compilation unit to quickly scan through the compilation
units. Unfortunately, since each line number gets a separate
stabs entry, it is entirely plausible that a large source file
will overflow the 16 bit count of stabs entries. */
fnaddr = 0;
directory_name = NULL;
main_file_name = NULL;
current_file_name = NULL;
line_file_name = NULL;
fnname = NULL;
low_func_vma = 0;
low_line_vma = 0;
stabend = info->stabs + stabsize;
if (info->cached_stab == NULL || offset < info->cached_offset)
{
stab = info->stabs;
str = info->strs;
stroff = 0;
}
else
{
stab = info->cached_stab;
str = info->cached_str;
stroff = info->cached_stroff;
}
info->cached_offset = offset;
for (; stab < stabend; stab += STABSIZE)
{
boolean done;
bfd_vma val;
char *name;
done = false;
switch (stab[TYPEOFF])
{
case 0:
/* This is the first entry in a compilation unit. */
if ((bfd_size_type) ((info->strs + strsize) - str) < stroff)
{
done = true;
break;
}
str += stroff;
stroff = bfd_get_32 (abfd, stab + VALOFF);
break;
case N_SO:
/* The main file name. */
val = bfd_get_32 (abfd, stab + VALOFF);
if (val > offset)
{
done = true;
break;
}
name = str + bfd_get_32 (abfd, stab + STRDXOFF);
/* An empty string indicates the end of the compilation
unit. */
if (*name == '\0')
{
/* If there are functions in different sections, they
may have addresses larger than val, but we don't want
to forget the file name. When there are functions in
different cases, there is supposed to be an N_FUN at
the end of the function indicating where it ends. */
if (low_func_vma < val || fnname == NULL)
main_file_name = NULL;
break;
}
/* We know that we have to get to at least this point in the
stabs entries for this offset. */
info->cached_stab = stab;
info->cached_str = str;
info->cached_stroff = stroff;
current_file_name = name;
/* Look ahead to the next symbol. Two consecutive N_SO
symbols are a directory and a file name. */
if (stab + STABSIZE >= stabend
|| *(stab + STABSIZE + TYPEOFF) != N_SO)
directory_name = NULL;
else
{
stab += STABSIZE;
directory_name = current_file_name;
current_file_name = str + bfd_get_32 (abfd, stab + STRDXOFF);
}
main_file_name = current_file_name;
break;
case N_SOL:
/* The name of an include file. */
current_file_name = str + bfd_get_32 (abfd, stab + STRDXOFF);
break;
case N_SLINE:
case N_DSLINE:
case N_BSLINE:
/* A line number. The value is relative to the start of the
current function. */
val = fnaddr + bfd_get_32 (abfd, stab + VALOFF);
if (val >= low_line_vma && val <= offset)
{
*pline = bfd_get_16 (abfd, stab + DESCOFF);
low_line_vma = val;
line_file_name = current_file_name;
}
break;
case N_FUN:
/* A function name. */
val = bfd_get_32 (abfd, stab + VALOFF);
name = str + bfd_get_32 (abfd, stab + STRDXOFF);
/* An empty string here indicates the end of a function, and
the value is relative to fnaddr. */
if (*name == '\0')
{
val += fnaddr;
if (val >= low_func_vma && val < offset)
fnname = NULL;
}
else
{
if (val >= low_func_vma && val <= offset)
{
fnname = name;
low_func_vma = val;
}
fnaddr = val;
}
break;
}
if (done)
break;
}
if (main_file_name == NULL)
{
/* No information found. */
return true;
}
*pfound = true;
if (*pline != 0)
main_file_name = line_file_name;
if (main_file_name != NULL)
{
if (main_file_name[0] == '/' || directory_name == NULL)
*pfilename = main_file_name;
else
{
size_t dirlen;
dirlen = strlen (directory_name);
if (info->filename == NULL
|| strncmp (info->filename, directory_name, dirlen) != 0
|| strcmp (info->filename + dirlen, main_file_name) != 0)
{
if (info->filename != NULL)
free (info->filename);
info->filename = (char *) bfd_malloc (dirlen +
strlen (main_file_name)
+ 1);
if (info->filename == NULL)
return false;
strcpy (info->filename, directory_name);
strcpy (info->filename + dirlen, main_file_name);
}
*pfilename = info->filename;
}
}
if (fnname != NULL)
{
char *s;
/* This will typically be something like main:F(0,1), so we want
to clobber the colon. It's OK to change the name, since the
string is in our own local storage anyhow. */
s = strchr (fnname, ':');
if (s != NULL)
*s = '\0';
*pfnname = fnname;
}
return true;
}
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