This changes some spots in infcmd.c to use common_val_print (which,
despite its name, is a value-based API) rather than val_print.
gdb/ChangeLog
2020-03-13 Tom Tromey <tom@tromey.com>
* infcmd.c (default_print_one_register_info): Use
common_val_print.
A (much) later patch will remove the call to value_check_printable
from common_val_print. This will needed to preserve some details of
how optimized-out structures are printed.
However, doing this will also break dw2-op-out-param.exp. Making the
change causes "bt" to print:
However, the test wants to see:
... operand2=<optimized out>
That is, a wholly-optimized out structure should not print its fields.
So, this patch introduces a new common_val_print_checked, which calls
value_check_printable first, and then arranges to use it in the one
spot that affects the test suite.
I was not completely sure if it would be preferable to change the
test. However, I reasoned that, assuming this output was intentional
in the first place, in a backtrace space is at a premium and so this
is a reasonable approach. In other spots calling common_val_print,
this behavior is probably unintended, or at least a "don't care".
gdb/ChangeLog
2020-03-13 Tom Tromey <tom@tromey.com>
* valprint.h (common_val_print_checked): Declare.
* valprint.c (common_val_print_checked): New function.
* stack.c (print_frame_arg): Use common_val_print_checked.
This changes val_print and common_val_print to use a new helper
function. A theme in the coming patches is that calls to val_print
itself should be removed. This is the first such patch; at the end of
the series, we'll remove val_print and simplify do_val_print.
gdb/ChangeLog
2020-03-13 Tom Tromey <tom@tromey.com>
* valprint.c (do_val_print): New function, from val_print.
(val_print): Use do_val_print.
(common_val_print): Use do_val_print.
Switching the low-level printing to use the value API means we will be
using more temporary values. This adds a scoped_value_mark to
value_print, so that these intermediates are destroyed in a timely
way.
gdb/ChangeLog
2020-03-13 Tom Tromey <tom@tromey.com>
* valprint.c (value_print): Use scoped_value_mark.
Consider test-case gdb.dwarf2/imported-unit.exp.
It contains a CU with type int:
...
<0><129>: Abbrev Number: 2 (DW_TAG_compile_unit)
<12a> DW_AT_language : 4 (C++)
<12b> DW_AT_name : imported_unit.c
<1><13b>: Abbrev Number: 3 (DW_TAG_base_type)
<13c> DW_AT_byte_size : 4
<13d> DW_AT_encoding : 5 (signed)
<13e> DW_AT_name : int
...
which is imported in another CU:
...
<0><d2>: Abbrev Number: 2 (DW_TAG_compile_unit)
<d3> DW_AT_language : 4 (C++)
<d4> DW_AT_name : <artificial>
<1><e1>: Abbrev Number: 3 (DW_TAG_imported_unit)
<e2> DW_AT_import : <0x129> [Abbrev Number: 2]
...
However, if we print the partial symbols:
...
$ gdb -batch imported-unit -ex "maint print psymbols"
...
we see type int both in the importing CU:
...
Partial symtab for source file <artificial>@0xc7 (object 0x29f9b80)
...
Depends on 1 other partial symtabs.
0 0x2a24240 imported_unit.c
Global partial symbols:
`main', function, 0x4004b2
Static partial symbols:
`int', type, 0x0
...
and in the imported CU:
...
Partial symtab for source file imported_unit.c (object 0x2a24240)
...
Depends on 0 other partial symtabs.
Shared partial symtab with user 0x29f9b80
Static partial symbols:
`int', type, 0x0
...
This is an artefact resulting from the fact that all CUs in an objfile
share the same storage array for static partial symbols (and another array for
global partial symbols), using a range to describe their symbols.
Then when scanning the partial symbols of a CU and encountering an import, either:
- the referred CU has not been parsed yet, and will be parsed, and the range of
static partial symbols of the referred CU will be a subrange of the range of
static partial symbols of this CU, or
- the referred CU has already been parsed, and the range of static partial
symbols of the referred CU will not be a subrange of the range of static
partial symbols of this CU.
This is inconsistent handling, and confuses the notion of a symbol belonging to
a single symtab.
Furthermore, it might slow down searches, given that the symbol needs to be
skipped twice.
Finally, the same issue holds for global partial symbols, where the range of a
CU is sorted after parsing is finished. Obviously sorting the range of a CU
may invalidate subranges, effectively moving symbols in and out of imported
CUs.
Fix this for both static and global partial symbols, by gathering partial
symbols in a per-CU vector, and adding those symbols to the per-objfile
storage only once complete.
Tested on x86_64-linux, with native and board cc-with-dwz and cc-with-dwz-m.
gdb/ChangeLog:
2020-03-13 Tom de Vries <tdevries@suse.de>
PR symtab/25646
* psymtab.c (partial_symtab::partial_symtab): Don't set
globals_offset and statics_offset. Push element onto
current_global_psymbols and current_static_psymbols stacks.
(concat): New function.
(end_psymtab_common): Set globals_offset and statics_offset. Pop
element from current_global_psymbols and current_static_psymbols
stacks. Concat popped elements to global_psymbols and
static_symbols.
(add_psymbol_to_list): Use current_global_psymbols and
current_static_psymbols stacks.
* psymtab.h (class psymtab_storage): Add current_global_psymbols and
current_static_psymbols fields.
gdb/testsuite/ChangeLog:
2020-03-13 Tom de Vries <tdevries@suse.de>
PR symtab/25646
* gdb.dwarf2/imported-unit.exp: Add test.
There are no more callers to deprecated_add_core_fns, now that I have
removed the usage from CRIS and ARM/NetBSD. So this patch cleans up
all the related code and makes corelow.c a lot more readable.
gdb/ChangeLog:
2020-03-12 Christian Biesinger <cbiesinger@google.com>
* corelow.c (sniff_core_bfd): Remove.
(class core_target) <m_core_vec>: Remove.
(core_target::core_target): Update.
(core_file_fns): Remove.
(deprecated_add_core_fns): Remove.
(default_core_sniffer): Remove.
(sniff_core_bfd): Remove.
(default_check_format): Remove.
(gdb_check_format): Remove.
(core_target_open): Update.
(core_target::get_core_register_section): Update.
(get_core_registers_cb): Update.
(core_target::fetch_registers): Update.
* gdbcore.h (struct core_fns): Remove.
(deprecated_add_core_fns): Remove.
(default_core_sniffer): Remove.
(default_check_format): Remove.
Some arm-tdep.c data structures use a bfd_vma. A couple of spots will
warn about an implicit narrowing cast when building a gdb where
CORE_ADDR is 64-bit but bfd_vma is 32-bit.
This patch silences these warnings by changing the types in question
to CORE_ADDR.
gdb/ChangeLog
2020-03-12 Tom Tromey <tom@tromey.com>
* arm-tdep.c (struct arm_mapping_symbol) <value>: Now a
CORE_ADDR.
(struct arm_exidx_entry) <addr>: Now a CORE_ADDR.
A few spots in gdb use sprintf_vma to print a CORE_ADDR. This will
fail on a 32-bit build once CORE_ADDR is always a 64-bit type.
This patch replaces these calls with phex instead.
gdb/ChangeLog
2020-03-12 Tom Tromey <tom@tromey.com>
* remote.c (remote_target::download_tracepoint)
(remote_target::enable_tracepoint)
(remote_target::disable_tracepoint): Use phex, not sprintf_vma.
* breakpoint.c (print_recreate_masked_watchpoint): Use phex, not
sprintf_vma.
symfile-mem.c has some assertions about the size of various types, to
ensure that gdb and BFD don't get out of sync in a way that would
cause bugs.
Once CORE_ADDR is always 64-bit, one of these assertions can fail for
a 32-bit BFD build. However, the real requirement here is just that
CORE_ADDR is wider -- because this code promotes a bfd_vma to a
CORE_ADDR.
This patch corrects the assert.
gdb/ChangeLog
2020-03-12 Tom Tromey <tom@tromey.com>
* symfile-mem.c: Update CORE_ADDR size assert.
The selftest.m4 file is used by gdb, gdbserver and gdbsupport, I think
it belongs in gdbsupport.
gdb/ChangeLog:
* selftest.m4: Move to gdbsupport/.
* acinclude.m4: Update path to selftest.m4.
gdbserver/ChangeLog:
* acinclude.m4: Update path to selftest.m4.
gdbsupport/ChangeLog:
* selftest.m4: Moved from gdb/.
* acinclude.m4: Update path to selftest.m4.
While working on the preceding selftests patches, I noticed that some
selftests-specific files are included in the build even when selftests
are disabled, namely disasm-selftest.c and gdbarch-selftests.c. These
files are entirely #if'ed out when building with selftests disabled.
This is not a huge problem, but I think it would make more sense if
these files were simply not built.
With this patch, I propose to put all the selftests-specific source
files into a SELFTESTS_SRCS Makefile variable (even selftest-arch.c,
which is currently added by the configure script).
gdb/ChangeLog:
* Makefile.in (SUBDIR_UNITTESTS_SRCS): Rename to...
(SELFTESTS_SRCS): ... this. Add disasm-selftests.c,
gdbarch-selfselftests.c and selftest-arch.c.
(SUBDIR_UNITTESTS_OBS): Rename to...
(SELFTESTS_OBS): ... this.
(COMMON_SFILES): Remove disasm-selftests.c and
gdbarch-selftests.c.
* configure.ac: Don't add selftest-arch.{c,o} to
CONFIG_{SRCS,OBS}.
* disasm-selftests.c, gdbarch-selftests.c: Remove GDB_SELF_TEST
preprocessor conditions.
The same is done for gdb, gdbserver and gdbsupport. I therefore think
it makes sense to move that to GDB_AC_COMMON.
It is required to move the call to GDB_AC_COMMON so it is before
GDB_AC_SELFTEST in gdbserver/configure.ac, otherwise the $development
variable isn't set when the code behind GDB_AC_SELFTEST executes.
gdb/ChangeLog:
* configure.ac: Don't source bfd/development.sh.
* selftest.m4: Modify comment.
* configure: Re-generate.
gdbserver/ChangeLog:
* configure.ac: Don't source bfd/development.sh, move
GDB_AC_COMMON higher.
* configure: Re-generate.
gdbsupport/ChangeLog:
* configure.ac: Don't source bfd/development.sh.
* common.m4: Source bfd/development.sh.
* configure: Re-generate.
Before commit 3d1e5a43cb ("gdbsupport/configure.ac: source
development.sh"), the GDB build in non-development mode (turn
development to false in bfd/development.sh if you want to try) was
broken because the gdbsupport configure script didn't source
bfd/development.sh to set the development variable.
Since the GDB_AC_SELFTEST macro relies on the `development` variable, I
propose to modify it such that it errors out if $development does not
have an expected value of "true" or "false". This could prevent a
future similar problem from happening while refactoring the configure
scripts. It would have caught the problem fixed by the patch mentioned
earlier.
gdb/ChangeLog:
* selftest.m4 (GDB_AC_SELFTEST): Error out if $development is
not "true" or "false".
* configure: Re-generate.
gdbserver/ChangeLog:
* configure: Re-generate.
gdbsupport/ChangeLog:
* configure: Re-generate.
This is in preparation for deleting deprecated_add_core_fns and
related code.
As a side-effect, this makes it possible to read NetBSD/ARM
core files on non-NetBSD/ARM platforms, subject to PR corefiles/25638.
I have removed this comment:
- /* This is ok: we're running native... */
Since we are using the gdbarch from the regcache, we should be
guaranteed to be calling the right function here, so it shouldn't
matter whether we are running native.
Tested by reading a NetBSD/ARM core file on Linux/x86-64 and NetBSD/ARM;
the "info registers" output matches the one from the system GDB.
gdb/ChangeLog:
2020-03-12 Christian Biesinger <cbiesinger@google.com>
* Makefile.in (HFILES_NO_SRCDIR): Add new arm-nbsd-tdep.h file.
* arm-nbsd-nat.c (arm_supply_gregset): Moved to arm-nbsd-tdep and
renamed to arm_nbsd_supply_gregset.
(fetch_register): Update to call arm_nbsd_supply_gregset.
(fetch_regs): Remove in favor of fetch_register with a -1 regno.
(arm_netbsd_nat_target::fetch_registers): Update.
(fetch_elfcore_registers): Removed.
(_initialize_arm_netbsd_nat): Removed call to deprecated_add_core_fns.
* arm-nbsd-tdep.c (struct arm_nbsd_reg): New struct.
(arm_nbsd_supply_gregset): Moved from arm-nbsd-nat.c and updated to
not require NetBSD system headers.
(arm_nbsd_regset): New struct.
(arm_nbsd_iterate_over_regset_sections): New function.
(arm_netbsd_init_abi_common): Updated to call
set_gdbarch_iterate_over_regset_sections.
* arm-nbsd-tdep.h: New file.
A patch somewhat like this patch has been in Fedora GDB for well over
a decade. The Fedora patch was written by Jan Kratochvil. The Fedora
version prints a warning and attempts to continue. This version will
error out, fatally. An earlier version of this patch was more like
the Fedora version than this one. Simon Marchi recommended use of an
assertion to test for the infinite recursion; I decided to use an
explicit test (with an "if" statement) along with a call to
internal_error() if the condition is met. This way, I could include
a plea to file a bug report.
It was motivated by a customer reported bug (back in 2006!) which
showed infinite mutual recursion between find_pc_sect_line and
find_pc_line. Here is a portion of the backtrace from the bug report:
(gdb) bt
#0 0x00000000004450a4 in lookup_minimal_symbol_by_pc_section (
pc=251700325328, section=0x570f500) at gdb/minsyms.c:484
#1 0x00000000004bbfb2 in find_pc_sect_line (pc=251700325328,
section=0x570f500, notcurrent=0) at gdb/symtab.c:2057
#2 0x00000000004bc480 in find_pc_line (pc=251700325328, notcurrent=0)
at gdb/symtab.c:2232
#3 0x00000000004bc1ff in find_pc_sect_line (pc=251700325328,
section=0x570f500, notcurrent=0) at gdb/symtab.c:2081
... (lots and lots of the same two functions with the same parameters)
#1070 0x00000000004bc480 in find_pc_line (pc=251700325328, notcurrent=0)
at gdb/symtab.c:2232
#1071 0x00000000004bc1ff in find_pc_sect_line (pc=251700325328,
section=0x570f500, notcurrent=0) at gdb/symtab.c:2081
#1072 0x00000000004bc480 in find_pc_line (pc=251700325328, notcurrent=0)
at gdb/symtab.c:2232
#1073 0x00000000004bc1ff in find_pc_sect_line (pc=251700325328,
section=0x570f500, notcurrent=0) at gdb/symtab.c:2081
#1074 0x00000000004bc480 in find_pc_line (pc=251700325328, notcurrent=0)
at gdb/symtab.c:2232
#1075 0x00000000004bc1ff in find_pc_sect_line (pc=251696794399,
section=0x59b0df8, notcurrent=0) at gdb/symtab.c:2081
#1076 0x00000000004bc480 in find_pc_line (pc=251696794399, notcurrent=0)
at gdb/symtab.c:2232
#1077 0x000000000055550e in find_frame_sal (frame=0xb3f3e0, sal=0x7fff1d1a8200)
at gdb/frame.c:1392
#1078 0x00000000004d86fd in set_current_sal_from_frame (frame=0x1648, center=1)
at gdb/stack.c:379
#1079 0x00000000004cf137 in normal_stop () at gdb/infrun.c:3147
...
The test case was a large application. Attempts were made to make a
small(er) test case, but those attempts were not successful.
Therefore, I cannot provide a new test for this patch.
That said, we ought to guard against recursively calling
find_pc_sect_line (via find_pc_line) with the identical PC value that
it had been called with. Should this happen, infinite recursion (as
shown in the above backtrace) is the result. This patch prevents
that from happening.
If this should happens, there is a bug somewhere, perhaps in GDB, perhaps
in some other part of the toolchain or a library. We error out fatally
with a message briefly describing the condition along with a plea to file
a bug report.
I spent some time looking at the surrounding code and commentary which
handle the case of PC being in a stub/trampoline. It first appeared
in the public GDB repository in April, 1999. The ChangeLog entry for
this commit is from 1998-12-31. The relevant portion is:
(find_pc_sect_line): Return correct information if pc is in import
or export stub (trampoline).
What's remarkable about the overall ChangeLog entry is that it's over
2500+ lines long! I believe that this was part of the infamous "HP
merge" (in which insufficient due diligence was given in accepting
a large batch of changes from an outside source). In the years that
followed, much of this code was either significantly revised or
outright removed.
For this particular case, I'm grateful that extensive comments were
provided by "RT". (I haven't been able to figure out who RT is/was.)
I've decided against attempting to revise this stub/trampoline handling
code any further than adding Jan's test which prevents an obvious case
of infinite recursion.
I've tested on Fedora 31, x86-64. I see no regressions. I've also
searched the logfile for the new message, but as expected, no message
was found (which is good).
gdb/ChangeLog:
* symtab.c (find_pc_sect_line): Add check which prevents infinite
recursion.
Change-Id: I595470be6ab5f61ca7e4e9e70c61a252c0deaeaa
While compiling with clang, I noticed it didn't catch cases where my
function declaration didn't match my function definition. This is
normally caught by gcc with -Wmissing-declarations.
On clang, this is caught by -Wmissing-prototypes instead.
Note that on gcc, -Wmissing-prototypes also exists, but is only valid
for C and Objective-C. It gets correctly rejected by the configure
script since gcc rejects it with:
cc1plus: error: command line option '-Wmissing-prototypes' is valid for C/ObjC but not for C++ -Werror
So this warning flag ends up not used for gcc (which is what we want).
gdb/ChangeLog:
* configure: Re-generate.
gdbserver/ChangeLog:
* configure: Re-generate.
gdbsupport/ChangeLog:
* configure: Re-generate.
* warning.m4: Enable -Wmissing-prototypes.
A comment in ada-typeprint.c mentions the Unchecked_Variant pragma.
However, this does not exist, and the comment should actually mention
Unchecked_Union.
gdb/ChangeLog
2020-03-11 Tom Tromey <tromey@adacore.com>
* ada-typeprint.c (print_choices): Fix comment.
This commit:
commit 8c95582da8
Date: Mon Dec 30 21:04:51 2019 +0000
gdb: Add support for tracking the DWARF line table is-stmt field
Introduced an invalid memory access, by reading outside the bounds of
an array.
This would cause this valgrind error:
==7633== Invalid read of size 4
==7633== at 0x4D002C: buildsym_compunit::record_line(subfile*, int, unsigned long, bool) (buildsym.c:688)
==7633== by 0x5F60A5: dwarf_record_line_1(gdbarch*, subfile*, unsigned int, unsigned long, bool, dwarf2_cu*) (read.c:19956)
==7633== by 0x5F63B0: lnp_state_machine::record_line(bool) (read.c:20024)
==7633== by 0x5F5DD5: lnp_state_machine::handle_special_opcode(unsigned char) (read.c:19851)
==7633== by 0x5F6706: dwarf_decode_lines_1(line_header*, dwarf2_cu*, int, unsigned long) (read.c:20135)
==7633== by 0x5F6C57: dwarf_decode_lines(line_header*, char const*, dwarf2_cu*, dwarf2_psymtab*, unsigned long, int) (read.c:20328)
==7633== by 0x5DF5F1: handle_DW_AT_stmt_list(die_info*, dwarf2_cu*, char const*, unsigned long) (read.c:10748)
==7633== by 0x5DF823: read_file_scope(die_info*, dwarf2_cu*) (read.c:10796)
==7633== by 0x5DDA63: process_die(die_info*, dwarf2_cu*) (read.c:9815)
==7633== by 0x5DD44A: process_full_comp_unit(dwarf2_per_cu_data*, language) (read.c:9580)
==7633== by 0x5DAB58: process_queue(dwarf2_per_objfile*) (read.c:8867)
==7633== by 0x5CB30E: dw2_do_instantiate_symtab(dwarf2_per_cu_data*, bool) (read.c:2374)
==7633== Address 0xa467f48 is 8 bytes before a block of size 16,024 alloc'd
==7633== at 0x4C2CDCB: malloc (vg_replace_malloc.c:299)
==7633== by 0x451FC4: xmalloc (alloc.c:60)
==7633== by 0x4CFFDF: buildsym_compunit::record_line(subfile*, int, unsigned long, bool) (buildsym.c:678)
==7633== by 0x5F60A5: dwarf_record_line_1(gdbarch*, subfile*, unsigned int, unsigned long, bool, dwarf2_cu*) (read.c:19956)
==7633== by 0x5F63B0: lnp_state_machine::record_line(bool) (read.c:20024)
==7633== by 0x5F5DD5: lnp_state_machine::handle_special_opcode(unsigned char) (read.c:19851)
==7633== by 0x5F6706: dwarf_decode_lines_1(line_header*, dwarf2_cu*, int, unsigned long) (read.c:20135)
==7633== by 0x5F6C57: dwarf_decode_lines(line_header*, char const*, dwarf2_cu*, dwarf2_psymtab*, unsigned long, int) (read.c:20328)
==7633== by 0x5DF5F1: handle_DW_AT_stmt_list(die_info*, dwarf2_cu*, char const*, unsigned long) (read.c:10748)
==7633== by 0x5DF823: read_file_scope(die_info*, dwarf2_cu*) (read.c:10796)
==7633== by 0x5DDA63: process_die(die_info*, dwarf2_cu*) (read.c:9815)
==7633== by 0x5DD44A: process_full_comp_unit(dwarf2_per_cu_data*, language) (read.c:9580)
gdb/ChangeLog:
* buildsyms.c (buildsym_compunit::record_line): Avoid accessing
previous item in the list, when the list has no items.
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.
Gcc supports an option -feliminate-dwarf2-dups (up until gcc-7, removed in
gcc-8).
When running tests with target board unix/-feliminate-dwarf2-dups, we run
into:
...
(gdb) PASS: gdb.ada/arraydim.exp: print m'length(3)
ptype global_3dim_for_gdb_testing^M
type = array (Unexpected type in ada_discrete_type_low_bound.^M
(gdb) FAIL: gdb.ada/arraydim.exp: ptype global_3dim_for_gdb_testing
...
The DWARF for the variable global_3dim_for_gdb_testing looks as follows:
...
<0><824>: Abbrev Number: 1 (DW_TAG_compile_unit)
<825> DW_AT_name : src/gdb/testsuite/gdb.ada/arraydim/inc.c
<1><832>: Abbrev Number: 2 (DW_TAG_array_type)
<833> DW_AT_type : <0x874>
<2><837>: Abbrev Number: 3 (DW_TAG_subrange_type)
<838> DW_AT_type : <0x84a>
<83c> DW_AT_upper_bound : 0
<2><83d>: Abbrev Number: 3 (DW_TAG_subrange_type)
<83e> DW_AT_type : <0x84a>
<842> DW_AT_upper_bound : 1
<2><843>: Abbrev Number: 3 (DW_TAG_subrange_type)
<844> DW_AT_type : <0x84a>
<848> DW_AT_upper_bound : 2
<2><849>: Abbrev Number: 0
<1><84a>: Abbrev Number: 4 (DW_TAG_typedef)
<84b> DW_AT_type : <0x86d>
<1><84f>: Abbrev Number: 0
<0><85b>: Abbrev Number: 5 (DW_TAG_compile_unit)
<861> DW_AT_name : src/gdb/testsuite/gdb.ada/arraydim/inc.c
<1><86d>: Abbrev Number: 6 (DW_TAG_base_type)
<86e> DW_AT_byte_size : 8
<86f> DW_AT_encoding : 7 (unsigned)
<870> DW_AT_name : long unsigned int
<1><874>: Abbrev Number: 7 (DW_TAG_base_type)
<875> DW_AT_byte_size : 4
<876> DW_AT_encoding : 5 (signed)
<877> DW_AT_name : int
<1><87b>: Abbrev Number: 8 (DW_TAG_variable)
<87c> DW_AT_name : global_3dim_for_gdb_testing
<882> DW_AT_type : <0x832>
<886> DW_AT_external : 1
...
The DWARF contains an anonymous typedef at 0x84a, referring to 0x86d.
Strictly speaking, the anonymous typedef is illegal DWARF, because a
DW_TAG_typedef is defined to have an DW_AT_name attribute containing the name
of the typedef as it appears in the source program.
The DWARF reading code creates a corresponding type for this typedef, which
goes on to confuse the code handling arrays.
Rather than trying to support the type representing this anonymous typedef in
all the locations where it causes problems, fix this by treating the anonymous
typedef as a forwarder DIE in the DWARF reader.
Tested on x86_64-linux, with target boards unix and
unix/-feliminate-dwarf2-dups.
This fixes ~85 failures for unix/-feliminate-dwarf2-dups.
gdb/ChangeLog:
2020-03-07 Tom de Vries <tdevries@suse.de>
* dwarf2/read.c (read_typedef): Treat anonymous typedef as forwarder
DIE.
While working on complex number support, I found a couple of
apparently obsolete coments. This removes them.
2020-03-07 Tom Tromey <tom@tromey.com>
* valops.c (value_literal_complex): Remove obsolete comment.
* gdbtypes.h (enum type_code) <TYPE_CODE_FLT>: Remove obsolete
comment.
[ Migrating this from Gerrit: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/321 ]
I noticed that some functions in infcmd and infrun call each other and
all call inferior_thread, while they could just get the thread_info
pointer from their caller. That means less calls to inferior_thread, so
less reliance on global state, since inferior_thread reads
inferior_ptid.
The paths I am unsure about are:
- fetch_inferior_event calls...
- step_command_fsm::should_stop calls...
- prepare_one_step
and
- process_event_stop_test calls...
- set_step_info
Before this patch, prepare_one_step gets the thread pointer using
inferior_thread. After this patch, it gets it from the
execution_control_state structure in fetch_inferior_event. Are we sure
that the thread from the execution_control_state structure is the same
as the one inferior_thread would return? This code path is used when a
thread completes a step, but the user had specified a step count (e.g.
"step 5") so we decide to do one more step. It would be strange (and
even a bug I suppose) if the thread in the ecs structure in
fetch_inferior_event was not the same thread that is prepared to stepped
by prepare_one_step. So I believe passing the ecs thread is fine.
The same logic applies to process_event_stop_test calling
set_step_info.
gdb/ChangeLog:
* infrun.h: Forward-declare thread_info.
(set_step_info): Add thread_info parameter, add doc.
* infrun.c (set_step_info): Add thread_info parameter, move doc
to header.
* infrun.c (process_event_stop_test): Pass thread to
set_step_info call.
* infcmd.c (set_step_frame): Add thread_info pointer, pass it to
set_step_info.
(prepare_one_step): Add thread_info parameter, pass it to
set_step_frame and prepare_one_step (recursive) call.
(step_1): Pass thread to prepare_one_step call.
(step_command_fsm::should_stop): Pass thread to
prepare_one_step.
(until_next_fsm): Pass thread to set_step_frame call.
(finish_command): Pass thread to set_step_info call.
The target_get_tib_address call always fails in this case, and there is an
error when changing the program with the file command:
(gdb) file allocer64.exe
Reading symbols from allocer64.exe...
You can't do that when your target is `exec'
Now it will skip this part, there is no need to rebase the executable without
an inferior anyways.
gdb/ChangeLog:
2020-03-06 Hannes Domani <ssbssa@yahoo.de>
* windows-tdep.c (windows_solib_create_inferior_hook):
Check if inferior is running.
Replace "the the" by "the".
gdb/ChangeLog:
2020-03-06 Tom de Vries <tdevries@suse.de>
* NEWS: Fix "the the".
* ctfread.c: Same.
gdb/doc/ChangeLog:
2020-03-06 Tom de Vries <tdevries@suse.de>
* gdb.texinfo: Fix "the the".
gdb/testsuite/ChangeLog:
2020-03-06 Tom de Vries <tdevries@suse.de>
* README: Fix "the the".
* gdb.base/dprintf.exp: Same.
Using verbose, we get some detail on symbol loading:
...
$ gdb a.out -iex "set verbose on"
Reading symbols from a.out...
Reading in symbols for /home/vries/hello.c...done.
(gdb)
...
And using debug symtab-create, much more detail:
...
$ gdb a.out -iex "set verbose on" -iex "set debug symtab-create 1"
Reading symbols from a.out...
Reading minimal symbols of objfile /data/gdb_versions/devel/lto/a.out ...
Installing 30 minimal symbols of objfile /data/gdb_versions/devel/lto/a.out.
Done reading minimal symbols.
Creating one or more psymtabs for objfile /data/gdb_versions/devel/lto/a.out ...
Created psymtab 0x35a3de0 for module ../sysdeps/x86_64/start.S.
Created psymtab 0x353e4e0 for module init.c.
Created psymtab 0x353e560 for module ../sysdeps/x86_64/crti.S.
Created psymtab 0x353e5e0 for module /home/vries/hello.c.
Created psymtab 0x35bd530 for module elf-init.c.
Created psymtab 0x35bd5b0 for module ../sysdeps/x86_64/crtn.S.
Reading in symbols for /home/vries/hello.c...Created compunit symtab 0x354bd20 for hello.c.
done.
(gdb)
...
The "Created compunit symtab" message gets inbetween the "Reading in symbols"
and the trailing "done.". [ Strictly speaking this is a regression since
commit faa17681cc "Make gdb_flush also flush the wrap buffer", but the
same problem happens when using -batch before this commit. ]
Fix this by removing the trailing "done." altogether, such that we get:
...
Created psymtab 0x3590520 for module ../sysdeps/x86_64/crtn.S.
Reading in symbols for /home/vries/hello.c...
Created compunit symtab 0x359dd20 for hello.c.
(gdb)
...
[ Alternatively, we could fix this emitting a "Done reading in symbols" line
or some such, like is done for minimal symbols. See above. ]
[ Note: Removing the trailing "done." for the "Reading symbols from" message
was done in commit 3453e7e409 'Clean up "Reading symbols" output'. ]
Build and reg-tested on x86_64-linux.
gdb/ChangeLog:
2020-03-06 Tom de Vries <tdevries@suse.de>
* psymtab.c (psymtab_to_symtab): Don't print "done.".
Copy the .dir-locls.el file from gdb/ to gdbserver/ and gdbsupport/ so
that we get the GNU/GDB style when editing these files in Emacs.
I initially wanted to remove the (c-mode . ((mode . c++))) that
switches c-mode files into c++-mode as we store C++ code in *.cc files
in the gdbserver/ directory, unlike gdb/ where we use *.c, however, I
was forgetting about the header files - we still use *.h for our C++
header files, so for now I left the settings in place to open all C
files in c++-mode.
We now have three copies of this file, which are all identical. It
would be nice if we could remove this duplication, however, for now we
haven't found a good way to do this.
Some options considered were:
1. Use symlinks to only have one copy of the file. This was
rejected as not all targets support symlinks in the way.
2. Have two of the .dir-locals.el files contain some mechanism by
which the third copy of the file is sourced. Though this would, in
theory, be possible, it would involve some advanced Emacs scripting,
would be fragile, and a maintenance burdon.
3. Move the .dir-locals up into top level src/ directory, then use
Emacs dir-locals directory pattern matching to only apply the rules
for the three directories we care about. The problem is that each
directory has to be listed separately, so we still end up having to
duplicate all the rules.
In the end, it was decided that having three copies of the file,
though not ideal, is probably easiest for now. This was all discussed
in this mailing list thread:
https://sourceware.org/ml/gdb-patches/2020-03/msg00024.html
The copyright date in the new files is left as for gdb/.dir-locals.el,
as the new files are a copy of the old, this is inline with this rule:
https://sourceware.org/gdb/wiki/ContributionChecklist#Copyright_Header
gdb/ChangeLog:
* .dir-locals.el: Add a comment referencing the other copies of
this file.
gdbserver/ChangeLog:
* .dir-locals.el: New file.
gdbsupport/ChangeLog:
* .dir-locals.el: New file.
Create .gitattributes files in gdb/, gdbserver/, and gdbsupport/.
The files specify cpp-style diffs for .h and .c files. This is
particularly helpful if a class in a header file is modified.
For instance, if the `stop_requested` field of `thread_info` in
gdb/gdbthread.h is modified, we get the following diff with
'git diff' (using git version 2.17.1):
@@ -379,7 +379,7 @@ public:
struct target_waitstatus pending_follow;
/* True if this thread has been explicitly requested to stop. */
- int stop_requested = 0;
+ bool stop_requested = 0;
/* The initiating frame of a nexting operation, used for deciding
which exceptions to intercept. If it is null_frame_id no
Note that the context of the change shows up as 'public:'; not so
useful. With the .gitattributes file, we get:
@@ -379,7 +379,7 @@ class thread_info : public refcounted_object
struct target_waitstatus pending_follow;
/* True if this thread has been explicitly requested to stop. */
- int stop_requested = 0;
+ bool stop_requested = 0;
/* The initiating frame of a nexting operation, used for deciding
which exceptions to intercept. If it is null_frame_id no
The context is successfully shown as 'class thread_info'.
This patch creates a .gitattributes file per each of gdb, gdbserver,
and gdbsupport folders. An alternative would be to define the
attributes in the root folder -- this would impact all the top-level
folders, though. I opted for the more conservative approach.
gdb/ChangeLog:
2020-03-05 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* .gitattributes: New file.
gdbserver/ChangeLog:
2020-03-05 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* .gitattributes: New file.
gdbsupport/ChangeLog:
2020-03-05 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* .gitattributes: New file.
This introduces a string cache on the per-BFD object, replacing the
macro and filename caches. Both of these caches just store strings,
so this consolidation by itself saves a little memory (about the size
of a bcache per objfile).
Then this patch switches some allocations on the objfile obstack to
use this bcache instead. This saves more space; and turns out to be a
bit faster as well.
Here are the before and after "maint time" + "maint space" results of
"file ./gdb":
Command execution time: 4.664021 (cpu), 4.728518 (wall)
Space used: 39190528 (+29212672 for this command)
Command execution time: 4.216209 (cpu), 4.107023 (wall)
Space used: 36667392 (+26689536 for this command)
The main interface to the string cache is a new pair of overloaded
methods, objfile::intern.
gdb/ChangeLog
2020-03-04 Tom Tromey <tom@tromey.com>
* symmisc.c (print_symbol_bcache_statistics)
(print_objfile_statistics): Update.
* symfile.c (allocate_symtab): Use intern.
* psymtab.c (partial_symtab::partial_symtab): Use intern.
* objfiles.h (struct objfile_per_bfd_storage) <filename_cache,
macro_cache>: Remove.
<string_cache>: New member.
(struct objfile) <intern>: New methods.
* elfread.c (elf_symtab_read): Use intern.
* dwarf2/read.c (fixup_go_packaging): Intern package name.
(dwarf2_compute_name, dwarf2_physname)
(create_dwo_unit_in_dwp_v1, create_dwo_unit_in_dwp_v2): Intern
names.
(guess_partial_die_structure_name): Update.
(partial_die_info::fixup): Intern name.
(dwarf2_canonicalize_name): Change parameter to objfile. Intern
name.
(dwarf2_name): Intern name. Update.
* buildsym.c (buildsym_compunit::get_macro_table): Use
string_cache.
I noticed that gnutarget was not "const". Since writing through this
pointer would probably be a bug, I think it ought to be. This patch
makes the change.
gdb/ChangeLog
2020-03-04 Tom Tromey <tom@tromey.com>
* jit.c (bfd_open_from_target_memory): Make "target" const.
* corefile.c (gnutarget): Now const.
* gdbcore.h (gnutarget): Now const.
Revert the change since it breaks existing behavior of "info registers"
for some architectures. At least AArch64 and ARM are impacted by this change.
gdb/ChangeLog:
2020-03-04 Luis Machado <luis.machado@linaro.org>
Revert aa66aac47b due to regressions
in "info registers" for AArch64/ARM.
The change caused "info registers" to not print GPR's.
gdb/ChangeLog:
2020-02-01 Shahab Vahedi <shahab@synopsys.com>
* target-descriptions.c (tdesc_register_in_reggroup_p): Return 0
when reg->group is empty and reggroup is not.
A customer reported a failure to unwind in a certain core dump. A
lengthy investigation showed that the problem came from the
interaction between the tailcall and inline frame sniffers.
Normally, the regular DWARF unwinder may discover a chain of tail
calls ending in the current frame. In this case, it sets a member on
the dwarf2_frame_cache object, so that a subsequent call into the
tailcall sniffer will create the tailcall frames.
However, in this scenario, what happened is that the DWARF unwinder
did find tailcall frames -- but then the PC of the first such frame
was recognized and claimed by the inline frame sniffer.
This then caused unwinding to go astray further up the stack.
This patch fixes the problem by arranging for the tailcall sniffer to
be called before the inline sniffer. This way, if a DWARF frame has
tailcall information, the tailcalls will always be processed first.
This is safe to do, because the tailcall sniffer can only claim a
frame if the previous frame did in fact find this information. (So,
for example, if no DWARF frame is ever found, then this sniffer will
never trigger.)
This patch also partially reverts:
commit 1ec56e88aa
Author: Pedro Alves <palves@redhat.com>
Date: Fri Nov 22 13:17:46 2013 +0000
Eliminate dwarf2_frame_cache recursion, don't unwind from the dwarf2 sniffer (move dwarf2_tailcall_sniffer_first elsewhere).
That patch moved the call to dwarf2_tailcall_sniffer_first out of
dwarf2_frame_cache, and into dwarf2_frame_prev_register. However, in
this situation, this is too late -- by the time
dwarf2_frame_prev_register is called, the frame in question is already
recognized by the inline frame sniffer.
Rather than fully revert that patch, though, this just arranges to
call dwarf2_tailcall_sniffer_first from dwarf2_frame_cache -- which is
called shortly after the DWARF frame sniffer succeeds, via
compute_frame_id.
I don't know how to write a test case for this.
gdb/ChangeLog
2020-03-03 Tom Tromey <tromey@adacore.com>
* dwarf2/frame.c (struct dwarf2_frame_cache)
<checked_tailcall_bottom, entry_cfa_sp_offset,
entry_cfa_sp_offset_p>: Remove members.
(dwarf2_frame_cache): Call dwarf2_tailcall_sniffer_first.
(dwarf2_frame_prev_register): Don't call
dwarf2_tailcall_sniffer_first.
(dwarf2_append_unwinders): Don't append tailcall unwinder.
* frame-unwind.c (add_unwinder): New fuction.
(frame_unwind_init): Use it. Add tailcall unwinder.
GDB is not able to print logical true values for Flang compiler.
Actual result:
(gdb) p l
$1 = 4294967295
Expected result:
(gdb) p l
$1 = .TRUE.
This is due to GDB expecting representation of true value being 1.
The Fortran standard doesnt specify how LOGICAL types are represented.
Different compilers use different non-zero values to represent logical
true. The gfortran compiler uses 1 to represent logical true and the
flang compiler uses -1. GDB should accept all the non-zero values as
true.
This is achieved by handling TYPE_CODE_BOOL in f_val_print and
printing any non-zero value as true.
gdb/ChangeLog:
* f-valprint.c (f_val_print): Handle TYPE_CODE_BOOL, any non-zero
value should be printed as true.
gdb/testsuite/ChangeLog:
* gdb.fortran/logical.exp: Add tests that any non-zero value is
printed as true.
Windows executables linked with -dynamicbase get a new base address
when loaded, which makes debugging impossible if the executable isn't
also rebased in gdb.
The new base address is read from the Process Environment Block.
gdb/ChangeLog:
2020-03-03 Hannes Domani <ssbssa@yahoo.de>
* windows-tdep.c (windows_solib_create_inferior_hook): New function.
(windows_init_abi): Set and use windows_so_ops.
Back at:
commit 1f6f6e21fa
Author: Philippe Waroquiers <philippe.waroquiers@skynet.be>
Date: Mon Jun 10 21:41:51 2019 +0200
Ensure GDB printf command can print convenience var strings without a target.
GDB was extended in order to allow the printing of convenience
variables that are strings without a target. However, this introduced
a regression that hasn't been caught by our testsuite (because there
were no tests for it).
The problem happens when we try to print a convenience variable that
holds the address of a string in the inferior. The following
two-liners can reproduce the issue:
$ echo -e 'int main(){const char a[]="test";return 0;}' | gcc -x c - -O0-g3
$ ./gdb/gdb --data-directory ./gdb/data-directory -q ./a.out -ex 'start' -ex 'set $x = (const char *) (&a[0] + 2)' -ex 'printf "%s\n", $x'
After some investigation, I found that the problem happens on
printcmd.c:printf_c_string. In the case above, we're taking the first
branch of the 'if' condition, which assumes that there will be a value
to be printed at "value_contents (value)". There isn't. We actually
need to obtain the address that the variable points to, and read the
contents from memory.
It seems to me that we should avoid this branch if the TYPE_CODE of
"value_type (value)" is TYPE_CODE_PTR (i.e., a pointer to the
inferior's memory). This is what this patch does.
I took the liberty to extend the current testcase under
gdb.base/printcmds.exp and create a test that exercises this scenario.
No regressions have been found on Buildbot.
gdb/ChangeLog:
2020-03-03 Sergio Durigan Junior <sergiodj@redhat.com>
* printcmd.c (print_c_string): Check also for TYPE_CODE_PTR
when verifying if dealing with a convenience variable.
gdb/testsuite/ChangeLog:
2020-03-03 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.base/printcmds.exp: Add test to verify printf of a
variable holding an address.
I noticed GDB didn't know a particular AT tag (51) when doing some debugging.
Turns out we're missing a few entries compared to glibc's headers.
This patch adds them to GDB and fixes a failure in gdb.base/auxv.exp as
a result.
gdb/ChangeLog:
2020-03-03 Luis Machado <luis.machado@linaro.org>
* auxv.c (default_print_auxv_entry): Add new AUXV entries.
This function returns the result of a quite big condition. I think it
would be more readeable if it was broken up in smaller pieces and
commented. This is what this patch does.
I also introduced gdbarch_supports_displaced_stepping, since it shows
the intent better than checking for gdbarch_displaced_step_copy_insn_p.
I also used that new function in displaced_step_prepare_throw.
I also updated the comment on top of can_use_displaced_stepping, which
seemed a bit outdated with respect to non-stop. The comment likely
dates from before it was possible to have targets that always operate
non-stop under the hood, even when the user-visible mode is all-stop.
No functional changes intended.
gdb/ChangeLog:
* infrun.c (gdbarch_supports_displaced_stepping): New.
(use_displaced_stepping): Break up conditions in smaller pieces.
Use gdbarch_supports_displaced_stepping.
(displaced_step_prepare_throw): Use
gdbarch_supports_displaced_stepping.
This commit aims to give a cleaner mechanism by which the user can
prevent GDB from trying to load any previous command history.
Currently the user can change the path to the history file, either
using a command line flag, or by setting the GDBHISTFILE environment
variable, and if the path is set to a non-existent file, then
obviously GDB wont load any command history. However, this feels like
a bit of a bodge, I'd like to add an official mechanism by which we
can disable command history loading.
Why would we want to prevent command history loading? The specific
use case I have is GDB starting with a CWD that is a network mounted
directory, and there is no command history present. Still GDB will
access the network in order to check for the file. In my particular
use case I'm actually starting a large number of GDB instances in
parallel, all in the same network mounted directory, the large number
of network accesses looking for this file introduces a noticeable
delay at GDB startup.
The approach I'm proposing here is a slight adjustment to the current
rules for setting up the history filename. Currently, if a user does
this, they see an error:
(gdb) set history filename
Argument required (filename to set it to.).
However, if a user does this:
$ GDBHISTFILE= gdb --quiet
(gdb) set history save on
(gdb) q
warning: Could not rename -gdb18416~ to : No such file or directory
So, we already have a bug in this area. My plan is to allow the empty
filename to be accepted, and for this to mean, neither load, nor save
the command history.
This does mean that we now have two mechanisms to prevent saving the
command history:
(gdb) set history filename
or
(gdb) set history save off
But the only way to prevent loading the command history is to set the
filename to the empty string _before_ you get to a GDB prompt, either
using a command line option, or the environment variable.
I've updated some of the show commands, for example this session:
(gdb) set history filename
(gdb) show history filename
There is no filename currently set for recording the command history in.
(gdb) show history save
Saving of the history record on exit is off.
(gdb) set history save on
(gdb) show history save
Saving of the history is disabled due to the value of 'history filename'.
(gdb) set history filename /tmp/hist
(gdb) show history save
Saving of the history record on exit is on.
I've updated the manual, and added some tests.
gdb/ChangeLog:
* NEWS: Mention new behaviour of the history filename.
* top.c (write_history_p): Add comment.
(show_write_history_p): Add header comment, give a different
message when history writing is on, but the history filename is
empty.
(history_filename): Add comment.
(history_filename_empty): New function.
(show_history_filename): Add header comment, give a different
message when the filename is empty.
(init_history): Compare history_filename against nullptr, and only
read history if the filename is not empty.
(set_history_filename): Add header comment, and only make
non-empty filenames absolute.
(init_main): Make the filename argument to 'set history filename'
optional.
gdb/doc/ChangeLog:
* gdb.texinfo (Command History): Extend description for
GDBHISTFILE and GDBHISTSIZE, add detail about the filename for
'set history filename' being optional. Describe the effect of an
empty history filename on 'set history save on'.
gdb/testsuite/ChangeLog:
* gdb.base/default.exp: Remove test of 'set history filename'.
* gdb.base/gdbinit-history.exp: Add tests for setting the history
filename to the empty string.
* lib/gdb.exp (gdb_init): Unset environment variables GDBHISTFILE
and GDBHISTSIZE.
Change-Id: Ia586e4311182fac99113b60f11ef8a11fbd5450b
The floating point register interface has changed to this:
https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h
It now uses VFP instead of FPA registers. This patch updates
arm-nbsd-nat.c accordingly.
Also implements read_description so that these registers are correctly
printed by "info registers" et al.
Tested by compiling & running on arm-netbsd on qemu.
gdb/ChangeLog:
2020-03-02 Christian Biesinger <cbiesinger@google.com>
* arm-nbsd-nat.c (arm_supply_fparegset): Rename to...
(arm_supply_vfpregset): ...this, and update to use VFP registers.
(fetch_fp_register): Update.
(fetch_fp_regs): Update.
(store_fp_register): Update.
(store_fp_regs): Update.
(arm_netbsd_nat_target::read_description): New function.
(fetch_elfcore_registers): Update.
With this commit:
commit 5b6d1e4fa4
Date: Fri Jan 10 20:06:08 2020 +0000
Multi-target support
There was a regression in GDB's support for older aspects of the
remote protocol. Specifically, when a target sends the 'S' stop reply
packet (which doesn't include a thread-id) then GDB has to figure out
which thread actually stopped.
Before the above commit GDB figured this out by using inferior_ptid in
process_stop_reply, which contained the ptid of the current
process/thread. This would be fine for single threaded
targets (which is the only place using an S packet makes sense), but
in the general case, relying on inferior_ptid for processing a stop is
wrong - there's no reason to believe that what was GDB's current
thread will be the same thread that just stopped in the target.
With the above commit the inferior_ptid now has the value null_ptid
inside process_stop_reply, this can be seen in do_target_wait, where
we call switch_to_inferior_no_thread before calling do_target_wait_1.
The problem this causes can be seen in the new test that runs
gdbserver using the flag --disable-packet=T, and causes GDB to throw
this assertion:
inferior.c:279: internal-error: inferior* find_inferior_pid(process_stratum_target*, int): Assertion `pid != 0' failed.
A similar problem was fixed in this commit:
commit 3cada74087
Date: Thu Jan 11 00:23:04 2018 +0000
Fix backwards compatibility with old GDBservers (PR remote/22597)
However, this commit deals with the case where the T packet doesn't
include a thread-id, not the S packet case. This commit solves the
problem providing a thread-id at the GDB side if the remote target
doesn't provide one. The thread-id provided comes from
remote_state::general_thread, however, though this does work, I don't
think it is the ideal solution.
The remote_state tracks two threads, the continue_thread and the
general_thread, these are updated when GDB asks the remote target to
switch threads. The general_thread is set before performing things
like register or memory accesses, and the continue_thread is set
before things like continue or step commands. Further, the
general_thread is updated after a target stops to reference the thread
that stopped.
The first thing to note from the above description is that we have a
cycle of dependency, when a T packet arrives without a thread-id we
fill in the thread-id from the general_thread data. The thread-id
from the stop event is then used to set the general_thread. This in
itself feels a little weird.
The second question is why use the general_thread at all? You'd think
given how they are originally set that the continue thread would be a
better choice. The problem with this is that the continue_thread, if
the user just does "continue", will be set to the minus_one_ptid, in
the remote protocol this means all threads. When the stop arrives
with no thread-id and we use continue_thread we end up with a very
similar assertion to before because we now end up trying to lookup a
thread using the minus_one_ptid. By contrast, once GDB has connected
to a remote target the general_thread will be set to a valid
thread-id, after which, if the target is single threaded, and stop
events arrive without a thread-id, everything works fine.
There is one slight weirdness with the above behaviour though. When
GDB first connects to the remote target inferior_ptid is null_ptid,
however, upon connecting we query the remote for its threads. As the
thread information arrives GDB adds the threads to its internal
database, and this process involves setting inferior_ptid to the id of
each new thread in turn. Once we know about all the threads we wait
for a stop event from the remote target to indicate that GDB is now in
control of the target.
The problem is that after adding the new threads we don't reset
inferior_ptid, and the code path we use to wait for a stop event from
the target also doesn't reset inferior_ptid, so it turns out that
during the initial connection inferior_ptid is not null_ptid. This is
lucky, because during the initial connection the general_thread
variable _is_ set to null_ptid.
So, during the initial connection, if the first stop event is missing
a thread-id then we "provide" a thead-id from general_thread. This
turns out to be null_ptid meaning no thread-id is known, and then
during process_stop_reply we fill in the missing thread-id using
inferior_ptid.
This was all discussed on the mailing list here:
https://sourceware.org/ml/gdb-patches/2020-02/msg01011.html
My proposal for a fix then is:
1. Move the call to switch_to_inferior_no_thread into
do_target_wait_1, this means that in all cases where we are waiting
for an inferior the inferior_ptid will be set to null_ptid. This is
good as no wait code should rely on inferior_ptid.
2. Remove the use of general_thread from the 'T' packet processing.
The general_thread read here was only ever correct by chance, and we
shouldn't be using it this way.
3. Remove use of inferior_ptid from process_stop_event as this is
wrong, and will always be null_ptid now anyway.
4. When a stop_event has null_ptid due to a lack of thread-id (either
from a T packet or an S packet) then pick the first non exited thread
in the target and use that. This will be fine for single threaded
targets. A multi-thread or multi-inferior aware remote target
should be using T packets with a thread-id, so we give a warning if
the target is multi-threaded, and we are still missing a thread-id.
5. Extend the existing test that covered the T packet with missing
thread-id to also cover the S packet.
gdb/ChangeLog:
* remote.c (remote_target::remote_parse_stop_reply): Don't use the
general_thread if the stop reply is missing a thread-id.
(remote_target::process_stop_reply): Use the first non-exited
thread if the target didn't pass a thread-id.
* infrun.c (do_target_wait): Move call to
switch_to_inferior_no_thread to ....
(do_target_wait_1): ... here.
gdb/testsuite/ChangeLog:
* gdb.server/stop-reply-no-thread.exp: Add test where T packet is
disabled.
* defs.h includes config.h
* config.h may define _GNU_SOURCE
* if _GNU_SOURCE is defined, that must be before including any system
header (see feature_test_macro(7))
This is necessary to ensure that a prototype for mkostemp() is brought
into scope by <stdlib.h> when compiling filestuff.h, on platforms where
_GNU_SOURCE isn't unconditionally defined for C++.
In file included from ../../gdb/../gdbsupport/scoped_fd.h:24,
from ../../gdb/debuginfod-support.c:22:
../../gdb/../gdbsupport/filestuff.h: In function ‘int gdb_mkostemp_cloexec(char*, int)’:
../../gdb/../gdbsupport/filestuff.h:59:10: error: ‘mkostemp’ was not declared in this scope; did you mean ‘mkstemp’?
gdb/ChangeLog:
2020-02-29 Jon Turney <jon.turney@dronecode.org.uk>
* debuginfod-support.c: Include defs.h first.
When language is set to auto, part of loading an executable is to update the
language accordingly. This is implemented by set_initial_language.
In case of a c++ executable without DW_AT_main_subprogram,
set_initial_language finds "main" in the minimal symbols, and does a lookup of
"main" in the symbol tables to determine the language of the symbol, and uses
that as initial language.
The symbol lookup is done using lookup_symbol which is a wrapper around
lookup_symbol_in_language, using the current language.
So, consider two c++ executables a.out and b.out, which we'll load one after
another. If we track the resulting lookup_symbol_in_language calls:
...
$ gdb -batch \
-ex "b lookup_symbol_in_language" \
-ex r -ex c -ex c \
--args gdb
...
we find that indeed lookup_symbol_in_language is called once using language_c, and
once using language_c_plus:
...
(gdb) file a.out
Reading symbols from a.out...
Breakpoint 1, lookup_symbol_in_language (name=0x5555568c2050 "main", \
block=0x0, domain=VAR_DOMAIN, lang=language_c, is_a_field_of_this=0x0) \
at ../../gdb/symtab.c:1905
1905 {
(gdb) file b.out
Load new symbol table from "b.out"? (y or n) y
Reading symbols from b.out...
Breakpoint 1, lookup_symbol_in_language (name=0x5555568c2030 "main", \
block=0x0, domain=VAR_DOMAIN, lang=language_cplus, is_a_field_of_this=0x0) \
at ../../gdb/symtab.c:1905
1905 {
(gdb)
...
It seems like a bad idea to have the previous language play a role
in determining the executable language.
Fix this by using lookup_symbol_in_language in set_initial_language with the
default language c as argument.
Tested on x86_64-linux.
gdb/ChangeLog:
2020-02-28 Tom de Vries <tdevries@suse.de>
* symfile.c (set_initial_language): Use default language for lookup.
Running anything with the fission.exp board fails since commit
c0ab21c22b ("Replace init_cutu_and_read_dies with a class").
GDB crashes while reading the DWARF info. cu is NULL in
read_signatured_type:
Thread 1 "gdb" received signal SIGSEGV, Segmentation fault.
0x000055555780663e in read_signatured_type
sig_type=0x6210000c3600) at /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:22782
22782 gdb_assert (cu->die_hash == NULL);
(top-gdb) bt
#0 0x000055555780663e in read_signatured_type (sig_type=0x6210000c3600) at /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:22782
#1 0x00005555578062dd in load_full_type_unit (per_cu=0x6210000c3600) at /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:22758
#2 0x00005555577c5fb7 in queue_and_load_dwo_tu (slot=0x60600007fc00, info=0x6210000c34e0) at /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:12674
#3 0x0000555559934232 in htab_traverse_noresize (htab=0x60b000063670, callback=0x5555577c5e61 <queue_and_load_dwo_tu(void**, void*)>, info=0x6210000c34e0)
at /home/simark/src/binutils-gdb/libiberty/hashtab.c:775
#4 0x00005555577c6252 in queue_and_load_all_dwo_tus (per_cu=0x6210000c34e0) at /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:12701
#5 0x000055555777ebd8 in dw2_do_instantiate_symtab (per_cu=0x6210000c34e0, skip_partial=false) at /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:2371
#6 0x000055555777eea2 in dw2_instantiate_symtab (per_cu=0x6210000c34e0, skip_partial=false) at /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:2395
#7 0x0000555557786ab6 in dw2_lookup_symbol (objfile=0x614000007240, block_index=GLOBAL_BLOCK, name=0x602000025310 "main", domain=VAR_DOMAIN)
at /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:3539
After creating the reader object, the reader.cu field should not be
NULL. By checking the commit previous to the faulty one mentioned
above, I noticed that the cu field is normally set by
init_cu_die_reader, called from read_cutu_die_from_dwo, itself called
from cutu_reader::init_tu_and_read_dwo_dies, itself called from
cutu_reader's constructor.
However, cutu_reader::init_tu_and_read_dwo_dies calls
read_cutu_die_from_dwo, passing a pointer to a local `die_reader_specs`
variable. So it's the `cu` field of that object that gets set.
cutu_reader itself is a `die_reader_specs` (it inherits from it), and
the intention was most likely to pass `this` to read_cutu_die_from_dwo.
This way, the fields of the cutu_reader object, which
read_signatured_type will use, are set.
With this, I am able to use:
make check RUNTESTFLAGS='--target_board=fission'
and it looks much better. There are still some failures to be
investigated, but that's the usual state of the testsuite.
gdb/ChangeLog:
* dwarf2/read.c (cutu_reader::init_tu_and_read_dwo_dies): Remove
reader variable, pass `this` to read_cutu_die_from_dwo.
This fixes a regression caused by commit 0d79cdc494d5:
$ make check TESTS="gdb.dwarf2/dw2-ranges-base.exp"
[...]
ERROR: GDB process no longer exists
This error is caused by an abort during the computation of srcpath
when SYMTAB_DIRNAME (s) == NULL.
Computing srcpath only when SYMTAB_DIRNAME (s) is not NULL fixes this
error. Also change the condition for calling debuginfod_source_query
to include whether srcpath could be computed.
gdb/ChangeLog:
2020-02-27 Aaron Merey <amerey@redhat.com>
* source.c (open_source_file): Check for nullptr when computing
srcpath.
I noticed that there's no real reason to have field_info::nfields in
the DWARF reader. It simply mirrors information that is already
available. This patch removes it, in favor of a convenience method.
gdb/ChangeLog
2020-02-27 Tom Tromey <tromey@adacore.com>
* dwarf2/read.c (struct field_info) <nfields>: Now a method, not a
member.
(dwarf2_add_field): Don't update nfields.
(dwarf2_attach_fields_to_type, process_structure_scope): Update.
Use std::abs so that we get the C++ overloaded version that matches
the argument type instead of the C abs function which is only for int
arguments.
There should be no user visible change after this commit.
gdb/ChangeLog:
* gdbtypes.c (create_array_type_with_stride): Use std::abs not
abs.
Include files are represented by a partial symtab, but don't expand to
anything. From dwarf2_psymtab::expand_psymtab:
if (per_cu == NULL)
{
/* It's an include file, no symbols to read for it.
Everything is in the parent symtab. */
readin = true;
return;
}
This patch introduces a new specialization of partial_symtab to handle
this case. In addition to being slightly smaller, I believe an
include file is the only situation where a DWARF psymtab can result in
a null compunit_symtab. This adds an assert to that effect as well.
This change will simplify one of the psymtab sharing patches.
gdb/ChangeLog
2020-02-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (struct dwarf2_include_psymtab): New.
(dwarf2_create_include_psymtab): Use dwarf2_include_psymtab.
(dwarf2_psymtab::expand_psymtab, dwarf2_psymtab::readin_p)
(dwarf2_psymtab::get_compunit_symtab): Remove null checks for
per_cu_data.
dwarf2/index-write.c casts pointers to "dwarf2_psymtab *", but as far
as I can tell, it does not actually use any DWARF-specific fields of
the psymtab. So, this patch changes this code to use partial_symtab
instead. This removes nearly every cast, leaving just the unavoidable
one from addrmap iteration.
gdb/ChangeLog
2020-02-26 Tom Tromey <tom@tromey.com>
* dwarf2/index-write.c (psym_index_map): Change type.
(add_address_entry_worker, write_one_signatured_type)
(recursively_count_psymbols, recursively_write_psymbols)
(class debug_names, psyms_seen_size, write_gdbindex)
(write_debug_names): Use partial_symtab, not dwarf2_psymtab.
Tom Tromey
Tom Tromey
Tom de Vries
Christian Biesinger
Simon Marchi
Kevin Buettner
Andrew Burgess
Simon Marchi
Hannes Domani
John Baldwin
Tankut Baris Aktemur
Luis Machado
Sergio Durigan Junior
Jon Turney
Aaron Merey