From cc85b4c564805534a69a0c23999c3e2c32d904b8 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 19 Feb 2008 17:53:07 -0500
Subject: [PATCH] re PR c++/34950 (ICE in svn boost math toolkit)

        PR c++/34950
        * pt.c (resolve_overloaded_unification): Set processing_template_decl
        while we look for possible bindings.

From-SVN: r132455
---
 gcc/cp/ChangeLog                              |  6 ++++++
 gcc/cp/pt.c                                   |  2 ++
 .../g++.dg/template/explicit-args1.C          | 21 +++++++++++++++++++
 3 files changed, 29 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/template/explicit-args1.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 6f016fcfce5..81a243a1354 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2008-02-19  Jason Merrill  <jason@redhat.com>
+
+	PR c++/34950
+	* pt.c (resolve_overloaded_unification): Set processing_template_decl
+	while we look for possible bindings.
+
 2008-02-19  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/35028
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 5931126e860..e45f6da91e7 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -12137,6 +12137,7 @@ resolve_overloaded_unification (tree tparms,
 	  if (TREE_CODE (fn) != TEMPLATE_DECL)
 	    continue;
 
+	  ++processing_template_decl;
 	  subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
 				  expl_subargs, /*check_ret=*/false);
 	  if (subargs)
@@ -12145,6 +12146,7 @@ resolve_overloaded_unification (tree tparms,
 	      good += try_one_overload (tparms, targs, tempargs, parm,
 					elem, strict, sub_strict, addr_p);
 	    }
+	  --processing_template_decl;
 	}
     }
   else if (TREE_CODE (arg) != OVERLOAD
diff --git a/gcc/testsuite/g++.dg/template/explicit-args1.C b/gcc/testsuite/g++.dg/template/explicit-args1.C
new file mode 100644
index 00000000000..10d59e15734
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/explicit-args1.C
@@ -0,0 +1,21 @@
+// PR c++/34950
+
+template <class T = int> struct policy {
+    typedef int unnecessary;
+};
+
+template <class Policy> struct A {
+    typedef int type;
+    typedef typename Policy::unnecessary unused;
+};
+
+template <class T> struct S {
+    typedef int type;
+    typedef typename A<T>::type unused;
+};
+
+template <class, class T> typename S<T>::type         foo();
+template <class>                   S<policy<> >::type foo();
+
+template <typename T> int def(T);
+const int i = def(foo<int>);
-- 
2.30.2