diff options
| -rw-r--r-- | gdb/ChangeLog | 12 | ||||
| -rw-r--r-- | gdb/cp-support.c | 9 | ||||
| -rw-r--r-- | gdb/event-top.c | 23 | ||||
| -rw-r--r-- | gdb/event-top.h | 19 |
4 files changed, 51 insertions, 12 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index f6732b8..0157dea 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2021-03-12 Christian Biesinger <cbiesinger@google.com> + + PR threads/27239 + * cp-support.c: Use scoped_segv_handler_restore. + * event-top.c (thread_local_segv_handler): Made static. + (scoped_segv_handler_restore::scoped_segv_handler_restore): + New function. + (scoped_segv_handler_restore::~scoped_segv_handler_restore): New + function. + * event-top.h (class scoped_segv_handler_restore): New class. + (thread_local_segv_handler): Removed. + 2021-03-10 Tom Tromey <tromey@adacore.com> * parser-defs.h (parser_state): Change completion to bool. diff --git a/gdb/cp-support.c b/gdb/cp-support.c index 1abc3e2..fb4e428 100644 --- a/gdb/cp-support.c +++ b/gdb/cp-support.c @@ -1615,11 +1615,10 @@ gdb_demangle (const char *name, int options) int crash_signal = 0; #ifdef HAVE_WORKING_FORK - scoped_restore restore_segv - = make_scoped_restore (&thread_local_segv_handler, - catch_demangler_crashes - ? gdb_demangle_signal_handler - : nullptr); + scoped_segv_handler_restore restore_segv + (catch_demangler_crashes + ? gdb_demangle_signal_handler + : nullptr); bool core_dump_allowed = gdb_demangle_attempt_core_dump; SIGJMP_BUF jmp_buf; diff --git a/gdb/event-top.c b/gdb/event-top.c index a33f642..fb0df94 100644 --- a/gdb/event-top.c +++ b/gdb/event-top.c @@ -850,9 +850,17 @@ gdb_readline_no_editing_callback (gdb_client_data client_data) } -/* See event-top.h. */ +/* The SIGSEGV handler for this thread, or NULL if there is none. GDB + always installs a global SIGSEGV handler, and then lets threads + indicate their interest in handling the signal by setting this + thread-local variable. -thread_local void (*thread_local_segv_handler) (int); + This is a static variable instead of extern because on various platforms + (notably Cygwin) extern thread_local variables cause link errors. So + instead, we have scoped_segv_handler_restore, which also makes it impossible + to accidentally forget to restore it to the original value. */ + +static thread_local void (*thread_local_segv_handler) (int); static void handle_sigsegv (int sig); @@ -1288,6 +1296,17 @@ gdb_disable_readline (void) delete_file_handler (ui->input_fd); } +scoped_segv_handler_restore::scoped_segv_handler_restore (segv_handler_t new_handler) +{ + m_old_handler = thread_local_segv_handler; + thread_local_segv_handler = new_handler; +} + +scoped_segv_handler_restore::~scoped_segv_handler_restore() +{ + thread_local_segv_handler = m_old_handler; +} + static const char debug_event_loop_off[] = "off"; static const char debug_event_loop_all_except_ui[] = "all-except-ui"; static const char debug_event_loop_all[] = "all"; diff --git a/gdb/event-top.h b/gdb/event-top.h index c52826e..b036f13 100644 --- a/gdb/event-top.h +++ b/gdb/event-top.h @@ -70,10 +70,19 @@ extern void gdb_rl_callback_handler_install (const char *prompt); currently installed. */ extern void gdb_rl_callback_handler_reinstall (void); -/* The SIGSEGV handler for this thread, or NULL if there is none. GDB - always installs a global SIGSEGV handler, and then lets threads - indicate their interest in handling the signal by setting this - thread-local variable. */ -extern thread_local void (*thread_local_segv_handler) (int); +typedef void (*segv_handler_t) (int); + +/* On construction, replaces the current thread's SIGSEGV handler with + the provided one. On destruction, restores the handler to the + original one. */ +class scoped_segv_handler_restore +{ + public: + scoped_segv_handler_restore (segv_handler_t new_handler); + ~scoped_segv_handler_restore (); + + private: + segv_handler_t m_old_handler; +}; #endif |