2008-09-30 Paolo Bonzini <bonzini@gnu.org>

	* c-common.c (empty_if_body_warning): Remove.
	* c-common.h (empty_if_body_warning): Remove.
	* c-parser.c (c_parser_if_body, c_parser_else_body): Implement
	here the -Wempty-body warning for `if' and `else' statements.
	* c-typeck.c (c_finish_if_stmt): Do not call empty_body_warning.

cp:
2008-09-30  Paolo Bonzini  <bonzini@gnu.org>

	* parser.c (cp_parser_selection_statement): Implement here the
	-Wempty-body warning for `if' and `else' statements.
	* semantics.c (finish_if_stmt): Do not call empty_body_warning.

testsuite:
2008-09-30  Paolo Bonzini  <bonzini@gnu.org>

	* g++.dg/warn/if-empty-1.C: Copy from gcc.dg/if-empty-1.c.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@140780 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5a9b482..68de57a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2008-09-30  Paolo Bonzini  <bonzini@gnu.org>
+
+       * c-common.c (empty_if_body_warning): Remove.
+       * c-common.h (empty_if_body_warning): Remove.
+       * c-parser.c (c_parser_if_body, c_parser_else_body): Implement
+       here the -Wempty-body warning for `if' and `else' statements.
+       * c-typeck.c (c_finish_if_stmt): Do not call empty_body_warning.
+
 2008-09-29  H.J. Lu  <hongjiu.lu@intel.com>
 
        * config/i386/i386.opt: Add msse2avx.

diff --git a/gcc/c-common.c b/gcc/c-common.c
index 5d69211..7665b62 100644 (file)
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -1291,31 +1291,6 @@ strict_aliasing_warning (tree otype, tree type, tree expr)
   return false;
 }
 
-/* Print a warning about if (); or if () .. else; constructs
-   via the special empty statement node that we create.  INNER_THEN
-   and INNER_ELSE are the statement lists of the if and the else
-   block.  */
-
-void
-empty_if_body_warning (tree inner_then, tree inner_else)
-{
-  if (TREE_CODE (inner_then) == STATEMENT_LIST
-      && STATEMENT_LIST_TAIL (inner_then))
-    inner_then = STATEMENT_LIST_TAIL (inner_then)->stmt;
-
-  if (inner_else && TREE_CODE (inner_else) == STATEMENT_LIST
-      && STATEMENT_LIST_TAIL (inner_else))
-    inner_else = STATEMENT_LIST_TAIL (inner_else)->stmt;
-
-  if (IS_EMPTY_STMT (inner_then) && !inner_else)
-    warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
-             "in an %<if%> statement", EXPR_LOCUS (inner_then));
-
-  else if (inner_else && IS_EMPTY_STMT (inner_else))
-    warning (OPT_Wempty_body, "%Hsuggest braces around empty body "
-             "in an %<else%> statement", EXPR_LOCUS (inner_else));
-}
-
 /* Warn for unlikely, improbable, or stupid DECL declarations
    of `main'.  */
 

diff --git a/gcc/c-common.h b/gcc/c-common.h
index 15ea573..622100a 100644 (file)
--- a/gcc/c-common.h
+++ b/gcc/c-common.h
@@ -726,7 +726,6 @@ struct varray_head_tag;
 extern void constant_expression_warning (tree);
 extern void constant_expression_error (tree);
 extern bool strict_aliasing_warning (tree, tree, tree);
-extern void empty_if_body_warning (tree, tree);
 extern void warnings_for_convert_and_check (tree, tree, tree);
 extern tree convert_and_check (tree, tree);
 extern void overflow_warning (tree);

diff --git a/gcc/c-parser.c b/gcc/c-parser.c
index 2b64c86..9597660 100644 (file)
--- a/gcc/c-parser.c
+++ b/gcc/c-parser.c
@@ -3858,8 +3858,12 @@ c_parser_if_body (c_parser *parser, bool *if_p)
   *if_p = c_parser_next_token_is_keyword (parser, RID_IF);
   if (c_parser_next_token_is (parser, CPP_SEMICOLON))
     {
+      location_t loc = c_parser_peek_token (parser)->location;
       add_stmt (build_empty_stmt ());
       c_parser_consume_token (parser);
+      if (!c_parser_next_token_is_keyword (parser, RID_ELSE))
+       warning_at (loc, OPT_Wempty_body,
+                   "suggest braces around empty body in an %<if%> statement");
     }
   else if (c_parser_next_token_is (parser, CPP_OPEN_BRACE))
     add_stmt (c_parser_compound_statement (parser));
@@ -3883,6 +3887,9 @@ c_parser_else_body (c_parser *parser)
     c_parser_label (parser);
   if (c_parser_next_token_is (parser, CPP_SEMICOLON))
     {
+      warning_at (c_parser_peek_token (parser)->location,
+                 OPT_Wempty_body,
+                "suggest braces around empty body in an %<else%> statement");
       add_stmt (build_empty_stmt ());
       c_parser_consume_token (parser);
     }

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index 1424405..c6474ed 100644 (file)
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -7440,8 +7440,6 @@ c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
                  &if_locus);
     }
 
-  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);
   add_stmt (stmt);

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 8c722d8..5e5c742 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2008-09-30  Paolo Bonzini  <bonzini@gnu.org>
+
+       * parser.c (cp_parser_selection_statement): Implement here the
+       -Wempty-body warning for `if' and `else' statements.
+       * semantics.c (finish_if_stmt): Do not call empty_body_warning.
+
 2008-09-25  Paolo Carlini  <paolo.carlini@oracle.com>
 
        PR c++/37649

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index f28c76d..c368a1c 100644 (file)
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -7155,7 +7155,17 @@ cp_parser_selection_statement (cp_parser* parser, bool *if_p)
            /* Parse the then-clause.  */
            in_statement = parser->in_statement;
            parser->in_statement |= IN_IF_STMT;
-           cp_parser_implicitly_scoped_statement (parser, &nested_if);
+           if (cp_lexer_next_token_is (parser->lexer, CPP_SEMICOLON))
+             {
+               location_t loc = cp_lexer_peek_token (parser->lexer)->location;
+               add_stmt (build_empty_stmt ());
+               cp_lexer_consume_token (parser->lexer);
+               if (!cp_lexer_next_token_is_keyword (parser->lexer, RID_ELSE))
+                 warning_at (loc, OPT_Wempty_body, "suggest braces around "
+                             "empty body in an %<if%> statement");
+             }
+           else
+             cp_parser_implicitly_scoped_statement (parser, &nested_if);
            parser->in_statement = in_statement;
 
            finish_then_clause (statement);
@@ -7168,7 +7178,17 @@ cp_parser_selection_statement (cp_parser* parser, bool *if_p)
                cp_lexer_consume_token (parser->lexer);
                begin_else_clause (statement);
                /* Parse the else-clause.  */
-               cp_parser_implicitly_scoped_statement (parser, NULL);
+               if (cp_lexer_next_token_is (parser->lexer, CPP_SEMICOLON))
+                 {
+                   warning_at (cp_lexer_peek_token (parser->lexer)->location,
+                               OPT_Wempty_body, "suggest braces around "
+                               "empty body in an %<else%> statement");
+                   add_stmt (build_empty_stmt ());
+                   cp_lexer_consume_token (parser->lexer);
+                 }
+               else
+                 cp_parser_implicitly_scoped_statement (parser, NULL);
+
                finish_else_clause (statement);
 
                /* If we are currently parsing a then-clause, then

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 176a7fd..13e9a0f 100644 (file)
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -695,7 +695,6 @@ finish_if_stmt (tree if_stmt)
   TREE_CHAIN (if_stmt) = NULL;
   add_stmt (do_poplevel (scope));
   finish_stmt ();
-  empty_if_body_warning (THEN_CLAUSE (if_stmt), ELSE_CLAUSE (if_stmt));
 }
 
 /* Begin a while-statement.  Returns a newly created WHILE_STMT if

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index df91766..28086b3 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,9 @@
 2008-09-30  Paolo Bonzini  <bonzini@gnu.org>
 
+       * g++.dg/warn/if-empty-1.C: Copy from gcc.dg/if-empty-1.c.
+
+2008-09-30  Paolo Bonzini  <bonzini@gnu.org>
+
        PR testsuite/36891
        PR testsuite/37675
        * gcc.dg/torture/pr36891.c: Add -msse on 32-bit i386.

diff --git a/gcc/testsuite/g++.dg/warn/if-empty-1.C b/gcc/testsuite/g++.dg/warn/if-empty-1.C
new file mode 100644 (file)
index 0000000..b29a6cb
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/if-empty-1.C
@@ -0,0 +1,23 @@
+/* Test diagnostics for empty bodies in if / else.  */
+/* Origin: Joseph Myers <joseph@codesourcery.com> */
+/* { dg-do compile } */
+/* { dg-options "-Wempty-body" } */
+
+void
+f (int x)
+{
+  if (x)
+    ; /* { dg-warning "suggest braces around empty body in an" } */
+  if (x)
+    ; /* By design we don't warn in this case.  */
+  else
+    (void)0;
+  if (x)
+    (void)0;
+  else
+    ; /* { dg-warning "suggest braces around empty body in an" } */
+  if (x)
+    (void)0;
+  else
+    (void)0;
+}