[C PATCH] Better diagnostic for empty enum (PR c/67432)

[Marek Polacek]

This PR asks for a better error wrt empty enums.  So I've handled
empty enum specially.

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

2015-09-02  Marek Polacek  <pola...@redhat.com>

        PR c/67432
        * c-parser.c (c_parser_enum_specifier): Give a better error for
        an empty enum.

        * gcc.dg/pr67432.c: New test.

diff --git gcc/c/c-parser.c gcc/c/c-parser.c
index 1a58798..11a2b0f 100644
--- gcc/c/c-parser.c
+++ gcc/c/c-parser.c
@@ -2555,7 +2555,16 @@ c_parser_enum_specifier (c_parser *parser)
          location_t decl_loc, value_loc;
          if (c_parser_next_token_is_not (parser, CPP_NAME))
            {
-             c_parser_error (parser, "expected identifier");
+             /* Give a nicer error for "enum {}".  */
+             if (c_parser_next_token_is (parser, CPP_CLOSE_BRACE)
+                 && !parser->error)
+               {
+                 error_at (c_parser_peek_token (parser)->location,
+                           "empty enum is invalid");
+                 parser->error = true;
+               }
+             else
+               c_parser_error (parser, "expected identifier");
              c_parser_skip_until_found (parser, CPP_CLOSE_BRACE, NULL);
              values = error_mark_node;
              break;
diff --git gcc/testsuite/gcc.dg/pr67432.c gcc/testsuite/gcc.dg/pr67432.c
index e69de29..74367a9 100644
--- gcc/testsuite/gcc.dg/pr67432.c
+++ gcc/testsuite/gcc.dg/pr67432.c
@@ -0,0 +1,6 @@
+/* PR c/67432 */
+/* { dg-do compile } */
+
+enum {}; /* { dg-error "empty enum is invalid" } */
+enum E {}; /* { dg-error "empty enum is invalid" } */
+enum F {} e; /* { dg-error "empty enum is invalid" } */

        Marek