[interop][SwiftToCxx] use vtable/thunk to dispatch class subscript getters

Author: hyp

lib/PrintAsClang/DeclAndTypePrinter.cpp

@@ -1013,7 +1013,7 @@ class DeclAndTypePrinter::Implementation
           declPrinter.printCxxSubscriptAccessorMethod(
               typeDeclContext, accessor, funcABI->getSignature(),
               funcABI->getSymbolName(), resultTy,
-              /*isDefinition=*/false);
+              /*isDefinition=*/false, dispatchInfo);
         else
           declPrinter.printCxxPropertyAccessorMethod(
               typeDeclContext, accessor, funcABI->getSignature(),
@@ -1037,7 +1037,8 @@ class DeclAndTypePrinter::Implementation
         if (SD)
           defPrinter.printCxxSubscriptAccessorMethod(
               typeDeclContext, accessor, funcABI->getSignature(),
-              funcABI->getSymbolName(), resultTy, /*isDefinition=*/true);
+              funcABI->getSymbolName(), resultTy, /*isDefinition=*/true,
+              dispatchInfo);
         else
           defPrinter.printCxxPropertyAccessorMethod(
               typeDeclContext, accessor, funcABI->getSignature(),

lib/PrintAsClang/PrintClangFunction.cpp

@@ -1459,7 +1459,8 @@ void DeclAndTypeClangFunctionPrinter::printCxxPropertyAccessorMethod(
 void DeclAndTypeClangFunctionPrinter::printCxxSubscriptAccessorMethod(
     const NominalTypeDecl *typeDeclContext, const AccessorDecl *accessor,
     const LoweredFunctionSignature &signature, StringRef swiftSymbolName,
-    Type resultTy, bool isDefinition) {
+    Type resultTy, bool isDefinition,
+    Optional<IRABIDetailsProvider::MethodDispatchInfo> dispatchInfo) {
   assert(accessor->isGetter());
   FunctionSignatureModifiers modifiers;
   if (isDefinition)
@@ -1476,9 +1477,10 @@ void DeclAndTypeClangFunctionPrinter::printCxxSubscriptAccessorMethod(
   }
   os << " {\n";
   // FIXME: should it be objTy for resultTy?
-  printCxxThunkBody(accessor, signature, swiftSymbolName, typeDeclContext,
-                    accessor->getModuleContext(), resultTy,
-                    accessor->getParameters());
+  printCxxThunkBody(
+      accessor, signature, swiftSymbolName, typeDeclContext,
+      accessor->getModuleContext(), resultTy, accessor->getParameters(),
+      /*hasThrows=*/false, nullptr, /*isStatic=*/false, dispatchInfo);
   os << "  }\n";
 }
 

lib/PrintAsClang/PrintClangFunction.h

@@ -135,7 +135,8 @@ class DeclAndTypeClangFunctionPrinter {
   void printCxxSubscriptAccessorMethod(
       const NominalTypeDecl *typeDeclContext, const AccessorDecl *accessor,
       const LoweredFunctionSignature &signature, StringRef swiftSymbolName,
-      Type resultTy, bool isDefinition);
+      Type resultTy, bool isDefinition,
+      Optional<IRABIDetailsProvider::MethodDispatchInfo> dispatchInfo);
 
   /// Print Swift type as C/C++ type, as the return type of a C/C++ function.
   ClangRepresentation

test/Interop/SwiftToCxx/class/swift-class-virtual-method-dispatch-execution.cpp

@@ -151,5 +151,16 @@ int main() {
     x = derivedDerived.getComputedPropInDerivedDerived();
     assert(x == 11);
   }
+
+  {
+    swift::Int x;
+    x = base[23];
+    assert(x == 23);
+
+    x = derivedAsBase[23];
+    assert(x == 46);
+    x = derivedDerivedAsBase[-11];
+    assert(x == -22);
+  }
   return 0;
 }

test/Interop/SwiftToCxx/class/swift-class-virtual-method-dispatch.swift

@@ -32,6 +32,10 @@ public class BaseClass {
       }
   }
   public var storedProp: Int = 0
+
+  public subscript(_ i: Int) -> Int {
+    return i
+  }
 }
 
 public class DerivedClass: BaseClass {
@@ -67,6 +71,10 @@ public class DerivedClass: BaseClass {
       super.storedProp = newValue
     }
   }
+
+  override public subscript(_ i: Int) -> Int {
+    return i * 2
+  }
 }
 
 public final class DerivedDerivedClass: DerivedClass {
@@ -166,6 +174,13 @@ public func returnDerivedDerivedClass() -> DerivedDerivedClass {
 // CHECK-NEXT:   return (* fptr_)(value, ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
 // CHECK-NEXT:   }
 
+// CHECK:         swift::Int BaseClass::operator [](swift::Int i) const
+// CHECK-NEXT:    void ***selfPtr_ = reinterpret_cast<void ***>( ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
+// CHECK-NEXT:    void **vtable_ = *selfPtr_;
+// CHECK-NEXT:    using FType = decltype(_impl::$s5Class04BaseA0CyS2icig);
+// CHECK-NEXT:    FType *fptr_ = reinterpret_cast<FType *>(*(vtable_ + [[#VM1 + 9]]));
+// CHECK-NEXT:    return (* fptr_)(i, ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
+
 // CHECK:        void DerivedClass::virtualMethod() {
 // CHECK-NEXT:   void ***selfPtr_ = reinterpret_cast<void ***>( ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
 // CHECK-NEXT:   void **vtable_ = *selfPtr_;
@@ -186,7 +201,7 @@ public func returnDerivedDerivedClass() -> DerivedDerivedClass {
 // CHECK-NEXT:   void ***selfPtr_ = reinterpret_cast<void ***>( ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
 // CHECK-NEXT:   void **vtable_ = *selfPtr_;
 // CHECK-NEXT:   using FType = decltype(_impl::$s5Class07DerivedA0C015virtualMethodInB0yAA04BaseA0CAFF);
-// CHECK-NEXT:   FType *fptr_ = reinterpret_cast<FType *>(*(vtable_ + [[#VM1 + 9]]));
+// CHECK-NEXT:   FType *fptr_ = reinterpret_cast<FType *>(*(vtable_ + [[#VM1 + 10]]));
 // CHECK-NEXT:     return _impl::_impl_BaseClass::makeRetained((* fptr_)(::swift::_impl::_impl_RefCountedClass::getOpaquePointer(x), ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this)));
 // CHECK-NEXT:     }
 
@@ -230,6 +245,13 @@ public func returnDerivedDerivedClass() -> DerivedDerivedClass {
 // CHECK-NEXT:     return (* fptr_)(newValue, ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
 // CHECK-NEXT:     }
 
+// CHECK:         swift::Int DerivedClass::operator [](swift::Int i) const
+// CHECK-NEXT:    void ***selfPtr_ = reinterpret_cast<void ***>( ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
+// CHECK-NEXT:    void **vtable_ = *selfPtr_;
+// CHECK-NEXT:    using FType = decltype(_impl::$s5Class07DerivedA0CyS2icig);
+// CHECK-NEXT:    FType *fptr_ = reinterpret_cast<FType *>(*(vtable_ + [[#VM1 + 9]]));
+// CHECK-NEXT:    return (* fptr_)(i, ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
+
 // CHECK:        void DerivedDerivedClass::virtualMethod() {
 // CHECK-NEXT:     return _impl::$s5Class07DerivedbA0C13virtualMethodyyF(::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
 // CHECK-NEXT:     }

test/Interop/SwiftToCxx/class/swift-resilient-class-virtual-method-dispatch.swift

@@ -39,6 +39,9 @@
 // CHECK:         void BaseClass::setStoredProp(swift::Int value) {
 // CHECK-NEXT:    _impl::$s5Class04BaseA0C10storedPropSivsTj(value, ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
 
+// CHECK:           swift::Int BaseClass::operator [](swift::Int i) const
+// CHECK-NEXT:      return _impl::$s5Class04BaseA0CyS2icigTj(i, ::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
+
 // CHECK:        void DerivedClass::virtualMethod() {
 // CHECK-NEXT:   return _impl::$s5Class04BaseA0C13virtualMethodyyFTj(::swift::_impl::_impl_RefCountedClass::getOpaquePointer(*this));
 // CHECK-NEXT:   }