Give more-useful info on a fatal error (Bug#12328).

* doc/emacs/trouble.texi (Crashing): New section, documenting this.
* etc/NEWS: Document the change.
* src/alloc.c [ENABLE_CHECKING]: Do not include <execinfo.h>.
(die) [ENABLE_CHECKING]: Call fatal_error_backtrace instead
of doing the work ourselves.
* src/emacs.c (fatal_error_signal): Let fatal_error_backtrace
do most of the work.
(fatal_error_backtrace): New function, taken from the guts
of the old fatal_error_signal, but with a new option to output
a backtrace.
(shut_down_emacs) [!DOS_NT]: Use strsignal to give more-useful
info about the signal than just its number.
* src/lisp.h (fatal_error_backtrace, emacs_backtrace): New decls.
* src/sysdep.c: Include <execinfo.h>
(emacs_backtrace): New function, taken partly from the previous
code of the 'die' function.
(emacs_abort): Call fatal_error_backtrace rather than abort.

1 files changed, 1 insertions, 8 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 2a831cea62a..157d3a1d799 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -6685,21 +6685,14 @@ which_symbols (Lisp_Object obj, EMACS_INT find_max)
 
 #ifdef ENABLE_CHECKING
 
-# include <execinfo.h>
-
 bool suppress_checking;
 
 void
 die (const char *msg, const char *file, int line)
 {
-  enum { NPOINTERS_MAX = 500 };
-  void *buffer[NPOINTERS_MAX];
-  int npointers;
   fprintf (stderr, "\r\n%s:%d: Emacs fatal error: %s\r\n",
            file, line, msg);
-  npointers = backtrace (buffer, NPOINTERS_MAX);
-  backtrace_symbols_fd (buffer, npointers, STDERR_FILENO);
-  emacs_abort ();
+  fatal_error_backtrace (SIGABRT, INT_MAX);
 }
 #endif