[Bug fortran/57598] New: [Coarray,caf] Add FPE-Summary printing (floating-point exception) for STOP/ERROR STOP

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57598

            Bug ID: 57598
           Summary: [Coarray,caf] Add FPE-Summary printing (floating-point
                    exception) for STOP/ERROR STOP
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org

Fortran 2008 demands that the compiler prints a summary of the FPE at
STOP/ERROR STOP.

The patch at http://gcc.gnu.org/ml/fortran/2013-06/msg00077.html adds support
for noncoarrays.

One needs to do likewise for coarrays.

However, as Bill pointed out at
http://mailman.j3-fortran.org/pipermail/j3/2013-June/006458.html, printing on
32k images
  Note: On image n, the following floating-point exception are
        signalling: IEEE_DIVIDE_BY_ZERO
is not a good idea. It's better to collect those statuses and print something
like:
  Note: 1453 images terminated reporting a DIVIDE_BY_ZERO exception, ...


For true multi-image support, one also needs to pass
compile_options.fpe_summary to the CAF library and handle collecting all the
flags (collective SUM reduction). Also STOP has to be handled, not only ERROR
STOP as it is currently done.


Note: Fortran 201x might change the handling, cf. thread at
http://mailman.j3-fortran.org/pipermail/j3/2013-June/006452.html


Simple patch for caf_single:

--- a/libgfortran/caf/single.c
+++ b/libgfortran/caf/single.c
@@ -41,0 +42,3 @@ caf_static_t *caf_static_list = NULL;
+/* Prototype of libgfortran's functions.  */
+void _gfortran_caf_error_stop_str (const char *, int32_t);
+void _gfortran_caf_error_stop (int32_t);
@@ -176,6 +179 @@ _gfortran_caf_error_stop_str (const char *string, int32_t
len)
-  fputs ("ERROR STOP ", stderr);
-  while (len--)
-    fputc (*(string++), stderr);
-  fputs ("\n", stderr);
-
-  exit (1);
+  _gfortran_error_stop_string (string, len);
@@ -188,2 +186 @@ _gfortran_caf_error_stop (int32_t error)
-  fprintf (stderr, "ERROR STOP %d\n", error);
-  exit (error);
+  _gfortran_error_stop_numeric_f08 (error);