490 lines
17 KiB
C++
490 lines
17 KiB
C++
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//===------ MachOPlatform.cpp - Utilities for executing MachO in Orc ------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/ExecutionEngine/Orc/MachOPlatform.h"
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#include "llvm/BinaryFormat/MachO.h"
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#include "llvm/ExecutionEngine/Orc/DebugUtils.h"
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#include "llvm/Support/BinaryByteStream.h"
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#include "llvm/Support/Debug.h"
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#define DEBUG_TYPE "orc"
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namespace {
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struct objc_class;
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struct objc_image_info;
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struct objc_object;
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struct objc_selector;
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using Class = objc_class *;
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using id = objc_object *;
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using SEL = objc_selector *;
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using ObjCMsgSendTy = id (*)(id, SEL, ...);
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using ObjCReadClassPairTy = Class (*)(Class, const objc_image_info *);
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using SelRegisterNameTy = SEL (*)(const char *);
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enum class ObjCRegistrationAPI { Uninitialized, Unavailable, Initialized };
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ObjCRegistrationAPI ObjCRegistrationAPIState =
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ObjCRegistrationAPI::Uninitialized;
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ObjCMsgSendTy objc_msgSend = nullptr;
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ObjCReadClassPairTy objc_readClassPair = nullptr;
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SelRegisterNameTy sel_registerName = nullptr;
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} // end anonymous namespace
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namespace llvm {
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namespace orc {
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template <typename FnTy>
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static Error setUpObjCRegAPIFunc(FnTy &Target, sys::DynamicLibrary &LibObjC,
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const char *Name) {
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if (void *Addr = LibObjC.getAddressOfSymbol(Name))
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Target = reinterpret_cast<FnTy>(Addr);
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else
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return make_error<StringError>(
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(Twine("Could not find address for ") + Name).str(),
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inconvertibleErrorCode());
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return Error::success();
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}
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Error enableObjCRegistration(const char *PathToLibObjC) {
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// If we've already tried to initialize then just bail out.
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if (ObjCRegistrationAPIState != ObjCRegistrationAPI::Uninitialized)
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return Error::success();
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ObjCRegistrationAPIState = ObjCRegistrationAPI::Unavailable;
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std::string ErrMsg;
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auto LibObjC =
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sys::DynamicLibrary::getPermanentLibrary(PathToLibObjC, &ErrMsg);
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if (!LibObjC.isValid())
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return make_error<StringError>(std::move(ErrMsg), inconvertibleErrorCode());
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if (auto Err = setUpObjCRegAPIFunc(objc_msgSend, LibObjC, "objc_msgSend"))
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return Err;
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if (auto Err = setUpObjCRegAPIFunc(objc_readClassPair, LibObjC,
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"objc_readClassPair"))
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return Err;
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if (auto Err =
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setUpObjCRegAPIFunc(sel_registerName, LibObjC, "sel_registerName"))
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return Err;
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ObjCRegistrationAPIState = ObjCRegistrationAPI::Initialized;
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return Error::success();
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}
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bool objCRegistrationEnabled() {
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return ObjCRegistrationAPIState == ObjCRegistrationAPI::Initialized;
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}
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void MachOJITDylibInitializers::runModInits() const {
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for (const auto &ModInit : ModInitSections) {
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for (uint64_t I = 0; I != ModInit.NumPtrs; ++I) {
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auto *InitializerAddr = jitTargetAddressToPointer<uintptr_t *>(
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ModInit.Address + (I * sizeof(uintptr_t)));
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auto *Initializer =
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jitTargetAddressToFunction<void (*)()>(*InitializerAddr);
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Initializer();
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}
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}
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}
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void MachOJITDylibInitializers::registerObjCSelectors() const {
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assert(objCRegistrationEnabled() && "ObjC registration not enabled.");
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for (const auto &ObjCSelRefs : ObjCSelRefsSections) {
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for (uint64_t I = 0; I != ObjCSelRefs.NumPtrs; ++I) {
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auto SelEntryAddr = ObjCSelRefs.Address + (I * sizeof(uintptr_t));
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const auto *SelName =
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*jitTargetAddressToPointer<const char **>(SelEntryAddr);
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auto Sel = sel_registerName(SelName);
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*jitTargetAddressToPointer<SEL *>(SelEntryAddr) = Sel;
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}
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}
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}
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Error MachOJITDylibInitializers::registerObjCClasses() const {
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assert(objCRegistrationEnabled() && "ObjC registration not enabled.");
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struct ObjCClassCompiled {
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void *Metaclass;
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void *Parent;
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void *Cache1;
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void *Cache2;
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void *Data;
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};
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auto *ImageInfo =
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jitTargetAddressToPointer<const objc_image_info *>(ObjCImageInfoAddr);
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auto ClassSelector = sel_registerName("class");
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for (const auto &ObjCClassList : ObjCClassListSections) {
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for (uint64_t I = 0; I != ObjCClassList.NumPtrs; ++I) {
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auto ClassPtrAddr = ObjCClassList.Address + (I * sizeof(uintptr_t));
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auto Cls = *jitTargetAddressToPointer<Class *>(ClassPtrAddr);
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auto *ClassCompiled =
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*jitTargetAddressToPointer<ObjCClassCompiled **>(ClassPtrAddr);
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objc_msgSend(reinterpret_cast<id>(ClassCompiled->Parent), ClassSelector);
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auto Registered = objc_readClassPair(Cls, ImageInfo);
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// FIXME: Improve diagnostic by reporting the failed class's name.
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if (Registered != Cls)
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return make_error<StringError>("Unable to register Objective-C class",
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inconvertibleErrorCode());
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}
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}
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return Error::success();
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}
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MachOPlatform::MachOPlatform(
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ExecutionSession &ES, ObjectLinkingLayer &ObjLinkingLayer,
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std::unique_ptr<MemoryBuffer> StandardSymbolsObject)
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: ES(ES), ObjLinkingLayer(ObjLinkingLayer),
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StandardSymbolsObject(std::move(StandardSymbolsObject)) {
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ObjLinkingLayer.addPlugin(std::make_unique<InitScraperPlugin>(*this));
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}
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Error MachOPlatform::setupJITDylib(JITDylib &JD) {
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auto ObjBuffer = MemoryBuffer::getMemBuffer(
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StandardSymbolsObject->getMemBufferRef(), false);
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return ObjLinkingLayer.add(JD, std::move(ObjBuffer));
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}
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Error MachOPlatform::notifyAdding(ResourceTracker &RT,
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const MaterializationUnit &MU) {
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auto &JD = RT.getJITDylib();
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const auto &InitSym = MU.getInitializerSymbol();
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if (!InitSym)
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return Error::success();
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RegisteredInitSymbols[&JD].add(InitSym,
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SymbolLookupFlags::WeaklyReferencedSymbol);
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LLVM_DEBUG({
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dbgs() << "MachOPlatform: Registered init symbol " << *InitSym << " for MU "
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<< MU.getName() << "\n";
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});
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return Error::success();
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}
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Error MachOPlatform::notifyRemoving(ResourceTracker &RT) {
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llvm_unreachable("Not supported yet");
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}
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Expected<MachOPlatform::InitializerSequence>
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MachOPlatform::getInitializerSequence(JITDylib &JD) {
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LLVM_DEBUG({
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dbgs() << "MachOPlatform: Building initializer sequence for "
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<< JD.getName() << "\n";
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});
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std::vector<JITDylibSP> DFSLinkOrder;
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while (true) {
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DenseMap<JITDylib *, SymbolLookupSet> NewInitSymbols;
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ES.runSessionLocked([&]() {
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DFSLinkOrder = JD.getDFSLinkOrder();
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for (auto &InitJD : DFSLinkOrder) {
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auto RISItr = RegisteredInitSymbols.find(InitJD.get());
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if (RISItr != RegisteredInitSymbols.end()) {
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NewInitSymbols[InitJD.get()] = std::move(RISItr->second);
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RegisteredInitSymbols.erase(RISItr);
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}
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}
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});
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if (NewInitSymbols.empty())
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break;
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LLVM_DEBUG({
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dbgs() << "MachOPlatform: Issuing lookups for new init symbols: "
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"(lookup may require multiple rounds)\n";
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for (auto &KV : NewInitSymbols)
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dbgs() << " \"" << KV.first->getName() << "\": " << KV.second << "\n";
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});
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// Outside the lock, issue the lookup.
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if (auto R = lookupInitSymbols(JD.getExecutionSession(), NewInitSymbols))
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; // Nothing to do in the success case.
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else
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return R.takeError();
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}
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LLVM_DEBUG({
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dbgs() << "MachOPlatform: Init symbol lookup complete, building init "
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"sequence\n";
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});
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// Lock again to collect the initializers.
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InitializerSequence FullInitSeq;
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{
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std::lock_guard<std::mutex> Lock(InitSeqsMutex);
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for (auto &InitJD : reverse(DFSLinkOrder)) {
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LLVM_DEBUG({
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dbgs() << "MachOPlatform: Appending inits for \"" << InitJD->getName()
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<< "\" to sequence\n";
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});
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auto ISItr = InitSeqs.find(InitJD.get());
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if (ISItr != InitSeqs.end()) {
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FullInitSeq.emplace_back(InitJD.get(), std::move(ISItr->second));
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InitSeqs.erase(ISItr);
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}
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}
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}
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return FullInitSeq;
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}
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Expected<MachOPlatform::DeinitializerSequence>
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MachOPlatform::getDeinitializerSequence(JITDylib &JD) {
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std::vector<JITDylibSP> DFSLinkOrder = JD.getDFSLinkOrder();
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DeinitializerSequence FullDeinitSeq;
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{
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std::lock_guard<std::mutex> Lock(InitSeqsMutex);
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for (auto &DeinitJD : DFSLinkOrder) {
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FullDeinitSeq.emplace_back(DeinitJD.get(), MachOJITDylibDeinitializers());
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}
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}
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return FullDeinitSeq;
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}
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void MachOPlatform::registerInitInfo(
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JITDylib &JD, JITTargetAddress ObjCImageInfoAddr,
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MachOJITDylibInitializers::SectionExtent ModInits,
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MachOJITDylibInitializers::SectionExtent ObjCSelRefs,
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MachOJITDylibInitializers::SectionExtent ObjCClassList) {
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std::lock_guard<std::mutex> Lock(InitSeqsMutex);
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auto &InitSeq = InitSeqs[&JD];
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InitSeq.setObjCImageInfoAddr(ObjCImageInfoAddr);
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if (ModInits.Address)
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InitSeq.addModInitsSection(std::move(ModInits));
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if (ObjCSelRefs.Address)
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InitSeq.addObjCSelRefsSection(std::move(ObjCSelRefs));
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if (ObjCClassList.Address)
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InitSeq.addObjCClassListSection(std::move(ObjCClassList));
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}
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static Expected<MachOJITDylibInitializers::SectionExtent>
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getSectionExtent(jitlink::LinkGraph &G, StringRef SectionName) {
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auto *Sec = G.findSectionByName(SectionName);
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if (!Sec)
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return MachOJITDylibInitializers::SectionExtent();
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jitlink::SectionRange R(*Sec);
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if (R.getSize() % G.getPointerSize() != 0)
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return make_error<StringError>(SectionName + " section size is not a "
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"multiple of the pointer size",
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inconvertibleErrorCode());
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return MachOJITDylibInitializers::SectionExtent(
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R.getStart(), R.getSize() / G.getPointerSize());
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}
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void MachOPlatform::InitScraperPlugin::modifyPassConfig(
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MaterializationResponsibility &MR, const Triple &TT,
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jitlink::PassConfiguration &Config) {
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if (!MR.getInitializerSymbol())
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return;
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Config.PrePrunePasses.push_back([this, &MR](jitlink::LinkGraph &G) -> Error {
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JITLinkSymbolVector InitSectionSymbols;
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preserveInitSectionIfPresent(InitSectionSymbols, G, "__mod_init_func");
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preserveInitSectionIfPresent(InitSectionSymbols, G, "__objc_selrefs");
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preserveInitSectionIfPresent(InitSectionSymbols, G, "__objc_classlist");
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if (!InitSectionSymbols.empty()) {
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std::lock_guard<std::mutex> Lock(InitScraperMutex);
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InitSymbolDeps[&MR] = std::move(InitSectionSymbols);
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}
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if (auto Err = processObjCImageInfo(G, MR))
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return Err;
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return Error::success();
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});
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Config.PostFixupPasses.push_back([this, &JD = MR.getTargetJITDylib()](
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jitlink::LinkGraph &G) -> Error {
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MachOJITDylibInitializers::SectionExtent ModInits, ObjCSelRefs,
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ObjCClassList;
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JITTargetAddress ObjCImageInfoAddr = 0;
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if (auto *ObjCImageInfoSec = G.findSectionByName("__objc_image_info")) {
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if (auto Addr = jitlink::SectionRange(*ObjCImageInfoSec).getStart())
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ObjCImageInfoAddr = Addr;
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}
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// Record __mod_init_func.
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if (auto ModInitsOrErr = getSectionExtent(G, "__mod_init_func"))
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ModInits = std::move(*ModInitsOrErr);
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else
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return ModInitsOrErr.takeError();
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// Record __objc_selrefs.
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if (auto ObjCSelRefsOrErr = getSectionExtent(G, "__objc_selrefs"))
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ObjCSelRefs = std::move(*ObjCSelRefsOrErr);
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else
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return ObjCSelRefsOrErr.takeError();
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// Record __objc_classlist.
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if (auto ObjCClassListOrErr = getSectionExtent(G, "__objc_classlist"))
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ObjCClassList = std::move(*ObjCClassListOrErr);
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else
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return ObjCClassListOrErr.takeError();
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// Dump the scraped inits.
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LLVM_DEBUG({
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dbgs() << "MachOPlatform: Scraped " << G.getName() << " init sections:\n";
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dbgs() << " __objc_selrefs: ";
|
||
|
|
if (ObjCSelRefs.NumPtrs)
|
||
|
|
dbgs() << ObjCSelRefs.NumPtrs << " pointer(s) at "
|
||
|
|
<< formatv("{0:x16}", ObjCSelRefs.Address) << "\n";
|
||
|
|
else
|
||
|
|
dbgs() << "none\n";
|
||
|
|
|
||
|
|
dbgs() << " __objc_classlist: ";
|
||
|
|
if (ObjCClassList.NumPtrs)
|
||
|
|
dbgs() << ObjCClassList.NumPtrs << " pointer(s) at "
|
||
|
|
<< formatv("{0:x16}", ObjCClassList.Address) << "\n";
|
||
|
|
else
|
||
|
|
dbgs() << "none\n";
|
||
|
|
|
||
|
|
dbgs() << " __mod_init_func: ";
|
||
|
|
if (ModInits.NumPtrs)
|
||
|
|
dbgs() << ModInits.NumPtrs << " pointer(s) at "
|
||
|
|
<< formatv("{0:x16}", ModInits.Address) << "\n";
|
||
|
|
else
|
||
|
|
dbgs() << "none\n";
|
||
|
|
});
|
||
|
|
|
||
|
|
MP.registerInitInfo(JD, ObjCImageInfoAddr, std::move(ModInits),
|
||
|
|
std::move(ObjCSelRefs), std::move(ObjCClassList));
|
||
|
|
|
||
|
|
return Error::success();
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
ObjectLinkingLayer::Plugin::LocalDependenciesMap
|
||
|
|
MachOPlatform::InitScraperPlugin::getSyntheticSymbolLocalDependencies(
|
||
|
|
MaterializationResponsibility &MR) {
|
||
|
|
std::lock_guard<std::mutex> Lock(InitScraperMutex);
|
||
|
|
auto I = InitSymbolDeps.find(&MR);
|
||
|
|
if (I != InitSymbolDeps.end()) {
|
||
|
|
LocalDependenciesMap Result;
|
||
|
|
Result[MR.getInitializerSymbol()] = std::move(I->second);
|
||
|
|
InitSymbolDeps.erase(&MR);
|
||
|
|
return Result;
|
||
|
|
}
|
||
|
|
return LocalDependenciesMap();
|
||
|
|
}
|
||
|
|
|
||
|
|
void MachOPlatform::InitScraperPlugin::preserveInitSectionIfPresent(
|
||
|
|
JITLinkSymbolVector &Symbols, jitlink::LinkGraph &G,
|
||
|
|
StringRef SectionName) {
|
||
|
|
if (auto *Sec = G.findSectionByName(SectionName)) {
|
||
|
|
auto SecBlocks = Sec->blocks();
|
||
|
|
if (!llvm::empty(SecBlocks))
|
||
|
|
Symbols.push_back(
|
||
|
|
&G.addAnonymousSymbol(**SecBlocks.begin(), 0, 0, false, true));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
Error MachOPlatform::InitScraperPlugin::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("__objc_imageinfo");
|
||
|
|
if (!ObjCImageInfo)
|
||
|
|
return Error::success();
|
||
|
|
|
||
|
|
auto ObjCImageInfoBlocks = ObjCImageInfo->blocks();
|
||
|
|
|
||
|
|
// Check that the section is not empty if present.
|
||
|
|
if (llvm::empty(ObjCImageInfoBlocks))
|
||
|
|
return make_error<StringError>("Empty __objc_imageinfo 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 __objc_imageinfo "
|
||
|
|
"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>("__objc_imageinfo 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(InitScraperMutex);
|
||
|
|
|
||
|
|
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.first != Version)
|
||
|
|
return make_error<StringError>(
|
||
|
|
"ObjC version in " + G.getName() +
|
||
|
|
" does not match first registered version",
|
||
|
|
inconvertibleErrorCode());
|
||
|
|
if (ObjCImageInfoItr->second.second != Flags)
|
||
|
|
return make_error<StringError>("ObjC flags in " + G.getName() +
|
||
|
|
" do not match first registered flags",
|
||
|
|
inconvertibleErrorCode());
|
||
|
|
|
||
|
|
// __objc_imageinfo is valid. Delete the block.
|
||
|
|
for (auto *S : ObjCImageInfo->symbols())
|
||
|
|
G.removeDefinedSymbol(*S);
|
||
|
|
G.removeBlock(ObjCImageInfoBlock);
|
||
|
|
} else {
|
||
|
|
// We haven't registered an __objc_imageinfo section yet. Register and
|
||
|
|
// move on. The section should already be marked no-dead-strip.
|
||
|
|
ObjCImageInfos[&MR.getTargetJITDylib()] = std::make_pair(Version, Flags);
|
||
|
|
}
|
||
|
|
|
||
|
|
return Error::success();
|
||
|
|
}
|
||
|
|
|
||
|
|
} // End namespace orc.
|
||
|
|
} // End namespace llvm.
|