Currently there are many prefix commands that do nothing but call
either help_list or cmd_show_list. I happened to notice that one such
call, for "set print type", used the wrong command list parameter,
causing incorrect output.
Rather than fix this bug in isolation, I decided to eliminate this
possibility by adding two new ways to add prefix commands, which
simply route the call to help_list or cmd_show_list, as appropriate.
This makes it impossible for a mismatch to occur.
In some cases, a bit of output was removed; however, I don't think
this output in general was very useful. It seemed redundant with
what's already printed by help_list. A representative example is this
hunk, removed from ada-lang.c:
- printf_unfiltered (_(\
-"\"set ada\" must be followed by the name of a setting.\n"));
This simplified the CLI style set/show commands quite a bit, and
allowed the deletion of a macro.
This also cleans up some unusual code in windows-tdep.c.
Tested on x86-64 Fedora 30. Note that I have no way to build the
go32-nat.c change.
gdb/ChangeLog
2020-04-17 Tom Tromey <tromey@adacore.com>
* auto-load.c (show_auto_load_cmd): Remove.
(auto_load_show_cmdlist_get): Use add_show_prefix_cmd.
* arc-tdep.c (_initialize_arc_tdep): Use add_show_prefix_cmd.
(maintenance_print_arc_command): Remove.
* tui/tui-win.c (tui_command): Remove.
(tui_get_cmd_list): Use add_basic_prefix_cmd.
* tui/tui-layout.c (tui_layout_command): Remove.
(_initialize_tui_layout): Use add_basic_prefix_cmd.
* python/python.c (user_set_python, user_show_python): Remove.
(_initialize_python): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* guile/guile.c (set_guile_command, show_guile_command): Remove.
(install_gdb_commands): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(info_guile_command): Remove.
* dwarf2/read.c (set_dwarf_cmd, show_dwarf_cmd): Remove.
(_initialize_dwarf2_read): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cli/cli-style.h (class cli_style_option) <add_setshow_commands>:
Remove do_set and do_show parameters.
* cli/cli-style.c (set_style, show_style): Remove.
(_initialize_cli_style): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(cli_style_option::add_setshow_commands): Remove do_set and
do_show parameters.
(cli_style_option::add_setshow_commands): Use
add_basic_prefix_cmd, add_show_prefix_cmd.
(STYLE_ADD_SETSHOW_COMMANDS): Remove macro.
(set_style_name): Remove.
* cli/cli-dump.c (dump_command, append_command): Remove.
(srec_dump_command, ihex_dump_command, verilog_dump_command)
(tekhex_dump_command, binary_dump_command)
(binary_append_command): Remove.
(_initialize_cli_dump): Use add_basic_prefix_cmd.
* windows-tdep.c (w32_prefix_command_valid): Remove global.
(init_w32_command_list): Remove; move into ...
(_initialize_windows_tdep): ... here. Use add_basic_prefix_cmd.
* valprint.c (set_print, show_print, set_print_raw)
(show_print_raw): Remove.
(_initialize_valprint): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* typeprint.c (set_print_type, show_print_type): Remove.
(_initialize_typeprint): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* record.c (set_record_command, show_record_command): Remove.
(_initialize_record): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cli/cli-cmds.c (_initialize_cli_cmds): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(info_command, show_command, set_debug, show_debug): Remove.
* top.h (set_history, show_history): Don't declare.
* top.c (set_history, show_history): Remove.
* target-descriptions.c (set_tdesc_cmd, show_tdesc_cmd)
(unset_tdesc_cmd): Remove.
(_initialize_target_descriptions): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* symtab.c (info_module_command): Remove.
(_initialize_symtab): Use add_basic_prefix_cmd.
* symfile.c (overlay_command): Remove.
(_initialize_symfile): Use add_basic_prefix_cmd.
* sparc64-tdep.c (info_adi_command): Remove.
(_initialize_sparc64_adi_tdep): Use add_basic_prefix_cmd.
* sh-tdep.c (show_sh_command, set_sh_command): Remove.
(_initialize_sh_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* serial.c (serial_set_cmd, serial_show_cmd): Remove.
(_initialize_serial): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* ser-tcp.c (set_tcp_cmd, show_tcp_cmd): Remove.
(_initialize_ser_tcp): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* rs6000-tdep.c (set_powerpc_command, show_powerpc_command)
(_initialize_rs6000_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* riscv-tdep.c (show_riscv_command, set_riscv_command)
(show_debug_riscv_command, set_debug_riscv_command): Remove.
(_initialize_riscv_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* remote.c (remote_command, set_remote_cmd): Remove.
(_initialize_remote): Use add_basic_prefix_cmd.
* record-full.c (set_record_full_command)
(show_record_full_command): Remove.
(_initialize_record_full): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* record-btrace.c (cmd_set_record_btrace)
(cmd_show_record_btrace, cmd_set_record_btrace_bts)
(cmd_show_record_btrace_bts, cmd_set_record_btrace_pt)
(cmd_show_record_btrace_pt): Remove.
(_initialize_record_btrace): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* ravenscar-thread.c (set_ravenscar_command)
(show_ravenscar_command): Remove.
(_initialize_ravenscar): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* mips-tdep.c (show_mips_command, set_mips_command)
(_initialize_mips_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* maint.c (maintenance_command, maintenance_info_command)
(maintenance_check_command, maintenance_print_command)
(maintenance_set_cmd, maintenance_show_cmd): Remove.
(_initialize_maint_cmds): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(show_per_command_cmd): Remove.
* maint-test-settings.c (maintenance_set_test_settings_cmd):
Remove.
(maintenance_show_test_settings_cmd): Remove.
(_initialize_maint_test_settings): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* maint-test-options.c (maintenance_test_options_command):
Remove.
(_initialize_maint_test_options): Use add_basic_prefix_cmd.
* macrocmd.c (macro_command): Remove
(_initialize_macrocmd): Use add_basic_prefix_cmd.
* language.c (set_check, show_check): Remove.
(_initialize_language): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* infcmd.c (unset_command): Remove.
(_initialize_infcmd): Use add_basic_prefix_cmd.
* i386-tdep.c (set_mpx_cmd, show_mpx_cmd): Remove.
(_initialize_i386_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* go32-nat.c (go32_info_dos_command): Remove.
(_initialize_go32_nat): Use add_basic_prefix_cmd.
* cli/cli-decode.c (do_prefix_cmd, add_basic_prefix_cmd)
(do_show_prefix_cmd, add_show_prefix_cmd): New functions.
* frame.c (set_backtrace_cmd, show_backtrace_cmd): Remove.
(_initialize_frame): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* dcache.c (set_dcache_command, show_dcache_command): Remove.
(_initialize_dcache): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cp-support.c (maint_cplus_command): Remove.
(_initialize_cp_support): Use add_basic_prefix_cmd.
* btrace.c (maint_btrace_cmd, maint_btrace_set_cmd)
(maint_btrace_show_cmd, maint_btrace_pt_set_cmd)
(maint_btrace_pt_show_cmd, _initialize_btrace): Use
add_basic_prefix_cmd, add_show_prefix_cmd.
* breakpoint.c (save_command): Remove.
(_initialize_breakpoint): Use add_basic_prefix_cmd.
* arm-tdep.c (set_arm_command, show_arm_command): Remove.
(_initialize_arm_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* ada-lang.c (maint_set_ada_cmd, maint_show_ada_cmd)
(set_ada_command, show_ada_command): Remove.
(_initialize_ada_language): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* command.h (add_basic_prefix_cmd, add_show_prefix_cmd): Declare.
gdb/testsuite/ChangeLog
2020-04-17 Tom Tromey <tromey@adacore.com>
* gdb.cp/maint.exp (test_help): Simplify multiple_help_body.
Update tests.
* gdb.btrace/cpu.exp: Update tests.
* gdb.base/maint.exp: Update tests.
* gdb.base/default.exp: Update tests.
* gdb.base/completion.exp: Update tests.
Consider the test-case added in this patch, with resulting dwarf:
...
Compilation Unit @ offset 0xc7:
Length: 0x2c (32-bit)
Version: 4
Abbrev Offset: 0x64
Pointer Size: 8
<0><d2>: Abbrev Number: 2 (DW_TAG_partial_unit)
<d3> DW_AT_language : 2 (non-ANSI C)
<d4> DW_AT_name : imported_unit.c
<1><e4>: Abbrev Number: 3 (DW_TAG_base_type)
<e5> DW_AT_byte_size : 4
<e6> DW_AT_encoding : 5 (signed)
<e7> DW_AT_name : int
<1><eb>: Abbrev Number: 4 (DW_TAG_subprogram)
<ec> DW_AT_name : main
<f1> DW_AT_type : <0xe4>
<f5> DW_AT_external : 1
<1><f6>: Abbrev Number: 0
Compilation Unit @ offset 0xf7:
Length: 0x2c (32-bit)
Version: 4
Abbrev Offset: 0x85
Pointer Size: 8
<0><102>: Abbrev Number: 2 (DW_TAG_compile_unit)
<103> DW_AT_language : 2 (non-ANSI C)
<104> DW_AT_name : <artificial>
<1><111>: Abbrev Number: 3 (DW_TAG_subprogram)
<112> DW_AT_abstract_origin: <0xeb>
<116> DW_AT_low_pc : 0x4004a7
<11e> DW_AT_high_pc : 0x4004b2
<1><126>: Abbrev Number: 0
...
When run with target board cc-with-gdb-index, we run into:
...
(gdb) break main
warning: (Internal error: pc 0x4004a7 in read in CU, but not in symtab.)
<repeat>
warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
<repeat>
Breakpoint 1 at 0x4004ab
(gdb) PASS: gdb.dwarf2/imported-unit-runto-main.exp: setting breakpoint at main
run
Starting program: /data/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.dwarf2/imported-unit-runto-main/imported-unit-runto-main
warning: (Internal error: pc 0x4004a7 in read in CU, but not in symtab.)
<repeat>
warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
<repeat>
Breakpoint 1, warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
<repeat>
0x00000000004004ab in main ()
warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
<repeat>
(gdb) FAIL: gdb.dwarf2/imported-unit-runto-main.exp: running to main in runto
...
Looking at the .gdb_index section contents using objdump --dwarf=gdb_index, we
have:
...
CU table:
[ 0] 0x0 - 0x2d
[ 1] 0x2e - 0xa4
[ 2] 0xa5 - 0xc6
[ 3] 0xf7 - 0x126
[ 4] 0x127 - 0x2de
[ 5] 0x2df - 0x300
Address table:
00000000004004a7 00000000004004b2 4
Symbol table:
[489] main: 4 [global, function]
...
We see that both the main symbol, and main address range map to CU 4, which has
offset range 0x127 - 0x2de, while main actually is contained in CU 3 at offset
range 0xf7 - 0x126.
This is caused by this continue in write_gdbindex, which triggers for the PU:
...
/* CU of a shared file from 'dwz -m' may be unused by this main file.
It may be referenced from a local scope but in such case it does not
need to be present in .gdb_index. */
if (psymtab == NULL)
continue;
...
The continue causes the PU to be skipped in the CU table (we can see that the
PU offset range 0xc7-0xf6 is missing) but the references are not taking that
into account.
I've tried fixing this in the optimal way, by updating the references, but ran
into trouble when follow_die_offset tries to find the CU for the inter-CU
ref. Because the PU is missing from the CU table,
dwarf2_find_containing_comp_unit bisects to the wrong CU.
Fix this by not skipping the PU in the CU table.
Build and reg-tested on x86_64-linux, with native and target boards
cc-with-gdb-index, cc-with-dwz and cc-with-dwz-m.
gdb/ChangeLog:
2020-04-16 Tom de Vries <tdevries@suse.de>
PR symtab/25791
* dwarf2/index-write.c (write_gdbindex): Generate CU table entries for
CUs without psymtab.
gdb/testsuite/ChangeLog:
2020-04-16 Tom de Vries <tdevries@suse.de>
PR symtab/25791
* gdb.dwarf2/gdb-add-index.exp (add_gdb_index): Move ...
(ensure_gdb_index): and factor out and move ...
* lib/gdb.exp (add_gdb_index, ensure_gdb_index): ... here.
* gdb.dwarf2/imported-unit-runto-main.exp: New file.
[ The test-case requires commit c1a66c0629 "[gdb] Expand symbolless symtabs
using maint expand-symtabs". ]
Consider the debug info for the test-case included in this patch. It consists
of a PU:
...
<0><d2>: Abbrev Number: 2 (DW_TAG_partial_unit)
<1><d3>: Abbrev Number: 0
...
imported by a CU:
...
<0><df>: Abbrev Number: 2 (DW_TAG_compile_unit)
<e0> DW_AT_language : 2 (non-ANSI C)
<e1> DW_AT_stmt_list : 0xe9
<1><e5>: Abbrev Number: 3 (DW_TAG_imported_unit)
<e6> DW_AT_import : <0xd2> [Abbrev Number: 2]
<1><ea>: Abbrev Number: 0
...
and the CU has a dw2-symtab-includes.h file in the .debug_line file name
table:
...
The Directory Table (offset 0x101):
1 /data/gdb_versions/devel/src/gdb/testsuite/gdb.dwarf2
The File Name Table (offset 0x138):
Entry Dir Time Size Name
1 1 0 0 dw2-symtab-includes.h
...
After expanding all symtabs, we can see the CU listed in the user field of the
PU, and vice-versa the PU listed in the includes of the CU:
...
$ gdb.sh -batch \
-iex "set language c" \
outputs/gdb.dwarf2/dw2-symtab-includes/dw2-symtab-includes \
-ex "maint expand-symtabs" \
-ex "maint info symtabs"
...
{ ((struct compunit_symtab *) 0x394dd60)
debugformat DWARF 2
producer (null)
dirname (null)
blockvector ((struct blockvector *) 0x394dea0)
user ((struct compunit_symtab *) 0x394dba0)
}
{ ((struct compunit_symtab *) 0x394dba0)
debugformat DWARF 2
producer (null)
dirname (null)
blockvector ((struct blockvector *) 0x394dd10)
user ((struct compunit_symtab *) (null))
( includes
((struct compunit_symtab *) 0x394dd60)
)
}
...
But if we instead only expand the symtab for the dw2-symtab-includes.h file,
the includes and user links are gone:
...
$ gdb -batch \
-iex "set language c" \
outputs/gdb.dwarf2/dw2-symtab-includes/dw2-symtab-includes \
-ex "maint expand-symtabs dw2-symtab-includes.h" \
-ex "maint info symtabs"
...
{ ((struct compunit_symtab *) 0x2728210)
debugformat DWARF 2
producer (null)
dirname (null)
blockvector ((struct blockvector *) 0x2728350)
user ((struct compunit_symtab *) (null))
}
{ ((struct compunit_symtab *) 0x2728050)
debugformat DWARF 2
producer (null)
dirname (null)
blockvector ((struct blockvector *) 0x27281c0)
user ((struct compunit_symtab *) (null))
}
...
The includes are calculated by process_cu_includes in gdb/dwarf2/read.c.
In the case of expanding all symtabs:
- the CU partial symtab is expanded using psymtab_to_symtab
- psymtab_to_symtab calls dwarf2_psymtab::read_symtab
- dwarf2_psymtab::read_symtab calls dwarf2_psymtab::expand_psymtab
- dwarf2_psymtab::read_symtab calls process_cu_includes, and we have the
includes
In the case of expanding the symtab for dw2-symtab-includes.h:
- the dw2-symtab-includes.h partial symtab is expanded using psymtab_to_symtab
- psymtab_to_symtab calls dwarf2_include_psymtab::read_symtab
- dwarf2_include_psymtab::read_symtab calls
dwarf2_include_psymtab::expand_psymtab
- dwarf2_include_psymtab::expand_psymtab calls
partial_symtab::expand_dependencies
- partial_symtab::expand_dependencies calls dwarf2_psymtab::expand_psymtab
for the CU partial symtab
- the CU partial symtab is expanded using dwarf2_psymtab::expand_psymtab
- process_cu_includes is never called
Fix this by making sure in dwarf2_include_psymtab::read_symtab that
read_symtab is called for the CU partial symtab.
Tested on x86_64-linux, with native, and target board cc-with-dwz and
cc-with-dwz-m.
In addition, tested test-case with target boards cc-with-gdb-index.exp,
cc-with-debug-names.exp and readnow.exp.
gdb/ChangeLog:
2020-04-14 Simon Marchi <simon.marchi@polymtl.ca>
Tom de Vries <tdevries@suse.de>
PR symtab/25718
* psympriv.h (struct partial_symtab::read_symtab)
(struct partial_symtab::expand_psymtab)
(struct partial_symtab::read_dependencies): Update comments.
* dwarf2/read.c (struct dwarf2_include_psymtab::read_symtab): Call
read_symtab for includer.
(struct dwarf2_include_psymtab::expand_psymtab): Assert false.
(struct dwarf2_include_psymtab::readin_p): Call readin_p () for includer.
(struct dwarf2_include_psymtab::m_readin): Remove.
(struct dwarf2_include_psymtab::includer): New member function.
(dwarf2_psymtab::expand_psymtab): Assert !readin.
gdb/testsuite/ChangeLog:
2020-04-14 Tom de Vries <tdevries@suse.de>
PR symtab/25718
* gdb.dwarf2/dw2-symtab-includes.exp: New file.
Consider this test-case, consisting of header file hello.h:
...
inline static const char*
foo (void)
{
return "foo";
}
...
and source file hello.c:
...
int
main (void)
{
printf ("hello: %s\n", foo ());
return 0;
}
...
compiled with -g:
...
$ gcc hello.c -g
...
When trying to expand the partial symtab for hello.h:
...
$ gdb -batch \
-iex "set language c" \
a.out \
-ex "maint expand-symtabs hello.h" \
-ex "maint info psymtabs"
...
we in fact find that the partial symtab for hello.h (and corresponding
includer partial symtab hello.c) have not been expanded:
...
{ psymtab hello.h ((struct partial_symtab *) 0x27cf070)
readin no
...
{ psymtab hello.c ((struct partial_symtab *) 0x2cf09e0)
readin no
...
This is due to the recursively_search_psymtabs call in
psym_expand_symtabs_matching:
...
if (recursively_search_psymtabs (ps, objfile, domain,
lookup_name, symbol_matcher))
...
which always returns false for symbolless partial symtabs.
The same problem occurs with CUs where the dwarf is generated by gas
--gdwarf-2 for a foo.S: if we read such a test-case with -readnow, we'll have
a symbolless symtab for foo.S. But if we read the test-case with partial
symtabs, and expand those using "maint expand-symtabs", the foo.S psymtab
remains unexpanded.
Fix this by passing a NULL symbol_matcher and lookup_name to
expand_symtabs_matching in maintenance_expand_symtabs, and skipping the call
to recursively_search_psymtabs if symbol_matcher == NULL and
lookup_name == NULL.
Build and tested on x86_64-linux, with native.
In addition, tested test-case with target boards cc-with-gdb-index.exp,
cc-with-debug-names.exp and readnow.exp.
gdb/ChangeLog:
2020-04-14 Tom de Vries <tdevries@suse.de>
PR symtab/25720
* symmisc.c (maintenance_expand_symtabs): Call expand_symtabs_matching
with NULL symbol_matcher and lookup_name.
* psymtab.c (psym_expand_symtabs_matching): Handle NULL symbol_matcher
and lookup_name.
* dwarf2/read.c (dw2_expand_symtabs_matching)
(dw2_debug_names_expand_symtabs_matching): Same.
* symfile.h (struct quick_symbol_functions::expand_symtabs_matching):
Make lookup_name a pointer. Update comment.
* symtab.c (global_symbol_searcher::expand_symtabs): Handle
lookup_name being a pointer.
* symfile.c (expand_symtabs_matching): Same.
* symfile-debug.c (debug_qf_expand_symtabs_matching): Same.
* linespec.c (iterate_over_all_matching_symtabs): Same.
gdb/testsuite/ChangeLog:
2020-04-14 Tom de Vries <tdevries@suse.de>
PR symtab/25720
* gdb.base/maint-expand-symbols-header-file.c: New test.
* gdb.base/maint-expand-symbols-header-file.exp: New file.
* gdb.base/maint-expand-symbols-header-file.h: New test.
I noticed this was unused, so remove it.
gdb/ChangeLog:
* dwarf2/read.c (read_gdb_index_from_buffer): Remove objfile
parameter.c.
(dwarf2_read_gdb_index): Update.
GDB throws the error 'Unrecognized DWARF opcode 0x02 at 2' when running
Info address command with the executable file compiled with -gdwarf-5 flag.
This patch fixes this error.
Tested by running the testsuite before and after the patch and there is
no increase in the number of test cases that fails. Tested with both
-gdwarf-4 and -gdwarf-5 flags. Also tested -gslit-dwarf along with
-gdwarf-4 as well as -gdwarf-5 flags. Used clang version 10.0.0.
This is the test case used-
void bar(int arr[], int l, int m, int r) {
int i, j, k, n1= m - l + 1, n2= r - m, L[n1], R[n2];
for (i = 0; i < n1; i++)
L[i] = arr[l + i];
for (j = 0; j < n2; j++)
R[j] = arr[m + 1+ j];
}
int main()
{
int arr[] = {12, 11};
bar(arr,0,1,2);
return 0;
}
clang -gdwarf-5 test.c -o test.out
gdb test.out
gdb> start
gdb> step
gdb> step
gdb> step
gdb> step
gdb> info address L
Symbol "L" is multi-location:
Range 0x7c04007902bc5084-0x67fb876440700: a complex DWARF expression:
0: DW_OP_breg16 1 [$rip]
Unrecognized DWARF opcode 0x02 at 2
gdb/ChangeLog:
2020-04-07 Nitika Achra <Nitika.Achra@amd.com>
* dwarf2/loc.c (loclist_describe_location): Call the function decode_debug_loclists_
addresses if DWARF version is 5 or more because DW_LLE_start* or DW_LLE_offset_pair
with DW_LLE_base_addressx are being emitted in DWARFv5.
Add the newly added kind DW_LOC_OFFSET_PAIR also.
The length of location description is an unsigned ULEB integer in DWARFv5 instead of
unsigned integer.
GDB throws the error '<error reading variable: dwarf2_find_location_
expression: Corrupted DWARF expression.>' while printing the variable
value with executable file compiled with -gdwarf-5 and -gdwarf-split
flags. This is because DW_LLE_start* or DW_LLE_offset_pair with
DW_LLE_base_addressx are being emitted in DWARFv5 location list instead of
DW_LLE_GNU*. This patch fixes this error.
Tested by running the testsuite before and after the patch and there is no
increase in the number of test cases that fails. Tested with both -gdwarf-4
and -gdwarf-5 flags. Also tested -gslit-dwarf along with -gdwarf-4 as well as
-gdwarf-5 flags. Used clang version 10.0.0. This is the test case used-
void bar(int arr[], int l, int m, int r) {
int i, j, k, n1= m - l + 1, n2= r - m, L[n1], R[n2];
for (i = 0; i < n1; i++)
L[i] = arr[l + i];
for (j = 0; j < n2; j++)
R[j] = arr[m + 1+ j];
}
int main()
{
int arr[] = {12, 11};
bar(arr,0,1,2);
return 0;
}
clang -gdwarf-5 -gsplit-dwarf test.c -o test.out
gdb test.out
gdb> start
gdb> step
gdb> step
gdb> step
gdb> step
gdb> p L[0]
dwarf2_find_location_expression: Corrupted DWARF expression.
gdb/ChangeLog:
2020-04-07 Nitika Achra <Nitika.Achra@amd.com>
* dwarf2/loc.c (enum debug_loc_kind): Add a new kind DEBUG_LOC_OFFSET_PAIR.
(dwarf2_find_location_expression): Call the function decode_debug_loclists_
addresses if DWARF version is 5 or more. DW_LLE_start* or DW_LLE_offset_pair
with DW_LLE_base_addressx are being emitted in DWARFv5 instead of DW_LLE_GNU*.
Add applicable base address if the entry is DW_LLE_offset_pair from DWO.
(decode_debug_loclists_addresses): Return DEBUG_LOC_OFFSET_PAIR instead of
DEBUG_LOC_START_END in case of DW_LLE_offset_pair.
I noticed that only one of the two dwarf2_psymtab constructors are
actually used. The one that is used accepts an `addr` parameter (the
base text offset), but its sole caller passes a constant, 0. We want to
keep calling the three-arguments standard_psymtab constructor form,
however, since it differs from the two-arguments form in subtle ways.
Also, I believe the dwarf2_per_cu_data associated to the created
dwarf2_psymtab should be passed as a constructor argument. That will
help me in a future patchset, to convince myself that the `per_cu_data`
field can't be NULL.
So this patch:
- Removes the two-parameters constructor of dwarf2_psymtab, as it is
unused.
- Removes the `addr` parameter of the remaining constructor, passing 0
directly to the base class' constructor.
- Adds a `per_cu` parameter, to assign the `per_cu_data` field at
construction.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_psymtab): Remove two-parameters
constructor. Remove `addr` parameter from other constructor and
add `per_cu` parameter.
* dwarf2/read.c (create_partial_symtab): Update.
Consider the test-case added in this patch, with resulting dwarf (related to
variable aaa):
...
<0><d2>: Abbrev Number: 2 (DW_TAG_partial_unit)
<1><eb>: Abbrev Number: 4 (DW_TAG_variable)
<ec> DW_AT_name : aaa
<f0> DW_AT_type : <0xe4>
<f4> DW_AT_const_value : 1
<0><10c>: Abbrev Number: 2 (DW_TAG_compile_unit)
<10e> DW_AT_name : <artificial>
<1><11b>: Abbrev Number: 3 (DW_TAG_variable)
<11c> DW_AT_abstract_origin: <0xeb>
...
When running the test-case, we see:
...
(gdb) p aaa^M
No symbol "aaa" in current context.^M
(gdb) FAIL: gdb.dwarf2/imported-unit-abstract-const-value.exp: p aaa
...
while with target board readnow.exp, we have:
...
(gdb) p aaa^M
$1 = 1^M
...
This is due to the fact that there's no aaa symbol in the partial symtabs:
...
Partial symtab for source file <artificial>@0x101 (object 0x351cf40)^M
...
Global partial symbols:^M
`main', function, 0x4004a7^M
^M
...
which is due to the fact that when attempting to add the symbol corresponding
to DIE 0x11b in add_partial_symbol:
...
(gdb) p /x pdi->sect_off
$4 = 0x11b
(gdb) p pdi.has_const_value
$5 = 0
...
it seems the DW_AT_const_value was not inherited from DIE 0xeb, and
consequently we leave without adding a partial symbol.
Fix this by making sure that partial_die_info::has_const_value is inherited
in partial_die_info::fixup.
Build and reg-tested on x86_64-linux.
Tested test-case with target boards readnow, cc-with-gdb-index and
cc-with-debug-names. The "print aaa" test fails for cc-with-gdb-index, that's
PR25791, the test passes when applying the corresponding proposed patch.
gdb/ChangeLog:
2020-04-07 Tom de Vries <tdevries@suse.de>
PR symtab/25796
* dwarf2/read.c (can_have_DW_AT_const_value_p): New function.
(partial_die_info::fixup): Inherit has_const_value.
gdb/testsuite/ChangeLog:
2020-04-07 Tom de Vries <tdevries@suse.de>
PR symtab/25796
* gdb.dwarf2/imported-unit-abstract-const-value.exp: New file.
It turns out there was one more bug in the earlier complex series:
read_base_type could cause an assertion failure on some platforms. I
found this running the AdaCore internal test suite, but you can also
see it by running gdb's "gdb.cp" tests for x86 (not x86-64).
In particular, the DW_ATE_complex_float case calls
dwarf2_init_complex_target_type, which calls dwarf2_init_float_type,
which can return a type using TYPE_CODE_ERROR.
This patch changes the DWARF reader to handle this case, the same way
that the f-lang.c patch did. Perhaps init_complex_type really should
be changed to allow TYPE_CODE_ERROR? I was not sure.
Tested on x86-64 Fedora 30, using an x86 build. I'm checking this in.
gdb/ChangeLog
2020-04-06 Tom Tromey <tromey@adacore.com>
* dwarf2/read.c (read_base_type) <DW_ATE_complex_float>: Handle
TYPE_CODE_ERROR.
For this enum:
typedef unsigned char byte;
enum byte_enum : byte
{
byte_val = 128
};
The unsigned attribute is not set:
(gdb) p byte_val
$1 = -128
That's because it uses the attributes of the 'byte' typedef for the enum.
So this changes it to use the attributes of the underlying 'unsigned char'
instead.
gdb/ChangeLog:
2020-04-03 Hannes Domani <ssbssa@yahoo.de>
PR gdb/25325
* dwarf2/read.c (read_enumeration_type): Fix typed enum attributes.
gdb/testsuite/ChangeLog:
2020-04-03 Hannes Domani <ssbssa@yahoo.de>
PR gdb/25325
* gdb.cp/typed-enum.cc: New test.
* gdb.cp/typed-enum.exp: New file.
While debugging another issue, I noticed that disassembling a DWARF
expression using DW_OP_const_type did not work.
disassemble_dwarf_expression was not properly decoding this operation.
This patch fixes the problem. Tested by re-debugging gdb.
I didn't write a test case because that seemed like overkill for
what's essentially a maintainer's helper.
The expression evaluator does decode this properly, so no other change
was needed.
gdb/ChangeLog
2020-04-03 Tom Tromey <tromey@adacore.com>
* dwarf2/loc.c (disassemble_dwarf_expression) <DW_OP_const_type>:
Read constant block.
While profiling the DWARF reader, I noticed that
partial_die_info::read creates a vector to store attributes. However,
the vector is not needed, as this code only processes a single
attribute at a time.
This patch removes the vector. On my machine, this improves the time
of "./gdb ./gdb" from 2.22 seconds to 1.92 seconds (mean times over 10
runs).
Note that the attribute is initialized by read_attribute, so it does
not need any special initialization. Avoiding this also improves
performance a bit.
Tested on x86-64 Fedora 30. I'm checking this in.
gdb/ChangeLog
2020-04-02 Tom Tromey <tromey@adacore.com>
* dwarf2/read.c (partial_die_info::read): Do not create a vector
of attributes.
When running test-case gdb.ada/access_to_packed_array we have:
...
(gdb) print pack.a^M
$1 = (0 => 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)^M
...
but with target board readnow.exp, we have instead:
...
(gdb) print pack.a^M
'pack.a' has unknown type; cast it to its declared type^M
...
The symbol is normally found by the map_matching_symbols call in
ada-lang.c:add_nonlocal_symbols:
...
for (objfile *objfile : current_program_space->objfiles ())
{
data.objfile = objfile;
objfile->sf->qf->map_matching_symbols (objfile, lookup_name,
domain, global, callback,
(is_wild_match
? NULL : compare_names));
...
which maps onto psym_map_matching_symbols.
Function psym_map_matching_symbols iterates over all the partial symtabs,
and:
- if not expanded, searches in the partial symtab:
- if not found, continues to the next
- if found, expands into full symtab
- searches in the full symtab
However, with -readnow the call maps onto dw2_map_matching_symbols instead,
which is unimplemented, and consequently no symbol is found.
Fix this by detecting -readnow in dw2_map_matching_symbols, and handling that
appropriately given that partial symtabs are not present, and full symtabs
are: iterate over all the symtabs and search them.
Tested on x86_64-linux, with native and target board -readnow.
This removes 217 FAILs with board -readnow.
gdb/ChangeLog:
2020-04-02 Tom de Vries <tdevries@suse.de>
PR ada/24671
* dwarf2/read.c (dw2_map_matching_symbols): Handle -readnow.
When language is set to auto, part of loading an executable is to update the
language accordingly. This is implemented by set_initial_language.
The implementation of set_initial_language works as follows:
- check if any objfile in the progspace has name_of_main/language_of_main
set, and if so, use the first one found. [ This is what you get f.i. when
using dwarf with DW_AT_main_subprogram. ]
- otherwise, check for known names in the minimal symbols, and either:
- use the associated language if any (f.i. for ada), or
- lookup the symbol in the symtab for the name and use the symbol language
(f.i. for c/c++).
The symbol lookup can be slow though.
In the case of the cc1 binary from PR23710 comment 1, getting to the initial
prompt takes ~8s:
...
$ time.sh gdb cc1 -batch -ex "show language"
The current source language is "auto; currently c++".
maxmem: 1272260
real: 8.05
user: 7.73
system: 0.38
...
but if we skip guessing the initial language by setting it instead, it takes
only ~4s:
...
$ time.sh gdb -iex "set language c++" cc1 -batch -ex "show language"
The current source language is "c++".
maxmem: 498272
real: 3.99
user: 3.90
system: 0.15
...
In both cases, we load the partial symbols for the executable, but in the
first case only we also do a lookup of main, which causes the corresponding
partial symtab to be expanded into a full symtab.
Ideally, we'd like to get the language of the symbol without triggering
expansion into a full symtab, and get the speedup without having to set the
language manually.
There's a related fixme in the header comment of set_initial_language:
...
/* Set the initial language.
FIXME: A better solution would be to record the language in the
psymtab when reading partial symbols, and then use it (if known) to
set the language. This would be a win for formats that encode the
language in an easily discoverable place, such as DWARF. For
stabs, we can jump through hoops looking for specially named
symbols or try to intuit the language from the specific type of
stabs we find, but we can't do that until later when we read in
full symbols. */
void
set_initial_language (void)
...
Since we're already tracking the language of partial symbols, use this to set
the language for the main symbol.
Note that this search in partial symbol tables is not guaranteed to yield the
same result as the lookup_symbol_in_language call currently done in
set_initial_language.
Build and reg-tested on x86_64-linux.
gdb/ChangeLog:
2020-04-02 Tom de Vries <tdevries@suse.de>
* dwarf2/read.c (dwarf2_gdb_index_functions,
dwarf2_debug_names_functions): Init lookup_global_symbol_language with
NULL.
* psymtab.c (psym_lookup_global_symbol_language): New function.
(psym_functions): Init psym_lookup_global_symbol_language with
psym_lookup_global_symbol_language.
* symfile-debug.c (debug_sym_quick_functions): Init
lookup_global_symbol_language with NULL.
* symfile.c (set_initial_language): Remove fixme comment.
* symfile.h (struct quick_symbol_functions): Add
lookup_global_symbol_language.
* symtab.c (find_quick_global_symbol_language): New function.
(find_main_name): Use find_quick_global_symbol_language.
gdb/testsuite/ChangeLog:
2020-04-02 Tom de Vries <tdevries@suse.de>
* gdb.base/main-psymtab.exp: New file.
This patch changes how complex types are created. init_complex_type
and arch_complex_type are unified, and complex types are reused, by
attaching them to the underlying scalar type.
gdb/ChangeLog
2020-04-01 Tom Tromey <tom@tromey.com>
* stabsread.c (rs6000_builtin_type, read_sun_floating_type)
(read_range_type): Update.
* mdebugread.c (basic_type): Update.
* go-lang.c (build_go_types): Use init_complex_type.
* gdbtypes.h (struct main_type) <complex_type>: New member.
(init_complex_type): Update.
(arch_complex_type): Don't declare.
* gdbtypes.c (init_complex_type): Remove "objfile" parameter.
Make name if none given. Use alloc_type_copy. Look for cached
complex type.
(arch_complex_type): Remove.
(gdbtypes_post_init): Use init_complex_type.
* f-lang.c (build_fortran_types): Use init_complex_type.
* dwarf2/read.c (read_base_type): Update.
* d-lang.c (build_d_types): Use init_complex_type.
* ctfread.c (read_base_type): Update.
lookup_name_info always copies the name that is passed in. However,
normally a copy is not needed. This patch changes this class to avoid
copying. This required changing the "name" method to return something
else; I chose a gdb::string_view, to avoid excessive calls to strlen
in the code using the lookup_name_info. However, as this class does
not allow an arbitrary string_view, I've also added a c_str method
that guarantees a \0-terminated result -- a pedantic difference but
one that respects the string_view contract, IMO.
gdb/ChangeLog
2020-04-01 Tom Tromey <tromey@adacore.com>
* symtab.h (class lookup_name_info) <lookup_name_info>: Change
"name" parameter to rvalue reference. Initialize m_name_holder.
<lookup_name_info>: New overloads.
<name>: Return gdb::string_view.
<c_str>: New method.
<make_ignore_params>: Update.
<search_name_hash>: Update.
<language_lookup_name>: Return const char *.
<m_name>: Change type.
* symtab.c (demangle_for_lookup_info::demangle_for_lookup_info)
(demangle_for_lookup_info::demangle_for_lookup_info): Update.
(lookup_name_info::match_any): Update.
* psymtab.c (match_partial_symbol, lookup_partial_symbol):
Update.
* minsyms.c (linkage_name_str): Update.
* language.c (default_symbol_name_matcher): Update.
* dwarf2/read.c (mapped_index_base::find_name_components_bounds):
Update.
* ada-lang.c (ada_fold_name): Change parameter to string_view.
(ada_lookup_name_info::ada_lookup_name_info): Update.
(literal_symbol_name_matcher): Update.
I compiled gdb with -fsanitize=undefined and ran the test suite.
A couple of reports came from passing NULL to memcpy, e.g.:
[...]btrace-common.cc:176:13: runtime error: null pointer passed as argument 2, which is declared to never be null
While it would be better to fix this in the standard, in the meantime
it seems easy to avoid this error.
gdb/ChangeLog
2020-03-31 Tom Tromey <tromey@adacore.com>
* dwarf2/abbrev.c (abbrev_table::read): Conditionally call
memcpy.
gdbsupport/ChangeLog
2020-03-31 Tom Tromey <tromey@adacore.com>
* btrace-common.cc (btrace_data_append): Conditionally call
memcpy.
This method calls partial_symtab::expand_psymtab on all dependencies of
a psymtab. Given that there is also a partial_symtab::read_symtab
method, I think it would be clearer to name this function
expand_dependencies, rather than read_dependencies.
gdb/ChangeLog:
* psympriv.h (partial_symtab) <read_dependencies>: Rename to...
<expand_dependencies>: ... this.
* psymtab.c (partial_symtab::read_dependencies): Rename to...
(partial_symtab::expand_dependencies): ... this.
* dwarf2/read.c (dwarf2_include_psymtab) <expand_psymtab>:
Update.
(dwarf2_psymtab::expand_psymtab): Update.
* dbxread.c (dbx_psymtab_to_symtab_1): Update.
* mdebugread.c (psymtab_to_symtab_1): Update.
* xcoffread.c (xcoff_psymtab_to_symtab_1): Update.
I noticed that a comment in dwarf2/attribute.h still referred to
dwarf2_get_attr_constant_value. However, this is now a method on
struct attribute.
gdb/ChangeLog
2020-03-28 Tom Tromey <tom@tromey.com>
* dwarf2/attribute.h (struct attribute) <form_is_constant>: Update
comment.
I noticed that the start of read_attribute_reprocess had the wrong
formatting. This patch fixes it.
gdb/ChangeLog
2020-03-28 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (read_attribute_reprocess): Fix formatting.
This changes dwarf2_get_ref_die_offset and
dwarf2_get_attr_constant_value to be methods on struct attribute.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (handle_data_member_location, dwarf2_add_field)
(mark_common_block_symbol_computed, read_tag_string_type)
(attr_to_dynamic_prop, read_subrange_type): Update.
(dwarf2_get_ref_die_offset, dwarf2_get_attr_constant_value): Move
to be methods on struct attribute.
(skip_one_die, process_imported_unit_die, read_namespace_alias)
(read_call_site_scope, partial_die_info::read)
(partial_die_info::read, lookup_die_type, follow_die_ref):
Update.
* dwarf2/attribute.c (attribute::get_ref_die_offset): New method,
from dwarf2_get_ref_die_offset.
(attribute::constant_value): New method, from
dwarf2_get_attr_constant_value.
* dwarf2/attribute.h (struct attribute) <get_ref_die_offset>:
Declare method.
<constant_value>: New method.
This moves the DWARF debugging functions that stringify various
constants to a new file, dwarf2/stringify.c.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (dwarf_unit_type_name, dwarf_tag_name)
(dwarf_attr_name, dwarf_form_name, dwarf_bool_name)
(dwarf_type_encoding_name): Move to stringify.c.
* Makefile.in (COMMON_SFILES): Add dwarf2/stringify.c.
* dwarf2/stringify.c: New file.
* dwarf2/stringify.h: New file.
This rewrites the two new die_info methods to iterate over attributes
rather than to do two separate searches.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/die.h (struct die_info) <addr_base, ranges_base>:
Rewrite.
This changes lookup_addr_base and lookup_ranges_base to be methods on
die_info.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/die.h (struct die_info) <addr_base, ranges_base>: New
methods.
* dwarf2/read.c (lookup_addr_base): Move to die.h.
(lookup_ranges_base): Likewise.
(read_cutu_die_from_dwo, read_full_die_1): Update.
The sibling_die helper function does not seem to add much value,
considering that many other fields of die_info are directly accessed.
So, this removes it.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (read_import_statement, read_file_scope)
(read_type_unit_scope, inherit_abstract_dies, read_func_scope)
(read_lexical_block_scope, read_call_site_scope)
(dwarf2_get_subprogram_pc_bounds, get_scope_pc_bounds)
(handle_struct_member_die, process_structure_scope)
(update_enumeration_type_from_children)
(process_enumeration_scope, read_array_type, read_common_block)
(read_namespace, read_module, read_subroutine_type): Update.
(sibling_die): Remove.
This changes dwarf2_attr_no_follow to be a method on die_info.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (lookup_addr_base, lookup_ranges_base)
(build_type_psymtabs_reader, read_structure_type)
(read_enumeration_type, read_full_die_1): Update.
(dwarf2_attr_no_follow): Move to die.h.
* dwarf2/die.h (struct die_info) <attr>: New method.
This removes dwarf2_cu::base_known, changing base_address to be a
gdb::optional.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (struct dwarf2_cu) <base_known>: Remove.
<base_address>: Now an optional.
(dwarf2_find_base_address, dwarf2_rnglists_process)
(dwarf2_ranges_process, fill_in_loclist_baton)
(dwarf2_symbol_mark_computed): Update.
This moves struct die_info to a new header, dwarf2/die.h.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (struct die_info): Move to die.h.
* dwarf2/die.h: New file.
This moves some more code out of read.c and into line-header.c.
dwarf_decode_line_header is split into two -- the part remaining in
read.c handles interfacing to the dwarf2_cu; while the part in
line-header.c (more or less) purely handles the actual decoding.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/line-header.h (dwarf_decode_line_header): Declare.
* dwarf2/read.c
(dwarf2_statement_list_fits_in_line_number_section_complaint):
Move to line-header.c.
(read_checked_initial_length_and_offset, read_formatted_entries):
Likewise.
(dwarf_decode_line_header): Split into two.
* dwarf2/line-header.c
(dwarf2_statement_list_fits_in_line_number_section_complaint):
Move from read.c.
(read_checked_initial_length_and_offset, read_formatted_entries):
Likewise.
(dwarf_decode_line_header): New function, split from read.c.
This changes read_indirect_line_string to be a method on
dwarf2_per_objfile. This makes it a bit simpler to share between
files.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_per_objfile) <read_line_string>:
Declare method.
* dwarf2/read.c (read_attribute_value): Update.
(dwarf2_per_objfile::read_line_string): Rename from
read_indirect_line_string.
(read_formatted_entries): Update.
One spot in dwarf_decode_macro_bytes could use the existing "objfile"
local variable.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/macro.c (dwarf_decode_macro_bytes): Use objfile local
variable.
This changes the DWARF macro reader to use a const dwarf2_section_info.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/macro.h (dwarf_decode_macros): Make section parameter
const.
* dwarf2/macro.c (skip_form_bytes, skip_unknown_opcode)
(dwarf_decode_macro_bytes, dwarf_decode_macros): Make section
parameter const.
This changes a few line_header methods to be const. In some cases, a
const overload is added.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/line-header.h (struct line_header) <is_valid_file_index,
file_names_size, file_full_name, file_file_name>: Use const.
<file_name_at, file_names>: Add const overload.
* dwarf2/line-header.c (line_header::file_file_name)
(line_header::file_full_name): Update.
This moves some more code out of dwarf2/read.c, introducing new files
dwarf2/macro.c and dwarf2/macro.h.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (dwarf2_macro_malformed_definition_complaint)
(macro_start_file, consume_improper_spaces)
(parse_macro_definition, skip_form_bytes, skip_unknown_opcode)
(dwarf_parse_macro_header, dwarf_decode_macro_bytes)
(dwarf_decode_macros): Move to macro.c.
* dwarf2/macro.c: New file.
* dwarf2/macro.h: New file.
* Makefile.in (COMMON_SFILES): Add dwarf2/macro.c.
This moves a string-reading function to be a method on
dwarf2_section_info, and then updates the users.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/section.h (struct dwarf2_section_info) <read_string>: New
method.
* dwarf2/section.c: New method. From
read_indirect_string_at_offset_from.
* dwarf2/read.c (mapped_debug_names::namei_to_name): Update.
(read_indirect_string_at_offset_from): Move to section.c.
(read_indirect_string_at_offset): Rewrite.
(read_indirect_line_string_at_offset): Remove.
(read_indirect_string, read_indirect_line_string)
(dwarf_decode_macro_bytes): Update.
This splits dwarf_decode_macros into two overloads -- one that's
suitable for splitting into a separate file, and one that finds the
correct section and should remain in dwarf2/read.c.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (dwarf_decode_macros): Split into two overloads.
This changes dwarf_decode_macro_bytes to accept a buildsym_compunit
rather than a dwarf2_cu. This enables some subsequent changes; and
also makes the function accept a "more specific" parameter.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (macro_start_file): Change "cu" parameter to
"builder".
(dwarf_decode_macro_bytes): Likewise. Add dwarf2_per_objfile
parameter.
(dwarf_decode_macros): Update.
This changes read_indirect_string_from_dwz to be a method on the
dwz_file, and adds a new dwarf2/dwz.c file.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (read_attribute_value): Update.
(read_indirect_string_from_dwz): Move to dwz.c; change into
method.
(dwarf_decode_macro_bytes): Update.
* dwarf2/dwz.h (struct dwz_file) <read_string>: Declare method.
* dwarf2/dwz.c: New file.
* Makefile.in (COMMON_SFILES): Add dwz.c.
dwarf2_evaluate_property should not modify its "addr_stack"
parameter's contents. This patch makes this part of the API, by
marking it const.
gdb/ChangeLog
2020-03-20 Tom Tromey <tromey@adacore.com>
* dwarf2/loc.h (dwarf2_evaluate_property): Make "addr_stack"
const.
* dwarf2/loc.c (dwarf2_evaluate_property): Make "addr_stack"
const.
The DWARF standard appendix E.1 describes techniques that can be used for
compression and deduplication: DIEs can be factored out into a new compilation
unit, and referenced using DW_FORM_ref_addr.
Such a new compilation unit can either use a DW_TAG_compile_unit or
DW_TAG_partial_unit. If a DW_TAG_compile_unit is used, its contents is
evaluated by consumers as though it were an ordinary compilation unit. If a
DW_TAG_partial_unit is used, it's only considered by consumers in the context
of a DW_TAG_imported_unit.
An example of when DW_TAG_partial_unit is required is when the factored out
DIEs are not top-level, f.i. because they were children of a namespace. In
such a case the corresponding DW_TAG_imported_unit will occur as child of the
namespace.
In the case of factoring out DIEs from c++ compilation units, we can factor
out into a new DW_TAG_compile_unit, and no DW_TAG_imported_unit is required.
This begs the question how to interpret a top-level DW_TAG_imported_unit of a
c++ DW_TAG_compile_unit compilation unit. The semantics of
DW_TAG_imported_unit describe that the imported unit logically appears at the
point of the DW_TAG_imported_unit entry. But it's not clear what the effect
should be in this case, since all the imported DIEs are already globally
visible anyway, due to the use of DW_TAG_compile_unit.
So, skip top-level imports of c++ DW_TAG_compile_unit compilation units in
process_imported_unit_die.
Using the cc1 binary from PR23710 comment 1 and setting a breakpoint on do_rpo_vn:
...
$ gdb \
-batch \
-iex "maint set dwarf max-cache-age 316" \
-iex "set language c++" \
-ex "b do_rpo_vn" \
cc1
...
we get a 8.1% reduction in execution time, due to reducing the number of
partial symtabs expanded into full symtabs from 212 to 175.
Build and reg-tested on x86_64-linux.
gdb/ChangeLog:
2020-03-17 Tom de Vries <tdevries@suse.de>
PR gdb/23710
* dwarf2/read.h (struct dwarf2_per_cu_data): Add unit_type and lang
fields.
* dwarf2/read.c (process_psymtab_comp_unit): Initialize unit_type and lang
fields.
(process_imported_unit_die): Skip import of c++ CUs.
PR gdb/25663 points out that dwarf2_name will cache a value in the
bcache and then return a substring. However, this substring return is
only done on the branch that caches the value -- so if the function is
called twice with the same arguments, it will return different values.
This patch fixes this problem.
This area is strange. We cache the entire demangled string, but only
return the suffix. I looked at caching just the suffix, but it turns
out that anonymous_struct_prefix assumes that the entire string is
stored. Also weird is that this code is demangling the linkage name
and then storing the demangled form back into the linkage name
attribute -- that seems bad, because what if some code wants to find
the actual linkage name?
Fixing these issues was non-trivial, though; and in the meantime this
patch seems like an improvement. Regression tested on x86-64
Fedora 30.
gdb/ChangeLog
2020-03-16 Tom Tromey <tromey@adacore.com>
PR gdb/25663:
* dwarf2/read.c (dwarf2_name): Strip leading namespaces after
putting value into bcache.
When using the executable from test-case gdb.ada/access_to_packed_array.exp
(read-in using -readnow) and printing the symbols using "maint print symbols",
we run into a segv:
...
$ gdb -readnow -batch access_to_packed_array/foo -ex "maint print symbols"
...
info: array (<>) of character; computed at runtime
ptr: range 0 .. 2147483647; computed at runtime
Aborted (core dumped)
...
What happens is that dwarf2_evaluate_property gets called and sets the local
frame variable to the current frame, which happens to be NULL. Subsequently
the PROP_LOCLIST handling code is executed, where get_frame_address_in_block
gets called with argument NULL, and the segv is triggered.
Fix this by handling a NULL frame in the PROP_LOCLIST handling code in
dwarf2_evaluate_property.
Build and reg-tested on x86_64-linux.
gdb/ChangeLog:
2020-03-11 Tom de Vries <tdevries@suse.de>
* dwarf2/loc.c (dwarf2_evaluate_property): Handle NULL frame in
PROP_LOCLIST handling code.
gdb/testsuite/ChangeLog:
2020-03-11 Tom de Vries <tdevries@suse.de>
* gdb.ada/access_to_packed_array.exp: Test printing of expanded
symtabs.
This commit brings support for the DWARF line table is_stmt field to
GDB. The is_stmt field is used by the compiler when a single source
line is split into multiple assembler instructions, especially if the
assembler instructions are interleaved with instruction from other
source lines.
The compiler will set the is_stmt flag false from some instructions
from the source lines, these instructions are not a good place to
insert a breakpoint in order to stop at the source line.
Instructions which are marked with the is_stmt flag true are a good
place to insert a breakpoint for that source line.
Currently GDB ignores all instructions for which is_stmt is false.
This is fine in a lot of cases, however, there are some cases where
this means the debug experience is not as good as it could be.
Consider stopping at a random instruction, currently this instruction
will be attributed to the last line table entry before this point for
which is_stmt was true - as these are the only line table entries that
GDB tracks. This can easily be incorrect in code with even a low
level of optimisation.
With is_stmt tracking in place, when stopping at a random instruction
we now attribute the instruction back to the real source line, even
when is_stmt is false for that instruction in the line table.
When inserting breakpoints we still select line table entries for
which is_stmt is true, so the breakpoint placing behaviour should not
change.
When stepping though code (at the line level, not the instruction
level) we will still stop at instruction where is_stmt is true, I
think this is more likely to be the desired behaviour.
Instruction stepping is, of course, unchanged, stepping one
instruction at a time, but we should now report more accurate line
table information with each instruction step.
The original motivation for this work was a patch posted by Bernd
here:
https://sourceware.org/ml/gdb-patches/2019-11/msg00792.html
As part of that thread it was suggested that many issues would be
resolved if GDB supported line table views, this isn't something I've
attempted in this patch, though reading the spec, it seems like this
would be a useful feature to support in GDB in the future. The spec
is here:
http://dwarfstd.org/ShowIssue.php?issue=170427.1
And Bernd gives a brief description of the benefits here:
https://sourceware.org/ml/gdb-patches/2020-01/msg00147.html
With that all said, I think that there is benefit to having proper
is_stmt support regardless of whether we have views support, so I
think we should consider getting this in first, and then building view
support on top of this.
The gdb.cp/step-and-next-inline.exp test is based off a test proposed
by Bernd Edlinger in this message:
https://sourceware.org/ml/gdb-patches/2019-12/msg00842.html
gdb/ChangeLog:
* buildsym-legacy.c (record_line): Pass extra parameter to
record_line.
* buildsym.c (buildsym_compunit::record_line): Take an extra
parameter, reduce duplication in the line table, and record the
is_stmt flag in the line table.
* buildsym.h (buildsym_compunit::record_line): Add extra
parameter.
* disasm.c (do_mixed_source_and_assembly_deprecated): Ignore
non-statement lines.
* dwarf2/read.c (dwarf_record_line_1): Add extra parameter, pass
this to the symtab builder.
(dwarf_finish_line): Pass extra parameter to dwarf_record_line_1.
(lnp_state_machine::record_line): Pass a suitable is_stmt flag
through to dwarf_record_line_1.
* infrun.c (process_event_stop_test): When stepping, don't stop at
a non-statement instruction, and only refresh the step info when
we land in the middle of a line's range. Also add an extra
comment.
* jit.c (jit_symtab_line_mapping_add_impl): Initialise is_stmt
field.
* record-btrace.c (btrace_find_line_range): Only record lines
marked as is-statement.
* stack.c (frame_show_address): Show the frame address if we are
in a non-statement sal.
* symmisc.c (dump_symtab_1): Print the is_stmt flag.
(maintenance_print_one_line_table): Print a header for the is_stmt
column, and include is_stmt information in the output.
* symtab.c (find_pc_sect_line): Find lines marked as statements in
preference to non-statements.
(find_pcs_for_symtab_line): Prefer is-statement entries.
(find_line_common): Likewise.
* symtab.h (struct linetable_entry): Add is_stmt field.
(struct symtab_and_line): Likewise.
* xcoffread.c (arrange_linetable): Initialise is_stmt field when
arranging the line table.
gdb/testsuite/ChangeLog:
* gdb.cp/step-and-next-inline.cc: New file.
* gdb.cp/step-and-next-inline.exp: New file.
* gdb.cp/step-and-next-inline.h: New file.
* gdb.dwarf2/dw2-is-stmt.c: New file.
* gdb.dwarf2/dw2-is-stmt.exp: New file.
* gdb.dwarf2/dw2-is-stmt-2.c: New file.
* gdb.dwarf2/dw2-is-stmt-2.exp: New file.
* gdb.dwarf2/dw2-ranges-base.exp: Update line table pattern.
