From: David Ayers <ayers@fsfe.org>
Date: Thu, 2 Apr 2009 12:40:48 +0000 (+0000)
Subject: re PR objc/27377 (false compiler warnings generated in Objective-C code)
X-Git-Tag: releases/gcc-4.3.4~247
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=af6087c2f10c57efceb3a9278252fcbaa2f59030;p=thirdparty%2Fgcc.git

re PR objc/27377 (false compiler warnings generated in Objective-C code)

gcc/
2009-03-29  David Ayers  <ayers@fsfe.org>

	PR objc/27377
	* c-typeck.c (build_conditional_expr): Emit ObjC warnings
	by calling objc_compare_types and surpress warnings about
	incompatible C pointers that are compatible ObjC pointers.

gcc/testsuite/
2009-03-29  David Ayers  <ayers@fsfe.org>

	PR objc/27377
	* objc.dg/conditional-1.m: New tests.

From-SVN: r145446
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7adac9c10519..f9e5fb95b320 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2009-04-02  David Ayers  <ayers@fsfe.org>
+ 
+	PR objc/27377
+	* c-typeck.c (build_conditional_expr): Emit ObjC warnings
+	by calling objc_compare_types and surpress warnings about
+	incompatible C pointers that are compatible ObjC pointers.
+	
 2009-04-01  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR rtl-optimization/39588
diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index 877918437b00..c96f738ee3a7 100644
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -3393,6 +3393,7 @@ build_conditional_expr (tree ifexp, tree op1, tree op2)
   enum tree_code code2;
   tree result_type = NULL;
   tree orig_op1 = op1, orig_op2 = op2;
+  bool objc_ok;
 
   /* Promote both alternatives.  */
 
@@ -3419,6 +3420,8 @@ build_conditional_expr (tree ifexp, tree op1, tree op2)
       return error_mark_node;
     }
 
+  objc_ok = objc_compare_types (type1, type2, -3, NULL_TREE);
+
   /* Quickly detect the usual case where op1 and op2 have the same type
      after promotion.  */
   if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
@@ -3499,7 +3502,8 @@ build_conditional_expr (tree ifexp, tree op1, tree op2)
 	}
       else
 	{
-	  pedwarn ("pointer type mismatch in conditional expression");
+	  if (!objc_ok)
+	    pedwarn ("pointer type mismatch in conditional expression");
 	  result_type = build_pointer_type (void_type_node);
 	}
     }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 1ab4b0eb58e4..e104e88781a8 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2009-04-02  David Ayers  <ayers@fsfe.org>
+
+	PR objc/27377
+	* objc.dg/conditional-1.m: New tests.
+	
 2009-04-01  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc.c-torture/compile/20090401-1.c: New test.
diff --git a/gcc/testsuite/objc.dg/conditional-1.m b/gcc/testsuite/objc.dg/conditional-1.m
new file mode 100644
index 000000000000..0aad62c55f18
--- /dev/null
+++ b/gcc/testsuite/objc.dg/conditional-1.m
@@ -0,0 +1,45 @@
+/* Testing conditional warnings (without headers).  */
+/* Author: David Ayers */
+
+/* { dg-do compile } */
+
+#define nil ((id)0)
+@interface MyObject
+@end
+
+@protocol MyProtocol
+@end
+
+@interface MyProtoObject <MyProtocol>
+@end
+
+
+int
+main (int argc, char *argv[])
+{
+  id var_id = nil;
+  id <MyProtocol> var_id_p = nil;
+  MyObject *var_obj = nil;
+  MyProtoObject *var_obj_p = nil;
+
+  var_id = (var_id == var_obj) ? var_id : var_obj;
+  var_id = (var_id == var_obj) ? var_id : var_obj_p;
+
+  /* Ayers: Currently, the following test case passes for
+     technically the wrong reason (see below).
+  */
+  var_obj_p = (var_id == var_obj) ? var_obj_p : var_obj; /* { dg-warning "distinct Objective-C types" } */
+  var_obj_p = (var_id == var_obj) ? var_obj_p : var_id_p;
+
+  /* Ayers: The first of the following test cases
+     should probably warn for var_obj_p = var_obj,
+     yet that would require extensive changes to
+     build_conditional_expr to create a tree with
+     multiple types that the assignment would have
+     to evaluate both versions for correct diagnostics.
+  */
+  var_obj_p = (var_id == var_obj) ? var_id : var_obj;  
+  var_obj_p = (var_id == var_obj) ? var_id : var_obj_p;
+
+  return 0;
+}