Merge pull request #18336 from rudkx/function-types

Replace some uses of getInput().

Author: rudkx

include/swift/AST/Types.h

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -2861,6 +2861,9 @@ class AnyFunctionType : public TypeBase {
   static bool equalParams(ArrayRef<AnyFunctionType::Param> a,
                           ArrayRef<AnyFunctionType::Param> b);
 
+  /// \brief Given two arrays of parameters determine if they are equal.
+  static bool equalParams(CanParamArrayRef a, CanParamArrayRef b);
+
   Type getInput() const { return Input; }
   Type getResult() const { return Output; }
   ArrayRef<AnyFunctionType::Param> getParams() const;

lib/AST/ASTContext.cpp

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -3608,6 +3608,18 @@ bool AnyFunctionType::equalParams(ArrayRef<AnyFunctionType::Param> a,
   return true;
 }
 
+bool AnyFunctionType::equalParams(CanParamArrayRef a, CanParamArrayRef b) {
+  if (a.size() != b.size())
+    return false;
+
+  for (unsigned i = 0, n = a.size(); i != n; ++i) {
+    if (a[i] != b[i])
+      return false;
+  }
+
+  return true;
+}
+
 FunctionType *FunctionType::get(ArrayRef<AnyFunctionType::Param> params,
                                 Type result, const ExtInfo &info,
                                 bool canonicalVararg) {

lib/AST/TypeJoinMeet.cpp

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -324,9 +324,8 @@ CanType TypeJoin::visitFunctionType(CanType second) {
   if (firstExtInfo.withNoEscape(false) != secondExtInfo.withNoEscape(false))
     return Unimplemented;
 
-  // FIXME: Properly compute parameter types from getParams().
-  if (firstFnTy->getInput()->getCanonicalType() !=
-      secondFnTy->getInput()->getCanonicalType())
+  if (!AnyFunctionType::equalParams(firstFnTy->getParams(),
+                                    secondFnTy->getParams()))
     return Unimplemented;
 
   auto firstResult = firstFnTy->getResult()->getCanonicalType();
@@ -340,8 +339,8 @@ CanType TypeJoin::visitFunctionType(CanType second) {
   if (secondFnTy->getExtInfo().isNoEscape())
     extInfo = extInfo.withNoEscape(true);
 
-  return FunctionType::get(firstFnTy->getInput(), result,
-                           extInfo)->getCanonicalType();
+  return FunctionType::get(firstFnTy->getParams(), result, extInfo)
+      ->getCanonicalType();
 }
 
 CanType TypeJoin::visitGenericFunctionType(CanType second) {

lib/SIL/DynamicCasts.cpp

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -485,22 +485,12 @@ swift::classifyDynamicCast(ModuleDecl *M,
       if (targetFunction->getRepresentation()
             != sourceFunction->getRepresentation())
         return DynamicCastFeasibility::WillFail;
-      
-      if (sourceFunction.getInput() == targetFunction.getInput()
-          && sourceFunction.getResult() == targetFunction.getResult())
+
+      if (AnyFunctionType::equalParams(sourceFunction.getParams(),
+                                       targetFunction.getParams()) &&
+          sourceFunction.getResult() == targetFunction.getResult())
         return DynamicCastFeasibility::WillSucceed;
 
-      auto isSubstitutable = [](CanType a, CanType b) -> bool {
-        // FIXME: Unnecessarily conservative; should structurally check for
-        // substitutability.
-        return a == b || a->hasArchetype() || b->hasArchetype();
-      };
-    
-      if (isSubstitutable(sourceFunction.getInput(), targetFunction.getInput())
-          && isSubstitutable(targetFunction.getInput(),
-                             targetFunction.getResult()))
-        return DynamicCastFeasibility::MaySucceed;
-      
       return DynamicCastFeasibility::WillFail;
     }
   }