[cxx-interop] add additional tests for calling base methods on FRT

Author: hyp

test/Interop/Cxx/foreign-reference/Inputs/function-inheritance.h

@@ -0,0 +1,56 @@
+#pragma once
+
+#define FRT                                       \
+  __attribute__((swift_attr("import_reference"))) \
+  __attribute__((swift_attr("retain:immortal")))  \
+  __attribute__((swift_attr("release:immortal")))
+
+int &getCopyCounter() {
+    static int copyCounter = 0;
+    return copyCounter;
+}
+
+class CopyTrackedBaseClass {
+public:
+    CopyTrackedBaseClass(int x) : x(x) {}
+    CopyTrackedBaseClass(const CopyTrackedBaseClass &other) : x(other.x) {
+        ++getCopyCounter();
+    }
+
+    int getX() const {
+        return x;
+    }
+private:
+    int x;
+} FRT;
+
+class CopyTrackedDerivedClass: public CopyTrackedBaseClass {
+public:
+    CopyTrackedDerivedClass(int x) : CopyTrackedBaseClass(x) {}
+
+    int getDerivedX() const {
+        return getX();
+    }
+} FRT;
+
+CopyTrackedDerivedClass *makeCopyTrackedDerivedClass(int x) {
+    return new CopyTrackedDerivedClass(x);
+}
+
+class NonEmptyBase {
+public:
+    int getY() const {
+        return y;
+    }
+private:
+    int y = 11;
+} FRT;
+
+class CopyTrackedDerivedDerivedClass: public NonEmptyBase, public CopyTrackedDerivedClass {
+public:
+    CopyTrackedDerivedDerivedClass(int x) : CopyTrackedDerivedClass(x) {}
+} FRT;
+
+CopyTrackedDerivedDerivedClass *makeCopyTrackedDerivedDerivedClass(int x) {
+    return new CopyTrackedDerivedDerivedClass(x);
+}

test/Interop/Cxx/foreign-reference/Inputs/module.modulemap

@@ -32,3 +32,8 @@ module MemberLayout {
   header "member-layout.h"
   requires cplusplus
 }
+
+module FunctionInheritance {
+  header "function-inheritance.h"
+  requires cplusplus
+}

test/Interop/Cxx/foreign-reference/function-inheritance-irgen.swift

@@ -0,0 +1,15 @@
+// RUN: %target-swift-emit-irgen -I %S/Inputs -enable-experimental-cxx-interop %s -validate-tbd-against-ir=none -Xcc -fignore-exceptions | %FileCheck %s
+
+import FunctionInheritance
+
+func testGetX() -> CInt {
+    let derivedDerived = makeCopyTrackedDerivedDerivedClass(42)!
+    return derivedDerived.getX()
+}
+
+let _ = testGetX()
+
+
+// CHECK: define {{.*}}linkonce_odr{{.*}} i32 @{{.*}}__synthesizedBaseCall___synthesizedBaseCall_{{.*}}(ptr {{.*}} %[[THIS_PTR:.*]])
+// CHECK: %[[ADD_PTR:.*]] = getelementptr inbounds i8, ptr %{{.*}}, i64 4
+// CHECK: call noundef i32 @{{.*}}(ptr {{.*}} %[[ADD_PTR]])

test/Interop/Cxx/foreign-reference/function-inheritance.swift

@@ -0,0 +1,25 @@
+// RUN: %target-run-simple-swift(-I %S/Inputs/ -Xfrontend -enable-experimental-cxx-interop)
+//
+// REQUIRES: executable_test
+
+import StdlibUnittest
+import FunctionInheritance
+
+var FunctionsTestSuite = TestSuite("Calling functions in base foreign reference classes")
+
+FunctionsTestSuite.test("base member FRT calls do not require copying") {
+  let derived = makeCopyTrackedDerivedClass(42)!
+  var copyCounter = getCopyCounter().pointee
+  expectEqual(derived.getX(), 42)
+  expectEqual(copyCounter, getCopyCounter().pointee)
+  expectEqual(derived.getDerivedX(), 42)
+  expectEqual(copyCounter, getCopyCounter().pointee)
+
+  let derivedDerived = makeCopyTrackedDerivedDerivedClass(-5)!
+  copyCounter = getCopyCounter().pointee
+  expectEqual(derivedDerived.getX(), -5)
+  expectEqual(derivedDerived.getY(), 11)
+  expectEqual(copyCounter, getCopyCounter().pointee)
+}
+
+runAllTests()