From: mpolacek <mpolacek@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed, 19 Sep 2018 16:59:51 +0000 (+0000)
Subject: 	PR c++/87357 - missing -Wconversion warning
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4101aa7e35ca5c18319fa494f232b6dc3649d450;p=thirdparty%2Fgcc.git

	PR c++/87357 - missing -Wconversion warning
	* decl.c (grok_op_properties): Remove diagnostic parts mentioning
	a conversion to a reference to void.  Use
	same_type_ignoring_top_level_qualifiers_p rather than comparing types
	directly.

	* g++.dg/warn/Wconversion5.C: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@264425 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 7ea4b6d0f2ef..7fcb34605c11 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2018-09-19  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/87357 - missing -Wconversion warning
+	* decl.c (grok_op_properties): Remove diagnostic parts mentioning
+	a conversion to a reference to void.  Use
+	same_type_ignoring_top_level_qualifiers_p rather than comparing types
+	directly.
+
 2018-09-18  Marek Polacek  <polacek@redhat.com>
 
 	P1064R0 - Allowing Virtual Function Calls in Constant Expressions
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 827c17203353..503b433cbd1a 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -13553,15 +13553,11 @@ grok_op_properties (tree decl, bool complain)
 	t = TYPE_MAIN_VARIANT (TREE_TYPE (t));
 
       if (VOID_TYPE_P (t))
-	warning_at (loc, OPT_Wconversion,
-		    ref
-		    ? G_("conversion to a reference to void "
-			 "will never use a type conversion operator")
-		    : G_("conversion to void "
-			 "will never use a type conversion operator"));
+	warning_at (loc, OPT_Wconversion, "conversion to void "
+		    "will never use a type conversion operator");
       else if (class_type)
 	{
-	  if (t == class_type)
+	  if (same_type_ignoring_top_level_qualifiers_p (t, class_type))
 	    warning_at (loc, OPT_Wconversion,
 			ref
 			? G_("conversion to a reference to the same type "
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c2739e8b7bbe..f52f37b6a1fa 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-09-19  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/87357 - missing -Wconversion warning
+	* g++.dg/warn/Wconversion5.C: New test.
+
 2018-09-19  Matthew Malcomson  <matthew.malcomson@arm.com>
 
 	* gcc.target/aarch64/atomic-store.c: New.
diff --git a/gcc/testsuite/g++.dg/warn/Wconversion5.C b/gcc/testsuite/g++.dg/warn/Wconversion5.C
new file mode 100644
index 000000000000..00b1ddab1883
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wconversion5.C
@@ -0,0 +1,20 @@
+// PR c++/87357
+// { dg-do compile }
+// { dg-options "-Wconversion" }
+
+struct B { };
+
+struct X : public B {
+  operator X(); // { dg-warning "3:conversion to the same type will never use a type conversion operator" }
+  operator X&(); // { dg-warning "3:conversion to a reference to the same type will never use a type conversion operator" }
+  operator X() const; // { dg-warning "3:conversion to the same type will never use a type conversion operator" }
+  operator const X(); // { dg-warning "3:conversion to the same type will never use a type conversion operator" }
+
+  operator B(); // { dg-warning "3:conversion to a base class will never use a type conversion operator" }
+  operator B&(); // { dg-warning "3:conversion to a reference to a base class will never use a type conversion operator" }
+  operator B() const; // { dg-warning "3:conversion to a base class will never use a type conversion operator" }
+  operator const B(); // { dg-warning "3:conversion to a base class will never use a type conversion operator" }
+
+  operator void(); // { dg-warning "3:conversion to void will never use a type conversion operator" }
+  operator void() const; // { dg-warning "3:conversion to void will never use a type conversion operator" }
+};