Merge pull request #29735 from owenv/multiple-varargs

[SE-0284] Allow Multiple Variadic Parameters in Functions, Subscripts, and Initializers

include/swift/AST/DiagnosticsParse.def

@@ -882,8 +882,6 @@ ERROR(expected_parameter_colon,PointsToFirstBadToken,
       "expected ':' following argument label and parameter name", ())
 ERROR(expected_assignment_instead_of_comparison_operator,none,
       "expected '=' instead of '==' to assign default value for parameter", ())
-ERROR(multiple_parameter_ellipsis,none,
-      "only a single variadic parameter '...' is permitted", ())
 ERROR(parameter_vararg_default,none,
       "variadic parameter cannot have a default value", ())
 ERROR(parameter_specifier_as_attr_disallowed,none,
@@ -916,6 +914,8 @@ ERROR(initializer_as_typed_pattern,none,
 
 ERROR(unlabeled_parameter_following_variadic_parameter,none,
       "a parameter following a variadic parameter requires a label", ())
+ERROR(closure_unlabeled_parameter_following_variadic_parameter,none,
+      "no parameters may follow a variadic parameter in a closure", ())
 
 ERROR(enum_element_empty_arglist,none,
       "enum element with associated values must have at least one "

lib/Parse/ParsePattern.cpp

@@ -574,7 +574,6 @@ mapParsedParameters(Parser &parser,
   // Collect the elements of the tuple patterns for argument and body
   // parameters.
   SmallVector<ParamDecl*, 4> elements;
-  SourceLoc ellipsisLoc;
 
   for (auto &param : params) {
     // Whether the provided name is API by default depends on the parameter
@@ -625,27 +624,26 @@ mapParsedParameters(Parser &parser,
     }
 
     // Warn when an unlabeled parameter follows a variadic parameter
-    if (ellipsisLoc.isValid() && elements.back()->isVariadic() &&
-        param.FirstName.empty()) {
-      parser.diagnose(param.FirstNameLoc,
-                      diag::unlabeled_parameter_following_variadic_parameter);
+    if (!elements.empty() && elements.back()->isVariadic() && argName.empty()) {
+      // Closure parameters can't have external labels, so use a more specific
+      // diagnostic.
+      if (paramContext == Parser::ParameterContextKind::Closure)
+        parser.diagnose(
+            param.FirstNameLoc,
+            diag::closure_unlabeled_parameter_following_variadic_parameter);
+      else
+        parser.diagnose(param.FirstNameLoc,
+                        diag::unlabeled_parameter_following_variadic_parameter);
     }
-
-    // If this parameter had an ellipsis, check whether it's the last parameter.
-    if (param.EllipsisLoc.isValid()) {
-      if (ellipsisLoc.isValid()) {
-        parser.diagnose(param.EllipsisLoc, diag::multiple_parameter_ellipsis)
-          .highlight(ellipsisLoc)
-          .fixItRemove(param.EllipsisLoc);
 
-        param.EllipsisLoc = SourceLoc();
-      } else if (!result->getTypeRepr()) {
+    // If this parameter had an ellipsis, check it has a TypeRepr.
+    if (param.EllipsisLoc.isValid()) {
+      if (!result->getTypeRepr()) {
         parser.diagnose(param.EllipsisLoc, diag::untyped_pattern_ellipsis)
           .highlight(result->getSourceRange());
 
         param.EllipsisLoc = SourceLoc();
       } else {
-        ellipsisLoc = param.EllipsisLoc;
         result->setVariadic();
       }
     }

test/Constraints/argument_matching.swift

@@ -305,6 +305,93 @@ variadics6(x: 1, 2, 3) // expected-error{{missing argument for parameter 'z' in
 variadics6(x: 1) // expected-error{{missing argument for parameter 'z' in call}}
 variadics6() // expected-error{{missing argument for parameter 'z' in call}}
 
+func variadics7(_ x: Int..., y: Int...) { }
+
+// Using multiple variadics (in order, complete)
+variadics7(1, y: 2)
+variadics7(1, 2, 3, y: 4, 5, 6)
+variadics7(1, 2, y: 2)
+variadics7(1, y: 2, 1)
+
+// multiple variadics, in order, some missing
+variadics7(y: 1)
+variadics7(1)
+variadics7(y: 4, 5, 6)
+variadics7(1, 2, 3)
+
+func variadics8(x: Int..., y: Int...) { }
+
+// multiple variadics, out of order
+variadics8(y: 1, x: 2) // expected-error {{argument 'x' must precede argument 'y'}} {{12-12=x: 2, }} {{16-22=}}
+variadics8(y: 1, 2, 3, x: 4) // expected-error {{argument 'x' must precede argument 'y'}} {{12-12=x: 4, }} {{22-28=}}
+variadics8(y: 1, x: 2, 3, 4) // expected-error {{argument 'x' must precede argument 'y'}} {{12-12=x: 2, 3, 4, }} {{16-28=}}
+variadics8(y: 1, 2, 3, x: 4, 5, 6) // expected-error {{argument 'x' must precede argument 'y'}} {{12-12=x: 4, 5, 6, }} {{22-34=}}
+
+func variadics9(_ a: Int..., b: Int, _ c: Int...) { } // expected-note {{'variadics9(_:b:_:)' declared here}}
+
+// multiple split variadics, in order, complete
+variadics9(1, b: 2, 3)
+variadics9(1, 2, 3, b: 2, 3)
+variadics9(1, b: 2, 3, 2, 1)
+variadics9(1, 2, 3, b: 2, 3, 2, 1)
+
+// multiple split variadics, in order, some missing
+variadics9(b: 2, 3)
+variadics9(1, b: 2)
+variadics9(1, 2, b: 2)
+variadics9(b: 2, 3, 2, 1)
+
+// multiple split variadics, required missing
+variadics9(1) // expected-error {{missing argument for parameter 'b' in call}}
+
+func variadics10(_ a: Int..., b: Int = 2, _ c: Int...) { }
+
+// multiple unlabeled variadics split by defaulted param, in order, complete
+variadics10(1, b: 2, 3)
+variadics10(1, 2, 3, b: 2, 3)
+variadics10(1, b: 2, 3, 2, 1)
+variadics10(1, 2, 3, b: 2, 3, 2, 1)
+
+// multiple unlabeled variadics split by defaulted param, in order, some missing
+variadics10(1, 2, 3)
+variadics10(1, 2, 3, b: 3)
+variadics10(b: 3)
+
+func variadics11(_ a: Int..., b: Bool = false, _ c: String...) { }
+
+variadics11(1, 2, 3, b: true, "hello", "world")
+variadics11(b: true, "hello", "world")
+variadics11(1, 2, 3, b: true)
+variadics11(b: true)
+variadics11()
+variadics11(1, 2, 3, "hello", "world") // expected-error 2 {{cannot convert value of type 'String' to expected argument type 'Int'}}
+
+func variadics12(a: Int..., b: Int, c: Int...) { }
+
+variadics12(a: 1, 2, 3, b: 4, c: 5, 6, 7)
+variadics12(b: 4, c: 5, 6, 7)
+variadics12(a: 1, 2, 3, b: 4)
+
+variadics12(c: 5, 6, 7, b: 4, a: 1, 2, 3) // expected-error {{incorrect argument labels in call (have 'c:_:_:b:a:_:_:', expected 'a:b:c:')}} {{13-14=a}} {{19-19=b: }} {{22-22=c: }} {{25-28=}} {{31-34=}}
+
+
+// Edge cases involving multiple trailing closures and forward matching.
+func variadics13(a: Int..., b: (()->Void)...) {}
+
+variadics13()
+variadics13(a: 1, 2, 3) {} _: {} _: {}
+variadics13() {} _: {} _: {}
+variadics13(a: 1, 2, 3)
+variadics13(a: 1, 2, 3) {}
+
+func variadics14(a: (()->Void)..., b: (()->Void)...) {} // expected-note {{'variadics14(a:b:)' declared here}}
+
+variadics14(a: {}, {}, b: {}, {})
+variadics14(a: {}, {}) {} _: {}
+variadics14 {} _: {} b: {} _: {}
+variadics14 {} b: {}
+variadics14 {} // expected-warning {{backward matching of the unlabeled trailing closure is deprecated; label the argument with 'b' to suppress this warning}}
+
 func outOfOrder(_ a : Int, b: Int) {
   outOfOrder(b: 42, 52)  // expected-error {{unnamed argument #2 must precede argument 'b'}} {{14-14=52, }} {{19-23=}}
 }
@@ -1336,6 +1423,26 @@ d = sub2[d] // expected-error{{missing argument label 'd:' in subscript}} {{10-1
 d = sub2[d: d]
 d = sub2[f: d] // expected-error{{incorrect argument label in subscript (have 'f:', expected 'd:')}} {{10-11=d}}
 
+struct Sub3 {
+  subscript (a: Int..., b b: Int...) -> Int { 42 }
+}
+
+let sub3 = Sub3()
+_ = sub3[1, 2, 3, b: 4, 5, 6]
+_ = sub3[b: 4, 5, 6]
+_ = sub3[1, 2, 3]
+_ = sub3[1, c: 4] // expected-error {{incorrect argument label in subscript (have '_:c:', expected '_:b:')}}
+
+struct Sub4 {
+  subscript (a: Int..., b b: Int = 0, c: Int...) -> Int { 42 }
+}
+
+let sub4 = Sub4()
+_ = sub4[1, 2, 3, b: 2, 1, 2, 3]
+_ = sub4[1, 2, 3, b: 2]
+_ = sub4[1, 2, 3]
+_ = sub4[]
+
 // -------------------------------------------
 // Closures
 // -------------------------------------------

test/Interpreter/multiple_varargs.swift

@@ -0,0 +1,85 @@
+// RUN: %target-run-simple-swift | %FileCheck %s
+
+// REQUIRES: executable_test
+
+func vf(x: Int..., y: Int...) {
+	print(x, y)
+}
+
+vf(x: 1, 2, 3, y: 4, 5, 6)
+// CHECK: [1, 2, 3] [4, 5, 6]
+vf(y: 1, 2)
+// CHECK: [] [1, 2]
+vf(x: 3, 4)
+// CHECK: [3, 4] []
+
+func vf2(_ x: Int..., y: Int, _ z: Int...) {
+  print(x, y, z)
+}
+
+vf2(1, 2, 3, y: 4, 5, 6, 7)
+// CHECK: [1, 2, 3] 4 [5, 6, 7]
+vf2(y: 4, 5, 6, 7)
+// CHECK: [] 4 [5, 6, 7]
+vf2(1, 2, 3, y: 4)
+// CHECK: [1, 2, 3] 4 []
+vf2(y: 4)
+// CHECK: [] 4 []
+
+func vf3(_ x: Int..., y: Int = 42, _ z: Int...) {
+  print(x, y, z)
+}
+
+vf3(1, 2, 3, y: 4, 5, 6, 7)
+// CHECK: [1, 2, 3] 4 [5, 6, 7]
+vf3(y: 4, 5, 6, 7)
+// CHECK: [] 4 [5, 6, 7]
+vf3(1, 2, 3, y: 4)
+// CHECK: [1, 2, 3] 4 []
+vf3(y: 4)
+// CHECK: [] 4 []
+
+vf3()
+// CHECK: [] 42 []
+vf3(1, 2, 3)
+// CHECK: [1, 2, 3] 42 []
+
+func foo(a: Int..., b: Int, c: Int..., d: Int) {
+  print("one")
+}
+
+func foo(a: [Int], b: Int, c: [Int], d: Int) {
+  print("two")
+}
+
+func foo(a: Int..., b: Int, c: [Int], d: Int) {
+  print("three")
+}
+
+foo(a: 1, 2, 3, b: 4, c: 5, 6, 7, d: 8)
+// CHECK: one
+foo(a: [1, 2, 3], b: 4, c: [5, 6, 7], d: 8)
+// CHECK: two
+foo(a: 1, 2, 3, b: 4, c: [5, 6, 7], d: 8)
+// CHECK: three
+
+struct Baz {
+  init(a: Int..., b: Int...) {
+    print(a, b)
+  }
+
+  init(_ a: Int..., b: String, _ c: Int...) {
+    print(a, b, c)
+  }
+
+  subscript(a: Int..., b b: Int...) -> [Int] { a + b }
+}
+
+let baz1 = Baz(a: 1, 2, 3, b: 4, 5, 6)
+// CHECK: [1, 2, 3] [4, 5, 6]
+
+let baz2 = Baz(1, 2, 3, b: "hello, world!", 3, 2, 1)
+// CHECK: [1, 2, 3] hello, world! [3, 2, 1]
+
+print(baz1[1, 2, b: 3, 4])
+// CHECK: [1, 2, 3, 4]

test/SILGen/arguments.swift

@@ -82,6 +82,14 @@ func variadic_arg_3(_ y: Float..., x: Int) {}
 // CHECK-LABEL: sil hidden [ossa] @$ss14variadic_arg_3{{[_0-9a-zA-Z]*}}F
 // CHECK: bb0([[Y:%[0-9]+]] : $Array<Float>, [[X:%[0-9]+]] : $Int):
 
+func variadic_arg_4(_ y: Float..., x: Int...) {}
+// CHECK-LABEL: sil hidden [ossa] @$ss14variadic_arg_4{{[_0-9a-zA-Z]*}}F
+// CHECK: bb0([[Y:%[0-9]+]] : $Array<Float>, [[X:%[0-9]+]] : $Array<Int>):
+
+func variadic_arg_5(a: Int, b: Float..., c: Int, d: Int...) {}
+// CHECK-LABEL: sil hidden [ossa] @$ss14variadic_arg_5{{[_0-9a-zA-Z]*}}F
+// CHECK: bb0([[A:%[0-9]+]] : $Int, [[B:%[0-9]+]] : $Array<Float>, [[C:%[0-9]+]] : $Int, [[D:%[0-9]+]] : $Array<Int>):
+
 variadic_arg_3(x: i)
 variadic_arg_3(f, x: i)
 variadic_arg_3(f, f, f, x: i)

test/Syntax/Outputs/round_trip_parse_gen.swift.withkinds

@@ -102,13 +102,15 @@ class C <MemberDeclBlock>{<MemberDeclListItem><FunctionDecl>
   @objc </Attribute><DeclModifier>private </DeclModifier>init<ParameterClause>(<FunctionParameter>a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>)</ParameterClause></InitializerDecl></MemberDeclListItem><MemberDeclListItem><InitializerDecl>
   init!<ParameterClause>(<FunctionParameter>a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause><CodeBlock>{}</CodeBlock></InitializerDecl></MemberDeclListItem><MemberDeclListItem><InitializerDecl>
   init?<ParameterClause>(<FunctionParameter>a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause><CodeBlock>{}</CodeBlock></InitializerDecl></MemberDeclListItem><MemberDeclListItem><InitializerDecl><DeclModifier>
-  public </DeclModifier>init<ParameterClause>(<FunctionParameter>a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause>throws <CodeBlock>{}</CodeBlock></InitializerDecl></MemberDeclListItem><MemberDeclListItem><DeinitializerDecl><Attribute>
+  public </DeclModifier>init<ParameterClause>(<FunctionParameter>a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause>throws <CodeBlock>{}</CodeBlock></InitializerDecl></MemberDeclListItem><MemberDeclListItem><InitializerDecl>
+  init<ParameterClause>(<FunctionParameter>a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier>..., </FunctionParameter><FunctionParameter>b: <SimpleTypeIdentifier>Double</SimpleTypeIdentifier>...</FunctionParameter>) </ParameterClause><CodeBlock>{}</CodeBlock></InitializerDecl></MemberDeclListItem><MemberDeclListItem><DeinitializerDecl><Attribute>
 
   @objc </Attribute>deinit <CodeBlock>{}</CodeBlock></DeinitializerDecl></MemberDeclListItem><MemberDeclListItem><DeinitializerDecl><DeclModifier>
   private </DeclModifier>deinit <CodeBlock>{}</CodeBlock></DeinitializerDecl></MemberDeclListItem><MemberDeclListItem><SubscriptDecl><DeclModifier>
 
   internal </DeclModifier>subscript<ParameterClause>(<FunctionParameter>x: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause><ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause><AccessorBlock>{ <AccessorDecl>get <CodeBlock>{} </CodeBlock></AccessorDecl><AccessorDecl>set <CodeBlock>{} </CodeBlock></AccessorDecl>}</AccessorBlock></SubscriptDecl></MemberDeclListItem><MemberDeclListItem><SubscriptDecl>
-  subscript<ParameterClause>() </ParameterClause><ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause><CodeBlock>{ <ReturnStmt>return <IntegerLiteralExpr>1 </IntegerLiteralExpr></ReturnStmt>}</CodeBlock></SubscriptDecl></MemberDeclListItem><MemberDeclListItem><VariableDecl>
+  subscript<ParameterClause>() </ParameterClause><ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause><CodeBlock>{ <ReturnStmt>return <IntegerLiteralExpr>1 </IntegerLiteralExpr></ReturnStmt>}</CodeBlock></SubscriptDecl></MemberDeclListItem><MemberDeclListItem><SubscriptDecl>
+  subscript<ParameterClause>(<FunctionParameter>x: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier>..., </FunctionParameter><FunctionParameter>y y: <SimpleTypeIdentifier>String</SimpleTypeIdentifier>...</FunctionParameter>) </ParameterClause><ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause><CodeBlock>{ <ReturnStmt>return <IntegerLiteralExpr>1 </IntegerLiteralExpr></ReturnStmt>}</CodeBlock></SubscriptDecl></MemberDeclListItem><MemberDeclListItem><VariableDecl>
 
   var <PatternBinding><IdentifierPattern>x</IdentifierPattern><TypeAnnotation>: <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></TypeAnnotation><CodeBlock>{<FunctionCallExpr><IdentifierExpr>
     address </IdentifierExpr><ClosureExpr>{ <FunctionCallExpr><IdentifierExpr>fatalError</IdentifierExpr>() </FunctionCallExpr>}</ClosureExpr></FunctionCallExpr><FunctionCallExpr><IdentifierExpr>
@@ -197,7 +199,8 @@ func foo<FunctionSignature><ParameterClause>(<FunctionParameter>_ _: <SimpleType
          d _: <SimpleTypeIdentifier>Int </SimpleTypeIdentifier><InitializerClause>= <SequenceExpr><TernaryExpr><BooleanLiteralExpr>true </BooleanLiteralExpr>? <IntegerLiteralExpr>2</IntegerLiteralExpr>: <IntegerLiteralExpr>3</IntegerLiteralExpr></TernaryExpr></SequenceExpr></InitializerClause>,</FunctionParameter><FunctionParameter><Attribute>
          @objc </Attribute>e: <SimpleTypeIdentifier>X </SimpleTypeIdentifier><InitializerClause>= <BooleanLiteralExpr>true</BooleanLiteralExpr></InitializerClause>,</FunctionParameter><FunctionParameter>
          f: <AttributedType>inout <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></AttributedType>,</FunctionParameter><FunctionParameter>
-         g: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier>...</FunctionParameter>) </ParameterClause>throws <ReturnClause>-> <DictionaryType>[<SimpleTypeIdentifier>Int</SimpleTypeIdentifier>: <SimpleTypeIdentifier>String</SimpleTypeIdentifier>] </DictionaryType></ReturnClause></FunctionSignature><CodeBlock>{}</CodeBlock></FunctionDecl><FunctionDecl>
+         g: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier>...,</FunctionParameter><FunctionParameter>
+         h: <SimpleTypeIdentifier>Bool</SimpleTypeIdentifier>...</FunctionParameter>) </ParameterClause>throws <ReturnClause>-> <DictionaryType>[<SimpleTypeIdentifier>Int</SimpleTypeIdentifier>: <SimpleTypeIdentifier>String</SimpleTypeIdentifier>] </DictionaryType></ReturnClause></FunctionSignature><CodeBlock>{}</CodeBlock></FunctionDecl><FunctionDecl>
 
 func foo<FunctionSignature><ParameterClause>(<FunctionParameter>_ a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause>throws <ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause></FunctionSignature><CodeBlock>{}</CodeBlock></FunctionDecl><FunctionDecl>
 func foo<FunctionSignature><ParameterClause>( <FunctionParameter>a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause>rethrows <ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause></FunctionSignature><CodeBlock>{}</CodeBlock></FunctionDecl><StructDecl>

test/Syntax/round_trip_parse_gen.swift

@@ -103,12 +103,14 @@ class C {
   init!(a: Int) {}
   init?(a: Int) {}
   public init(a: Int) throws {}
+  init(a: Int..., b: Double...) {}
 
   @objc deinit {}
   private deinit {}
 
   internal subscript(x: Int) -> Int { get {} set {} }
   subscript() -> Int { return 1 }
+  subscript(x: Int..., y y: String...) -> Int { return 1 }
 
   var x: Int {
     address { fatalError() }
@@ -197,7 +199,8 @@ func foo(_ _: Int,
          d _: Int = true ? 2: 3,
          @objc e: X = true,
          f: inout Int,
-         g: Int...) throws -> [Int: String] {}
+         g: Int...,
+         h: Bool...) throws -> [Int: String] {}
 
 func foo(_ a: Int) throws -> Int {}
 func foo( a: Int) rethrows -> Int {}

test/decl/func/vararg.swift

@@ -27,7 +27,38 @@ func invalidVariadic(_ e: NonExistentType) { // expected-error {{cannot find typ
   { (e: ExtraCrispy...) in }() // expected-error {{cannot find type 'ExtraCrispy' in scope}}
 }
 
-func twoVariadics(_ a: Int..., b: Int...) { } // expected-error{{only a single variadic parameter '...' is permitted}} {{38-41=}}
+func twoVariadics(_ a: Int..., b: Int...) { }
+func unlabeledFollowingVariadic(_ a: Int..., _ b: Int) { } // expected-error {{a parameter following a variadic parameter requires a label}}
+func unlabeledVariadicFollowingVariadic(_ a: Int..., _ b: Int...) { } // expected-error {{a parameter following a variadic parameter requires a label}}
+func unlabeledFollowingTwoVariadics(_ a: Int..., b: Int..., _ c: Int) { } // expected-error {{a parameter following a variadic parameter requires a label}}
+func splitVariadics(_ a: Int..., b: Int, _ c: String...) { }
+func splitByDefaultArgVariadics(_ a: Int..., b: Int = 0, _ c: String...) { }
+
+struct HasSubscripts {
+  subscript(a: Int...) -> Void { () }
+  subscript(a: Int..., b b: Int...) -> Void { () }
+  subscript(a: Int..., b: Int...) -> Void { () } // expected-error {{a parameter following a variadic parameter requires a label}}
+  subscript(a: Int..., b: Int) -> Void { () } // expected-error {{a parameter following a variadic parameter requires a label}}
+  subscript(a: Int..., b b: Int..., c c: Int) -> Void { () }
+  subscript(a: Int..., b b: Int..., c: Int) -> Void { () } // expected-error {{a parameter following a variadic parameter requires a label}}
+  subscript(a: Int..., c c: Int = 0, b: Int...) -> Void { () }
+  subscript(a: Int..., b: String = "hello, world!") -> Bool { false } // expected-error {{a parameter following a variadic parameter requires a label}}
+}
+
+struct HasInitializers {
+  init(a: Int...) {}
+  init(a: Int..., b: Int...) {}
+  init(a: Int..., _ b: Int...) {} // expected-error {{a parameter following a variadic parameter requires a label}}
+  init(a: Int..., c: Int = 0, _ b: Int...) {}
+}
+
+let closure = {(x: Int..., y: Int...) in } // expected-error {{no parameters may follow a variadic parameter in a closure}}
+let closure2 = {(x: Int..., y: Int) in } // expected-error {{no parameters may follow a variadic parameter in a closure}}
+let closure3 = {(x: Int..., y: Int, z: Int...) in } // expected-error {{no parameters may follow a variadic parameter in a closure}}
+let closure4 = {(x: Int...) in }
+let closure5 = {(x: Int, y: Int...) in }
+let closure6 = {(x: Int..., y z: Int) in } // expected-error {{closure cannot have keyword arguments}}
+// expected-error@-1 {{no parameters may follow a variadic parameter in a closure}}
 
 // rdar://22056861
 func f5(_ list: Any..., end: String = "") {}