fortran: dynamically allocate error_buffer [PR117442]

PR fortran/117442 reports a crash on exit of f951 when configured
with --enable-gather-detailed-mem-stats.

The crash happens if any diagnostics were ever buffered into
error_buffer.  The root cause is that error_buffer is statically
allocated and thus has a non-trivial destructor called at exit.
If error_buffer's diagnostic_buffer ever buffered anything, then
a diagnostic_per_format_buffer will have been created for the
buffer per-output-sink, and the destructors for these call
into the mem-stats subsystem, which has already beeen cleaned up.

The simplest fix is to allocate error_buffer on the heap, rather
that statically, which fixes the crash.

There's a comment about error_buffer:

  /* pp_error_buffer is statically allocated.  This simplifies memory
     management when using gfc_push/pop_error. */

added by Manu in r6-1748-g5862c189c2c3c2 while fixing PR fortran/66528.
The comment appears to be out of date.  I've tested maxerrors.f90 under
valgrind, and it's clean with the patch.

gcc/fortran/ChangeLog:
	PR fortran/117442
	* error.cc (error_buffer): Convert to a pointer so it can be
	heap-allocated.
	(gfc_error_now): Update for error_buffer being heap-allocated.
	(gfc_clear_error): Likewise.
	(gfc_error_flag_test): Likewise.
	(gfc_error_check): Likewise.
	(gfc_push_error): Likewise.
	(gfc_pop_error): Likewise.
	(gfc_diagnostics_init): Allocate error_buffer on the heap, rather
	than statically.
	(gfc_diagnostics_finish): Delete error_buffer.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

0 files changed, 0 insertions, 0 deletions