[NFC] Add Type::isOrHasOptimizedCOW api

Author: meg-gupta

SwiftCompilerSources/Sources/AST/Type.swift

@@ -158,6 +158,9 @@ extension TypeProperties {
   /// True if this the nominal type `Swift.Optional`.
   public var isOptional: Bool { rawType.bridged.isOptional() }
 
+  /// True if this has optimized COW type: Array/ArraySlice/ContiguousArray
+  public var isOrHasOptimizedCOW: Bool {rawType.bridged.isOrHasOptimizedCOW()}
+
   /// True if this type is a value type (struct/enum) that defines a `deinit`.
   public var isValueTypeWithDeinit: Bool {
     if let nominal = nominal, nominal.valueTypeDestructor != nil {

include/swift/AST/ASTBridging.h

@@ -3105,6 +3105,7 @@ struct BridgedASTType {
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTType getBuiltinVectorElementType() const;
   BRIDGED_INLINE bool isBuiltinFixedWidthInteger(SwiftInt width) const;
   BRIDGED_INLINE bool isOptional() const;
+  BRIDGED_INLINE bool isOrHasOptimizedCOW() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE OptionalBridgedDeclObj getNominalOrBoundGenericNominal() const;
   BRIDGED_INLINE TraitResult canBeClass() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE OptionalBridgedDeclObj getAnyNominal() const;

include/swift/AST/ASTBridgingImpl.h

@@ -552,6 +552,10 @@ bool BridgedASTType::isOptional() const {
   return unbridged()->getCanonicalType()->isOptional();
 }
 
+bool BridgedASTType::isOrHasOptimizedCOW() const {
+  return unbridged()->getCanonicalType()->isOrHasOptimizedCOW();
+}
+
 bool BridgedASTType::isUnownedStorageType() const {
   return unbridged()->is<swift::UnownedStorageType>();
 }

include/swift/AST/KnownStdlibTypes.def

@@ -50,6 +50,7 @@ KNOWN_STDLIB_TYPE_DECL(StaticString, NominalTypeDecl, 0)
 KNOWN_STDLIB_TYPE_DECL(Substring, NominalTypeDecl, 0)
 KNOWN_STDLIB_TYPE_DECL(Array, NominalTypeDecl, 1)
 KNOWN_STDLIB_TYPE_DECL(ArraySlice, NominalTypeDecl, 1)
+KNOWN_STDLIB_TYPE_DECL(ContiguousArray, NominalTypeDecl, 1)
 KNOWN_STDLIB_TYPE_DECL(_ArrayBuffer, NominalTypeDecl, 1)
 KNOWN_STDLIB_TYPE_DECL(_ContiguousArrayBuffer, NominalTypeDecl, 1)
 KNOWN_STDLIB_TYPE_DECL(_ContiguousArrayStorage, ClassDecl, 1)

include/swift/AST/Types.h

@@ -991,6 +991,9 @@ class alignas(1 << TypeAlignInBits) TypeBase
   /// element type of the array.
   Type isArrayType();
 
+  /// Check if this type is or has Swift.Array recursively.
+  bool isOrHasOptimizedCOW() const;
+
   /// Determines the element type of a known
   /// [Autoreleasing]Unsafe[Mutable][Raw]Pointer variant, or returns null if the
   /// type is not a pointer.

lib/AST/Type.cpp

@@ -840,6 +840,18 @@ Type TypeBase::isArrayType() {
   return Type();
 }
 
+bool TypeBase::isOrHasOptimizedCOW() const {
+  bool foundOptCOWType = false;
+  getCanonicalType().findIf([&](Type type) -> bool {
+    if (type->isArray() || type->isArraySlice() || type->isContiguousArray()) {
+      foundOptCOWType = true;
+      return true;
+    };
+    return true;
+  });
+  return foundOptCOWType;
+}
+
 Type TypeBase::getAnyPointerElementType(PointerTypeKind &PTK) {
   auto &C = getASTContext();
   if (isUnsafeMutableRawPointer()) {