re PR c++/17880 (-Wsequence-point doesn't warn inside if, while, do conditions,…

re PR c++/17880 (-Wsequence-point doesn't warn inside if, while, do conditions, for beg/cond/end expressions etc.)

2008-08-09  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>

	PR c/17880
	* c-typeck.c (digest_init): Call verify_sequence_points from here.
	(c_finish_return): Likewise.
	(c_start_case): Likewise.
	* c-common.c (warn_for_collisions_1): Use explicit location in
	warning.
	* c-parser.c (c_parser_condition): New. Call
	verify_sequence_points.
	(c_parser_paren_condition): Call c_parser_condition.
	(c_parser_for_statement): Call c_parser_condition.
testsuite/
	* gcc.dg/sequence-pt-pr17880.c: New.

From-SVN: r138904

gcc/ChangeLog

 2008-08-09  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
 
+	PR c/17880
+	* c-typeck.c (digest_init): Call verify_sequence_points from here.
+	(c_finish_return): Likewise.
+	(c_start_case): Likewise.
+	* c-common.c (warn_for_collisions_1): Use explicit location in
+	warning.
+	* c-parser.c (c_parser_condition): New. Call
+	verify_sequence_points.
+	(c_parser_paren_condition): Call c_parser_condition.
+	(c_parser_for_statement): Call c_parser_condition.
+
+2008-08-09  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+
 	PR 36901
 	* diagnostic.def (DK_PEDWARN, DK_PERMERROR): New.  
 	* diagnostic.c (pedantic_warning_kind, permissive_error_kind):

gcc/c-common.c

@@ -1902,8 +1902,10 @@ warn_for_collisions_1 (tree written, tree writer, struct tlist *list,
 	  && DECL_NAME (list->expr))
 	{
 	  warned_ids = new_tlist (warned_ids, written, NULL_TREE);
-	  warning (OPT_Wsequence_point, "operation on %qE may be undefined",
-		   list->expr);
+	  warning_at (EXPR_HAS_LOCATION (writer)
+		      ? EXPR_LOCATION (writer) : input_location,
+		      OPT_Wsequence_point, "operation on %qE may be undefined",
+		      list->expr);
 	}
       list = list->next;
     }

gcc/c-parser.c

@@ -3791,6 +3791,23 @@ c_parser_statement_after_labels (c_parser *parser)
   parser->in_if_block = in_if_block;
 }
 
+/* Parse the condition from an if, do, while or for statements.  */
+
+static tree
+c_parser_condition (c_parser *parser)
+{
+  location_t loc;
+  tree cond;
+  loc = c_parser_peek_token (parser)->location;
+  cond = c_objc_common_truthvalue_conversion 
+    (c_parser_expression_conv (parser).value);
+  if (CAN_HAVE_LOCATION_P (cond))
+    SET_EXPR_LOCATION (cond, loc);
+  if (warn_sequence_point)
+    verify_sequence_points (cond);
+  return cond;
+}
+
 /* Parse a parenthesized condition from an if, do or while statement.
 
    condition:
@@ -3799,15 +3816,10 @@ c_parser_statement_after_labels (c_parser *parser)
 static tree
 c_parser_paren_condition (c_parser *parser)
 {
-  location_t loc;
   tree cond;
   if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
     return error_mark_node;
-  loc = c_parser_peek_token (parser)->location;
-  cond = c_objc_common_truthvalue_conversion
-    (c_parser_expression_conv (parser).value);
-  if (CAN_HAVE_LOCATION_P (cond))
-    SET_EXPR_LOCATION (cond, loc);
+  cond = c_parser_condition (parser);
   c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, "expected %<)%>");
   return cond;
 }
@@ -4073,7 +4085,6 @@ c_parser_for_statement (c_parser *parser)
 	  c_parser_skip_until_found (parser, CPP_SEMICOLON, "expected %<;%>");
 	}
       /* Parse the loop condition.  */
-      loc = c_parser_peek_token (parser)->location;
       if (c_parser_next_token_is (parser, CPP_SEMICOLON))
 	{
 	  c_parser_consume_token (parser);
@@ -4081,10 +4092,7 @@ c_parser_for_statement (c_parser *parser)
 	}
       else
 	{
-	  tree ocond = c_parser_expression_conv (parser).value;
-	  cond = c_objc_common_truthvalue_conversion (ocond);
-	  if (CAN_HAVE_LOCATION_P (cond))
-	    SET_EXPR_LOCATION (cond, loc);
+	  cond = c_parser_condition (parser);
 	  c_parser_skip_until_found (parser, CPP_SEMICOLON, "expected %<;%>");
 	}
       /* Parse the increment expression.  */

gcc/c-typeck.c

@@ -4801,6 +4801,9 @@ digest_init (tree type, tree init, bool strict_string, int require_constant)
 	}
     }
 
+  if (warn_sequence_point)
+    verify_sequence_points (inside_init);
+
   /* Any type can be initialized
      from an expression of the same type, optionally with braces.  */
 
@@ -7166,6 +7169,9 @@ c_finish_return (tree retval)
 	}
 
       retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
+
+      if (warn_sequence_point)
+	verify_sequence_points (retval);
     }
 
   ret_stmt = build_stmt (RETURN_EXPR, retval);
@@ -7243,6 +7249,9 @@ c_start_case (tree exp)
 		     "converted to %<int%> in ISO C");
 
 	  exp = default_conversion (exp);
+
+	  if (warn_sequence_point)
+	    verify_sequence_points (exp);
 	}
     }
 

gcc/testsuite/ChangeLog

 2008-08-09  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
 
+	PR c/17880
+	* gcc.dg/sequence-pt-pr17880.c: New.
+
+2008-08-09  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+
 	PR c++/12242
 	* g++.dg/warn/pr12242.C: New.
 	

gcc/testsuite/gcc.dg/sequence-pt-pr17880.c

+/* PR 17880 */
+/* { dg-do compile } */
+/* { dg-options "-Wsequence-point" } */
+
+int
+foo (int x)
+{
+  unsigned int a;
+  int b;
+
+  b = (a += 5) > a;  /* { dg-warning "undefined" "sequence point warning" } */
+  b = (a += 5) + a == 10;  /* { dg-warning "undefined" "sequence point warning" } */
+  b = (a -= 5) > a;  /* { dg-warning "undefined" "sequence point warning" } */
+  b = (a -= 5) + a == 10;  /* { dg-warning "undefined" "sequence point warning" } */
+  b = a-- > a;  /* { dg-warning "undefined" "sequence point warning" } */
+  b = a-- + a == 10;  /* { dg-warning "undefined" "sequence point warning" } */
+  b = ++a > a;  /* { dg-warning "undefined" "sequence point warning" } */
+  b = ++a + a == 10;  /* { dg-warning "undefined" "sequence point warning" } */
+
+  if ((a += 5) > a) return -1;  /* { dg-warning "undefined" "sequence point warning" } */
+  if ((a += 5) + a == 10) return -1;  /* { dg-warning "undefined" "sequence point warning" } */
+  if ((a -= 5) > a) return -1;  /* { dg-warning "undefined" "sequence point warning" } */
+  if ((a -= 5) + a == 10) return -1;  /* { dg-warning "undefined" "sequence point warning" } */
+  if (a-- > a) return -1;  /* { dg-warning "undefined" "sequence point warning" } */
+  if (a-- + a == 10) return -1;  /* { dg-warning "undefined" "sequence point warning" } */
+  if (++a > a) return -1;  /* { dg-warning "undefined" "sequence point warning" } */
+  if (++a + a == 10) return -1;  /* { dg-warning "undefined" "sequence point warning" } */
+  do {} while ((a += 5) > a);  /* { dg-warning "undefined" "sequence point warning" } */
+  while ((a += 5) > a);  /* { dg-warning "undefined" "sequence point warning" } */
+  for ((a += 5) > a;;);  /* { dg-warning "undefined" "sequence point warning" } */
+  for (b = (a += 5) > a;;);  /* { dg-warning "undefined" "sequence point warning" } */
+  for (; (a += 5) > a;);  /* { dg-warning "undefined" "sequence point warning" } */
+  for (;; b = (a += 5) > a);  /* { dg-warning "undefined" "sequence point warning" } */
+  for (;; a++ + a++);  /* { dg-warning "undefined" "sequence point warning" } */
+  if (a) a++ - a--;    /* { dg-warning "undefined" "sequence point warning" } */
+  ((a +=5) > a) ? a : b; /* { dg-warning "undefined" "sequence point warning" } */
+  return (a++ - a--); /* { dg-warning "undefined" "sequence point warning" } */
+}
+
+void bar (int i)
+{
+  int a = i++ - i++; /* { dg-warning "undefined" "sequence point warning" } */
+} 
+
+void baz (int i)
+{
+  switch (i++ + i++)  /* { dg-warning "undefined" "sequence point warning" } */
+    {
+    case 1:
+      i++ - i++;  /* { dg-warning "undefined" "sequence point warning" } */
+    case 2:
+      break;
+    }
+}