Commit Graph

105207 Commits

Author SHA1 Message Date
Tom Tromey
39f288bea9 Split out eval_op_plus
This splits UNOP_PLUS into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_plus): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:02 -07:00
Tom Tromey
eed70b1c37 Split out eval_op_repeat
This splits BINOP_REPEAT into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_repeat): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:02 -07:00
Tom Tromey
60cdd4871a Split out eval_op_leq
This splits BINOP_LEQ into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_leq): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:02 -07:00
Tom Tromey
96e3efd9b2 Split out eval_op_geq
This splits BINOP_GEQ into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_geq): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:02 -07:00
Tom Tromey
1f78d732ec Split out eval_op_gtr
This splits BINOP_GTR into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_gtr): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:01 -07:00
Tom Tromey
6cad134942 Split out eval_op_less
This splits BINOP_LESS into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_less): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:01 -07:00
Tom Tromey
1fcb355938 Split out eval_op_notequal
This splits BINOP_NOTEQUAL into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_notequal): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:01 -07:00
Tom Tromey
0cc96de858 Split out eval_op_equal
This splits BINOP_EQUAL into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_equal): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:01 -07:00
Tom Tromey
288d26bcd8 Split out eval_op_subscript
This splits BINOP_SUBSCRIPT into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_subscript): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:00 -07:00
Tom Tromey
7cdcdd02b3 Split out eval_op_binary
This splits out a new eval_op_binary helper function.  This function
can handle several different binary operations:

    case BINOP_EXP:
    case BINOP_MUL:
    case BINOP_DIV:
    case BINOP_INTDIV:
    case BINOP_REM:
    case BINOP_MOD:
    case BINOP_LSH:
    case BINOP_RSH:
    case BINOP_BITWISE_AND:
    case BINOP_BITWISE_IOR:
    case BINOP_BITWISE_XOR:

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_binary): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:00 -07:00
Tom Tromey
d9790e22f4 Split out eval_op_sub
This splits BINOP_SUB into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_sub): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:00 -07:00
Tom Tromey
aedaf9ac06 Split out eval_op_add
This splits BINOP_ADD into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_add): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:00 -07:00
Tom Tromey
b7a96ed22e Split out eval_op_member
This splits STRUCTOP_MEMBER into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_member): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:28:00 -07:00
Tom Tromey
fb461aa39e Split out eval_op_structop_ptr
This splits STRUCTOP_PTR into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_structop_ptr): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:59 -07:00
Tom Tromey
3e96c4fc0f Split out eval_op_structop_struct
This splits STRUCTOP_STRUCT into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_structop_struct): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:59 -07:00
Tom Tromey
f960a6176a Split out eval_op_ternop
This splits TERNOP_SLICE into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_ternop): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:59 -07:00
Tom Tromey
5c2f201e8d Split out eval_op_concat
This splits BINOP_CONCAT into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_concat): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:59 -07:00
Tom Tromey
f871bae1ae Split out eval_op_objc_selector
This splits OP_OBJC_SELECTOR into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_objc_selector): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:58 -07:00
Tom Tromey
14a1c64a13 Split out eval_op_string
This splits OP_STRING into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_string): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:58 -07:00
Tom Tromey
ffff730bf6 Split out eval_op_register
This splits OP_REGISTER into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_register): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:58 -07:00
Tom Tromey
9b1d8af683 Split out eval_op_func_static_var
This splits OP_FUNC_STATIC_VAR into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_func_static_var): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:58 -07:00
Tom Tromey
c0df928969 Split out eval_op_var_msym_value
This splits OP_VAR_MSYM_VALUE into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_var_msym_value): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:58 -07:00
Tom Tromey
50b98adc3c Split out eval_op_var_entry_value
This splits OP_VAR_ENTRY_VALUE into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_var_entry_value): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:57 -07:00
Tom Tromey
ea2d29f7bc Split out eval_op_scope
This splits OP_SCOPE into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_scope): New function.
	(evaluate_subexp_standard): Use it.
2021-03-08 07:27:57 -07:00
Mike Frysinger
8c9b6e7689 sim: delete unused BUILD_LIBS setting
This hasn't been initialized anywhere for years.  It used to be for
passing in the path to libiberty, but that stopped happening long ago.
Delete it to simplify the build logic.
2021-03-08 00:54:37 -05:00
Mike Frysinger
2916e3e18f sim: igen: update options API
This local macro doesn't take any args, so adjust the API to match.
No one really noticed as this is behind code that is not normally
built, only when a dev specifically tries to compile it.
2021-03-07 22:03:00 -05:00
GDB Administrator
d3dacd0faf Automatic date update in version.in 2021-03-08 00:00:26 +00:00
Jeff Law
f4df849f1d Regenerated 2021-03-07 16:03:49 -07:00
Mike Frysinger
6c57b87fc4 sim: testsuite: merge into toplevel automake
This allows us to delete most of our custom test logic,
and avoids a recursive make for minor speed up.
2021-03-07 15:54:53 -05:00
Mike Frysinger
6bddc3e8b4 sim: switch top level to automake
This doesn't gain us much by itself, but it sets us up for using more
features as we try to unify ports and avoid recursive make.
2021-03-07 13:41:45 -05:00
GDB Administrator
7ce45db691 Automatic date update in version.in 2021-03-07 00:00:23 +00:00
Tom Tromey
01573d7360 Fix build bug in ada-lang.c
An earlier patch of mine introduced a build failure in ada-lang.c.  A
couple of "to_string" calls were not namespace-qualified.  In the
failing setup, the std string_view is being used, and so (apparently)
ADL doesn't find gdb::to_string.

This patch, from the bug, fixes the problem.

gdb/ChangeLog
2021-03-06  Chernov Sergey  <klen_s@mail.ru>

	PR gdb/27528:
	* ada-lang.c (ada_fold_name): Use gdb::to_string.
2021-03-06 09:38:26 -07:00
Tom Tromey
9938d15a01 Move dwarf2_get_dwz_file to dwarf2/dwz.h
This moves dwarf2_get_dwz_file and some helper code to dwarf2/dwz.h.
The main benefit of this is just shrinking dwarf2/read.c a little bit.

gdb/ChangeLog
2021-03-06  Tom Tromey  <tom@tromey.com>

	* dwarf2/sect-names.h (dwarf2_elf_names): Declare.
	* dwarf2/read.h (dwarf2_get_dwz_file): Move to dwz.h.
	* dwarf2/read.c (dwarf2_elf_names): No longer static.
	(locate_dwz_sections, dwz_search_other_debugdirs)
	(dwarf2_get_dwz_file): Move to dwz.c.
	* dwarf2/dwz.h (dwarf2_get_dwz_file): Move declaration from
	read.h.
	* dwarf2/dwz.c (locate_dwz_sections, dwz_search_other_debugdirs)
	(dwarf2_get_dwz_file): Move from read.c.
2021-03-06 09:26:40 -07:00
Tom Tromey
1803565556 Include scoped_fd.h in debuginfod-support.h
debuginfod-support.h requires scoped_fd, so include the header here.

gdb/ChangeLog
2021-03-06  Tom Tromey  <tom@tromey.com>

	* debuginfod-support.h: Include scoped_fd.h.
2021-03-06 09:26:39 -07:00
Tom Tromey
a7308ce01e Avoid crash on missing dwz file
If DWARF contains a reference to a "dwz" file, but there is no
.gnu_debugaltlink section, then gdb will crash.  This happens because
dwarf2_get_dwz_file will return NULL, but some callers do not expect
this.

This patch changes dwarf2_get_dwz_file so that callers can require a
dwz file.  Then, it updates the callers that are attempting to process
references to the dwz file to require one.

This includes a new testcase.  The dwarf.exp changes don't handle the
new forms exactly correctly -- they are only handled well enough to
let this test case complete.

gdb/ChangeLog
2021-03-06  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.h (dwarf2_get_dwz_file): Add 'require' parameter.
	* dwarf2/read.c (dwarf2_get_dwz_file): Add 'require' parameter.
	(get_abbrev_section_for_cu, read_attribute_value)
	(get_debug_line_section): Update.
	* dwarf2/macro.c (dwarf_decode_macro_bytes): Update.

gdb/testsuite/ChangeLog
2021-03-06  Tom Tromey  <tom@tromey.com>

	* lib/dwarf.exp (_handle_DW_FORM): Treat DW_FORM_GNU_ref_alt and
	DW_FORM_GNU_strp_alt like DW_FORM_sec_offset.
	* gdb.dwarf2/dwznolink.exp: New file.
2021-03-06 09:26:39 -07:00
Tom Tromey
fbedd54644 Change section_is_p to a method on dwarf2_section_names
This replaces section_is_p with a method on dwarf2_section_names.

gdb/ChangeLog
2021-03-06  Tom Tromey  <tom@tromey.com>

	* dwarf2/sect-names.h (struct dwarf2_section_names) <matches>: New
	method.
	* dwarf2/read.c (section_is_p): Remove.
	(dwarf2_per_bfd::locate_sections)
	(dwarf2_per_bfd::locate_sections, locate_dwz_sections)
	(locate_v1_virtual_dwo_sections, dwarf2_locate_dwo_sections)
	(dwarf2_locate_common_dwp_sections)
	(dwarf2_locate_v2_dwp_sections, dwarf2_locate_v5_dwp_sections):
	Update.
2021-03-06 09:26:39 -07:00
Tom Tromey
c2a62a3d88 Create new file dwarf2/sect-names.h
This creates a new file, dwarf2/sect-names.h, and moves some
DWARF-specific type definitions from symfile.h into it.

gdb/ChangeLog
2021-03-06  Tom Tromey  <tom@tromey.com>

	* xcoffread.c: Include sect-names.h.
	* symfile.h (struct dwarf2_section_names, struct
	dwarf2_debug_sections): Move to dwarf2/sect-names.h.
	* dwarf2/sect-names.h: New file, from symfile.h.
	* dwarf2/read.c: Include sect-names.h.
2021-03-06 09:26:39 -07:00
Tom Tromey
4444f40757 Micro-optimize abbrev reading and storage
Currently, and abbrev_info points to a separately allocated array of
attr_abbrev objects.  This array is constructed in a temporary vector,
then copied to the abbrev table's obstack.

This patch changes abbrev_info to use the struct hack to store the
objects directly, and changes abbrev_table::read to avoid an extra
copy when allocating, using the "growing objects" capability of
obstacks.

This saves a bit of space, and also perhaps a little time.

2021-03-06  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.c (read_attribute): Make 'abbrev' const.
	* dwarf2/abbrev.c (abbrev_table::alloc_abbrev): Remove.
	(abbrev_table::read): Update.
	* dwarf2/abbrev.h (struct attr_abbrev): Move earlier.
	(struct abbrev_info): Reformat.
	<attrs>: Now an array.
	(struct abbrev_table) <alloc_abbrev>: Remove.
2021-03-06 09:17:28 -07:00
H.J. Lu
8c0546e928 elf/x86-64: Subtract __ImageBase for R_AMD64_IMAGEBASE
When linking Windows x86-64 relocatable object files to generate x86-64
ELF executable, we need to subtract __ImageBase, aka __executable_start,
for R_AMD64_IMAGEBASE relocation:

1. Add link_info to struct output_elf_obj_tdata to store linker info and
_bfd_get_link_info() to retrieve it.
2. Add ldelf_set_output_arch to set up link_info.
3. Add pex64_link_add_symbols to create an indirect reference to
__executable_start for __ImageBase to support R_AMD64_IMAGEBASE relocation
when adding symbols from Windows x86-64 relocatable object files to
generate x86-64 ELF executable.
4. Also subtract __ImageBase for R_AMD64_IMAGEBASE when generating x86-64
ELF executable.

bfd/

	PR ld/27425
	PR ld/27432
	* bfd.c (_bfd_get_link_info): New function.
	* elf-bfd.h (output_elf_obj_tdata): Add link_info.
	(elf_link_info): New.
	* libbfd-in.h (_bfd_get_link_info): New prototype.
	* coff-x86_64.c (coff_amd64_reloc): Also subtract __ImageBase for
	R_AMD64_IMAGEBASE when generating x86-64 ELF executable.
	* pe-x86_64.c: Include "coff/internal.h" and "libcoff.h".
	(pex64_link_add_symbols): New function.
	(coff_bfd_link_add_symbols): New macro.
	* libbfd.h: Regenerated.

ld/

	PR ld/27425
	PR ld/27432
	* ldelf.c (ldelf_set_output_arch): New function.
	* ldelf.h (ldelf_set_output_arch): New prototype.
	* emultempl/elf.em (LDEMUL_SET_OUTPUT_ARCH): Default to
	ldelf_set_output_arch.
	* ld-x86-64/pe-x86-64-1.od: Expect __executable_start.
	* testsuite/ld-x86-64/pe-x86-64-2.od: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-3.od: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-4.od: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-5.od: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-5.rd: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-6.obj.bz2: New file.
	* testsuite/ld-x86-64/pe-x86-64-6.od: Likewise.
	* testsuite/ld-x86-64/pe-x86-64.exp: Run ld/27425 test.
2021-03-05 18:25:06 -08:00
Mark Wielaard
b0a8c2ff9c Make valgrind tests more robust by adding --wait=1 to vgdb invocation
On my setup some valgrind tests failed somewhat reliably because
the target remote | vgdb command couldn't find the vgdb-pipe files
because valgrind startup hadn't finished yet.

I tried to fix this by replacing the "Memcheck, a memory error detector"
match to "TO DEBUG THIS PROCESS USING GDB: start GDB like this" which is
right before valgrind creates the vgdb-pipe files. But even that didn't
guarantee that the vgdb-pipe files were there (maybe valgrind should
print that text after it has created them?). But also not all tests
use --vgdb-error=0, so the text isn't always printed.

To make the tests reliable I added --wait=1 to the vgdb invocation.
That tells vgdb to try to find the vgdb-pipe files, and if they aren't
there yet, to wait 1 second and try again.

gdb/testsuite/ChangeLog:

	* lib/valgrind.exp (vgdb_start): Add --wait=1 to vgdbcmd.
2021-03-06 02:51:04 +01:00
Weimin Pan
dd99cf0c58 CTF: add all members of an enum type to psymtab
With the following change which was made last April:

    [gdb] Use partial symbol table to find language for main
    commit d321419811

The ctf reader was modified to enter all members of an enum type,
similar to what the dwarf2 reader did, into the psymtab or gdb
won't be able to find them. In addition, the empty name checking
needed to be moved down so members of a unnamed enum were not left
out.

gdb/ChangeLog:

	* ctfread.c (ctf_psymtab_add_enums): New function.
	(ctf_psymtab_type_cb): call ctf_psymtab_add_enums.
2021-03-05 20:46:39 -05:00
Weimin Pan
844be3f240 CTF: set up debug info for function arguments
Added this support in read_func_kind_type after gcc started generating
CTF for function arguments.

Replaced XNEW with std::vector and NULL with nullptr.

Expanded gdb.base/ctf-ptype.exp to test function arguments. Also fixed
some typos.

gdb/ChangeLog:

	* ctfread.c (read_func_kind_type): Set up function arguments.

gdb/testsuite/ChangeLog:

	* gdb.base/ctf-ptype.exp: Add function tests and fix typos.
2021-03-05 20:46:39 -05:00
GDB Administrator
019989fdf1 Automatic date update in version.in 2021-03-06 00:00:16 +00:00
Andrew Burgess
b2668f28ee gdb/riscv: write CSRs into baremetal core dumps
Use the current target description to include CSRs into the RISC-V
baremetal core dumps.

Every CSR declared in the current target description will be included
in the core dump.

It will be critical for users that they have the same target
description in use when loading the core file as was in use when
writing the core file.  This should be fine if the user allows the
target description to be written into the core file.

In more detail, this commit adds a NT_RISCV_CSR note type.  The
contents of this section is a series of either 4-byte (on RV32
targets), or 8-byte (on RV64 targets) values.  Every CSR that is
mentioned in the current target description is written out in the
order the registers appear in the target description.  As a
consequence it is critical that the exact same target description,
including the same register order, is in use when the CSRs are loaded
from the core file.

gdb/ChangeLog:

	* riscv-none-tdep.c: Add 'user-regs.h' and 'target-description.h'
	includes.
	(riscv_csrset): New static global.
	(riscv_update_csrmap): New function.
	(riscv_iterate_over_regset_sections): Process CSRs.
2021-03-05 17:21:41 +00:00
Andrew Burgess
d782d24b32 gdb/riscv: make riscv target description names global
A later commit will need the names of the RISC-V target description
features in files other than riscv-tdep.c.  This commit just makes the
names global strings that can be accessed from other riscv-*.c files.

There should be no user visible changes after this commit.

gdb/ChangeLog:

        * riscv-tdep.c (riscv_feature_name_csr): Define.
        (riscv_feature_name_cpu): Define.
        (riscv_feature_name_fpu): Define.
        (riscv_feature_name_virtual): Define.
        (riscv_xreg_feature): Use riscv_feature_name_cpu.
        (riscv_freg_feature): Use riscv_feature_name_fpu.
        (riscv_virtual_feature): Use riscv_feature_name_virtual.
        (riscv_csr_feature): Use riscv_feature_name_csr.
        * riscv-tdep.h (riscv_feature_name_csr): Declare.
2021-03-05 17:21:41 +00:00
Andrew Burgess
db6092f3ae bfd/binutils: add support for RISC-V CSRs in core files
Adds support for including RISC-V control and status registers into
core files.

The value for the define NT_RISCV_CSR is set to 0x900, this
corresponds to a patch I have proposed for the Linux kernel here:

  http://lists.infradead.org/pipermail/linux-riscv/2020-December/003910.html

As I have not yet heard if the above patch will be accepted into the
kernel or not I have set the note name string to "GDB", and the note
type to NT_RISCV_CSR.

This means that if the above patch is rejected from the kernel, and
the note type number 0x900 is assigned to some other note type, we
will still be able to distinguish between the GDB produced
NT_RISCV_CSR, and the kernel produced notes, where the name would be
set to "CORE".

bfd/ChangeLog:

	* elf-bfd.h (elfcore_write_riscv_csr): Declare.
	* elf.c (elfcore_grok_riscv_csr): New function.
	(elfcore_grok_note): Handle NT_RISCV_CSR.
	(elfcore_write_riscv_csr): New function.
	(elfcore_write_register_note): Handle '.reg-riscv-csr'.

binutils/ChangeLog:

	* readelf.c (get_note_type): Handle NT_RISCV_CSR.

include/ChangeLog:

	* elf/common.h (NT_RISCV_CSR): Define.
2021-03-05 17:21:41 +00:00
Andrew Burgess
fb8f3fc0c3 gdb/riscv: introduce bare metal core dump support
This commit adds the ability for bare metal RISC-V target to generate
core files from within GDB.

The intended use case is that a user will connect to a remote bare
metal target, debug up to some error condition, then generate a core
file in the normal way using:

  (gdb) generate-core-file

This core file can then be used to revisit the state of the remote
target without having to reconnect to the remote target.

The core file creation code is split between two new files.  In
elf-none-tdep.c is code for any architecture with the none
ABI (i.e. bare metal) when the BFD library is built with ELF support.

In riscv-none-tdep.c are the RISC-V specific parts.  This is where the
regset and regcache_map_entry structures are defined that control how
registers are laid out in the core file.  As this file could (in
theory at least) be used for a non-ELF bare metal RISC-V target, the
calls into elf-none-tdep.c are guarded with '#ifdef HAVE_ELF'.

Currently for RISC-V only the x-regs and f-regs (if present) are
written out.  In future commits I plan to add support for writing out
the RISC-V CSRs.

The core dump format is based around generating an ELF containing
sections for the writable regions of memory that a user could be
using.  Which regions are dumped rely on GDB's existing common core
dumping code, GDB will attempt to figure out the stack and heap as
well as copying out writable data sections as identified by the
original ELF.

Register information is added to the core dump using notes, just as it
is for Linux of FreeBSD core dumps.  The note types used consist of
the 3 basic types you would expect in a OS based core dump,
NT_PRPSINFO, NT_PRSTATUS, NT_FPREGSET.

The layout of these notes differs slightly (due to field sizes)
between RV32 and RV64.  Below I describe the data layout for each
note.  In all cases, all padding fields should be set to zero.

Note NT_PRPSINFO is optional.  Its data layout is:

  struct prpsinfo32_t		/* For RV32.  */
  {
    uint8_t padding[32];
    char fname[16];
    char psargs[80];
  }

  struct prpsinfo64_t		/* For RV64.  */
  {
    uint8_t padding[40];
    char fname[16];
    char psargs[80];
  }

Field 'fname' - null terminated string consisting of the basename of
    (up to the fist 15 characters of) the executable.  Any additional
    space should be set to zero.  If there's no executable name then
    this field can be set to all zero.

Field 'psargs' - a null terminated string up to 80 characters in
    length.  Any additional space should be filled with zero.  This
    field contains the full executable path and any arguments passed
    to the executable.  If there's nothing sensible to write in this
    field then fill it with zero.

Note NT_PRSTATUS is required, its data layout is:

  struct prstatus32_t		/* For RV32.  */
  {
    uint8_t padding_1[12];
    uint16_t sig;
    uint8_t padding_2[10];
    uint32_t thread_id;
    uint8_t padding_3[44];
    uint32_t x_regs[32];
    uint8_t padding_4[4];
  }

  struct prstatus64_t		/* For RV64.  */
  {
    uint8_t padding_1[12];
    uint16_t sig;
    uint8_t padding_2[18];
    uint32_t thread_id;
    uint8_t padding_3[76];
    uint64_t x_regs[32];
    uint8_t padding_4[4];
  }

Field 'sig' - the signal that stopped this thread.  It's implementation
    defined what this field actually means.  Within GDB this will be
    the signal number that the remote target reports as the stop
    reason for this thread.

Field 'thread_is' - the thread id for this thread.  It's implementation
    defined what this field actually means.  Within GDB this will be
    thread thread-id that is assigned to each remote thread.

Field 'x_regs' - at index 0 we store the program counter, and at
    indices 1 to 31 we store x-registers 1 to 31.  x-register 0 is not
    stored, its value is always zero anyway.

Note NT_FPREGSET is optional, its data layout is:

  fpregset32_t			/* For targets with 'F' extension.  */
  {
    uint32_t f_regs[32];
    uint32_t fcsr;
  }

  fpregset64_t			/* For targets with 'D' extension .  */
  {
    uint64_t f_regs[32];
    uint32_t fcsr;
  }

Field 'f_regs' - stores f-registers 0 to 31.

Field 'fcsr' - stores the fcsr CSR register, and is always 4-bytes.

The rules for ordering the notes is the same as for Linux.  The
NT_PRSTATUS note must come before any other notes about additional
register sets.  And for multi-threaded targets all registers for a
single thread should be grouped together.  This is because only
NT_PRSTATUS includes a thread-id, all additional register notes after
a NT_PRSTATUS are assumed to belong to the same thread until a
different NT_PRSTATUS is seen.

gdb/ChangeLog:

	* Makefile.in (ALL_TARGET_OBS): Add riscv-none-tdep.o.
	(ALLDEPFILES): Add riscv-none-tdep.c.
	* configure: Regenerate.
	* configure.ac (CONFIG_OBS): Add elf-none-tdep.o when BFD has ELF
	support.
	* configure.tgt (riscv*-*-*): Include riscv-none-tdep.c.
	* elf-none-tdep.c: New file.
	* elf-none-tdep.h: New file.
	* riscv-none-tdep.c: New file.
2021-03-05 17:21:41 +00:00
Andrew Burgess
0897bb7d6d bfd/riscv: prepare to handle bare metal core dump creation
When creating a core file GDB will call the function
elfcore_write_prstatus to write out the general purpose registers
along with the pid/tid for the thread (into a prstatus structure) and
the executable name and arguments (into a prpsinfo_t structure).

However, for a bare metal RISC-V tool chain the prstatus_t and
prpsinfo_t types are not defined so the elfcore_write_prstatus
function will return NULL, preventing core file creation.

This commit provides the `elf_backend_write_core_note' hook and uses
the provided function to write out the required information.

In order to keep changes in the non bare metal tools to a minimum, the
provided backend function will itself return NULL when the prstatus_t
or pspsinfo_t types are available, the consequence of this is that the
generic code in elfcore_write_prstatus will be used just as before.
But, when prstatus_t or prpsinfo_t is not available, the new backend
function will write out the information using predefined offsets.

This new functionality will be used by a later GDB commit that will
add bare metal core dumps for RISC-V.

bfd/ChangeLog:

	* elfnn-riscv.c (PRPSINFO_PR_FNAME_LENGTH): Define.
	(PRPSINFO_PR_PSARGS_LENGTH): Define.
	(riscv_write_core_note): New function.
	(riscv_elf_grok_psinfo): Make use of two new length defines.
	(elf_backend_write_core_note): Define.
2021-03-05 17:21:41 +00:00
Andrew Burgess
95ce627aeb gdb: write target description into core file
When a core file is created from within GDB add the target description
into a note within the core file.

When loading a core file, if the target description note is present
then load the target description from the core file.

The benefit of this is that we can be sure that, when analysing the
core file within GDB, that we are using the exact same target
description as was in use at the time the core file was created.

GDB already supports a mechanism for figuring out the target
description from a given corefile; gdbarch_core_read_description.
This new mechanism (GDB adding the target description) is not going to
replace the old mechanism.  Core files generated outside of GDB will
not include a target description, and so GDB still needs to be able to
figure out a target description for these files.

My primary motivation for adding this feature is that, in a future
commit, I will be adding support for bare metal core dumps on some
targets.  For RISC-V specifically, I want to be able to dump all the
available control status registers.  As different targets will present
different sets of register in their target description, including
registers that are possibly not otherwise known to GDB I wanted a way
to capture these registers in the core dump.

I therefore need a mechanism to write out an arbitrary set of
registers, and to then derive a target description from this arbitrary
set when later loading the core file.  The obvious approach (I think)
is to just reuse the target description.

Once I'd decided to add support for writing out the target description
I could either choose to make this RISC-V only, or make it generic.  I
figure that having the target description in the core file doesn't
hurt, and _might_ be helpful.  So that's how I got here, general
support for including the target description in GDB generated core
files.

In previous versions of this patch I added the target description from
generic code (in gcore.c).  However, doing this creates a dependency
between GDB's common code and bfd ELF support.  As ELF support in gdb
is optional (for example the target x86_64-apple-darwin20.3.0 does not
include ELF support) then having gcore.c require ELF support would
break the GDB build in some cases.

Instead, in this version of the patch, writing the target description
note is done from each specific targets make notes function.  Each of
these now calls a common function in gcore-elf.c (which is only linked
in when bfd has ELF support).  And so only targets that are ELF based
will call the new function and we can therefore avoid an unconditional
dependency on ELF support.

gdb/ChangeLog:

	* corelow.c: Add 'xml-tdesc.h' include.
	(core_target::read_description): Load the target description from
	the core file when possible.
	* fbsd-tdep.c (fbsd_make_corefile_notes): Add target description
	note.
	* gcore-elf.c: Add 'gdbsupport/tdesc.h' include.
	(gcore_elf_make_tdesc_note): New function.
	* gcore-elf.h (gcore_elf_make_tdesc_note): Declare.
	* linux-tdep.c (linux_make_corefile_notes): Add target description
	note.
2021-03-05 17:21:41 +00:00
Andrew Burgess
b63a5e38ef bfd/binutils: support for gdb target descriptions in the core file
This commit lays the ground work for allowing GDB to write its target
description into a generated core file.

The goal of this work is to allow a user to connect to a remote
target, capture a core file from within GDB, then pass the executable
and core file to another user and have the user be able to examine the
state of the machine without needing to connect to a running target.

Different remote targets can have different register sets and this
information is communicated from the target to GDB in the target
description.

It is possible for a user to extract the target description from GDB
and pass this along with the core file so that when the core file is
used the target description can be fed back into GDB, however this is
not a great user experience.

It would be nicer, I think, if GDB could write the target description
directly into the core file, and then make use of this description
when loading a core file.

This commit performs the binutils/bfd side of this task, adding the
boiler plate functions to access the target description from within a
core file note, and reserving a new number for a note containing the
target description.  Later commits will extend GDB to make use of
this.

The new note is given the name 'GDB' and a type NT_GDB_TDESC.  This
should hopefully protect us if there's ever a reuse of the number
assigned to NT_GDB_TDESC by some other core file producer.  It should
also, hopefully, make it clearer to users that this note carries GDB
specific information.

bfd/ChangeLog:

	* elf-bfd.h (elfcore_write_gdb_tdesc): Declare new function.
	* elf.c (elfcore_grok_gdb_tdesc): New function.
	(elfcore_grok_note): Handle NT_GDB_TDESC.
	(elfcore_write_gdb_tdesc): New function.
	(elfcore_write_register_note): Handle NT_GDB_TDESC.

binutils/ChangeLog:

	* readelf.c (get_note_type): Handle NT_GDB_TDESC.

include/ChangeLog:

	* elf/common.h (NT_GDB_TDESC): Define.
2021-03-05 17:21:40 +00:00