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GenReflection.cpp
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//===--- GenReflection.cpp - IR generation for nominal type reflection ----===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file implements IR generation of type metadata for struct/class
// stored properties and enum cases for use with reflection.
//===----------------------------------------------------------------------===//
#include "swift/AST/Decl.h"
#include "swift/AST/DiagnosticsIRGen.h"
#include "swift/AST/GenericEnvironment.h"
#include "swift/AST/IRGenOptions.h"
#include "swift/AST/PrettyStackTrace.h"
#include "swift/AST/ProtocolConformance.h"
#include "swift/AST/SubstitutionMap.h"
#include "swift/Basic/Assertions.h"
#include "swift/Basic/Platform.h"
#include "swift/IRGen/Linking.h"
#include "swift/RemoteInspection/MetadataSourceBuilder.h"
#include "swift/RemoteInspection/Records.h"
#include "swift/SIL/SILModule.h"
#include "ConstantBuilder.h"
#include "Explosion.h"
#include "Field.h"
#include "GenClass.h"
#include "GenDecl.h"
#include "GenEnum.h"
#include "GenHeap.h"
#include "GenMeta.h"
#include "GenProto.h"
#include "GenType.h"
#include "GenValueWitness.h"
#include "IRGenDebugInfo.h"
#include "IRGenFunction.h"
#include "IRGenMangler.h"
#include "IRGenModule.h"
#include "LoadableTypeInfo.h"
#include "MetadataRequest.h"
using namespace swift;
using namespace irgen;
using namespace reflection;
class MetadataSourceEncoder
: public MetadataSourceVisitor<MetadataSourceEncoder> {
llvm::raw_ostream &OS;
public:
MetadataSourceEncoder(llvm::raw_ostream &OS) : OS(OS) {}
void
visitClosureBindingMetadataSource(const ClosureBindingMetadataSource *CB) {
OS << 'B';
OS << CB->getIndex();
}
void
visitReferenceCaptureMetadataSource(const ReferenceCaptureMetadataSource *RC){
OS << 'R';
OS << RC->getIndex();
}
void
visitMetadataCaptureMetadataSource(const MetadataCaptureMetadataSource *MC) {
OS << 'M';
OS << MC->getIndex();
}
void
visitGenericArgumentMetadataSource(const GenericArgumentMetadataSource *GA) {
OS << 'G';
OS << GA->getIndex();
visit(GA->getSource());
OS << '_';
}
void visitSelfMetadataSource(const SelfMetadataSource *S) {
OS << 'S';
}
void
visitSelfWitnessTableMetadataSource(const SelfWitnessTableMetadataSource *S) {
OS << 'W';
}
};
class PrintMetadataSource
: public MetadataSourceVisitor<PrintMetadataSource, void> {
llvm::raw_ostream &OS;
unsigned Indent;
llvm::raw_ostream &indent(unsigned Amount) {
for (unsigned i = 0; i < Amount; ++i)
OS << ' ';
return OS;
}
llvm::raw_ostream &printHeader(std::string Name) {
indent(Indent) << '(' << Name;
return OS;
}
template<typename T>
llvm::raw_ostream &printField(std::string name, const T &value) {
if (!name.empty())
OS << " " << name << "=" << value;
else
OS << " " << value;
return OS;
}
void printRec(const reflection::MetadataSource *MS) {
OS << "\n";
Indent += 2;
visit(MS);
Indent -= 2;
}
void closeForm() {
OS << ')';
}
public:
PrintMetadataSource(llvm::raw_ostream &OS, unsigned Indent)
: OS(OS), Indent(Indent) {}
void
visitClosureBindingMetadataSource(const ClosureBindingMetadataSource *CB) {
printHeader("closure-binding");
printField("index", CB->getIndex());
closeForm();
}
void
visitReferenceCaptureMetadataSource(const ReferenceCaptureMetadataSource *RC){
printHeader("reference-capture");
printField("index", RC->getIndex());
closeForm();
}
void
visitMetadataCaptureMetadataSource(const MetadataCaptureMetadataSource *MC){
printHeader("metadata-capture");
printField("index", MC->getIndex());
closeForm();
}
void
visitGenericArgumentMetadataSource(const GenericArgumentMetadataSource *GA) {
printHeader("generic-argument");
printField("index", GA->getIndex());
printRec(GA->getSource());
closeForm();
}
void
visitSelfMetadataSource(const SelfMetadataSource *S) {
printHeader("self");
closeForm();
}
void
visitSelfWitnessTableMetadataSource(const SelfWitnessTableMetadataSource *S) {
printHeader("self-witness-table");
closeForm();
}
};
std::optional<llvm::VersionTuple>
getRuntimeVersionThatSupportsDemanglingType(CanType type) {
enum VersionRequirement {
None,
Swift_5_2,
Swift_5_5,
Swift_6_0,
// Short-circuit if we find this requirement.
Latest = Swift_6_0
};
VersionRequirement latestRequirement = None;
auto addRequirement = [&](VersionRequirement req) -> bool {
if (req > latestRequirement) {
latestRequirement = req;
return req == Latest;
}
return false;
};
(void) type.findIf([&](CanType t) -> bool {
if (auto fn = dyn_cast<AnyFunctionType>(t)) {
// The Swift 6.0 runtime is the first version able to demangle types
// that involve typed throws or @isolated(any), or for that matter
// represent them at all at runtime.
if (!fn.getThrownError().isNull() || fn->getIsolation().isErased())
return addRequirement(Swift_6_0);
// The Swift 5.5 runtime is the first version able to demangle types
// related to concurrency.
if (fn->isAsync() || fn->isSendable() ||
!fn->getIsolation().isNonIsolated())
return addRequirement(Swift_5_5);
return false;
}
if (auto opaqueArchetype = dyn_cast<OpaqueTypeArchetypeType>(t)) {
// Associated types of opaque types weren't mangled in a usable
// form by the Swift 5.1 runtime, so we needed to add a new
// mangling in 5.2.
if (opaqueArchetype->getInterfaceType()->is<DependentMemberType>())
return addRequirement(Swift_5_2);
// Although opaque types in general were only added in Swift 5.1,
// declarations that use them are already covered by availability
// guards, so we don't need to limit availability of mangled names
// involving them.
}
/// Any nominal type that has an inverse requirement in its generic
/// signature uses NoncopyableGenerics. Since inverses are mangled into
/// symbols, a Swift 6.0+ runtime is generally needed to demangle them.
///
/// We make an exception for types in the stdlib, like Optional, since the
/// runtime should still be able to demangle them, based on the availability
/// of the type.
if (auto nominalTy = dyn_cast<NominalOrBoundGenericNominalType>(t)) {
auto *nom = nominalTy->getDecl();
if (auto sig = nom->getGenericSignature()) {
SmallVector<InverseRequirement, 2> inverses;
SmallVector<Requirement, 2> reqs;
sig->getRequirementsWithInverses(reqs, inverses);
if (!inverses.empty() && !nom->getModuleContext()->isStdlibModule()) {
return addRequirement(Swift_6_0);
}
}
}
// Any composition with an inverse will need the 6.0 runtime to demangle.
if (auto pct = dyn_cast<ProtocolCompositionType>(t)) {
if (pct->hasInverse())
return addRequirement(Swift_6_0);
}
return false;
});
switch (latestRequirement) {
case Swift_6_0: return llvm::VersionTuple(6, 0);
case Swift_5_5: return llvm::VersionTuple(5, 5);
case Swift_5_2: return llvm::VersionTuple(5, 2);
case None: return std::nullopt;
}
llvm_unreachable("bad kind");
}
// Produce a fallback mangled type name that uses an open-coded callback
// to form the metadata. This is useful for working around bugs in older
// runtimes, or supporting new type system features when deploying back.
//
// Note that this functionality is limited, because the demangler callback
// mechanism can only produce complete metadata. It can't be used in situations
// where completing the metadata during demangling might cause cyclic
// dependencies.
static std::pair<llvm::Constant *, unsigned>
getTypeRefByFunction(IRGenModule &IGM,
CanGenericSignature sig,
CanType t) {
IRGenMangler mangler;
std::string symbolName =
mangler.mangleSymbolNameForMangledMetadataAccessorString(
"get_type_metadata", sig, t);
auto constant = IGM.getAddrOfStringForMetadataRef(symbolName, /*align*/2,
/*low bit*/false,
[&](ConstantInitBuilder &B) {
llvm::Function *accessor;
// Otherwise, we need to emit a helper function to bind the arguments
// out of the demangler's argument buffer.
auto fnTy = llvm::FunctionType::get(IGM.TypeMetadataPtrTy,
{IGM.Int8PtrTy}, /*vararg*/ false);
accessor =
llvm::Function::Create(fnTy, llvm::GlobalValue::PrivateLinkage,
symbolName, IGM.getModule());
accessor->setAttributes(IGM.constructInitialAttributes());
SmallVector<GenericRequirement, 4> requirements;
auto *genericEnv = sig.getGenericEnvironment();
enumerateGenericSignatureRequirements(sig,
[&](GenericRequirement reqt) { requirements.push_back(reqt); });
{
IRGenFunction IGF(IGM, accessor);
if (IGM.DebugInfo)
IGM.DebugInfo->emitArtificialFunction(IGF, accessor);
auto bindingsBufPtr = IGF.collectParameters().claimNext();
auto substT = genericEnv
? genericEnv->mapTypeIntoContext(t)->getCanonicalType()
: t;
// If a type is noncopyable, lie about the resolved type unless the
// runtime is sufficiently aware of noncopyable types.
if (substT->isNoncopyable()) {
// Darwin-based platforms have ABI stability, and we want binaries
// that use noncopyable types nongenerically today to be forward
// compatible with a future OS runtime that supports noncopyable
// generics. On other platforms, a new Swift compiler and runtime
// require recompilation anyway, so this dance is unnecessary, and
// for now, we can unconditionally lie.
bool useForwardCompatibility =
IGM.Context.LangOpts.Target.isOSDarwin();
llvm::Instruction *br = nullptr;
llvm::BasicBlock *supportedBB = nullptr;
if (useForwardCompatibility) {
llvm::Value *runtimeSupportsNoncopyableTypesSymbol = nullptr;
// This is weird. When building the stdlib, we don't have access to
// the swift_runtimeSupportsNoncopyableTypes symbol in the Swift.o,
// so we'll emit an adrp + ldr to resolve the GOT address. However,
// this symbol is defined as an abolsute in the runtime object files
// to address 0x0 right now and ld doesn't quite understand how to
// fixup this GOT address when merging the runtime and stdlib. Just
// unconditionally fail the branch.
//
// Note: When the value of this symbol changes, this MUST be
// updated.
if (IGM.getSwiftModule()->isStdlibModule()) {
runtimeSupportsNoncopyableTypesSymbol
= llvm::ConstantInt::get(IGM.Int8Ty, 0);
} else {
runtimeSupportsNoncopyableTypesSymbol
= IGM.Module.getOrInsertGlobal(
"swift_runtimeSupportsNoncopyableTypes", IGM.Int8Ty);
cast<llvm::GlobalVariable>(runtimeSupportsNoncopyableTypesSymbol)
->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
}
auto runtimeSupportsNoncopyableTypes
= IGF.Builder.CreateIsNotNull(runtimeSupportsNoncopyableTypesSymbol,
"supports.noncopyable");
supportedBB = IGF.createBasicBlock("does.support.noncopyable");
auto unsupportedBB = IGF.createBasicBlock("does.not.support.noncopyable");
br = IGF.Builder.CreateCondBr(runtimeSupportsNoncopyableTypes,
supportedBB,
unsupportedBB);
IGF.Builder.emitBlock(unsupportedBB);
}
// If the runtime does not yet support noncopyable types, lie that the
// field is an empty tuple, so the runtime doesn't try to do anything
// with the actual value.
auto phonyRet = IGF.emitTypeMetadataRef(IGM.Context.TheEmptyTupleType);
IGF.Builder.CreateRet(phonyRet);
if (!useForwardCompatibility) {
goto done_building_function;
}
// Emit the type metadata normally otherwise.
IGF.Builder.SetInsertPoint(br);
IGF.Builder.emitBlock(supportedBB);
}
SubstitutionMap subs;
if (genericEnv)
subs = genericEnv->getForwardingSubstitutionMap();
bindFromGenericRequirementsBuffer(
IGF, requirements,
Address(bindingsBufPtr, IGM.Int8Ty, IGM.getPointerAlignment()),
MetadataState::Complete, subs);
auto ret = IGF.emitTypeMetadataRef(substT);
IGF.Builder.CreateRet(ret);
}
done_building_function:
// Form the mangled name with its relative reference.
auto S = B.beginStruct();
S.setPacked(true);
S.add(llvm::ConstantInt::get(IGM.Int8Ty, 255));
S.add(llvm::ConstantInt::get(IGM.Int8Ty, 9));
S.addCompactFunctionReference(accessor);
// And a null terminator!
S.addInt(IGM.Int8Ty, 0);
return S.finishAndCreateFuture();
});
return {constant, 6};
}
bool swift::irgen::mangledNameIsUnknownToDeployTarget(IRGenModule &IGM,
CanType type) {
if (auto runtimeCompatVersion = getSwiftRuntimeCompatibilityVersionForTarget(
IGM.Context.LangOpts.Target)) {
if (auto minimumSupportedRuntimeVersion =
getRuntimeVersionThatSupportsDemanglingType(type)) {
if (*runtimeCompatVersion < *minimumSupportedRuntimeVersion) {
return true;
}
}
}
return false;
}
static std::pair<llvm::Constant *, unsigned>
getTypeRefImpl(IRGenModule &IGM,
CanType type,
CanGenericSignature sig,
MangledTypeRefRole role) {
bool useFlatUnique = false;
switch (role) {
case MangledTypeRefRole::FlatUnique:
useFlatUnique = true;
break;
case MangledTypeRefRole::FieldMetadata: {
// We want to keep fields of noncopyable type from being exposed to
// in-process runtime reflection libraries in older Swift runtimes, since
// they more than likely assume they can copy field values, and the language
// support for noncopyable types as dynamic or generic types isn't yet
// implemented as of the writing of this comment. If the type is
// noncopyable, use a function to emit the type ref which will look for a
// signal from future runtimes whether they support noncopyable types before
// exposing their metadata to them.
Type contextualTy = type;
if (sig) {
contextualTy = sig.getGenericEnvironment()->mapTypeIntoContext(type);
}
bool isAlwaysNoncopyable = false;
if (contextualTy->isNoncopyable()) {
isAlwaysNoncopyable = true;
// If the contextual type has any archetypes in it, it's plausible that
// we could end up with a copyable type in some instances. Look for those
// so we can permit unsafe reflection of the field, by assuming it could
// be Copyable.
if (contextualTy->hasArchetype()) {
// If this is a nominal type, check whether it can ever be copyable.
if (auto nominal = contextualTy->getAnyNominal()) {
// If it's a nominal that can ever be Copyable _and_ it's defined in
// the stdlib, assume that we could end up with a Copyable type.
if (nominal->canBeCopyable()
&& nominal->getModuleContext()->isStdlibModule())
isAlwaysNoncopyable = false;
} else {
// Assume that we could end up with a Copyable type somehow.
// This allows you to reflect a 'T: ~Copyable' stored in a type.
isAlwaysNoncopyable = false;
}
}
}
// The getTypeRefByFunction strategy will emit a forward-compatible runtime
// check to see if the runtime can safely reflect such fields. Otherwise,
// the field will be artificially hidden to reflectors.
if (isAlwaysNoncopyable) {
IGM.IRGen.noteUseOfTypeMetadata(type);
return getTypeRefByFunction(IGM, sig, type);
}
}
LLVM_FALLTHROUGH;
case MangledTypeRefRole::DefaultAssociatedTypeWitness:
case MangledTypeRefRole::Metadata:
// Note that we're using all of the nominal types referenced by this type,
// ensuring that we can always reconstruct type metadata from a mangled name
// in-process.
IGM.IRGen.noteUseOfTypeMetadata(type);
// If the minimum deployment target's runtime demangler wouldn't understand
// this mangled name, then fall back to generating a "mangled name" with a
// symbolic reference with a callback function.
if (mangledNameIsUnknownToDeployTarget(IGM, type)) {
return getTypeRefByFunction(IGM, sig, type);
}
break;
case MangledTypeRefRole::Reflection:
// For reflection records only used for out-of-process reflection, we do not
// need to force emission of runtime type metadata.
IGM.IRGen.noteUseOfFieldDescriptors(type);
break;
}
IRGenMangler Mangler;
auto SymbolicName =
useFlatUnique ? Mangler.mangleTypeForFlatUniqueTypeRef(sig, type)
: Mangler.mangleTypeForReflection(IGM, sig, type);
return {IGM.getAddrOfStringForTypeRef(SymbolicName, role),
SymbolicName.runtimeSizeInBytes()};
}
std::pair<llvm::Constant *, unsigned>
IRGenModule::getTypeRef(CanType type, CanGenericSignature sig,
MangledTypeRefRole role) {
type = substOpaqueTypesWithUnderlyingTypes(type);
return getTypeRefImpl(*this, type, sig, role);
}
std::pair<llvm::Constant *, unsigned>
IRGenModule::getTypeRef(Type type, GenericSignature genericSig,
MangledTypeRefRole role) {
return getTypeRef(type->getReducedType(genericSig),
genericSig.getCanonicalSignature(), role);
}
std::pair<llvm::Constant *, unsigned>
IRGenModule::getLoweredTypeRef(SILType loweredType,
CanGenericSignature genericSig,
MangledTypeRefRole role) {
auto substTy =
substOpaqueTypesWithUnderlyingTypes(loweredType, genericSig);
auto type = substTy.getASTType();
return getTypeRefImpl(*this, type, genericSig, role);
}
/// Emit a mangled string referencing a specific protocol conformance, so that
/// the runtime can fetch its witness table.
///
/// TODO: Currently this uses a stub mangling that just refers to an accessor
/// function. We need to fully develop the mangling with the ability to refer
/// to dependent conformances to be able to use mangled strings.
llvm::Constant *
IRGenModule::emitWitnessTableRefString(CanType type,
ProtocolConformanceRef conformance,
GenericSignature origGenericSig,
bool shouldSetLowBit) {
std::tie(type, conformance)
= substOpaqueTypesWithUnderlyingTypes(type, conformance);
auto origType = type;
auto genericSig = origGenericSig.getCanonicalSignature();
SmallVector<GenericRequirement, 4> requirements;
enumerateGenericSignatureRequirements(genericSig,
[&](GenericRequirement reqt) { requirements.push_back(reqt); });
auto *genericEnv = genericSig.getGenericEnvironment();
IRGenMangler mangler;
std::string symbolName =
mangler.mangleSymbolNameForMangledConformanceAccessorString(
"get_witness_table", genericSig, type, conformance);
return getAddrOfStringForMetadataRef(symbolName, /*alignment=*/2,
shouldSetLowBit,
[&](ConstantInitBuilder &B) {
// Build a stub that loads the necessary bindings from the key path's
// argument buffer then fetches the metadata.
auto fnTy = llvm::FunctionType::get(WitnessTablePtrTy,
{Int8PtrTy}, /*vararg*/ false);
auto accessorThunk =
llvm::Function::Create(fnTy, llvm::GlobalValue::PrivateLinkage,
symbolName, getModule());
accessorThunk->setAttributes(constructInitialAttributes());
{
IRGenFunction IGF(*this, accessorThunk);
if (DebugInfo)
DebugInfo->emitArtificialFunction(IGF, accessorThunk);
if (type->hasTypeParameter()) {
auto bindingsBufPtr = IGF.collectParameters().claimNext();
bindFromGenericRequirementsBuffer(
IGF, requirements,
Address(bindingsBufPtr, Int8Ty, getPointerAlignment()),
MetadataState::Complete, genericEnv->getForwardingSubstitutionMap());
type = genericEnv->mapTypeIntoContext(type)->getCanonicalType();
}
if (origType->hasTypeParameter()) {
conformance = conformance.subst(origType,
genericEnv->getForwardingSubstitutionMap());
}
auto ret = emitWitnessTableRef(IGF, type, conformance);
IGF.Builder.CreateRet(ret);
}
// Form the mangled name with its relative reference.
auto S = B.beginStruct();
S.setPacked(true);
S.add(llvm::ConstantInt::get(Int8Ty, 255));
S.add(llvm::ConstantInt::get(Int8Ty, 9));
S.addCompactFunctionReference(accessorThunk);
// And a null terminator!
S.addInt(Int8Ty, 0);
return S.finishAndCreateFuture();
});
}
llvm::Constant *IRGenModule::getMangledAssociatedConformance(
const NormalProtocolConformance *conformance,
const AssociatedConformance &requirement) {
// Figure out the name of the symbol to be used for the conformance.
IRGenMangler mangler;
auto symbolName =
mangler.mangleSymbolNameForAssociatedConformanceWitness(
conformance, requirement.getAssociation(),
requirement.getAssociatedRequirement());
// See if we emitted the constant already.
auto &entry = StringsForTypeRef[symbolName];
if (entry.second) {
return entry.second;
}
// Get the accessor for this associated conformance.
llvm::Function *accessor;
unsigned char kind;
if (conformance) {
kind = 7;
accessor = getAddrOfAssociatedTypeWitnessTableAccessFunction(conformance,
requirement);
} else {
kind = 8;
accessor = getAddrOfDefaultAssociatedConformanceAccessor(requirement);
}
// Form the mangled name with its relative reference.
ConstantInitBuilder B(*this);
auto S = B.beginStruct();
S.setPacked(true);
S.add(llvm::ConstantInt::get(Int8Ty, 255));
S.add(llvm::ConstantInt::get(Int8Ty, kind));
S.addCompactFunctionReference(accessor);
// And a null terminator!
S.addInt(Int8Ty, 0);
auto finished = S.finishAndCreateFuture();
auto var = new llvm::GlobalVariable(Module, finished.getType(),
/*constant*/ true,
llvm::GlobalValue::LinkOnceODRLinkage,
nullptr,
symbolName);
ApplyIRLinkage(IRLinkage::InternalLinkOnceODR).to(var);
var->setAlignment(llvm::MaybeAlign(2));
setTrueConstGlobal(var);
var->setSection(getReflectionTypeRefSectionName());
finished.installInGlobal(var);
// Drill down to the i8* at the beginning of the constant.
auto addr = llvm::ConstantExpr::getBitCast(var, Int8PtrTy);
// Set the low bit.
unsigned bit = ProtocolRequirementFlags::AssociatedTypeMangledNameBit;
auto bitConstant = llvm::ConstantInt::get(IntPtrTy, bit);
addr = llvm::ConstantExpr::getGetElementPtr(Int8Ty, addr, bitConstant);
// Update the entry.
entry = {var, addr};
return addr;
}
class ReflectionMetadataBuilder {
protected:
IRGenModule &IGM;
ConstantInitBuilder InitBuilder;
ConstantStructBuilder B;
ReflectionMetadataBuilder(IRGenModule &IGM)
: IGM(IGM), InitBuilder(IGM), B(InitBuilder.beginStruct()) {}
virtual ~ReflectionMetadataBuilder() {}
// Collect any builtin types referenced from this type.
void addBuiltinTypeRefs(CanType type) {
if (IGM.getSwiftModule()->isStdlibModule()) {
type.visit([&](CanType t) {
if (isa<BuiltinType>(t))
IGM.BuiltinTypes.insert(t);
});
}
}
/// Add a 32-bit relative offset to a mangled typeref string
/// in the typeref reflection section.
///
/// By default, we use MangledTypeRefRole::Reflection, which does not
/// force emission of any type metadata referenced from the typeref.
///
/// For reflection records which are demangled to produce type metadata
/// in-process, pass MangledTypeRefRole::Metadata instead.
void addTypeRef(Type type, GenericSignature genericSig,
MangledTypeRefRole role =
MangledTypeRefRole::Reflection) {
addTypeRef(type->getReducedType(genericSig),
genericSig.getCanonicalSignature(), role);
}
/// Add a 32-bit relative offset to a mangled typeref string
/// in the typeref reflection section.
///
/// By default, we use MangledTypeRefRole::Reflection, which does not
/// force emission of any type metadata referenced from the typeref.
///
/// For reflection records which are demangled to produce type metadata
/// in-process, pass MangledTypeRefRole::Metadata instead.
void addTypeRef(CanType type,
CanGenericSignature sig,
MangledTypeRefRole role =
MangledTypeRefRole::Reflection) {
B.addRelativeAddress(IGM.getTypeRef(type, sig, role).first);
addBuiltinTypeRefs(type);
}
void
addLoweredTypeRef(SILType loweredType,
CanGenericSignature genericSig,
MangledTypeRefRole role = MangledTypeRefRole::Reflection) {
B.addRelativeAddress(
IGM.getLoweredTypeRef(loweredType, genericSig, role).first);
addBuiltinTypeRefs(loweredType.getASTType());
}
/// Add a 32-bit relative offset to a mangled nominal type string
/// in the typeref reflection section.
///
/// See above comment about 'role'.
void addNominalRef(const NominalTypeDecl *nominal,
MangledTypeRefRole role =
MangledTypeRefRole::Reflection) {
if (auto proto = dyn_cast<ProtocolDecl>(nominal)) {
IRGenMangler mangler;
SymbolicMangling mangledStr;
mangledStr.String = mangler.mangleBareProtocol(proto);
auto mangledName =
IGM.getAddrOfStringForTypeRef(mangledStr, role);
B.addRelativeAddress(mangledName);
} else {
addTypeRef(nominal->getDeclaredType(), GenericSignature(), role);
}
}
// A function signature for a lambda wrapping an IRGenModule::getAddrOf*
// method.
using GetAddrOfEntityFn = llvm::Constant* (IRGenModule &, ConstantInit);
llvm::GlobalVariable *
emit(std::optional<llvm::function_ref<GetAddrOfEntityFn>> getAddr,
const char *section) {
layout();
llvm::GlobalVariable *var;
// Some reflection records have a mangled symbol name, for uniquing
// imported type metadata.
if (getAddr) {
auto init = B.finishAndCreateFuture();
var = cast<llvm::GlobalVariable>((*getAddr)(IGM, init));
var->setConstant(true);
// Others, such as capture descriptors, do not have a name.
} else {
var = B.finishAndCreateGlobal("\x01l__swift5_reflection_descriptor",
Alignment(4), /*isConstant*/ true,
llvm::GlobalValue::PrivateLinkage);
}
var->setSection(section);
// Only mark the reflection record as used when emitting for the runtime.
// In ReflectionMetadataMode::DebuggerOnly mode we want to allow the linker
// to remove/dead-strip these.
if (IGM.IRGen.Opts.ReflectionMetadata == ReflectionMetadataMode::Runtime) {
IGM.addUsedGlobal(var);
}
disableAddressSanitizer(IGM, var);
return var;
}
llvm::GlobalVariable *emit(std::nullopt_t none, const char *section) {
return emit(std::optional<llvm::function_ref<GetAddrOfEntityFn>>(),
section);
}
virtual void layout() = 0;
};
class AssociatedTypeMetadataBuilder : public ReflectionMetadataBuilder {
static const uint32_t AssociatedTypeRecordSize = 8;
const ProtocolConformance *Conformance;
ArrayRef<std::pair<StringRef, CanType>> AssociatedTypes;
void layout() override {
PrettyStackTraceConformance DebugStack("emitting associated type metadata",
Conformance);
auto *DC = Conformance->getDeclContext();
addNominalRef(DC->getSelfNominalTypeDecl());
addNominalRef(Conformance->getProtocol());
B.addInt32(AssociatedTypes.size());
B.addInt32(AssociatedTypeRecordSize);
auto genericSig = DC->getGenericSignatureOfContext().getCanonicalSignature();
for (auto AssocTy : AssociatedTypes) {
auto NameGlobal = IGM.getAddrOfFieldName(AssocTy.first);
B.addRelativeAddress(NameGlobal);
addTypeRef(AssocTy.second, genericSig);
}
}
public:
AssociatedTypeMetadataBuilder(IRGenModule &IGM,
const ProtocolConformance *Conformance,
ArrayRef<std::pair<StringRef, CanType>> AssociatedTypes)
: ReflectionMetadataBuilder(IGM), Conformance(Conformance),
AssociatedTypes(AssociatedTypes) {}
llvm::GlobalVariable *emit() {
auto section = IGM.getAssociatedTypeMetadataSectionName();
llvm::GlobalVariable *var = ReflectionMetadataBuilder::emit(
[&](IRGenModule &IGM, ConstantInit init) -> llvm::Constant * {
return IGM.getAddrOfReflectionAssociatedTypeDescriptor(Conformance,
init);
},
section);
if (IGM.IRGen.Opts.ConditionalRuntimeRecords) {
// Allow dead-stripping `var` (the reflection record) when the protocol
// or type (from the conformance) is not referenced.
IGM.appendLLVMUsedConditionalEntry(var, Conformance);
}
return var;
}
};
class FieldTypeMetadataBuilder : public ReflectionMetadataBuilder {
public:
static const uint32_t FieldRecordSize = 12;
private:
const NominalTypeDecl *NTD;
void addField(reflection::FieldRecordFlags flags,
Type type, StringRef name) {
B.addInt32(flags.getRawValue());
if (!type) {
B.addInt32(0);
} else {
auto genericSig = NTD->getGenericSignature();
// Special case, UFOs are opaque pointers for now.
if (type->isForeignReferenceType()) {
auto opaqueType = type->getASTContext().getOpaquePointerType();
// The standard library's Mirror demangles metadata from field
// descriptors, so use MangledTypeRefRole::FieldMetadata to ensure
// runtime metadata is available.
addTypeRef(opaqueType, genericSig, MangledTypeRefRole::FieldMetadata);
} else {
// The standard library's Mirror demangles metadata from field
// descriptors, so use MangledTypeRefRole::FieldMetadata to ensure
// runtime metadata is available.
addTypeRef(type, genericSig, MangledTypeRefRole::FieldMetadata);
}
}
if (IGM.IRGen.Opts.EnableReflectionNames) {
auto fieldName = IGM.getAddrOfFieldName(name);
B.addRelativeAddress(fieldName);
} else {
B.addInt32(0);
}
}
void addField(Field field) {
reflection::FieldRecordFlags flags;
bool isLet = false;
switch (field.getKind()) {
case Field::Var: {
auto var = field.getVarDecl();
isLet = var->isLet();
break;
}
case Field::MissingMember:
llvm_unreachable("emitting reflection for type with missing member");
case Field::DefaultActorStorage:
flags.setIsArtificial();
break;
case Field::NonDefaultDistributedActorStorage:
flags.setIsArtificial();
break;
}
flags.setIsVar(!isLet);
addField(flags, field.getInterfaceType(IGM), field.getName());
}
void layoutRecord() {
auto kind = FieldDescriptorKind::Struct;
if (auto CD = dyn_cast<ClassDecl>(NTD)) {
auto type = CD->getDeclaredType()->getCanonicalType();
auto RC = type->getReferenceCounting();
if (RC == ReferenceCounting::ObjC)
kind = FieldDescriptorKind::ObjCClass;
else
kind = FieldDescriptorKind::Class;
}
B.addInt16(uint16_t(kind));
B.addInt16(FieldRecordSize);
B.addInt32(getNumFields(NTD));
forEachField(IGM, NTD, [&](Field field) {
addField(field);
});
}
void addField(const EnumDecl *enumDecl, const EnumElementDecl *decl,
bool hasPayload) {
reflection::FieldRecordFlags flags;
if (hasPayload && (decl->isIndirect() || enumDecl->isIndirect()))
flags.setIsIndirectCase();
Type interfaceType = decl->isAvailableDuringLowering()
? decl->getArgumentInterfaceType()
: nullptr;
addField(flags, interfaceType, decl->getBaseIdentifier().str());
}
void layoutEnum() {
auto enumDecl = cast<EnumDecl>(NTD);
auto &strategy = irgen::getEnumImplStrategy(
IGM, enumDecl->getDeclaredTypeInContext()
->getCanonicalType());
auto kind = FieldDescriptorKind::Enum;
if (strategy.getElementsWithPayload().size() > 1 &&
!strategy.needsPayloadSizeInMetadata()) {
kind = FieldDescriptorKind::MultiPayloadEnum;
}
B.addInt16(uint16_t(kind));
B.addInt16(FieldRecordSize);
B.addInt32(strategy.getElementsWithPayload().size()
+ strategy.getElementsWithNoPayload().size());
for (auto enumCase : strategy.getElementsWithPayload()) {
addField(enumDecl, enumCase.decl, /*has payload*/ true);
}
for (auto enumCase : strategy.getElementsWithNoPayload()) {
addField(enumDecl, enumCase.decl, /*has payload*/ false);
}
}
void layoutProtocol() {
auto PD = cast<ProtocolDecl>(NTD);
FieldDescriptorKind Kind;
if (PD->isObjC())
Kind = FieldDescriptorKind::ObjCProtocol;
else if (PD->requiresClass())
Kind = FieldDescriptorKind::ClassProtocol;
else
Kind = FieldDescriptorKind::Protocol;
B.addInt16(uint16_t(Kind));
B.addInt16(FieldRecordSize);
B.addInt32(0);
}
void layout() override {
if (NTD->hasClangNode()) {
auto *enumDecl = dyn_cast<EnumDecl>(NTD);
// Structs and namespace-like enums are ok.
assert(isa<StructDecl>(NTD) || (enumDecl && !enumDecl->hasCases()));
}
PrettyStackTraceDecl DebugStack("emitting field type metadata", NTD);
addNominalRef(NTD);