[Bug lto/46796] New: debug info missing builtin type names on darwin

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46796

           Summary: debug info missing builtin type names on darwin
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mrs@gcc.gnu.org


int i;

doesn't preserve the name "int" on the type under lto.  Consider:

$ cat t.c
volatile float a1, a2;

void * volatile vp;

void f(int i) {
  a1 = i;
  a1 = a2;
}

int main() {
  f(12);
  return 0;
}

$ ./xgcc -B./ -flto t.c -g -v -Wl,-debug -save-temps
$ grep int cc*.s 
$ ./xgcc -B./ -S t.c -g -o t-normal.s
$ grep int t-normal.s 
    .ascii "int\0"

because of this, this code:


  /* This probably indicates a bug.  */
  else if (mod_type_die && mod_type_die->die_tag == DW_TAG_base_type)
    add_name_attribute (mod_type_die, "__unknown__");

in dwarf2out.c adds a name __unknown__ to most things, and under gdb, we get:

(gdb) start
(gdb) step
(gdb) ptype i
type = __unknown__

instead of:

(gdb) start
(gdb) step
(gdb) ptype i
type = int

when we compile without -flto.  If the name was preserved, then the type would
have the right name, instead of __unknown__.