From 54864ec68854296d0d0dda4840e65c86a2af11f4 Mon Sep 17 00:00:00 2001
From: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed, 23 Aug 2006 14:04:24 +0000
Subject:         PR c++/28687         * rtti.c (build_dynamic_cast,
 build_dynamic_cast_1):         Move -fno-rtti check to be more specific.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@116350 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/cp/ChangeLog                            |  6 ++++++
 gcc/cp/rtti.c                               | 14 +++++++-------
 gcc/doc/invoke.texi                         |  4 +++-
 gcc/testsuite/g++.dg/rtti/no-rtti-voidptr.C | 21 +++++++++++++++++++++
 4 files changed, 37 insertions(+), 8 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/rtti/no-rtti-voidptr.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index ff60084b83c..e2bc2dbb525 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2006-08-11   Benjamin Smedberg <benjamin@smedbergs.us>
+
+	PR c++/28687
+	* rtti.c (build_dynamic_cast, build_dynamic_cast_1):
+	Move -fno-rtti check to be more specific.
+
 2006-08-22  Jason Merrill  <jason@redhat.com>
 
 	PR c++/23372
diff --git a/gcc/cp/rtti.c b/gcc/cp/rtti.c
index 18beb7906f9..b4cede48b06 100644
--- a/gcc/cp/rtti.c
+++ b/gcc/cp/rtti.c
@@ -619,6 +619,13 @@ build_dynamic_cast_1 (tree type, tree expr)
 		}
 	    }
 
+	  /* Use of dynamic_cast when -fno-rtti is prohibited.  */
+	  if (!flag_rtti)
+	    {
+	      error ("%<dynamic_cast%> not permitted with -fno-rtti");
+	      return error_mark_node;
+	    }
+
 	  target_type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
 	  static_type = TYPE_MAIN_VARIANT (TREE_TYPE (exprtype));
 	  td2 = get_tinfo_decl (target_type);
@@ -704,13 +711,6 @@ build_dynamic_cast (tree type, tree expr)
   if (type == error_mark_node || expr == error_mark_node)
     return error_mark_node;
 
-  /* Use of dynamic_cast when -fno-rtti is prohibited.  */
-  if (!flag_rtti)
-    {
-      error ("%<dynamic_cast%> not permitted with -fno-rtti");
-      return error_mark_node;
-    }
-
   if (processing_template_decl)
     {
       expr = build_min (DYNAMIC_CAST_EXPR, type, expr);
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index c9b25f754db..d7f0826fca4 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -1569,7 +1569,9 @@ functions for use by the C++ runtime type identification features
 (@samp{dynamic_cast} and @samp{typeid}).  If you don't use those parts
 of the language, you can save some space by using this flag.  Note that
 exception handling uses the same information, but it will generate it as
-needed.
+needed. The @samp{dynamic_cast} operator can still be used for casts that
+do not require runtime type information, i.e. casts to @code{void *} or to
+unambiguous base classes.
 
 @item -fstats
 @opindex fstats
diff --git a/gcc/testsuite/g++.dg/rtti/no-rtti-voidptr.C b/gcc/testsuite/g++.dg/rtti/no-rtti-voidptr.C
new file mode 100644
index 00000000000..2b3915d179c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/rtti/no-rtti-voidptr.C
@@ -0,0 +1,21 @@
+// { dg-do compile }
+// { dg-options "-fno-rtti" }
+
+// PR C++/28687
+
+struct A {
+  virtual ~A() { }
+};
+
+struct B : A {
+};
+
+A* f()
+{
+  return new B();
+}
+
+int main()
+{
+  void* b = dynamic_cast<void*>(f());
+}
-- 
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