PR c++/89686 - mixing init-capture and simple-capture in lambda.

	* parser.c (cp_parser_lambda_introducer): Give error when combining
	init-capture and simple-capture.

	* g++.dg/cpp2a/lambda-pack-init2.C: New test.

From-SVN: r269659

gcc/cp/ChangeLog

@@ -8,6 +8,10 @@
 	(cp_parser_constructor_declarator_p): Add FLAGS parameter.  Pass it to
 	cp_parser_type_specifier.
 
+	PR c++/89686 - mixing init-capture and simple-capture in lambda.
+	* parser.c (cp_parser_lambda_introducer): Give error when combining
+	init-capture and simple-capture.
+
 2019-03-11  Jason Merrill  <jason@redhat.com>
 
 	PR c++/86521 - wrong overload resolution with ref-qualifiers.

gcc/cp/parser.c

@@ -10609,12 +10609,13 @@ cp_parser_lambda_introducer (cp_parser* parser, tree lambda_expr)
 	}
 
       bool init_pack_expansion = false;
+      location_t ellipsis_loc = UNKNOWN_LOCATION;
       if (cp_lexer_next_token_is (parser->lexer, CPP_ELLIPSIS))
 	{
-	  location_t loc = cp_lexer_peek_token (parser->lexer)->location;
+	  ellipsis_loc = cp_lexer_peek_token (parser->lexer)->location;
 	  if (cxx_dialect < cxx2a)
-	    pedwarn (loc, 0, "pack init-capture only available with "
-			     "%<-std=c++2a%> or %<-std=gnu++2a%>");
+	    pedwarn (ellipsis_loc, 0, "pack init-capture only available with "
+		     "%<-std=c++2a%> or %<-std=gnu++2a%>");
 	  cp_lexer_consume_token (parser->lexer);
 	  init_pack_expansion = true;
 	}
@@ -10719,8 +10720,21 @@ cp_parser_lambda_introducer (cp_parser* parser, tree lambda_expr)
 
 	  if (cp_lexer_next_token_is (parser->lexer, CPP_ELLIPSIS))
 	    {
+	      location_t loc = cp_lexer_peek_token (parser->lexer)->location;
 	      cp_lexer_consume_token (parser->lexer);
 	      capture_init_expr = make_pack_expansion (capture_init_expr);
+	      if (init_pack_expansion)
+		{
+		  /* If what follows is an initializer, the second '...' is
+		     invalid.  But for cases like [...xs...], the first one
+		     is invalid.  */
+		  if (cp_lexer_next_token_is (parser->lexer, CPP_EQ)
+		      || cp_lexer_next_token_is (parser->lexer, CPP_OPEN_PAREN)
+		      || cp_lexer_next_token_is (parser->lexer, CPP_OPEN_BRACE))
+		    ellipsis_loc = loc;
+		  error_at (ellipsis_loc, "too many %<...%> in lambda capture");
+		  continue;
+		}
 	    }
 	}
 

gcc/testsuite/ChangeLog

+2019-03-13  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/89686 - mixing init-capture and simple-capture in lambda.
+	* g++.dg/cpp2a/lambda-pack-init2.C: New test.
+
 2019-03-13  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/89601

gcc/testsuite/g++.dg/cpp2a/lambda-pack-init2.C

+// PR c++/89686
+// { dg-do compile { target c++2a } }
+
+template <typename... Ts>
+void foo(Ts... xs)
+{
+  int i = 10;
+  [...xs...]{}(); // { dg-error "4:too many ..... in lambda capture" }
+  [...xs...=xs]{}(); // { dg-error "9:too many ..... in lambda capture|expected" }
+  [xs...]{}();
+  [...xs=xs]{}();
+
+  [i, ...xs...]{}(); // { dg-error "7:too many ..... in lambda capture" }
+  [i, ...xs...=xs]{}(); // { dg-error "12:too many ..... in lambda capture|expected" }
+  [i, xs...]{}();
+  [i, ...xs=xs]{}();
+}
+
+int main()
+{
+ foo(0, 1, 2);
+}