Merge pull request #77261 from hjyamauchi/release/6.0

Cherrypick fixes for issue 74866 to release/6.0

Author: DougGregor

include/swift/AST/ASTBridging.h

@@ -80,6 +80,10 @@ class BridgedDeclBaseName {
   BridgedIdentifier Ident;
 
 public:
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedDeclBaseName() : Ident() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedDeclBaseName(swift::DeclBaseName baseName) : Ident(baseName.Ident) {}
 
@@ -106,6 +110,10 @@ class BridgedDeclNameRef {
   void *_Nonnull opaque;
 
 public:
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedDeclNameRef() : opaque() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedDeclNameRef(swift::DeclNameRef name) : opaque(name.getOpaqueValue()) {}
 
@@ -162,6 +170,10 @@ class BridgedASTContext {
   swift::ASTContext * _Nonnull Ctx;
 
 public:
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedASTContext() : Ctx() {}
+
 #ifdef USED_IN_CPP_SOURCE
   SWIFT_UNAVAILABLE("Use init(raw:) instead")
   BridgedASTContext(swift::ASTContext &ctx) : Ctx(&ctx) {}
@@ -317,6 +329,10 @@ class BridgedDiagnosticArgument {
   int64_t storage[3];
 
 public:
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedDiagnosticArgument() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedDiagnosticArgument(const swift::DiagnosticArgument &arg) {
     *reinterpret_cast<swift::DiagnosticArgument *>(&storage) = arg;
@@ -334,6 +350,10 @@ class BridgedDiagnosticFixIt {
   int64_t storage[7];
 
 public:
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedDiagnosticFixIt() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedDiagnosticFixIt(const swift::DiagnosticInfo::FixIt &fixit){
     *reinterpret_cast<swift::DiagnosticInfo::FixIt *>(&storage) = fixit;
@@ -1333,6 +1353,10 @@ class BridgedStmtConditionElement {
   void *_Nonnull Raw;
 
 public:
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedStmtConditionElement() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedStmtConditionElement(swift::StmtConditionElement elem)
       : Raw(elem.getOpaqueValue()) {}

include/swift/Basic/BasicBridging.h

@@ -23,6 +23,15 @@
 // Pure bridging mode does not permit including any C++/llvm/swift headers.
 // See also the comments for `BRIDGING_MODE` in the top-level CMakeLists.txt file.
 //
+//
+// Note: On Windows ARM64, how a C++ struct/class value type is
+// returned is sensitive to conditions including whether a
+// user-defined constructor exists, etc. See
+// https://learn.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions?view=msvc-170#return-values
+// So, if a C++ struct/class type is returned as a value between Swift
+// and C++, we need to be careful to match the return convention
+// matches between the non-USED_IN_CPP_SOURCE (Swift) side and the
+// USE_IN_CPP_SOURCE (C++) side.
 #include "swift/Basic/BridgedSwiftObject.h"
 #include "swift/Basic/Compiler.h"
 
@@ -228,6 +237,10 @@ class BridgedOwnedString {
   size_t Length;
 
 public:
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedOwnedString() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedOwnedString(const std::string &stringToCopy);
 

include/swift/Parse/ParseBridging.h

@@ -30,6 +30,10 @@ class BridgedLegacyParser {
   swift::Parser *_Nonnull const handle;
 
 public:
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedLegacyParser() : handle(nullptr) {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedLegacyParser(swift::Parser &P) : handle(&P) {}
 

include/swift/SIL/SILBridging.h

@@ -82,6 +82,10 @@ struct BridgedResultInfo {
   swift::TypeBase * _Nonnull type;
   BridgedResultConvention convention;
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedResultInfo() {}
+
 #ifdef USED_IN_CPP_SOURCE
   inline static BridgedResultConvention
   castToResultConvention(swift::ResultConvention convention) {
@@ -99,6 +103,10 @@ struct OptionalBridgedResultInfo {
   swift::TypeBase * _Nullable type = nullptr;
   BridgedResultConvention convention = BridgedResultConvention::Indirect;
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  OptionalBridgedResultInfo() {}
+
 #ifdef USED_IN_CPP_SOURCE
   OptionalBridgedResultInfo(std::optional<swift::SILResultInfo> resultInfo) {
     if (resultInfo) {
@@ -113,6 +121,10 @@ struct OptionalBridgedResultInfo {
 struct BridgedResultInfoArray {
   BridgedArrayRef resultInfoArray;
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedResultInfoArray() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedResultInfoArray(llvm::ArrayRef<swift::SILResultInfo> results)
     : resultInfoArray(results) {}
@@ -195,6 +207,10 @@ struct BridgedParameterInfo {
 struct BridgedParameterInfoArray {
   BridgedArrayRef parameterInfoArray;
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedParameterInfoArray() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedParameterInfoArray(llvm::ArrayRef<swift::SILParameterInfo> parameters)
     : parameterInfoArray(parameters) {}
@@ -213,6 +229,10 @@ struct BridgedParameterInfoArray {
 struct BridgedYieldInfoArray {
   BridgedArrayRef yieldInfoArray;
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedYieldInfoArray() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedYieldInfoArray(llvm::ArrayRef<swift::SILYieldInfo> yields)
     : yieldInfoArray(yields) {}
@@ -303,6 +323,10 @@ struct BridgedType {
   struct EnumElementIterator {
     uint64_t storage[4];
 
+    // Ensure that this struct value type will be indirectly returned on
+    // Windows ARM64
+    EnumElementIterator() {}
+
 #ifdef USED_IN_CPP_SOURCE
     EnumElementIterator(swift::EnumDecl::ElementRange::iterator i) {
       static_assert(sizeof(EnumElementIterator) >= sizeof(swift::EnumDecl::ElementRange::iterator));
@@ -316,6 +340,10 @@ struct BridgedType {
     SWIFT_IMPORT_UNSAFE BRIDGED_INLINE EnumElementIterator getNext() const;
   };
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedType() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedType(swift::SILType t) : opaqueValue(t.getOpaqueValue()) {}
 
@@ -674,6 +702,10 @@ struct BridgedSubstitutionMap {
 struct BridgedTypeArray {
   BridgedArrayRef typeArray;
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64,
+  BridgedTypeArray() : typeArray() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedTypeArray(llvm::ArrayRef<swift::Type> types) : typeArray(types) {}
 
@@ -694,6 +726,10 @@ struct BridgedTypeArray {
 struct BridgedSILTypeArray {
   BridgedArrayRef typeArray;
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedSILTypeArray() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedSILTypeArray(llvm::ArrayRef<swift::SILType> silTypes)
       : typeArray(silTypes) {}
@@ -712,6 +748,10 @@ struct BridgedSILTypeArray {
 struct BridgedLocation {
   uint64_t storage[3];
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  BridgedLocation() {}
+
 #ifdef USED_IN_CPP_SOURCE
   BridgedLocation(const swift::SILDebugLocation &loc) {
     *reinterpret_cast<swift::SILDebugLocation *>(&storage) = loc;
@@ -738,6 +778,10 @@ struct BridgedGenericSpecializationInformation {
 struct OptionalBridgedSILDebugVariable {
   uint64_t storage[16];
 
+  // Ensure that this struct value type will be indirectly returned on
+  // Windows ARM64
+  OptionalBridgedSILDebugVariable() {}
+
 #ifdef USED_IN_CPP_SOURCE
   using OptionalSILDebugVariable = std::optional<swift::SILDebugVariable>;
 

include/swift/SILOptimizer/OptimizerBridging.h

@@ -85,6 +85,10 @@ struct BridgedCalleeAnalysis {
   struct CalleeList {
     uint64_t storage[3];
 
+    // Ensure that this struct value type will be indirectly returned on
+    // Windows ARM64
+    CalleeList() {}
+
 #ifdef USED_IN_CPP_SOURCE
     CalleeList(swift::CalleeList list) {
       *reinterpret_cast<swift::CalleeList *>(&storage) = list;

lib/ClangImporter/ImportType.cpp

@@ -2204,10 +2204,11 @@ ImportedType ClangImporter::Implementation::importFunctionReturnType(
   // C++ operators +=, -=, *=, /= may return a reference to self. This is not
   // idiomatic in Swift, let's drop these return values.
   clang::OverloadedOperatorKind op = clangDecl->getOverloadedOperator();
-  if (op == clang::OverloadedOperatorKind::OO_PlusEqual ||
-      op == clang::OverloadedOperatorKind::OO_MinusEqual ||
-      op == clang::OverloadedOperatorKind::OO_StarEqual ||
-      op == clang::OverloadedOperatorKind::OO_SlashEqual)
+  if ((op == clang::OverloadedOperatorKind::OO_PlusEqual ||
+       op == clang::OverloadedOperatorKind::OO_MinusEqual ||
+       op == clang::OverloadedOperatorKind::OO_StarEqual ||
+       op == clang::OverloadedOperatorKind::OO_SlashEqual) &&
+      clangDecl->getReturnType()->isReferenceType())
     return {SwiftContext.getVoidType(), false};
 
   // Fix up optionality.

lib/IRGen/GenCall.cpp

@@ -358,7 +358,8 @@ static void addIndirectResultAttributes(IRGenModule &IGM,
                                         llvm::AttributeList &attrs,
                                         unsigned paramIndex, bool allowSRet,
                                         llvm::Type *storageType,
-                                        const TypeInfo &typeInfo) {
+                                        const TypeInfo &typeInfo,
+                                        bool useInReg = false) {
   llvm::AttrBuilder b(IGM.getLLVMContext());
   b.addAttribute(llvm::Attribute::NoAlias);
   // Bitwise takable value types are guaranteed not to capture
@@ -368,6 +369,8 @@ static void addIndirectResultAttributes(IRGenModule &IGM,
   if (allowSRet) {
     assert(storageType);
     b.addStructRetAttr(storageType);
+    if (useInReg)
+      b.addAttribute(llvm::Attribute::InReg);
   }
   attrs = attrs.addParamAttributes(IGM.getLLVMContext(), paramIndex, b);
 }
@@ -475,7 +478,7 @@ namespace {
 
   private:
     const TypeInfo &expand(SILParameterInfo param);
-    llvm::Type *addIndirectResult(SILType resultType);
+    llvm::Type *addIndirectResult(SILType resultType, bool useInReg = false);
 
     SILFunctionConventions getSILFuncConventions() const {
       return SILFunctionConventions(FnType, IGM.getSILModule());
@@ -533,11 +536,12 @@ namespace {
 } // end namespace irgen
 } // end namespace swift
 
-llvm::Type *SignatureExpansion::addIndirectResult(SILType resultType) {
+llvm::Type *SignatureExpansion::addIndirectResult(SILType resultType,
+                                                  bool useInReg) {
   const TypeInfo &resultTI = IGM.getTypeInfo(resultType);
   auto storageTy = resultTI.getStorageType();
   addIndirectResultAttributes(IGM, Attrs, ParamIRTypes.size(), claimSRet(),
-                              storageTy, resultTI);
+                              storageTy, resultTI, useInReg);
   addPointerParameter(storageTy);
   return IGM.VoidTy;
 }
@@ -1449,9 +1453,15 @@ void SignatureExpansion::expandExternalSignatureTypes() {
   // Generate function info for this signature.
   auto extInfo = clang::FunctionType::ExtInfo();
 
-  auto &FI = clang::CodeGen::arrangeFreeFunctionCall(IGM.ClangCodeGen->CGM(),
-                                             clangResultTy, paramTys, extInfo,
-                                             clang::CodeGen::RequiredArgs::All);
+  bool isCXXMethod =
+      FnType->getRepresentation() == SILFunctionTypeRepresentation::CXXMethod;
+  auto &FI = isCXXMethod ?
+      clang::CodeGen::arrangeCXXMethodCall(IGM.ClangCodeGen->CGM(),
+          clangResultTy, paramTys, extInfo, {},
+          clang::CodeGen::RequiredArgs::All) :
+      clang::CodeGen::arrangeFreeFunctionCall(IGM.ClangCodeGen->CGM(),
+          clangResultTy, paramTys, extInfo, {},
+          clang::CodeGen::RequiredArgs::All);
   ForeignInfo.ClangInfo = &FI;
 
   assert(FI.arg_size() == paramTys.size() &&
@@ -1573,16 +1583,14 @@ void SignatureExpansion::expandExternalSignatureTypes() {
   if (returnInfo.isIndirect()) {
     auto resultType = getSILFuncConventions().getSingleSILResultType(
         IGM.getMaximalTypeExpansionContext());
-    if (IGM.Triple.isWindowsMSVCEnvironment() &&
-        FnType->getRepresentation() ==
-            SILFunctionTypeRepresentation::CXXMethod) {
+    if (returnInfo.isSRetAfterThis()) {
       // Windows ABI places `this` before the
       // returned indirect values.
       emitArg(0);
       firstParamToLowerNormally = 1;
-      addIndirectResult(resultType);
+      addIndirectResult(resultType, returnInfo.getInReg());
     } else
-      addIndirectResult(resultType);
+      addIndirectResult(resultType, returnInfo.getInReg());
   }
 
   // Use a special IR type for passing block pointers.
@@ -2534,11 +2542,12 @@ class SyncCallEmission final : public CallEmission {
 
         // Windows ABI places `this` before the
         // returned indirect values.
-        bool isThisFirst = IGF.IGM.Triple.isWindowsMSVCEnvironment();
-        if (!isThisFirst)
+        auto &returnInfo =
+            getCallee().getForeignInfo().ClangInfo->getReturnInfo();
+        if (returnInfo.isIndirect() && !returnInfo.isSRetAfterThis())
           passIndirectResults();
         adjusted.add(arg);
-        if (isThisFirst)
+        if (returnInfo.isIndirect() && returnInfo.isSRetAfterThis())
           passIndirectResults();
       }
 
@@ -3115,9 +3124,10 @@ void CallEmission::emitToUnmappedMemory(Address result) {
   assert(LastArgWritten == 1 && "emitting unnaturally to indirect result");
 
   Args[0] = result.getAddress();
-  if (IGF.IGM.Triple.isWindowsMSVCEnvironment() &&
-      getCallee().getRepresentation() ==
-          SILFunctionTypeRepresentation::CXXMethod &&
+
+  auto *FI = getCallee().getForeignInfo().ClangInfo;
+  if (FI && FI->getReturnInfo().isIndirect() &&
+      FI->getReturnInfo().isSRetAfterThis() &&
       Args[1] == getCallee().getCXXMethodSelf()) {
     // C++ methods in MSVC ABI pass `this` before the
     // indirectly returned value.
@@ -3482,10 +3492,10 @@ void CallEmission::emitToExplosion(Explosion &out, bool isOutlined) {
       emitToMemory(temp, substResultTI, isOutlined);
       return;
     }
-    if (IGF.IGM.Triple.isWindowsMSVCEnvironment() &&
-        getCallee().getRepresentation() ==
-            SILFunctionTypeRepresentation::CXXMethod &&
-        substResultType.isVoid()) {
+
+    auto *FI = getCallee().getForeignInfo().ClangInfo;
+    if (FI && FI->getReturnInfo().isIndirect() &&
+        FI->getReturnInfo().isSRetAfterThis() && substResultType.isVoid()) {
       // Some C++ methods return a value but are imported as
       // returning `Void` (e.g. `operator +=`). In this case
       // we should allocate the correct temp indirect return

test/Interop/Cxx/class/method/Inputs/inreg-sret.h

@@ -0,0 +1,11 @@
+#ifndef TEST_INTEROP_CXX_CLASS_METHOD_INREG_SRET_H
+#define TEST_INTEROP_CXX_CLASS_METHOD_INREG_SRET_H
+
+struct OptionalBridgedBasicBlock {
+};
+
+struct BridgedFunction {
+  OptionalBridgedBasicBlock getFirstBlock() const { return {}; }
+};
+
+#endif // TEST_INTEROP_CXX_CLASS_METHOD_INREG_SRET_H