From f0e8c4c5d1bce422ac86090b76c28931b0d240bf Mon Sep 17 00:00:00 2001 From: Jan Kratochvil Date: Thu, 22 Jan 2015 21:02:24 +0100 Subject: [PATCH] Print current thread after loading a core file downstream Fedora request: Please make it easier to find the backtrace of the crashing thread https://bugzilla.redhat.com/show_bug.cgi?id=1024504 Currently after loading a core file GDB prints: Core was generated by `./threadcrash1'. Program terminated with signal SIGSEGV, Segmentation fault. 8 *(volatile int *)0=0; (gdb) _ there is nowhere seen which of the threads had crashed. In reality GDB always numbers that thread as #1 and it is the current thread that time. But after dumping all the info into a file for later analysis it is no longer obvious. 'thread apply all bt' even puts the thread #1 to the _end_ of the output!!! Should GDB always print after loading a core file what "thread" command would print? [Current thread is 1 (Thread 0x7fcbe28fe700 (LWP 15453))] BTW I think it will print the thread even when loading single/non-threaded core file when other inferior(s) exist. But that currently crashes [Bug threads/12074] multi-inferior internal error https://sourceware.org/bugzilla/show_bug.cgi?id=12074 plus I think that would be a correct behavior anyway. gdb/ChangeLog 2015-01-22 Jan Kratochvil * corelow.c (core_open): Call also thread_command. * gdbthread.h (thread_command): New prototype moved from ... * thread.c (thread_command): ... here. (thread_command): Make it global. --- gdb/ChangeLog | 7 +++++++ gdb/corelow.c | 13 +++++++++++++ gdb/gdbthread.h | 2 ++ gdb/thread.c | 3 +-- 4 files changed, 23 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 6e3e2581e45..8d9e367beb4 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2015-01-22 Jan Kratochvil + + * corelow.c (core_open): Call also thread_command. + * gdbthread.h (thread_command): New prototype moved from ... + * thread.c (thread_command): ... here. + (thread_command): Make it global. + 2015-01-22 Pedro Alves * configure.ac [*mingw32*]: Check $curses_found instead of diff --git a/gdb/corelow.c b/gdb/corelow.c index a9eadd565f0..6a67a989f58 100644 --- a/gdb/corelow.c +++ b/gdb/corelow.c @@ -456,6 +456,19 @@ core_open (const char *arg, int from_tty) /* Now, set up the frame cache, and print the top of stack. */ reinit_frame_cache (); print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1); + + /* Current thread should be NUM 1 but the user does not know that. + If a program is single threaded gdb in general does not mention + anything about threads. That is why the test is >= 2. */ + if (thread_count () >= 2) + { + TRY_CATCH (except, RETURN_MASK_ERROR) + { + thread_command (NULL, from_tty); + } + if (except.reason < 0) + exception_print (gdb_stderr, except); + } } static void diff --git a/gdb/gdbthread.h b/gdb/gdbthread.h index 15a979b1197..a2f378ae8a3 100644 --- a/gdb/gdbthread.h +++ b/gdb/gdbthread.h @@ -455,6 +455,8 @@ extern void finish_thread_state_cleanup (void *ptid_p); /* Commands with a prefix of `thread'. */ extern struct cmd_list_element *thread_cmd_list; +extern void thread_command (char *tidstr, int from_tty); + /* Print notices on thread events (attach, detach, etc.), set with `set print thread-events'. */ extern int print_thread_events; diff --git a/gdb/thread.c b/gdb/thread.c index ed20fbeca5a..4bce2120570 100644 --- a/gdb/thread.c +++ b/gdb/thread.c @@ -62,7 +62,6 @@ static int highest_thread_num; spawned new threads we haven't heard of yet. */ static int threads_executing; -static void thread_command (char *tidstr, int from_tty); static void thread_apply_all_command (char *, int); static int thread_alive (struct thread_info *); static void info_threads_command (char *, int); @@ -1506,7 +1505,7 @@ thread_apply_command (char *tidlist, int from_tty) /* Switch to the specified thread. Will dispatch off to thread_apply_command if prefix of arg is `apply'. */ -static void +void thread_command (char *tidstr, int from_tty) { if (!tidstr) -- 2.30.2