PR c++/82331 - ICE with variadic partial specialization of auto

	* pt.c (unify) [TEMPLATE_PARM_INDEX]: Set processing_template_decl
	around call to tsubst.

From-SVN: r255430

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index d5141f0..122045b 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2017-12-05  Jason Merrill  <jason@redhat.com>
+
+       PR c++/82331 - ICE with variadic partial specialization of auto
+       * pt.c (unify) [TEMPLATE_PARM_INDEX]: Set processing_template_decl
+       around call to tsubst.
+
 2017-12-05  Nathan Sidwell  <nathan@acm.org>
 
        PR c++/83287

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 500ac0c..685f34a 100644 (file)
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -20942,7 +20942,9 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict,
         template-parameter exactly, except that a template-argument
         deduced from an array bound may be of any integral type.
         The non-type parameter might use already deduced type parameters.  */
+      ++processing_template_decl;
       tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
+      --processing_template_decl;
       if (tree a = type_uses_auto (tparm))
        {
          tparm = do_auto_deduction (tparm, arg, a, complain, adc_unify);

diff --git a/gcc/testsuite/g++.dg/cpp1z/nontype-auto13.C b/gcc/testsuite/g++.dg/cpp1z/nontype-auto13.C
new file mode 100644 (file)
index 0000000..2152cef
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/nontype-auto13.C
@@ -0,0 +1,18 @@
+// PR c++/82331
+// { dg-options -std=c++17 }
+
+template <auto>
+class X;
+
+template <typename R, typename... A, R (*F) (A...)>
+class X<F> {
+public:
+    static R call (A... args)
+    {
+        return (*F)(args...);
+    }
+};
+
+int func (int a, int b) { return a + b; }
+
+int test () { return X<&func>::call(1, 2); }