[Bug c/59957] New: ICE in read_line_num when re-#define-ing a -DVAR=...

["burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59957

            Bug ID: 59957
           Summary: ICE in read_line_num when re-#define-ing a -DVAR=...
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org

Running

  gcc -c -DNDEBUG=1 test.c

on the following code will give an ICE:

  #ifndef DEBUG
  #define NDEBUG  /* Re-define NDEBUG - should warn but not ICE  */
  #endif
  #include <assert.h>


will give an ICE with 4.9:


0xfa2248 read_line_num
        ../../gcc/input.c:603
0xfa2248 location_get_source_line(expanded_location, int*)
        ../../gcc/input.c:702
0xf9cf4b diagnostic_show_locus(diagnostic_context*, diagnostic_info const*)
        ../../gcc/diagnostic.c:304
0xf9df8b diagnostic_report_diagnostic(diagnostic_context*, diagnostic_info*)
        ../../gcc/diagnostic.c:800
0x635024 c_cpp_error(cpp_reader*, int, int, unsigned int, unsigned int, char
const*, __va_list_tag (*) [1])
        ../../gcc/c-family/c-common.c:9639
0xfac796 cpp_error_with_line(cpp_reader*, int, unsigned int, unsigned int, char
const*, ...)
        ../../libcpp/errors.c:163
0xfbc7ef _cpp_create_definition
        ../../libcpp/macro.c:3124