Fix crash when emitting force-unwrap-and-call expression for optional ObjC methods

lib/SILGen/SILGenApply.cpp

@@ -1595,6 +1595,39 @@ class SILGenApply : public Lowering::ExprVisitor<SILGenApply> {
     return std::move(*applyCallee);
   }
 
+  /// \returns true if the conversion is from an async function to
+  /// the same type but with a global actor added. For example this:
+  ///     () async -> ()  ==>  @MainActor () async -> ()
+  /// will return true. In all other cases, returns false.
+  static bool addsGlobalActorToAsyncFn(FunctionConversionExpr *fce) {
+    CanType oldTy = fce->getSubExpr()->getType()->getCanonicalType();
+    CanType newTy = fce->getType()->getCanonicalType();
+
+    if (auto oldFnTy = dyn_cast<AnyFunctionType>(oldTy)) {
+      if (auto newFnTy = dyn_cast<AnyFunctionType>(newTy)) {
+        // old type MUST be async
+        if (!oldFnTy->hasEffect(EffectKind::Async))
+          return false;
+
+        // old type MUST NOT have a global actor
+        if (oldFnTy->hasGlobalActor())
+          return false;
+
+        // new type MUST have a global actor
+        if (!newFnTy->hasGlobalActor())
+          return false;
+
+        // see if adding the global actor to the old type yields the new type.
+        auto globalActor = newFnTy->getGlobalActor();
+        auto addedActor = oldFnTy->getExtInfo().withGlobalActor(globalActor);
+
+        return oldFnTy->withExtInfo(addedActor) == newFnTy;
+      }
+    }
+
+    return false;
+  }
+
   /// Ignore parentheses and implicit conversions.
   static Expr *ignoreParensAndImpConversions(Expr *expr) {
     while (true) {
@@ -1608,7 +1641,16 @@ class SILGenApply : public Lowering::ExprVisitor<SILGenApply> {
       // works given that we check the result for certain forms.
       if (auto eval = dyn_cast<OptionalEvaluationExpr>(expr)) {
         if (auto inject = dyn_cast<InjectIntoOptionalExpr>(eval->getSubExpr())) {
-          if (auto bind = dyn_cast<BindOptionalExpr>(inject->getSubExpr())) {
+
+          auto nextSubExpr = inject->getSubExpr();
+
+          // skip over a specific, known no-op function conversion, if it exists
+          if (auto funcConv = dyn_cast<FunctionConversionExpr>(nextSubExpr)) {
+            if (addsGlobalActorToAsyncFn(funcConv))
+              nextSubExpr = funcConv->getSubExpr();
+          }
+
+          if (auto bind = dyn_cast<BindOptionalExpr>(nextSubExpr)) {
             if (bind->getDepth() == 0)
               return bind->getSubExpr();
           }

test/ClangImporter/objc_async.swift

@@ -397,3 +397,11 @@ extension SomeWrapper: Sendable where T: Sendable {}
     }
   }
 }
+
+// rdar://97646309 -- lookup and direct call of an optional global-actor constrained method would crash in SILGen
+@available(SwiftStdlib 5.5, *)
+extension CoffeeDelegate  {
+    @MainActor func test() async -> (NSObject?, NSObject, NSObject) {
+        return await self.icedMochaServiceGenerateMocha!(NSObject())
+    }
+}

test/Inputs/clang-importer-sdk/usr/include/ObjCConcurrency.h

@@ -319,4 +319,12 @@ SENDABLE id StructWithSendableContentsGetSendableComputed(struct StructWithSenda
 + (void)getAsCustomer:(void(^_Nonnull)(NSObject *device))completion;
 @end
 
+
+// rdar://97646309
+UI_ACTOR
+@protocol CoffeeDelegate <NSObject>
+@optional
+- (void)icedMochaService:(NSObject *)mochaService generateMochaWithCompletion:(void (^)(NSObject *_Nullable ingredient1, NSObject *ingredient2, NSObject *ingredient3))completionHandler;
+@end
+
 #pragma clang assume_nonnull end

test/SILGen/dynamic_lookup.swift

@@ -1,5 +1,8 @@
-// RUN: %target-swift-emit-silgen -module-name dynamic_lookup -enable-objc-interop -parse-as-library -disable-objc-attr-requires-foundation-module %s | %FileCheck %s
-// RUN: %target-swift-emit-silgen -module-name dynamic_lookup -enable-objc-interop -parse-as-library -disable-objc-attr-requires-foundation-module  %s | %FileCheck %s --check-prefix=GUARANTEED
+// RUN: %target-swift-emit-silgen -module-name dynamic_lookup -enable-objc-interop -parse-as-library -disable-objc-attr-requires-foundation-module -disable-availability-checking %s | %FileCheck %s
+// RUN: %target-swift-emit-silgen -module-name dynamic_lookup -enable-objc-interop -parse-as-library -disable-objc-attr-requires-foundation-module -disable-availability-checking  %s | %FileCheck %s --check-prefix=GUARANTEED
+
+// REQUIRES: objc_interop
+// REQUIRES: concurrency
 
 class X {
   @objc func f() { }
@@ -405,3 +408,25 @@ func testAnyObjectWithDefault(_ x: AnyObject) {
   // CHECK: apply [[METHOD]]([[DEFARG]], [[OPENEDX]])
   x.hasDefaultParam()
 }
+
+
+// rdar://97646309 -- lookup and direct call of an optional global-actor constrained method would crash in SILGen
+@MainActor
+@objc protocol OptionalMemberLookups {
+  @objc optional func generateMaybe() async
+}
+
+extension OptionalMemberLookups {
+  // CHECK-LABEL: sil hidden [ossa] @$s14dynamic_lookup21OptionalMemberLookupsPAAE19testForceDirectCallyyYaF
+  // CHECK:         [[SELF:%[0-9]+]] = copy_value {{.*}} : $Self
+  // CHECK:         [[METH:%[0-9]+]] = objc_method {{.*}} : $Self, #OptionalMemberLookups.generateMaybe!foreign : <Self where Self : OptionalMemberLookups> (Self) -> () async -> (), $@convention(objc_method) (@convention(block) () -> (), Self) -> ()
+  // CHECK:         = function_ref @$sIeyB_yt14dynamic_lookup21OptionalMemberLookupsRzlTz_ : $@convention(c) @pseudogeneric <τ_0_0 where τ_0_0 : OptionalMemberLookups> (@inout_aliasable @block_storage UnsafeContinuation<(), Never>) -> ()
+  // CHECK:         [[BLOCK:%[0-9]+]] = init_block_storage_header {{.*}} : $*@block_storage UnsafeContinuation<(), Never>
+  // CHECK:         = apply [[METH]]([[BLOCK]], [[SELF]]) : $@convention(objc_method) (@convention(block) () -> (), Self) -> ()
+  // CHECK:         await_async_continuation {{.*}} : $Builtin.RawUnsafeContinuation, resume bb1
+  // CHECK:         hop_to_executor {{.*}} : $MainActor
+  // CHECK:        } // end sil function '$s14dynamic_lookup21OptionalMemberLookupsPAAE19testForceDirectCallyyYaF'
+  func testForceDirectCall() async -> Void {
+    await self.generateMaybe!()
+  }
+}