[Bug middle-end/51010] New: [4.7 Regression] bad diagnostics: #'ssa_name' not supported by pp_c_expression#]'

[belyshev at depni dot sinp.msu.ru]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51010

             Bug #: 51010
           Summary: [4.7 Regression] bad diagnostics: #'ssa_name' not
                    supported by pp_c_expression#]'
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: minor
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: belyshev@depni.sinp.msu.ru
                CC: rguenth@gcc.gnu.org


Compiling this with -O1 -Wall will cause weird output:

int f (int j)
{
  int a [10];
  return a [j];
}

$ ./cc1 -quiet -O1 -Wall bug.c
#'ssa_name' not supported by pp_c_expression#]'bug.c: In function 'f':
bug.c:4:3: warning:  is used uninitialized in this function [-Wuninitialized]
$

Caused by r154918 (but was latent until the fix for pr50040, r177667):

    2009-12-02  Richard Guenther  <rguenther@suse.de>

        PR middle-end/42088
        * tree.c (free_lang_data): Disable if not using LTO.


Reverting r154918 helps:

bug.c: In function 'f':
bug.c:4:3: warning: 'a[j_1(D)]' is used uninitialized in this function
[-Wuninitialized]