re PR c++/5310 (Weird warnings about using (int)NULL)

2007-11-23  Mark Mitchell  <mark@codesourcery.com>
	    Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
	
	PR c++/5310
cp/
	* call.c (convert_like_real): Build a zero constant when __null is
	converted to an integer type.
testsuite/
	* g++.dg/warn/pr5310.C: New.
	* g++.dg/warn/pr33160.C: New

Co-Authored-By: Manuel López-Ibáñez <manu@gcc.gnu.org>

From-SVN: r130381

gcc/cp/ChangeLog

+2007-11-23  Mark Mitchell  <mark@codesourcery.com>
+	    Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+	
+	PR c++/5310
+	* call.c (convert_like_real): Build a zero constant when __null is
+	converted to an integer type.
+	
 2007-11-22  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/34094

gcc/cp/call.c

@@ -4420,7 +4420,14 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
 	 about to bind it to a reference, in which case we need to
 	 leave it as an lvalue.  */
       if (inner >= 0)
-	expr = decl_constant_value (expr);
+        {   
+          expr = decl_constant_value (expr);
+          if (expr == null_node && INTEGRAL_TYPE_P (totype))
+            /* If __null has been converted to an integer type, we do not
+               want to warn about uses of EXPR as an integer, rather than
+               as a pointer.  */
+            expr = build_int_cst (totype, 0);
+        }
       return expr;
     case ck_ambig:
       /* Call build_user_type_conversion again for the error.  */

gcc/testsuite/ChangeLog

+2007-11-23  Mark Mitchell  <mark@codesourcery.com>
+	    Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+	
+	PR c++/5310
+	* g++.dg/warn/pr5310.C: New.
+	* g++.dg/warn/pr33160.C: New.
+	
 2007-11-23  Richard Guenther  <rguenther@suse.de>
 	Michael Matz  <matz@suse.de>
 

gcc/testsuite/g++.dg/warn/pr33160.C

+// PR 33160
+// { dg-do compile }
+// { dg-options "-Wall -Wextra -Wpointer-arith -pedantic -Wconversion" }
+
+typedef int __attribute__((mode(pointer))) intptr_t;
+int foo(void)
+{
+ intptr_t t = 0;
+ if (t != ((intptr_t)__null)) t = 1;
+ return 0;
+}
+

gcc/testsuite/g++.dg/warn/pr5310.C

+// PR 5310
+// { dg-do compile }
+// { dg-options "-pedantic -Wall -Wextra -Wpointer-arith -Wconversion" } 
+void foo (int);
+void foo (long);
+
+void bar()
+{
+   foo ((int)__null);
+   foo ((long)__null);
+}