Merge pull request #59149 from WANGJIEKE/cxx-interop-inout-param

[cxx interop] Export inout params as C++ reference

Author: hyp

lib/PrintAsClang/DeclAndTypePrinter.cpp

@@ -889,6 +889,10 @@ class DeclAndTypePrinter::Implementation
     if (params->size()) {
       size_t index = 1;
       interleaveComma(*params, os, [&](const ParamDecl *param) {
+        if (param->isInOut()) {
+          os << "&";
+        }
+
         if (param->hasName()) {
           ClangSyntaxPrinter(os).printIdentifier(param->getName().str());
         } else {

lib/PrintAsClang/PrintClangFunction.cpp

@@ -102,12 +102,16 @@ void DeclAndTypeClangFunctionPrinter::printFunctionSignature(
                                       : OutputLanguageMode::Cxx;
   // FIXME: Might need a PrintMultiPartType here.
   auto print = [&, this](Type ty, Optional<OptionalTypeKind> optionalKind,
-                         StringRef name) {
+                         StringRef name, bool isInOutParam) {
     // FIXME: add support for noescape and PrintMultiPartType,
     // see DeclAndTypePrinter::print.
     CFunctionSignatureTypePrinter typePrinter(os, typeMapping, outputLang);
     typePrinter.visit(ty, optionalKind);
 
+    if (isInOutParam) {
+      os << (outputLang == OutputLanguageMode::Cxx ? " &" : " *");
+    }
+
     if (!name.empty()) {
       os << ' ';
       ClangSyntaxPrinter(os).printIdentifier(name);
@@ -142,7 +146,7 @@ void DeclAndTypeClangFunctionPrinter::printFunctionSignature(
         llvm::raw_string_ostream os(paramName);
         os << "_" << paramIndex;
       }
-      print(objTy, argKind, paramName);
+      print(objTy, argKind, paramName, param->isInOut());
       ++paramIndex;
     });
   } else if (kind == FunctionSignatureKind::CFunctionProto) {

test/Interop/SwiftToCxx/functions/swift-primitive-inout-functions-cxx-bridging.swift

@@ -0,0 +1,33 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend %s -typecheck -module-name Functions -clang-header-expose-public-decls -emit-clang-header-path %t/functions.h
+// RUN: %FileCheck %s < %t/functions.h
+
+// RUN: %check-interop-cxx-header-in-clang(%t/functions.h)
+
+// CHECK: SWIFT_EXTERN void $s9Functions8inOutIntyySizF(ptrdiff_t * x) SWIFT_NOEXCEPT SWIFT_CALL; // inOutInt(_:)
+// CHECK: SWIFT_EXTERN void $s9Functions11inOutTwoIntyySiz_SiztF(ptrdiff_t * x, ptrdiff_t * y) SWIFT_NOEXCEPT SWIFT_CALL; // inOutTwoInt(_:_:)
+// CHECK: SWIFT_EXTERN void $s9Functions13inOutTwoParamyySbz_SdztF(bool * x, double * y) SWIFT_NOEXCEPT SWIFT_CALL; // inOutTwoParam(_:_:)
+
+// CHECK:      inline void inOutInt(swift::Int & x) noexcept {
+// CHECK-NEXT:   return _impl::$s9Functions8inOutIntyySizF(&x);
+// CHECK-NEXT: }
+
+// CHECK:      inline void inOutTwoInt(swift::Int & x, swift::Int & y) noexcept {
+// CHECK-NEXT:   return _impl::$s9Functions11inOutTwoIntyySiz_SiztF(&x, &y);
+// CHECK-NEXT: }
+
+// CHECK:      inline void inOutTwoParam(bool & x, double & y) noexcept {
+// CHECK-NEXT:   return _impl::$s9Functions13inOutTwoParamyySbz_SdztF(&x, &y);
+// CHECK-NEXT: }
+
+public func inOutInt(_ x: inout Int) { x = Int() }
+
+public func inOutTwoInt(_ x: inout Int, _ y: inout Int) {
+    x += y
+    y -= 2 * x
+}
+
+public func inOutTwoParam(_ x: inout Bool, _ y: inout Double) {
+    y = 3.14
+    x = !x
+}

test/Interop/SwiftToCxx/functions/swift-primitive-inout-functions-execution.cpp

@@ -0,0 +1,42 @@
+// RUN: %empty-directory(%t)
+
+// RUN: %target-swift-frontend %S/swift-primitive-inout-functions-cxx-bridging.swift -typecheck -module-name Functions -clang-header-expose-public-decls -emit-clang-header-path %t/functions.h
+
+// RUN: %target-interop-build-clangxx -c %s -I %t -o %t/swift-functions-execution.o
+// RUN: %target-interop-build-swift %S/swift-primitive-inout-functions-cxx-bridging.swift -o %t/swift-functions-execution -Xlinker %t/swift-functions-execution.o -module-name Functions -Xfrontend -entry-point-function-name -Xfrontend swiftMain
+
+// RUN: %target-codesign %t/swift-functions-execution
+// RUN: %target-run %t/swift-functions-execution
+
+// REQUIRES: executable_test
+
+#include <cassert>
+#include "functions.h"
+
+#define VERIFY_INOUT_VALUE(FUNC, TYPENAME, INITIAL_VALUE, EXPECT_VALUE) \
+do { \
+    TYPENAME variable = INITIAL_VALUE; \
+    FUNC(variable); \
+    assert(variable == EXPECT_VALUE); \
+} while (false);
+
+int main() {
+    using namespace Functions;
+
+    VERIFY_INOUT_VALUE(inOutInt, swift::Int, swift::Int{1}, swift::Int{0});
+
+    {
+        swift::Int x{1}, y{2};
+        inOutTwoInt(x, y);
+        assert(x == swift::Int{3});
+        assert(y == swift::Int{-4});
+    }
+
+    {
+        bool x = false;
+        double y = 6.28;
+        inOutTwoParam(x, y);
+        assert(x);
+        assert(y == 3.14);
+    }
+}