gcc/:

	* c.opt (Wenum-compare): Enable for C and Objc.  Initialize to -1.
	* c-opts.c (c_common_handle_option): For C, set warn_enum_compare
	for -Wall and for -Wc++-compat.
	(c_common_post_options): For C++, set warn_enum_compare if not
	already set.
	* c-tree.h (struct c_expr): Add field original_type.
	(build_external_ref): Update declaration.
	* c-parser.c (c_parser_braced_init): Set original_type.
	(c_parser_initelt): Likewise.
	(c_parser_expr_no_commas): Likewise.
	(c_parser_conditional_expression): Likewise.
	(c_parser_cast_expression): Likewise.
	(c_parser_unary_expression): Likewise.  Pull setting of
	original_code to top of function.
	(c_parser_sizeof_expression): Set original_type.
	(c_parser_alignof_expression): Likewise.
	(c_parser_postfix_expression): Likewise.  Pull setting of
	original_code to top of function.
	(c_parser_postfix_expression_after_paren_type): Set
	original_type.
	(c_parser_postfix_expression_after_primary): Likewise.
	(c_parser_expression): Likewise.
	* c-typeck.c (build_external_ref): Add type parameter.  Change all
	callers.
	(c_expr_sizeof_expr): Set original_type field.
	(parser_build_unary_op): Likewise.
	(parser_build_binary_op): Likewise.  Optionally warn about
	comparisons of enums of different types.
	(digest_init): Set original_type field.
	(really_start_incremental_init): Likewise.
	(push_init_level, pop_init_level): Likewise.
	* doc/invoke.texi (Warning Options): -Wenum-compare now
	supported in C.
gcc/testsuite/:
	* gcc.dg/Wenum-compare-1.c: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@146127 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6898c7c..eb0ccb1 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,39 @@
+2009-04-15  Ian Lance Taylor  <iant@google.com>
+
+       * c.opt (Wenum-compare): Enable for C and Objc.  Initialize to -1.
+       * c-opts.c (c_common_handle_option): For C, set warn_enum_compare
+       for -Wall and for -Wc++-compat.
+       (c_common_post_options): For C++, set warn_enum_compare if not
+       already set.
+       * c-tree.h (struct c_expr): Add field original_type.
+       (build_external_ref): Update declaration.
+       * c-parser.c (c_parser_braced_init): Set original_type.
+       (c_parser_initelt): Likewise.
+       (c_parser_expr_no_commas): Likewise.
+       (c_parser_conditional_expression): Likewise.
+       (c_parser_cast_expression): Likewise.
+       (c_parser_unary_expression): Likewise.  Pull setting of
+       original_code to top of function.
+       (c_parser_sizeof_expression): Set original_type.
+       (c_parser_alignof_expression): Likewise.
+       (c_parser_postfix_expression): Likewise.  Pull setting of
+       original_code to top of function.
+       (c_parser_postfix_expression_after_paren_type): Set
+       original_type.
+       (c_parser_postfix_expression_after_primary): Likewise.
+       (c_parser_expression): Likewise.
+       * c-typeck.c (build_external_ref): Add type parameter.  Change all
+       callers.
+       (c_expr_sizeof_expr): Set original_type field.
+       (parser_build_unary_op): Likewise.
+       (parser_build_binary_op): Likewise.  Optionally warn about
+       comparisons of enums of different types.
+       (digest_init): Set original_type field.
+       (really_start_incremental_init): Likewise.
+       (push_init_level, pop_init_level): Likewise.
+       * doc/invoke.texi (Warning Options): -Wenum-compare now
+       supported in C.
+
 2009-04-15  Richard Guenther  <rguenther@suse.de>
 
        * tree-ssa-pre.c (eliminate): When replacing a PHI node carry

diff --git a/gcc/c-opts.c b/gcc/c-opts.c
index 54edf30..f619522 100644 (file)
--- a/gcc/c-opts.c
+++ b/gcc/c-opts.c
@@ -412,6 +412,12 @@ c_common_handle_option (size_t scode, const char *arg, int value)
             can turn it off only if it's not explicit.  */
          if (warn_main == -1)
            warn_main = (value ? 2 : 0);
+
+         /* In C, -Wall turns on -Wenum-compare, which we do here.
+            In C++ it is on by default, which is done in
+            c_common_post_options.  */
+          if (warn_enum_compare == -1)
+            warn_enum_compare = value;
        }
       else
        {
@@ -438,6 +444,13 @@ c_common_handle_option (size_t scode, const char *arg, int value)
       cpp_opts->warn_comments = value;
       break;
 
+    case OPT_Wc___compat:
+      /* Because -Wenum-compare is the default in C++, -Wc++-compat
+        implies -Wenum-compare.  */
+      if (warn_enum_compare == -1 && value)
+       warn_enum_compare = value;
+      break;
+
     case OPT_Wdeprecated:
       cpp_opts->warn_deprecated = value;
       break;
@@ -1099,6 +1112,12 @@ c_common_post_options (const char **pfilename)
   if (warn_sign_conversion == -1)
     warn_sign_conversion =  (c_dialect_cxx ()) ? 0 : warn_conversion;
 
+  /* In C, -Wall and -Wc++-compat enable -Wenum-compare, which we do
+     in c_common_handle_option; if it has not yet been set, it is
+     disabled by default.  In C++, it is enabled by default.  */
+  if (warn_enum_compare == -1)
+    warn_enum_compare = c_dialect_cxx () ? 1 : 0;
+
   /* -Wpacked-bitfield-compat is on by default for the C languages.  The
      warning is issued in stor-layout.c which is not part of the front-end so
      we need to selectively turn it on here.  */

diff --git a/gcc/c-parser.c b/gcc/c-parser.c
index 7887391..9b3ace5 100644 (file)
--- a/gcc/c-parser.c
+++ b/gcc/c-parser.c
@@ -3044,6 +3044,7 @@ c_parser_braced_init (c_parser *parser, tree type, bool nested_p)
       struct c_expr ret;
       ret.value = error_mark_node;
       ret.original_code = ERROR_MARK;
+      ret.original_type = NULL;
       c_parser_skip_until_found (parser, CPP_CLOSE_BRACE, "expected %<}%>");
       pop_init_level (0);
       return ret;
@@ -3100,6 +3101,7 @@ c_parser_initelt (c_parser *parser)
                  struct c_expr init;
                  init.value = error_mark_node;
                  init.original_code = ERROR_MARK;
+                 init.original_type = NULL;
                  c_parser_error (parser, "expected identifier");
                  c_parser_skip_until_found (parser, CPP_COMMA, NULL);
                  process_init_element (init, false);
@@ -3174,6 +3176,7 @@ c_parser_initelt (c_parser *parser)
                  mexpr.value
                    = objc_build_message_expr (build_tree_list (rec, args));
                  mexpr.original_code = ERROR_MARK;
+                 mexpr.original_type = NULL;
                  /* Now parse and process the remainder of the
                     initializer, starting with this message
                     expression as a primary-expression.  */
@@ -3223,6 +3226,7 @@ c_parser_initelt (c_parser *parser)
                  struct c_expr init;
                  init.value = error_mark_node;
                  init.original_code = ERROR_MARK;
+                 init.original_type = NULL;
                  c_parser_error (parser, "expected %<=%>");
                  c_parser_skip_until_found (parser, CPP_COMMA, NULL);
                  process_init_element (init, false);
@@ -4438,6 +4442,7 @@ c_parser_expr_no_commas (c_parser *parser, struct c_expr *after)
       TREE_NO_WARNING (ret.value) = 1;
       ret.original_code = ERROR_MARK;
     }
+  ret.original_type = NULL;
   return ret;
 }
 
@@ -4485,6 +4490,7 @@ c_parser_conditional_expression (c_parser *parser, struct c_expr *after)
       exp1.value = c_save_expr (default_conversion (cond.value));
       if (eptype)
        exp1.value = build1 (EXCESS_PRECISION_EXPR, eptype, exp1.value);
+      exp1.original_type = NULL;
       cond.value = c_objc_common_truthvalue_conversion (cond_loc, exp1.value);
       skip_evaluation += cond.value == truthvalue_true_node;
     }
@@ -4503,6 +4509,7 @@ c_parser_conditional_expression (c_parser *parser, struct c_expr *after)
       skip_evaluation -= cond.value == truthvalue_true_node;
       ret.value = error_mark_node;
       ret.original_code = ERROR_MARK;
+      ret.original_type = NULL;
       return ret;
     }
   exp2 = c_parser_conditional_expression (parser, NULL);
@@ -4512,6 +4519,24 @@ c_parser_conditional_expression (c_parser *parser, struct c_expr *after)
                                      cond.original_code == C_MAYBE_CONST_EXPR,
                                      exp1.value, exp2.value);
   ret.original_code = ERROR_MARK;
+  if (exp1.value == error_mark_node || exp2.value == error_mark_node)
+    ret.original_type = NULL;
+  else
+    {
+      tree t1, t2;
+
+      /* If both sides are enum type, the default conversion will have
+        made the type of the result be an integer type.  We want to
+        remember the enum types we started with.  */
+      t1 = exp1.original_type ? exp1.original_type : TREE_TYPE (exp1.value);
+      t2 = exp2.original_type ? exp2.original_type : TREE_TYPE (exp2.value);
+      ret.original_type = ((t1 != error_mark_node
+                           && t2 != error_mark_node
+                           && (TYPE_MAIN_VARIANT (t1)
+                               == TYPE_MAIN_VARIANT (t2)))
+                          ? t1
+                          : NULL);
+    }
   return ret;
 }
 
@@ -4800,6 +4825,7 @@ c_parser_cast_expression (c_parser *parser, struct c_expr *after)
        {
          ret.value = error_mark_node;
          ret.original_code = ERROR_MARK;
+         ret.original_type = NULL;
          return ret;
        }
 
@@ -4813,6 +4839,7 @@ c_parser_cast_expression (c_parser *parser, struct c_expr *after)
       expr = default_function_array_conversion (expr);
       ret.value = c_cast_expr (type_name, expr.value);
       ret.original_code = ERROR_MARK;
+      ret.original_type = NULL;
       return ret;
     }
   else
@@ -4852,6 +4879,8 @@ c_parser_unary_expression (c_parser *parser)
   int ext;
   struct c_expr ret, op;
   location_t loc = c_parser_peek_token (parser)->location;
+  ret.original_code = ERROR_MARK;
+  ret.original_type = NULL;
   switch (c_parser_peek_token (parser)->type)
     {
     case CPP_PLUS_PLUS:
@@ -4874,7 +4903,6 @@ c_parser_unary_expression (c_parser *parser)
       op = c_parser_cast_expression (parser, NULL);
       op = default_function_array_conversion (op);
       ret.value = build_indirect_ref (loc, op.value, "unary *");
-      ret.original_code = ERROR_MARK;
       return ret;
     case CPP_PLUS:
       if (!c_dialect_objc () && !in_system_header)
@@ -4914,7 +4942,6 @@ c_parser_unary_expression (c_parser *parser)
          c_parser_error (parser, "expected identifier");
          ret.value = error_mark_node;
        }
-       ret.original_code = ERROR_MARK;
        return ret;
     case CPP_KEYWORD:
       switch (c_parser_peek_token (parser)->keyword)
@@ -4975,6 +5002,7 @@ c_parser_sizeof_expression (c_parser *parser)
          in_sizeof--;
          ret.value = error_mark_node;
          ret.original_code = ERROR_MARK;
+         ret.original_type = NULL;
          return ret;
        }
       if (c_parser_next_token_is (parser, CPP_OPEN_BRACE))
@@ -5029,6 +5057,7 @@ c_parser_alignof_expression (c_parser *parser)
          in_alignof--;
          ret.value = error_mark_node;
          ret.original_code = ERROR_MARK;
+         ret.original_type = NULL;
          return ret;
        }
       if (c_parser_next_token_is (parser, CPP_OPEN_BRACE))
@@ -5042,6 +5071,7 @@ c_parser_alignof_expression (c_parser *parser)
       in_alignof--;
       ret.value = c_alignof (groktypename (type_name, NULL, NULL));
       ret.original_code = ERROR_MARK;
+      ret.original_type = NULL;
       return ret;
     }
   else
@@ -5053,6 +5083,7 @@ c_parser_alignof_expression (c_parser *parser)
       in_alignof--;
       ret.value = c_alignof_expr (expr.value);
       ret.original_code = ERROR_MARK;
+      ret.original_type = NULL;
       return ret;
     }
 }
@@ -5116,11 +5147,12 @@ c_parser_postfix_expression (c_parser *parser)
   struct c_expr expr, e1, e2, e3;
   struct c_type_name *t1, *t2;
   location_t loc;
+  expr.original_code = ERROR_MARK;
+  expr.original_type = NULL;
   switch (c_parser_peek_token (parser)->type)
     {
     case CPP_NUMBER:
       expr.value = c_parser_peek_token (parser)->value;
-      expr.original_code = ERROR_MARK;
       loc = c_parser_peek_token (parser)->location;
       c_parser_consume_token (parser);
       if (TREE_CODE (expr.value) == FIXED_CST
@@ -5135,7 +5167,6 @@ c_parser_postfix_expression (c_parser *parser)
     case CPP_CHAR32:
     case CPP_WCHAR:
       expr.value = c_parser_peek_token (parser)->value;
-      expr.original_code = ERROR_MARK;
       c_parser_consume_token (parser);
       break;
     case CPP_STRING:
@@ -5150,7 +5181,6 @@ c_parser_postfix_expression (c_parser *parser)
       gcc_assert (c_dialect_objc ());
       expr.value
        = objc_build_string_object (c_parser_peek_token (parser)->value);
-      expr.original_code = ERROR_MARK;
       c_parser_consume_token (parser);
       break;
     case CPP_NAME:
@@ -5158,7 +5188,6 @@ c_parser_postfix_expression (c_parser *parser)
        {
          c_parser_error (parser, "expected expression");
          expr.value = error_mark_node;
-         expr.original_code = ERROR_MARK;
          break;
        }
       {
@@ -5167,8 +5196,8 @@ c_parser_postfix_expression (c_parser *parser)
        c_parser_consume_token (parser);
        expr.value = build_external_ref (id,
                                         (c_parser_peek_token (parser)->type
-                                         == CPP_OPEN_PAREN), loc);
-       expr.original_code = ERROR_MARK;
+                                         == CPP_OPEN_PAREN), loc,
+                                        &expr.original_type);
       }
       break;
     case CPP_OPEN_PAREN:
@@ -5189,7 +5218,6 @@ c_parser_postfix_expression (c_parser *parser)
              c_parser_skip_until_found (parser, CPP_CLOSE_BRACE, NULL);
              c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          stmt = c_begin_stmt_expr ();
@@ -5199,7 +5227,6 @@ c_parser_postfix_expression (c_parser *parser)
          pedwarn (here, OPT_pedantic, 
                   "ISO C forbids braced-groups within expressions");
          expr.value = c_finish_stmt_expr (stmt);
-         expr.original_code = ERROR_MARK;
        }
       else if (c_token_starts_typename (c_parser_peek_2nd_token (parser)))
        {
@@ -5215,7 +5242,6 @@ c_parser_postfix_expression (c_parser *parser)
          if (type_name == NULL)
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
            }
          else
            expr = c_parser_postfix_expression_after_paren_type (parser,
@@ -5230,6 +5256,7 @@ c_parser_postfix_expression (c_parser *parser)
            TREE_NO_WARNING (expr.value) = 1;
          if (expr.original_code != C_MAYBE_CONST_EXPR)
            expr.original_code = ERROR_MARK;
+         /* Don't change EXPR.ORIGINAL_TYPE.  */
          c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
                                     "expected %<)%>");
        }
@@ -5243,7 +5270,6 @@ c_parser_postfix_expression (c_parser *parser)
          expr.value = fname_decl (c_parser_peek_token (parser)->location,
                                   c_parser_peek_token (parser)->keyword,
                                   c_parser_peek_token (parser)->value);
-         expr.original_code = ERROR_MARK;
          c_parser_consume_token (parser);
          break;
        case RID_VA_ARG:
@@ -5251,7 +5277,6 @@ c_parser_postfix_expression (c_parser *parser)
          if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          e1 = c_parser_expr_no_commas (parser, NULL);
@@ -5260,7 +5285,6 @@ c_parser_postfix_expression (c_parser *parser)
            {
              c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          t1 = c_parser_type_name (parser);
@@ -5269,7 +5293,6 @@ c_parser_postfix_expression (c_parser *parser)
          if (t1 == NULL)
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
            }
          else
            {
@@ -5284,7 +5307,6 @@ c_parser_postfix_expression (c_parser *parser)
                                       expr.value);
                  C_MAYBE_CONST_EXPR_NON_CONST (expr.value) = true;
                }
-             expr.original_code = ERROR_MARK;
            }
          break;
        case RID_OFFSETOF:
@@ -5292,21 +5314,18 @@ c_parser_postfix_expression (c_parser *parser)
          if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          t1 = c_parser_type_name (parser);
          if (t1 == NULL)
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          if (!c_parser_require (parser, CPP_COMMA, "expected %<,%>"))
            {
              c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          {
@@ -5371,7 +5390,6 @@ c_parser_postfix_expression (c_parser *parser)
            c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
                                       "expected %<)%>");
            expr.value = fold_offsetof (offsetof_ref, NULL_TREE);
-           expr.original_code = ERROR_MARK;
          }
          break;
        case RID_CHOOSE_EXPR:
@@ -5379,7 +5397,6 @@ c_parser_postfix_expression (c_parser *parser)
          if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          loc = c_parser_peek_token (parser)->location;
@@ -5388,7 +5405,6 @@ c_parser_postfix_expression (c_parser *parser)
            {
              c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          e2 = c_parser_expr_no_commas (parser, NULL);
@@ -5396,7 +5412,6 @@ c_parser_postfix_expression (c_parser *parser)
            {
              c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          e3 = c_parser_expr_no_commas (parser, NULL);
@@ -5420,28 +5435,24 @@ c_parser_postfix_expression (c_parser *parser)
          if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          t1 = c_parser_type_name (parser);
          if (t1 == NULL)
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          if (!c_parser_require (parser, CPP_COMMA, "expected %<,%>"))
            {
              c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          t2 = c_parser_type_name (parser);
          if (t2 == NULL)
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
@@ -5455,7 +5466,6 @@ c_parser_postfix_expression (c_parser *parser)
            expr.value = comptypes (e1, e2)
              ? build_int_cst (NULL_TREE, 1)
              : build_int_cst (NULL_TREE, 0);
-           expr.original_code = ERROR_MARK;
          }
          break;
        case RID_AT_SELECTOR:
@@ -5464,7 +5474,6 @@ c_parser_postfix_expression (c_parser *parser)
          if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          {
@@ -5472,7 +5481,6 @@ c_parser_postfix_expression (c_parser *parser)
            c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
                                       "expected %<)%>");
            expr.value = objc_build_selector_expr (sel);
-           expr.original_code = ERROR_MARK;
          }
          break;
        case RID_AT_PROTOCOL:
@@ -5481,7 +5489,6 @@ c_parser_postfix_expression (c_parser *parser)
          if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          if (c_parser_next_token_is_not (parser, CPP_NAME))
@@ -5489,7 +5496,6 @@ c_parser_postfix_expression (c_parser *parser)
              c_parser_error (parser, "expected identifier");
              c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          {
@@ -5498,7 +5504,6 @@ c_parser_postfix_expression (c_parser *parser)
            c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
                                       "expected %<)%>");
            expr.value = objc_build_protocol_expr (id);
-           expr.original_code = ERROR_MARK;
          }
          break;
        case RID_AT_ENCODE:
@@ -5508,14 +5513,12 @@ c_parser_postfix_expression (c_parser *parser)
          if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              break;
            }
          t1 = c_parser_type_name (parser);
          if (t1 == NULL)
            {
              expr.value = error_mark_node;
-             expr.original_code = ERROR_MARK;
              c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, NULL);
              break;
            }
@@ -5524,13 +5527,11 @@ c_parser_postfix_expression (c_parser *parser)
          {
            tree type = groktypename (t1, NULL, NULL);
            expr.value = objc_build_encode_expr (type);
-           expr.original_code = ERROR_MARK;
          }
          break;
        default:
          c_parser_error (parser, "expected expression");
          expr.value = error_mark_node;
-         expr.original_code = ERROR_MARK;
          break;
        }
       break;
@@ -5545,14 +5546,12 @@ c_parser_postfix_expression (c_parser *parser)
                                     "expected %<]%>");
          expr.value = objc_build_message_expr (build_tree_list (receiver,
                                                                 args));
-         expr.original_code = ERROR_MARK;
          break;
        }
       /* Else fall through to report error.  */
     default:
       c_parser_error (parser, "expected expression");
       expr.value = error_mark_node;
-      expr.original_code = ERROR_MARK;
       break;
     }
   return c_parser_postfix_expression_after_primary (parser, expr);
@@ -5597,6 +5596,7 @@ c_parser_postfix_expression_after_paren_type (c_parser *parser,
   non_const |= !type_expr_const;
   expr.value = build_compound_literal (type, init.value, non_const);
   expr.original_code = ERROR_MARK;
+  expr.original_type = NULL;
   if (type_expr)
     {
       if (TREE_CODE (expr.value) == C_MAYBE_CONST_EXPR)
@@ -5637,6 +5637,7 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
                                     "expected %<]%>");
          expr.value = build_array_ref (expr.value, idx, loc);
          expr.original_code = ERROR_MARK;
+         expr.original_type = NULL;
          break;
        case CPP_OPEN_PAREN:
          /* Function call.  */
@@ -5655,6 +5656,7 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
              && DECL_BUILT_IN_CLASS (orig_expr.value) == BUILT_IN_NORMAL
              && DECL_FUNCTION_CODE (orig_expr.value) == BUILT_IN_CONSTANT_P)
            expr.original_code = C_MAYBE_CONST_EXPR;
+         expr.original_type = NULL;
          break;
        case CPP_DOT:
          /* Structure element reference.  */
@@ -5667,11 +5669,23 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
              c_parser_error (parser, "expected identifier");
              expr.value = error_mark_node;
              expr.original_code = ERROR_MARK;
+              expr.original_type = NULL;
              return expr;
            }
          c_parser_consume_token (parser);
          expr.value = build_component_ref (expr.value, ident);
          expr.original_code = ERROR_MARK;
+         if (TREE_CODE (expr.value) != COMPONENT_REF)
+           expr.original_type = NULL;
+         else
+           {
+             /* Remember the original type of a bitfield.  */
+             tree field = TREE_OPERAND (expr.value, 1);
+             if (TREE_CODE (field) != FIELD_DECL)
+               expr.original_type = NULL;
+             else
+               expr.original_type = DECL_BIT_FIELD_TYPE (field);
+           }
          break;
        case CPP_DEREF:
          /* Structure element reference.  */
@@ -5684,6 +5698,7 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
              c_parser_error (parser, "expected identifier");
              expr.value = error_mark_node;
              expr.original_code = ERROR_MARK;
+             expr.original_type = NULL;
              return expr;
            }
          c_parser_consume_token (parser);
@@ -5692,6 +5707,17 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
                                                                "->"),
                                            ident);
          expr.original_code = ERROR_MARK;
+         if (TREE_CODE (expr.value) != COMPONENT_REF)
+           expr.original_type = NULL;
+         else
+           {
+             /* Remember the original type of a bitfield.  */
+             tree field = TREE_OPERAND (expr.value, 1);
+             if (TREE_CODE (field) != FIELD_DECL)
+               expr.original_type = NULL;
+             else
+               expr.original_type = DECL_BIT_FIELD_TYPE (field);
+           }
          break;
        case CPP_PLUS_PLUS:
          /* Postincrement.  */
@@ -5700,6 +5726,7 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
          expr.value = build_unary_op (loc,
                                       POSTINCREMENT_EXPR, expr.value, 0);
          expr.original_code = ERROR_MARK;
+         expr.original_type = NULL;
          break;
        case CPP_MINUS_MINUS:
          /* Postdecrement.  */
@@ -5708,6 +5735,7 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
          expr.value = build_unary_op (loc,
                                       POSTDECREMENT_EXPR, expr.value, 0);
          expr.original_code = ERROR_MARK;
+         expr.original_type = NULL;
          break;
        default:
          return expr;
@@ -5735,6 +5763,7 @@ c_parser_expression (c_parser *parser)
       next = default_function_array_conversion (next);
       expr.value = build_compound_expr (expr.value, next.value);
       expr.original_code = COMPOUND_EXPR;
+      expr.original_type = NULL;
     }
   return expr;
 }

diff --git a/gcc/c-tree.h b/gcc/c-tree.h
index ac9586b..6b9fcc7 100644 (file)
--- a/gcc/c-tree.h
+++ b/gcc/c-tree.h
@@ -163,6 +163,11 @@ struct c_expr
      initializers, or ERROR_MARK for other expressions (including
      parenthesized expressions).  */
   enum tree_code original_code;
+  /* If not NULL, the original type of an expression.  This will
+     differ from the type of the value field for an enum constant.
+     The type of an enum constant is a plain integer type, but this
+     field will be the enum type.  */
+  tree original_type;
 };
 
 /* A kind of type specifier.  Note that this information is currently
@@ -577,7 +582,7 @@ extern struct c_expr default_function_array_conversion (struct c_expr);
 extern tree composite_type (tree, tree);
 extern tree build_component_ref (tree, tree);
 extern tree build_array_ref (tree, tree, location_t);
-extern tree build_external_ref (tree, int, location_t);
+extern tree build_external_ref (tree, int, location_t, tree *);
 extern void pop_maybe_used (bool);
 extern struct c_expr c_expr_sizeof_expr (struct c_expr);
 extern struct c_expr c_expr_sizeof_type (struct c_type_name *);

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index 9c74bf3..c6bb9f8 100644 (file)
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -2202,9 +2202,12 @@ build_array_ref (tree array, tree index, location_t loc)
 \f
 /* Build an external reference to identifier ID.  FUN indicates
    whether this will be used for a function call.  LOC is the source
-   location of the identifier.  */
+   location of the identifier.  This sets *TYPE to the type of the
+   identifier, which is not the same as the type of the returned value
+   for CONST_DECLs defined as enum constants.  If the type of the
+   identifier is not available, *TYPE is set to NULL.  */
 tree
-build_external_ref (tree id, int fun, location_t loc)
+build_external_ref (tree id, int fun, location_t loc, tree *type)
 {
   tree ref;
   tree decl = lookup_name (id);
@@ -2213,8 +2216,12 @@ build_external_ref (tree id, int fun, location_t loc)
      whatever lookup_name() found.  */
   decl = objc_lookup_ivar (decl, id);
 
+  *type = NULL;
   if (decl && decl != error_mark_node)
-    ref = decl;
+    {
+      ref = decl;
+      *type = TREE_TYPE (ref);
+    }
   else if (fun)
     /* Implicit function declaration.  */
     ref = implicitly_declare (id);
@@ -2346,6 +2353,7 @@ c_expr_sizeof_expr (struct c_expr expr)
     {
       ret.value = error_mark_node;
       ret.original_code = ERROR_MARK;
+      ret.original_type = NULL;
       pop_maybe_used (false);
     }
   else
@@ -2355,6 +2363,7 @@ c_expr_sizeof_expr (struct c_expr expr)
                                       &expr_const_operands);
       ret.value = c_sizeof (TREE_TYPE (folded_expr));
       ret.original_code = ERROR_MARK;
+      ret.original_type = NULL;
       if (c_vla_type_p (TREE_TYPE (folded_expr)))
        {
          /* sizeof is evaluated when given a vla (C99 6.5.3.4p2).  */
@@ -2380,6 +2389,7 @@ c_expr_sizeof_type (struct c_type_name *t)
   type = groktypename (t, &type_expr, &type_expr_const);
   ret.value = c_sizeof (type);
   ret.original_code = ERROR_MARK;
+  ret.original_type = NULL;
   if (type_expr && c_vla_type_p (type))
     {
       ret.value = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (ret.value),
@@ -2856,7 +2866,8 @@ parser_build_unary_op (enum tree_code code, struct c_expr arg, location_t loc)
 
   result.value = build_unary_op (loc, code, arg.value, 0);
   result.original_code = code;
-  
+  result.original_type = NULL;
+
   if (TREE_OVERFLOW_P (result.value) && !TREE_OVERFLOW_P (arg.value))
     overflow_warning (result.value);
 
@@ -2879,10 +2890,17 @@ parser_build_binary_op (location_t location, enum tree_code code,
 
   enum tree_code code1 = arg1.original_code;
   enum tree_code code2 = arg2.original_code;
+  tree type1 = (arg1.original_type
+                ? arg1.original_type
+                : TREE_TYPE (arg1.value));
+  tree type2 = (arg2.original_type
+                ? arg2.original_type
+                : TREE_TYPE (arg2.value));
 
   result.value = build_binary_op (location, code,
                                  arg1.value, arg2.value, 1);
   result.original_code = code;
+  result.original_type = NULL;
 
   if (TREE_CODE (result.value) == ERROR_MARK)
     return result;
@@ -2915,6 +2933,16 @@ parser_build_binary_op (location_t location, enum tree_code code,
       && !TREE_OVERFLOW_P (arg2.value))
     overflow_warning (result.value);
 
+  /* Warn about comparisons of different enum types.  */
+  if (warn_enum_compare
+      && TREE_CODE_CLASS (code) == tcc_comparison
+      && TREE_CODE (type1) == ENUMERAL_TYPE
+      && TREE_CODE (type2) == ENUMERAL_TYPE
+      && TYPE_MAIN_VARIANT (type1) != TYPE_MAIN_VARIANT (type2))
+    warning_at (location, OPT_Wenum_compare,
+               "comparison between %qT and %qT",
+               type1, type2);
+
   return result;
 }
 \f
@@ -5171,6 +5199,7 @@ digest_init (tree type, tree init, bool null_pointer_constant,
          tree typ2 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)));
          expr.value = inside_init;
          expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
+         expr.original_type = NULL;
          maybe_warn_string_init (type, expr);
 
          if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
@@ -5690,6 +5719,7 @@ really_start_incremental_init (tree type)
   p->depth = constructor_depth;
   p->replacement_value.value = 0;
   p->replacement_value.original_code = ERROR_MARK;
+  p->replacement_value.original_type = NULL;
   p->implicit = 0;
   p->range_stack = 0;
   p->outer = 0;
@@ -5833,6 +5863,7 @@ push_init_level (int implicit)
   p->depth = constructor_depth;
   p->replacement_value.value = 0;
   p->replacement_value.original_code = ERROR_MARK;
+  p->replacement_value.original_type = NULL;
   p->implicit = implicit;
   p->outer = 0;
   p->incremental = constructor_incremental;
@@ -5989,6 +6020,7 @@ pop_init_level (int implicit)
   struct c_expr ret;
   ret.value = 0;
   ret.original_code = ERROR_MARK;
+  ret.original_type = NULL;
 
   if (implicit == 0)
     {

diff --git a/gcc/c.opt b/gcc/c.opt
index 3f1cd13..2a1b740 100644 (file)
--- a/gcc/c.opt
+++ b/gcc/c.opt
@@ -204,7 +204,7 @@ C ObjC C++ ObjC++ Warning
 Warn about stray tokens after #elif and #endif
 
 Wenum-compare
-C++ ObjC++ Var(warn_enum_compare) Init(1) Warning
+C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning
 Warn about comparison of different enum types
 
 Werror

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 554b6d9..12262f2 100644 (file)
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -2758,6 +2758,7 @@ Options} and @ref{Objective-C and Objective-C++ Dialect Options}.
 -Warray-bounds @r{(only with} @option{-O2}@r{)}  @gol
 -Wc++0x-compat  @gol
 -Wchar-subscripts  @gol
+-Wenum-compare @r{(in C/Objc; this is on by default in C++)} @gol
 -Wimplicit-int  @gol
 -Wimplicit-function-declaration  @gol
 -Wcomment  @gol
@@ -3743,11 +3744,12 @@ integers are disabled by default in C++ unless
 Warn if an empty body occurs in an @samp{if}, @samp{else} or @samp{do
 while} statement.  This warning is also enabled by @option{-Wextra}.
 
-@item -Wenum-compare @r{(C++ and Objective-C++ only)}
+@item -Wenum-compare
 @opindex Wenum-compare
 @opindex Wno-enum-compare
-Warn about a comparison between values of different enum types. This
-warning is enabled by default.
+Warn about a comparison between values of different enum types. In C++
+this warning is enabled by default.  In C this warning is enabled by
+@option{-Wall}.
 
 @item -Wsign-compare
 @opindex Wsign-compare

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f1a02b0..ffcd888 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-04-15  Ian Lance Taylor  <iant@google.com>
+
+       * gcc.dg/Wenum-compare-1.c: New testcase.
+
 2009-04-15  Richard Guenther  <rguenther@suse.de>
 
        PR tree-optimization/39764

diff --git a/gcc/testsuite/gcc.dg/Wenum-compare-1.c b/gcc/testsuite/gcc.dg/Wenum-compare-1.c
new file mode 100644 (file)
index 0000000..dd321e0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wenum-compare-1.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-Wenum-compare" } */
+enum E1 { A, B, C };
+enum E2 { D, E, F };
+extern void f2 ();
+void
+f1 ()
+{
+  int a = A;
+  int d = D;
+  enum E1 e1 = A;
+  enum E2 e2 = D;
+  if (A > D)   /* { dg-warning "comparison between .enum E1. and .enum E2." } */
+    f2 ();
+  if (e1 > e2)  /* { dg-warning "comparison between .enum E1. and .enum E2." } */
+    f2 ();
+  if (e1 > e2 + 1)
+    f2 ();
+  if (A > 0)
+    f2 ();
+  if (e1 > 0)
+    f2 ();
+  if (A + D > 0)
+    f2 ();
+  if (e1 > 0)
+    f2 ();
+  if (A + D > 0)
+    f2 ();
+  if ((int) A > D)
+    f2 ();
+  if ((int) e1 > e2)
+    f2 ();
+}