From: Simon Martin <simartin@users.sourceforge.net>
Date: Sat, 13 Oct 2007 06:04:57 +0000 (+0000)
Subject: re PR c++/26698 (g++ accepts const-incorrect code due to conversion function)
X-Git-Tag: prereleases/gcc-4.2.3-rc1~190
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=59a85808a9d5e8c167086e02250929943ce82f8e;p=thirdparty%2Fgcc.git

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

gcc/cp/

2007-10-13  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/

2007-10-13  Simon Martin  <simartin@users.sourceforge.net>

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

From-SVN: r129282
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 5a8ecbcbe35b..e884dc47c69b 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2007-10-13  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).
+
 2007-10-09  Jason Merrill  <jason@redhat.com>
 
 	PR c++/32470
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 891ebb96829c..244cab1c1f34 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -2550,7 +2550,21 @@ 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 7ffdf38aec72..6de4856501f7 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2007-10-13  Simon Martin  <simartin@users.sourceforge.net>
+
+	PR c++/26698
+	* g++.dg/conversion/op4.C: New test.
+
 2007-10-12  Zdenek Dvorak <ook@ucw.cz>
 
 	PR tree-optimization/33714
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" } */
+}