From 1a32490a09a190b47b7c9c8386407505f554dd16 Mon Sep 17 00:00:00 2001
From: Alexandre Oliva <aoliva@redhat.com>
Date: Fri, 22 Apr 2005 16:57:23 +0000
Subject: [PATCH] re PR c++/21087 (ICE in do_nonmember_using_decl)

gcc/cp/ChangeLog:
PR c++/21087
* name-lookup.c (push_overloaded_decl): Do not overload with
non-duplicate anticipated built-in.
gcc/testsuite/ChangeLog:
PR c++/21087
* g++.dg/lookup/builtin2.C: New test.

From-SVN: r98570
---
 gcc/cp/ChangeLog                       |  6 ++++++
 gcc/cp/name-lookup.c                   |  7 +++++++
 gcc/testsuite/ChangeLog                |  5 +++++
 gcc/testsuite/g++.dg/lookup/builtin2.C | 19 +++++++++++++++++++
 4 files changed, 37 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/lookup/builtin2.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index bc8cb03ed47..30eb8662ea3 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2005-04-22  Alexandre Oliva  <aoliva@redhat.com>
+
+	PR c++/21087
+	* name-lookup.c (push_overloaded_decl): Do not overload with
+	non-duplicate anticipated built-in.
+
 2005-04-21  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* cp-tree.h (THROW_NAME, AUTO_VTABLE_NAME, AUTO_TEMP_FORMAT,
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index d2cf1ce3ca0..ce1d5b3b119 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -1883,6 +1883,13 @@ push_overloaded_decl (tree decl, int flags)
 	      if (duplicate_decls (decl, fn) == fn)
 		POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, fn);
 	    }
+
+	  /* We don't overload implicit built-ins.  duplicate_decls()
+	     may fail to merge the decls if the new decl is e.g. a
+	     template function.  */
+	  if (TREE_CODE (old) == FUNCTION_DECL
+	      && DECL_ANTICIPATED (old))
+	    old = NULL;
 	}
       else if (old == error_mark_node)
 	/* Ignore the undefined symbol marker.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c55ee2428d1..6b36764aa97 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2005-04-22  Alexandre Oliva  <aoliva@redhat.com>
+
+	PR c++/21087
+	* g++.dg/lookup/builtin2.C: New test.
+
 2005-04-22  Joseph S. Myers  <joseph@codesourcery.com>
 
 	* gcc.dg/weak/weak-13.c: New test.
diff --git a/gcc/testsuite/g++.dg/lookup/builtin2.C b/gcc/testsuite/g++.dg/lookup/builtin2.C
new file mode 100644
index 00000000000..be0a6f65d6c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/builtin2.C
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+
+/* PR c++/21087 */
+
+/* We used to overload the template function with the built-in
+   declaration, instead of replacing it as we should, and then barf at
+   the using decl because of a test that none of the overload set
+   members were anticipated built-ins.  */
+
+extern "C" signed int toupper(signed int __c) throw();
+namespace std
+{
+  template< typename a > a toupper(a,int){}
+  using ::toupper;
+}
+
+int f () {
+  std::toupper((signed int)'a');
+}