[SILGen] Handled transforming Bridged? -> Swift.

nate-chandler · nate-chandler · commit 99d0b792cc91 · 2021-08-16T17:36:27.000-07:00
Previously, the function emitCBridgedToNativeValue handled three
situations around optionals:
- Bridged?, Native?
- Bridged, Native?
- Bridged, Native

Here, handling for the fourth case
- Bridged?, Native
is added.

To enable this, the number of Optional wrappings that the bridged type
has that the native type does not is passed in to the function.  Then,
in the portions of the function where actual transformations are done,
the values are unwrapped an appropriate number of times.  Mostly that
means force unwrapping N times before doing the transformation.  In the
case of types that conform to _ObjectiveCBridgeable, however, it means
force unwrapping the value N-1 times after doing the transformation
because _ObjectiveCBridgeable._unconditionallyBridgeFromObjectiveC
performs one layer of unwrapping itself.

rdar://81590807
diff --git a/lib/SILGen/SILGenBridging.cpp b/lib/SILGen/SILGenBridging.cpp
@@ -1019,16 +1019,11 @@ SILGenFunction::emitBlockToFunc(SILLocation loc,
       loc, thunkedFn, SILType::getPrimitiveObjectType(loweredFuncTy));
 }
 
-static ManagedValue emitCBridgedToNativeValue(SILGenFunction &SGF,
-                                              SILLocation loc,
-                                              ManagedValue v,
-                                              CanType bridgedType,
-                                              CanType nativeType,
-                                              SILType loweredNativeTy,
-                                              bool isCallResult,
-                                              SGFContext C) {
+static ManagedValue emitCBridgedToNativeValue(
+    SILGenFunction &SGF, SILLocation loc, ManagedValue v, CanType bridgedType,
+    SILType loweredBridgedTy, CanType nativeType, SILType loweredNativeTy,
+    int bridgedOptionalsToUnwrap, bool isCallResult, SGFContext C) {
   assert(loweredNativeTy.isObject());
-  SILType loweredBridgedTy = v.getType();
   if (loweredNativeTy == loweredBridgedTy.getObjectType())
     return v;
 
@@ -1039,37 +1034,50 @@ static ManagedValue emitCBridgedToNativeValue(SILGenFunction &SGF,
     if (!bridgedObjectType) {
       auto helper = [&](SILGenFunction &SGF, SILLocation loc, SGFContext C) {
         auto loweredNativeObjectTy = loweredNativeTy.getOptionalObjectType();
-        return emitCBridgedToNativeValue(SGF, loc, v, bridgedType,
-                                         nativeObjectType,
-                                         loweredNativeObjectTy,
-                                         isCallResult, C);
+        return emitCBridgedToNativeValue(
+            SGF, loc, v, bridgedType, loweredBridgedTy, nativeObjectType,
+            loweredNativeObjectTy, bridgedOptionalsToUnwrap, isCallResult, C);
       };
       return SGF.emitOptionalSome(loc, loweredNativeTy, helper, C);
     }
 
     // Optional-to-optional.
-    auto helper =
-        [=](SILGenFunction &SGF, SILLocation loc, ManagedValue v,
-            SILType loweredNativeObjectTy, SGFContext C) {
-      return emitCBridgedToNativeValue(SGF, loc, v, bridgedObjectType,
-                                       nativeObjectType, loweredNativeObjectTy,
-                                       isCallResult, C);
+    auto helper = [=](SILGenFunction &SGF, SILLocation loc, ManagedValue v,
+                      SILType loweredNativeObjectTy, SGFContext C) {
+      return emitCBridgedToNativeValue(
+          SGF, loc, v, bridgedObjectType,
+          loweredBridgedTy.getOptionalObjectType(), nativeObjectType,
+          loweredNativeObjectTy, bridgedOptionalsToUnwrap, isCallResult, C);
     };
     return SGF.emitOptionalToOptional(loc, v, loweredNativeTy, helper, C);
   }
+  if (auto bridgedObjectType = bridgedType.getOptionalObjectType()) {
+    return emitCBridgedToNativeValue(
+        SGF, loc, v, bridgedObjectType,
+        loweredBridgedTy.getOptionalObjectType(), nativeType, loweredNativeTy,
+        bridgedOptionalsToUnwrap + 1, isCallResult, C);
+  }
+
+  auto unwrapBridgedOptionals = [&](ManagedValue v) {
+    for (int i = 0; i < bridgedOptionalsToUnwrap; ++i) {
+      v = SGF.emitPreconditionOptionalHasValue(loc, v,
+                                               /*implicit*/ true);
+    };
+    return v;
+  };
 
   // Bridge ObjCBool, DarwinBoolean, WindowsBool to Bool when requested.
   if (nativeType == SGF.SGM.Types.getBoolType()) {
     if (bridgedType == SGF.SGM.Types.getObjCBoolType()) {
-      return emitBridgeForeignBoolToBool(SGF, loc, v,
+      return emitBridgeForeignBoolToBool(SGF, loc, unwrapBridgedOptionals(v),
                                          SGF.SGM.getObjCBoolToBoolFn());
     }
     if (bridgedType == SGF.SGM.Types.getDarwinBooleanType()) {
-      return emitBridgeForeignBoolToBool(SGF, loc, v,
+      return emitBridgeForeignBoolToBool(SGF, loc, unwrapBridgedOptionals(v),
                                          SGF.SGM.getDarwinBooleanToBoolFn());
     }
     if (bridgedType == SGF.SGM.Types.getWindowsBoolType()) {
-      return emitBridgeForeignBoolToBool(SGF, loc, v,
+      return emitBridgeForeignBoolToBool(SGF, loc, unwrapBridgedOptionals(v),
                                          SGF.SGM.getWindowsBoolToBoolFn());
     }
   }
@@ -1079,8 +1087,8 @@ static ManagedValue emitCBridgedToNativeValue(SILGenFunction &SGF,
     auto bridgedMetaTy = cast<AnyMetatypeType>(bridgedType);
     if (bridgedMetaTy->hasRepresentation() &&
         bridgedMetaTy->getRepresentation() == MetatypeRepresentation::ObjC) {
-      SILValue native =
-        SGF.B.emitObjCToThickMetatype(loc, v.getValue(), loweredNativeTy);
+      SILValue native = SGF.B.emitObjCToThickMetatype(
+          loc, unwrapBridgedOptionals(v).getValue(), loweredNativeTy);
       // *NOTE*: ObjCMetatypes are trivial types. They only gain ARC semantics
       // when they are converted to an object via objc_metatype_to_object.
       assert(!v.hasCleanup() && "Metatypes are trivial and should not have "
@@ -1096,7 +1104,8 @@ static ManagedValue emitCBridgedToNativeValue(SILGenFunction &SGF,
           == AnyFunctionType::Representation::Block
         && nativeFTy->getRepresentation()
           != AnyFunctionType::Representation::Block) {
-      return SGF.emitBlockToFunc(loc, v, bridgedFTy, nativeFTy,
+      return SGF.emitBlockToFunc(loc, unwrapBridgedOptionals(v), bridgedFTy,
+                                 nativeFTy,
                                  loweredNativeTy.castTo<SILFunctionType>());
     }
   }
@@ -1105,8 +1114,10 @@ static ManagedValue emitCBridgedToNativeValue(SILGenFunction &SGF,
   if (auto conformance =
         SGF.SGM.getConformanceToObjectiveCBridgeable(loc, nativeType)) {
     if (auto result = emitBridgeObjectiveCToNative(SGF, loc, v, bridgedType,
-                                                   conformance))
-      return *result;
+                                                   conformance)) {
+      --bridgedOptionalsToUnwrap;
+      return unwrapBridgedOptionals(*result);
+    }
 
     assert(SGF.SGM.getASTContext().Diags.hadAnyError() &&
            "Bridging code should have complained");
@@ -1117,7 +1128,8 @@ static ManagedValue emitCBridgedToNativeValue(SILGenFunction &SGF,
   if (nativeType->isAny()) {
     // If this is not a call result, use the normal erasure logic.
     if (!isCallResult) {
-      return SGF.emitTransformedValue(loc, v, bridgedType, nativeType, C);
+      return SGF.emitTransformedValue(loc, unwrapBridgedOptionals(v),
+                                      bridgedType, nativeType, C);
     }
 
     // Otherwise, we use more complicated logic that handles results that
@@ -1129,7 +1141,8 @@ static ManagedValue emitCBridgedToNativeValue(SILGenFunction &SGF,
     CanType anyObjectTy =
       SGF.getASTContext().getAnyObjectType()->getCanonicalType();
     if (bridgedType != anyObjectTy) {
-      v = SGF.emitTransformedValue(loc, v, bridgedType, anyObjectTy);
+      v = SGF.emitTransformedValue(loc, unwrapBridgedOptionals(v), bridgedType,
+                                   anyObjectTy);
     }
 
     // TODO: Ever need to handle +0 values here?
@@ -1142,8 +1155,8 @@ static ManagedValue emitCBridgedToNativeValue(SILGenFunction &SGF,
     // Bitcast to Optional. This provides a barrier to the optimizer to prevent
     // it from attempting to eliminate null checks.
     auto optionalBridgedTy = SILType::getOptionalType(loweredBridgedTy);
-    auto optionalMV =
-      SGF.B.createUncheckedBitCast(loc, v, optionalBridgedTy);
+    auto optionalMV = SGF.B.createUncheckedBitCast(
+        loc, unwrapBridgedOptionals(v), optionalBridgedTy);
     return SGF.emitApplyOfLibraryIntrinsic(loc,
                            SGF.getASTContext().getBridgeAnyObjectToAny(),
                            SubstitutionMap(), optionalMV, C)
@@ -1152,9 +1165,9 @@ static ManagedValue emitCBridgedToNativeValue(SILGenFunction &SGF,
 
   // Bridge NSError to Error.
   if (bridgedType == SGF.SGM.Types.getNSErrorType())
-    return SGF.emitBridgedToNativeError(loc, v);
+    return SGF.emitBridgedToNativeError(loc, unwrapBridgedOptionals(v));
 
-  return v;
+  return unwrapBridgedOptionals(v);
 }
 
 ManagedValue SILGenFunction::emitBridgedToNativeValue(SILLocation loc,
@@ -1165,8 +1178,10 @@ ManagedValue SILGenFunction::emitBridgedToNativeValue(SILLocation loc,
                                                       SGFContext C,
                                                       bool isCallResult) {
   loweredNativeTy = loweredNativeTy.getObjectType();
-  return emitCBridgedToNativeValue(*this, loc, v, bridgedType, nativeType,
-                                   loweredNativeTy, isCallResult, C);
+  SILType loweredBridgedTy = v.getType();
+  return emitCBridgedToNativeValue(
+      *this, loc, v, bridgedType, loweredBridgedTy, nativeType, loweredNativeTy,
+      /*bridgedOptionalsToUnwrap=*/0, isCallResult, C);
 }
 
 /// Bridge a possibly-optional foreign error type to Error.
diff --git a/test/Inputs/clang-importer-sdk/usr/include/ObjCConcurrency.h b/test/Inputs/clang-importer-sdk/usr/include/ObjCConcurrency.h
@@ -84,6 +84,10 @@ typedef void (^CompletionHandler)(NSString * _Nullable, NSString * _Nullable_res
 -(void)asyncImportSame:(NSString *)operation replyTo:(void (^)(NSInteger))handler __attribute__((swift_async(none)));
 
 -(void)overridableButRunsOnMainThreadWithCompletionHandler:(MAIN_ACTOR_UNSAFE void (^ _Nullable)(NSString *))completion;
+- (void)obtainClosureWithCompletionHandler:(void (^)(void (^_Nullable)(void),
+                                                     NSError *_Nullable,
+                                                     BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3)));
 @end
 
 @protocol RefrigeratorDelegate<NSObject>
diff --git a/test/SILGen/objc_async.swift b/test/SILGen/objc_async.swift
@@ -85,6 +85,8 @@ func testSlowServer(slowServer: SlowServer) async throws {
   let _: ((Any) -> Void, (Any) -> Void) = await slowServer.performId2VoidId2Void()
 
   let _: String = try await slowServer.findAnswerFailingly()
+
+  let _: () -> Void = try await slowServer.obtainClosure()
 }
 
 func testGeneric<T: AnyObject>(x: GenericObject<T>) async throws {
diff --git a/validation-test/compiler_crashers_2_fixed/Inputs/rdar81590807.h b/validation-test/compiler_crashers_2_fixed/Inputs/rdar81590807.h
@@ -0,0 +1,29 @@
+#include <Foundation/Foundation.h>
+
+#pragma clang assume_nonnull begin
+
+@interface PFXObject : NSObject {
+}
+- (void)continuePassSyncWithCompletionHandler:(void (^)(void (^_Nullable)(void),
+                                                        NSError *_Nullable,
+                                                        BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3)));
+- (void)continuePassAsyncWithCompletionHandler:
+    (void (^)(void (^_Nullable)(void), NSError *_Nullable,
+              BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3)));
+- (void)continueFailSyncWithCompletionHandler:(void (^)(void (^_Nullable)(void),
+                                                        NSError *_Nullable,
+                                                        BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3)));
+- (void)continueFailAsyncWithCompletionHandler:
+    (void (^)(void (^_Nullable)(void), NSError *_Nullable,
+              BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3)));
+- (void)continueIncorrectWithCompletionHandler:
+    (void (^)(void (^_Nullable)(void), NSError *_Nullable,
+              BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3)));
+@end
+
+#pragma clang assume_nonnull end
diff --git a/validation-test/compiler_crashers_2_fixed/Inputs/rdar81590807.m b/validation-test/compiler_crashers_2_fixed/Inputs/rdar81590807.m
@@ -0,0 +1,54 @@
+#include "rdar81590807.h"
+
+#pragma clang assume_nonnull begin
+
+@implementation PFXObject
+- (void)continuePassSyncWithCompletionHandler:(void (^)(void (^_Nullable)(void),
+                                                        NSError *_Nullable,
+                                                        BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3))) {
+  completionHandler(
+      ^{
+        NSLog(@"passSync");
+      },
+      NULL, YES);
+}
+- (void)continuePassAsyncWithCompletionHandler:
+    (void (^)(void (^_Nullable)(void), NSError *_Nullable,
+              BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3))) {
+  dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0), ^{
+    completionHandler(
+        ^{
+          NSLog(@"passAsync");
+        },
+        NULL, YES);
+  });
+}
+- (void)continueFailSyncWithCompletionHandler:(void (^)(void (^_Nullable)(void),
+                                                        NSError *_Nullable,
+                                                        BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3))) {
+  completionHandler(
+      NULL, [NSError errorWithDomain:@"failSync" code:1 userInfo:nil], NO);
+}
+- (void)continueFailAsyncWithCompletionHandler:
+    (void (^)(void (^_Nullable)(void), NSError *_Nullable,
+              BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3))) {
+  dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0), ^{
+    completionHandler(
+        NULL, [NSError errorWithDomain:@"failAsync" code:2 userInfo:nil], NO);
+  });
+}
+- (void)continueIncorrectWithCompletionHandler:
+    (void (^)(void (^_Nullable)(void), NSError *_Nullable,
+              BOOL))completionHandler
+    __attribute__((swift_async_error(zero_argument, 3))) {
+  dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0), ^{
+    completionHandler(NULL, NULL, NO);
+  });
+}
+@end
+
+#pragma clang assume_nonnull end
diff --git a/validation-test/compiler_crashers_2_fixed/Inputs/rdar81590807_2.h b/validation-test/compiler_crashers_2_fixed/Inputs/rdar81590807_2.h
@@ -0,0 +1,24 @@
+#include <Foundation/Foundation.h>
+
+#pragma clang assume_nonnull begin
+
+@interface PFXObject : NSObject {
+}
+- (void)findAnswerSyncSuccessAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerSyncSuccess(completionHandler:)")));
+- (void)findAnswerAsyncSuccessAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerAsyncSuccess(completionHandler:)")));
+- (void)findAnswerSyncFailAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerSyncFail(completionHandler:)")));
+- (void)findAnswerAsyncFailAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerAsyncFail(completionHandler:)")));
+- (void)findAnswerIncorrectAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerIncorrect(completionHandler:)")));
+@end
+
+#pragma clang assume_nonnull end
diff --git a/validation-test/compiler_crashers_2_fixed/Inputs/rdar81590807_2.m b/validation-test/compiler_crashers_2_fixed/Inputs/rdar81590807_2.m
@@ -0,0 +1,37 @@
+#include "rdar81590807_2.h"
+
+#pragma clang assume_nonnull begin
+
+@implementation PFXObject
+- (void)findAnswerSyncSuccessAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerSyncSuccess(completionHandler:)"))) {
+  handler(@"syncSuccess", NULL);
+}
+- (void)findAnswerAsyncSuccessAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerAsyncSuccess(completionHandler:)"))) {
+  dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0), ^{
+    handler(@"asyncSuccess", NULL);
+  });
+}
+- (void)findAnswerSyncFailAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerSyncFail(completionHandler:)"))) {
+  handler(NULL, [NSError errorWithDomain:@"syncFail" code:1 userInfo:nil]);
+}
+- (void)findAnswerAsyncFailAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerAsyncFail(completionHandler:)"))) {
+  dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0), ^{
+    handler(NULL, [NSError errorWithDomain:@"asyncFail" code:2 userInfo:nil]);
+  });
+}
+- (void)findAnswerIncorrectAsynchronously:
+    (void (^)(NSString *_Nullable, NSError *_Nullable))handler
+    __attribute__((swift_name("findAnswerIncorrect(completionHandler:)"))) {
+  handler(NULL, NULL);
+}
+@end
+
+#pragma clang assume_nonnull end
diff --git a/validation-test/compiler_crashers_2_fixed/rdar81590807.swift b/validation-test/compiler_crashers_2_fixed/rdar81590807.swift
@@ -0,0 +1,50 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-clang %S/Inputs/rdar81590807.m -I %S/Inputs -c -o %t/rdar81590807.o
+// RUN: %target-build-swift -Xfrontend -disable-availability-checking -import-objc-header %S/Inputs/rdar81590807.h -Xlinker %t/rdar81590807.o -parse-as-library %s -o %t/main
+// RUN: %target-codesign %t/main
+// RUN: %target-run %t/main > %t/log 2>&1 || true
+// RUN: %FileCheck %s < %t/log
+
+// Unsupported because the crash on continueIncorrect is just an illegal 
+// instruction rather than a nice fatal error.
+// UNSUPPORTED: swift_test_mode_optimize
+// UNSUPPORTED: swift_test_mode_optimize_size
+
+// REQUIRES: executable_test
+// REQUIRES: OS=macosx || OS=ios
+
+func run(on object: PFXObject) async throws {
+  // CHECK: passSync
+  let cl1 = try await object.continuePassSync()
+  cl1()
+  // CHECK: passAsync
+  let cl2 = try await object.continuePassAsync()
+  cl2()
+  do {
+    let cl = try await object.continueFailSync()
+    // CHECK-NOT: oh no failSync
+    fputs("oh no failSync\n", stderr)
+  }
+  catch let error {
+    // CHECK: Error Domain=failSync Code=1 "(null)"
+    fputs("\(error)\n", stderr)
+  }
+  do {
+    let cl = try await object.continueFailAsync()
+    // CHECK-NOT: oh no failAsync
+    fputs("oh no failAsync\n", stderr)
+  }
+  catch let error {
+    // CHECK: Error Domain=failAsync Code=2 "(null)"
+    fputs("\(error)\n", stderr)
+  }
+  // CHECK: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value
+  print(try await object.continueIncorrect())
+}
+
+@main struct Main {
+  static func main() async throws {
+    let object = PFXObject()
+    try await run(on: object)
+  }
+}
diff --git a/validation-test/compiler_crashers_2_fixed/rdar81590807_2.swift b/validation-test/compiler_crashers_2_fixed/rdar81590807_2.swift

Original file line number	Diff line number	Diff line change
`@@ -85,6 +85,8 @@ func testSlowServer(slowServer: SlowServer) async throws {`
`85`	`85`	`let _: ((Any) -> Void, (Any) -> Void) = await slowServer.performId2VoidId2Void()`
`86`	`86`
`87`	`87`	`let _: String = try await slowServer.findAnswerFailingly()`
	`88`	`+`
	`89`	`+ let _: () -> Void = try await slowServer.obtainClosure()`
`88`	`90`	`}`
`89`	`91`
`90`	`92`	`func testGeneric<T: AnyObject>(x: GenericObject<T>) async throws {`