re PR c++/81258 (ICE on C++1z code with invalid decomposition declaration: in…

re PR c++/81258 (ICE on C++1z code with invalid decomposition declaration: in cp_finish_decl, at cp/decl.c:6760)

	PR c++/81258
	* parser.c (cp_parser_decomposition_declaration): Diagnose invalid
	forms of structured binding initializers.

	* g++.dg/cpp1z/decomp21.C (foo): Adjust expected diagnostics.
	* g++.dg/cpp1z/decomp30.C: New test.

From-SVN: r249947

gcc/cp/ChangeLog

+2017-07-04  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/81258
+	* parser.c (cp_parser_decomposition_declaration): Diagnose invalid
+	forms of structured binding initializers.
+
 2017-07-03  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/65775

gcc/cp/parser.c

@@ -13210,6 +13210,16 @@ cp_parser_decomposition_declaration (cp_parser *parser,
       *init_loc = cp_lexer_peek_token (parser->lexer)->location;
       tree initializer = cp_parser_initializer (parser, &is_direct_init,
 						&non_constant_p);
+      if (initializer == NULL_TREE
+	  || (TREE_CODE (initializer) == TREE_LIST
+	      && TREE_CHAIN (initializer))
+	  || (TREE_CODE (initializer) == CONSTRUCTOR
+	      && CONSTRUCTOR_NELTS (initializer) != 1))
+	{
+	  error_at (loc, "invalid initializer for structured binding "
+		    "declaration");
+	  initializer = error_mark_node;
+	}
 
       if (decl != error_mark_node)
 	{

gcc/testsuite/ChangeLog

+2017-07-04  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/81258
+	* g++.dg/cpp1z/decomp21.C (foo): Adjust expected diagnostics.
+	* g++.dg/cpp1z/decomp30.C: New test.
+
 2017-07-03  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/65775

gcc/testsuite/g++.dg/cpp1z/decomp21.C

@@ -12,5 +12,6 @@ foo ()
   auto [ n, o, p ] { a };
   auto [ q, r, t ] ( s );
   auto [ u, v, w ] ( s, );      // { dg-error "expected primary-expression before '.' token" }
-  auto [ x, y, z ] ( a );       // { dg-error "expression list treated as compound expression in initializer" "" { target *-*-* } .-1 }
+				// { dg-error "invalid initializer for structured binding declaration" "" { target *-*-* } .-1 }
+  auto [ x, y, z ] ( a );
 }

gcc/testsuite/g++.dg/cpp1z/decomp30.C

+// PR c++/81258
+// { dg-options -std=c++1z }
+
+int a[2];
+auto [b, c] (a);
+auto [d, e] { a };
+auto [f, g] = a;
+auto [h, i] ( a, a );	// { dg-error "invalid initializer for structured binding declaration" }
+auto [j, k] { a, a };	// { dg-error "invalid initializer for structured binding declaration" }
+auto [l, m] = { a };	// { dg-error "deducing from brace-enclosed initializer list requires" }
+auto [n, o] {};		// { dg-error "invalid initializer for structured binding declaration" }
+auto [p, q] ();		// { dg-error "invalid initializer for structured binding declaration" }