[Bug debug/55608] New: [4.6/4.7/4.8 Regression] Debug info quality regressions with file scope vars

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55608



             Bug #: 55608

           Summary: [4.6/4.7/4.8 Regression] Debug info quality

                    regressions with file scope vars

    Classification: Unclassified

           Product: gcc

           Version: 4.8.0

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: debug

        AssignedTo: ja...@gcc.gnu.org

        ReportedBy: ja...@gcc.gnu.org





static const char *a = "opq";

static const char b[8] = "rstuv";



int

main ()

{

  const char *p = "abcd";

  const char *q = "efgh";

  const char r[] = "ijk\0lmn";

  const char *s = r;

  return 0;

}



at -g -O2, gdb ./test; b main; p a; p b

shows

(gdb) p a

$1 = 0x400560 "opq"

(gdb) p b

$2 = "rstuv\000\000"

in e.g. GCC 3.2 or 3.3, but later on it is <optimized out>.  This is related to

PR55395, without reverting or adjusting part of that all the info is gone.

I have a patch which so far makes p b work (if a non-DECL_EXTERNAL variable is

optimized away and had an initializer, it means nothing is actually changing it

and so we can add DW_AT_const_value attribute), plans how to do some other vars

in this testcase.