c-common.h (empty_body_warning): Rename to empty_if_body_warning.

2007-03-14  Dirk Mueller  <dmueller@suse.de>

        * c-common.h (empty_body_warning): Rename to empty_if_body_warning.
        * c-common.c (empty_if_body_warning): Rephrase diagnostic message.
        * c-parser.c (c_parser_if_body): Always add an empty statement in case
        of empty body.
        * c-parser.c (c_parser_do_statement): Warn about empty body in
        do/while statement.
        * c-typeck (c_finish_if_stmt): Call empty_if_body_warning.
        * doc/invoke.texi (-Wempty-body): Update documentation.

        * cp/semantics.c (c_finish_if_stmt): Call empty_if_body_warning.
        (finish_do_body): Warn about empty body in do/while statement.

        * g++.dg/warn/do-empty.C: New.
        * gcc.dg/do-empty.c: New.
        * gcc.dg/if-empty-1.c: Update.
        * gcc.dg/20001116-1.c: Update.
        * gcc.dg/pr23165.c: Update.

From-SVN: r122928

gcc/ChangeLog

@@ -1,3 +1,14 @@
+2007-03-14  Dirk Mueller  <dmueller@suse.de>
+
+	* c-common.h (empty_body_warning): Rename to empty_if_body_warning.
+	* c-common.c (empty_if_body_warning): Rephrase diagnostic message.
+	* c-parser.c (c_parser_if_body): Always add an empty statement in case
+	of empty body.
+	* c-parser.c (c_parser_do_statement): Warn about empty body in
+	do/while statement.
+	* c-typeck (c_finish_if_stmt): Call empty_if_body_warning.
+	* doc/invoke.texi (-Wempty-body): Update documentation.
+
 2007-03-14  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
 
 	PR c/21438

gcc/c-common.c

@@ -1056,9 +1056,7 @@ strict_aliasing_warning (tree otype, tree type, tree expr)
    block.  */
 
 void
-empty_body_warning (tree inner_then, tree inner_else)
+empty_if_body_warning (tree inner_then, tree inner_else)
-{
-  if (warn_empty_body)
 {
   if (TREE_CODE (inner_then) == STATEMENT_LIST
       && STATEMENT_LIST_TAIL (inner_then))
@@ -1069,13 +1067,12 @@ empty_body_warning (tree inner_then, tree inner_else)
     inner_else = STATEMENT_LIST_TAIL (inner_else)->stmt;
 
   if (IS_EMPTY_STMT (inner_then) && !inner_else)
-	warning (OPT_Wempty_body, "%Hempty body in an if-statement",
+    warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
-		 EXPR_LOCUS (inner_then));
+             "in an %<if%> statement", EXPR_LOCUS (inner_then));
 
-      if (inner_else && IS_EMPTY_STMT (inner_else))
+  else if (inner_else && IS_EMPTY_STMT (inner_else))
-	warning (OPT_Wempty_body, "%Hempty body in an else-statement",
+    warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
-		 EXPR_LOCUS (inner_else));
+             "in an %<else%> statement", EXPR_LOCUS (inner_else));
-   }
 }
 
 /* Warn for unlikely, improbable, or stupid DECL declarations

gcc/c-common.h

@@ -670,7 +670,7 @@ extern tree fix_string_type (tree);
 struct varray_head_tag;
 extern void constant_expression_warning (tree);
 extern void strict_aliasing_warning (tree, tree, tree);
-extern void empty_body_warning (tree, tree);
+extern void empty_if_body_warning (tree, tree);
 extern tree convert_and_check (tree, tree);
 extern void overflow_warning (tree);
 extern void warn_logical_operator (enum tree_code, tree, tree);

gcc/c-parser.c

@@ -3844,7 +3844,7 @@ c_parser_if_body (c_parser *parser, bool *if_p)
 	     && c_parser_peek_2nd_token (parser)->type == CPP_COLON))
     c_parser_label (parser);
   *if_p = c_parser_next_token_is_keyword (parser, RID_IF);
-  if (warn_empty_body && c_parser_next_token_is (parser, CPP_SEMICOLON))
+  if (c_parser_next_token_is (parser, CPP_SEMICOLON))
     add_stmt (build_empty_stmt ());
   c_parser_statement_after_labels (parser);
   return c_end_compound_stmt (block, flag_isoc99);
@@ -3953,6 +3953,9 @@ c_parser_do_statement (c_parser *parser)
   location_t loc;
   gcc_assert (c_parser_next_token_is_keyword (parser, RID_DO));
   c_parser_consume_token (parser);
+  if (c_parser_next_token_is (parser, CPP_SEMICOLON))
+    warning (OPT_Wempty_body,
+             "suggest braces around empty body in %<do%> statement");
   block = c_begin_compound_stmt (flag_isoc99);
   loc = c_parser_peek_token (parser)->location;
   save_break = c_break_label;

gcc/c-typeck.c

@@ -7229,7 +7229,7 @@ c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
 		  &if_locus);
     }
 
-  empty_body_warning (then_block, else_block);
+  empty_if_body_warning (then_block, else_block);
 
   stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
   SET_EXPR_LOCATION (stmt, if_locus);

gcc/cp/ChangeLog

@@ -1,3 +1,8 @@
+2007-03-14  Dirk Mueller  <dmueller@suse.de>
+
+	* cp/semantics.c (c_finish_if_stmt): Call empty_if_body_warning.
+	(finish_do_body): Warn about empty body in do/while statement.
+
 2007-03-14  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
 
 	* class.c (warn_hidden): Add OPT_Woverloaded_virtual to warning.

gcc/cp/semantics.c

@@ -701,7 +701,7 @@ finish_if_stmt (tree if_stmt)
   TREE_CHAIN (if_stmt) = NULL;
   add_stmt (do_poplevel (scope));
   finish_stmt ();
-  empty_body_warning (THEN_CLAUSE (if_stmt), ELSE_CLAUSE (if_stmt));
+  empty_if_body_warning (THEN_CLAUSE (if_stmt), ELSE_CLAUSE (if_stmt));
 }
 
 /* Begin a while-statement.  Returns a newly created WHILE_STMT if
@@ -754,7 +754,14 @@ begin_do_stmt (void)
 void
 finish_do_body (tree do_stmt)
 {
-  DO_BODY (do_stmt) = pop_stmt_list (DO_BODY (do_stmt));
+  tree body = DO_BODY (do_stmt) = pop_stmt_list (DO_BODY (do_stmt));
+
+  if (TREE_CODE (body) == STATEMENT_LIST && STATEMENT_LIST_TAIL (body))
+    body = STATEMENT_LIST_TAIL (body)->stmt;
+
+  if (IS_EMPTY_STMT (body))
+    warning (OPT_Wempty_body,
+            "suggest explicit braces around empty body in %<do%> statement");
 }
 
 /* Finish a do-statement, which may be given by DO_STMT, and whose

gcc/doc/invoke.texi

@@ -3136,8 +3136,9 @@ functions.  This warning can be independently controlled by
 @option{-Wmissing-parameter-type}.
 
 @item
-An empty body occurs in an @samp{if} or @samp{else} statement. This
+An empty body occurs in an @samp{if}, @samp{else} or
-warning can be independently controlled by @option{-Wempty-body}.
+@samp{do while} statement. This warning can be independently
+controlled by @option{-Wempty-body}.
 
 @item
 A pointer is compared against integer zero with @samp{<}, @samp{<=},
@@ -3397,8 +3398,8 @@ changed by the conversion like in @code{abs (2.0)}.
 
 @item -Wempty-body
 @opindex Wempty-body
-An empty body occurs in an @samp{if} or @samp{else} statement. 
+An empty body occurs in an @samp{if}, @samp{else} or @samp{do while}
-This warning is also enabled by @option{-Wextra}.
+statement.  This warning is also enabled by @option{-Wextra}.
 
 @item -Wsign-compare
 @opindex Wsign-compare

gcc/testsuite/ChangeLog

@@ -1,3 +1,11 @@
+2007-03-14  Dirk Mueller  <dmueller@suse.de>
+
+	* g++.dg/warn/do-empty.C: New.
+	* gcc.dg/do-empty.c: New.
+	* gcc.dg/if-empty-1.c: Update.
+	* gcc.dg/20001116-1.c: Update.
+	* gcc.dg/pr23165.c: Update.
+
 2007-03-14  Jakub Jelinek  <jakub@redhat.com>
 
 	* gfortran.dg/module_implicit_conversion.f90: New test.

gcc/testsuite/g++.dg/warn/do-empty.C

@@ -0,0 +1,15 @@
+/* Test diagnostics for empty bodies in do / while.  */
+/* { dg-do compile } */
+/* { dg-options "-Wempty-body" } */
+
+void
+f (int x)
+{
+  do
+    ; /* { dg-warning "empty body in" } */
+  while (x--);
+
+  do
+  {} /* { dg-bogus "empty body in" } */
+  while (++x < 10);
+}

gcc/testsuite/gcc.dg/20001116-1.c

@@ -7,5 +7,5 @@
 void foo (int x)
 {
   if (x)
-    ;	/* { dg-warning "empty body in an if-statement" } */
+    ;	/* { dg-warning "empty body in an" } */
 }

gcc/testsuite/gcc.dg/do-empty.c

@@ -0,0 +1,15 @@
+/* Test diagnostics for empty bodies in do / while.  */
+/* { dg-do compile } */
+/* { dg-options "-Wempty-body" } */
+
+void
+f (int x)
+{
+  do
+    ; /* { dg-warning "empty body in" } */
+  while (x--);
+
+  do
+  {} /* { dg-bogus "empty body in" } */
+  while (++x < 10);
+}

gcc/testsuite/gcc.dg/if-empty-1.c

@@ -7,7 +7,7 @@ void
 f (int x)
 {
   if (x)
-    ; /* { dg-warning "warning: empty body in an if-statement" } */
+    ; /* { dg-warning "warning: empty body in an" } */
   if (x)
     ; /* By design we don't warn in this case.  */
   else
@@ -15,7 +15,7 @@ f (int x)
   if (x)
     (void)0;
   else
-    ; /* { dg-warning "warning: empty body in an else-statement" } */
+    ; /* { dg-warning "warning: empty body in an" } */
   if (x)
     (void)0;
   else

gcc/testsuite/gcc.dg/pr23165.c

@@ -3,7 +3,7 @@
 void foo (void)
 {
 	if (0)
-	  a: ; /* { dg-warning "empty body in an if-statement" } */
+	  a: ; /* { dg-warning "empty body in an" } */
 
 
 }