From: Simon Martin <simartin@users.sourceforge.net>
Date: Fri, 12 Oct 2007 18:43:33 +0000 (+0000)
Subject: re PR c++/26698 (g++ accepts const-incorrect code due to conversion function)
X-Git-Tag: releases/gcc-4.3.0~2073
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a9a81e7d6a50fc249f22af07504e9620f93d6037;p=thirdparty%2Fgcc.git

re PR c++/26698 (g++ accepts const-incorrect code due to conversion function)

gcc/cp/

2007-10-12  Simon Martin  <simartin@users.sourceforge.net>

	PR c++/26698
	* call.c (build_user_type_conversion_1): Do not consider conversion
	functions to convert a (possibly cv-qualified) object to the (possibly
	cv-qualified) same object type (or a reference to it), to a (possibly
	cv-qualified) base class of that type (or a reference to it).

gcc/testsuite/

2007-10-12  Simon Martin  <simartin@users.sourceforge.net>

	PR c++/26698
	* g++.dg/conversion/op4.C: New test.

From-SVN: r129274
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 075e2096dc93..bc25402a0e9d 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2007-10-12  Simon Martin  <simartin@users.sourceforge.net>
+
+	PR c++/26698
+	* call.c (build_user_type_conversion_1): Do not consider conversion
+	functions to convert a (possibly cv-qualified) object to the (possibly
+	cv-qualified) same object type (or a reference to it), to a (possibly
+	cv-qualified) base class of that type (or a reference to it).
+
 2007-10-12  Paolo Carlini  <pcarlini@suse.de>
 
 	* pt.c (tsubst): Use template_parm_level_and_index.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index cf3aea7e9594..6ca0a957f425 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -2601,7 +2601,21 @@ build_user_type_conversion_1 (tree totype, tree expr, int flags)
     ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
 
   if (IS_AGGR_TYPE (fromtype))
-    conv_fns = lookup_conversions (fromtype);
+    {
+      tree to_nonref = non_reference (totype);
+      if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
+	  (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
+	   && DERIVED_FROM_P (to_nonref, fromtype)))
+	{
+	  /* [class.conv.fct] A conversion function is never used to
+	     convert a (possibly cv-qualified) object to the (possibly
+	     cv-qualified) same object type (or a reference to it), to a
+	     (possibly cv-qualified) base class of that type (or a
+	     reference to it)...  */
+	}
+      else
+	conv_fns = lookup_conversions (fromtype);
+    }
 
   candidates = 0;
   flags |= LOOKUP_NO_CONVERSION;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0b3aa07d3ac1..6b0c2f82c34e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2007-10-12  Simon Martin  <simartin@users.sourceforge.net>
+
+	PR c++/26698
+	* g++.dg/conversion/op4.C: New test.
+
 2007-10-12  Richard Sandiford  <rsandifo@nildram.co.uk>
 
 	* g++.dg/torture/pr33572.C (main): Allow argc to be zero.
diff --git a/gcc/testsuite/g++.dg/conversion/op4.C b/gcc/testsuite/g++.dg/conversion/op4.C
new file mode 100644
index 000000000000..164bbcdc4131
--- /dev/null
+++ b/gcc/testsuite/g++.dg/conversion/op4.C
@@ -0,0 +1,19 @@
+/* PR c++/26698 */
+/* { dg-do "compile" } */
+
+struct X {
+  int x;
+  X (int i = 0) : x (i) {}
+  operator X& (void) const {
+    return *(new X);
+  }
+};
+
+void add_one (X & ref) { /* { dg-error "in passing argument" } */
+  ++ ref.x;
+}
+
+void foo() {
+  X const a (2);
+  add_one(a); /* { dg-error "invalid initialization of reference of type" } */
+}