re PR other/30465 (Duplicated overflow warning)

2007-03-04  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>

	PR other/30465
	* c-common.c (convert_and_check): Don't give warnings for
	conversion if 'expr' already overflowed.

testsuite/
	* gcc.dg/multiple-overflow-warn-3.c: New.
	* g++.dg/warn/multiple-overflow-warn-3.C: New.

From-SVN: r122534

gcc/ChangeLog

+2007-03-04  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+
+	PR other/30465
+	* c-common.c (convert_and_check): Don't give warnings for
+	conversion if 'expr' already overflowed.
+	
 2007-03-04  Roger Sayle  <roger@eyesopen.com>
 
 	PR middle-end/30744

gcc/c-common.c

@@ -1250,10 +1250,9 @@ convert_and_check (tree type, tree expr)
   
   result = convert (type, expr);
 
-  if (skip_evaluation)
+  if (skip_evaluation || TREE_OVERFLOW_P (expr))
     return result;
 
-
   if (TREE_CODE (expr) == INTEGER_CST
       && (TREE_CODE (type) == INTEGER_TYPE
           || TREE_CODE (type) == ENUMERAL_TYPE)
@@ -1274,21 +1273,19 @@ convert_and_check (tree type, tree expr)
           else if (warn_conversion)
             conversion_warning (type, expr);
         }
-      else
-        {
-          if (!int_fits_type_p (expr, c_common_unsigned_type (type)))
-            warning (OPT_Woverflow,
-                     "overflow in implicit constant conversion");
-          /* No warning for converting 0x80000000 to int.  */
-          else if (pedantic
-                   && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
-                       || TYPE_PRECISION (TREE_TYPE (expr))
-                       != TYPE_PRECISION (type)))
-            warning (OPT_Woverflow,
-                     "overflow in implicit constant conversion");
-          else if (warn_conversion)
-            conversion_warning (type, expr);
-        }
+      else if (!int_fits_type_p (expr, c_common_unsigned_type (type))) 
+	warning (OPT_Woverflow,
+		 "overflow in implicit constant conversion");
+      /* No warning for converting 0x80000000 to int.  */
+      else if (pedantic
+	       && (TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE
+		   || TYPE_PRECISION (TREE_TYPE (expr))
+		   != TYPE_PRECISION (type)))
+	warning (OPT_Woverflow,
+		 "overflow in implicit constant conversion");
+
+      else if (warn_conversion)
+	conversion_warning (type, expr);
     }
   else if (TREE_CODE (result) == INTEGER_CST && TREE_OVERFLOW (result)) 
     warning (OPT_Woverflow,

gcc/testsuite/ChangeLog

+2007-03-04  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+
+	PR other/30465
+	* gcc.dg/multiple-overflow-warn-3.c: New.
+	* g++.dg/warn/multiple-overflow-warn-3.C: New.
+	
 2007-03-04  Simon Martin  <simartin@users.sourceforge.net>
 
 	PR c++/30895

gcc/testsuite/g++.dg/warn/multiple-overflow-warn-3.C

+/* PR 30465 : Test for duplicated warnings in a conversion.  */
+/* { dg-do compile } */
+/* { dg-options "-Woverflow" } */
+
+wchar_t
+g (void)
+{
+  wchar_t wc = ((wchar_t)1 << 31) - 1; /* { dg-bogus "overflow .* overflow" } */
+  /* { dg-warning "overflow" "" { target *-*-* } 8 } */
+  return wc;
+}
+

gcc/testsuite/gcc.dg/multiple-overflow-warn-3.c

+/* PR 30465 : Test for duplicated warnings in a conversion.  */
+/* { dg-do compile } */
+/* { dg-options "-Woverflow" } */
+
+short int
+g (void)
+{
+  short int wc = ((short int)1 << 31) - 1; /* { dg-bogus "overflow .* overflow" } */
+  /* { dg-warning "overflow" "" { target *-*-* } 8 } */
+  return wc;
+}
+