[PATCH] Fix PR77863

[Richard Biener]

Applied as obvious.

Richard.

2016-10-05  Richard Biener  <rguent...@suse.de>

        PR middle-end/77863
        * genmatch.c (capture_info::walk_c_expr): Diagnose unknown
        capture ids in c-exprs.

Index: gcc/genmatch.c
===================================================================
--- gcc/genmatch.c      (revision 240776)
+++ gcc/genmatch.c      (working copy)
@@ -2194,8 +2194,10 @@ capture_info::walk_c_expr (c_expr *e)
            id = (const char *)n->val.str.text;
          else
            id = (const char *)CPP_HASHNODE (n->val.node.node)->ident.str;
-         unsigned where = *e->capture_ids->get(id);
-         info[info[where].same_as].force_no_side_effects_p = true;
+         unsigned *where = e->capture_ids->get(id);
+         if (! where)
+           fatal_at (n, "unknown capture id '%s'", id);
+         info[info[*where].same_as].force_no_side_effects_p = true;
          if (verbose >= 1
              && !gimple)
            warning_at (t, "capture escapes");