This commit changes GDB like this:
- Program received signal SIGINT, Interrupt.
+ Thread 1 "main" received signal SIGINT, Interrupt.
- Breakpoint 1 at 0x40087a: file threads.c, line 87.
+ Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file threads.c, line 87.
... once the program goes multi-threaded. Until GDB sees a second
thread spawn, the output is still the same as before, per the
discussion back in 2012:
https://www.sourceware.org/ml/gdb/2012-11/msg00010.html
This helps non-stop mode, where you can't easily tell which thread hit
a breakpoint or received a signal:
(gdb) info threads
Id Target Id Frame
* 1 Thread 0x7ffff7fc1740 (LWP 19362) "main" (running)
2 Thread 0x7ffff7fc0700 (LWP 19366) "foo" (running)
3 Thread 0x7ffff77bf700 (LWP 19367) "bar" (running)
(gdb)
Program received signal SIGUSR1, User defined signal 1.
0x0000003616a09237 in pthread_join (threadid=140737353877248, thread_return=0x7fffffffd5b8) at pthread_join.c:92
92 lll_wait_tid (pd->tid);
(gdb) b threads.c:87
Breakpoint 1 at 0x40087a: file threads.c, line 87.
(gdb)
Breakpoint 1, thread_function1 (arg=0x1) at threads.c:87
87 usleep (1); /* Loop increment. */
The best the user can do is run "info threads" and try to figure
things out.
It actually also affects all-stop mode, in case of "handle SIG print
nostop":
...
Program received signal SIGUSR1, User defined signal 1.
Program received signal SIGUSR1, User defined signal 1.
Program received signal SIGUSR1, User defined signal 1.
Program received signal SIGUSR1, User defined signal 1.
...
The above doesn't give any clue that these were different threads
getting the SIGUSR1 signal.
I initially thought of lowercasing "breakpoint" in
"Thread 3 hit Breakpoint 1"
but then after trying it I realized that leaving "Breakpoint"
uppercase helps the eye quickly find the relevant information. It's
also easier to implement not showing anything about threads until the
program goes multi-threaded this way.
Here's a larger example session in non-stop mode:
(gdb) c -a&
Continuing.
(gdb) interrupt -a
(gdb)
Thread 1 "main" stopped.
0x0000003616a09237 in pthread_join (threadid=140737353877248, thread_return=0x7fffffffd5b8) at pthread_join.c:92
92 lll_wait_tid (pd->tid);
Thread 2 "foo" stopped.
0x0000003615ebc6ed in nanosleep () at ../sysdeps/unix/syscall-template.S:81
81 T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
Thread 3 "bar" stopped.
0x0000003615ebc6ed in nanosleep () at ../sysdeps/unix/syscall-template.S:81
81 T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
b threads.c:87
Breakpoint 4 at 0x40087a: file threads.c, line 87.
(gdb) b threads.c:67
Breakpoint 5 at 0x400811: file threads.c, line 67.
(gdb) c -a&
Continuing.
(gdb)
Thread 3 "bar" hit Breakpoint 4, thread_function1 (arg=0x1) at threads.c:87
87 usleep (1); /* Loop increment. */
Thread 2 "foo" hit Breakpoint 5, thread_function0 (arg=0x0) at threads.c:68
68 (*myp) ++;
info threads
Id Target Id Frame
* 1 Thread 0x7ffff7fc1740 (LWP 31957) "main" (running)
2 Thread 0x7ffff7fc0700 (LWP 31961) "foo" thread_function0 (arg=0x0) at threads.c:68
3 Thread 0x7ffff77bf700 (LWP 31962) "bar" thread_function1 (arg=0x1) at threads.c:87
(gdb) shell kill -SIGINT 31957
(gdb)
Thread 1 "main" received signal SIGINT, Interrupt.
0x0000003616a09237 in pthread_join (threadid=140737353877248, thread_return=0x7fffffffd5b8) at pthread_join.c:92
92 lll_wait_tid (pd->tid);
info threads
Id Target Id Frame
* 1 Thread 0x7ffff7fc1740 (LWP 31957) "main" 0x0000003616a09237 in pthread_join (threadid=140737353877248, thread_return=0x7fffffffd5b8) at pthread_join.c:92
2 Thread 0x7ffff7fc0700 (LWP 31961) "foo" thread_function0 (arg=0x0) at threads.c:68
3 Thread 0x7ffff77bf700 (LWP 31962) "bar" thread_function1 (arg=0x1) at threads.c:87
(gdb) t 2
[Switching to thread 2, Thread 0x7ffff7fc0700 (LWP 31961)]
#0 thread_function0 (arg=0x0) at threads.c:68
68 (*myp) ++;
(gdb) catch syscall
Catchpoint 6 (any syscall)
(gdb) c&
Continuing.
(gdb)
Thread 2 "foo" hit Catchpoint 6 (call to syscall nanosleep), 0x0000003615ebc6ed in nanosleep () at ../sysdeps/unix/syscall-template.S:81
81 T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
I'll work on documentation next if this looks agreeable.
This patch applies on top of the star wildcards thread IDs series:
https://sourceware.org/ml/gdb-patches/2016-01/msg00291.html
For convenience, I've pushed this to the
users/palves/show-which-thread-caused-stop branch.
gdb/doc/ChangeLog:
2016-01-18 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Threads): Mention that GDB displays the ID and name
of the thread that hit a breakpoint or received a signal.
gdb/ChangeLog:
2016-01-18 Pedro Alves <palves@redhat.com>
* NEWS: Mention that GDB now displays the ID and name of the
thread that hit a breakpoint or received a signal.
* break-catch-sig.c (signal_catchpoint_print_it): Use
maybe_print_thread_hit_breakpoint.
* break-catch-syscall.c (print_it_catch_syscall): Likewise.
* break-catch-throw.c (print_it_exception_catchpoint): Likewise.
* breakpoint.c (maybe_print_thread_hit_breakpoint): New function.
(print_it_catch_fork, print_it_catch_vfork, print_it_catch_solib)
(print_it_catch_exec, print_it_ranged_breakpoint)
(print_it_watchpoint, print_it_masked_watchpoint, bkpt_print_it):
Use maybe_print_thread_hit_breakpoint.
* breakpoint.h (maybe_print_thread_hit_breakpoint): Declare.
* gdbthread.h (show_thread_that_caused_stop): Declare.
* infrun.c (print_signal_received_reason): Print which thread
received signal.
* thread.c (show_thread_that_caused_stop): New function.
gdb/testsuite/ChangeLog:
2016-01-18 Pedro Alves <palves@redhat.com>
* gdb.base/async-shell.exp: Adjust expected output.
* gdb.base/dprintf-non-stop.exp: Adjust expected output.
* gdb.base/siginfo-thread.exp: Adjust expected output.
* gdb.base/watchpoint-hw-hit-once.exp: Adjust expected output.
* gdb.java/jnpe.exp: Adjust expected output.
* gdb.threads/clone-new-thread-event.exp: Adjust expected output.
* gdb.threads/continue-pending-status.exp: Adjust expected output.
* gdb.threads/leader-exit.exp: Adjust expected output.
* gdb.threads/manythreads.exp: Adjust expected output.
* gdb.threads/pthreads.exp: Adjust expected output.
* gdb.threads/schedlock.exp: Adjust expected output.
* gdb.threads/siginfo-threads.exp: Adjust expected output.
* gdb.threads/signal-command-multiple-signals-pending.exp: Adjust
expected output.
* gdb.threads/signal-delivered-right-thread.exp: Adjust expected
output.
* gdb.threads/sigthread.exp: Adjust expected output.
* gdb.threads/watchpoint-fork.exp: Adjust expected output.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
* gdb.java/jprint.exp: Don't rely on inferior output, but instead
look at the funtions' returns.
* gdb.java/jprint.java (jvclass.addprint, jprint.print(int))
(jprint.print(int, int)): Change return type to int. Adjust.
Stop on first linespec terminator instead of eating what we can.
* linespec.c (is_linespec_boundary): New function.
(name_end): Remove function.
(keep_name_info): New parameter on_boundary, replace the body.
(decode_line_1): Provide the parameter to keep_name_info.
(decode_compound): Likewise. Drop the trailing java return type
handling. Twice.
gdb/testsuite/
Stop on first linespec terminator instead of eating what we can.
* gdb.cp/minsym-fallback-main.cc (main): Call also C::operator ().
* gdb.cp/minsym-fallback.cc (C::operator ()): Define.
* gdb.cp/minsym-fallback.exp (break 'C::f()'): Change to ...
(break C::f()): ... this one.
(break C::operator()()): New test.
* gdb.cp/minsym-fallback.h (C::operator ()): Declare.
* gdb.java/jmisc.exp (break jmisc.main(java.lang.String[])int): New
test.
* gdb.base/printcmds.exp (test_float_accepted): Import gdb_prompt.
Move here, negate and extend by XFAIL the "p 0x1.1" test from ...
(test_float_rejected): ... here.
* gdb.java/jv-print.exp (test_float_accepted): Import gdb_prompt.
Move here, negate and extend by XFAIL the "p 0x1.1" test from ...
(test_float_rejected): ... here.
* gdb.objc/print.exp (test_float_accepted): Import gdb_prompt.
Move here, negate and extend by XFAIL the "p 0x1.1" test from ...
(test_float_rejected): ... here.
* gdb.pascal/print.exp (test_float_accepted): Import gdb_prompt.
Move here, negate and extend by XFAIL the "p 0x1.1" test from ...
(test_float_rejected): ... here.
* gdb.base/callfuncs.exp (set_lang_c): Delete, set c language directly.
* gdb.base/printcmds.exp (set_lang_c): Delete, set c language directly.
Simplify, early exit if runto_main fails.
* gdb.fortran/exprs.exp: load_lib fortran.exp.
(set_lang_fortran): Moved to lib/fortran.exp.
* gdb.fortran/types.exp: load_lib fortran.exp.
(set_lang_fortran): Moved to lib/fortran.exp.
* gdb.java/jmisc.exp (set_lang_java): Moved to lib/java.exp.
* gdb.java/jprint.exp (set_lang_java): Ditto.
* gdb.java/jv-exp.exp: load_lib java.exp.
If set_lang_java fails, issue a warning instead of failure to be
consistent with other set_lang_foo uses.
(set_lang_java): Moved to lib/java.exp.
* gdb.java/jv-print.exp (set_lang_java): Moved to lib/java.exp.
If set_lang_java fails, issue a warning instead of failure to be
consistent with other set_lang_foo uses.
* gdb.pascal/types.exp: load_lib pascal.exp.
(set_lang_pascal): Moved to lib/pascal.exp.
* lib/fortran.exp: New file.
* lib/java.exp (set_lang_java): New function.
* lib/pascal.exp (set_lang_pascal): New function.
* gdb.cp/cplusfuncs.cc (dm_type_short): New function.
(dm_type_long): New function.
(dm_type_unsigned_short): New function.
(dm_type_unsigned_long): New function.
(myint): New typedef.
* gdb.cp/cplusfuncs.exp (probe_demangler): Add tests for short,
long, unsigned shor and long, operator char*, and typedef.
(test_lookup_operator_functions): Add operator char* test.
(test_paddr_operator_functions): Likewise.
(test_paddr_overloaded_functions): Use probe values for
short, long, and unsigned short and long.
(test_paddr_hairy_functions): If the demangler probe detected
gdb type printers, "expect" them. Otherwise "expect" the v2 or v3
demangler.
* gdb.cp/expand-sals.exp: Backtrace may contain class names.
* gdb.cp/member-ptr.exp: Refine expected result for "print pmf"
and "print null_pmf".
Add test "ptype a.*pmf".
* gdb.cp/overload.exp: Allow optional "int" to appear with
"short" and "long".
* gdb.cp/ovldbreak.exp: Use append to construct super-duper
long expect value for men_overload1arg.
Allow "int" to appear with "short" and "long".
When testing "info break", add argument for main (void).
Also allow "int" to appear with "short" and "long".
Ditto with "unsigned" and "long long".
* gdb.java/jmain.exp: Do not enclose methods names in single
quotes.
* gdb.java/jmisc.exp: Likewise.
* gdb.java/jprint.exp: Likewise.
* gdb.python/py-symbol.exp: Update expected "linkage_name" value.
From Jan Kratochvil <jan.kratochvil@redhat.com>:
* gdb.cp/exception.exp (backtrace after first throw)
(backtrace after second throw): Allow a namespace before __cxa_throw.
(backtrace after first catch, backtrace after second catch): Allow
a namespace before __cxa_begin_catch.
* gdb.cp/cpexprs.exp: New file.
* gdb.cp/cpexprs.cc: New file.
From Daniel Jacobowitz <dan@codesourcery.com>
* gdb.cp/cpexprs.exp (escape): Delete. Change all callers
to use string_to_regexp.
(ctor, dtor): New functions. Use them to match constructor
and destructor function types.
(Top level): Use runto_main.
* gdb.base/annota3.exp: Likewise.
* gdb.base/sigstep.exp (advancei): Fail if we hit the breakpoint
again (instead of timing out).
* gdb.gdb/selftest.exp (do_steps_and_nexts): Add an XFAIL for
GCC bug 26475.
* gdb.java/jmisc.exp: Adjust to work with method signatures including
return types. Add kfails for GDB bugs 2214 and 2215. Move exit
test from jmisc1.exp.
* gdb.java/jmisc1.exp: Delete.
* gdb.java/jprint.exp: Adjust to work with method signatures including
return types.
* gdb.objc/basicclass.exp: Update for gobjc 4.1 debug info.
* gdb.threads/linux-dp.exp: Don't be confused by program output.
* lib/java.exp (compile_java_from_source): Pass the correct type
to target_compile.
* gdb.java/jmain.exp: Fix expected line number for main to
break at. Set XFAIL for break at main test since gcj does not
provide line number info for first statement in main.