gdb/17394: cannot put breakpoint only in selected ASM file.
This patch fixes a problem when trying to insert a breakpoint on
a specific symbol defined in a specific file, eg:
break foo.c:func
This currently works for files in C/C++/Ada, etc, but doesn't always
work for Asm files. Analysis of the problem showed that this related
to a limitation in gas, which does not generate debug info for functions/
symbols. Thus, we have a symtab for the file ("info sources" shows
the file), but it contains no symbols.
When find_linespec_symbols is called in linespec_parse_basic, it calls
find_function_symbols, which uses add_matching_symbols_to_info to
collect all matching symbols.
That function does [pardon any mangled formatting]:
for (ix = 0; VEC_iterate (symtab_ptr, info->file_symtabs, ix, elt); ++ix)
{
if (elt == NULL)
{
iterate_over_all_matching_symtabs (info->state, name, VAR_DOMAIN,
collect_symbols, info,
pspace, 1);
search_minsyms_for_name (info, name, pspace);
}
else if (pspace == NULL || pspace == SYMTAB_PSPACE (elt))
{
/* Program spaces that are executing startup should have
been filtered out earlier. */
gdb_assert (!SYMTAB_PSPACE (elt)->executing_startup);
set_current_program_space (SYMTAB_PSPACE (elt));
iterate_over_file_blocks (elt, name, VAR_DOMAIN,
collect_symbols, info);
}
}
This iterates over the symtabs. In the failing use case, ELT is
non-NULL (points to the symtab for the .s file), so it calls
iterate_over_file_blocks. Herein is where the problem exists: it is
assumed that if NAME exists, it must exist in the given symtab -- a
reasonable assumption for "normal" (non-asm) cases. It never searches
minimal symbols (or in the global default symtab).
This patch fixes the problem by doing so. It is important to note that
iterating over minsyms is fairly expensive, so this patch only adds
that extra search if the language is language_asm and
iterate_over_file_blocks returns no symbols.
gdb/ChangeLog:
2014-12-20 Keith Seitz <keiths@redhat.com>
Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* linespec.c (struct collect_minsyms): Add new member `symtab'.
(add_minsym): Handle cases where info.symtab is non-NULL.
(search_minsyms_for_name): Add new parameter `symtab'.
Handle limiting searches to a specific symtab.
(add_matching_symtabs_to_info): Search through minimal symbols
for language_asm files for which no new symbols are found.
gdb/testsuite/ChangeLog:
2014-12-20 Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* gdb.linespec/break-asm-file.c: New file.
* gdb.linespec/break-asm-file.exp: New file.
* gdb.linespec/break-asm-file0.s: New file.
* gdb.linespec/break-asm-file1.s: New file.
2014-12-21 00:04:44 +08:00
|
|
|
/* This testcase is part of GDB, the GNU debugger.
|
|
|
|
|
|
2017-01-01 14:50:51 +08:00
|
|
|
Copyright 2004-2017 Free Software Foundation, Inc.
|
gdb/17394: cannot put breakpoint only in selected ASM file.
This patch fixes a problem when trying to insert a breakpoint on
a specific symbol defined in a specific file, eg:
break foo.c:func
This currently works for files in C/C++/Ada, etc, but doesn't always
work for Asm files. Analysis of the problem showed that this related
to a limitation in gas, which does not generate debug info for functions/
symbols. Thus, we have a symtab for the file ("info sources" shows
the file), but it contains no symbols.
When find_linespec_symbols is called in linespec_parse_basic, it calls
find_function_symbols, which uses add_matching_symbols_to_info to
collect all matching symbols.
That function does [pardon any mangled formatting]:
for (ix = 0; VEC_iterate (symtab_ptr, info->file_symtabs, ix, elt); ++ix)
{
if (elt == NULL)
{
iterate_over_all_matching_symtabs (info->state, name, VAR_DOMAIN,
collect_symbols, info,
pspace, 1);
search_minsyms_for_name (info, name, pspace);
}
else if (pspace == NULL || pspace == SYMTAB_PSPACE (elt))
{
/* Program spaces that are executing startup should have
been filtered out earlier. */
gdb_assert (!SYMTAB_PSPACE (elt)->executing_startup);
set_current_program_space (SYMTAB_PSPACE (elt));
iterate_over_file_blocks (elt, name, VAR_DOMAIN,
collect_symbols, info);
}
}
This iterates over the symtabs. In the failing use case, ELT is
non-NULL (points to the symtab for the .s file), so it calls
iterate_over_file_blocks. Herein is where the problem exists: it is
assumed that if NAME exists, it must exist in the given symtab -- a
reasonable assumption for "normal" (non-asm) cases. It never searches
minimal symbols (or in the global default symtab).
This patch fixes the problem by doing so. It is important to note that
iterating over minsyms is fairly expensive, so this patch only adds
that extra search if the language is language_asm and
iterate_over_file_blocks returns no symbols.
gdb/ChangeLog:
2014-12-20 Keith Seitz <keiths@redhat.com>
Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* linespec.c (struct collect_minsyms): Add new member `symtab'.
(add_minsym): Handle cases where info.symtab is non-NULL.
(search_minsyms_for_name): Add new parameter `symtab'.
Handle limiting searches to a specific symtab.
(add_matching_symtabs_to_info): Search through minimal symbols
for language_asm files for which no new symbols are found.
gdb/testsuite/ChangeLog:
2014-12-20 Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* gdb.linespec/break-asm-file.c: New file.
* gdb.linespec/break-asm-file.exp: New file.
* gdb.linespec/break-asm-file0.s: New file.
* gdb.linespec/break-asm-file1.s: New file.
2014-12-21 00:04:44 +08:00
|
|
|
|
|
|
|
|
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 3 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, see <http://www.gnu.org/licenses/>. */
|
|
|
|
|
|
|
|
|
|
.file "a/break-asm-file0.s"
|
|
|
|
|
.text
|
|
|
|
|
.Lbegin_text1:
|
|
|
|
|
.globl _func2
|
|
|
|
|
_func2:
|
|
|
|
|
.globl func2
|
|
|
|
|
.type func2, %function
|
|
|
|
|
func2:
|
|
|
|
|
.Lbegin_func2:
|
2015-03-26 16:29:48 +08:00
|
|
|
nop
|
|
|
|
|
nop
|
gdb/17394: cannot put breakpoint only in selected ASM file.
This patch fixes a problem when trying to insert a breakpoint on
a specific symbol defined in a specific file, eg:
break foo.c:func
This currently works for files in C/C++/Ada, etc, but doesn't always
work for Asm files. Analysis of the problem showed that this related
to a limitation in gas, which does not generate debug info for functions/
symbols. Thus, we have a symtab for the file ("info sources" shows
the file), but it contains no symbols.
When find_linespec_symbols is called in linespec_parse_basic, it calls
find_function_symbols, which uses add_matching_symbols_to_info to
collect all matching symbols.
That function does [pardon any mangled formatting]:
for (ix = 0; VEC_iterate (symtab_ptr, info->file_symtabs, ix, elt); ++ix)
{
if (elt == NULL)
{
iterate_over_all_matching_symtabs (info->state, name, VAR_DOMAIN,
collect_symbols, info,
pspace, 1);
search_minsyms_for_name (info, name, pspace);
}
else if (pspace == NULL || pspace == SYMTAB_PSPACE (elt))
{
/* Program spaces that are executing startup should have
been filtered out earlier. */
gdb_assert (!SYMTAB_PSPACE (elt)->executing_startup);
set_current_program_space (SYMTAB_PSPACE (elt));
iterate_over_file_blocks (elt, name, VAR_DOMAIN,
collect_symbols, info);
}
}
This iterates over the symtabs. In the failing use case, ELT is
non-NULL (points to the symtab for the .s file), so it calls
iterate_over_file_blocks. Herein is where the problem exists: it is
assumed that if NAME exists, it must exist in the given symtab -- a
reasonable assumption for "normal" (non-asm) cases. It never searches
minimal symbols (or in the global default symtab).
This patch fixes the problem by doing so. It is important to note that
iterating over minsyms is fairly expensive, so this patch only adds
that extra search if the language is language_asm and
iterate_over_file_blocks returns no symbols.
gdb/ChangeLog:
2014-12-20 Keith Seitz <keiths@redhat.com>
Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* linespec.c (struct collect_minsyms): Add new member `symtab'.
(add_minsym): Handle cases where info.symtab is non-NULL.
(search_minsyms_for_name): Add new parameter `symtab'.
Handle limiting searches to a specific symtab.
(add_matching_symtabs_to_info): Search through minimal symbols
for language_asm files for which no new symbols are found.
gdb/testsuite/ChangeLog:
2014-12-20 Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* gdb.linespec/break-asm-file.c: New file.
* gdb.linespec/break-asm-file.exp: New file.
* gdb.linespec/break-asm-file0.s: New file.
* gdb.linespec/break-asm-file1.s: New file.
2014-12-21 00:04:44 +08:00
|
|
|
.Lend_func2:
|
|
|
|
|
.size func2, .-func2
|
|
|
|
|
.globl _func
|
|
|
|
|
_func:
|
|
|
|
|
.globl func
|
|
|
|
|
.type func, %function
|
|
|
|
|
func:
|
|
|
|
|
.Lbegin_func:
|
|
|
|
|
.file 1 "a/break-asm-file0.s"
|
2015-03-26 16:29:48 +08:00
|
|
|
nop
|
|
|
|
|
.Lfunc_1:
|
|
|
|
|
nop
|
Handle the effect of skipping prologue
break-asm-file.exp has some manually written dwarf to create some line
number entries like this,
[0x0000013d] Extended opcode 2: set Address to 0x40053f
[0x00000144] Advance Line by 4 to 7
[0x00000146] Copy
[0x00000147] Extended opcode 2: set Address to 0x400541
[0x0000014e] Advance Line by 1 to 8
[0x00000150] Copy
[0x00000151] Extended opcode 2: set Address to 0x400547
[0x00000158] Extended opcode 1: End of Sequence
0x40053f is the start address of function func, and is mapped to line
7. 0x400541 is within function func, and is mapped to line 8.
(gdb) disassemble /r 0x40053f,+8
Dump of assembler code from 0x40053f to 0x400547:
0x000000000040053f <func+0>: 00 00 add %al,(%rax)
0x0000000000400541 <func+2>: 00 00 add %al,(%rax)
0x0000000000400543 <func+4>: 00 00 add %al,(%rax)
0x0000000000400545 <func+6>: 00 00 add %al,(%rax)
in the following test,
(gdb) break a/break-asm-file0.s:func
Breakpoint 1 at 0x40053f: file a/break-asm-file0.s, line 7.
As we can see, breakpoint is set at the start address of function func
on x86, which means no prologue is skipped. On other targets, such as
arm and aarch64, breakpoint is set at the address *after* the start
address, which is mapped to line 8. Then test fails.
In fact, it is lucky this test doesn't fail on x86 and x86_64, whose
gdbarch method skip_prologue doesn't reply on skip_prologue_using_sal
if producer isn't clang.
if (find_pc_partial_function (start_pc, NULL, &func_addr, NULL))
{
CORE_ADDR post_prologue_pc
= skip_prologue_using_sal (gdbarch, func_addr);
struct compunit_symtab *cust = find_pc_compunit_symtab (func_addr);
/* Clang always emits a line note before the prologue and another
one after. We trust clang to emit usable line notes. */
if (post_prologue_pc
&& (cust != NULL
&& COMPUNIT_PRODUCER (cust) != NULL
&& startswith (COMPUNIT_PRODUCER (cust), "clang ")))
return max (start_pc, post_prologue_pc);
}
so it doesn't return and go further to prologue analyser. Since ".int 0"
isn't an instruction of prologue, nothing is skipped, starting address
is used, and test passes.
however, on targets which don't have such producer checking, the first
line number entry is skipped, and skip_prologue_using_sal returns sal
represents the second line number entry.
The idea of this patch is to force GDB stop at somewhere which is stilled
mapped to line 7 after skipping prologue. I choose to add a new line
number entry for the following instruction but mapped to the same line (7),
because I see the comments in dwarf2read.c,
... fact that two consecutive
line number entries for the same line is a heuristic used by gcc
to denote the end of the prologue.
then the line table becomes:
[0x000000d4] Extended opcode 2: set Address to 0x400529
[0x000000db] Advance Line by 4 to 7
[0x000000dd] Copy
[0x000000de] Extended opcode 2: set Address to 0x40052a
[0x000000e5] Advance Line by 0 to 7
[0x000000e7] Copy
[0x000000e8] Extended opcode 2: set Address to 0x40052b
[0x000000ef] Advance Line by 1 to 8
[0x000000f1] Copy
[0x000000f2] Extended opcode 2: set Address to 0x40052c
[0x000000f9] Extended opcode 1: End of Sequence
gdb/testsuite:
2015-03-26 Yao Qi <yao.qi@linaro.org>
PR testsuite/18139
* gdb.linespec/break-asm-file0.s (func): New label .Lfunc_2.
Add a line number entry for the same line.
* gdb.linespec/break-asm-file1.s (func): New label .Lfunc_2.
Add a line number entry for the same line.
2015-03-26 16:29:48 +08:00
|
|
|
.Lfunc_2:
|
|
|
|
|
nop
|
gdb/17394: cannot put breakpoint only in selected ASM file.
This patch fixes a problem when trying to insert a breakpoint on
a specific symbol defined in a specific file, eg:
break foo.c:func
This currently works for files in C/C++/Ada, etc, but doesn't always
work for Asm files. Analysis of the problem showed that this related
to a limitation in gas, which does not generate debug info for functions/
symbols. Thus, we have a symtab for the file ("info sources" shows
the file), but it contains no symbols.
When find_linespec_symbols is called in linespec_parse_basic, it calls
find_function_symbols, which uses add_matching_symbols_to_info to
collect all matching symbols.
That function does [pardon any mangled formatting]:
for (ix = 0; VEC_iterate (symtab_ptr, info->file_symtabs, ix, elt); ++ix)
{
if (elt == NULL)
{
iterate_over_all_matching_symtabs (info->state, name, VAR_DOMAIN,
collect_symbols, info,
pspace, 1);
search_minsyms_for_name (info, name, pspace);
}
else if (pspace == NULL || pspace == SYMTAB_PSPACE (elt))
{
/* Program spaces that are executing startup should have
been filtered out earlier. */
gdb_assert (!SYMTAB_PSPACE (elt)->executing_startup);
set_current_program_space (SYMTAB_PSPACE (elt));
iterate_over_file_blocks (elt, name, VAR_DOMAIN,
collect_symbols, info);
}
}
This iterates over the symtabs. In the failing use case, ELT is
non-NULL (points to the symtab for the .s file), so it calls
iterate_over_file_blocks. Herein is where the problem exists: it is
assumed that if NAME exists, it must exist in the given symtab -- a
reasonable assumption for "normal" (non-asm) cases. It never searches
minimal symbols (or in the global default symtab).
This patch fixes the problem by doing so. It is important to note that
iterating over minsyms is fairly expensive, so this patch only adds
that extra search if the language is language_asm and
iterate_over_file_blocks returns no symbols.
gdb/ChangeLog:
2014-12-20 Keith Seitz <keiths@redhat.com>
Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* linespec.c (struct collect_minsyms): Add new member `symtab'.
(add_minsym): Handle cases where info.symtab is non-NULL.
(search_minsyms_for_name): Add new parameter `symtab'.
Handle limiting searches to a specific symtab.
(add_matching_symtabs_to_info): Search through minimal symbols
for language_asm files for which no new symbols are found.
gdb/testsuite/ChangeLog:
2014-12-20 Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* gdb.linespec/break-asm-file.c: New file.
* gdb.linespec/break-asm-file.exp: New file.
* gdb.linespec/break-asm-file0.s: New file.
* gdb.linespec/break-asm-file1.s: New file.
2014-12-21 00:04:44 +08:00
|
|
|
.Lend_func:
|
|
|
|
|
.size func, .-func
|
|
|
|
|
.Lend_text1:
|
|
|
|
|
|
|
|
|
|
/* Debug information */
|
|
|
|
|
|
|
|
|
|
.section .debug_info
|
|
|
|
|
.Lcu1_begin:
|
|
|
|
|
/* CU header */
|
|
|
|
|
.4byte .Lcu1_end - .Lcu1_start /* Length of Compilation Unit */
|
|
|
|
|
.Lcu1_start:
|
|
|
|
|
.2byte 2 /* DWARF Version */
|
|
|
|
|
.4byte .Labbrev1_begin /* Offset into abbrev section */
|
|
|
|
|
.byte 4 /* Pointer size */
|
|
|
|
|
|
|
|
|
|
/* CU die */
|
|
|
|
|
.uleb128 1 /* Abbrev: DW_TAG_compile_unit */
|
|
|
|
|
.4byte .Lline1_begin /* DW_AT_stmt_list */
|
|
|
|
|
.4byte .Lend_text1 /* DW_AT_high_pc */
|
|
|
|
|
.4byte .Lbegin_text1 /* DW_AT_low_pc */
|
|
|
|
|
.ascii "a/break-asm-file0.s\0" /* DW_AT_name */
|
|
|
|
|
.ascii "GNU C 3.3.3\0" /* DW_AT_producer */
|
|
|
|
|
.2byte 0x8001 /* DW_AT_language (Mips Assembler) */
|
|
|
|
|
|
|
|
|
|
.byte 0 /* End of children of CU */
|
|
|
|
|
|
|
|
|
|
.Lcu1_end:
|
|
|
|
|
|
|
|
|
|
/* Abbrev table */
|
|
|
|
|
.section .debug_abbrev
|
|
|
|
|
.Labbrev1_begin:
|
|
|
|
|
.uleb128 1 /* Abbrev code */
|
|
|
|
|
.uleb128 0x11 /* DW_TAG_compile_unit */
|
|
|
|
|
.byte 1 /* has_children */
|
|
|
|
|
.uleb128 0x10 /* DW_AT_stmt_list */
|
|
|
|
|
.uleb128 0x6 /* DW_FORM_data4 */
|
|
|
|
|
.uleb128 0x12 /* DW_AT_high_pc */
|
|
|
|
|
.uleb128 0x1 /* DW_FORM_addr */
|
|
|
|
|
.uleb128 0x11 /* DW_AT_low_pc */
|
|
|
|
|
.uleb128 0x1 /* DW_FORM_addr */
|
|
|
|
|
.uleb128 0x3 /* DW_AT_name */
|
|
|
|
|
.uleb128 0x8 /* DW_FORM_string */
|
|
|
|
|
.uleb128 0x25 /* DW_AT_producer */
|
|
|
|
|
.uleb128 0x8 /* DW_FORM_string */
|
|
|
|
|
.uleb128 0x13 /* DW_AT_language */
|
|
|
|
|
.uleb128 0x5 /* DW_FORM_data2 */
|
|
|
|
|
.byte 0x0 /* Terminator */
|
|
|
|
|
.byte 0x0 /* Terminator */
|
|
|
|
|
|
|
|
|
|
.uleb128 2 /* Abbrev code */
|
|
|
|
|
.uleb128 0x2e /* DW_TAG_subprogram */
|
|
|
|
|
.byte 0 /* has_children */
|
|
|
|
|
.uleb128 0x3f /* DW_AT_external */
|
|
|
|
|
.uleb128 0xc /* DW_FORM_flag */
|
|
|
|
|
.uleb128 0x3a /* DW_AT_decl_file */
|
|
|
|
|
.uleb128 0xb /* DW_FORM_data1 */
|
|
|
|
|
.uleb128 0x3b /* DW_AT_decl_line */
|
|
|
|
|
.uleb128 0xb /* DW_FORM_data1 */
|
|
|
|
|
.uleb128 0x3 /* DW_AT_name */
|
|
|
|
|
.uleb128 0x8 /* DW_FORM_string */
|
|
|
|
|
.uleb128 0x49 /* DW_AT_type */
|
|
|
|
|
.uleb128 0x13 /* DW_FORM_ref4 */
|
|
|
|
|
.uleb128 0x11 /* DW_AT_low_pc */
|
|
|
|
|
.uleb128 0x1 /* DW_FORM_addr */
|
|
|
|
|
.uleb128 0x12 /* DW_AT_high_pc */
|
|
|
|
|
.uleb128 0x1 /* DW_FORM_addr */
|
|
|
|
|
.uleb128 0x40 /* DW_AT_frame_base */
|
|
|
|
|
.uleb128 0xa /* DW_FORM_block1 */
|
|
|
|
|
.byte 0x0 /* Terminator */
|
|
|
|
|
.byte 0x0 /* Terminator */
|
|
|
|
|
|
|
|
|
|
.uleb128 3 /* Abbrev code */
|
|
|
|
|
.uleb128 0x24 /* DW_TAG_base_type */
|
|
|
|
|
.byte 0 /* has_children */
|
|
|
|
|
.uleb128 0x3 /* DW_AT_name */
|
|
|
|
|
.uleb128 0x8 /* DW_FORM_string */
|
|
|
|
|
.uleb128 0xb /* DW_AT_byte_size */
|
|
|
|
|
.uleb128 0xb /* DW_FORM_data1 */
|
|
|
|
|
.uleb128 0x3e /* DW_AT_encoding */
|
|
|
|
|
.uleb128 0xb /* DW_FORM_data1 */
|
|
|
|
|
.byte 0x0 /* Terminator */
|
|
|
|
|
.byte 0x0 /* Terminator */
|
|
|
|
|
|
|
|
|
|
.byte 0x0 /* Terminator */
|
|
|
|
|
.byte 0x0 /* Terminator */
|
|
|
|
|
|
|
|
|
|
/* Line table */
|
|
|
|
|
.section .debug_line
|
|
|
|
|
.Lline1_begin:
|
|
|
|
|
.4byte .Lline1_end - .Lline1_start /* Initial length */
|
|
|
|
|
.Lline1_start:
|
|
|
|
|
.2byte 2 /* Version */
|
|
|
|
|
.4byte .Lline1_lines - .Lline1_hdr /* header_length */
|
|
|
|
|
.Lline1_hdr:
|
|
|
|
|
.byte 1 /* Minimum insn length */
|
|
|
|
|
.byte 1 /* default_is_stmt */
|
|
|
|
|
.byte 1 /* line_base */
|
|
|
|
|
.byte 1 /* line_range */
|
|
|
|
|
.byte 0x10 /* opcode_base */
|
|
|
|
|
|
|
|
|
|
/* Standard lengths */
|
|
|
|
|
.byte 0
|
|
|
|
|
.byte 1
|
|
|
|
|
.byte 1
|
|
|
|
|
.byte 1
|
|
|
|
|
.byte 1
|
|
|
|
|
.byte 0
|
|
|
|
|
.byte 0
|
|
|
|
|
.byte 0
|
|
|
|
|
.byte 1
|
|
|
|
|
.byte 0
|
|
|
|
|
.byte 0
|
|
|
|
|
.byte 1
|
|
|
|
|
.byte 0
|
|
|
|
|
.byte 0
|
|
|
|
|
.byte 0
|
|
|
|
|
|
|
|
|
|
/* Include directories */
|
|
|
|
|
.byte 0
|
|
|
|
|
|
|
|
|
|
/* File names */
|
|
|
|
|
.ascii "a/break-asm-file0.s\0"
|
|
|
|
|
.uleb128 0
|
|
|
|
|
.uleb128 0
|
|
|
|
|
.uleb128 0
|
|
|
|
|
|
|
|
|
|
.byte 0
|
|
|
|
|
|
|
|
|
|
.Lline1_lines:
|
|
|
|
|
.byte 0 /* DW_LNE_set_address */
|
|
|
|
|
.uleb128 5
|
|
|
|
|
.byte 2
|
|
|
|
|
.4byte .Lbegin_func2
|
|
|
|
|
|
|
|
|
|
.byte 3 /* DW_LNS_advance_line */
|
|
|
|
|
.sleb128 1 /* ... to 2 */
|
|
|
|
|
|
|
|
|
|
.byte 1 /* DW_LNS_copy */
|
|
|
|
|
|
|
|
|
|
.byte 0 /* DW_LNE_set_address */
|
|
|
|
|
.uleb128 5
|
|
|
|
|
.byte 2
|
|
|
|
|
.4byte .Lbegin_func2+1
|
|
|
|
|
|
|
|
|
|
.byte 3 /* DW_LNS_advance_line */
|
|
|
|
|
.sleb128 1 /* ... to 3 */
|
|
|
|
|
|
|
|
|
|
.byte 1 /* DW_LNS_copy */
|
|
|
|
|
|
|
|
|
|
.byte 0 /* DW_LNE_set_address */
|
|
|
|
|
.uleb128 5
|
|
|
|
|
.byte 2
|
|
|
|
|
.4byte .Lbegin_func
|
|
|
|
|
|
|
|
|
|
.byte 3 /* DW_LNS_advance_line */
|
|
|
|
|
.sleb128 4 /* ... to 7 */
|
|
|
|
|
|
|
|
|
|
.byte 1 /* DW_LNS_copy */
|
|
|
|
|
|
|
|
|
|
.byte 0 /* DW_LNE_set_address */
|
|
|
|
|
.uleb128 5
|
|
|
|
|
.byte 2
|
2015-03-26 16:29:48 +08:00
|
|
|
.4byte .Lfunc_1
|
gdb/17394: cannot put breakpoint only in selected ASM file.
This patch fixes a problem when trying to insert a breakpoint on
a specific symbol defined in a specific file, eg:
break foo.c:func
This currently works for files in C/C++/Ada, etc, but doesn't always
work for Asm files. Analysis of the problem showed that this related
to a limitation in gas, which does not generate debug info for functions/
symbols. Thus, we have a symtab for the file ("info sources" shows
the file), but it contains no symbols.
When find_linespec_symbols is called in linespec_parse_basic, it calls
find_function_symbols, which uses add_matching_symbols_to_info to
collect all matching symbols.
That function does [pardon any mangled formatting]:
for (ix = 0; VEC_iterate (symtab_ptr, info->file_symtabs, ix, elt); ++ix)
{
if (elt == NULL)
{
iterate_over_all_matching_symtabs (info->state, name, VAR_DOMAIN,
collect_symbols, info,
pspace, 1);
search_minsyms_for_name (info, name, pspace);
}
else if (pspace == NULL || pspace == SYMTAB_PSPACE (elt))
{
/* Program spaces that are executing startup should have
been filtered out earlier. */
gdb_assert (!SYMTAB_PSPACE (elt)->executing_startup);
set_current_program_space (SYMTAB_PSPACE (elt));
iterate_over_file_blocks (elt, name, VAR_DOMAIN,
collect_symbols, info);
}
}
This iterates over the symtabs. In the failing use case, ELT is
non-NULL (points to the symtab for the .s file), so it calls
iterate_over_file_blocks. Herein is where the problem exists: it is
assumed that if NAME exists, it must exist in the given symtab -- a
reasonable assumption for "normal" (non-asm) cases. It never searches
minimal symbols (or in the global default symtab).
This patch fixes the problem by doing so. It is important to note that
iterating over minsyms is fairly expensive, so this patch only adds
that extra search if the language is language_asm and
iterate_over_file_blocks returns no symbols.
gdb/ChangeLog:
2014-12-20 Keith Seitz <keiths@redhat.com>
Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* linespec.c (struct collect_minsyms): Add new member `symtab'.
(add_minsym): Handle cases where info.symtab is non-NULL.
(search_minsyms_for_name): Add new parameter `symtab'.
Handle limiting searches to a specific symtab.
(add_matching_symtabs_to_info): Search through minimal symbols
for language_asm files for which no new symbols are found.
gdb/testsuite/ChangeLog:
2014-12-20 Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* gdb.linespec/break-asm-file.c: New file.
* gdb.linespec/break-asm-file.exp: New file.
* gdb.linespec/break-asm-file0.s: New file.
* gdb.linespec/break-asm-file1.s: New file.
2014-12-21 00:04:44 +08:00
|
|
|
|
Handle the effect of skipping prologue
break-asm-file.exp has some manually written dwarf to create some line
number entries like this,
[0x0000013d] Extended opcode 2: set Address to 0x40053f
[0x00000144] Advance Line by 4 to 7
[0x00000146] Copy
[0x00000147] Extended opcode 2: set Address to 0x400541
[0x0000014e] Advance Line by 1 to 8
[0x00000150] Copy
[0x00000151] Extended opcode 2: set Address to 0x400547
[0x00000158] Extended opcode 1: End of Sequence
0x40053f is the start address of function func, and is mapped to line
7. 0x400541 is within function func, and is mapped to line 8.
(gdb) disassemble /r 0x40053f,+8
Dump of assembler code from 0x40053f to 0x400547:
0x000000000040053f <func+0>: 00 00 add %al,(%rax)
0x0000000000400541 <func+2>: 00 00 add %al,(%rax)
0x0000000000400543 <func+4>: 00 00 add %al,(%rax)
0x0000000000400545 <func+6>: 00 00 add %al,(%rax)
in the following test,
(gdb) break a/break-asm-file0.s:func
Breakpoint 1 at 0x40053f: file a/break-asm-file0.s, line 7.
As we can see, breakpoint is set at the start address of function func
on x86, which means no prologue is skipped. On other targets, such as
arm and aarch64, breakpoint is set at the address *after* the start
address, which is mapped to line 8. Then test fails.
In fact, it is lucky this test doesn't fail on x86 and x86_64, whose
gdbarch method skip_prologue doesn't reply on skip_prologue_using_sal
if producer isn't clang.
if (find_pc_partial_function (start_pc, NULL, &func_addr, NULL))
{
CORE_ADDR post_prologue_pc
= skip_prologue_using_sal (gdbarch, func_addr);
struct compunit_symtab *cust = find_pc_compunit_symtab (func_addr);
/* Clang always emits a line note before the prologue and another
one after. We trust clang to emit usable line notes. */
if (post_prologue_pc
&& (cust != NULL
&& COMPUNIT_PRODUCER (cust) != NULL
&& startswith (COMPUNIT_PRODUCER (cust), "clang ")))
return max (start_pc, post_prologue_pc);
}
so it doesn't return and go further to prologue analyser. Since ".int 0"
isn't an instruction of prologue, nothing is skipped, starting address
is used, and test passes.
however, on targets which don't have such producer checking, the first
line number entry is skipped, and skip_prologue_using_sal returns sal
represents the second line number entry.
The idea of this patch is to force GDB stop at somewhere which is stilled
mapped to line 7 after skipping prologue. I choose to add a new line
number entry for the following instruction but mapped to the same line (7),
because I see the comments in dwarf2read.c,
... fact that two consecutive
line number entries for the same line is a heuristic used by gcc
to denote the end of the prologue.
then the line table becomes:
[0x000000d4] Extended opcode 2: set Address to 0x400529
[0x000000db] Advance Line by 4 to 7
[0x000000dd] Copy
[0x000000de] Extended opcode 2: set Address to 0x40052a
[0x000000e5] Advance Line by 0 to 7
[0x000000e7] Copy
[0x000000e8] Extended opcode 2: set Address to 0x40052b
[0x000000ef] Advance Line by 1 to 8
[0x000000f1] Copy
[0x000000f2] Extended opcode 2: set Address to 0x40052c
[0x000000f9] Extended opcode 1: End of Sequence
gdb/testsuite:
2015-03-26 Yao Qi <yao.qi@linaro.org>
PR testsuite/18139
* gdb.linespec/break-asm-file0.s (func): New label .Lfunc_2.
Add a line number entry for the same line.
* gdb.linespec/break-asm-file1.s (func): New label .Lfunc_2.
Add a line number entry for the same line.
2015-03-26 16:29:48 +08:00
|
|
|
/* A line number entry for the same line (7) denotes the end */
|
|
|
|
|
/* of prologue. */
|
|
|
|
|
.byte 3 /* DW_LNS_advance_line */
|
|
|
|
|
.sleb128 0 /* ... to 7 */
|
|
|
|
|
|
|
|
|
|
.byte 1 /* DW_LNS_copy */
|
|
|
|
|
|
|
|
|
|
.byte 0 /* DW_LNE_set_address */
|
|
|
|
|
.uleb128 5
|
|
|
|
|
.byte 2
|
|
|
|
|
.4byte .Lfunc_2
|
|
|
|
|
|
gdb/17394: cannot put breakpoint only in selected ASM file.
This patch fixes a problem when trying to insert a breakpoint on
a specific symbol defined in a specific file, eg:
break foo.c:func
This currently works for files in C/C++/Ada, etc, but doesn't always
work for Asm files. Analysis of the problem showed that this related
to a limitation in gas, which does not generate debug info for functions/
symbols. Thus, we have a symtab for the file ("info sources" shows
the file), but it contains no symbols.
When find_linespec_symbols is called in linespec_parse_basic, it calls
find_function_symbols, which uses add_matching_symbols_to_info to
collect all matching symbols.
That function does [pardon any mangled formatting]:
for (ix = 0; VEC_iterate (symtab_ptr, info->file_symtabs, ix, elt); ++ix)
{
if (elt == NULL)
{
iterate_over_all_matching_symtabs (info->state, name, VAR_DOMAIN,
collect_symbols, info,
pspace, 1);
search_minsyms_for_name (info, name, pspace);
}
else if (pspace == NULL || pspace == SYMTAB_PSPACE (elt))
{
/* Program spaces that are executing startup should have
been filtered out earlier. */
gdb_assert (!SYMTAB_PSPACE (elt)->executing_startup);
set_current_program_space (SYMTAB_PSPACE (elt));
iterate_over_file_blocks (elt, name, VAR_DOMAIN,
collect_symbols, info);
}
}
This iterates over the symtabs. In the failing use case, ELT is
non-NULL (points to the symtab for the .s file), so it calls
iterate_over_file_blocks. Herein is where the problem exists: it is
assumed that if NAME exists, it must exist in the given symtab -- a
reasonable assumption for "normal" (non-asm) cases. It never searches
minimal symbols (or in the global default symtab).
This patch fixes the problem by doing so. It is important to note that
iterating over minsyms is fairly expensive, so this patch only adds
that extra search if the language is language_asm and
iterate_over_file_blocks returns no symbols.
gdb/ChangeLog:
2014-12-20 Keith Seitz <keiths@redhat.com>
Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* linespec.c (struct collect_minsyms): Add new member `symtab'.
(add_minsym): Handle cases where info.symtab is non-NULL.
(search_minsyms_for_name): Add new parameter `symtab'.
Handle limiting searches to a specific symtab.
(add_matching_symtabs_to_info): Search through minimal symbols
for language_asm files for which no new symbols are found.
gdb/testsuite/ChangeLog:
2014-12-20 Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* gdb.linespec/break-asm-file.c: New file.
* gdb.linespec/break-asm-file.exp: New file.
* gdb.linespec/break-asm-file0.s: New file.
* gdb.linespec/break-asm-file1.s: New file.
2014-12-21 00:04:44 +08:00
|
|
|
.byte 3 /* DW_LNS_advance_line */
|
|
|
|
|
.sleb128 1 /* ... to 8 */
|
|
|
|
|
|
|
|
|
|
.byte 1 /* DW_LNS_copy */
|
|
|
|
|
|
|
|
|
|
.byte 0 /* DW_LNE_set_address */
|
|
|
|
|
.uleb128 5
|
|
|
|
|
.byte 2
|
|
|
|
|
.4byte .Lend_func
|
|
|
|
|
|
|
|
|
|
.byte 0 /* DW_LNE_end_of_sequence */
|
|
|
|
|
.uleb128 1
|
|
|
|
|
.byte 1
|
|
|
|
|
|
|
|
|
|
.Lline1_end:
|
