When building GDB with clang 16, I got this,
CXX maint.o
maint.c:1045:23: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
m_space_enabled = 1;
^ ~
maint.c:1057:22: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
m_time_enabled = 1;
^ ~
maint.c:1073:24: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
m_symtab_enabled = 1;
^ ~
3 errors generated.
Work around this by using bool bitfields instead.
Tested by rebuilding on x86_64-linux with clang 16 and gcc 12.
Approved-By: Tom Tromey <tom@tromey.com>
This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
Consider test-case test.c:
...
int main (void) {
void *p = malloc (10);
return 0;
}
...
When compiled to a non-PIE exec:
...
$ gcc -m32 test.c
...
the call sequence looks like:
...
8048447: 83 ec 0c sub $0xc,%esp
804844a: 6a 0a push $0xa
804844c: e8 bf fe ff ff call 8048310 <malloc@plt>
...
which calls to:
...
08048310 <malloc@plt>:
8048310: ff 25 0c a0 04 08 jmp *0x804a00c
8048316: 68 00 00 00 00 push $0x0
804831b: e9 e0 ff ff ff jmp 8048300 <.plt>
...
where the first insn at 0x8048310 initially jumps to the following address
0x8048316, read from the .got.plt @ 0x804a00c:
...
804a000 0c9f0408 00000000 00000000 16830408 ................
804a010 26830408 &...
...
Likewise, when compiled as a PIE:
...
$ gcc -m32 -fPIE -pie test.c
...
we have this call sequence (with %ebx setup to point to the .got.plt):
...
0000055d <main>:
579: 83 ec 0c sub $0xc,%esp
57c: 6a 0a push $0xa
57e: 89 c3 mov %eax,%ebx
580: e8 6b fe ff ff call 3f0 <malloc@plt>
...
which calls to:
...
000003f0 <malloc@plt>:
3f0: ff a3 0c 00 00 00 jmp *0xc(%ebx)
3f6: 68 00 00 00 00 push $0x0
3fb: e9 e0 ff ff ff jmp 3e0 <.plt>
...
where the insn at 0x3f0 initially jumps to following address 0x3f6, read from
the .got.plt at offset 0xc:
...
2000 f41e0000 00000000 00000000 f6030000 ................
2010 06040000 ....
...
When instead doing an inferior call to malloc (with nosharedlib to force
malloc to resolve to malloc@plt rather than the functions in ld.so or libc.so)
with the non-PIE exec, we have the expected:
...
$ gdb -q -batch a.out -ex start -ex nosharedlib -ex "p /x (void *)malloc (10)"
Temporary breakpoint 1 at 0x8048444
Temporary breakpoint 1, 0x08048444 in main ()
$1 = 0x804b160
...
But with the PIE exec, we run into:
...
$ gdb -q -batch a.out -ex start -ex nosharedlib -ex "p /x (void *)malloc (10)"
Temporary breakpoint 1 at 0x56c
Temporary breakpoint 1, 0x5655556c in main ()
Program received signal SIGSEGV, Segmentation fault.
0x565553f0 in malloc@plt ()
...
The segfault happens because:
- the inferior call mechanism doesn't setup %ebx
- %ebx instead is 0
- the jump to "*0xc(%ebx)" reads from memory at 0xc
Fix this by setting up %ebx properly in i386_thiscall_push_dummy_call.
Fixes this failure with target board unix/-m32/-pie/-fPIE reported in
PR28467:
...
FAIL: gdb.base/nodebug.exp: p/c (int) array_index("abcdef",2)
...
Tested on x86_64-linux, with target board unix/-m32 and unix/-m32/-fPIE/-pie.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28467
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
This reverts commit 62e77f56f0ce8b10122881d8f0acd70e113fde93.
(except for ChangeLog and a bugfix in minimal_symbol_reader::install)
As agreed on the mailing list, now that GDB 9 has branched, this patch
reverts the change to set worker-threads to zero. After this patch,
multithreaded minsym demangling will be enabled again by default.
gdb/ChangeLog:
2019-12-13 Christian Biesinger <cbiesinger@google.com>
* maint.c (n_worker_threads): Default to -1.
(worker_threads_disabled): Remove function.
* maint.h (worker_threads_disabled): Remove function.
* minsyms.c (minimal_symbol_reader::record_full): Don't call
symbol_set_names here if worker_threads_disabled () is true.
Change-Id: I5ff3e318d96f60968c8b8bedb84546ad2314d94b
Per discussion on gdb-patches with Joel, this patch turns off multihreaded
symbol loading by default. It can be turned on using:
maint set worker-threads unlimited
To keep the behavior as close as possible to the old code, it still
calls symbol_set_names in the old place if n_worker_threads is 0.
gdb/ChangeLog:
2019-11-27 Christian Biesinger <cbiesinger@google.com>
* maint.c (n_worker_threads): Default to 0.
(worker_threads_disabled): New function.
* maint.h (worker_threads_disabled): New function.
* minsyms.c (minimal_symbol_reader::record_full): Call symbol_set_names
here if worker_threads_disabled () is true.
(minimal_symbol_reader::install): Skip all threading if
worker_threads_disabled () is true.
Change-Id: I92ba4f6bbf07363189666327cad452d6b9c8e01d
Currently "maint time" will print the amount of time a command took.
Sometimes, though, it's useful to have a timestamp as well -- for
example if one is correlating a gdb log with some other log.
This patch adds a timestamp to the start and end of each command when
this setting is in effect.
This also removes a "//" comment and changes scoped_command_stats to
use DISABLE_COPY_AND_ASSIGN; two minor things I noticed while working
on the patch.
Tested on x86-64 Fedora 29.
gdb/ChangeLog
2019-06-06 Tom Tromey <tromey@adacore.com>
* maint.h (class scoped_command_stats): Use
DISABLE_COPY_AND_ASSIGN.
<print_time>: New method.
* maint.c (scoped_command_stats, ~scoped_command_stats): Call
print_time.
(scoped_command_stats::print_time): New method.
gdb/testsuite/ChangeLog
2019-06-06 Tom Tromey <tromey@adacore.com>
* gdb.base/maint.exp: Expect command started/finished output.
This commit applies all changes made after running the gdb/copyright.py
script.
Note that one file was flagged by the script, due to an invalid
copyright header
(gdb/unittests/basic_string_view/element_access/char/empty.cc).
As the file was copied from GCC's libstdc++-v3 testsuite, this commit
leaves this file untouched for the time being; a patch to fix the header
was sent to gcc-patches first.
gdb/ChangeLog:
Update copyright year range in all GDB files.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
This patch fixes a few problems with GDB's time handling.
#1 - It avoids problems with gnulib's C++ namespace support
On MinGW, the struct timeval that should be passed to gnulib's
gettimeofday replacement is incompatible with libiberty's
timeval_sub/timeval_add. That's because gnulib also replaces "struct
timeval" with its own definition, while libiberty expects the
system's.
E.g., in code like this:
gettimeofday (&prompt_ended, NULL);
timeval_sub (&prompt_delta, &prompt_ended, &prompt_started);
timeval_add (&prompt_for_continue_wait_time,
&prompt_for_continue_wait_time, &prompt_delta);
That's currently handled in gdb by not using gnulib's gettimeofday at
all (see common/gdb_sys_time.h), but that #undef hack won't work with
if/when we enable gnulib's C++ namespace support, because that mode
adds compile time warnings for uses of ::gettimeofday, which are hard
errors with -Werror.
#2 - But there's an elephant in the room: gettimeofday is not monotonic...
We're using it to:
a) check how long functions take, for performance analysis
b) compute when in the future to fire events in the event-loop
c) print debug timestamps
But that's exactly what gettimeofday is NOT meant for. Straight from
the man page:
~~~
The time returned by gettimeofday() is affected by
discontinuous jumps in the system time (e.g., if the system
administrator manually changes the system time). If you need a
monotonically increasing clock, see clock_gettime(2).
~~~
std::chrono (part of the C++11 standard library) has a monotonic clock
exactly for such purposes (std::chrono::steady_clock). This commit
switches to use that instead of gettimeofday, fixing all the issues
mentioned above.
gdb/ChangeLog:
2016-11-23 Pedro Alves <palves@redhat.com>
* Makefile.in (SFILES): Add common/run-time-clock.c.
(HFILES_NO_SRCDIR): Add common/run-time-clock.h.
(COMMON_OBS): Add run-time-clock.o.
* common/run-time-clock.c, common/run-time-clock.h: New files.
* defs.h (struct timeval, print_transfer_performance): Delete
declarations.
* event-loop.c (struct gdb_timer) <when>: Now a
std::chrono::steady_clock::time_point.
(create_timer): use std::chrono::steady_clock instead of
gettimeofday. Use new instead of malloc.
(delete_timer): Use delete instead of xfree.
(duration_cast_timeval): New.
(update_wait_timeout): Use std::chrono::steady_clock instead of
gettimeofday.
* maint.c: Include <chrono> instead of "gdb_sys_time.h", <time.h>
and "timeval-utils.h".
(scoped_command_stats::~scoped_command_stats)
(scoped_command_stats::scoped_command_stats): Use
std::chrono::steady_clock instead of gettimeofday. Use
user_cpu_time_clock instead of get_run_time.
* maint.h: Include "run-time-clock.h" and <chrono>.
(scoped_command_stats): <m_start_cpu_time>: Now a
user_cpu_time_clock::time_point.
<m_start_wall_time>: Now a std::chrono::steady_clock::time_point.
* mi/mi-main.c: Include "run-time-clock.h" and <chrono> instead of
"gdb_sys_time.h" and <sys/resource.h>.
(rusage): Delete.
(mi_execute_command): Use new instead of XNEW.
(mi_load_progress): Use std::chrono::steady_clock instead of
gettimeofday.
(timestamp): Rewrite in terms of std::chrono::steady_clock,
user_cpu_time_clock and system_cpu_time_clock.
(timeval_diff): Delete.
(print_diff): Adjust to use std::chrono::steady_clock,
user_cpu_time_clock and system_cpu_time_clock.
* mi/mi-parse.h: Include "run-time-clock.h" and <chrono> instead
of "gdb_sys_time.h".
(struct mi_timestamp): Change fields types to
std::chrono::steady_clock::time_point, user_cpu_time_clock::time
and system_cpu_time_clock::time_point, instead of struct timeval.
* symfile.c: Include <chrono> instead of <time.h> and
"gdb_sys_time.h".
(struct time_range): New.
(generic_load): Use std::chrono::steady_clock instead of
gettimeofday.
(print_transfer_performance): Replace timeval parameters with a
std::chrono::steady_clock::duration parameter. Adjust.
* utils.c: Include <chrono> instead of "timeval-utils.h",
"gdb_sys_time.h", and <time.h>.
(prompt_for_continue_wait_time): Now a
std::chrono::steady_clock::duration.
(defaulted_query, prompt_for_continue): Use
std::chrono::steady_clock instead of
gettimeofday/timeval_sub/timeval_add.
(reset_prompt_for_continue_wait_time): Use
std::chrono::steady_clock::duration instead of struct timeval.
(get_prompt_for_continue_wait_time): Return a
std::chrono::steady_clock::duration instead of struct timeval.
(vfprintf_unfiltered): Use std::chrono::steady_clock instead of
gettimeofday. Use std::string. Use '.' instead of ':'.
* utils.h: Include <chrono>.
(get_prompt_for_continue_wait_time): Return a
std::chrono::steady_clock::duration instead of struct timeval.
gdb/gdbserver/ChangeLog:
2016-11-23 Pedro Alves <palves@redhat.com>
* debug.c: Include <chrono> instead of "gdb_sys_time.h".
(debug_vprintf): Use std::chrono::steady_clock instead of
gettimeofday. Use '.' instead of ':'.
* tracepoint.c: Include <chrono> instead of "gdb_sys_time.h".
(get_timestamp): Use std::chrono::steady_clock instead of
gettimeofday.
This removes make_command_stats_cleanup in favor of an RAII class.
The patch is reasonably straightforward, but keeping the same
semantics without excessive reindentation required splitting
captured_main in two.
2016-10-21 Tom Tromey <tom@tromey.com>
* maint.h (scoped_command_stats): New class.
(make_command_stats_cleanup): Don't declare.
* maint.c (struct cmd_stats): Remove.
(~scoped_command_stats): Rename from report_command_stats. Now a
destructor.
(scoped_command_stats): Rename from make_command_stats_cleanup.
Now a constructor.
* main.c (captured_main_1): New function. Use
scoped_command_stats.
(captured_main): Call captured_main_1.
* event-top.c (command_handler): Use scoped_command_stats.
* NEWS: Add entry.
* event-top.c: #include "maint.h".
* main.c: #include "maint.h".
* maint.c: #include <sys/time.h>, <time.h>, block.h, top.h,
timeval-utils.h, maint.h, cli/cli-setshow.h.
(per_command_time, per_command_space): New static globals.
(per_command_symtab): New static global.
(per_command_setlist, per_command_showlist): New static globals.
(struct cmd_stats): Move here from utils.c.
(set_per_command_time): Renamed from set_display_time in utils.c
and moved here. All callers updated.
(set_per_command_space): Renamed from set_display_space in utils.c
and moved here. All callers updated.
(count_symtabs_and_blocks): New function.
(report_command_stats): Moved here from utils.c. Add support for
printing symtab stats. Only print data if enabled before command
executed.
(make_command_stats_cleanup): Ditto.
(sert_per_command_cmd, show_per_command_cmd): New functions.
(_initialize_maint_cmds): Add new commands
mt set per-command {space,time,symtab} {on,off}.
* maint.h: New file.
* top.c: #include "maint.h".
* utils.c (reset_prompt_for_continue_wait_time): New function.
(get_prompt_for_continue_wait_time): New function.
* utils.h (reset_prompt_for_continue_wait_time): Declare
(get_prompt_for_continue_wait_time): Declare.
(make_command_stats_cleanup): Moved to maint.h.
(set_display_time, set_display_space): Moved to maint.h and renamed
to set_per_command_time, set_per_command_space.
* cli/cli-setshow.c (parse_cli_boolean_value): Renamed from
parse_binary_operation and made non-static. Don't call error,
just return an error marker. All callers updated.
* cli/cli-setshow.h (parse_cli_boolean_value): Declare.
doc/
* gdb.texinfo (Maintenance Commands): Add docs for
"mt set per-command {space,time,symtab} {on,off}".
testsuite/
* gdb.base/maint.exp: Update tests for per-command stats.
