bolt/deps/llvm-18.1.8/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
2025-02-14 19:21:04 +01:00

1785 lines
67 KiB
C++

//===------ MachOPlatform.cpp - Utilities for executing MachO in Orc ------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/Orc/MachOPlatform.h"
#include "llvm/BinaryFormat/MachO.h"
#include "llvm/ExecutionEngine/JITLink/MachO.h"
#include "llvm/ExecutionEngine/JITLink/aarch64.h"
#include "llvm/ExecutionEngine/JITLink/x86_64.h"
#include "llvm/ExecutionEngine/Orc/DebugUtils.h"
#include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
#include "llvm/ExecutionEngine/Orc/LookupAndRecordAddrs.h"
#include "llvm/ExecutionEngine/Orc/MachOBuilder.h"
#include "llvm/ExecutionEngine/Orc/Shared/ObjectFormats.h"
#include "llvm/Support/BinaryByteStream.h"
#include "llvm/Support/Debug.h"
#include <optional>
#define DEBUG_TYPE "orc"
using namespace llvm;
using namespace llvm::orc;
using namespace llvm::orc::shared;
namespace llvm {
namespace orc {
namespace shared {
using SPSMachOJITDylibDepInfo = SPSTuple<bool, SPSSequence<SPSExecutorAddr>>;
using SPSMachOJITDylibDepInfoMap =
SPSSequence<SPSTuple<SPSExecutorAddr, SPSMachOJITDylibDepInfo>>;
class SPSMachOExecutorSymbolFlags;
template <>
class SPSSerializationTraits<SPSMachOJITDylibDepInfo,
MachOPlatform::MachOJITDylibDepInfo> {
public:
static size_t size(const MachOPlatform::MachOJITDylibDepInfo &DDI) {
return SPSMachOJITDylibDepInfo::AsArgList::size(DDI.Sealed, DDI.DepHeaders);
}
static bool serialize(SPSOutputBuffer &OB,
const MachOPlatform::MachOJITDylibDepInfo &DDI) {
return SPSMachOJITDylibDepInfo::AsArgList::serialize(OB, DDI.Sealed,
DDI.DepHeaders);
}
static bool deserialize(SPSInputBuffer &IB,
MachOPlatform::MachOJITDylibDepInfo &DDI) {
return SPSMachOJITDylibDepInfo::AsArgList::deserialize(IB, DDI.Sealed,
DDI.DepHeaders);
}
};
template <>
class SPSSerializationTraits<SPSMachOExecutorSymbolFlags,
MachOPlatform::MachOExecutorSymbolFlags> {
private:
using UT = std::underlying_type_t<MachOPlatform::MachOExecutorSymbolFlags>;
public:
static size_t size(const MachOPlatform::MachOExecutorSymbolFlags &SF) {
return sizeof(UT);
}
static bool serialize(SPSOutputBuffer &OB,
const MachOPlatform::MachOExecutorSymbolFlags &SF) {
return SPSArgList<UT>::serialize(OB, static_cast<UT>(SF));
}
static bool deserialize(SPSInputBuffer &IB,
MachOPlatform::MachOExecutorSymbolFlags &SF) {
UT Tmp;
if (!SPSArgList<UT>::deserialize(IB, Tmp))
return false;
SF = static_cast<MachOPlatform::MachOExecutorSymbolFlags>(Tmp);
return true;
}
};
} // namespace shared
} // namespace orc
} // namespace llvm
namespace {
using SPSRegisterSymbolsArgs =
SPSArgList<SPSExecutorAddr,
SPSSequence<SPSTuple<SPSExecutorAddr, SPSExecutorAddr,
SPSMachOExecutorSymbolFlags>>>;
std::unique_ptr<jitlink::LinkGraph> createPlatformGraph(MachOPlatform &MOP,
std::string Name) {
unsigned PointerSize;
llvm::endianness Endianness;
const auto &TT = MOP.getExecutionSession().getTargetTriple();
switch (TT.getArch()) {
case Triple::aarch64:
case Triple::x86_64:
PointerSize = 8;
Endianness = llvm::endianness::little;
break;
default:
llvm_unreachable("Unrecognized architecture");
}
return std::make_unique<jitlink::LinkGraph>(std::move(Name), TT, PointerSize,
Endianness,
jitlink::getGenericEdgeKindName);
}
// Creates a Bootstrap-Complete LinkGraph to run deferred actions.
class MachOPlatformCompleteBootstrapMaterializationUnit
: public MaterializationUnit {
public:
using SymbolTableVector =
SmallVector<std::tuple<ExecutorAddr, ExecutorAddr,
MachOPlatform::MachOExecutorSymbolFlags>>;
MachOPlatformCompleteBootstrapMaterializationUnit(
MachOPlatform &MOP, StringRef PlatformJDName,
SymbolStringPtr CompleteBootstrapSymbol, SymbolTableVector SymTab,
shared::AllocActions DeferredAAs, ExecutorAddr MachOHeaderAddr,
ExecutorAddr PlatformBootstrap, ExecutorAddr PlatformShutdown,
ExecutorAddr RegisterJITDylib, ExecutorAddr DeregisterJITDylib,
ExecutorAddr RegisterObjectSymbolTable,
ExecutorAddr DeregisterObjectSymbolTable)
: MaterializationUnit(
{{{CompleteBootstrapSymbol, JITSymbolFlags::None}}, nullptr}),
MOP(MOP), PlatformJDName(PlatformJDName),
CompleteBootstrapSymbol(std::move(CompleteBootstrapSymbol)),
SymTab(std::move(SymTab)), DeferredAAs(std::move(DeferredAAs)),
MachOHeaderAddr(MachOHeaderAddr), PlatformBootstrap(PlatformBootstrap),
PlatformShutdown(PlatformShutdown), RegisterJITDylib(RegisterJITDylib),
DeregisterJITDylib(DeregisterJITDylib),
RegisterObjectSymbolTable(RegisterObjectSymbolTable),
DeregisterObjectSymbolTable(DeregisterObjectSymbolTable) {}
StringRef getName() const override {
return "MachOPlatformCompleteBootstrap";
}
void materialize(std::unique_ptr<MaterializationResponsibility> R) override {
using namespace jitlink;
auto G = createPlatformGraph(MOP, "<OrcRTCompleteBootstrap>");
auto &PlaceholderSection =
G->createSection("__orc_rt_cplt_bs", MemProt::Read);
auto &PlaceholderBlock =
G->createZeroFillBlock(PlaceholderSection, 1, ExecutorAddr(), 1, 0);
G->addDefinedSymbol(PlaceholderBlock, 0, *CompleteBootstrapSymbol, 1,
Linkage::Strong, Scope::Hidden, false, true);
// Reserve space for the stolen actions, plus two extras.
G->allocActions().reserve(DeferredAAs.size() + 3);
// 1. Bootstrap the platform support code.
G->allocActions().push_back(
{cantFail(WrapperFunctionCall::Create<SPSArgList<>>(PlatformBootstrap)),
cantFail(
WrapperFunctionCall::Create<SPSArgList<>>(PlatformShutdown))});
// 2. Register the platform JITDylib.
G->allocActions().push_back(
{cantFail(WrapperFunctionCall::Create<
SPSArgList<SPSString, SPSExecutorAddr>>(
RegisterJITDylib, PlatformJDName, MachOHeaderAddr)),
cantFail(WrapperFunctionCall::Create<SPSArgList<SPSExecutorAddr>>(
DeregisterJITDylib, MachOHeaderAddr))});
// 3. Register deferred symbols.
G->allocActions().push_back(
{cantFail(WrapperFunctionCall::Create<SPSRegisterSymbolsArgs>(
RegisterObjectSymbolTable, MachOHeaderAddr, SymTab)),
cantFail(WrapperFunctionCall::Create<SPSRegisterSymbolsArgs>(
DeregisterObjectSymbolTable, MachOHeaderAddr, SymTab))});
// 4. Add the deferred actions to the graph.
std::move(DeferredAAs.begin(), DeferredAAs.end(),
std::back_inserter(G->allocActions()));
MOP.getObjectLinkingLayer().emit(std::move(R), std::move(G));
}
void discard(const JITDylib &JD, const SymbolStringPtr &Sym) override {}
private:
MachOPlatform &MOP;
StringRef PlatformJDName;
SymbolStringPtr CompleteBootstrapSymbol;
SymbolTableVector SymTab;
shared::AllocActions DeferredAAs;
ExecutorAddr MachOHeaderAddr;
ExecutorAddr PlatformBootstrap;
ExecutorAddr PlatformShutdown;
ExecutorAddr RegisterJITDylib;
ExecutorAddr DeregisterJITDylib;
ExecutorAddr RegisterObjectSymbolTable;
ExecutorAddr DeregisterObjectSymbolTable;
};
static StringRef ObjCRuntimeObjectSectionsData[] = {
MachOObjCCatListSectionName, MachOObjCClassListSectionName,
MachOObjCClassRefsSectionName, MachOObjCConstSectionName,
MachOObjCDataSectionName, MachOObjCSelRefsSectionName};
static StringRef ObjCRuntimeObjectSectionsText[] = {
MachOObjCClassNameSectionName, MachOObjCMethNameSectionName,
MachOObjCMethTypeSectionName, MachOSwift5TypesSectionName,
MachOSwift5TypeRefSectionName, MachOSwift5FieldMetadataSectionName,
MachOSwift5EntrySectionName, MachOSwift5ProtoSectionName,
MachOSwift5ProtosSectionName};
static StringRef ObjCRuntimeObjectSectionName =
"__llvm_jitlink_ObjCRuntimeRegistrationObject";
static StringRef ObjCImageInfoSymbolName =
"__llvm_jitlink_macho_objc_imageinfo";
struct ObjCImageInfoFlags {
uint16_t SwiftABIVersion;
uint16_t SwiftVersion;
bool HasCategoryClassProperties;
bool HasSignedObjCClassROs;
static constexpr uint32_t SIGNED_CLASS_RO = (1 << 4);
static constexpr uint32_t HAS_CATEGORY_CLASS_PROPERTIES = (1 << 6);
explicit ObjCImageInfoFlags(uint32_t RawFlags) {
HasSignedObjCClassROs = RawFlags & SIGNED_CLASS_RO;
HasCategoryClassProperties = RawFlags & HAS_CATEGORY_CLASS_PROPERTIES;
SwiftABIVersion = (RawFlags >> 8) & 0xFF;
SwiftVersion = (RawFlags >> 16) & 0xFFFF;
}
uint32_t rawFlags() const {
uint32_t Result = 0;
if (HasCategoryClassProperties)
Result |= HAS_CATEGORY_CLASS_PROPERTIES;
if (HasSignedObjCClassROs)
Result |= SIGNED_CLASS_RO;
Result |= (SwiftABIVersion << 8);
Result |= (SwiftVersion << 16);
return Result;
}
};
} // end anonymous namespace
namespace llvm {
namespace orc {
Expected<std::unique_ptr<MachOPlatform>> MachOPlatform::Create(
ExecutionSession &ES, ObjectLinkingLayer &ObjLinkingLayer,
JITDylib &PlatformJD, std::unique_ptr<DefinitionGenerator> OrcRuntime,
HeaderOptions PlatformJDOpts, MachOHeaderMUBuilder BuildMachOHeaderMU,
std::optional<SymbolAliasMap> RuntimeAliases) {
// If the target is not supported then bail out immediately.
if (!supportedTarget(ES.getTargetTriple()))
return make_error<StringError>("Unsupported MachOPlatform triple: " +
ES.getTargetTriple().str(),
inconvertibleErrorCode());
auto &EPC = ES.getExecutorProcessControl();
// Create default aliases if the caller didn't supply any.
if (!RuntimeAliases)
RuntimeAliases = standardPlatformAliases(ES);
// Define the aliases.
if (auto Err = PlatformJD.define(symbolAliases(std::move(*RuntimeAliases))))
return std::move(Err);
// Add JIT-dispatch function support symbols.
if (auto Err = PlatformJD.define(
absoluteSymbols({{ES.intern("___orc_rt_jit_dispatch"),
{EPC.getJITDispatchInfo().JITDispatchFunction,
JITSymbolFlags::Exported}},
{ES.intern("___orc_rt_jit_dispatch_ctx"),
{EPC.getJITDispatchInfo().JITDispatchContext,
JITSymbolFlags::Exported}}})))
return std::move(Err);
// Create the instance.
Error Err = Error::success();
auto P = std::unique_ptr<MachOPlatform>(new MachOPlatform(
ES, ObjLinkingLayer, PlatformJD, std::move(OrcRuntime),
std::move(PlatformJDOpts), std::move(BuildMachOHeaderMU), Err));
if (Err)
return std::move(Err);
return std::move(P);
}
Expected<std::unique_ptr<MachOPlatform>>
MachOPlatform::Create(ExecutionSession &ES, ObjectLinkingLayer &ObjLinkingLayer,
JITDylib &PlatformJD, const char *OrcRuntimePath,
HeaderOptions PlatformJDOpts,
MachOHeaderMUBuilder BuildMachOHeaderMU,
std::optional<SymbolAliasMap> RuntimeAliases) {
// Create a generator for the ORC runtime archive.
auto OrcRuntimeArchiveGenerator =
StaticLibraryDefinitionGenerator::Load(ObjLinkingLayer, OrcRuntimePath);
if (!OrcRuntimeArchiveGenerator)
return OrcRuntimeArchiveGenerator.takeError();
return Create(ES, ObjLinkingLayer, PlatformJD,
std::move(*OrcRuntimeArchiveGenerator),
std::move(PlatformJDOpts), std::move(BuildMachOHeaderMU),
std::move(RuntimeAliases));
}
Error MachOPlatform::setupJITDylib(JITDylib &JD) {
return setupJITDylib(JD, /*Opts=*/{});
}
Error MachOPlatform::setupJITDylib(JITDylib &JD, HeaderOptions Opts) {
if (auto Err = JD.define(BuildMachOHeaderMU(*this, std::move(Opts))))
return Err;
return ES.lookup({&JD}, MachOHeaderStartSymbol).takeError();
}
Error MachOPlatform::teardownJITDylib(JITDylib &JD) {
std::lock_guard<std::mutex> Lock(PlatformMutex);
auto I = JITDylibToHeaderAddr.find(&JD);
if (I != JITDylibToHeaderAddr.end()) {
assert(HeaderAddrToJITDylib.count(I->second) &&
"HeaderAddrToJITDylib missing entry");
HeaderAddrToJITDylib.erase(I->second);
JITDylibToHeaderAddr.erase(I);
}
JITDylibToPThreadKey.erase(&JD);
return Error::success();
}
Error MachOPlatform::notifyAdding(ResourceTracker &RT,
const MaterializationUnit &MU) {
auto &JD = RT.getJITDylib();
const auto &InitSym = MU.getInitializerSymbol();
if (!InitSym)
return Error::success();
RegisteredInitSymbols[&JD].add(InitSym,
SymbolLookupFlags::WeaklyReferencedSymbol);
LLVM_DEBUG({
dbgs() << "MachOPlatform: Registered init symbol " << *InitSym << " for MU "
<< MU.getName() << "\n";
});
return Error::success();
}
Error MachOPlatform::notifyRemoving(ResourceTracker &RT) {
llvm_unreachable("Not supported yet");
}
static void addAliases(ExecutionSession &ES, SymbolAliasMap &Aliases,
ArrayRef<std::pair<const char *, const char *>> AL) {
for (auto &KV : AL) {
auto AliasName = ES.intern(KV.first);
assert(!Aliases.count(AliasName) && "Duplicate symbol name in alias map");
Aliases[std::move(AliasName)] = {ES.intern(KV.second),
JITSymbolFlags::Exported};
}
}
SymbolAliasMap MachOPlatform::standardPlatformAliases(ExecutionSession &ES) {
SymbolAliasMap Aliases;
addAliases(ES, Aliases, requiredCXXAliases());
addAliases(ES, Aliases, standardRuntimeUtilityAliases());
return Aliases;
}
ArrayRef<std::pair<const char *, const char *>>
MachOPlatform::requiredCXXAliases() {
static const std::pair<const char *, const char *> RequiredCXXAliases[] = {
{"___cxa_atexit", "___orc_rt_macho_cxa_atexit"}};
return ArrayRef<std::pair<const char *, const char *>>(RequiredCXXAliases);
}
ArrayRef<std::pair<const char *, const char *>>
MachOPlatform::standardRuntimeUtilityAliases() {
static const std::pair<const char *, const char *>
StandardRuntimeUtilityAliases[] = {
{"___orc_rt_run_program", "___orc_rt_macho_run_program"},
{"___orc_rt_jit_dlerror", "___orc_rt_macho_jit_dlerror"},
{"___orc_rt_jit_dlopen", "___orc_rt_macho_jit_dlopen"},
{"___orc_rt_jit_dlclose", "___orc_rt_macho_jit_dlclose"},
{"___orc_rt_jit_dlsym", "___orc_rt_macho_jit_dlsym"},
{"___orc_rt_log_error", "___orc_rt_log_error_to_stderr"}};
return ArrayRef<std::pair<const char *, const char *>>(
StandardRuntimeUtilityAliases);
}
bool MachOPlatform::supportedTarget(const Triple &TT) {
switch (TT.getArch()) {
case Triple::aarch64:
case Triple::x86_64:
return true;
default:
return false;
}
}
jitlink::Edge::Kind MachOPlatform::getPointerEdgeKind(jitlink::LinkGraph &G) {
switch (G.getTargetTriple().getArch()) {
case Triple::aarch64:
return jitlink::aarch64::Pointer64;
case Triple::x86_64:
return jitlink::x86_64::Pointer64;
default:
llvm_unreachable("Unsupported architecture");
}
}
MachOPlatform::MachOExecutorSymbolFlags
MachOPlatform::flagsForSymbol(jitlink::Symbol &Sym) {
MachOPlatform::MachOExecutorSymbolFlags Flags{};
if (Sym.getLinkage() == jitlink::Linkage::Weak)
Flags |= MachOExecutorSymbolFlags::Weak;
if (Sym.isCallable())
Flags |= MachOExecutorSymbolFlags::Callable;
return Flags;
}
MachOPlatform::MachOPlatform(
ExecutionSession &ES, ObjectLinkingLayer &ObjLinkingLayer,
JITDylib &PlatformJD,
std::unique_ptr<DefinitionGenerator> OrcRuntimeGenerator,
HeaderOptions PlatformJDOpts, MachOHeaderMUBuilder BuildMachOHeaderMU,
Error &Err)
: ES(ES), PlatformJD(PlatformJD), ObjLinkingLayer(ObjLinkingLayer),
BuildMachOHeaderMU(std::move(BuildMachOHeaderMU)) {
ErrorAsOutParameter _(&Err);
ObjLinkingLayer.addPlugin(std::make_unique<MachOPlatformPlugin>(*this));
PlatformJD.addGenerator(std::move(OrcRuntimeGenerator));
BootstrapInfo BI;
Bootstrap = &BI;
// Bootstrap process -- here be phase-ordering dragons.
//
// The MachOPlatform class uses allocation actions to register metadata
// sections with the ORC runtime, however the runtime contains metadata
// registration functions that have their own metadata that they need to
// register (e.g. the frame-info registration functions have frame-info).
// We can't use an ordinary lookup to find these registration functions
// because their address is needed during the link of the containing graph
// itself (to build the allocation actions that will call the registration
// functions). Further complicating the situation (a) the graph containing
// the registration functions is allowed to depend on other graphs (e.g. the
// graph containing the ORC runtime RTTI support) so we need to handle an
// unknown set of dependencies during bootstrap, and (b) these graphs may
// be linked concurrently if the user has installed a concurrent dispatcher.
//
// We satisfy these constraints by implementing a bootstrap phase during which
// allocation actions generated by MachOPlatform are appended to a list of
// deferred allocation actions, rather than to the graphs themselves. At the
// end of the bootstrap process the deferred actions are attached to a final
// "complete-bootstrap" graph that causes them to be run.
//
// The bootstrap steps are as follows:
//
// 1. Request the graph containing the mach header. This graph is guaranteed
// not to have any metadata so the fact that the registration functions
// are not available yet is not a problem.
//
// 2. Look up the registration functions and discard the results. This will
// trigger linking of the graph containing these functions, and
// consequently any graphs that it depends on. We do not use the lookup
// result to find the addresses of the functions requested (as described
// above the lookup will return too late for that), instead we capture the
// addresses in a post-allocation pass injected by the platform runtime
// during bootstrap only.
//
// 3. During bootstrap the MachOPlatformPlugin keeps a count of the number of
// graphs being linked (potentially concurrently), and we block until all
// of these graphs have completed linking. This is to avoid a race on the
// deferred-actions vector: the lookup for the runtime registration
// functions may return while some functions (those that are being
// incidentally linked in, but aren't reachable via the runtime functions)
// are still being linked, and we need to capture any allocation actions
// for this incidental code before we proceed.
//
// 4. Once all active links are complete we transfer the deferred actions to
// a newly added CompleteBootstrap graph and then request a symbol from
// the CompleteBootstrap graph to trigger materialization. This will cause
// all deferred actions to be run, and once this lookup returns we can
// proceed.
//
// 5. Finally, we associate runtime support methods in MachOPlatform with
// the corresponding jit-dispatch tag variables in the ORC runtime to make
// the support methods callable. The bootstrap is now complete.
// Step (1) Add header materialization unit and request.
if ((Err = PlatformJD.define(
this->BuildMachOHeaderMU(*this, std::move(PlatformJDOpts)))))
return;
if ((Err = ES.lookup(&PlatformJD, MachOHeaderStartSymbol).takeError()))
return;
// Step (2) Request runtime registration functions to trigger
// materialization..
if ((Err = ES.lookup(makeJITDylibSearchOrder(&PlatformJD),
SymbolLookupSet(
{PlatformBootstrap.Name, PlatformShutdown.Name,
RegisterJITDylib.Name, DeregisterJITDylib.Name,
RegisterObjectSymbolTable.Name,
DeregisterObjectSymbolTable.Name,
RegisterObjectPlatformSections.Name,
DeregisterObjectPlatformSections.Name,
CreatePThreadKey.Name}))
.takeError()))
return;
// Step (3) Wait for any incidental linker work to complete.
{
std::unique_lock<std::mutex> Lock(BI.Mutex);
BI.CV.wait(Lock, [&]() { return BI.ActiveGraphs == 0; });
Bootstrap = nullptr;
}
// Step (4) Add complete-bootstrap materialization unit and request.
auto BootstrapCompleteSymbol = ES.intern("__orc_rt_macho_complete_bootstrap");
if ((Err = PlatformJD.define(
std::make_unique<MachOPlatformCompleteBootstrapMaterializationUnit>(
*this, PlatformJD.getName(), BootstrapCompleteSymbol,
std::move(BI.SymTab), std::move(BI.DeferredAAs),
BI.MachOHeaderAddr, PlatformBootstrap.Addr,
PlatformShutdown.Addr, RegisterJITDylib.Addr,
DeregisterJITDylib.Addr, RegisterObjectSymbolTable.Addr,
DeregisterObjectSymbolTable.Addr))))
return;
if ((Err = ES.lookup(makeJITDylibSearchOrder(
&PlatformJD, JITDylibLookupFlags::MatchAllSymbols),
std::move(BootstrapCompleteSymbol))
.takeError()))
return;
// (5) Associate runtime support functions.
if ((Err = associateRuntimeSupportFunctions()))
return;
}
Error MachOPlatform::associateRuntimeSupportFunctions() {
ExecutionSession::JITDispatchHandlerAssociationMap WFs;
using PushInitializersSPSSig =
SPSExpected<SPSMachOJITDylibDepInfoMap>(SPSExecutorAddr);
WFs[ES.intern("___orc_rt_macho_push_initializers_tag")] =
ES.wrapAsyncWithSPS<PushInitializersSPSSig>(
this, &MachOPlatform::rt_pushInitializers);
using PushSymbolsSPSSig =
SPSError(SPSExecutorAddr, SPSSequence<SPSTuple<SPSString, bool>>);
WFs[ES.intern("___orc_rt_macho_push_symbols_tag")] =
ES.wrapAsyncWithSPS<PushSymbolsSPSSig>(this,
&MachOPlatform::rt_pushSymbols);
return ES.registerJITDispatchHandlers(PlatformJD, std::move(WFs));
}
void MachOPlatform::pushInitializersLoop(
PushInitializersSendResultFn SendResult, JITDylibSP JD) {
DenseMap<JITDylib *, SymbolLookupSet> NewInitSymbols;
DenseMap<JITDylib *, SmallVector<JITDylib *>> JDDepMap;
SmallVector<JITDylib *, 16> Worklist({JD.get()});
ES.runSessionLocked([&]() {
while (!Worklist.empty()) {
// FIXME: Check for defunct dylibs.
auto DepJD = Worklist.back();
Worklist.pop_back();
// If we've already visited this JITDylib on this iteration then continue.
if (JDDepMap.count(DepJD))
continue;
// Add dep info.
auto &DM = JDDepMap[DepJD];
DepJD->withLinkOrderDo([&](const JITDylibSearchOrder &O) {
for (auto &KV : O) {
if (KV.first == DepJD)
continue;
DM.push_back(KV.first);
Worklist.push_back(KV.first);
}
});
// Add any registered init symbols.
auto RISItr = RegisteredInitSymbols.find(DepJD);
if (RISItr != RegisteredInitSymbols.end()) {
NewInitSymbols[DepJD] = std::move(RISItr->second);
RegisteredInitSymbols.erase(RISItr);
}
}
});
// If there are no further init symbols to look up then send the link order
// (as a list of header addresses) to the caller.
if (NewInitSymbols.empty()) {
// To make the list intelligible to the runtime we need to convert all
// JITDylib pointers to their header addresses. Only include JITDylibs
// that appear in the JITDylibToHeaderAddr map (i.e. those that have been
// through setupJITDylib) -- bare JITDylibs aren't managed by the platform.
DenseMap<JITDylib *, ExecutorAddr> HeaderAddrs;
HeaderAddrs.reserve(JDDepMap.size());
{
std::lock_guard<std::mutex> Lock(PlatformMutex);
for (auto &KV : JDDepMap) {
auto I = JITDylibToHeaderAddr.find(KV.first);
if (I != JITDylibToHeaderAddr.end())
HeaderAddrs[KV.first] = I->second;
}
}
// Build the dep info map to return.
MachOJITDylibDepInfoMap DIM;
DIM.reserve(JDDepMap.size());
for (auto &KV : JDDepMap) {
auto HI = HeaderAddrs.find(KV.first);
// Skip unmanaged JITDylibs.
if (HI == HeaderAddrs.end())
continue;
auto H = HI->second;
MachOJITDylibDepInfo DepInfo;
for (auto &Dep : KV.second) {
auto HJ = HeaderAddrs.find(Dep);
if (HJ != HeaderAddrs.end())
DepInfo.DepHeaders.push_back(HJ->second);
}
DIM.push_back(std::make_pair(H, std::move(DepInfo)));
}
SendResult(DIM);
return;
}
// Otherwise issue a lookup and re-run this phase when it completes.
lookupInitSymbolsAsync(
[this, SendResult = std::move(SendResult), JD](Error Err) mutable {
if (Err)
SendResult(std::move(Err));
else
pushInitializersLoop(std::move(SendResult), JD);
},
ES, std::move(NewInitSymbols));
}
void MachOPlatform::rt_pushInitializers(PushInitializersSendResultFn SendResult,
ExecutorAddr JDHeaderAddr) {
JITDylibSP JD;
{
std::lock_guard<std::mutex> Lock(PlatformMutex);
auto I = HeaderAddrToJITDylib.find(JDHeaderAddr);
if (I != HeaderAddrToJITDylib.end())
JD = I->second;
}
LLVM_DEBUG({
dbgs() << "MachOPlatform::rt_pushInitializers(" << JDHeaderAddr << ") ";
if (JD)
dbgs() << "pushing initializers for " << JD->getName() << "\n";
else
dbgs() << "No JITDylib for header address.\n";
});
if (!JD) {
SendResult(make_error<StringError>("No JITDylib with header addr " +
formatv("{0:x}", JDHeaderAddr),
inconvertibleErrorCode()));
return;
}
pushInitializersLoop(std::move(SendResult), JD);
}
void MachOPlatform::rt_pushSymbols(
PushSymbolsInSendResultFn SendResult, ExecutorAddr Handle,
const std::vector<std::pair<StringRef, bool>> &SymbolNames) {
JITDylib *JD = nullptr;
{
std::lock_guard<std::mutex> Lock(PlatformMutex);
auto I = HeaderAddrToJITDylib.find(Handle);
if (I != HeaderAddrToJITDylib.end())
JD = I->second;
}
LLVM_DEBUG({
dbgs() << "MachOPlatform::rt_pushSymbols(";
if (JD)
dbgs() << "\"" << JD->getName() << "\", [ ";
else
dbgs() << "<invalid handle " << Handle << ">, [ ";
for (auto &Name : SymbolNames)
dbgs() << "\"" << Name.first << "\" ";
dbgs() << "])\n";
});
if (!JD) {
SendResult(make_error<StringError>("No JITDylib associated with handle " +
formatv("{0:x}", Handle),
inconvertibleErrorCode()));
return;
}
SymbolLookupSet LS;
for (auto &[Name, Required] : SymbolNames)
LS.add(ES.intern(Name), Required
? SymbolLookupFlags::RequiredSymbol
: SymbolLookupFlags::WeaklyReferencedSymbol);
ES.lookup(
LookupKind::DLSym, {{JD, JITDylibLookupFlags::MatchExportedSymbolsOnly}},
std::move(LS), SymbolState::Ready,
[SendResult = std::move(SendResult)](Expected<SymbolMap> Result) mutable {
SendResult(Result.takeError());
},
NoDependenciesToRegister);
}
Expected<uint64_t> MachOPlatform::createPThreadKey() {
if (!CreatePThreadKey.Addr)
return make_error<StringError>(
"Attempting to create pthread key in target, but runtime support has "
"not been loaded yet",
inconvertibleErrorCode());
Expected<uint64_t> Result(0);
if (auto Err = ES.callSPSWrapper<SPSExpected<uint64_t>(void)>(
CreatePThreadKey.Addr, Result))
return std::move(Err);
return Result;
}
void MachOPlatform::MachOPlatformPlugin::modifyPassConfig(
MaterializationResponsibility &MR, jitlink::LinkGraph &LG,
jitlink::PassConfiguration &Config) {
using namespace jitlink;
bool InBootstrapPhase =
&MR.getTargetJITDylib() == &MP.PlatformJD && MP.Bootstrap;
// If we're in the bootstrap phase then increment the active graphs.
if (InBootstrapPhase) {
Config.PrePrunePasses.push_back(
[this](LinkGraph &G) { return bootstrapPipelineStart(G); });
Config.PostAllocationPasses.push_back([this](LinkGraph &G) {
return bootstrapPipelineRecordRuntimeFunctions(G);
});
}
// --- Handle Initializers ---
if (auto InitSymbol = MR.getInitializerSymbol()) {
// If the initializer symbol is the MachOHeader start symbol then just
// register it and then bail out -- the header materialization unit
// definitely doesn't need any other passes.
if (InitSymbol == MP.MachOHeaderStartSymbol && !InBootstrapPhase) {
Config.PostAllocationPasses.push_back([this, &MR](LinkGraph &G) {
return associateJITDylibHeaderSymbol(G, MR);
});
return;
}
// If the object contains an init symbol other than the header start symbol
// then add passes to preserve, process and register the init
// sections/symbols.
Config.PrePrunePasses.push_back([this, &MR](LinkGraph &G) {
if (auto Err = preserveImportantSections(G, MR))
return Err;
return processObjCImageInfo(G, MR);
});
Config.PostPrunePasses.push_back(
[this](LinkGraph &G) { return createObjCRuntimeObject(G); });
Config.PostAllocationPasses.push_back(
[this, &MR](LinkGraph &G) { return populateObjCRuntimeObject(G, MR); });
}
// Insert TLV lowering at the start of the PostPrunePasses, since we want
// it to run before GOT/PLT lowering.
Config.PostPrunePasses.insert(
Config.PostPrunePasses.begin(),
[this, &JD = MR.getTargetJITDylib()](LinkGraph &G) {
return fixTLVSectionsAndEdges(G, JD);
});
// Add symbol table prepare and register passes: These will add strings for
// all symbols to the c-strings section, and build a symbol table registration
// call.
auto JITSymTabInfo = std::make_shared<JITSymTabVector>();
Config.PostPrunePasses.push_back([this, JITSymTabInfo](LinkGraph &G) {
return prepareSymbolTableRegistration(G, *JITSymTabInfo);
});
Config.PostFixupPasses.push_back([this, &MR, JITSymTabInfo,
InBootstrapPhase](LinkGraph &G) {
return addSymbolTableRegistration(G, MR, *JITSymTabInfo, InBootstrapPhase);
});
// Add a pass to register the final addresses of any special sections in the
// object with the runtime.
Config.PostAllocationPasses.push_back(
[this, &JD = MR.getTargetJITDylib(), InBootstrapPhase](LinkGraph &G) {
return registerObjectPlatformSections(G, JD, InBootstrapPhase);
});
// If we're in the bootstrap phase then steal allocation actions and then
// decrement the active graphs.
if (InBootstrapPhase)
Config.PostFixupPasses.push_back(
[this](LinkGraph &G) { return bootstrapPipelineEnd(G); });
}
ObjectLinkingLayer::Plugin::SyntheticSymbolDependenciesMap
MachOPlatform::MachOPlatformPlugin::getSyntheticSymbolDependencies(
MaterializationResponsibility &MR) {
std::lock_guard<std::mutex> Lock(PluginMutex);
auto I = InitSymbolDeps.find(&MR);
if (I != InitSymbolDeps.end()) {
SyntheticSymbolDependenciesMap Result;
Result[MR.getInitializerSymbol()] = std::move(I->second);
InitSymbolDeps.erase(&MR);
return Result;
}
return SyntheticSymbolDependenciesMap();
}
Error MachOPlatform::MachOPlatformPlugin::bootstrapPipelineStart(
jitlink::LinkGraph &G) {
// Increment the active graphs count in BootstrapInfo.
std::lock_guard<std::mutex> Lock(MP.Bootstrap.load()->Mutex);
++MP.Bootstrap.load()->ActiveGraphs;
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::
bootstrapPipelineRecordRuntimeFunctions(jitlink::LinkGraph &G) {
// Record bootstrap function names.
std::pair<StringRef, ExecutorAddr *> RuntimeSymbols[] = {
{*MP.MachOHeaderStartSymbol, &MP.Bootstrap.load()->MachOHeaderAddr},
{*MP.PlatformBootstrap.Name, &MP.PlatformBootstrap.Addr},
{*MP.PlatformShutdown.Name, &MP.PlatformShutdown.Addr},
{*MP.RegisterJITDylib.Name, &MP.RegisterJITDylib.Addr},
{*MP.DeregisterJITDylib.Name, &MP.DeregisterJITDylib.Addr},
{*MP.RegisterObjectSymbolTable.Name, &MP.RegisterObjectSymbolTable.Addr},
{*MP.DeregisterObjectSymbolTable.Name,
&MP.DeregisterObjectSymbolTable.Addr},
{*MP.RegisterObjectPlatformSections.Name,
&MP.RegisterObjectPlatformSections.Addr},
{*MP.DeregisterObjectPlatformSections.Name,
&MP.DeregisterObjectPlatformSections.Addr},
{*MP.CreatePThreadKey.Name, &MP.CreatePThreadKey.Addr},
{*MP.RegisterObjCRuntimeObject.Name, &MP.RegisterObjCRuntimeObject.Addr},
{*MP.DeregisterObjCRuntimeObject.Name,
&MP.DeregisterObjCRuntimeObject.Addr}};
bool RegisterMachOHeader = false;
for (auto *Sym : G.defined_symbols()) {
for (auto &RTSym : RuntimeSymbols) {
if (Sym->hasName() && Sym->getName() == RTSym.first) {
if (*RTSym.second)
return make_error<StringError>(
"Duplicate " + RTSym.first +
" detected during MachOPlatform bootstrap",
inconvertibleErrorCode());
if (Sym->getName() == *MP.MachOHeaderStartSymbol)
RegisterMachOHeader = true;
*RTSym.second = Sym->getAddress();
}
}
}
if (RegisterMachOHeader) {
// If this graph defines the macho header symbol then create the internal
// mapping between it and PlatformJD.
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
MP.JITDylibToHeaderAddr[&MP.PlatformJD] =
MP.Bootstrap.load()->MachOHeaderAddr;
MP.HeaderAddrToJITDylib[MP.Bootstrap.load()->MachOHeaderAddr] =
&MP.PlatformJD;
}
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::bootstrapPipelineEnd(
jitlink::LinkGraph &G) {
std::lock_guard<std::mutex> Lock(MP.Bootstrap.load()->Mutex);
assert(MP.Bootstrap && "DeferredAAs reset before bootstrap completed");
--MP.Bootstrap.load()->ActiveGraphs;
// Notify Bootstrap->CV while holding the mutex because the mutex is
// also keeping Bootstrap->CV alive.
if (MP.Bootstrap.load()->ActiveGraphs == 0)
MP.Bootstrap.load()->CV.notify_all();
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::associateJITDylibHeaderSymbol(
jitlink::LinkGraph &G, MaterializationResponsibility &MR) {
auto I = llvm::find_if(G.defined_symbols(), [this](jitlink::Symbol *Sym) {
return Sym->getName() == *MP.MachOHeaderStartSymbol;
});
assert(I != G.defined_symbols().end() && "Missing MachO header start symbol");
auto &JD = MR.getTargetJITDylib();
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
auto HeaderAddr = (*I)->getAddress();
MP.JITDylibToHeaderAddr[&JD] = HeaderAddr;
MP.HeaderAddrToJITDylib[HeaderAddr] = &JD;
// We can unconditionally add these actions to the Graph because this pass
// isn't used during bootstrap.
G.allocActions().push_back(
{cantFail(
WrapperFunctionCall::Create<SPSArgList<SPSString, SPSExecutorAddr>>(
MP.RegisterJITDylib.Addr, JD.getName(), HeaderAddr)),
cantFail(WrapperFunctionCall::Create<SPSArgList<SPSExecutorAddr>>(
MP.DeregisterJITDylib.Addr, HeaderAddr))});
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::preserveImportantSections(
jitlink::LinkGraph &G, MaterializationResponsibility &MR) {
// __objc_imageinfo is "important": we want to preserve it and record its
// address in the first graph that it appears in, then verify and discard it
// in all subsequent graphs. In this pass we preserve unconditionally -- we'll
// manually throw it away in the processObjCImageInfo pass.
if (auto *ObjCImageInfoSec =
G.findSectionByName(MachOObjCImageInfoSectionName)) {
if (ObjCImageInfoSec->blocks_size() != 1)
return make_error<StringError>(
"In " + G.getName() +
"__DATA,__objc_imageinfo contains multiple blocks",
inconvertibleErrorCode());
G.addAnonymousSymbol(**ObjCImageInfoSec->blocks().begin(), 0, 0, false,
true);
for (auto *B : ObjCImageInfoSec->blocks())
if (!B->edges_empty())
return make_error<StringError>("In " + G.getName() + ", " +
MachOObjCImageInfoSectionName +
" contains references to symbols",
inconvertibleErrorCode());
}
// Init sections are important: We need to preserve them and so that their
// addresses can be captured and reported to the ORC runtime in
// registerObjectPlatformSections.
JITLinkSymbolSet InitSectionSymbols;
for (auto &InitSectionName : MachOInitSectionNames) {
// Skip ObjCImageInfo -- this shouldn't have any dependencies, and we may
// remove it later.
if (InitSectionName == MachOObjCImageInfoSectionName)
continue;
// Skip non-init sections.
auto *InitSection = G.findSectionByName(InitSectionName);
if (!InitSection)
continue;
// Make a pass over live symbols in the section: those blocks are already
// preserved.
DenseSet<jitlink::Block *> AlreadyLiveBlocks;
for (auto &Sym : InitSection->symbols()) {
auto &B = Sym->getBlock();
if (Sym->isLive() && Sym->getOffset() == 0 &&
Sym->getSize() == B.getSize() && !AlreadyLiveBlocks.count(&B)) {
InitSectionSymbols.insert(Sym);
AlreadyLiveBlocks.insert(&B);
}
}
// Add anonymous symbols to preserve any not-already-preserved blocks.
for (auto *B : InitSection->blocks())
if (!AlreadyLiveBlocks.count(B))
InitSectionSymbols.insert(
&G.addAnonymousSymbol(*B, 0, B->getSize(), false, true));
}
if (!InitSectionSymbols.empty()) {
std::lock_guard<std::mutex> Lock(PluginMutex);
InitSymbolDeps[&MR] = std::move(InitSectionSymbols);
}
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::processObjCImageInfo(
jitlink::LinkGraph &G, MaterializationResponsibility &MR) {
// If there's an ObjC imagine info then either
// (1) It's the first __objc_imageinfo we've seen in this JITDylib. In
// this case we name and record it.
// OR
// (2) We already have a recorded __objc_imageinfo for this JITDylib,
// in which case we just verify it.
auto *ObjCImageInfo = G.findSectionByName(MachOObjCImageInfoSectionName);
if (!ObjCImageInfo)
return Error::success();
auto ObjCImageInfoBlocks = ObjCImageInfo->blocks();
// Check that the section is not empty if present.
if (ObjCImageInfoBlocks.empty())
return make_error<StringError>("Empty " + MachOObjCImageInfoSectionName +
" section in " + G.getName(),
inconvertibleErrorCode());
// Check that there's only one block in the section.
if (std::next(ObjCImageInfoBlocks.begin()) != ObjCImageInfoBlocks.end())
return make_error<StringError>("Multiple blocks in " +
MachOObjCImageInfoSectionName +
" section in " + G.getName(),
inconvertibleErrorCode());
// Check that the __objc_imageinfo section is unreferenced.
// FIXME: We could optimize this check if Symbols had a ref-count.
for (auto &Sec : G.sections()) {
if (&Sec != ObjCImageInfo)
for (auto *B : Sec.blocks())
for (auto &E : B->edges())
if (E.getTarget().isDefined() &&
&E.getTarget().getBlock().getSection() == ObjCImageInfo)
return make_error<StringError>(MachOObjCImageInfoSectionName +
" is referenced within file " +
G.getName(),
inconvertibleErrorCode());
}
auto &ObjCImageInfoBlock = **ObjCImageInfoBlocks.begin();
auto *ObjCImageInfoData = ObjCImageInfoBlock.getContent().data();
auto Version = support::endian::read32(ObjCImageInfoData, G.getEndianness());
auto Flags =
support::endian::read32(ObjCImageInfoData + 4, G.getEndianness());
// Lock the mutex while we verify / update the ObjCImageInfos map.
std::lock_guard<std::mutex> Lock(PluginMutex);
auto ObjCImageInfoItr = ObjCImageInfos.find(&MR.getTargetJITDylib());
if (ObjCImageInfoItr != ObjCImageInfos.end()) {
// We've already registered an __objc_imageinfo section. Verify the
// content of this new section matches, then delete it.
if (ObjCImageInfoItr->second.Version != Version)
return make_error<StringError>(
"ObjC version in " + G.getName() +
" does not match first registered version",
inconvertibleErrorCode());
if (ObjCImageInfoItr->second.Flags != Flags)
if (Error E = mergeImageInfoFlags(G, MR, ObjCImageInfoItr->second, Flags))
return E;
// __objc_imageinfo is valid. Delete the block.
for (auto *S : ObjCImageInfo->symbols())
G.removeDefinedSymbol(*S);
G.removeBlock(ObjCImageInfoBlock);
} else {
LLVM_DEBUG({
dbgs() << "MachOPlatform: Registered __objc_imageinfo for "
<< MR.getTargetJITDylib().getName() << " in " << G.getName()
<< "; flags = " << formatv("{0:x4}", Flags) << "\n";
});
// We haven't registered an __objc_imageinfo section yet. Register and
// move on. The section should already be marked no-dead-strip.
G.addDefinedSymbol(ObjCImageInfoBlock, 0, ObjCImageInfoSymbolName,
ObjCImageInfoBlock.getSize(), jitlink::Linkage::Strong,
jitlink::Scope::Hidden, false, true);
if (auto Err = MR.defineMaterializing(
{{MR.getExecutionSession().intern(ObjCImageInfoSymbolName),
JITSymbolFlags()}}))
return Err;
ObjCImageInfos[&MR.getTargetJITDylib()] = {Version, Flags, false};
}
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::mergeImageInfoFlags(
jitlink::LinkGraph &G, MaterializationResponsibility &MR,
ObjCImageInfo &Info, uint32_t NewFlags) {
if (Info.Flags == NewFlags)
return Error::success();
ObjCImageInfoFlags Old(Info.Flags);
ObjCImageInfoFlags New(NewFlags);
// Check for incompatible flags.
if (Old.SwiftABIVersion && New.SwiftABIVersion &&
Old.SwiftABIVersion != New.SwiftABIVersion)
return make_error<StringError>("Swift ABI version in " + G.getName() +
" does not match first registered flags",
inconvertibleErrorCode());
if (Old.HasCategoryClassProperties != New.HasCategoryClassProperties)
return make_error<StringError>("ObjC category class property support in " +
G.getName() +
" does not match first registered flags",
inconvertibleErrorCode());
if (Old.HasSignedObjCClassROs != New.HasSignedObjCClassROs)
return make_error<StringError>("ObjC class_ro_t pointer signing in " +
G.getName() +
" does not match first registered flags",
inconvertibleErrorCode());
// If we cannot change the flags, ignore any remaining differences. Adding
// Swift or changing its version are unlikely to cause problems in practice.
if (Info.Finalized)
return Error::success();
// Use the minimum Swift version.
if (Old.SwiftVersion && New.SwiftVersion)
New.SwiftVersion = std::min(Old.SwiftVersion, New.SwiftVersion);
else if (Old.SwiftVersion)
New.SwiftVersion = Old.SwiftVersion;
// Add a Swift ABI version if it was pure objc before.
if (!New.SwiftABIVersion)
New.SwiftABIVersion = Old.SwiftABIVersion;
LLVM_DEBUG({
dbgs() << "MachOPlatform: Merging __objc_imageinfo flags for "
<< MR.getTargetJITDylib().getName() << " (was "
<< formatv("{0:x4}", Old.rawFlags()) << ")"
<< " with " << G.getName() << " (" << formatv("{0:x4}", NewFlags)
<< ")"
<< " -> " << formatv("{0:x4}", New.rawFlags()) << "\n";
});
Info.Flags = New.rawFlags();
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::fixTLVSectionsAndEdges(
jitlink::LinkGraph &G, JITDylib &JD) {
// Rename external references to __tlv_bootstrap to ___orc_rt_tlv_get_addr.
for (auto *Sym : G.external_symbols())
if (Sym->getName() == "__tlv_bootstrap") {
Sym->setName("___orc_rt_macho_tlv_get_addr");
break;
}
// Store key in __thread_vars struct fields.
if (auto *ThreadDataSec = G.findSectionByName(MachOThreadVarsSectionName)) {
std::optional<uint64_t> Key;
{
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
auto I = MP.JITDylibToPThreadKey.find(&JD);
if (I != MP.JITDylibToPThreadKey.end())
Key = I->second;
}
if (!Key) {
if (auto KeyOrErr = MP.createPThreadKey())
Key = *KeyOrErr;
else
return KeyOrErr.takeError();
}
uint64_t PlatformKeyBits =
support::endian::byte_swap(*Key, G.getEndianness());
for (auto *B : ThreadDataSec->blocks()) {
if (B->getSize() != 3 * G.getPointerSize())
return make_error<StringError>("__thread_vars block at " +
formatv("{0:x}", B->getAddress()) +
" has unexpected size",
inconvertibleErrorCode());
auto NewBlockContent = G.allocateBuffer(B->getSize());
llvm::copy(B->getContent(), NewBlockContent.data());
memcpy(NewBlockContent.data() + G.getPointerSize(), &PlatformKeyBits,
G.getPointerSize());
B->setContent(NewBlockContent);
}
}
// Transform any TLV edges into GOT edges.
for (auto *B : G.blocks())
for (auto &E : B->edges())
if (E.getKind() ==
jitlink::x86_64::RequestTLVPAndTransformToPCRel32TLVPLoadREXRelaxable)
E.setKind(jitlink::x86_64::
RequestGOTAndTransformToPCRel32GOTLoadREXRelaxable);
return Error::success();
}
std::optional<MachOPlatform::MachOPlatformPlugin::UnwindSections>
MachOPlatform::MachOPlatformPlugin::findUnwindSectionInfo(
jitlink::LinkGraph &G) {
using namespace jitlink;
UnwindSections US;
// ScanSection records a section range and adds any executable blocks that
// that section points to to the CodeBlocks vector.
SmallVector<Block *> CodeBlocks;
auto ScanUnwindInfoSection = [&](Section &Sec, ExecutorAddrRange &SecRange) {
if (Sec.blocks().empty())
return;
SecRange = (*Sec.blocks().begin())->getRange();
for (auto *B : Sec.blocks()) {
auto R = B->getRange();
SecRange.Start = std::min(SecRange.Start, R.Start);
SecRange.End = std::max(SecRange.End, R.End);
for (auto &E : B->edges()) {
if (!E.getTarget().isDefined())
continue;
auto &TargetBlock = E.getTarget().getBlock();
auto &TargetSection = TargetBlock.getSection();
if ((TargetSection.getMemProt() & MemProt::Exec) == MemProt::Exec)
CodeBlocks.push_back(&TargetBlock);
}
}
};
if (Section *EHFrameSec = G.findSectionByName(MachOEHFrameSectionName))
ScanUnwindInfoSection(*EHFrameSec, US.DwarfSection);
if (Section *CUInfoSec =
G.findSectionByName(MachOCompactUnwindInfoSectionName))
ScanUnwindInfoSection(*CUInfoSec, US.CompactUnwindSection);
// If we didn't find any pointed-to code-blocks then there's no need to
// register any info.
if (CodeBlocks.empty())
return std::nullopt;
// We have info to register. Sort the code blocks into address order and
// build a list of contiguous address ranges covering them all.
llvm::sort(CodeBlocks, [](const Block *LHS, const Block *RHS) {
return LHS->getAddress() < RHS->getAddress();
});
for (auto *B : CodeBlocks) {
if (US.CodeRanges.empty() || US.CodeRanges.back().End != B->getAddress())
US.CodeRanges.push_back(B->getRange());
else
US.CodeRanges.back().End = B->getRange().End;
}
LLVM_DEBUG({
dbgs() << "MachOPlatform identified unwind info in " << G.getName() << ":\n"
<< " DWARF: ";
if (US.DwarfSection.Start)
dbgs() << US.DwarfSection << "\n";
else
dbgs() << "none\n";
dbgs() << " Compact-unwind: ";
if (US.CompactUnwindSection.Start)
dbgs() << US.CompactUnwindSection << "\n";
else
dbgs() << "none\n"
<< "for code ranges:\n";
for (auto &CR : US.CodeRanges)
dbgs() << " " << CR << "\n";
if (US.CodeRanges.size() >= G.sections_size())
dbgs() << "WARNING: High number of discontiguous code ranges! "
"Padding may be interfering with coalescing.\n";
});
return US;
}
Error MachOPlatform::MachOPlatformPlugin::registerObjectPlatformSections(
jitlink::LinkGraph &G, JITDylib &JD, bool InBootstrapPhase) {
// Get a pointer to the thread data section if there is one. It will be used
// below.
jitlink::Section *ThreadDataSection =
G.findSectionByName(MachOThreadDataSectionName);
// Handle thread BSS section if there is one.
if (auto *ThreadBSSSection = G.findSectionByName(MachOThreadBSSSectionName)) {
// If there's already a thread data section in this graph then merge the
// thread BSS section content into it, otherwise just treat the thread
// BSS section as the thread data section.
if (ThreadDataSection)
G.mergeSections(*ThreadDataSection, *ThreadBSSSection);
else
ThreadDataSection = ThreadBSSSection;
}
SmallVector<std::pair<StringRef, ExecutorAddrRange>, 8> MachOPlatformSecs;
// Collect data sections to register.
StringRef DataSections[] = {MachODataDataSectionName,
MachODataCommonSectionName,
MachOEHFrameSectionName};
for (auto &SecName : DataSections) {
if (auto *Sec = G.findSectionByName(SecName)) {
jitlink::SectionRange R(*Sec);
if (!R.empty())
MachOPlatformSecs.push_back({SecName, R.getRange()});
}
}
// Having merged thread BSS (if present) and thread data (if present),
// record the resulting section range.
if (ThreadDataSection) {
jitlink::SectionRange R(*ThreadDataSection);
if (!R.empty())
MachOPlatformSecs.push_back({MachOThreadDataSectionName, R.getRange()});
}
// If any platform sections were found then add an allocation action to call
// the registration function.
StringRef PlatformSections[] = {MachOModInitFuncSectionName,
ObjCRuntimeObjectSectionName};
for (auto &SecName : PlatformSections) {
auto *Sec = G.findSectionByName(SecName);
if (!Sec)
continue;
jitlink::SectionRange R(*Sec);
if (R.empty())
continue;
MachOPlatformSecs.push_back({SecName, R.getRange()});
}
std::optional<std::tuple<SmallVector<ExecutorAddrRange>, ExecutorAddrRange,
ExecutorAddrRange>>
UnwindInfo;
if (auto UI = findUnwindSectionInfo(G))
UnwindInfo = std::make_tuple(std::move(UI->CodeRanges), UI->DwarfSection,
UI->CompactUnwindSection);
if (!MachOPlatformSecs.empty() || UnwindInfo) {
// Dump the scraped inits.
LLVM_DEBUG({
dbgs() << "MachOPlatform: Scraped " << G.getName() << " init sections:\n";
for (auto &KV : MachOPlatformSecs)
dbgs() << " " << KV.first << ": " << KV.second << "\n";
});
using SPSRegisterObjectPlatformSectionsArgs = SPSArgList<
SPSExecutorAddr,
SPSOptional<SPSTuple<SPSSequence<SPSExecutorAddrRange>,
SPSExecutorAddrRange, SPSExecutorAddrRange>>,
SPSSequence<SPSTuple<SPSString, SPSExecutorAddrRange>>>;
shared::AllocActions &allocActions = LLVM_LIKELY(!InBootstrapPhase)
? G.allocActions()
: MP.Bootstrap.load()->DeferredAAs;
ExecutorAddr HeaderAddr;
{
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
auto I = MP.JITDylibToHeaderAddr.find(&JD);
assert(I != MP.JITDylibToHeaderAddr.end() &&
"No header registered for JD");
assert(I->second && "Null header registered for JD");
HeaderAddr = I->second;
}
allocActions.push_back(
{cantFail(
WrapperFunctionCall::Create<SPSRegisterObjectPlatformSectionsArgs>(
MP.RegisterObjectPlatformSections.Addr, HeaderAddr, UnwindInfo,
MachOPlatformSecs)),
cantFail(
WrapperFunctionCall::Create<SPSRegisterObjectPlatformSectionsArgs>(
MP.DeregisterObjectPlatformSections.Addr, HeaderAddr,
UnwindInfo, MachOPlatformSecs))});
}
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::createObjCRuntimeObject(
jitlink::LinkGraph &G) {
bool NeedTextSegment = false;
size_t NumRuntimeSections = 0;
for (auto ObjCRuntimeSectionName : ObjCRuntimeObjectSectionsData)
if (G.findSectionByName(ObjCRuntimeSectionName))
++NumRuntimeSections;
for (auto ObjCRuntimeSectionName : ObjCRuntimeObjectSectionsText) {
if (G.findSectionByName(ObjCRuntimeSectionName)) {
++NumRuntimeSections;
NeedTextSegment = true;
}
}
// Early out for no runtime sections.
if (NumRuntimeSections == 0)
return Error::success();
// If there were any runtime sections then we need to add an __objc_imageinfo
// section.
++NumRuntimeSections;
size_t MachOSize = sizeof(MachO::mach_header_64) +
(NeedTextSegment + 1) * sizeof(MachO::segment_command_64) +
NumRuntimeSections * sizeof(MachO::section_64);
auto &Sec = G.createSection(ObjCRuntimeObjectSectionName,
MemProt::Read | MemProt::Write);
G.createMutableContentBlock(Sec, MachOSize, ExecutorAddr(), 16, 0, true);
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::populateObjCRuntimeObject(
jitlink::LinkGraph &G, MaterializationResponsibility &MR) {
auto *ObjCRuntimeObjectSec =
G.findSectionByName(ObjCRuntimeObjectSectionName);
if (!ObjCRuntimeObjectSec)
return Error::success();
switch (G.getTargetTriple().getArch()) {
case Triple::aarch64:
case Triple::x86_64:
// Supported.
break;
default:
return make_error<StringError>("Unrecognized MachO arch in triple " +
G.getTargetTriple().str(),
inconvertibleErrorCode());
}
auto &SecBlock = **ObjCRuntimeObjectSec->blocks().begin();
struct SecDesc {
MachO::section_64 Sec;
unique_function<void(size_t RecordOffset)> AddFixups;
};
std::vector<SecDesc> TextSections, DataSections;
auto AddSection = [&](SecDesc &SD, jitlink::Section &GraphSec) {
jitlink::SectionRange SR(GraphSec);
StringRef FQName = GraphSec.getName();
memset(&SD.Sec, 0, sizeof(MachO::section_64));
memcpy(SD.Sec.sectname, FQName.drop_front(7).data(), FQName.size() - 7);
memcpy(SD.Sec.segname, FQName.data(), 6);
SD.Sec.addr = SR.getStart() - SecBlock.getAddress();
SD.Sec.size = SR.getSize();
SD.Sec.flags = MachO::S_REGULAR;
};
// Add the __objc_imageinfo section.
{
DataSections.push_back({});
auto &SD = DataSections.back();
memset(&SD.Sec, 0, sizeof(SD.Sec));
memcpy(SD.Sec.sectname, "__objc_imageinfo", 16);
strcpy(SD.Sec.segname, "__DATA");
SD.Sec.size = 8;
SD.AddFixups = [&](size_t RecordOffset) {
auto PointerEdge = getPointerEdgeKind(G);
// Look for an existing __objc_imageinfo symbol.
jitlink::Symbol *ObjCImageInfoSym = nullptr;
for (auto *Sym : G.external_symbols())
if (Sym->getName() == ObjCImageInfoSymbolName) {
ObjCImageInfoSym = Sym;
break;
}
if (!ObjCImageInfoSym)
for (auto *Sym : G.absolute_symbols())
if (Sym->getName() == ObjCImageInfoSymbolName) {
ObjCImageInfoSym = Sym;
break;
}
if (!ObjCImageInfoSym)
for (auto *Sym : G.defined_symbols())
if (Sym->hasName() && Sym->getName() == ObjCImageInfoSymbolName) {
ObjCImageInfoSym = Sym;
std::optional<uint32_t> Flags;
{
std::lock_guard<std::mutex> Lock(PluginMutex);
auto It = ObjCImageInfos.find(&MR.getTargetJITDylib());
if (It != ObjCImageInfos.end()) {
It->second.Finalized = true;
Flags = It->second.Flags;
}
}
if (Flags) {
// We own the definition of __objc_image_info; write the final
// merged flags value.
auto Content = Sym->getBlock().getMutableContent(G);
assert(Content.size() == 8 &&
"__objc_image_info size should have been verified already");
support::endian::write32(&Content[4], *Flags, G.getEndianness());
}
break;
}
if (!ObjCImageInfoSym)
ObjCImageInfoSym =
&G.addExternalSymbol(ObjCImageInfoSymbolName, 8, false);
SecBlock.addEdge(PointerEdge,
RecordOffset + ((char *)&SD.Sec.addr - (char *)&SD.Sec),
*ObjCImageInfoSym, -SecBlock.getAddress().getValue());
};
}
for (auto ObjCRuntimeSectionName : ObjCRuntimeObjectSectionsData) {
if (auto *GraphSec = G.findSectionByName(ObjCRuntimeSectionName)) {
DataSections.push_back({});
AddSection(DataSections.back(), *GraphSec);
}
}
for (auto ObjCRuntimeSectionName : ObjCRuntimeObjectSectionsText) {
if (auto *GraphSec = G.findSectionByName(ObjCRuntimeSectionName)) {
TextSections.push_back({});
AddSection(TextSections.back(), *GraphSec);
}
}
assert(ObjCRuntimeObjectSec->blocks_size() == 1 &&
"Unexpected number of blocks in runtime sections object");
// Build the header struct up-front. This also gives us a chance to check
// that the triple is supported, which we'll assume below.
MachO::mach_header_64 Hdr;
Hdr.magic = MachO::MH_MAGIC_64;
switch (G.getTargetTriple().getArch()) {
case Triple::aarch64:
Hdr.cputype = MachO::CPU_TYPE_ARM64;
Hdr.cpusubtype = MachO::CPU_SUBTYPE_ARM64_ALL;
break;
case Triple::x86_64:
Hdr.cputype = MachO::CPU_TYPE_X86_64;
Hdr.cpusubtype = MachO::CPU_SUBTYPE_X86_64_ALL;
break;
default:
llvm_unreachable("Unsupported architecture");
}
Hdr.filetype = MachO::MH_DYLIB;
Hdr.ncmds = 1 + !TextSections.empty();
Hdr.sizeofcmds =
Hdr.ncmds * sizeof(MachO::segment_command_64) +
(TextSections.size() + DataSections.size()) * sizeof(MachO::section_64);
Hdr.flags = 0;
Hdr.reserved = 0;
auto SecContent = SecBlock.getAlreadyMutableContent();
char *P = SecContent.data();
auto WriteMachOStruct = [&](auto S) {
if (G.getEndianness() != llvm::endianness::native)
MachO::swapStruct(S);
memcpy(P, &S, sizeof(S));
P += sizeof(S);
};
auto WriteSegment = [&](StringRef Name, std::vector<SecDesc> &Secs) {
MachO::segment_command_64 SegLC;
memset(&SegLC, 0, sizeof(SegLC));
memcpy(SegLC.segname, Name.data(), Name.size());
SegLC.cmd = MachO::LC_SEGMENT_64;
SegLC.cmdsize = sizeof(MachO::segment_command_64) +
Secs.size() * sizeof(MachO::section_64);
SegLC.nsects = Secs.size();
WriteMachOStruct(SegLC);
for (auto &SD : Secs) {
if (SD.AddFixups)
SD.AddFixups(P - SecContent.data());
WriteMachOStruct(SD.Sec);
}
};
WriteMachOStruct(Hdr);
if (!TextSections.empty())
WriteSegment("__TEXT", TextSections);
if (!DataSections.empty())
WriteSegment("__DATA", DataSections);
assert(P == SecContent.end() && "Underflow writing ObjC runtime object");
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::prepareSymbolTableRegistration(
jitlink::LinkGraph &G, JITSymTabVector &JITSymTabInfo) {
auto *CStringSec = G.findSectionByName(MachOCStringSectionName);
if (!CStringSec)
CStringSec = &G.createSection(MachOCStringSectionName,
MemProt::Read | MemProt::Exec);
// Make a map of existing strings so that we can re-use them:
DenseMap<StringRef, jitlink::Symbol *> ExistingStrings;
for (auto *Sym : CStringSec->symbols()) {
// The LinkGraph builder should have created single strings blocks, and all
// plugins should have maintained this invariant.
auto Content = Sym->getBlock().getContent();
ExistingStrings.insert(
std::make_pair(StringRef(Content.data(), Content.size()), Sym));
}
// Add all symbol names to the string section, and record the symbols for
// those names.
{
SmallVector<jitlink::Symbol *> SymsToProcess;
for (auto *Sym : G.defined_symbols())
SymsToProcess.push_back(Sym);
for (auto *Sym : G.absolute_symbols())
SymsToProcess.push_back(Sym);
for (auto *Sym : SymsToProcess) {
if (!Sym->hasName())
continue;
auto I = ExistingStrings.find(Sym->getName());
if (I == ExistingStrings.end()) {
auto &NameBlock = G.createMutableContentBlock(
*CStringSec, G.allocateCString(Sym->getName()), orc::ExecutorAddr(),
1, 0);
auto &SymbolNameSym = G.addAnonymousSymbol(
NameBlock, 0, NameBlock.getSize(), false, true);
JITSymTabInfo.push_back({Sym, &SymbolNameSym});
} else
JITSymTabInfo.push_back({Sym, I->second});
}
}
return Error::success();
}
Error MachOPlatform::MachOPlatformPlugin::addSymbolTableRegistration(
jitlink::LinkGraph &G, MaterializationResponsibility &MR,
JITSymTabVector &JITSymTabInfo, bool InBootstrapPhase) {
ExecutorAddr HeaderAddr;
{
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
auto I = MP.JITDylibToHeaderAddr.find(&MR.getTargetJITDylib());
assert(I != MP.JITDylibToHeaderAddr.end() && "No header registered for JD");
assert(I->second && "Null header registered for JD");
HeaderAddr = I->second;
}
SymbolTableVector LocalSymTab;
auto &SymTab = LLVM_LIKELY(!InBootstrapPhase) ? LocalSymTab
: MP.Bootstrap.load()->SymTab;
for (auto &[OriginalSymbol, NameSym] : JITSymTabInfo)
SymTab.push_back({NameSym->getAddress(), OriginalSymbol->getAddress(),
flagsForSymbol(*OriginalSymbol)});
// Bail out if we're in the bootstrap phase -- registration of thees symbols
// will be attached to the bootstrap graph.
if (LLVM_UNLIKELY(InBootstrapPhase))
return Error::success();
shared::AllocActions &allocActions = LLVM_LIKELY(!InBootstrapPhase)
? G.allocActions()
: MP.Bootstrap.load()->DeferredAAs;
allocActions.push_back(
{cantFail(WrapperFunctionCall::Create<SPSRegisterSymbolsArgs>(
MP.RegisterObjectSymbolTable.Addr, HeaderAddr, SymTab)),
cantFail(WrapperFunctionCall::Create<SPSRegisterSymbolsArgs>(
MP.DeregisterObjectSymbolTable.Addr, HeaderAddr, SymTab))});
return Error::success();
}
template <typename MachOTraits>
jitlink::Block &createHeaderBlock(MachOPlatform &MOP,
const MachOPlatform::HeaderOptions &Opts,
JITDylib &JD, jitlink::LinkGraph &G,
jitlink::Section &HeaderSection) {
auto HdrInfo =
getMachOHeaderInfoFromTriple(MOP.getExecutionSession().getTargetTriple());
MachOBuilder<MachOTraits> B(HdrInfo.PageSize);
B.Header.filetype = MachO::MH_DYLIB;
B.Header.cputype = HdrInfo.CPUType;
B.Header.cpusubtype = HdrInfo.CPUSubType;
if (Opts.IDDylib)
B.template addLoadCommand<MachO::LC_ID_DYLIB>(
Opts.IDDylib->Name, Opts.IDDylib->Timestamp,
Opts.IDDylib->CurrentVersion, Opts.IDDylib->CompatibilityVersion);
else
B.template addLoadCommand<MachO::LC_ID_DYLIB>(JD.getName(), 0, 0, 0);
for (auto &D : Opts.LoadDylibs)
B.template addLoadCommand<MachO::LC_LOAD_DYLIB>(
D.Name, D.Timestamp, D.CurrentVersion, D.CompatibilityVersion);
for (auto &P : Opts.RPaths)
B.template addLoadCommand<MachO::LC_RPATH>(P);
auto HeaderContent = G.allocateBuffer(B.layout());
B.write(HeaderContent);
return G.createContentBlock(HeaderSection, HeaderContent, ExecutorAddr(), 8,
0);
}
SimpleMachOHeaderMU::SimpleMachOHeaderMU(MachOPlatform &MOP,
SymbolStringPtr HeaderStartSymbol,
MachOPlatform::HeaderOptions Opts)
: MaterializationUnit(
createHeaderInterface(MOP, std::move(HeaderStartSymbol))),
MOP(MOP), Opts(std::move(Opts)) {}
void SimpleMachOHeaderMU::materialize(
std::unique_ptr<MaterializationResponsibility> R) {
auto G = createPlatformGraph(MOP, "<MachOHeaderMU>");
addMachOHeader(R->getTargetJITDylib(), *G, R->getInitializerSymbol());
MOP.getObjectLinkingLayer().emit(std::move(R), std::move(G));
}
void SimpleMachOHeaderMU::discard(const JITDylib &JD,
const SymbolStringPtr &Sym) {}
void SimpleMachOHeaderMU::addMachOHeader(
JITDylib &JD, jitlink::LinkGraph &G,
const SymbolStringPtr &InitializerSymbol) {
auto &HeaderSection = G.createSection("__header", MemProt::Read);
auto &HeaderBlock = createHeaderBlock(JD, G, HeaderSection);
// Init symbol is header-start symbol.
G.addDefinedSymbol(HeaderBlock, 0, *InitializerSymbol, HeaderBlock.getSize(),
jitlink::Linkage::Strong, jitlink::Scope::Default, false,
true);
for (auto &HS : AdditionalHeaderSymbols)
G.addDefinedSymbol(HeaderBlock, HS.Offset, HS.Name, HeaderBlock.getSize(),
jitlink::Linkage::Strong, jitlink::Scope::Default, false,
true);
}
jitlink::Block &
SimpleMachOHeaderMU::createHeaderBlock(JITDylib &JD, jitlink::LinkGraph &G,
jitlink::Section &HeaderSection) {
switch (MOP.getExecutionSession().getTargetTriple().getArch()) {
case Triple::aarch64:
case Triple::x86_64:
return ::createHeaderBlock<MachO64LE>(MOP, Opts, JD, G, HeaderSection);
default:
llvm_unreachable("Unsupported architecture");
}
}
MaterializationUnit::Interface SimpleMachOHeaderMU::createHeaderInterface(
MachOPlatform &MOP, const SymbolStringPtr &HeaderStartSymbol) {
SymbolFlagsMap HeaderSymbolFlags;
HeaderSymbolFlags[HeaderStartSymbol] = JITSymbolFlags::Exported;
for (auto &HS : AdditionalHeaderSymbols)
HeaderSymbolFlags[MOP.getExecutionSession().intern(HS.Name)] =
JITSymbolFlags::Exported;
return MaterializationUnit::Interface(std::move(HeaderSymbolFlags),
HeaderStartSymbol);
}
MachOHeaderInfo getMachOHeaderInfoFromTriple(const Triple &TT) {
switch (TT.getArch()) {
case Triple::aarch64:
return {/* PageSize = */ 16 * 1024,
/* CPUType = */ MachO::CPU_TYPE_ARM64,
/* CPUSubType = */ MachO::CPU_SUBTYPE_ARM64_ALL};
case Triple::x86_64:
return {/* PageSize = */ 4 * 1024,
/* CPUType = */ MachO::CPU_TYPE_X86_64,
/* CPUSubType = */ MachO::CPU_SUBTYPE_X86_64_ALL};
default:
llvm_unreachable("Unrecognized architecture");
}
}
} // End namespace orc.
} // End namespace llvm.