Merge pull request #37658 from xedin/rdar-78224323

[Diagnostics] Augment "expected parameter" note with an argument type

Author: xedin

include/swift/AST/DiagnosticsSema.def

@@ -361,8 +361,8 @@ ERROR(cannot_convert_argument_value,none,
       (Type,Type))
 
 NOTE(candidate_has_invalid_argument_at_position,none,
-     "candidate expects %select{|in-out }2value of type %0 for parameter #%1",
-     (Type, unsigned, bool))
+     "candidate expects %select{|in-out }2value of type %0 for parameter #%1 (got %3)",
+     (Type, unsigned, bool, Type))
 
 ERROR(cannot_convert_array_to_variadic,none,
       "cannot pass array of type %0 as variadic arguments of type %1",

lib/Sema/CSDiagnostics.cpp

@@ -6135,10 +6135,10 @@ bool ArgumentMismatchFailure::diagnoseAsError() {
 bool ArgumentMismatchFailure::diagnoseAsNote() {
   auto *locator = getLocator();
   if (auto *callee = getCallee()) {
-    emitDiagnosticAt(
-        callee, diag::candidate_has_invalid_argument_at_position, getToType(),
-        getParamPosition(),
-        locator->isLastElement<LocatorPathElt::LValueConversion>());
+    emitDiagnosticAt(callee, diag::candidate_has_invalid_argument_at_position,
+                     getToType(), getParamPosition(),
+                     locator->isLastElement<LocatorPathElt::LValueConversion>(),
+                     getFromType());
     return true;
   }
 
@@ -7034,9 +7034,9 @@ bool AbstractRawRepresentableFailure::diagnoseAsNote() {
     }
   } else if (auto argConv =
                  locator->getLastElementAs<LocatorPathElt::ApplyArgToParam>()) {
-    diagnostic.emplace(
-        emitDiagnostic(diag::candidate_has_invalid_argument_at_position,
-                       RawReprType, argConv->getParamIdx(), /*inOut=*/false));
+    diagnostic.emplace(emitDiagnostic(
+        diag::candidate_has_invalid_argument_at_position, RawReprType,
+        argConv->getParamIdx(), /*inOut=*/false, ExpectedType));
   }
 
   if (diagnostic) {

lib/Sema/ConstraintSystem.cpp

@@ -3676,10 +3676,16 @@ static bool diagnoseAmbiguity(
         assert(fn);
 
         if (fn->getNumParams() == 1) {
+          auto argExpr =
+              simplifyLocatorToAnchor(solution.Fixes.front()->getLocator());
+          assert(argExpr);
+
           const auto &param = fn->getParams()[0];
+          auto argType = solution.simplifyType(cs.getType(argExpr));
+
           DE.diagnose(noteLoc, diag::candidate_has_invalid_argument_at_position,
                       solution.simplifyType(param.getPlainType()),
-                      /*position=*/1, param.isInOut());
+                      /*position=*/1, param.isInOut(), argType);
         } else {
           DE.diagnose(noteLoc, diag::candidate_partial_match,
                       fn->getParamListAsString(fn->getParams()));

test/Constraints/closures.swift

@@ -349,8 +349,8 @@ takeVoidVoidFn { () -> Void in
 }
 
 // <rdar://problem/19997471> Swift: Incorrect compile error when calling a function inside a closure
-func f19997471(_ x: String) {} // expected-note {{candidate expects value of type 'String' for parameter #1}}
-func f19997471(_ x: Int) {}    // expected-note {{candidate expects value of type 'Int' for parameter #1}}
+func f19997471(_ x: String) {} // expected-note {{candidate expects value of type 'String' for parameter #1 (got 'T')}}
+func f19997471(_ x: Int) {}    // expected-note {{candidate expects value of type 'Int' for parameter #1 (got 'T')}}
 
 func someGeneric19997471<T>(_ x: T) {
   takeVoidVoidFn {

test/Constraints/construction.swift

@@ -16,9 +16,9 @@ enum Z {
 
   init() { self = .none }
   init(_ c: UnicodeScalar) { self = .char(c) }
-  // expected-note@-1 2 {{candidate expects value of type 'UnicodeScalar' (aka 'Unicode.Scalar') for parameter #1}}
+  // expected-note@-1 2 {{candidate expects value of type 'UnicodeScalar' (aka 'Unicode.Scalar') for parameter #1 (got 'Z')}}
   init(_ s: String) { self = .string(s) }
-  // expected-note@-1 2 {{candidate expects value of type 'String' for parameter #1}}
+  // expected-note@-1 2 {{candidate expects value of type 'String' for parameter #1 (got 'Z')}}
   init(_ x: Int, _ y: Int) { self = .point(x, y) }
 }
 

test/Constraints/diagnostics.swift

@@ -399,9 +399,9 @@ enum Color {
   static func rainbow() -> Color {}
 
   static func overload(a : Int) -> Color {} // expected-note {{incorrect labels for candidate (have: '(_:)', expected: '(a:)')}}
-  // expected-note@-1 {{candidate expects value of type 'Int' for parameter #1}}
+  // expected-note@-1 {{candidate expects value of type 'Int' for parameter #1 (got 'Double')}}
   static func overload(b : Int) -> Color {} // expected-note {{incorrect labels for candidate (have: '(_:)', expected: '(b:)')}}
-  // expected-note@-1 {{candidate expects value of type 'Int' for parameter #1}}
+  // expected-note@-1 {{candidate expects value of type 'Int' for parameter #1 (got 'Double')}}
 
   static func frob(_ a : Int, b : inout Int) -> Color {}
   static var svar: Color { return .Red }

test/Constraints/overload.swift

@@ -3,9 +3,9 @@
 func markUsed<T>(_ t: T) {}
 
 func f0(_: Float) -> Float {}
-// expected-note@-1 {{candidate expects value of type 'Float' for parameter #1}}
+// expected-note@-1 {{candidate expects value of type 'Float' for parameter #1 (got 'X')}}
 func f0(_: Int) -> Int {}
-// expected-note@-1 {{candidate expects value of type 'Int' for parameter #1}}
+// expected-note@-1 {{candidate expects value of type 'Int' for parameter #1 (got 'X')}}
 
 func f1(_: Int) {}
 

test/Sema/diag_ambiguous_overloads.swift

@@ -147,8 +147,8 @@ array.withUnsafeBufferPointer {
   // expected-note@-5 {{found candidate with type '(UnsafeMutableRawPointer) -> UnsafeRawPointer'}}
 }
 
-func SR12689_1(_ u: Int) -> String { "" } // expected-note {{found this candidate}} expected-note {{candidate expects value of type 'Int' for parameter #1}}
-func SR12689_1(_ u: String) -> Double { 0 } // expected-note {{found this candidate}} expected-note {{candidate expects value of type 'String' for parameter #1}}
+func SR12689_1(_ u: Int) -> String { "" } // expected-note {{found this candidate}} expected-note {{candidate expects value of type 'Int' for parameter #1 (got 'Double')}}
+func SR12689_1(_ u: String) -> Double { 0 } // expected-note {{found this candidate}} expected-note {{candidate expects value of type 'String' for parameter #1 (got 'Double')}}
 func SR12689_2(_ u: Int) {}
 
 SR12689_2(SR12689_1(1 as Double)) // expected-error {{no exact matches in call to global function 'SR12689_1'}}