PR c++/84420 - ICE with structured binding in lambda.

	* lambda.c (is_capture_proxy): Check DECL_DECOMPOSITION_P.

From-SVN: r257761

gcc/cp/ChangeLog

 2018-02-16  Jason Merrill  <jason@redhat.com>
 
+	PR c++/84420 - ICE with structured binding in lambda.
+	* lambda.c (is_capture_proxy): Check DECL_DECOMPOSITION_P.
+
 	PR c++/83835 - C++17 error with constructor ctors.
 	* call.c (build_special_member_call): Set TARGET_EXPR_DIRECT_INIT_P.
 

gcc/cp/lambda.c

@@ -261,6 +261,7 @@ is_capture_proxy (tree decl)
   return (VAR_P (decl)
 	  && DECL_HAS_VALUE_EXPR_P (decl)
 	  && !DECL_ANON_UNION_VAR_P (decl)
+	  && !DECL_DECOMPOSITION_P (decl)
 	  && LAMBDA_FUNCTION_P (DECL_CONTEXT (decl)));
 }
 

gcc/testsuite/g++.dg/cpp1z/decomp-lambda1.C

+// PR c++/84420
+// { dg-additional-options -std=c++17 }
+
+int main(){
+    int a[1]{};
+    [&a]{
+        auto [v] = a;
+        (void)v;
+    }();
+}