[ConstraintSystem] Don't produce partially matching note if none of the overloads matched

Author: xedin

lib/Sema/ConstraintSystem.cpp

@@ -4338,9 +4338,28 @@ static void diagnoseOperatorAmbiguity(ConstraintSystem &cs,
     if (overloadType->hasTypeVariable())
       continue;
 
-    if (auto *fnType = overloadType->getAs<FunctionType>())
-      parameters.insert(
-          FunctionType::getParamListAsString(fnType->getParams()));
+    auto overloadFnTy = overloadType->getAs<FunctionType>();
+    if (!overloadFnTy)
+      continue;
+
+    // If arguments to all parameters have been fixed then there is nothing
+    // to note about in this overload.
+    std::set<unsigned> fixedParams;
+    llvm::for_each(solution.Fixes, [&](const ConstraintFix *fix) {
+      auto *locator = fix->getLocator();
+      if (getAsExpr(locator->getAnchor()) != applyExpr)
+        return;
+
+      if (auto argLoc = locator->findLast<LocatorPathElt::ApplyArgToParam>()) {
+        fixedParams.insert(argLoc->getParamIdx());
+      }
+    });
+
+    if (fixedParams.size() == overloadFnTy->getNumParams())
+      continue;
+
+    parameters.insert(
+        FunctionType::getParamListAsString(overloadFnTy->getParams()));
   }
 
   // All of the overload choices had generic parameters like `Self`.

test/Constraints/bridging.swift

@@ -275,7 +275,6 @@ func rdar19831698() {
   var v71 = true + 1.0 // expected-error{{binary operator '+' cannot be applied to operands of type 'Bool' and 'Double'}}
 // expected-note@-1{{overloads for '+'}}
   var v72 = true + true // expected-error{{binary operator '+' cannot be applied to two 'Bool' operands}}
-  // expected-note@-1{{overloads for '+'}}
   var v73 = true + [] // expected-error@:13 {{cannot convert value of type 'Bool' to expected argument type 'Array<Bool>'}}
   var v75 = true + "str" // expected-error@:13 {{cannot convert value of type 'Bool' to expected argument type 'String'}}
 }

test/Constraints/fixes.swift

@@ -363,5 +363,4 @@ func testKeyPathSubscriptArgFixes(_ fn: @escaping () -> Int) {
 // https://github.com/apple/swift/issues/54865
 func f_54865(a: Any, _ str: String?) {
   a == str // expected-error {{binary operator '==' cannot be applied to operands of type 'Any' and 'String?'}}
-  // expected-note@-1 {{overloads for '==' exist with these partially matching parameter lists: (String, String)}}
 }

test/Constraints/generics.swift

@@ -1017,6 +1017,7 @@ func test_requirement_failures_in_ambiguous_context() {
   func f1<T: Equatable>(_: T, _: T) {} // expected-note {{where 'T' = 'A'}}
 
   f1(A(), B()) // expected-error {{local function 'f1' requires that 'A' conform to 'Equatable'}}
+  // expected-error@-1 {{cannot convert value of type 'B' to expected argument type 'A'}}
 
   func f2<T: P_56173, U: P_56173>(_: T, _: U) {}
   // expected-note@-1 {{candidate requires that 'B' conform to 'P_56173' (requirement specified as 'U' : 'P_56173')}}

test/Constraints/operator.swift

@@ -219,7 +219,9 @@ func rdar46459603() {
   var arr = ["key": e]
 
   _ = arr.values == [e]
-  // expected-error@-1 {{binary operator '==' cannot be applied to operands of type 'Dictionary<String, E>.Values' and '[E]'}}
+  // expected-error@-1 {{referencing operator function '==' on 'Equatable' requires that 'Dictionary<String, E>.Values' conform to 'Equatable'}}
+  // expected-error@-2 {{cannot convert value of type '[E]' to expected argument type 'Dictionary<String, E>.Values'}}
+
   _ = [arr.values] == [[e]]
   // expected-error@-1 {{referencing operator function '==' on 'Array' requires that 'E' conform to 'Equatable'}} expected-note@-1 {{binary operator '==' cannot be synthesized for enums with associated values}}
   // expected-error@-2 {{cannot convert value of type 'Dictionary<String, E>.Values' to expected element type '[E]'}}

test/Constraints/optional.swift

@@ -436,7 +436,6 @@ func test_force_unwrap_not_being_too_eager() {
 func invalidOptionalChaining(a: Any) {
   a == "="? // expected-error {{cannot use optional chaining on non-optional value of type 'String'}}
   // expected-error@-1 {{binary operator '==' cannot be applied to operands of type 'Any' and 'String?'}}
-  // expected-note@-2 {{overloads for '==' exist}}
 }
 
 /// https://github.com/apple/swift/issues/54739

test/StringProcessing/Parse/forward-slash-regex.swift

@@ -131,7 +131,6 @@ _ = /x/.../y/
 
 _ = /x/...
 // expected-error@-1 {{unary operator '...' cannot be applied to an operand of type 'Regex<Substring>'}}
-// expected-note@-2 {{overloads for '...' exist with these partially matching parameter lists}}
 
 do {
   _ = /x /...

test/stdlib/UnicodeScalarDiagnostics.swift

@@ -10,11 +10,8 @@ func test_UnicodeScalarDoesNotImplementArithmetic(_ us: UnicodeScalar, i: Int) {
   isString(&a1)
   // We don't check for the overload choices list on the overload note match because they may change on different platforms. 
   let a2 = "a" - "b" // expected-error {{binary operator '-' cannot be applied to two 'String' operands}}
-  // expected-note@-1 {{overloads for '-' exist with these partially matching parameter lists:}}
   let a3 = "a" * "b" // expected-error {{binary operator '*' cannot be applied to two 'String' operands}}
-  // expected-note@-1 {{overloads for '*' exist with these partially matching parameter lists:}}
   let a4 = "a" / "b" // expected-error {{binary operator '/' cannot be applied to two 'String' operands}}
-  // expected-note@-1 {{overloads for '/' exist with these partially matching parameter lists:}}
 
   let b1 = us + us // expected-error {{binary operator '+' cannot be applied to two 'UnicodeScalar' (aka 'Unicode.Scalar') operands}}
   let b2 = us - us // expected-error {{binary operator '-' cannot be applied to two 'UnicodeScalar' (aka 'Unicode.Scalar') operands}}