[IRGen] Implement support for multi payload enums in layout strings (#…

…66354)

* [IRGen] Implement support for multi payload enums in layout strings

rdar://105837114

* Implement multi payload enum cases in swift_resolve_resilientAccessors

* Add missing const

lib/IRGen/TypeLayout.cpp

@@ -77,7 +77,12 @@ class LayoutStringBuilder {
  Resilient = 0x0f,
  SinglePayloadEnumSimple = 0x10,
  SinglePayloadEnumFN = 0x11,
- SinglePayloadEnumFNResolved = 0x12,
+ // reserved
+ // SinglePayloadEnumFNResolved = 0x12,
+
+ MultiPayloadEnumFN = 0x13,
+ // reserved
+ // MultiPayloadEnumFNResolved = 0x14,
 
  Skip = 0x80,
  // We may use the MSB as flag that a count follows,
@@ -101,13 +106,19 @@ class LayoutStringBuilder {
  const TypeLayoutEntry *payload;
  };
 
+ struct MultiPayloadEnumFN {
+ llvm::Function *tagFn;
+ const EnumTypeLayoutEntry *entry;
+ };
+
  struct RefCounting {
  RefCountingKind kind;
  union {
  size_t size;
- llvm::Function* metaTypeRef;
+ llvm::Function *metaTypeRef;
  SinglePayloadEnumSimple singlePayloadEnumSimple;
  SinglePayloadEnumFN singlePayloadEnumFN;
+ MultiPayloadEnumFN multiPayloadEnumFN;
  };
 
  RefCounting() = default;
@@ -151,6 +162,15 @@ class LayoutStringBuilder {
  refCountings.push_back(op);
  }
 
+ void addMultiPayloadEnumFN(llvm::Function *tagFn,
+ const EnumTypeLayoutEntry *entry) {
+ RefCounting op;
+ op.kind = RefCountingKind::MultiPayloadEnumFN;
+ op.multiPayloadEnumFN.tagFn = tagFn;
+ op.multiPayloadEnumFN.entry = entry;
+ refCountings.push_back(op);
+ }
+
  void addSkip(size_t size) {
  if (refCountings.empty() ||
  refCountings.back().kind != RefCountingKind::Skip) {
@@ -280,6 +300,63 @@ class LayoutStringBuilder {
  break;
  }
 
+ case RefCountingKind::MultiPayloadEnumFN: {
+ uint64_t op = (static_cast<uint64_t>(refCounting.kind) << 56) | skip;
+ B.addInt64(op);
+
+ skip = 0;
+
+ auto enumData = refCounting.multiPayloadEnumFN;
+ auto payloads = enumData.entry->cases;
+
+ B.addRelativeOffset(IGM.IntPtrTy, enumData.tagFn);
+
+ B.addSize(Size(payloads.size()));
+
+ auto nestedRefCountBytesPlaceholder =
+ B.addPlaceholderWithSize(IGM.SizeTy);
+ B.addSize(*enumData.entry->fixedSize(IGM));
+
+ SmallVector<
+ clang::CodeGen::ConstantAggregateBuilderBase::PlaceholderPosition,
+ 4>
+ offsetPlaceholders;
+ for (auto *p : payloads) {
+ (void)p;
+ auto placeholder = B.addPlaceholderWithSize(IGM.SizeTy);
+ offsetPlaceholders.push_back(placeholder);
+ refCountBytes += IGM.getPointerSize().getValue();
+ }
+
+ size_t nestedRefCountBytes = 0;
+ for (auto p : llvm::zip(payloads, offsetPlaceholders)) {
+ auto *payload = std::get<0>(p);
+
+ B.fillPlaceholderWithInt(std::get<1>(p), IGM.SizeTy,
+ nestedRefCountBytes);
+
+ size_t nestedSkip = 0;
+ LayoutStringBuilder nestedBuilder{};
+ payload->refCountString(IGM, nestedBuilder, genericSig);
+ addRefCountings(IGM, B, genericSig, nestedBuilder.refCountings,
+ nestedSkip, nestedRefCountBytes, flags);
+
+ // NUL terminator
+ B.addInt64(0);
+ nestedRefCountBytes += sizeof(uint64_t);
+ }
+
+ B.fillPlaceholderWithInt(nestedRefCountBytesPlaceholder, IGM.SizeTy,
+ nestedRefCountBytes);
+
+ refCountBytes += sizeof(uint64_t) +
+ (4 * IGM.getPointerSize().getValue()) +
+ nestedRefCountBytes;
+
+ flags |= LayoutStringFlags::HasRelativePointers;
+ break;
+ }
+
  default: {
  uint64_t op = (static_cast<uint64_t>(refCounting.kind) << 56) | skip;
  B.addInt64(op);
@@ -2208,6 +2285,22 @@ bool EnumTypeLayoutEntry::buildSinglePayloadRefCountString(
  return true;
 }
 
+bool EnumTypeLayoutEntry::buildMultiPayloadRefCountString(
+ IRGenModule &IGM, LayoutStringBuilder &B,
+ GenericSignature genericSig) const {
+ auto valid = std::all_of(cases.begin(), cases.end(), [&](auto *c) {
+ LayoutStringBuilder nestedBuilder{};
+ return c->refCountString(IGM, nestedBuilder, genericSig);
+ });
+
+ if (valid) {
+ auto *tagFn = createFixedEnumLoadTag(IGM, *this);
+ B.addMultiPayloadEnumFN(tagFn, this);
+ }
+
+ return valid;
+}
+
 llvm::Constant *
 EnumTypeLayoutEntry::layoutString(IRGenModule &IGM,
  GenericSignature genericSig) const {
@@ -2245,12 +2338,20 @@ EnumTypeLayoutEntry::layoutString(IRGenModule &IGM,
  return nullptr;
 
  case CopyDestroyStrategy::Normal: {
- if (!isFixedSize(IGM) || isMultiPayloadEnum() ||
- !buildSinglePayloadRefCountString(IGM, B, genericSig)) {
- return *(_layoutString = llvm::Optional<llvm::Constant *>(nullptr));
+ bool valid = false;
+ if (isFixedSize(IGM)) {
+ if (isMultiPayloadEnum()) {
+ valid = buildMultiPayloadRefCountString(IGM, B, genericSig);
+ } else {
+ valid = buildSinglePayloadRefCountString(IGM, B, genericSig);
+ }
  }
 
- return createConstant(B);
+ if (valid) {
+ return createConstant(B);
+ } else {
+ return *(_layoutString = llvm::Optional<llvm::Constant *>(nullptr));
+ }
  }
 
  case CopyDestroyStrategy::ForwardToPayload:
@@ -2281,8 +2382,11 @@ bool EnumTypeLayoutEntry::refCountString(IRGenModule &IGM,
  case CopyDestroyStrategy::ForwardToPayload:
  return cases[0]->refCountString(IGM, B, genericSig);
  case CopyDestroyStrategy::Normal: {
- if (!isMultiPayloadEnum() &&
- buildSinglePayloadRefCountString(IGM, B, genericSig)) {
+
+ if (isMultiPayloadEnum() &&
+ buildMultiPayloadRefCountString(IGM, B, genericSig)) {
+ return true;
+ } else if (buildSinglePayloadRefCountString(IGM, B, genericSig)) {
  return true;
  }
 

lib/IRGen/TypeLayout.h

@@ -651,6 +651,9 @@ class EnumTypeLayoutEntry : public TypeLayoutEntry,
  LayoutStringBuilder &B,
  GenericSignature genericSig) const;
 
+ bool buildMultiPayloadRefCountString(IRGenModule &IGM, LayoutStringBuilder &B,
+ GenericSignature genericSig) const;
+
  static bool classof(const TypeLayoutEntry *entry);
 };