[cxx-interop] Add support for templated member functions.

Essentially applying the same change as for supporting templated
constructors.

lib/Sema/CSApply.cpp

@@ -115,10 +115,12 @@ static ConcreteDeclRef generateDeclRefForSpecializedCXXFunctionTemplate(
   auto newFnType = oldFnType->substGenericArgs(subst);
   // The constructor type is a function type as follows:
   //   (CType.Type) -> (Generic) -> CType
-  // But we only want the result of that function type because that is the
-  // function type with the generic params that need to be substituted:
+  // And a method's function type is as follows:
+  //   (inout CType) -> (Generic) -> Void
+  // In either case, we only want the result of that function type because that
+  // is the function type with the generic params that need to be substituted:
   //   (Generic) -> CType
-  if (isa<ConstructorDecl>(oldDecl))
+  if (isa<ConstructorDecl>(oldDecl) || oldDecl->isInstanceMember())
     newFnType = cast<FunctionType>(newFnType->getResult().getPointer());
   SmallVector<ParamDecl *, 4> newParams;
   unsigned i = 0;
@@ -159,6 +161,7 @@ static ConcreteDeclRef generateDeclRefForSpecializedCXXFunctionTemplate(
       /*Async=*/false, oldDecl->hasThrows(), newParamList,
       newFnType->getResult(), /*GenericParams=*/nullptr,
       oldDecl->getDeclContext(), specialized);
+  newFnDecl->setSelfAccessKind(cast<FuncDecl>(oldDecl)->getSelfAccessKind());
   return ConcreteDeclRef(newFnDecl);
 }
 

test/Interop/Cxx/templates/Inputs/member-templates.h

@@ -0,0 +1,31 @@
+struct HasMemberTemplates {
+  template <class T> T add(T a, T b) { return a + b; }
+
+  template <class T, class U> T addTwoTemplates(T a, U b) { return a + b; }
+
+  template <class T, class U> int addAll(int a, T b, U c) { return a + b + c; }
+
+  template <class T> T passThrough(T val) { return val; }
+
+  template <class T> T passThroughConst(const T val) { return val; }
+
+  template <class T> T passThroughOnConst(T val) const { return val; }
+
+  template <class T> T passThroughConstOnConst(const T val) const {
+    return val;
+  }
+
+  template <class T> void doNothingConstRef(const T &val) {}
+
+  template <class T> void make42Ref(T &val) {}
+};
+
+template <class T> struct TemplateClassWithMemberTemplates {
+  T value;
+
+  template <class U> void setValue(U val) { value = val; }
+
+  TemplateClassWithMemberTemplates(T val) : value(val) {}
+};
+
+using IntWrapper = TemplateClassWithMemberTemplates<int>;

test/Interop/Cxx/templates/Inputs/module.modulemap

@@ -61,3 +61,7 @@ module ClassTemplateWithTypedef {
 module ClassTemplateInNamespace {
   header "class-template-in-namespace.h"
 }
+
+module MemberTemplates {
+  header "member-templates.h"
+}

test/Interop/Cxx/templates/member-templates-module-interface.swift

@@ -0,0 +1,21 @@
+// RUN: %target-swift-ide-test -print-module -module-to-print=MemberTemplates -I %S/Inputs -source-filename=x -enable-cxx-interop | %FileCheck %s
+
+// CHECK: struct HasMemberTemplates {
+// CHECK:   mutating func add<T>(_ a: T, _ b: T) -> T
+// CHECK:   mutating func addTwoTemplates<T, U>(_ a: T, _ b: U) -> T
+// CHECK:   mutating func addAll<T, U>(_ a: Int32, _ b: T, _ c: U) -> Int32
+// CHECK:   mutating func passThrough<T>(_ val: T) -> T
+// CHECK:   mutating func passThroughConst<T>(_ val: T) -> T
+// CHECK:   mutating func passThroughOnConst<T>(_ val: T) -> T
+// CHECK:   mutating func passThroughConstOnConst<T>(_ val: T) -> T
+// CHECK:   mutating func doNothingConstRef<T>(_ val: UnsafePointer<T>)
+// CHECK:   mutating func make42Ref<T>(_ val: UnsafeMutablePointer<T>)
+// CHECK: }
+
+// CHECK: struct __CxxTemplateInst32TemplateClassWithMemberTemplatesIiE {
+// CHECK:   var value: Int32
+// CHECK:   init(_ val: Int32)
+// CHECK:   mutating func setValue<U>(_ val: U)
+// CHECK: }
+
+// CHECK: typealias IntWrapper = __CxxTemplateInst32TemplateClassWithMemberTemplatesIiE

test/Interop/Cxx/templates/member-templates-silgen.swift

@@ -0,0 +1,50 @@
+// RUN: %target-swift-emit-sil %s -I %S/Inputs -enable-cxx-interop | %FileCheck %s
+
+// We can't yet call member functions correctly on Windows (SR-13129).
+// XFAIL: OS=windows-msvc
+// REQUIRES: fixing-after-30630
+
+import MemberTemplates
+
+// CHECK-LABEL: sil hidden @$s4main9basicTestyyF : $@convention(thin) () -> ()
+
+// CHECK: [[ADD:%.*]] = function_ref @_ZN18HasMemberTemplates3addIiEET_S1_S1_ : $@convention(c) (Int32, Int32, @inout HasMemberTemplates) -> Int32
+// CHECK: apply [[ADD]]({{.*}}) : $@convention(c) (Int32, Int32, @inout HasMemberTemplates) -> Int32
+
+// CHECK: [[ADD_TWO_TEMPLATES:%.*]] = function_ref @_ZN18HasMemberTemplates15addTwoTemplatesIiiEET_S1_T0_ : $@convention(c) (Int32, Int32, @inout HasMemberTemplates) -> Int32 // user: %26
+// CHECK: apply [[ADD_TWO_TEMPLATES]]({{.*}}) : $@convention(c) (Int32, Int32, @inout HasMemberTemplates) -> Int32
+
+// CHECK: [[ADD_ALL:%.*]] = function_ref @_ZN18HasMemberTemplates6addAllIiiEEiiT_T0_ : $@convention(c) (Int32, Int32, Int32, @inout HasMemberTemplates) -> Int32 // user: %39
+// CHECK: apply [[ADD_ALL]]({{.*}}) : $@convention(c) (Int32, Int32, Int32, @inout HasMemberTemplates) -> Int32
+
+// CHECK: [[DO_NOTHING:%.*]] = function_ref @_ZN18HasMemberTemplates17doNothingConstRefIiEEvRKT_ : $@convention(c) (UnsafePointer<Int32>, @inout HasMemberTemplates) -> () // user: %48
+// CHECK: apply [[DO_NOTHING]]({{.*}}) : $@convention(c) (UnsafePointer<Int32>, @inout HasMemberTemplates) -> ()
+
+// CHECK-LABEL: end sil function '$s4main9basicTestyyF'
+func basicTest() {
+  var i: Int32 = 0
+  var obj = HasMemberTemplates()
+  obj.add(i, i)
+  obj.addTwoTemplates(i, i)
+  obj.addAll(i, i, i)
+  obj.doNothingConstRef(&i)
+}
+
+// CHECK-LABEL: sil hidden_external [clang HasMemberTemplates._ZN18HasMemberTemplates3addIiEET_S1_S1_] @_ZN18HasMemberTemplates3addIiEET_S1_S1_ : $@convention(c) (Int32, Int32, @inout HasMemberTemplates) -> Int32
+
+// CHECK-LABEL: sil hidden_external [clang HasMemberTemplates._ZN18HasMemberTemplates15addTwoTemplatesIiiEET_S1_T0_] @_ZN18HasMemberTemplates15addTwoTemplatesIiiEET_S1_T0_ : $@convention(c) (Int32, Int32, @inout HasMemberTemplates) -> Int32
+
+// CHECK-LABEL: sil hidden_external [clang HasMemberTemplates._ZN18HasMemberTemplates6addAllIiiEEiiT_T0_] @_ZN18HasMemberTemplates6addAllIiiEEiiT_T0_ : $@convention(c) (Int32, Int32, Int32, @inout HasMemberTemplates) -> Int32
+
+// CHECK-LABEL: sil hidden_external [clang HasMemberTemplates._ZN18HasMemberTemplates17doNothingConstRefIiEEvRKT_] @_ZN18HasMemberTemplates17doNothingConstRefIiEEvRKT_ : $@convention(c) (UnsafePointer<Int32>, @inout HasMemberTemplates) -> ()
+
+// CHECK-LABEL: sil hidden @$s4main12testSetValueyyF : $@convention(thin) () -> ()
+
+// CHECK: [[SET_VALUE:%.*]] = function_ref @_ZN32TemplateClassWithMemberTemplatesIiE8setValueIlEEvT_ : $@convention(c) (Int, @inout __CxxTemplateInst32TemplateClassWithMemberTemplatesIiE) -> ()
+// CHECK: apply [[SET_VALUE]]({{.*}}) : $@convention(c) (Int, @inout __CxxTemplateInst32TemplateClassWithMemberTemplatesIiE) -> ()
+
+// CHECK-LABEL: end sil function '$s4main12testSetValueyyF'
+func testSetValue() {
+  var w = IntWrapper(11)
+  w.setValue(42)
+}

test/Interop/Cxx/templates/member-templates.swift

@@ -0,0 +1,26 @@
+// RUN: %target-run-simple-swift(-I %S/Inputs -Xfrontend -enable-cxx-interop)
+//
+// REQUIRES: executable_test
+//
+// We can't yet call member functions correctly on Windows (SR-13129).
+// XFAIL: OS=windows-msvc
+// REQUIRES: fixing-after-30630
+
+import MemberTemplates
+import StdlibUnittest
+
+var TemplatesTestSuite = TestSuite("Member Templates")
+
+TemplatesTestSuite.test("Set value - IntWrapper") {
+  var w = IntWrapper(11)
+  w.setValue(42)
+  expectEqual(w.value, 42)
+}
+
+TemplatesTestSuite.test("Templated Add") {
+  var h = HasMemberTemplates()
+  expectEqual(h.add(2, 1), 3)
+  expectEqual(h.addTwoTemplates(2, 1), 3)
+}
+
+runAllTests()