Merge pull request #59292 from WANGJIEKE/cxx-interop-not-expose-async-and-transparent-func

[cxx-interop] Don't expose async or @_alwaysEmitIntoClient functions

Author: hyp

lib/PrintAsClang/DeclAndTypePrinter.cpp

@@ -1097,6 +1097,13 @@ class DeclAndTypePrinter::Implementation
 
   void visitFuncDecl(FuncDecl *FD) {
     if (outputLang == OutputLanguageMode::Cxx) {
+      // Don't expose async functions or @_alwaysEmitIntoClient functions
+      // because they're currently unsupported
+      if (FD->hasAsync() ||
+          FD->getAttrs().hasAttribute<AlwaysEmitIntoClientAttr>()) {
+        return;
+      }
+
       // Emit the underlying C signature that matches the Swift ABI
       // in the generated C++ implementation prologue for the module.
       std::string cFuncDecl;

test/Interop/SwiftToCxx/functions/swift-no-expose-unsupported-alwaysEmitInClient-func.swift

@@ -0,0 +1,21 @@
+// 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-NOT: SWIFT_EXTERN bool $s9Functions24alwaysEmitIntoClientFuncyS2bF(bool x) SWIFT_NOEXCEPT SWIFT_CALL; // alwaysEmitIntoClientFunc(_:)
+
+// CHECK:       namespace Functions {
+// CHECK-EMPTY:
+// CHECK-EMPTY:
+// CHECK-EMPTY:
+// CHECK-EMPTY:
+// CHECK-NEXT:  } // namespace Functions
+
+// CHECK-NOT: inline bool alwaysEmitIntoClientFunc(bool x) noexcept SWIFT_WARN_UNUSED_RESULT {
+// CHECK-NOT:   return _impl::$s9Functions24alwaysEmitIntoClientFuncyS2bF(x);
+// CHECK-NOT: }
+
+@_alwaysEmitIntoClient
+public func alwaysEmitIntoClientFunc(_ x: Bool) -> Bool { return !x }

test/Interop/SwiftToCxx/functions/swift-no-expose-unsupported-async-func.swift

@@ -0,0 +1,22 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend %s -typecheck -module-name Functions -disable-availability-checking -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-NOT: SWIFT_EXTERN double $s9Functions9asyncFuncyS2dYaF(double x) SWIFT_NOEXCEPT SWIFT_CALL; // asyncFunc(_:)
+
+// CHECK:       namespace Functions {
+// CHECK-EMPTY:
+// CHECK-EMPTY:
+// CHECK-EMPTY:
+// CHECK-EMPTY:
+// CHECK-NEXT:  } // namespace Functions
+
+// CHECK-NOT: inline double asyncFunc(double x) noexcept SWIFT_WARN_UNUSED_RESULT {
+// CHECK-NOT:   return _impl::$s9Functions9asyncFuncyS2dYaF(x);
+// CHECK-NOT: }
+
+// REQUIRES: concurrency
+
+public func asyncFunc(_ x: Double) async -> Double { return 2 * x }

test/Interop/SwiftToCxx/functions/swift-transparent-functions-cxx-bridging.swift

@@ -0,0 +1,14 @@
+// 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 ptrdiff_t $s9Functions24transparentPrimitiveFuncyS2iF(ptrdiff_t x) SWIFT_NOEXCEPT SWIFT_CALL; // transparentPrimitiveFunc(_:)
+
+// CHECK:      inline swift::Int transparentPrimitiveFunc(swift::Int x) noexcept SWIFT_WARN_UNUSED_RESULT {
+// CHECK-NEXT:   return _impl::$s9Functions24transparentPrimitiveFuncyS2iF(x);
+// CHECK-NEXT: }
+
+@_transparent
+public func transparentPrimitiveFunc(_ x: Int) -> Int { return x * x }

test/Interop/SwiftToCxx/functions/swift-transparent-functions-execution.cpp

@@ -0,0 +1,22 @@
+// RUN: %empty-directory(%t)
+
+// RUN: %target-swift-frontend %S/swift-transparent-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-transparent-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"
+
+int main() {
+    using namespace Functions;
+    
+    assert(transparentPrimitiveFunc(12) == 144);
+
+    return 0;
+}