PR c++/35255

	* pt.c (resolve_overloaded_unification): Fix DR 115 handling.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@175367 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index c7e39be..e00b400 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2011-06-23  Jason Merrill  <jason@redhat.com>
+
+       PR c++/35255
+       * pt.c (resolve_overloaded_unification): Fix DR 115 handling.
+
 2011-06-23  Paolo Carlini  <paolo.carlini@oracle.com>
 
        PR c++/44625

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 08ce5af..b3dd85f 100644 (file)
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -14524,6 +14524,7 @@ resolve_overloaded_unification (tree tparms,
         the affected templates before we try to unify, in case the
         explicit args will completely resolve the templates in question.  */
 
+      int ok = 0;
       tree expl_subargs = TREE_OPERAND (arg, 1);
       arg = TREE_OPERAND (arg, 0);
 
@@ -14538,7 +14539,7 @@ resolve_overloaded_unification (tree tparms,
          ++processing_template_decl;
          subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
                                  expl_subargs, /*check_ret=*/false);
-         if (subargs)
+         if (subargs && !any_dependent_template_arguments_p (subargs))
            {
              elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
              if (try_one_overload (tparms, targs, tempargs, parm,
@@ -14549,8 +14550,16 @@ resolve_overloaded_unification (tree tparms,
                  ++good;
                }
            }
+         else if (subargs)
+           ++ok;
          --processing_template_decl;
        }
+      /* If no templates (or more than one) are fully resolved by the
+        explicit arguments, this template-id is a non-deduced context; it
+        could still be OK if we deduce all template arguments for the
+        enclosing call through other arguments.  */
+      if (good != 1)
+       good = ok;
     }
   else if (TREE_CODE (arg) != OVERLOAD
           && TREE_CODE (arg) != FUNCTION_DECL)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c3e0f0e..bab71b3 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2011-06-23  Jason Merrill  <jason@redhat.com>
+
+       PR c++/35255
+       * g++.dg/template/partial10.C: New.
+       * g++.dg/template/partial11.C: New.
+
 2011-06-23  Jeff Law <law@redhat.com>
 
        PR middle-end/48770

diff --git a/gcc/testsuite/g++.dg/template/partial10.C b/gcc/testsuite/g++.dg/template/partial10.C
new file mode 100644 (file)
index 0000000..53a48fb
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/partial10.C
@@ -0,0 +1,18 @@
+// PR c++/35255, DR 115
+// { dg-do link }
+
+// 14.8.1: In contexts where deduction is done and fails, or in contexts
+// where deduction is not done, if a template argument list is specified
+// and it, along with any default template arguments, identifies a single
+// function template specialization, then the template-id is an lvalue for
+// the function template specialization.
+
+template <class Fn> void def(Fn fn) {}
+
+template <class T1, class T2> T2 fn(T1, T2);
+template <class T1> int fn(T1) { }
+
+int main()
+{
+  def(fn<int>);
+}

diff --git a/gcc/testsuite/g++.dg/template/partial11.C b/gcc/testsuite/g++.dg/template/partial11.C
new file mode 100644 (file)
index 0000000..b5ceaa8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/partial11.C
@@ -0,0 +1,24 @@
+// DR 115
+
+// 14.8.1: In contexts where deduction is done and fails, or in contexts
+// where deduction is not done, if a template argument list is specified
+// and it, along with any default template arguments, identifies a single
+// function template specialization, then the template-id is an lvalue for
+// the function template specialization.
+
+// Here, deduction is not done to resolve fn<int> because the target type
+// is a template parameter, so we resolve to the second template, and then
+// the call to def fails because we deduce different values of Fn for the
+// two function arguments.
+
+template <class Fn> void def(Fn fn, Fn fn2);
+
+template <class T1, class T2> T2 fn(T1, T2);
+template <class T1> int fn(T1);
+
+int f(int,int);
+
+int main()
+{
+  def(fn<int>,f);              // { dg-error "" }
+}