Revert "[ObjC Interop] Map Swift @objc properties named isFoo to ObjC Cocoa conventions" (#3254)

It sounds good on paper, but in practice we ended up breaking Core Data
projects (because people name their boolean properties 'isFoo' rather
than the Objective-C 'foo'), forcing an Objective-C-side change when
a mixed-source project upgrades to Swift 3, and causing collisions when
there are properties named both 'foo' and 'isFoo'. If people care about
their Swift boolean properties strictly following the Objective-C Cocoa
naming conventions, they'll have to specify them manually.

(We do have a bug to make it easier to rename the getter of a stored
property exposed to Objective-C: rdar://problem/21261564.)

This reverts commit 6fe6266.

rdar://problem/26847223

Author: jrose-apple

include/swift/AST/Decl.h

@@ -4322,6 +4322,11 @@ class VarDecl : public AbstractStorageDecl {
   /// Return the Objective-C runtime name for this property.
   Identifier getObjCPropertyName() const;
 
+  /// Retrieve the default Objective-C selector for the getter of a
+  /// property of the given name.
+  static ObjCSelector getDefaultObjCGetterSelector(ASTContext &ctx,
+                                                   Identifier propertyName);
+
   /// Retrieve the default Objective-C selector for the setter of a
   /// property of the given name.
   static ObjCSelector getDefaultObjCSetterSelector(ASTContext &ctx,

lib/AST/Decl.cpp

@@ -3222,14 +3222,9 @@ ObjCSelector AbstractStorageDecl::getObjCGetterSelector(
     }
   }
 
-  // If the Swift name starts with the word "is", use that Swift name as the
-  // getter name.
-  auto var = cast<VarDecl>(this);
-  if (camel_case::getFirstWord(var->getName().str()) == "is")
-    return ObjCSelector(ctx, 0, { var->getName() });
-
   // The getter selector is the property name itself.
-  return ObjCSelector(ctx, 0, { var->getObjCPropertyName() });
+  auto var = cast<VarDecl>(this);
+  return VarDecl::getDefaultObjCGetterSelector(ctx, var->getObjCPropertyName());
 }
 
 ObjCSelector AbstractStorageDecl::getObjCSetterSelector(
@@ -3515,25 +3510,21 @@ Identifier VarDecl::getObjCPropertyName() const {
       return name->getSelectorPieces()[0];
   }
 
-  // If the Swift property name starts with the word "is", strip the
-  // "is" and lowercase the rest when forming the Objective-C property
-  // name.
-  ASTContext &ctx = getASTContext();
-  StringRef nameStr = getName().str();
-  if (camel_case::getFirstWord(nameStr) == "is") {
-    SmallString<16> scratch;
-    return ctx.getIdentifier(camel_case::toLowercaseWord(nameStr.substr(2),
-                                                         scratch));
-  }
-
   return getName();
 }
 
+ObjCSelector VarDecl::getDefaultObjCGetterSelector(ASTContext &ctx,
+                                                   Identifier propertyName) {
+  return ObjCSelector(ctx, 0, propertyName);
+}
+
+
 ObjCSelector VarDecl::getDefaultObjCSetterSelector(ASTContext &ctx,
                                                    Identifier propertyName) {
   llvm::SmallString<16> scratch;
   scratch += "set";
   camel_case::appendSentenceCase(scratch, propertyName.str());
+
   return ObjCSelector(ctx, 1, ctx.getIdentifier(scratch));
 }
 

lib/PrintAsObjC/PrintAsObjC.cpp

@@ -667,7 +667,8 @@ class ObjCPrinter : private DeclVisitor<ObjCPrinter>,
     // Handle custom accessor names.
     llvm::SmallString<64> buffer;
     if (hasReservedName ||
-        VD->getObjCGetterSelector() != ObjCSelector(ctx, 0, { objCName })) {
+        VD->getObjCGetterSelector() !=
+          VarDecl::getDefaultObjCGetterSelector(ctx, objCName)) {
       os << ", getter=" << VD->getObjCGetterSelector().getString(buffer);
     }
     if (isSettable) {

test/PrintAsObjC/classes.swift

@@ -420,7 +420,7 @@ public class NonObjCClass { }
 // CHECK-NEXT: + (NSDictionary<NSString *, NSString *> * _Nonnull)staticDictionary;
 // CHECK-NEXT: @property (nonatomic, strong) Properties * _Nullable wobble;
 // CHECK-NEXT: @property (nonatomic, getter=isEnabled, setter=setIsEnabled:) BOOL enabled;
-// CHECK-NEXT: @property (nonatomic, getter=isAnimated) BOOL animated;
+// CHECK-NEXT: @property (nonatomic) BOOL isAnimated;
 // CHECK-NEXT: @property (nonatomic, getter=register, setter=setRegister:) BOOL register_;
 // CHECK-NEXT: @property (nonatomic, readonly, strong, getter=this) Properties * _Nonnull this_;
 // CHECK-NEXT: @property (nonatomic, readonly) NSInteger privateSetter;

test/SILGen/objc_selector.swift

@@ -21,7 +21,7 @@ func createSelector(foo: Foo) -> Selector {
 
 // CHECK-LABEL: sil hidden @{{.*}}createGetterSelector
 func createGetterSelector() -> Selector {
-  // CHECK: string_literal objc_selector "isProperty"
+  // CHECK: string_literal objc_selector "property"
   return #selector(getter: Foo.isProperty)
 }