averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-14 20:36:38 +01:00
Code Issues Packages Projects Releases Wiki Activity
Files
41700b03da4a7e04d8889f17cb159926a53f32ff
swift-mirror/lib/IRGen/GenDecl.cpp
John McCall bafeb84a56 Generate unique type metadata for foreign classes. 
Swift SVN r17430
2014-05-05 06:45:42 +00:00

1736 lines
64 KiB
C++
Raw Blame History

//===--- GenDecl.cpp - IR Generation for Declarations ---------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file implements IR generation for local and global
// declarations in Swift.
//
//===----------------------------------------------------------------------===//
#include "swift/AST/ASTContext.h"
#include "swift/AST/Attr.h"
#include "swift/AST/Decl.h"
#include "swift/AST/IRGenOptions.h"
#include "swift/AST/Module.h"
#include "swift/AST/NameLookup.h"
#include "swift/AST/Pattern.h"
#include "swift/AST/TypeMemberVisitor.h"
#include "swift/AST/Types.h"
#include "swift/Basic/Fallthrough.h"
#include "swift/ClangImporter/ClangModule.h"
#include "swift/SIL/FormalLinkage.h"
#include "swift/SIL/SILDebugScope.h"
#include "swift/SIL/SILModule.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/TypeBuilder.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/ConvertUTF.h"
#include "CallingConvention.h"
#include "Explosion.h"
#include "FormalType.h"
#include "GenClass.h"
#include "GenObjC.h"
#include "GenMeta.h"
#include "IRGenDebugInfo.h"
#include "IRGenFunction.h"
#include "IRGenModule.h"
#include "Linking.h"
#include "TypeInfo.h"
using namespace swift;
using namespace irgen;
static bool isTypeMetadataEmittedLazily(CanType type) {
// All classes have eagerly-emitted metadata (at least for now).
if (type.getClassOrBoundGenericClass()) return false;
switch (getTypeLinkage(type)) {
case FormalLinkage::PublicUnique:
case FormalLinkage::HiddenUnique:
case FormalLinkage::Private:
// Maybe this *should* be lazy for private types?
return false;
case FormalLinkage::PublicNonUnique:
case FormalLinkage::HiddenNonUnique:
return true;
}
llvm_unreachable("bad formal linkage");
}
/// Generates a function to call +load on all the given classes.
static llvm::Function *emitObjCClassInitializer(IRGenModule &IGM,
ArrayRef<llvm::WeakVH> classes){
llvm::FunctionType *fnType =
llvm::FunctionType::get(llvm::Type::getVoidTy(IGM.LLVMContext), false);
llvm::Function *initFn =
llvm::Function::Create(fnType, llvm::GlobalValue::InternalLinkage,
"_swift_initObjCClasses", &IGM.Module);
IRGenFunction initIGF(IGM, initFn);
if (IGM.DebugInfo)
IGM.DebugInfo->emitArtificialFunction(initIGF, initFn);
llvm::Value *loadSel = initIGF.emitObjCSelectorRefLoad("load");
llvm::Type *msgSendParams[] = {
IGM.ObjCPtrTy,
IGM.ObjCSELTy
};
llvm::FunctionType *msgSendType =
llvm::FunctionType::get(llvm::Type::getVoidTy(IGM.LLVMContext),
msgSendParams, false);
llvm::Constant *msgSend =
llvm::ConstantExpr::getBitCast(IGM.getObjCMsgSendFn(),
msgSendType->getPointerTo());
for (auto nextClass : classes) {
llvm::Constant *receiver =
llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(nextClass),
IGM.ObjCPtrTy);
initIGF.Builder.CreateCall2(msgSend, receiver, loadSel);
}
initIGF.Builder.CreateRetVoid();
return initFn;
}
namespace {
class CategoryInitializerVisitor
: public ClassMemberVisitor<CategoryInitializerVisitor>
{
IRGenFunction &IGF;
llvm::Constant *class_replaceMethod;
llvm::Constant *class_addProtocol;
llvm::Constant *classMetadata;
llvm::Constant *metaclassMetadata;
public:
CategoryInitializerVisitor(IRGenFunction &IGF, ExtensionDecl *ext)
: IGF(IGF)
{
class_replaceMethod = IGF.IGM.getClassReplaceMethodFn();
class_addProtocol = IGF.IGM.getClassAddProtocolFn();
CanType origTy = ext->getDeclaredTypeOfContext()->getCanonicalType();
classMetadata = tryEmitConstantHeapMetadataRef(IGF.IGM, origTy);
assert(classMetadata &&
"extended objc class doesn't have constant metadata?!");
classMetadata = llvm::ConstantExpr::getBitCast(classMetadata,
IGF.IGM.ObjCClassPtrTy);
metaclassMetadata = IGF.IGM.getAddrOfMetaclassObject(
origTy.getClassOrBoundGenericClass(),
NotForDefinition);
metaclassMetadata = llvm::ConstantExpr::getBitCast(metaclassMetadata,
IGF.IGM.ObjCClassPtrTy);
// Register ObjC protocol conformances.
for (auto *p : ext->getProtocols()) {
if (!p->isObjC())
continue;
auto proto = IGF.IGM.getAddrOfObjCProtocolRecord(p, NotForDefinition);
IGF.Builder.CreateCall2(class_addProtocol, classMetadata, proto);
}
}
void visitMembers(ExtensionDecl *ext) {
for (Decl *member : ext->getMembers())
visit(member);
}
void visitFuncDecl(FuncDecl *method) {
if (!requiresObjCMethodDescriptor(method)) return;
llvm::Constant *name, *imp, *types;
emitObjCMethodDescriptorParts(IGF.IGM, method, name, types, imp);
// When generating JIT'd code, we need to call sel_registerName() to force
// the runtime to unique the selector.
llvm::Value *sel = IGF.Builder.CreateCall(IGF.IGM.getObjCSelRegisterNameFn(),
name);
llvm::Value *args[] = {
method->isStatic() ? metaclassMetadata : classMetadata,
sel,
imp,
types
};
IGF.Builder.CreateCall(class_replaceMethod, args);
}
void visitConstructorDecl(ConstructorDecl *constructor) {
if (!requiresObjCMethodDescriptor(constructor)) return;
llvm::Constant *name, *imp, *types;
emitObjCMethodDescriptorParts(IGF.IGM, constructor, name, types, imp);
// When generating JIT'd code, we need to call sel_registerName() to force
// the runtime to unique the selector.
llvm::Value *sel = IGF.Builder.CreateCall(IGF.IGM.getObjCSelRegisterNameFn(),
name);
llvm::Value *args[] = {
classMetadata,
sel,
imp,
types
};
IGF.Builder.CreateCall(class_replaceMethod, args);
}
void visitVarDecl(VarDecl *prop) {
if (!requiresObjCPropertyDescriptor(IGF.IGM, prop)) return;
// FIXME: register property metadata in addition to the methods.
// Don't emit getters/setters for @NSManagedAttr properties.
if (prop->getAttrs().hasAttribute<NSManagedAttr>())
return;
llvm::Constant *name, *imp, *types;
emitObjCGetterDescriptorParts(IGF.IGM, prop,
name, types, imp);
// When generating JIT'd code, we need to call sel_registerName() to force
// the runtime to unique the selector.
llvm::Value *sel = IGF.Builder.CreateCall(IGF.IGM.getObjCSelRegisterNameFn(),
name);
llvm::Value *getterArgs[] = {classMetadata, sel, imp, types};
IGF.Builder.CreateCall(class_replaceMethod, getterArgs);
if (prop->isSettable(prop->getDeclContext())) {
emitObjCSetterDescriptorParts(IGF.IGM, prop,
name, types, imp);
sel = IGF.Builder.CreateCall(IGF.IGM.getObjCSelRegisterNameFn(),
name);
llvm::Value *setterArgs[] = {classMetadata, sel, imp, types};
IGF.Builder.CreateCall(class_replaceMethod, setterArgs);
}
}
void visitSubscriptDecl(SubscriptDecl *subscript) {
if (!requiresObjCSubscriptDescriptor(IGF.IGM, subscript)) return;
llvm::Constant *name, *imp, *types;
emitObjCGetterDescriptorParts(IGF.IGM, subscript,
name, types, imp);
// When generating JIT'd code, we need to call sel_registerName() to force
// the runtime to unique the selector.
llvm::Value *sel = IGF.Builder.CreateCall(IGF.IGM.getObjCSelRegisterNameFn(),
name);
llvm::Value *getterArgs[] = {classMetadata, sel, imp, types};
IGF.Builder.CreateCall(class_replaceMethod, getterArgs);
if (subscript->isSettable()) {
emitObjCSetterDescriptorParts(IGF.IGM, subscript,
name, types, imp);
sel = IGF.Builder.CreateCall(IGF.IGM.getObjCSelRegisterNameFn(),
name);
llvm::Value *setterArgs[] = {classMetadata, sel, imp, types};
IGF.Builder.CreateCall(class_replaceMethod, setterArgs);
}
}
};
} // end anonymous namespace
static llvm::Function *emitObjCCategoryInitializer(IRGenModule &IGM,
ArrayRef<ExtensionDecl*> categories) {
llvm::FunctionType *fnType =
llvm::FunctionType::get(llvm::Type::getVoidTy(IGM.LLVMContext), false);
llvm::Function *initFn =
llvm::Function::Create(fnType, llvm::GlobalValue::InternalLinkage,
"_swift_initObjCCategories", &IGM.Module);
IRGenFunction initIGF(IGM, initFn);
if (IGM.DebugInfo)
IGM.DebugInfo->emitArtificialFunction(initIGF, initFn);
for (ExtensionDecl *ext : categories) {
CategoryInitializerVisitor(initIGF, ext).visitMembers(ext);
}
initIGF.Builder.CreateRetVoid();
return initFn;
}
namespace {
class PrettySourceFileEmission : public llvm::PrettyStackTraceEntry {
const SourceFile &SF;
public:
explicit PrettySourceFileEmission(const SourceFile &SF) : SF(SF) {}
virtual void print(raw_ostream &os) const override {
os << "While emitting IR for source file " << SF.getFilename() << '\n';
}
};
} // end anonymous namespace
/// Emit all the top-level code in the source file.
void IRGenModule::emitSourceFile(SourceFile &SF, unsigned StartElem) {
PrettySourceFileEmission StackEntry(SF);
// Emit types and other global decls.
for (unsigned i = StartElem, e = SF.Decls.size(); i != e; ++i)
emitGlobalDecl(SF.Decls[i]);
SF.forAllVisibleModules([&](swift::Module::ImportedModule import) {
import.second->collectLinkLibraries([this](LinkLibrary linkLib) {
this->addLinkLibrary(linkLib);
});
});
// Library files have no entry point.
if (!SF.isScriptMode()) {
return;
}
// Emit main().
// FIXME: We should only emit this in non-JIT modes.
// Look for an entrypoint function in the SIL module.
llvm::Function *topLevelCodeFn = nullptr;
if (auto topLevelCodeSILFn =
SILMod->lookUpFunction(SWIFT_ENTRY_POINT_FUNCTION)) {
topLevelCodeFn = getAddrOfSILFunction(topLevelCodeSILFn, NotForDefinition);
}
llvm::Type* argcArgvTypes[2] = {
llvm::TypeBuilder<llvm::types::i<32>, true>::get(LLVMContext),
llvm::TypeBuilder<llvm::types::i<8>**, true>::get(LLVMContext)
};
llvm::Function *mainFn =
llvm::Function::Create(
llvm::FunctionType::get(Int32Ty, argcArgvTypes, false),
llvm::GlobalValue::ExternalLinkage, "main", &Module);
IRGenFunction mainIGF(*this, mainFn);
if (DebugInfo) {
// Emit at least the return type.
SILParameterInfo paramTy(CanType(BuiltinIntegerType::get(32, Context)),
ParameterConvention::Direct_Unowned);
SILResultInfo retTy(TupleType::getEmpty(Context),
ResultConvention::Unowned);
auto extInfo = SILFunctionType::ExtInfo(AbstractCC::Freestanding,
SILFunctionType::Representation::Thin,
/*noreturn*/ false);
auto fnTy = SILFunctionType::get(nullptr, extInfo,
ParameterConvention::Direct_Unowned,
paramTy, retTy,
Context);
auto silFnTy = SILType::getPrimitiveLocalStorageType(fnTy);
DebugInfo->emitArtificialFunction(mainIGF, mainFn, silFnTy);
}
// Poke argc and argv into variables declared in the Swift stdlib
auto args = mainFn->arg_begin();
auto accessorTy
= llvm::FunctionType::get(Int8PtrTy, {}, /*varArg*/ false);
for (auto varNames : {
// global accessor for Swift.C_ARGC : CInt
std::make_pair("argc", "_TFSsa6C_ARGCVSs5Int32"),
// global accessor for Swift.C_ARGV : UnsafePointer<CString>
std::make_pair("argv", "_TFSsa6C_ARGVGVSs13UnsafePointerVSs7CString_")
}) {
StringRef fnParameterName;
StringRef accessorName;
std::tie(fnParameterName, accessorName) = varNames;
llvm::Value* fnParameter = args++;
fnParameter->setName(fnParameterName);
// Access the address of the global.
auto accessor = Module.getOrInsertFunction(accessorName, accessorTy);
llvm::Value *ptr = mainIGF.Builder.CreateCall(accessor);
// Cast to the type of the parameter we're storing.
ptr = mainIGF.Builder.CreateBitCast(ptr,
fnParameter->getType()->getPointerTo());
mainIGF.Builder.CreateStore(fnParameter, ptr);
}
// Emit Objective-C runtime interop setup for immediate-mode code.
if (ObjCInterop && Opts.UseJIT) {
if (!ObjCClasses.empty()) {
// Emit an initializer for the Objective-C classes.
mainIGF.Builder.CreateCall(emitObjCClassInitializer(*this,ObjCClasses));
}
if (!ObjCCategoryDecls.empty()) {
// Emit an initializer to add declarations from category decls.
mainIGF.Builder.CreateCall(emitObjCCategoryInitializer(*this,
ObjCCategoryDecls));
}
}
// Call the top-level code.
if (topLevelCodeFn)
mainIGF.Builder.CreateCall(topLevelCodeFn);
mainIGF.Builder.CreateRet(mainIGF.Builder.getInt32(0));
}
/// Add the given global value to @llvm.used.
void IRGenModule::addUsedGlobal(llvm::GlobalValue *global) {
assert(!global->isDeclaration() &&
"Only globals with definition can force usage.");
LLVMUsed.push_back(global);
}
/// Add the given global value to the Objective-C class list.
void IRGenModule::addObjCClass(llvm::Constant *classPtr) {
ObjCClasses.push_back(classPtr);
}
/// Emit a global list, i.e. a global constant array holding all of a
/// list of values. Generally these lists are for various LLVM
/// metadata or runtime purposes.
static void emitGlobalList(IRGenModule &IGM, ArrayRef<llvm::WeakVH> handles,
StringRef name, StringRef section,
llvm::GlobalValue::LinkageTypes linkage) {
// Do nothing if the list is empty.
if (handles.empty()) return;
// For global lists that actually get linked (as opposed to notional
// ones like @llvm.used), it's important to set an explicit alignment
// so that the linker doesn't accidentally put padding in the list.
Alignment alignment = IGM.getPointerAlignment();
auto eltTy = IGM.Int8PtrTy;
// We have an array of value handles, but we need an array of constants.
SmallVector<llvm::Constant*, 8> elts;
elts.reserve(handles.size());
for (auto &handle : handles) {
auto elt = cast<llvm::Constant>(&*handle);
elt = llvm::ConstantExpr::getBitCast(elt, eltTy);
elts.push_back(elt);
}
auto varTy = llvm::ArrayType::get(eltTy, elts.size());
auto init = llvm::ConstantArray::get(varTy, elts);
auto var = new llvm::GlobalVariable(IGM.Module, varTy, false, linkage,
init, name);
var->setSection(section);
var->setAlignment(alignment.getValue());
// Mark the variable as used if doesn't have external linkage.
// (Note that we'd specifically like to not put @llvm.used in itself.)
if (llvm::GlobalValue::isLocalLinkage(linkage))
IGM.addUsedGlobal(var);
}
void IRGenModule::emitGlobalLists() {
// Objective-C class references go in a variable with a meaningless
// name but a magic section.
emitGlobalList(*this, ObjCClasses, "objc_classes",
"__DATA, __objc_classlist, regular, no_dead_strip",
llvm::GlobalValue::InternalLinkage);
// So do categories.
emitGlobalList(*this, ObjCCategories, "objc_categories",
"__DATA, __objc_catlist, regular, no_dead_strip",
llvm::GlobalValue::InternalLinkage);
// FIXME: We also emit the class references in a second magic section to make
// sure they are "realized" by the Objective-C runtime before any instances
// are allocated.
emitGlobalList(*this, ObjCClasses, "objc_non_lazy_classes",
"__DATA, __objc_nlclslist, regular, no_dead_strip",
llvm::GlobalValue::InternalLinkage);
// @llvm.used
emitGlobalList(*this, LLVMUsed, "llvm.used", "llvm.metadata",
llvm::GlobalValue::AppendingLinkage);
}
/// Prepare for the emission of a program.
void IRGenModule::prepare() {
// Generate order numbers for the functions in the SIL module that
// correspond to definitions in the LLVM module.
unsigned nextOrderNumber = 0;
for (auto &silFn : SILMod->getFunctions()) {
// Don't bother adding external declarations to the function order.
if (!silFn.isDefinition()) continue;
FunctionOrder.insert(std::make_pair(&silFn, nextOrderNumber++));
}
}
void IRGenModule::emitGlobalTopLevel() {
// Emit global variables.
for (VarDecl *global : SILMod->getGlobals()) {
auto &ti = getTypeInfoForUnlowered(global->getType());
emitGlobalVariable(global, ti);
}
for (SILGlobalVariable &v : SILMod->getSILGlobals())
emitSILGlobalVariable(&v);
// Emit SIL functions.
for (SILFunction &f : *SILMod) {
// Only eagerly emit functions that are externally visible.
if (!isPossiblyUsedExternally(f.getLinkage()))
continue;
emitSILFunction(&f);
}
// Emit witness tables.
for (SILWitnessTable &wt : SILMod->getWitnessTableList()) {
// Try to be lazy about it.
if (!isPossiblyUsedExternally(wt.getLinkage())) {
// Remember that we know how to emit this conformance.
auto lookup =
LazyWitnessTablesByConformance.insert({wt.getConformance(), &wt});
// If we successfully made a new entry, just continue.
if (lookup.second) {
assert(lookup.first->second == &wt);
continue;
}
// Otherwise, we already have an outstanding request for this
// conformance, so go ahead and emit it now.
assert(lookup.first->second == nullptr);
}
emitSILWitnessTable(&wt);
}
// Emit the implicit import of the swift standard libary.
if (DebugInfo) {
std::pair<swift::Identifier, swift::SourceLoc> AccessPath[] = {
{ Context.StdlibModuleName, swift::SourceLoc() }
};
auto Imp = ImportDecl::create(Context,
SILMod->getSwiftModule(),
SourceLoc(),
ImportKind::Module, SourceLoc(),
AccessPath);
DebugInfo->emitImport(Imp);
}
// Emit external definitions used by this module.
for (auto def : Context.ExternalDefinitions) {
emitExternalDefinition(def);
}
}
static void emitLazyTypeMetadata(IRGenModule &IGM, CanType type) {
auto decl = type.getAnyNominal();
assert(decl);
if (auto sd = dyn_cast<StructDecl>(decl)) {
return emitStructMetadata(IGM, sd);
} else if (auto ed = dyn_cast<EnumDecl>(decl)) {
emitEnumMetadata(IGM, ed);
} else if (auto pd = dyn_cast<ProtocolDecl>(decl)) {
IGM.emitProtocolDecl(pd);
} else {
llvm_unreachable("should not have enqueued a class decl here!");
}
}
/// Emit any lazy definitions (of globals or functions or whatever
/// else) that we require.
void IRGenModule::emitLazyDefinitions() {
while (!LazyWitnessTables.empty() ||
!LazyTypeMetadata.empty() ||
!LazyFunctionDefinitions.empty()) {
// Emit any lazy witness tables we require. We do this first
// because it's likely to introduce new uses of lazy functions
// and possibly of type metadata.
while (!LazyWitnessTables.empty()) {
SILWitnessTable *wt = LazyWitnessTables.pop_back_val();
assert(!isPossiblyUsedExternally(wt->getLinkage()) &&
"witness table with externally-visible linkage emitted lazily?");
emitSILWitnessTable(wt);
}
// Emit any lazy type metadata we require.
while (!LazyTypeMetadata.empty()) {
CanType type = LazyTypeMetadata.pop_back_val();
assert(isTypeMetadataEmittedLazily(type));
emitLazyTypeMetadata(*this, type);
}
// Emit any lazy function definitions we require.
while (!LazyFunctionDefinitions.empty()) {
SILFunction *f = LazyFunctionDefinitions.pop_back_val();
assert(!isPossiblyUsedExternally(f->getLinkage()) &&
"function with externally-visible linkage emitted lazily?");
emitSILFunction(f);
}
}
}
/// As a kludge, try to find the linkage of a SILWitnessTable in the current
/// SIL module, falling back to public_external if there is none.
SILLinkage irgen::getProtocolConformanceLinkage(IRGenModule &IGM,
ProtocolConformance *C) {
auto wt = IGM.SILMod->lookUpWitnessTable(C);
if (!wt.first)
return SILLinkage::PublicExternal;
return wt.first->getLinkage();
}
static SILLinkage getSILLinkage(FormalLinkage linkage,
ForDefinition_t forDefinition) {
switch (linkage) {
case FormalLinkage::PublicUnique:
return (forDefinition ? SILLinkage::Public : SILLinkage::PublicExternal);
case FormalLinkage::PublicNonUnique:
// FIXME: any place we have to do this that actually requires
// uniqueness is buggy.
return (forDefinition ? SILLinkage::Shared : SILLinkage::PublicExternal);
case FormalLinkage::HiddenUnique:
return (forDefinition ? SILLinkage::Hidden : SILLinkage::HiddenExternal);
case FormalLinkage::HiddenNonUnique:
return (forDefinition ? SILLinkage::Shared : SILLinkage::HiddenExternal);
case FormalLinkage::Private:
return SILLinkage::Private;
}
llvm_unreachable("bad formal linkage");
}
/// Get SIL-linkage for something that's not required to be visible
/// and doesn't actually need to be uniqued.
static SILLinkage getNonUniqueSILLinkage(FormalLinkage linkage,
ForDefinition_t forDefinition) {
switch (linkage) {
case FormalLinkage::PublicUnique:
case FormalLinkage::PublicNonUnique:
return (forDefinition ? SILLinkage::Shared : SILLinkage::PublicExternal);
case FormalLinkage::HiddenUnique:
case FormalLinkage::HiddenNonUnique:
return (forDefinition ? SILLinkage::Shared : SILLinkage::HiddenExternal);
case FormalLinkage::Private:
return SILLinkage::Private;
}
llvm_unreachable("bad formal linkage");
}
SILLinkage LinkEntity::getLinkage(ForDefinition_t forDefinition) const {
switch (getKind()) {
// Most type metadata depend on the formal linkage of their type.
case Kind::ValueWitnessTable:
case Kind::TypeMetadata:
case Kind::TypeMangling:
return getSILLinkage(getTypeLinkage(getType()), forDefinition);
// ...but we don't actually expose individual value witnesses (right now).
case Kind::ValueWitness:
return getNonUniqueSILLinkage(getTypeLinkage(getType()), forDefinition);
// Foreign type metadata candidates are always shared; the runtime
// does the uniquing.
case Kind::ForeignTypeMetadataCandidate:
return SILLinkage::Shared;
case Kind::WitnessTableOffset:
case Kind::Function:
case Kind::Other:
case Kind::ObjCClass:
case Kind::ObjCMetaclass:
case Kind::SwiftMetaclassStub:
case Kind::FieldOffset:
case Kind::NominalTypeDescriptor:
case Kind::ProtocolDescriptor:
return getSILLinkage(getDeclLinkage(getDecl()), forDefinition);
case Kind::DirectProtocolWitnessTable:
case Kind::LazyProtocolWitnessTableAccessor:
case Kind::DependentProtocolWitnessTableGenerator:
return getProtocolConformanceLinkage();
case Kind::LazyProtocolWitnessTableTemplate:
case Kind::DependentProtocolWitnessTableTemplate:
return SILLinkage::Private;
case Kind::SILFunction:
return getSILFunction()->getLinkage();
case Kind::SILGlobalVariable:
return getSILGlobalVariable()->getLinkage();
}
llvm_unreachable("bad link entity kind");
}
static std::pair<llvm::GlobalValue::LinkageTypes,
llvm::GlobalValue::VisibilityTypes>
getIRLinkage(IRGenModule &IGM,
SILLinkage linkage, ForDefinition_t isDefinition) {
switch (linkage) {
#define RESULT(LINKAGE, VISIBILITY) \
{ llvm::GlobalValue::LINKAGE##Linkage, \
llvm::GlobalValue::VISIBILITY##Visibility }
case SILLinkage::Public: return RESULT(External, Default);
case SILLinkage::Shared: return RESULT(LinkOnceODR, Hidden);
case SILLinkage::Hidden: return RESULT(External, Hidden);
case SILLinkage::Private: return RESULT(Internal, Default);
case SILLinkage::PublicExternal:
if (isDefinition) {
// FIXME: Work around problems linking available_externally symbols in the
// REPL. <rdar://problem/16094902>
if (IGM.Opts.UseJIT)
return RESULT(LinkOnceODR, Default);
return RESULT(AvailableExternally, Default);
}
return RESULT(External, Default);
case SILLinkage::HiddenExternal:
if (isDefinition) {
// FIXME: Work around problems linking available_externally symbols in the
// REPL. <rdar://problem/16094902>
if (IGM.Opts.UseJIT)
return RESULT(LinkOnceODR, Hidden);
return RESULT(AvailableExternally, Hidden);
}
return RESULT(External, Hidden);
}
llvm_unreachable("bad SIL linkage");
}
/// Given that we're going to define a global value but already have a
/// forward-declaration of it, update its linkage.
static void updateLinkageForDefinition(IRGenModule &IGM,
llvm::GlobalValue *global,
const LinkEntity &entity) {
// TODO: there are probably cases where we can avoid redoing the
// entire linkage computation.
auto linkage = getIRLinkage(IGM,
entity.getLinkage(ForDefinition), ForDefinition);
global->setLinkage(linkage.first);
global->setVisibility(linkage.second);
}
LinkInfo LinkInfo::get(IRGenModule &IGM, const LinkEntity &entity,
ForDefinition_t isDefinition) {
LinkInfo result;
entity.mangle(result.Name);
std::tie(result.Linkage, result.Visibility) =
getIRLinkage(IGM, entity.getLinkage(isDefinition), isDefinition);
return result;
}
static bool isPointerTo(llvm::Type *ptrTy, llvm::Type *objTy) {
return cast<llvm::PointerType>(ptrTy)->getElementType() == objTy;
}
/// Get or create an LLVM function with these linkage rules.
llvm::Function *LinkInfo::createFunction(IRGenModule &IGM,
llvm::FunctionType *fnType,
llvm::CallingConv::ID cc,
const llvm::AttributeSet &attrs,
llvm::Function *insertBefore) {
llvm::Function *existing = IGM.Module.getFunction(getName());
if (existing) {
if (isPointerTo(existing->getType(), fnType))
return cast<llvm::Function>(existing);
IGM.error(SourceLoc(),
"program too clever: function collides with existing symbol "
+ getName());
// Note that this will implicitly unique if the .unique name is also taken.
existing->setName(getName() + ".unique");
}
llvm::Function *fn
= llvm::Function::Create(fnType, getLinkage(), getName());
if (insertBefore) {
IGM.Module.getFunctionList().insert(insertBefore, fn);
} else {
IGM.Module.getFunctionList().push_back(fn);
}
fn->setVisibility(getVisibility());
fn->setCallingConv(cc);
if (!attrs.isEmpty())
fn->setAttributes(attrs);
return fn;
}
/// Get or create an LLVM global variable with these linkage rules.
llvm::GlobalVariable *LinkInfo::createVariable(IRGenModule &IGM,
llvm::Type *storageType,
DebugTypeInfo DebugType,
Optional<SILLocation> DebugLoc,
StringRef DebugName) {
llvm::GlobalValue *existing = IGM.Module.getNamedGlobal(getName());
if (existing) {
if (isa<llvm::GlobalVariable>(existing) &&
isPointerTo(existing->getType(), storageType))
return cast<llvm::GlobalVariable>(existing);
IGM.error(SourceLoc(),
"program too clever: variable collides with existing symbol "
+ getName());
// Note that this will implicitly unique if the .unique name is also taken.
existing->setName(getName() + ".unique");
}
llvm::GlobalVariable *var
= new llvm::GlobalVariable(IGM.Module, storageType, /*constant*/ false,
getLinkage(), /*initializer*/ nullptr,
getName());
var->setVisibility(getVisibility());
if (IGM.DebugInfo)
IGM.DebugInfo->
emitGlobalVariableDeclaration(var,
DebugName.empty() ? getName() : DebugName,
getName(), DebugType, DebugLoc);
return var;
}
/// Emit a global declaration.
void IRGenModule::emitGlobalDecl(Decl *D) {
switch (D->getKind()) {
case DeclKind::Extension:
return emitExtension(cast<ExtensionDecl>(D));
case DeclKind::Protocol:
return emitProtocolDecl(cast<ProtocolDecl>(D));
case DeclKind::PatternBinding:
// The global initializations are in SIL.
return;
case DeclKind::Param:
llvm_unreachable("there are no global function parameters");
case DeclKind::Subscript:
llvm_unreachable("there are no global subscript operations");
case DeclKind::EnumCase:
case DeclKind::EnumElement:
llvm_unreachable("there are no global enum elements");
case DeclKind::Constructor:
llvm_unreachable("there are no global constructor");
case DeclKind::Destructor:
llvm_unreachable("there are no global destructor");
case DeclKind::TypeAlias:
case DeclKind::GenericTypeParam:
case DeclKind::AssociatedType:
case DeclKind::IfConfig:
return;
case DeclKind::Enum:
return emitEnumDecl(cast<EnumDecl>(D));
case DeclKind::Struct:
return emitStructDecl(cast<StructDecl>(D));
case DeclKind::Class:
return emitClassDecl(cast<ClassDecl>(D));
// These declarations are only included in the debug info.
case DeclKind::Import:
if (DebugInfo)
DebugInfo->emitImport(cast<ImportDecl>(D));
return;
// We emit these as part of the PatternBindingDecl.
case DeclKind::Var:
return;
case DeclKind::Func:
// Emit local definitions from the function body.
return emitLocalDecls(cast<FuncDecl>(D));
case DeclKind::TopLevelCode:
// All the top-level code will be lowered separately.
return;
// Operator decls aren't needed for IRGen.
case DeclKind::InfixOperator:
case DeclKind::PrefixOperator:
case DeclKind::PostfixOperator:
return;
}
llvm_unreachable("bad decl kind!");
}
void IRGenModule::emitExternalDefinition(Decl *D) {
switch (D->getKind()) {
case DeclKind::Extension:
case DeclKind::PatternBinding:
case DeclKind::EnumCase:
case DeclKind::EnumElement:
case DeclKind::TopLevelCode:
case DeclKind::TypeAlias:
case DeclKind::GenericTypeParam:
case DeclKind::AssociatedType:
case DeclKind::Var:
case DeclKind::Import:
case DeclKind::Subscript:
case DeclKind::Destructor:
case DeclKind::InfixOperator:
case DeclKind::PrefixOperator:
case DeclKind::PostfixOperator:
case DeclKind::IfConfig:
case DeclKind::Param:
llvm_unreachable("Not a valid external definition for IRgen");
case DeclKind::Func:
return emitLocalDecls(cast<FuncDecl>(D));
case DeclKind::Constructor:
return emitLocalDecls(cast<ConstructorDecl>(D));
// No need to eagerly emit Swift metadata for external types.
case DeclKind::Struct:
case DeclKind::Enum:
case DeclKind::Class:
case DeclKind::Protocol:
break;
}
}
Address IRGenModule::getAddrOfSILGlobalVariable(SILGlobalVariable *var,
ForDefinition_t forDefinition) {
LinkEntity entity = LinkEntity::forSILGlobalVariable(var);
// Check whether we've created the global variable already.
// FIXME: We should integrate this into the LinkEntity cache more cleanly.
auto gvar = Module.getGlobalVariable(var->getName(), /*allowInternal*/ true);
if (gvar) {
if (forDefinition) updateLinkageForDefinition(*this, gvar, entity);
return Address(gvar, Alignment(gvar->getAlignment()));
}
LinkInfo link = LinkInfo::get(*this, entity, forDefinition);
auto &ti = getTypeInfo(var->getLoweredType());
// There is no VarDecl for a SILGlobalVariable, and thus also no context.
DeclContext *DeclCtx = nullptr;
DebugTypeInfo DbgTy(var->getLoweredType().getSwiftRValueType(), ti, DeclCtx);
Optional<SILLocation> loc;
if (var->hasLocation())
loc = var->getLocation();
gvar = link.createVariable(*this, ti.StorageType, DbgTy,
loc, var->getName());
// Set the alignment from the TypeInfo.
Address gvarAddr = ti.getAddressForPointer(gvar);
gvar->setAlignment(gvarAddr.getAlignment().getValue());
return gvarAddr;
}
/// Find the address of a (fragile, constant-size) global variable
/// declaration. The address value is always an llvm::GlobalVariable*.
Address IRGenModule::getAddrOfGlobalVariable(VarDecl *var,
ForDefinition_t forDefinition) {
// Check whether we've cached this.
LinkEntity entity = LinkEntity::forNonFunction(var);
llvm::Constant *&entry = GlobalVars[entity];
if (entry) {
llvm::GlobalVariable *gv = cast<llvm::GlobalVariable>(entry);
if (forDefinition) updateLinkageForDefinition(*this, gv, entity);
return Address(gv, Alignment(gv->getAlignment()));
}
const TypeInfo &type = getTypeInfoForUnlowered(var->getType());
// Okay, we need to rebuild it.
LinkInfo link = LinkInfo::get(*this, entity, forDefinition);
DebugTypeInfo DbgTy(var, type);
auto addr = link.createVariable(*this, type.StorageType,
DbgTy, var, var->getName().str());
// Ask the type to give us an Address.
Address result = type.getAddressForPointer(addr);
// Set that alignment back on the global variable.
addr->setAlignment(result.getAlignment().getValue());
// Write this to the cache and return.
entry = addr;
return result;
}
/// Find the entry point for a SIL function, which we assume exists in
/// the module.
llvm::Function *IRGenModule::getAddrOfSILFunction(SILDeclRef fnRef,
ForDefinition_t forDefinition) {
llvm::SmallString<32> name;
fnRef.mangle(name);
SILFunction *fn = SILMod->lookUpFunction(name);
#ifndef NDEBUG
if (!fn) {
assert(!forDefinition &&
"defining a SILFunction that's not in the SILModule?");
auto linkage = fnRef.getLinkage(forDefinition);
auto type = SILMod->Types.getConstantType(fnRef).castTo<SILFunctionType>();
fn = SILFunction::create(*SILMod, linkage, name, type, nullptr,
Nothing, IsNotBare, IsNotTransparent);
}
#endif
return getAddrOfSILFunction(fn, forDefinition);
}
/// Find the entry point for a SIL function.
llvm::Function *IRGenModule::getAddrOfSILFunction(SILFunction *f,
ForDefinition_t forDefinition) {
LinkEntity entity = LinkEntity::forSILFunction(f);
// Check whether we've created the function already.
// FIXME: We should integrate this into the LinkEntity cache more cleanly.
llvm::Function *fn = Module.getFunction(f->getName());
if (fn) {
if (forDefinition) updateLinkageForDefinition(*this, fn, entity);
return fn;
}
bool hasOrderNumber = f->isDefinition();
unsigned orderNumber = ~0U;
llvm::Function *insertBefore = nullptr;
// If the SIL function has a definition, we should have an order
// number for it; make sure to insert it in that position relative
// to other ordered functions.
if (hasOrderNumber) {
auto it = FunctionOrder.find(f);
assert(it != FunctionOrder.end() &&
"no order number for SIL function definition?");
orderNumber = it->second;
if (auto emittedFunctionIterator
= EmittedFunctionsByOrder.findLeastUpperBound(orderNumber))
insertBefore = *emittedFunctionIterator;
// Also, if we have a lazy definition for it, be sure to queue that up.
if (!forDefinition &&
!isPossiblyUsedExternally(f->getLinkage()))
LazyFunctionDefinitions.push_back(f);
}
llvm::AttributeSet attrs;
llvm::FunctionType *fnType = getFunctionType(f->getLoweredFunctionType(),
/*FIXME: shouldn't be required here*/ ResilienceExpansion::Minimal,
ExtraData::None,
attrs);
auto cc = expandAbstractCC(*this, f->getAbstractCC());
LinkInfo link = LinkInfo::get(*this, entity, forDefinition);
fn = link.createFunction(*this, fnType, cc, attrs, insertBefore);
// If we have an order number for this function, set it up as appropriate.
if (hasOrderNumber) {
EmittedFunctionsByOrder.insert(orderNumber, fn);
}
// Unless this is an external reference, emit debug info for it.
// FIXME: Or if this is a witness. DebugInfo doesn't have an interface to
// correctly handle the generic parameters of a witness, which can come from
// both the requirement and witness contexts.
if (DebugInfo && !f->isExternalDeclaration()
&& f->getAbstractCC() != AbstractCC::WitnessMethod)
DebugInfo->emitFunction(f, fn);
return fn;
}
/// Get or create a llvm::GlobalVariable.
///
/// If a definition type is given, the result will always be an
/// llvm::GlobalVariable of that type. Otherwise, the result will
/// have type pointerToDefaultType and may involve bitcasts.
static llvm::Constant *getAddrOfLLVMVariable(IRGenModule &IGM,
llvm::DenseMap<LinkEntity, llvm::Constant*> &globals,
LinkEntity entity,
llvm::Type *definitionType,
llvm::Type *defaultType,
llvm::Type *pointerToDefaultType,
DebugTypeInfo debugType) {
// This function assumes that 'globals' only contains GlobalVariable
// values for the entities that it will look up.
auto &entry = globals[entity];
if (entry) {
auto existing = cast<llvm::GlobalVariable>(entry);
// If we're looking to define something, we may need to replace a
// forward declaration.
if (definitionType) {
assert(entry->getType() == pointerToDefaultType);
updateLinkageForDefinition(IGM, existing, entity);
// If the type is right, we're done.
if (definitionType == defaultType)
return entry;
// Fall out to the case below, clearing the name so that
// createVariable doesn't detect a collision.
entry->setName("");
// Otherwise, we have a previous declaration or definition which
// we need to ensure has the right type.
} else {
return llvm::ConstantExpr::getBitCast(entry, pointerToDefaultType);
}
}
ForDefinition_t forDefinition = (ForDefinition_t) (definitionType != nullptr);
// If we're not defining the object now
if (!definitionType) definitionType = defaultType;
// Create the variable.
LinkInfo link = LinkInfo::get(IGM, entity, forDefinition);
auto var = link.createVariable(IGM, definitionType, debugType);
// If we have an existing entry, destroy it, replacing it with the
// new variable.
if (entry) {
auto existing = cast<llvm::GlobalVariable>(entry);
auto castVar = llvm::ConstantExpr::getBitCast(var, pointerToDefaultType);
existing->replaceAllUsesWith(castVar);
existing->eraseFromParent();
}
// Cache and return.
entry = var;
return var;
}
static llvm::Constant *getAddrOfLLVMVariable(IRGenModule &IGM,
llvm::DenseMap<LinkEntity, llvm::Constant*> &globals,
LinkEntity entity,
ForDefinition_t forDefinition,
llvm::Type *defaultType,
llvm::Type *pointerToDefaultType,
DebugTypeInfo debugType) {
llvm::Type *definitionType = (forDefinition ? defaultType : nullptr);
return getAddrOfLLVMVariable(IGM, globals, entity, definitionType,
defaultType, pointerToDefaultType, debugType);
}
/// Fetch a global reference to the given Objective-C class. The
/// result is of type ObjCClassPtrTy.
llvm::Constant *IRGenModule::getAddrOfObjCClass(ClassDecl *theClass,
ForDefinition_t forDefinition) {
assert(ObjCInterop && "getting address of ObjC class in no-interop mode");
LinkEntity entity = LinkEntity::forObjCClass(theClass);
DebugTypeInfo DbgTy(theClass, getPointerSize(), getPointerAlignment());
auto addr = getAddrOfLLVMVariable(*this, GlobalVars, entity,
forDefinition, ObjCClassStructTy,
ObjCClassPtrTy, DbgTy);
return addr;
}
/// Fetch a global reference to the given Objective-C metaclass.
/// The result is always a GlobalVariable of ObjCClassPtrTy.
llvm::Constant *IRGenModule::getAddrOfObjCMetaclass(ClassDecl *theClass,
ForDefinition_t forDefinition) {
assert(ObjCInterop && "getting address of ObjC metaclass in no-interop mode");
LinkEntity entity = LinkEntity::forObjCMetaclass(theClass);
DebugTypeInfo DbgTy(theClass, getPointerSize(), getPointerAlignment());
auto addr = getAddrOfLLVMVariable(*this, GlobalVars, entity,
forDefinition, ObjCClassStructTy,
ObjCClassPtrTy, DbgTy);
return addr;
}
/// Fetch the declaration of the metaclass stub for the given class type.
/// The result is always a GlobalVariable of ObjCClassPtrTy.
llvm::Constant *IRGenModule::getAddrOfSwiftMetaclassStub(ClassDecl *theClass,
ForDefinition_t forDefinition) {
assert(ObjCInterop && "getting address of metaclass stub in no-interop mode");
LinkEntity entity = LinkEntity::forSwiftMetaclassStub(theClass);
DebugTypeInfo DbgTy(theClass, getPointerSize(), getPointerAlignment());
auto addr = getAddrOfLLVMVariable(*this, GlobalVars, entity,
forDefinition, ObjCClassStructTy,
ObjCClassPtrTy, DbgTy);
return addr;
}
/// Fetch the declaration of a metaclass object. This performs either
/// getAddrOfSwiftMetaclassStub or getAddrOfObjCMetaclass, depending
/// on whether the class is published as an ObjC class.
llvm::Constant *IRGenModule::getAddrOfMetaclassObject(ClassDecl *decl,
ForDefinition_t forDefinition) {
if (decl->isObjC() || decl->hasClangNode()) {
return getAddrOfObjCMetaclass(decl, forDefinition);
} else {
return getAddrOfSwiftMetaclassStub(decl, forDefinition);
}
}
/// Fetch the declaration of the metadata (or metadata template) for a
/// class.
///
/// If the definition type is specified, the result will always be a
/// GlobalVariable of the given type, which may not be at the
/// canonical address point for a type metadata.
///
/// If the definition type is not specified, then:
/// - if the metadata is indirect, then the result will not be adjusted
/// and it will have the type pointer-to-T, where T is the type
/// of a direct metadata;
/// - if the metadata is a pattern, then the result will not be
/// adjusted and it will have TypeMetadataPatternPtrTy;
/// - otherwise it will be adjusted to the canonical address point
/// for a type metadata and it will have type TypeMetadataPtrTy.
llvm::Constant *IRGenModule::getAddrOfTypeMetadata(CanType concreteType,
bool isIndirect,
bool isPattern,
llvm::Type *definitionType) {
assert(isPattern || !isa<UnboundGenericType>(concreteType));
llvm::Type *defaultVarTy;
llvm::Type *defaultVarPtrTy;
unsigned adjustmentIndex;
ClassDecl *ObjCClass = nullptr;
// Patterns use the pattern type and no adjustment.
if (isPattern) {
defaultVarTy = TypeMetadataPatternStructTy;
defaultVarPtrTy = TypeMetadataPatternPtrTy;
adjustmentIndex = MetadataAdjustmentIndex::None;
// Objective-C classes use the generic metadata type and need no adjustment.
} else if (isa<ClassType>(concreteType) &&
!hasKnownSwiftMetadata(*this,
cast<ClassType>(concreteType)->getDecl())) {
defaultVarTy = TypeMetadataStructTy;
defaultVarPtrTy = TypeMetadataPtrTy;
adjustmentIndex = MetadataAdjustmentIndex::None;
ObjCClass = cast<ClassType>(concreteType)->getDecl();
// Class direct metadata use the heap type and require a two-word
// adjustment (due to the heap-metadata header).
} else if (isa<ClassType>(concreteType) ||
isa<BoundGenericClassType>(concreteType)) {
defaultVarTy = FullHeapMetadataStructTy;
defaultVarPtrTy = FullHeapMetadataPtrTy;
adjustmentIndex = MetadataAdjustmentIndex::Class;
// All other non-pattern direct metadata use the full type and
// require an adjustment.
} else {
defaultVarTy = FullTypeMetadataStructTy;
defaultVarPtrTy = FullTypeMetadataPtrTy;
adjustmentIndex = MetadataAdjustmentIndex::ValueType;
}
// If this is a use, and the type metadata is emitted lazily,
// trigger lazy emission of the metadata.
if (!definitionType && isTypeMetadataEmittedLazily(concreteType)) {
// Add it to the queue if it hasn't already been put there.
if (LazilyEmittedTypeMetadata.insert(concreteType))
LazyTypeMetadata.push_back(concreteType);
}
// When indirect, this is always a pointer variable and has no
// adjustment.
if (isIndirect) {
defaultVarTy = defaultVarPtrTy;
defaultVarPtrTy = defaultVarTy->getPointerTo();
adjustmentIndex = MetadataAdjustmentIndex::None;
}
LinkEntity entity
= ObjCClass? LinkEntity::forObjCClass(ObjCClass)
: LinkEntity::forTypeMetadata(concreteType, isIndirect,
isPattern);
auto DbgTy = ObjCClass
? DebugTypeInfo(ObjCClass, getPointerSize(), getPointerAlignment())
: DebugTypeInfo(MetatypeType::get(concreteType), 0, 1, nullptr);
auto addr = getAddrOfLLVMVariable(*this, GlobalVars, entity,
definitionType, defaultVarTy,
defaultVarPtrTy, DbgTy);
// Do an adjustment if necessary.
if (adjustmentIndex && !definitionType) {
llvm::Constant *indices[] = {
llvm::ConstantInt::get(Int32Ty, 0),
llvm::ConstantInt::get(Int32Ty, adjustmentIndex)
};
addr = llvm::ConstantExpr::getInBoundsGetElementPtr(addr, indices);
}
return addr;
}
/// Return the address of a foreign-type metadata candidate. There is no
/// single translation unit which can uniquely emit foreign-type metadata,
/// and we don't want to force the dynamic linker to eagerly unique them
/// by symbol name, so instead we emit a "candidate" metadata and ask
/// the runtime to unique them.
llvm::Constant *
IRGenModule::getAddrOfForeignTypeMetadataCandidate(CanType type) {
// What we save in GlobalVars is actually the offsetted value.
auto entity = LinkEntity::forForeignTypeMetadataCandidate(type);
auto &entry = GlobalVars[entity];
if (entry) return entry;
// Compute the constant initializer and the offset of the type
// metadata candidate within it.
Size addressPoint;
auto init = emitForeignTypeMetadataInitializer(*this, type, addressPoint);
// Create the global variable.
LinkInfo link = LinkInfo::get(*this, entity, ForDefinition);
auto var = link.createVariable(*this, init->getType());
var->setInitializer(init);
// Apply the offset.
llvm::Constant *result = var;
result = llvm::ConstantExpr::getBitCast(result, Int8PtrTy);
result = llvm::ConstantExpr::getInBoundsGetElementPtr(result,
getSize(addressPoint));
result = llvm::ConstantExpr::getBitCast(result, TypeMetadataPtrTy);
// Only remember the offset.
entry = result;
return result;
}
/// Return the address of a nominal type descriptor. Right now, this
/// must always be for purposes of defining it.
llvm::Constant *IRGenModule::getAddrOfNominalTypeDescriptor(NominalTypeDecl *D,
llvm::Type *definitionType) {
assert(definitionType && "not defining nominal type descriptor?");
auto entity = LinkEntity::forNominalTypeDescriptor(D);
return getAddrOfLLVMVariable(*this, GlobalVars, entity,
definitionType, definitionType,
definitionType->getPointerTo(),
DebugTypeInfo());
}
llvm::Constant *IRGenModule::getAddrOfProtocolDescriptor(ProtocolDecl *D,
ForDefinition_t forDefinition) {
if (D->isObjC())
return getAddrOfObjCProtocolRecord(D, forDefinition);
auto entity = LinkEntity::forProtocolDescriptor(D);
auto ty = ProtocolDescriptorStructTy;
return getAddrOfLLVMVariable(*this, GlobalVars, entity,
forDefinition, ty, ty->getPointerTo(),
DebugTypeInfo());
}
/// Fetch the declaration of the ivar initializer for the given class.
Optional<llvm::Function*> IRGenModule::getAddrOfObjCIVarInitDestroy(
ClassDecl *cd,
bool isDestroyer,
ForDefinition_t forDefinition) {
SILDeclRef silRef(cd,
isDestroyer? SILDeclRef::Kind::IVarDestroyer
: SILDeclRef::Kind::IVarInitializer,
ResilienceExpansion::Minimal,
SILDeclRef::ConstructAtNaturalUncurryLevel,
/*isForeign=*/true);
llvm::SmallString<64> ivarInitDestroyNameBuffer;
auto name = silRef.mangle(ivarInitDestroyNameBuffer);
// Find the SILFunction for the ivar initializer or destroyer.
if (auto silFn = SILMod->lookUpFunction(name)) {
return getAddrOfSILFunction(silFn, forDefinition);
}
return Nothing;
}
/// Returns the address of a value-witness function.
llvm::Function *IRGenModule::getAddrOfValueWitness(CanType abstractType,
ValueWitness index,
ForDefinition_t forDefinition) {
// We shouldn't emit value witness symbols for generic type instances.
assert(!isa<BoundGenericType>(abstractType) &&
"emitting value witness for generic type instance?!");
LinkEntity entity = LinkEntity::forValueWitness(abstractType, index);
llvm::Function *&entry = GlobalFuncs[entity];
if (entry) {
if (forDefinition) updateLinkageForDefinition(*this, entry, entity);
return entry;
}
// Find the appropriate function type.
llvm::FunctionType *fnType =
cast<llvm::FunctionType>(
cast<llvm::PointerType>(getValueWitnessTy(index))
->getElementType());
LinkInfo link = LinkInfo::get(*this, entity, forDefinition);
entry = link.createFunction(*this, fnType, RuntimeCC, llvm::AttributeSet());
return entry;
}
/// Returns the address of a value-witness table. If a definition
/// type is provided, the table is created with that type; the return
/// value will be an llvm::GlobalVariable. Otherwise, the result will
/// have type WitnessTablePtrTy.
llvm::Constant *IRGenModule::getAddrOfValueWitnessTable(CanType concreteType,
llvm::Type *definitionType) {
LinkEntity entity = LinkEntity::forValueWitnessTable(concreteType);
DebugTypeInfo DbgTy(concreteType, getPointerSize(), getPointerAlignment(),
nullptr);
return getAddrOfLLVMVariable(*this, GlobalVars, entity, definitionType,
WitnessTableTy, WitnessTablePtrTy, DbgTy);
}
static Address getAddrOfSimpleVariable(IRGenModule &IGM,
llvm::DenseMap<LinkEntity, llvm::Constant*> &cache,
LinkEntity entity,
llvm::Type *type,
Alignment alignment,
ForDefinition_t forDefinition) {
// Check whether it's already cached.
llvm::Constant *&entry = cache[entity];
if (entry) {
auto existing = cast<llvm::GlobalVariable>(entry);
assert(alignment == Alignment(existing->getAlignment()));
if (forDefinition) updateLinkageForDefinition(IGM, existing, entity);
return Address(entry, alignment);
}
// Otherwise, we need to create it.
LinkInfo link = LinkInfo::get(IGM, entity, forDefinition);
auto addr = link.createVariable(IGM, type);
addr->setConstant(true);
addr->setAlignment(alignment.getValue());
entry = addr;
return Address(addr, alignment);
}
/// getAddrOfWitnessTableOffset - Get the address of the global
/// variable which contains an offset within a witness table for the
/// value associated with the given function.
Address IRGenModule::getAddrOfWitnessTableOffset(SILDeclRef code,
ForDefinition_t forDefinition) {
LinkEntity entity =
LinkEntity::forWitnessTableOffset(code.getDecl(),
code.getResilienceExpansion(),
code.uncurryLevel);
return getAddrOfSimpleVariable(*this, GlobalVars, entity,
SizeTy, getPointerAlignment(),
forDefinition);
}
/// getAddrOfWitnessTableOffset - Get the address of the global
/// variable which contains an offset within a witness table for the
/// value associated with the given member variable..
Address IRGenModule::getAddrOfWitnessTableOffset(VarDecl *field,
ForDefinition_t forDefinition) {
LinkEntity entity =
LinkEntity::forWitnessTableOffset(field, ResilienceExpansion::Minimal, 0);
return ::getAddrOfSimpleVariable(*this, GlobalVars, entity,
SizeTy, getPointerAlignment(),
forDefinition);
}
/// getAddrOfFieldOffset - Get the address of the global variable
/// which contains an offset to apply to either an object (if direct)
/// or a metadata object in order to find an offset to apply to an
/// object (if indirect).
///
/// The result is always a GlobalVariable.
Address IRGenModule::getAddrOfFieldOffset(VarDecl *var, bool isIndirect,
ForDefinition_t forDefinition) {
LinkEntity entity = LinkEntity::forFieldOffset(var, isIndirect);
return getAddrOfSimpleVariable(*this, GlobalVars, entity,
SizeTy, getPointerAlignment(),
forDefinition);
}
static bool protocolExtensionRequiresCategory(ProtocolDecl *protocol,
ProtocolConformance *conformance) {
if (protocol->isObjC())
return true;
for (auto &inherited : conformance->getInheritedConformances())
if (protocolExtensionRequiresCategory(inherited.first, inherited.second))
return true;
return false;
}
/// Emit a type extension.
void IRGenModule::emitExtension(ExtensionDecl *ext) {
ClassDecl *origClass = ext->getExtendedType()->getClassOrBoundGenericClass();
for (Decl *member : ext->getMembers()) {
switch (member->getKind()) {
case DeclKind::Import:
case DeclKind::EnumCase:
case DeclKind::EnumElement:
case DeclKind::TopLevelCode:
case DeclKind::Protocol:
case DeclKind::Extension:
case DeclKind::Destructor:
case DeclKind::InfixOperator:
case DeclKind::PrefixOperator:
case DeclKind::PostfixOperator:
case DeclKind::Param:
llvm_unreachable("decl not allowed in extension!");
// PatternBindingDecls don't really make sense here, but we
// produce one as a side-effect of parsing a var property.
// Just ignore it.
case DeclKind::PatternBinding:
continue;
// Active members of the IfConfig block are handled separately.
case DeclKind::IfConfig:
continue;
case DeclKind::Subscript:
// Getter/setter will be handled separately.
continue;
case DeclKind::TypeAlias:
case DeclKind::GenericTypeParam:
case DeclKind::AssociatedType:
continue;
case DeclKind::Enum:
emitEnumDecl(cast<EnumDecl>(member));
continue;
case DeclKind::Struct:
emitStructDecl(cast<StructDecl>(member));
continue;
case DeclKind::Class:
emitClassDecl(cast<ClassDecl>(member));
continue;
case DeclKind::Var: {
auto var = cast<VarDecl>(member);
if (!var->hasStorage())
// Getter/setter will be handled separately.
continue;
if (var->isStatic() && !origClass)
continue;
llvm_unreachable("decl not allowed in extension!");
}
case DeclKind::Func:
emitLocalDecls(cast<FuncDecl>(member));
continue;
case DeclKind::Constructor:
emitLocalDecls(cast<ConstructorDecl>(member));
continue;
}
llvm_unreachable("bad extension member kind");
}
// If the original class is ObjC, or the extension either introduces a
// conformance to an ObjC protocol or introduces a method that requires an
// Objective-C entry point, generate a category.
if (!origClass)
return;
bool needsCategory = origClass->isObjC();
if (!needsCategory) {
for (unsigned i = 0, size = ext->getProtocols().size(); i < size; ++i)
if (protocolExtensionRequiresCategory(ext->getProtocols()[i],
ext->getConformances()[i])) {
needsCategory = true;
break;
}
}
if (!needsCategory) {
for (auto member : ext->getMembers()) {
if (auto func = dyn_cast<FuncDecl>(member)) {
if (requiresObjCMethodDescriptor(func)) {
needsCategory = true;
break;
}
continue;
}
if (auto constructor = dyn_cast<ConstructorDecl>(member)) {
if (requiresObjCMethodDescriptor(constructor)) {
needsCategory = true;
break;
}
continue;
}
if (auto var = dyn_cast<VarDecl>(member)) {
if (requiresObjCPropertyDescriptor(*this, var)) {
// Don't emit getters/setters for @NSManagedAttr properties.
// FIXME: We should still emit property metadata.
if (var->getAttrs().hasAttribute<NSManagedAttr>())
break;
needsCategory = true;
break;
}
continue;
}
if (auto subscript = dyn_cast<SubscriptDecl>(member)) {
if (requiresObjCSubscriptDescriptor(*this, subscript)) {
needsCategory = true;
break;
}
continue;
}
}
}
if (needsCategory) {
llvm::Constant *category = emitCategoryData(*this, ext);
category = llvm::ConstantExpr::getBitCast(category, Int8PtrTy);
ObjCCategories.push_back(category);
ObjCCategoryDecls.push_back(ext);
}
}
/// Create an allocation on the stack.
Address IRGenFunction::createAlloca(llvm::Type *type,
Alignment alignment,
const llvm::Twine &name) {
llvm::AllocaInst *alloca = new llvm::AllocaInst(type, name, AllocaIP);
alloca->setAlignment(alignment.getValue());
return Address(alloca, alignment);
}
/// Get or create a global string constant.
///
/// \returns an i8* with a null terminator; note that embedded nulls
/// are okay
llvm::Constant *IRGenModule::getAddrOfGlobalString(StringRef data) {
// Check whether this string already exists.
auto &entry = GlobalStrings[data];
if (entry) return entry;
// If not, create it. This implicitly adds a trailing null.
auto init = llvm::ConstantDataArray::getString(LLVMContext, data);
auto global = new llvm::GlobalVariable(Module, init->getType(), true,
llvm::GlobalValue::PrivateLinkage,
init);
global->setUnnamedAddr(true);
// Drill down to make an i8*.
auto zero = llvm::ConstantInt::get(SizeTy, 0);
llvm::Constant *indices[] = { zero, zero };
auto address = llvm::ConstantExpr::getInBoundsGetElementPtr(global, indices);
// Cache and return.
entry = address;
return address;
}
/// Get or create a global UTF-16 string constant.
///
/// \returns an i16* with a null terminator; note that embedded nulls
/// are okay
llvm::Constant *IRGenModule::getAddrOfGlobalUTF16String(StringRef utf8) {
// Check whether this string already exists.
auto &entry = GlobalUTF16Strings[utf8];
if (entry) return entry;
// If not, first transcode it to UTF16.
SmallVector<UTF16, 128> buffer(utf8.size() + 1); // +1 for ending nulls.
const UTF8 *fromPtr = (const UTF8 *) utf8.data();
UTF16 *toPtr = &buffer[0];
(void) ConvertUTF8toUTF16(&fromPtr, fromPtr + utf8.size(),
&toPtr, toPtr + utf8.size(),
strictConversion);
// The length of the transcoded string in UTF-8 code points.
size_t utf16Length = toPtr - &buffer[0];
// Null-terminate the UTF-16 string.
*toPtr = 0;
ArrayRef<UTF16> utf16(&buffer[0], utf16Length + 1);
auto init = llvm::ConstantDataArray::get(LLVMContext, utf16);
auto global = new llvm::GlobalVariable(Module, init->getType(), true,
llvm::GlobalValue::PrivateLinkage,
init);
global->setUnnamedAddr(true);
// Drill down to make an i16*.
auto zero = llvm::ConstantInt::get(SizeTy, 0);
llvm::Constant *indices[] = { zero, zero };
auto address = llvm::ConstantExpr::getInBoundsGetElementPtr(global, indices);
// Cache and return.
entry = address;
return address;
}
/// Mangle the name of a type.
StringRef IRGenModule::mangleType(CanType type, SmallVectorImpl<char> &buffer) {
LinkEntity::forTypeMangling(type).mangle(buffer);
return StringRef(buffer.data(), buffer.size());
}
/// Is the given declaration resilient?
bool IRGenModule::isResilient(Decl *theDecl, ResilienceScope scope) {
// Classes defined by Clang are resilient.
if (auto theClass = dyn_cast<ClassDecl>(theDecl)) {
return theClass->hasClangNode();
}
return false;
}
/// Look up the address of a witness table.
///
/// TODO: This needs to take a flag for the access mode of the witness table,
/// which may be direct, lazy, or a runtime instantiation template.
/// TODO: Use name from witness table here to lookup witness table instead of
/// recomputing it.
llvm::Constant*
IRGenModule::getAddrOfWitnessTable(const NormalProtocolConformance *C,
llvm::Type *storageTy) {
// If this is a non-definition use, we may need to force a lazy
// conformance to be emitted.
if (!storageTy) {
// Eagerly try to map the conformance to null to mark that we need it.
auto lookup = LazyWitnessTablesByConformance.insert({C, nullptr});
// If that didn't succeed because there's an existing entry, and
// the existing entry is pointing to an implementation, enqueue
// that implementation, then clear out the entry so that we don't
// try to enqueue it multiple times.
if (!lookup.second) {
SILWitnessTable *&entry = lookup.first->second;
if (entry != nullptr) {
LazyWitnessTables.push_back(entry);
entry = nullptr;
}
} else {
assert(lookup.first->second == nullptr);
}
}
auto entity = LinkEntity::forDirectProtocolWitnessTable(
const_cast<NormalProtocolConformance*>(C), *this);
return getAddrOfLLVMVariable(*this, GlobalVars, entity,
storageTy, WitnessTableTy, WitnessTablePtrTy,
DebugTypeInfo());
}
Reference in New Issue View Git Blame Copy Permalink