[Clang importer] Don't bridge blocks to Swift functions in ObjC gener…

…ic args. While the compiler can bridge C block types to Swift function types, the Swift runtime cannot. Don't bridge block types to Swift function types in Objective-C generic arguments, so NSArray<some-block-type> will get imported as [@convention(block) (...) -> Whatever] rather than [(...) -> Whatever] Fixes rdar://problem/40879067 in a fairly narrow way; the Clang importer's approach to adjusting types based on context needs a cleanup, but this is the safe, localized fix suitable for 4.2.
DougGregor · Jun 15, 2018 · d529002 · d529002
1 parent e3d69d1
commit d529002
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Showing 5 changed files with 36 additions and 8 deletions.
diff --git a/lib/ClangImporter/ImportType.cpp b/lib/ClangImporter/ImportType.cpp
@@ -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::ObjCGenericArgument,
+                AllowNSUIntegerAsInt, Bridging, OTK_None);
             if (!importedTypeArg) {
               importedTypeArgs.clear();
               break;
@@ -1102,7 +1102,7 @@ static bool canBridgeTypes(ImportTypeKind importKind) {
   case ImportTypeKind::CFUnretainedOutParameter:
   case ImportTypeKind::Property:
   case ImportTypeKind::PropertyWithReferenceSemantics:
-  case ImportTypeKind::BridgedValue:
+  case ImportTypeKind::ObjCGenericArgument:
   case ImportTypeKind::Typedef:
     return true;
   }
@@ -1116,7 +1116,7 @@ static bool isCFAudited(ImportTypeKind importKind) {
   case ImportTypeKind::Abstract:
   case ImportTypeKind::Typedef:
   case ImportTypeKind::Value:
-  case ImportTypeKind::BridgedValue:
+  case ImportTypeKind::ObjCGenericArgument:
   case ImportTypeKind::Variable:
   case ImportTypeKind::Result:
   case ImportTypeKind::Pointee:
@@ -1287,10 +1287,19 @@ static ImportedType adjustTypeForConcreteImport(
   // we would prefer to instead use the default Swift convention.
   if (hint == ImportHint::Block) {
     if (canBridgeTypes(importKind)) {
+      // Determine the representation we need. For Objective-C generic
+      // arguments, we cannot bridge them to a block, so force a block
+      // representation even if our imported type thus far is a Swift
+      // function representation.
+      auto requiredFunctionTypeRepr = FunctionTypeRepresentation::Swift;
+      if (importKind == ImportTypeKind::ObjCGenericArgument) {
+        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);
         importedType = fTy->withExtInfo(einfo);
       }
     }

diff --git a/lib/ClangImporter/ImporterImpl.h b/lib/ClangImporter/ImporterImpl.h
@@ -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.
+  ObjCGenericArgument,
 
   /// \brief Import the declared type of a variable.
   Variable,

diff --git a/test/ClangImporter/objc_bridging_generics.swift b/test/ClangImporter/objc_bridging_generics.swift
@@ -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]'}}
+}
diff --git a/test/ClangImporter/objc_ir.swift b/test/ClangImporter/objc_ir.swift
@@ -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"
@@ -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

diff --git a/test/Inputs/clang-importer-sdk/usr/include/objc_generics.h b/test/Inputs/clang-importer-sdk/usr/include/objc_generics.h
@@ -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