SILGen: Fix assign_by_wrapper of @objc dynamic properties

Insert a thunk. Objc method calls might need bridging.

rdar://60038084

Author: aschwaighofer

lib/SILGen/SILGenLValue.cpp

@@ -1448,11 +1448,16 @@ namespace {
             SGF.getConstantInfo(SGF.getTypeExpansionContext(), setter);
         SILValue setterFRef;
         if (setter.hasDecl() && setter.getDecl()->isObjCDynamic()) {
-          auto methodTy = SILType::getPrimitiveObjectType(
-              SGF.SGM.Types.getConstantFunctionType(SGF.getTypeExpansionContext(),
-                                                    setter));
-          setterFRef = SGF.B.createObjCMethod(
-              loc, base.getValue(), setter, methodTy);
+          // Emit a thunk we might have to bridge arguments.
+          auto foreignSetterThunk = setter.asForeign(false);
+          setterFRef =
+              SGF.emitDynamicMethodRef(
+                     loc, foreignSetterThunk,
+                     SGF.SGM.Types
+                         .getConstantInfo(SGF.getTypeExpansionContext(), foreignSetterThunk)
+                         .SILFnType)
+                  .getValue();
+
         } else
           setterFRef = SGF.emitGlobalFunctionRef(loc, setter, setterInfo);
         CanSILFunctionType setterTy = setterFRef->getType().castTo<SILFunctionType>();

test/SILGen/objc_properties.swift

@@ -270,13 +270,36 @@ public struct SomeWrapper {
   }
 }
 
+@propertyWrapper struct W<Value> {
+  var wrappedValue: Value {
+    get { return x }
+    set {  }
+  }
+
+  var x: Value
+
+  init(wrappedValue: Value) {
+    x = wrappedValue
+  }
+}
+
 class SomeWrapperTests {
   @objc @SomeWrapper dynamic var someWrapper: Int = 0
 // CHECK-LABEL: sil hidden [ossa] @$s15objc_properties16SomeWrapperTestsC14testAssignmentyyF
-// CHECK: [[M:%.*]] = objc_method %0 : $SomeWrapperTests, #SomeWrapperTests.someWrapper!setter.foreign
-// CHECK: [[C:%.*]] = partial_apply [callee_guaranteed] [[M]]({{.*}}) : $@convention(objc_method)
+// CHECK:  [[M:%.*]] = function_ref @$s15objc_properties16SomeWrapperTestsC04someD0SivsTD
+// CHECK:  [[C:%.*]] = partial_apply [callee_guaranteed] [[M]]({{.*}})
 // CHECK: assign_by_wrapper {{%.*}}: $Int to {{%.*}} : $*SomeWrapper, init {{.*}} : $@callee_guaranteed (Int) -> SomeWrapper, set [[C]] : $@callee_guaranteed (Int) -> ()
   func testAssignment() {
     someWrapper = 1000
   }
+
+  @W @objc dynamic var s: String? = nil
+// CHECK-LABEL: sil hidden [ossa] @$s15objc_properties16SomeWrapperTestsC16testBridgedValueyySSF
+// CHECK: [[M:%.*]] = function_ref @$s15objc_properties16SomeWrapperTestsC1sSSSgvsTD
+// CHECK: [[C:%.*]] = partial_apply [callee_guaranteed] [[M]](
+// CHECK:  assign_by_wrapper {{.*}} : $Optional<String> to {{.*}} : $*W<Optional<String>>, init {{.*}} : $@callee_guaranteed (@owned Optional<String>) -> @owned W<Optional<String>>, set [[C]] : $@callee_guaranteed (@owned Optional<String>) -> ()
+  // Let's not crash.
+  func testBridgedValue(_ s: String) {
+    self.s = s
+  }
 }