swiftlang · xedin · Aug 19, 2019 · Aug 19, 2019
diff --git a/lib/Sema/CSDiagnostics.cpp b/lib/Sema/CSDiagnostics.cpp
@@ -650,10 +650,8 @@ void GenericArgumentsMismatchFailure::emitNoteForMismatch(int position) {
   auto genericTypeDecl = paramSourceTy->getAnyGeneric();
   auto param = genericTypeDecl->getGenericParams()->getParams()[position];
 
-  auto lhs = resolveType(getActual()->getGenericArgs()[position])
-                 ->reconstituteSugar(/*recursive=*/false);
-  auto rhs = resolveType(getRequired()->getGenericArgs()[position])
-                 ->reconstituteSugar(/*recursive=*/false);
+  auto lhs = getActual()->getGenericArgs()[position];
+  auto rhs = getRequired()->getGenericArgs()[position];
 
   auto noteLocation = param->getLoc();
 
@@ -677,8 +675,8 @@ bool GenericArgumentsMismatchFailure::diagnoseAsError() {
     const auto &last = path.back();
     switch (last.getKind()) {
     case ConstraintLocator::ContextualType: {
-      auto purpose = getConstraintSystem().getContextualTypePurpose();
-      assert(purpose != CTP_Unused);
+      auto purpose = getContextualTypePurpose();
+      assert(!(purpose == CTP_Unused && purpose == CTP_CannotFail));
       diagnostic = getDiagnosticFor(purpose);
       break;
     }
@@ -701,17 +699,14 @@ bool GenericArgumentsMismatchFailure::diagnoseAsError() {
     }
 
     default:
-      break;
+      return false;
     }
   }
 
   if (!diagnostic)
     return false;
 
-  emitDiagnostic(
-      getAnchor()->getLoc(), *diagnostic,
-      resolveType(getActual())->reconstituteSugar(/*recursive=*/false),
-      resolveType(getRequired())->reconstituteSugar(/*recursive=*/false));
+  emitDiagnostic(anchor->getLoc(), *diagnostic, getFromType(), getToType());
   emitNotesForMismatches();
   return true;
 }

diff --git a/lib/Sema/CSDiagnostics.h b/lib/Sema/CSDiagnostics.h
@@ -367,45 +367,6 @@ class MissingConformanceFailure final : public RequirementFailure {
   }
 };
 
-/// Diagnostics for mismatched generic arguments e.g
-/// ```swift
-/// struct F<G> {}
-/// let _:F<Int> = F<Bool>()
-/// ```
-class GenericArgumentsMismatchFailure final : public FailureDiagnostic {
-  BoundGenericType *Actual;
-  BoundGenericType *Required;
-  ArrayRef<unsigned> Mismatches;
-
-public:
-  GenericArgumentsMismatchFailure(Expr *expr, ConstraintSystem &cs,
-                                  BoundGenericType *actual,
-                                  BoundGenericType *required,
-                                  ArrayRef<unsigned> mismatches,
-                                  ConstraintLocator *locator)
-      : FailureDiagnostic(expr, cs, locator), Actual(actual),
-        Required(required), Mismatches(mismatches) {}
-
-  bool diagnoseAsError() override;
-
-private:
-  void emitNotesForMismatches() {
-    for (unsigned position : Mismatches) {
-      emitNoteForMismatch(position);
-    }
-  }
-
-  void emitNoteForMismatch(int mismatchPosition);
-
-  Optional<Diag<Type, Type>> getDiagnosticFor(ContextualTypePurpose context);
-
-  /// The actual type being used.
-  BoundGenericType *getActual() const { return Actual; }
-
-  /// The type needed by the generic requirement.
-  BoundGenericType *getRequired() const { return Required; }
-};
-
 /// Diagnose failures related to same-type generic requirements, e.g.
 /// ```swift
 /// protocol P {
@@ -723,8 +684,6 @@ class ContextualFailure : public FailureDiagnostic {
                                             Type contextualType);
 
 private:
-  ContextualTypePurpose getContextualTypePurpose() const { return CTP; }
-
   Type resolve(Type rawType) {
     auto type = resolveType(rawType)->getWithoutSpecifierType();
     if (auto *BGT = type->getAs<BoundGenericType>()) {
@@ -749,10 +708,55 @@ class ContextualFailure : public FailureDiagnostic {
   bool isIntegerToStringIndexConversion() const;
 
 protected:
+  ContextualTypePurpose getContextualTypePurpose() const { return CTP; }
+
   static Optional<Diag<Type, Type>>
   getDiagnosticFor(ContextualTypePurpose context, bool forProtocol);
 };
 
+/// Diagnostics for mismatched generic arguments e.g
+/// ```swift
+/// struct F<G> {}
+/// let _:F<Int> = F<Bool>()
+/// ```
+class GenericArgumentsMismatchFailure final : public ContextualFailure {
+  ArrayRef<unsigned> Mismatches;
+
+public:
+  GenericArgumentsMismatchFailure(Expr *expr, ConstraintSystem &cs,
+                                  Type actualType, Type requiredType,
+                                  ArrayRef<unsigned> mismatches,
+                                  ConstraintLocator *locator)
+      : ContextualFailure(expr, cs, actualType, requiredType, locator),
+        Mismatches(mismatches) {
+    assert(actualType->is<BoundGenericType>());
+    assert(requiredType->is<BoundGenericType>());
+  }
+
+  bool diagnoseAsError() override;
+
+private:
+  void emitNotesForMismatches() {
+    for (unsigned position : Mismatches) {
+      emitNoteForMismatch(position);
+    }
+  }
+
+  void emitNoteForMismatch(int mismatchPosition);
+
+  Optional<Diag<Type, Type>> getDiagnosticFor(ContextualTypePurpose context);
+
+  /// The actual type being used.
+  BoundGenericType *getActual() const {
+    return getFromType()->castTo<BoundGenericType>();
+  }
+
+  /// The type needed by the generic requirement.
+  BoundGenericType *getRequired() const {
+    return getToType()->castTo<BoundGenericType>();
+  }
+};
+
 /// Diagnose failures related to conversion between throwing function type
 /// and non-throwing one e.g.
 ///

diff --git a/lib/Sema/CSFix.cpp b/lib/Sema/CSFix.cpp
@@ -247,14 +247,14 @@ AllowTupleTypeMismatch::create(ConstraintSystem &cs, Type lhs, Type rhs,
 }
 
 bool GenericArgumentsMismatch::diagnose(Expr *root, bool asNote) const {
-  auto failure = GenericArgumentsMismatchFailure(root, getConstraintSystem(),
-                                                 getActual(), getRequired(),
-                                                 getMismatches(), getLocator());
+  auto &cs = getConstraintSystem();
+  GenericArgumentsMismatchFailure failure(root, cs, getFromType(), getToType(),
+                                          getMismatches(), getLocator());
   return failure.diagnose(asNote);
 }
 
 GenericArgumentsMismatch *GenericArgumentsMismatch::create(
-    ConstraintSystem &cs, BoundGenericType *actual, BoundGenericType *required,
+    ConstraintSystem &cs, Type actual, Type required,
     llvm::ArrayRef<unsigned> mismatches, ConstraintLocator *locator) {
   unsigned size = totalSizeToAlloc<unsigned>(mismatches.size());
   void *mem =

diff --git a/lib/Sema/CSFix.h b/lib/Sema/CSFix.h
@@ -569,22 +569,21 @@ class RemoveAddressOf final : public ContextualMismatch {
 /// let _:F<Int> = F<Bool>()
 /// ```
 class GenericArgumentsMismatch final
-    : public ConstraintFix,
+    : public ContextualMismatch,
       private llvm::TrailingObjects<GenericArgumentsMismatch, unsigned> {
   friend TrailingObjects;
 
-  BoundGenericType *Actual;
-  BoundGenericType *Required;
-
   unsigned NumMismatches;
 
 protected:
-  GenericArgumentsMismatch(ConstraintSystem &cs, BoundGenericType *actual,
-                           BoundGenericType *required,
+  GenericArgumentsMismatch(ConstraintSystem &cs, Type actual, Type required,
                            llvm::ArrayRef<unsigned> mismatches,
                            ConstraintLocator *locator)
-      : ConstraintFix(cs, FixKind::GenericArgumentsMismatch, locator),
-        Actual(actual), Required(required), NumMismatches(mismatches.size()) {
+      : ContextualMismatch(cs, FixKind::GenericArgumentsMismatch, actual,
+                           required, locator),
+        NumMismatches(mismatches.size()) {
+    assert(actual->is<BoundGenericType>());
+    assert(required->is<BoundGenericType>());
     std::uninitialized_copy(mismatches.begin(), mismatches.end(),
                             getMismatchesBuf().begin());
   }
@@ -594,18 +593,14 @@ class GenericArgumentsMismatch final
     return "fix generic argument mismatch";
   }
 
-  BoundGenericType *getActual() const { return Actual; }
-  BoundGenericType *getRequired() const { return Required; }
-
   ArrayRef<unsigned> getMismatches() const {
     return {getTrailingObjects<unsigned>(), NumMismatches};
   }
 
   bool diagnose(Expr *root, bool asNote = false) const override;
 
-  static GenericArgumentsMismatch *create(ConstraintSystem &cs,
-                                          BoundGenericType *actual,
-                                          BoundGenericType *required,
+  static GenericArgumentsMismatch *create(ConstraintSystem &cs, Type actual,
+                                          Type required,
                                           llvm::ArrayRef<unsigned> mismatches,
                                           ConstraintLocator *locator);
 

diff --git a/lib/Sema/CSSimplify.cpp b/lib/Sema/CSSimplify.cpp
@@ -1771,7 +1771,7 @@ ConstraintSystem::matchDeepEqualityTypes(Type type1, Type type2,
       return result;
 
     auto *fix = GenericArgumentsMismatch::create(
-        *this, bound1, bound2, mismatches, getConstraintLocator(locator));
+        *this, type1, type2, mismatches, getConstraintLocator(locator));
 
     if (!recordFix(fix)) {
       // Increase the solution's score for each mismtach this fixes.

diff --git a/test/Parse/pointer_conversion.swift.gyb b/test/Parse/pointer_conversion.swift.gyb
@@ -54,7 +54,7 @@ func mutablePointerArguments(_ p: UnsafeMutablePointer<Int>,
   var ii: [Int] = [0, 1, 2]
   var ff: [Float] = [0, 1, 2]
   takesMutablePointer(&ii)
-  takesMutablePointer(&ff) // expected-error{{cannot convert value of type '[Float]' to expected argument type 'UnsafeMutablePointer<Int>'}}
+  takesMutablePointer(&ff) // expected-error{{cannot convert value of type 'Array<Float>' to expected argument type 'UnsafeMutablePointer<Int>'}}
   // expected-note@-1 {{arguments to generic parameter 'Pointee' ('Float' and 'Int') are expected to be equal}}
   takesMutablePointer(ii) // expected-error{{cannot convert value of type '[Int]' to expected argument type 'UnsafeMutablePointer<Int>${diag_suffix}'}}
   takesMutablePointer(ff) // expected-error{{cannot convert value of type '[Float]' to expected argument type 'UnsafeMutablePointer<Int>${diag_suffix}'}}
@@ -153,10 +153,10 @@ func constPointerArguments(_ p: UnsafeMutablePointer<Int>,
   var ii: [Int] = [0, 1, 2]
   var ff: [Float] = [0, 1, 2]
   takesConstPointer(&ii)
-  takesConstPointer(&ff) // expected-error{{cannot convert value of type '[Float]' to expected argument type 'UnsafePointer<Int>'}}
+  takesConstPointer(&ff) // expected-error{{cannot convert value of type 'Array<Float>' to expected argument type 'UnsafePointer<Int>'}}
   // expected-note@-1 {{arguments to generic parameter 'Pointee' ('Float' and 'Int') are expected to be equal}}
   takesConstPointer(ii)
-  takesConstPointer(ff) // expected-error{{cannot convert value of type '[Float]' to expected argument type 'UnsafePointer<Int>'}}
+  takesConstPointer(ff) // expected-error{{cannot convert value of type 'Array<Float>' to expected argument type 'UnsafePointer<Int>'}}
   // expected-note@-1 {{arguments to generic parameter 'Pointee' ('Float' and 'Int') are expected to be equal}}
   takesConstPointer([0, 1, 2])
   // <rdar://problem/22308330> QoI: CSDiags doesn't handle array -> pointer impl conversions well
@@ -341,7 +341,7 @@ func f23202128() {
   UMP(&pipe)  // expected-error {{cannot pass immutable value as inout argument: 'pipe' is a 'let' constant}}
 
   var pipe2: [Int] = [0, 0]
-  UMP(&pipe2) // expected-error {{cannot convert value of type '[Int]' to expected argument type 'UnsafeMutablePointer<Int32>'}}
+  UMP(&pipe2) // expected-error {{cannot convert value of type 'Array<Int>' to expected argument type 'UnsafeMutablePointer<Int32>'}}
   // expected-note@-1 {{arguments to generic parameter 'Pointee' ('Int' and 'Int32') are expected to be equal}}
 
 

diff --git a/test/decl/typealias/generic.swift b/test/decl/typealias/generic.swift
@@ -278,8 +278,8 @@ let _: GenericClass<Int>.TA = GenericClass<Int>.TA<Float>(a: 1, b: 4.0)
 let _: GenericClass<Int>.TA<Float> = GenericClass.TA(a: 4.0, b: 1) // expected-error {{cannot convert value of type 'MyType<Double, Int>' to specified type 'GenericClass<Int>.TA<Float>' (aka 'MyType<Int, Float>')}}
 let _: GenericClass<Int>.TA<Float> = GenericClass.TA(a: 1, b: 4.0)
 
-let _: GenericClass<Int>.TA<Float> = GenericClass.TA<Float>(a: 4.0, b: 1) // expected-error {{cannot assign value of type 'MyType<Float, Float>' to type 'MyType<Int, Float>'}}
-let _: GenericClass<Int>.TA<Float> = GenericClass.TA<Float>(a: 1, b: 4.0) // expected-error {{cannot assign value of type 'MyType<Float, Float>' to type 'MyType<Int, Float>'}}
+let _: GenericClass<Int>.TA<Float> = GenericClass.TA<Float>(a: 4.0, b: 1) // expected-error {{cannot assign value of type 'MyType<Float, Float>' to type 'GenericClass<Int>.TA<Float>' (aka 'MyType<Int, Float>')}}
+let _: GenericClass<Int>.TA<Float> = GenericClass.TA<Float>(a: 1, b: 4.0) // expected-error {{cannot assign value of type 'MyType<Float, Float>' to type 'GenericClass<Int>.TA<Float>' (aka 'MyType<Int, Float>')}}
 
 let _: GenericClass<Int>.TA<Float> = GenericClass<Int>.TA(a: 4.0, b: 1) // expected-error {{cannot convert value of type 'Double' to expected argument type 'Int'}}
 let _: GenericClass<Int>.TA<Float> = GenericClass<Int>.TA(a: 1, b: 4.0)

diff --git a/test/expr/cast/dictionary_downcast.swift b/test/expr/cast/dictionary_downcast.swift
@@ -32,13 +32,13 @@ if let _ = dictCC as? Dictionary<D, C> { }
 if let _ = dictCC as? Dictionary<D, D> { }
 
 // Test dictionary downcasts to unrelated types.
-dictCC as Dictionary<D, U> // expected-error{{cannot convert value of type '[C : C]' to type '[D : U]' in coercion}}
+dictCC as Dictionary<D, U> // expected-error{{cannot convert value of type '[C : C]' to type 'Dictionary<D, U>' in coercion}}
 // expected-note@-1 {{arguments to generic parameter 'Key' ('C' and 'D') are expected to be equal}}
 // expected-note@-2 {{arguments to generic parameter 'Value' ('C' and 'U') are expected to be equal}}
-dictCC as Dictionary<U, D> // expected-error{{cannot convert value of type '[C : C]' to type '[U : D]' in coercion}}
+dictCC as Dictionary<U, D> // expected-error{{cannot convert value of type '[C : C]' to type 'Dictionary<U, D>' in coercion}}
 // expected-note@-1 {{arguments to generic parameter 'Key' ('C' and 'U') are expected to be equal}}
 // expected-note@-2 {{arguments to generic parameter 'Value' ('C' and 'D') are expected to be equal}}
-dictCC as Dictionary<U, U> // expected-error{{cannot convert value of type '[C : C]' to type '[U : U]' in coercion}}
+dictCC as Dictionary<U, U> // expected-error{{cannot convert value of type '[C : C]' to type 'Dictionary<U, U>' in coercion}}
 // expected-note@-1 {{arguments to generic parameter 'Key' ('C' and 'U') are expected to be equal}}
 // expected-note@-2 {{arguments to generic parameter 'Value' ('C' and 'U') are expected to be equal}}
 

diff --git a/test/expr/unary/keypath/salvage-with-other-type-errors.swift b/test/expr/unary/keypath/salvage-with-other-type-errors.swift
@@ -4,7 +4,7 @@
 // to diagnose other errors in adjacent exprs.
 
 struct P<T: K> { }
-// expected-note@-1 {{arguments to generic parameter 'T' ('String' and '_') are expected to be equal}}
+// expected-note@-1 {{arguments to generic parameter 'T' ('String' and 'T') are expected to be equal}}
 
 struct S {
     init<B>(_ a: P<B>) {
@@ -28,7 +28,7 @@ struct A {
 }
 
 extension A: K {
-    static let j = S(\A.id + "id") // expected-error {{cannot convert value of type 'P<String>' to expected argument type 'P<_>'}}
+    static let j = S(\A.id + "id") // expected-error {{cannot convert value of type 'P<String>' to expected argument type 'P<T>'}}
 }
 
 // SR-5034