From: Jason Merrill <jason@redhat.com>
Date: Thu, 15 Feb 2018 18:15:32 +0000 (-0500)
Subject: PR c++/84368 - wrong error with local variable in variadic lambda.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=4912defbcc3cc0d3a3af9673e413d45731c94da2;p=gcc.git

PR c++/84368 - wrong error with local variable in variadic lambda.

	* pt.c (tsubst_pack_expansion): Fix handling of non-packs in
	local_specializations.

From-SVN: r257699
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index f7fd4e36278..5ecc8ab2672 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2018-02-15  Jason Merrill  <jason@redhat.com>
+
+	PR c++/84368 - wrong error with local variable in variadic lambda.
+	* pt.c (tsubst_pack_expansion): Fix handling of non-packs in
+	local_specializations.
+
 2018-02-15  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/84330
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 3ac7adba00c..cd1aed8d677 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -11521,8 +11521,9 @@ tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
 	     context.  */
 	  tree gen = TREE_PURPOSE (elt);
 	  tree inst = TREE_VALUE (elt);
-	  if (DECL_PACK_P (inst))
-	    inst = retrieve_local_specialization (inst);
+	  if (DECL_P (inst))
+	    if (tree local = retrieve_local_specialization (inst))
+	      inst = local;
 	  /* else inst is already a full instantiation of the pack.  */
 	  register_local_specialization (inst, gen);
 	}
diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic14.C b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic14.C
new file mode 100644
index 00000000000..76567966293
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic14.C
@@ -0,0 +1,17 @@
+// PR c++/84368
+// { dg-do compile { target c++14 } }
+
+template < typename ... T >
+void sink(T ...){}
+
+template < typename ... T >
+void foo(T ... v){
+    [](auto ... v){
+        auto bar = [](auto, auto){ return 0; };
+        sink(bar(v, T{}) ...);
+    }(v ...);
+}
+
+int main(){
+    foo(0);
+}