[Diagnostics] Expand trailing closure failure to handle all closure arguments

Author: xedin

include/swift/AST/DiagnosticsSema.def

@@ -1550,9 +1550,9 @@ ERROR(extra_argument_to_nullary_call,none,
 ERROR(extra_trailing_closure_in_call,none,
       "extra trailing closure passed in "
       "%select{call|subscript|macro expansion}0", (unsigned))
-ERROR(trailing_closure_bad_param,none,
-      "trailing closure passed to parameter of type %0 that does not "
-      "accept a closure", (Type))
+ERROR(closure_bad_param,none,
+      "%select{|trailing }1closure passed to parameter of type %0 that does not "
+      "accept a closure", (Type, bool))
 WARNING(unlabeled_trailing_closure_deprecated,Deprecation,
         "backward matching of the unlabeled trailing closure is deprecated; label the argument with %0 to suppress this warning",
         (Identifier))

lib/Sema/CSDiagnostics.cpp

@@ -7292,7 +7292,7 @@ bool ArgumentMismatchFailure::diagnoseAsError() {
   if (diagnoseAttemptedRegexBuilder())
     return true;
 
-  if (diagnoseTrailingClosureMismatch())
+  if (diagnoseClosureMismatch())
     return true;
 
   if (diagnoseKeyPathAsFunctionResultMismatch())
@@ -7638,15 +7638,16 @@ bool ArgumentMismatchFailure::diagnoseAttemptedRegexBuilder() const {
   return true;
 }
 
-bool ArgumentMismatchFailure::diagnoseTrailingClosureMismatch() const {
-  if (!Info.isTrailingClosure())
+bool ArgumentMismatchFailure::diagnoseClosureMismatch() const {
+  if (!isExpr<ClosureExpr>(getAnchor()))
     return false;
 
   auto paramType = getToType();
   if (paramType->lookThroughAllOptionalTypes()->is<AnyFunctionType>())
     return false;
 
-  emitDiagnostic(diag::trailing_closure_bad_param, paramType)
+  emitDiagnostic(diag::closure_bad_param, paramType,
+                 Info.isTrailingClosure())
       .highlight(getSourceRange());
 
   if (auto overload = getCalleeOverloadChoiceIfAvailable(getLocator())) {

lib/Sema/CSDiagnostics.h

@@ -2118,9 +2118,9 @@ class ArgumentMismatchFailure : public ContextualFailure {
   /// or now deprecated `init(initialValue:)`.
   bool diagnosePropertyWrapperMismatch() const;
 
-  /// Tailored diagnostics for argument mismatches associated with trailing
+  /// Tailored diagnostics for argument mismatches associated with (trailing)
   /// closures being passed to non-closure parameters.
-  bool diagnoseTrailingClosureMismatch() const;
+  bool diagnoseClosureMismatch() const;
 
   /// Tailored key path as function diagnostics for argument mismatches where
   /// argument is a keypath expression that has a root type that matches a

test/Constraints/closures.swift

@@ -1153,7 +1153,7 @@ struct R_76250381<Result, Failure: Error> {
 func rdar77022842(argA: Bool? = nil, argB: Bool? = nil) {
   if let a = argA ?? false, if let b = argB ?? {
     // expected-error@-1 {{initializer for conditional binding must have Optional type, not 'Bool'}}
-    // expected-error@-2 {{cannot convert value of type '() -> ()' to expected argument type 'Bool?'}}
+    // expected-error@-2 {{closure passed to parameter of type 'Bool?' that does not accept a closure}}
     // expected-error@-3 {{cannot convert value of type 'Void' to expected condition type 'Bool'}}
   } // expected-error {{expected '{' after 'if' condition}}
 }

test/Sema/property_wrapper_parameter_invalid.swift

@@ -262,12 +262,12 @@ struct ProjectionWrapper<Value> {
 
 func testInvalidWrapperInference() {
   struct S<V> {
-    static func test(_ keyPath: KeyPath<V, String>) {} // expected-note {{'test' declared here}}
+    static func test(_ keyPath: KeyPath<V, String>) {} // expected-note 2 {{'test' declared here}}
   }
 
   // expected-error@+1 {{trailing closure passed to parameter of type 'KeyPath<Int, String>' that does not accept a closure}}
   S<Int>.test { $value in }
-  // expected-error@+1 {{cannot convert value of type '(_) -> ()' to expected argument type 'KeyPath<Int, String>'}}
+  // expected-error@+1 {{closure passed to parameter of type 'KeyPath<Int, String>' that does not accept a closure}}
   S<Int>.test({ $value in })
 
   func testGenericClosure<T>(_ closure: T) {}

test/expr/closure/closures.swift

@@ -42,9 +42,9 @@ func funcdecl5(_ a: Int, _ y: Int) {
   func6({($0) + $0})    // // expected-error {{contextual closure type '(Int, Int) -> Int' expects 2 arguments, but 1 was used in closure body}}
 
 
-  var testfunc : ((), Int) -> Int  // expected-note {{'testfunc' declared here}}
+  var testfunc : ((), Int) -> Int  // expected-note 2 {{'testfunc' declared here}}
   testfunc({$0+1})  // expected-error {{missing argument for parameter #2 in call}}
-  // expected-error@-1 {{cannot convert value of type '(Int) -> Int' to expected argument type '()'}}
+  // expected-error@-1 {{closure passed to parameter of type '()' that does not accept a closure}}
 
   funcdecl5(1, 2) // recursion.