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[Clang importer] Don't bridge blocks to Swift functions in ObjC generic args #17247

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Merged
merged 2 commits into from
Jun 15, 2018
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[Clang importer] Don't bridge blocks to Swift functions in ObjC generic args #17247

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d529002
[Clang importer] Don't bridge blocks to Swift functions in ObjC gener…
DougGregor Jun 15, 2018
f595ca7
[Clang importer] Rename ImportTypeKind::ObjCGenericArgument -> ObjCCo…
DougGregor Jun 15, 2018
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26 changes: 20 additions & 6 deletions lib/ClangImporter/ImportType.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -974,8 +974,8 @@ namespace {
// Convert the type arguments.
for (auto typeArg : typeArgs) {
Type importedTypeArg = Impl.importTypeIgnoreIUO(
typeArg, ImportTypeKind::BridgedValue, AllowNSUIntegerAsInt,
Bridging, OTK_None);
typeArg, ImportTypeKind::ObjCCollectionElement,
AllowNSUIntegerAsInt, Bridging, OTK_None);
if (!importedTypeArg) {
importedTypeArgs.clear();
break;
Expand Down Expand Up @@ -1102,7 +1102,7 @@ static bool canBridgeTypes(ImportTypeKind importKind) {
case ImportTypeKind::CFUnretainedOutParameter:
case ImportTypeKind::Property:
case ImportTypeKind::PropertyWithReferenceSemantics:
case ImportTypeKind::BridgedValue:
case ImportTypeKind::ObjCCollectionElement:
case ImportTypeKind::Typedef:
return true;
}
Expand All @@ -1116,7 +1116,7 @@ static bool isCFAudited(ImportTypeKind importKind) {
case ImportTypeKind::Abstract:
case ImportTypeKind::Typedef:
case ImportTypeKind::Value:
case ImportTypeKind::BridgedValue:
case ImportTypeKind::ObjCCollectionElement:
case ImportTypeKind::Variable:
case ImportTypeKind::Result:
case ImportTypeKind::Pointee:
Expand Down Expand Up @@ -1287,10 +1287,24 @@ static ImportedType adjustTypeForConcreteImport(
// we would prefer to instead use the default Swift convention.
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Sorry, I meant this comment, which refers to @convention(block).

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Grrrr. That comment above is a lie. I'll do a separate comment-only PR for that

if (hint == ImportHint::Block) {
if (canBridgeTypes(importKind)) {
// Determine the function type representation we need.
//
// For Objective-C collection arguments, we cannot bridge from a block
// to a Swift function type, so force the block representation. Normally
// the mapped type will have a block representation (making this a no-op),
// but in cases where the Clang type was written as a typedef of a
// block type, that typedef will have a Swift function type
// representation. This code will then break down the imported type
// alias and produce a function type with block representation.
auto requiredFunctionTypeRepr = FunctionTypeRepresentation::Swift;
if (importKind == ImportTypeKind::ObjCCollectionElement) {
requiredFunctionTypeRepr = FunctionTypeRepresentation::Block;
}

auto fTy = importedType->castTo<FunctionType>();
FunctionType::ExtInfo einfo = fTy->getExtInfo();
if (einfo.getRepresentation() != FunctionTypeRepresentation::Swift) {
einfo = einfo.withRepresentation(FunctionTypeRepresentation::Swift);
if (einfo.getRepresentation() != requiredFunctionTypeRepr) {
einfo = einfo.withRepresentation(requiredFunctionTypeRepr);
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Since @convention(block) is the default, it seems simple to just change the condition here: canBridgeTypes(importKind) && importKind != ImportTypeKind::ObjCGenericArgument.

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This is the rathole I went down before, because the way in which we pass down the desired "bridgeability" of the imported type doesn't account for blocks, which are bridgeable in some positions but not others. The problem with simply trying to exclude ObjCGenericArgument here is that the mappedType we get here has already been given the Swift function type representation (because we're importing a typedef with "full bridgeability"), and we no longer have the block type around.

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Ah, typedefs. In that case, can you update the comment above?

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Yeah.

importedType = fTy->withExtInfo(einfo);
}
}
Expand Down
4 changes: 2 additions & 2 deletions lib/ClangImporter/ImporterImpl.h
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Expand Up @@ -108,8 +108,8 @@ enum class ImportTypeKind {
/// \brief Import the type of a literal value.
Value,

/// \brief Import the type of a literal value that can be bridged.
BridgedValue,
/// \brief Import the type of an Objective-C generic argument.
ObjCCollectionElement,

/// \brief Import the declared type of a variable.
Variable,
Expand Down
4 changes: 4 additions & 0 deletions test/ClangImporter/objc_bridging_generics.swift
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Expand Up @@ -414,3 +414,7 @@ func testHashableGenerics(
let _: Int = insufficient.foo // expected-error{{cannot convert value of type 'Set<AnyHashable>' to specified type 'Int'}}
let _: Int = extra.foo // expected-error{{cannot convert value of type 'Set<ElementConcrete>' to specified type 'Int'}}
}

func testGenericsWithTypedefBlocks(hba: HasBlockArray) {
let _: Int = hba.blockArray() // expected-error{{type '[@convention(block) () -> Void]'}}
}
8 changes: 8 additions & 0 deletions test/ClangImporter/objc_ir.swift
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Expand Up @@ -13,6 +13,7 @@ import Foundation
import objc_ext
import TestProtocols
import ObjCIRExtras
import objc_generics

// CHECK: @"\01L_selector_data(method:withFloat:)" = private global [18 x i8] c"method:withFloat:\00"
// CHECK: @"\01L_selector_data(method:withDouble:)" = private global [19 x i8] c"method:withDouble:\00"
Expand Down Expand Up @@ -344,6 +345,13 @@ func testConstrGenericCompatibilityAliasMangling(constr_generic_obj: SwiftConstr
// CHECK: call void @llvm.dbg.declare(metadata %TSo26SwiftConstrGenericNameTestCySo8NSNumberCG** {{%.+}}, metadata ![[SWIFT_CONSTR_GENERIC_NAME_ALIAS_VAR:[0-9]+]], metadata !DIExpression())
}

// CHECK-LABEL: S7objc_ir22testBlocksWithGenerics3hbaypSo13HasBlockArrayC_tF
func testBlocksWithGenerics(hba: HasBlockArray) -> Any {
// CHECK: {{call swiftcc.*SSo13HasBlockArrayC05blockC0SayyyXBGyFTcTO}}
let _ = hba.blockPointerType()
return hba.blockArray
}

// CHECK: linkonce_odr hidden {{.*}} @"$SSo1BC3intABSgs5Int32V_tcfcTO"
// CHECK: load i8*, i8** @"\01L_selector(initWithInt:)"
// CHECK: call [[OPAQUE:%.*]]* bitcast (void ()* @objc_msgSend
Expand Down
7 changes: 7 additions & 0 deletions test/Inputs/clang-importer-sdk/usr/include/objc_generics.h
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Expand Up @@ -113,3 +113,10 @@ typedef id <Fungible> FungibleObject;

@interface Third : Second<Third *>
@end

typedef void (^ _Nonnull BlockPointerType)(void);

@interface HasBlockArray : NSObject
- (NSArray<BlockPointerType> * _Nonnull)blockArray;
- (BlockPointerType)blockPointerType;
@end