https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67758
--- Comment #3 from Steve Kargl <sgk at troutmask dot apl.washington.edu> --- On Tue, Sep 29, 2015 at 07:56:16PM +0000, kargl at gcc dot gnu.org wrote: > > troutmask:sgk[204] gfc6 -c r5.f > f951: internal compiler error: Segmentation fault > no stack trace because unwind library not available > Please submit a full bug report, > with preprocessed source if appropriate. > See <http://gcc.gnu.org/bugs.html> for instructions. This fixes the regression. Index: symbol.c =================================================================== --- symbol.c (revision 228264) +++ symbol.c (working copy) @@ -3211,6 +3211,8 @@ gfc_restore_last_undo_checkpoint (void) while (csym != p) { + if (!csym) + goto syntax; cparent = csym; csym = csym->common_next; } @@ -3242,6 +3244,11 @@ gfc_restore_last_undo_checkpoint (void) if (!single_undo_checkpoint_p ()) pop_undo_change_set (latest_undo_chgset); + + return; + +syntax: + gfc_error ("syntax or semantics issue at %C"); } But, the real issue is that the second COMMON is not allowed to appear in the execution block of a program. gfortran should probably error out earlier.
