C PATCH to improve location for abstract declarators (PR c/71362)

[Marek Polacek]

This fixes an imprecise location info with abstract declarators.  The problem
was that when we build_id_declarator, the default location was input_location
and we never attempted to use a more precise location.  This patch does it.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2016-06-03  Marek Polacek  <pola...@redhat.com>

        PR c/71362
        * c-parser.c (c_parser_direct_declarator): Set location.

        * gcc.dg/pr71362.c: New test.

diff --git gcc/c/c-parser.c gcc/c/c-parser.c
index bca8653..799a473 100644
--- gcc/c/c-parser.c
+++ gcc/c/c-parser.c
@@ -3430,6 +3430,7 @@ c_parser_direct_declarator (c_parser *parser, bool 
type_seen_p, c_dtr_syn kind,
       && c_parser_next_token_is (parser, CPP_OPEN_SQUARE))
     {
       struct c_declarator *inner = build_id_declarator (NULL_TREE);
+      inner->id_loc = c_parser_peek_token (parser)->location;
       return c_parser_direct_declarator_inner (parser, *seen_id, inner);
     }
 
diff --git gcc/testsuite/gcc.dg/pr71362.c gcc/testsuite/gcc.dg/pr71362.c
index e69de29..fd9cd6a 100644
--- gcc/testsuite/gcc.dg/pr71362.c
+++ gcc/testsuite/gcc.dg/pr71362.c
@@ -0,0 +1,10 @@
+/* PR c/71362 */
+/* { dg-do compile } */
+
+extern void foo (int[-1]); /* { dg-error "21:size of unnamed array is 
negative" } */
+
+int
+bar (void)
+{
+  123 + sizeof (int[-1]); /* { dg-error "20:size of unnamed array is negative" 
} */
+}

        Marek