https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66707
Bug ID: 66707 Summary: Endless compilation on wrong usage of common Product: gcc Version: 5.1.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: gerhard.steinmetz.fort...@t-online.de Target Milestone: --- After printing some correct and helpful error messages, compilation of the following snippets (wrong code) will not end. Tested with gfortran 5.1.1, 4.9.0, 4.8.3 (on SUSE Linux 13.2, 64 bit). $ cat zlctc_1.f90 program p c = 1 common // c common // c end $ cat zlctc_2.f90 program p integer, pointer :: a common a, a common a end $ cat zlctc_3.f90 program p integer, pointer :: a common a => null() common a => null() end $ time gfortran zlctc_1.f90 zlctc_1.f90:3.14: common // c 1 Error: Unexpected COMMON statement at (1) zlctc_1.f90:4.14: common // c 1 Error: Unexpected COMMON statement at (1) # ^C after a few minutes