mirror of
https://github.com/c64scene-ar/llvm-6502.git
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9327084f92
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241603 91177308-0d34-0410-b5e6-96231b3b80d8
942 lines
34 KiB
C++
942 lines
34 KiB
C++
//===-- RuntimeDyld.cpp - Run-time dynamic linker for MC-JIT ----*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// Implementation of the MC-JIT runtime dynamic linker.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/ExecutionEngine/RuntimeDyld.h"
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#include "RuntimeDyldCheckerImpl.h"
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#include "RuntimeDyldCOFF.h"
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#include "RuntimeDyldELF.h"
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#include "RuntimeDyldImpl.h"
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#include "RuntimeDyldMachO.h"
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#include "llvm/Object/ELFObjectFile.h"
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#include "llvm/Object/COFF.h"
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#include "llvm/Support/MathExtras.h"
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#include "llvm/Support/MutexGuard.h"
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using namespace llvm;
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using namespace llvm::object;
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#define DEBUG_TYPE "dyld"
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// Empty out-of-line virtual destructor as the key function.
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RuntimeDyldImpl::~RuntimeDyldImpl() {}
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// Pin LoadedObjectInfo's vtables to this file.
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void RuntimeDyld::LoadedObjectInfo::anchor() {}
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namespace llvm {
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void RuntimeDyldImpl::registerEHFrames() {}
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void RuntimeDyldImpl::deregisterEHFrames() {}
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#ifndef NDEBUG
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static void dumpSectionMemory(const SectionEntry &S, StringRef State) {
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dbgs() << "----- Contents of section " << S.Name << " " << State << " -----";
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if (S.Address == nullptr) {
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dbgs() << "\n <section not emitted>\n";
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return;
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}
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const unsigned ColsPerRow = 16;
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uint8_t *DataAddr = S.Address;
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uint64_t LoadAddr = S.LoadAddress;
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unsigned StartPadding = LoadAddr & (ColsPerRow - 1);
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unsigned BytesRemaining = S.Size;
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if (StartPadding) {
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dbgs() << "\n" << format("0x%016" PRIx64,
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LoadAddr & ~(uint64_t)(ColsPerRow - 1)) << ":";
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while (StartPadding--)
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dbgs() << " ";
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}
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while (BytesRemaining > 0) {
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if ((LoadAddr & (ColsPerRow - 1)) == 0)
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dbgs() << "\n" << format("0x%016" PRIx64, LoadAddr) << ":";
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dbgs() << " " << format("%02x", *DataAddr);
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++DataAddr;
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++LoadAddr;
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--BytesRemaining;
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}
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dbgs() << "\n";
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}
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#endif
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// Resolve the relocations for all symbols we currently know about.
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void RuntimeDyldImpl::resolveRelocations() {
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MutexGuard locked(lock);
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// First, resolve relocations associated with external symbols.
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resolveExternalSymbols();
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// Just iterate over the sections we have and resolve all the relocations
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// in them. Gross overkill, but it gets the job done.
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for (int i = 0, e = Sections.size(); i != e; ++i) {
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// The Section here (Sections[i]) refers to the section in which the
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// symbol for the relocation is located. The SectionID in the relocation
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// entry provides the section to which the relocation will be applied.
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uint64_t Addr = Sections[i].LoadAddress;
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DEBUG(dbgs() << "Resolving relocations Section #" << i << "\t"
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<< format("%p", (uintptr_t)Addr) << "\n");
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DEBUG(dumpSectionMemory(Sections[i], "before relocations"));
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resolveRelocationList(Relocations[i], Addr);
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DEBUG(dumpSectionMemory(Sections[i], "after relocations"));
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Relocations.erase(i);
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}
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}
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void RuntimeDyldImpl::mapSectionAddress(const void *LocalAddress,
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uint64_t TargetAddress) {
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MutexGuard locked(lock);
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for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
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if (Sections[i].Address == LocalAddress) {
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reassignSectionAddress(i, TargetAddress);
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return;
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}
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}
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llvm_unreachable("Attempting to remap address of unknown section!");
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}
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static std::error_code getOffset(const SymbolRef &Sym, SectionRef Sec,
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uint64_t &Result) {
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ErrorOr<uint64_t> AddressOrErr = Sym.getAddress();
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if (std::error_code EC = AddressOrErr.getError())
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return EC;
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Result = *AddressOrErr - Sec.getAddress();
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return std::error_code();
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}
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std::pair<unsigned, unsigned>
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RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
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MutexGuard locked(lock);
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// Grab the first Section ID. We'll use this later to construct the underlying
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// range for the returned LoadedObjectInfo.
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unsigned SectionsAddedBeginIdx = Sections.size();
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// Save information about our target
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Arch = (Triple::ArchType)Obj.getArch();
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IsTargetLittleEndian = Obj.isLittleEndian();
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setMipsABI(Obj);
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// Compute the memory size required to load all sections to be loaded
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// and pass this information to the memory manager
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if (MemMgr.needsToReserveAllocationSpace()) {
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uint64_t CodeSize = 0, DataSizeRO = 0, DataSizeRW = 0;
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computeTotalAllocSize(Obj, CodeSize, DataSizeRO, DataSizeRW);
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MemMgr.reserveAllocationSpace(CodeSize, DataSizeRO, DataSizeRW);
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}
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// Used sections from the object file
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ObjSectionToIDMap LocalSections;
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// Common symbols requiring allocation, with their sizes and alignments
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CommonSymbolList CommonSymbols;
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// Parse symbols
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DEBUG(dbgs() << "Parse symbols:\n");
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for (symbol_iterator I = Obj.symbol_begin(), E = Obj.symbol_end(); I != E;
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++I) {
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uint32_t Flags = I->getFlags();
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bool IsCommon = Flags & SymbolRef::SF_Common;
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if (IsCommon)
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CommonSymbols.push_back(*I);
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else {
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object::SymbolRef::Type SymType = I->getType();
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if (SymType == object::SymbolRef::ST_Function ||
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SymType == object::SymbolRef::ST_Data ||
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SymType == object::SymbolRef::ST_Unknown) {
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ErrorOr<StringRef> NameOrErr = I->getName();
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Check(NameOrErr.getError());
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StringRef Name = *NameOrErr;
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section_iterator SI = Obj.section_end();
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Check(I->getSection(SI));
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if (SI == Obj.section_end())
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continue;
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uint64_t SectOffset;
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Check(getOffset(*I, *SI, SectOffset));
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StringRef SectionData;
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Check(SI->getContents(SectionData));
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bool IsCode = SI->isText();
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unsigned SectionID =
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findOrEmitSection(Obj, *SI, IsCode, LocalSections);
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DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name
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<< " SID: " << SectionID << " Offset: "
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<< format("%p", (uintptr_t)SectOffset)
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<< " flags: " << Flags << "\n");
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JITSymbolFlags RTDyldSymFlags = JITSymbolFlags::None;
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if (Flags & SymbolRef::SF_Weak)
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RTDyldSymFlags |= JITSymbolFlags::Weak;
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if (Flags & SymbolRef::SF_Exported)
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RTDyldSymFlags |= JITSymbolFlags::Exported;
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GlobalSymbolTable[Name] =
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SymbolTableEntry(SectionID, SectOffset, RTDyldSymFlags);
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}
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}
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}
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// Allocate common symbols
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emitCommonSymbols(Obj, CommonSymbols);
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// Parse and process relocations
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DEBUG(dbgs() << "Parse relocations:\n");
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for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
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SI != SE; ++SI) {
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unsigned SectionID = 0;
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StubMap Stubs;
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section_iterator RelocatedSection = SI->getRelocatedSection();
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if (RelocatedSection == SE)
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continue;
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relocation_iterator I = SI->relocation_begin();
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relocation_iterator E = SI->relocation_end();
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if (I == E && !ProcessAllSections)
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continue;
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bool IsCode = RelocatedSection->isText();
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SectionID =
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findOrEmitSection(Obj, *RelocatedSection, IsCode, LocalSections);
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DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n");
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for (; I != E;)
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I = processRelocationRef(SectionID, I, Obj, LocalSections, Stubs);
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// If there is an attached checker, notify it about the stubs for this
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// section so that they can be verified.
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if (Checker)
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Checker->registerStubMap(Obj.getFileName(), SectionID, Stubs);
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}
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// Give the subclasses a chance to tie-up any loose ends.
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finalizeLoad(Obj, LocalSections);
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unsigned SectionsAddedEndIdx = Sections.size();
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return std::make_pair(SectionsAddedBeginIdx, SectionsAddedEndIdx);
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}
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// A helper method for computeTotalAllocSize.
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// Computes the memory size required to allocate sections with the given sizes,
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// assuming that all sections are allocated with the given alignment
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static uint64_t
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computeAllocationSizeForSections(std::vector<uint64_t> &SectionSizes,
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uint64_t Alignment) {
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uint64_t TotalSize = 0;
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for (size_t Idx = 0, Cnt = SectionSizes.size(); Idx < Cnt; Idx++) {
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uint64_t AlignedSize =
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(SectionSizes[Idx] + Alignment - 1) / Alignment * Alignment;
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TotalSize += AlignedSize;
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}
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return TotalSize;
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}
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static bool isRequiredForExecution(const SectionRef Section) {
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const ObjectFile *Obj = Section.getObject();
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if (isa<object::ELFObjectFileBase>(Obj))
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return ELFSectionRef(Section).getFlags() & ELF::SHF_ALLOC;
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if (auto *COFFObj = dyn_cast<object::COFFObjectFile>(Obj)) {
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const coff_section *CoffSection = COFFObj->getCOFFSection(Section);
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// Avoid loading zero-sized COFF sections.
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// In PE files, VirtualSize gives the section size, and SizeOfRawData
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// may be zero for sections with content. In Obj files, SizeOfRawData
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// gives the section size, and VirtualSize is always zero. Hence
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// the need to check for both cases below.
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bool HasContent = (CoffSection->VirtualSize > 0)
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|| (CoffSection->SizeOfRawData > 0);
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bool IsDiscardable = CoffSection->Characteristics &
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(COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_LNK_INFO);
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return HasContent && !IsDiscardable;
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}
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assert(isa<MachOObjectFile>(Obj));
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return true;
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}
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static bool isReadOnlyData(const SectionRef Section) {
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const ObjectFile *Obj = Section.getObject();
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if (isa<object::ELFObjectFileBase>(Obj))
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return !(ELFSectionRef(Section).getFlags() &
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(ELF::SHF_WRITE | ELF::SHF_EXECINSTR));
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if (auto *COFFObj = dyn_cast<object::COFFObjectFile>(Obj))
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return ((COFFObj->getCOFFSection(Section)->Characteristics &
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(COFF::IMAGE_SCN_CNT_INITIALIZED_DATA
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| COFF::IMAGE_SCN_MEM_READ
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| COFF::IMAGE_SCN_MEM_WRITE))
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==
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(COFF::IMAGE_SCN_CNT_INITIALIZED_DATA
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| COFF::IMAGE_SCN_MEM_READ));
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assert(isa<MachOObjectFile>(Obj));
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return false;
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}
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static bool isZeroInit(const SectionRef Section) {
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const ObjectFile *Obj = Section.getObject();
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if (isa<object::ELFObjectFileBase>(Obj))
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return ELFSectionRef(Section).getType() == ELF::SHT_NOBITS;
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if (auto *COFFObj = dyn_cast<object::COFFObjectFile>(Obj))
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return COFFObj->getCOFFSection(Section)->Characteristics &
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COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA;
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auto *MachO = cast<MachOObjectFile>(Obj);
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unsigned SectionType = MachO->getSectionType(Section);
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return SectionType == MachO::S_ZEROFILL ||
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SectionType == MachO::S_GB_ZEROFILL;
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}
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// Compute an upper bound of the memory size that is required to load all
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// sections
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void RuntimeDyldImpl::computeTotalAllocSize(const ObjectFile &Obj,
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uint64_t &CodeSize,
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uint64_t &DataSizeRO,
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uint64_t &DataSizeRW) {
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// Compute the size of all sections required for execution
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std::vector<uint64_t> CodeSectionSizes;
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std::vector<uint64_t> ROSectionSizes;
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std::vector<uint64_t> RWSectionSizes;
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uint64_t MaxAlignment = sizeof(void *);
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// Collect sizes of all sections to be loaded;
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// also determine the max alignment of all sections
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for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
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SI != SE; ++SI) {
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const SectionRef &Section = *SI;
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bool IsRequired = isRequiredForExecution(Section);
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// Consider only the sections that are required to be loaded for execution
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if (IsRequired) {
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StringRef Name;
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uint64_t DataSize = Section.getSize();
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uint64_t Alignment64 = Section.getAlignment();
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bool IsCode = Section.isText();
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bool IsReadOnly = isReadOnlyData(Section);
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Check(Section.getName(Name));
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unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
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uint64_t StubBufSize = computeSectionStubBufSize(Obj, Section);
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uint64_t SectionSize = DataSize + StubBufSize;
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// The .eh_frame section (at least on Linux) needs an extra four bytes
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// padded
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// with zeroes added at the end. For MachO objects, this section has a
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// slightly different name, so this won't have any effect for MachO
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// objects.
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if (Name == ".eh_frame")
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SectionSize += 4;
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if (!SectionSize)
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SectionSize = 1;
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if (IsCode) {
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CodeSectionSizes.push_back(SectionSize);
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} else if (IsReadOnly) {
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ROSectionSizes.push_back(SectionSize);
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} else {
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RWSectionSizes.push_back(SectionSize);
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}
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// update the max alignment
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if (Alignment > MaxAlignment) {
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MaxAlignment = Alignment;
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}
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}
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}
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// Compute the size of all common symbols
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uint64_t CommonSize = 0;
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for (symbol_iterator I = Obj.symbol_begin(), E = Obj.symbol_end(); I != E;
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++I) {
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uint32_t Flags = I->getFlags();
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if (Flags & SymbolRef::SF_Common) {
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// Add the common symbols to a list. We'll allocate them all below.
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uint64_t Size = I->getCommonSize();
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CommonSize += Size;
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}
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}
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if (CommonSize != 0) {
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RWSectionSizes.push_back(CommonSize);
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}
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// Compute the required allocation space for each different type of sections
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// (code, read-only data, read-write data) assuming that all sections are
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// allocated with the max alignment. Note that we cannot compute with the
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// individual alignments of the sections, because then the required size
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// depends on the order, in which the sections are allocated.
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CodeSize = computeAllocationSizeForSections(CodeSectionSizes, MaxAlignment);
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DataSizeRO = computeAllocationSizeForSections(ROSectionSizes, MaxAlignment);
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DataSizeRW = computeAllocationSizeForSections(RWSectionSizes, MaxAlignment);
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}
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// compute stub buffer size for the given section
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unsigned RuntimeDyldImpl::computeSectionStubBufSize(const ObjectFile &Obj,
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const SectionRef &Section) {
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unsigned StubSize = getMaxStubSize();
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if (StubSize == 0) {
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return 0;
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}
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// FIXME: this is an inefficient way to handle this. We should computed the
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// necessary section allocation size in loadObject by walking all the sections
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// once.
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unsigned StubBufSize = 0;
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for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
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SI != SE; ++SI) {
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section_iterator RelSecI = SI->getRelocatedSection();
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if (!(RelSecI == Section))
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continue;
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for (const RelocationRef &Reloc : SI->relocations()) {
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(void)Reloc;
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StubBufSize += StubSize;
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}
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}
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// Get section data size and alignment
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uint64_t DataSize = Section.getSize();
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uint64_t Alignment64 = Section.getAlignment();
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// Add stubbuf size alignment
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unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
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unsigned StubAlignment = getStubAlignment();
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unsigned EndAlignment = (DataSize | Alignment) & -(DataSize | Alignment);
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if (StubAlignment > EndAlignment)
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StubBufSize += StubAlignment - EndAlignment;
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return StubBufSize;
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}
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uint64_t RuntimeDyldImpl::readBytesUnaligned(uint8_t *Src,
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unsigned Size) const {
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uint64_t Result = 0;
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if (IsTargetLittleEndian) {
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Src += Size - 1;
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while (Size--)
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Result = (Result << 8) | *Src--;
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} else
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while (Size--)
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Result = (Result << 8) | *Src++;
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return Result;
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}
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void RuntimeDyldImpl::writeBytesUnaligned(uint64_t Value, uint8_t *Dst,
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unsigned Size) const {
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if (IsTargetLittleEndian) {
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while (Size--) {
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*Dst++ = Value & 0xFF;
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Value >>= 8;
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}
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} else {
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Dst += Size - 1;
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while (Size--) {
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*Dst-- = Value & 0xFF;
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Value >>= 8;
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}
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}
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}
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void RuntimeDyldImpl::emitCommonSymbols(const ObjectFile &Obj,
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CommonSymbolList &CommonSymbols) {
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if (CommonSymbols.empty())
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return;
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uint64_t CommonSize = 0;
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CommonSymbolList SymbolsToAllocate;
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DEBUG(dbgs() << "Processing common symbols...\n");
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for (const auto &Sym : CommonSymbols) {
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ErrorOr<StringRef> NameOrErr = Sym.getName();
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Check(NameOrErr.getError());
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StringRef Name = *NameOrErr;
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// Skip common symbols already elsewhere.
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if (GlobalSymbolTable.count(Name) ||
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Resolver.findSymbolInLogicalDylib(Name)) {
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DEBUG(dbgs() << "\tSkipping already emitted common symbol '" << Name
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<< "'\n");
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continue;
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}
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uint32_t Align = Sym.getAlignment();
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uint64_t Size = Sym.getCommonSize();
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CommonSize += Align + Size;
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SymbolsToAllocate.push_back(Sym);
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}
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// Allocate memory for the section
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unsigned SectionID = Sections.size();
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uint8_t *Addr = MemMgr.allocateDataSection(CommonSize, sizeof(void *),
|
|
SectionID, StringRef(), false);
|
|
if (!Addr)
|
|
report_fatal_error("Unable to allocate memory for common symbols!");
|
|
uint64_t Offset = 0;
|
|
Sections.push_back(SectionEntry("<common symbols>", Addr, CommonSize, 0));
|
|
memset(Addr, 0, CommonSize);
|
|
|
|
DEBUG(dbgs() << "emitCommonSection SectionID: " << SectionID << " new addr: "
|
|
<< format("%p", Addr) << " DataSize: " << CommonSize << "\n");
|
|
|
|
// Assign the address of each symbol
|
|
for (auto &Sym : SymbolsToAllocate) {
|
|
uint32_t Align = Sym.getAlignment();
|
|
uint64_t Size = Sym.getCommonSize();
|
|
ErrorOr<StringRef> NameOrErr = Sym.getName();
|
|
Check(NameOrErr.getError());
|
|
StringRef Name = *NameOrErr;
|
|
if (Align) {
|
|
// This symbol has an alignment requirement.
|
|
uint64_t AlignOffset = OffsetToAlignment((uint64_t)Addr, Align);
|
|
Addr += AlignOffset;
|
|
Offset += AlignOffset;
|
|
}
|
|
uint32_t Flags = Sym.getFlags();
|
|
JITSymbolFlags RTDyldSymFlags = JITSymbolFlags::None;
|
|
if (Flags & SymbolRef::SF_Weak)
|
|
RTDyldSymFlags |= JITSymbolFlags::Weak;
|
|
if (Flags & SymbolRef::SF_Exported)
|
|
RTDyldSymFlags |= JITSymbolFlags::Exported;
|
|
DEBUG(dbgs() << "Allocating common symbol " << Name << " address "
|
|
<< format("%p", Addr) << "\n");
|
|
GlobalSymbolTable[Name] =
|
|
SymbolTableEntry(SectionID, Offset, RTDyldSymFlags);
|
|
Offset += Size;
|
|
Addr += Size;
|
|
}
|
|
}
|
|
|
|
unsigned RuntimeDyldImpl::emitSection(const ObjectFile &Obj,
|
|
const SectionRef &Section, bool IsCode) {
|
|
|
|
StringRef data;
|
|
uint64_t Alignment64 = Section.getAlignment();
|
|
|
|
unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
|
|
unsigned PaddingSize = 0;
|
|
unsigned StubBufSize = 0;
|
|
StringRef Name;
|
|
bool IsRequired = isRequiredForExecution(Section);
|
|
bool IsVirtual = Section.isVirtual();
|
|
bool IsZeroInit = isZeroInit(Section);
|
|
bool IsReadOnly = isReadOnlyData(Section);
|
|
uint64_t DataSize = Section.getSize();
|
|
Check(Section.getName(Name));
|
|
|
|
StubBufSize = computeSectionStubBufSize(Obj, Section);
|
|
|
|
// The .eh_frame section (at least on Linux) needs an extra four bytes padded
|
|
// with zeroes added at the end. For MachO objects, this section has a
|
|
// slightly different name, so this won't have any effect for MachO objects.
|
|
if (Name == ".eh_frame")
|
|
PaddingSize = 4;
|
|
|
|
uintptr_t Allocate;
|
|
unsigned SectionID = Sections.size();
|
|
uint8_t *Addr;
|
|
const char *pData = nullptr;
|
|
|
|
// In either case, set the location of the unrelocated section in memory,
|
|
// since we still process relocations for it even if we're not applying them.
|
|
Check(Section.getContents(data));
|
|
// Virtual sections have no data in the object image, so leave pData = 0
|
|
if (!IsVirtual)
|
|
pData = data.data();
|
|
|
|
// Some sections, such as debug info, don't need to be loaded for execution.
|
|
// Leave those where they are.
|
|
if (IsRequired) {
|
|
Allocate = DataSize + PaddingSize + StubBufSize;
|
|
if (!Allocate)
|
|
Allocate = 1;
|
|
Addr = IsCode ? MemMgr.allocateCodeSection(Allocate, Alignment, SectionID,
|
|
Name)
|
|
: MemMgr.allocateDataSection(Allocate, Alignment, SectionID,
|
|
Name, IsReadOnly);
|
|
if (!Addr)
|
|
report_fatal_error("Unable to allocate section memory!");
|
|
|
|
// Zero-initialize or copy the data from the image
|
|
if (IsZeroInit || IsVirtual)
|
|
memset(Addr, 0, DataSize);
|
|
else
|
|
memcpy(Addr, pData, DataSize);
|
|
|
|
// Fill in any extra bytes we allocated for padding
|
|
if (PaddingSize != 0) {
|
|
memset(Addr + DataSize, 0, PaddingSize);
|
|
// Update the DataSize variable so that the stub offset is set correctly.
|
|
DataSize += PaddingSize;
|
|
}
|
|
|
|
DEBUG(dbgs() << "emitSection SectionID: " << SectionID << " Name: " << Name
|
|
<< " obj addr: " << format("%p", pData)
|
|
<< " new addr: " << format("%p", Addr)
|
|
<< " DataSize: " << DataSize << " StubBufSize: " << StubBufSize
|
|
<< " Allocate: " << Allocate << "\n");
|
|
} else {
|
|
// Even if we didn't load the section, we need to record an entry for it
|
|
// to handle later processing (and by 'handle' I mean don't do anything
|
|
// with these sections).
|
|
Allocate = 0;
|
|
Addr = nullptr;
|
|
DEBUG(dbgs() << "emitSection SectionID: " << SectionID << " Name: " << Name
|
|
<< " obj addr: " << format("%p", data.data()) << " new addr: 0"
|
|
<< " DataSize: " << DataSize << " StubBufSize: " << StubBufSize
|
|
<< " Allocate: " << Allocate << "\n");
|
|
}
|
|
|
|
Sections.push_back(SectionEntry(Name, Addr, DataSize, (uintptr_t)pData));
|
|
|
|
if (Checker)
|
|
Checker->registerSection(Obj.getFileName(), SectionID);
|
|
|
|
return SectionID;
|
|
}
|
|
|
|
unsigned RuntimeDyldImpl::findOrEmitSection(const ObjectFile &Obj,
|
|
const SectionRef &Section,
|
|
bool IsCode,
|
|
ObjSectionToIDMap &LocalSections) {
|
|
|
|
unsigned SectionID = 0;
|
|
ObjSectionToIDMap::iterator i = LocalSections.find(Section);
|
|
if (i != LocalSections.end())
|
|
SectionID = i->second;
|
|
else {
|
|
SectionID = emitSection(Obj, Section, IsCode);
|
|
LocalSections[Section] = SectionID;
|
|
}
|
|
return SectionID;
|
|
}
|
|
|
|
void RuntimeDyldImpl::addRelocationForSection(const RelocationEntry &RE,
|
|
unsigned SectionID) {
|
|
Relocations[SectionID].push_back(RE);
|
|
}
|
|
|
|
void RuntimeDyldImpl::addRelocationForSymbol(const RelocationEntry &RE,
|
|
StringRef SymbolName) {
|
|
// Relocation by symbol. If the symbol is found in the global symbol table,
|
|
// create an appropriate section relocation. Otherwise, add it to
|
|
// ExternalSymbolRelocations.
|
|
RTDyldSymbolTable::const_iterator Loc = GlobalSymbolTable.find(SymbolName);
|
|
if (Loc == GlobalSymbolTable.end()) {
|
|
ExternalSymbolRelocations[SymbolName].push_back(RE);
|
|
} else {
|
|
// Copy the RE since we want to modify its addend.
|
|
RelocationEntry RECopy = RE;
|
|
const auto &SymInfo = Loc->second;
|
|
RECopy.Addend += SymInfo.getOffset();
|
|
Relocations[SymInfo.getSectionID()].push_back(RECopy);
|
|
}
|
|
}
|
|
|
|
uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr,
|
|
unsigned AbiVariant) {
|
|
if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be) {
|
|
// This stub has to be able to access the full address space,
|
|
// since symbol lookup won't necessarily find a handy, in-range,
|
|
// PLT stub for functions which could be anywhere.
|
|
// Stub can use ip0 (== x16) to calculate address
|
|
writeBytesUnaligned(0xd2e00010, Addr, 4); // movz ip0, #:abs_g3:<addr>
|
|
writeBytesUnaligned(0xf2c00010, Addr+4, 4); // movk ip0, #:abs_g2_nc:<addr>
|
|
writeBytesUnaligned(0xf2a00010, Addr+8, 4); // movk ip0, #:abs_g1_nc:<addr>
|
|
writeBytesUnaligned(0xf2800010, Addr+12, 4); // movk ip0, #:abs_g0_nc:<addr>
|
|
writeBytesUnaligned(0xd61f0200, Addr+16, 4); // br ip0
|
|
|
|
return Addr;
|
|
} else if (Arch == Triple::arm || Arch == Triple::armeb) {
|
|
// TODO: There is only ARM far stub now. We should add the Thumb stub,
|
|
// and stubs for branches Thumb - ARM and ARM - Thumb.
|
|
writeBytesUnaligned(0xe51ff004, Addr, 4); // ldr pc,<label>
|
|
return Addr + 4;
|
|
} else if (IsMipsO32ABI) {
|
|
// 0: 3c190000 lui t9,%hi(addr).
|
|
// 4: 27390000 addiu t9,t9,%lo(addr).
|
|
// 8: 03200008 jr t9.
|
|
// c: 00000000 nop.
|
|
const unsigned LuiT9Instr = 0x3c190000, AdduiT9Instr = 0x27390000;
|
|
const unsigned JrT9Instr = 0x03200008, NopInstr = 0x0;
|
|
|
|
writeBytesUnaligned(LuiT9Instr, Addr, 4);
|
|
writeBytesUnaligned(AdduiT9Instr, Addr+4, 4);
|
|
writeBytesUnaligned(JrT9Instr, Addr+8, 4);
|
|
writeBytesUnaligned(NopInstr, Addr+12, 4);
|
|
return Addr;
|
|
} else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
|
|
// Depending on which version of the ELF ABI is in use, we need to
|
|
// generate one of two variants of the stub. They both start with
|
|
// the same sequence to load the target address into r12.
|
|
writeInt32BE(Addr, 0x3D800000); // lis r12, highest(addr)
|
|
writeInt32BE(Addr+4, 0x618C0000); // ori r12, higher(addr)
|
|
writeInt32BE(Addr+8, 0x798C07C6); // sldi r12, r12, 32
|
|
writeInt32BE(Addr+12, 0x658C0000); // oris r12, r12, h(addr)
|
|
writeInt32BE(Addr+16, 0x618C0000); // ori r12, r12, l(addr)
|
|
if (AbiVariant == 2) {
|
|
// PowerPC64 stub ELFv2 ABI: The address points to the function itself.
|
|
// The address is already in r12 as required by the ABI. Branch to it.
|
|
writeInt32BE(Addr+20, 0xF8410018); // std r2, 24(r1)
|
|
writeInt32BE(Addr+24, 0x7D8903A6); // mtctr r12
|
|
writeInt32BE(Addr+28, 0x4E800420); // bctr
|
|
} else {
|
|
// PowerPC64 stub ELFv1 ABI: The address points to a function descriptor.
|
|
// Load the function address on r11 and sets it to control register. Also
|
|
// loads the function TOC in r2 and environment pointer to r11.
|
|
writeInt32BE(Addr+20, 0xF8410028); // std r2, 40(r1)
|
|
writeInt32BE(Addr+24, 0xE96C0000); // ld r11, 0(r12)
|
|
writeInt32BE(Addr+28, 0xE84C0008); // ld r2, 0(r12)
|
|
writeInt32BE(Addr+32, 0x7D6903A6); // mtctr r11
|
|
writeInt32BE(Addr+36, 0xE96C0010); // ld r11, 16(r2)
|
|
writeInt32BE(Addr+40, 0x4E800420); // bctr
|
|
}
|
|
return Addr;
|
|
} else if (Arch == Triple::systemz) {
|
|
writeInt16BE(Addr, 0xC418); // lgrl %r1,.+8
|
|
writeInt16BE(Addr+2, 0x0000);
|
|
writeInt16BE(Addr+4, 0x0004);
|
|
writeInt16BE(Addr+6, 0x07F1); // brc 15,%r1
|
|
// 8-byte address stored at Addr + 8
|
|
return Addr;
|
|
} else if (Arch == Triple::x86_64) {
|
|
*Addr = 0xFF; // jmp
|
|
*(Addr+1) = 0x25; // rip
|
|
// 32-bit PC-relative address of the GOT entry will be stored at Addr+2
|
|
} else if (Arch == Triple::x86) {
|
|
*Addr = 0xE9; // 32-bit pc-relative jump.
|
|
}
|
|
return Addr;
|
|
}
|
|
|
|
// Assign an address to a symbol name and resolve all the relocations
|
|
// associated with it.
|
|
void RuntimeDyldImpl::reassignSectionAddress(unsigned SectionID,
|
|
uint64_t Addr) {
|
|
// The address to use for relocation resolution is not
|
|
// the address of the local section buffer. We must be doing
|
|
// a remote execution environment of some sort. Relocations can't
|
|
// be applied until all the sections have been moved. The client must
|
|
// trigger this with a call to MCJIT::finalize() or
|
|
// RuntimeDyld::resolveRelocations().
|
|
//
|
|
// Addr is a uint64_t because we can't assume the pointer width
|
|
// of the target is the same as that of the host. Just use a generic
|
|
// "big enough" type.
|
|
DEBUG(dbgs() << "Reassigning address for section "
|
|
<< SectionID << " (" << Sections[SectionID].Name << "): "
|
|
<< format("0x%016" PRIx64, Sections[SectionID].LoadAddress) << " -> "
|
|
<< format("0x%016" PRIx64, Addr) << "\n");
|
|
Sections[SectionID].LoadAddress = Addr;
|
|
}
|
|
|
|
void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs,
|
|
uint64_t Value) {
|
|
for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
|
|
const RelocationEntry &RE = Relocs[i];
|
|
// Ignore relocations for sections that were not loaded
|
|
if (Sections[RE.SectionID].Address == nullptr)
|
|
continue;
|
|
resolveRelocation(RE, Value);
|
|
}
|
|
}
|
|
|
|
void RuntimeDyldImpl::resolveExternalSymbols() {
|
|
while (!ExternalSymbolRelocations.empty()) {
|
|
StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin();
|
|
|
|
StringRef Name = i->first();
|
|
if (Name.size() == 0) {
|
|
// This is an absolute symbol, use an address of zero.
|
|
DEBUG(dbgs() << "Resolving absolute relocations."
|
|
<< "\n");
|
|
RelocationList &Relocs = i->second;
|
|
resolveRelocationList(Relocs, 0);
|
|
} else {
|
|
uint64_t Addr = 0;
|
|
RTDyldSymbolTable::const_iterator Loc = GlobalSymbolTable.find(Name);
|
|
if (Loc == GlobalSymbolTable.end()) {
|
|
// This is an external symbol, try to get its address from the symbol
|
|
// resolver.
|
|
Addr = Resolver.findSymbol(Name.data()).getAddress();
|
|
// The call to getSymbolAddress may have caused additional modules to
|
|
// be loaded, which may have added new entries to the
|
|
// ExternalSymbolRelocations map. Consquently, we need to update our
|
|
// iterator. This is also why retrieval of the relocation list
|
|
// associated with this symbol is deferred until below this point.
|
|
// New entries may have been added to the relocation list.
|
|
i = ExternalSymbolRelocations.find(Name);
|
|
} else {
|
|
// We found the symbol in our global table. It was probably in a
|
|
// Module that we loaded previously.
|
|
const auto &SymInfo = Loc->second;
|
|
Addr = getSectionLoadAddress(SymInfo.getSectionID()) +
|
|
SymInfo.getOffset();
|
|
}
|
|
|
|
// FIXME: Implement error handling that doesn't kill the host program!
|
|
if (!Addr)
|
|
report_fatal_error("Program used external function '" + Name +
|
|
"' which could not be resolved!");
|
|
|
|
// If Resolver returned UINT64_MAX, the client wants to handle this symbol
|
|
// manually and we shouldn't resolve its relocations.
|
|
if (Addr != UINT64_MAX) {
|
|
DEBUG(dbgs() << "Resolving relocations Name: " << Name << "\t"
|
|
<< format("0x%lx", Addr) << "\n");
|
|
// This list may have been updated when we called getSymbolAddress, so
|
|
// don't change this code to get the list earlier.
|
|
RelocationList &Relocs = i->second;
|
|
resolveRelocationList(Relocs, Addr);
|
|
}
|
|
}
|
|
|
|
ExternalSymbolRelocations.erase(i);
|
|
}
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// RuntimeDyld class implementation
|
|
|
|
uint64_t RuntimeDyld::LoadedObjectInfo::getSectionLoadAddress(
|
|
StringRef SectionName) const {
|
|
for (unsigned I = BeginIdx; I != EndIdx; ++I)
|
|
if (RTDyld.Sections[I].Name == SectionName)
|
|
return RTDyld.Sections[I].LoadAddress;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void RuntimeDyld::MemoryManager::anchor() {}
|
|
void RuntimeDyld::SymbolResolver::anchor() {}
|
|
|
|
RuntimeDyld::RuntimeDyld(RuntimeDyld::MemoryManager &MemMgr,
|
|
RuntimeDyld::SymbolResolver &Resolver)
|
|
: MemMgr(MemMgr), Resolver(Resolver) {
|
|
// FIXME: There's a potential issue lurking here if a single instance of
|
|
// RuntimeDyld is used to load multiple objects. The current implementation
|
|
// associates a single memory manager with a RuntimeDyld instance. Even
|
|
// though the public class spawns a new 'impl' instance for each load,
|
|
// they share a single memory manager. This can become a problem when page
|
|
// permissions are applied.
|
|
Dyld = nullptr;
|
|
ProcessAllSections = false;
|
|
Checker = nullptr;
|
|
}
|
|
|
|
RuntimeDyld::~RuntimeDyld() {}
|
|
|
|
static std::unique_ptr<RuntimeDyldCOFF>
|
|
createRuntimeDyldCOFF(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MM,
|
|
RuntimeDyld::SymbolResolver &Resolver,
|
|
bool ProcessAllSections, RuntimeDyldCheckerImpl *Checker) {
|
|
std::unique_ptr<RuntimeDyldCOFF> Dyld =
|
|
RuntimeDyldCOFF::create(Arch, MM, Resolver);
|
|
Dyld->setProcessAllSections(ProcessAllSections);
|
|
Dyld->setRuntimeDyldChecker(Checker);
|
|
return Dyld;
|
|
}
|
|
|
|
static std::unique_ptr<RuntimeDyldELF>
|
|
createRuntimeDyldELF(RuntimeDyld::MemoryManager &MM,
|
|
RuntimeDyld::SymbolResolver &Resolver,
|
|
bool ProcessAllSections, RuntimeDyldCheckerImpl *Checker) {
|
|
std::unique_ptr<RuntimeDyldELF> Dyld(new RuntimeDyldELF(MM, Resolver));
|
|
Dyld->setProcessAllSections(ProcessAllSections);
|
|
Dyld->setRuntimeDyldChecker(Checker);
|
|
return Dyld;
|
|
}
|
|
|
|
static std::unique_ptr<RuntimeDyldMachO>
|
|
createRuntimeDyldMachO(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MM,
|
|
RuntimeDyld::SymbolResolver &Resolver,
|
|
bool ProcessAllSections,
|
|
RuntimeDyldCheckerImpl *Checker) {
|
|
std::unique_ptr<RuntimeDyldMachO> Dyld =
|
|
RuntimeDyldMachO::create(Arch, MM, Resolver);
|
|
Dyld->setProcessAllSections(ProcessAllSections);
|
|
Dyld->setRuntimeDyldChecker(Checker);
|
|
return Dyld;
|
|
}
|
|
|
|
std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
|
|
RuntimeDyld::loadObject(const ObjectFile &Obj) {
|
|
if (!Dyld) {
|
|
if (Obj.isELF())
|
|
Dyld = createRuntimeDyldELF(MemMgr, Resolver, ProcessAllSections, Checker);
|
|
else if (Obj.isMachO())
|
|
Dyld = createRuntimeDyldMachO(
|
|
static_cast<Triple::ArchType>(Obj.getArch()), MemMgr, Resolver,
|
|
ProcessAllSections, Checker);
|
|
else if (Obj.isCOFF())
|
|
Dyld = createRuntimeDyldCOFF(
|
|
static_cast<Triple::ArchType>(Obj.getArch()), MemMgr, Resolver,
|
|
ProcessAllSections, Checker);
|
|
else
|
|
report_fatal_error("Incompatible object format!");
|
|
}
|
|
|
|
if (!Dyld->isCompatibleFile(Obj))
|
|
report_fatal_error("Incompatible object format!");
|
|
|
|
return Dyld->loadObject(Obj);
|
|
}
|
|
|
|
void *RuntimeDyld::getSymbolLocalAddress(StringRef Name) const {
|
|
if (!Dyld)
|
|
return nullptr;
|
|
return Dyld->getSymbolLocalAddress(Name);
|
|
}
|
|
|
|
RuntimeDyld::SymbolInfo RuntimeDyld::getSymbol(StringRef Name) const {
|
|
if (!Dyld)
|
|
return nullptr;
|
|
return Dyld->getSymbol(Name);
|
|
}
|
|
|
|
void RuntimeDyld::resolveRelocations() { Dyld->resolveRelocations(); }
|
|
|
|
void RuntimeDyld::reassignSectionAddress(unsigned SectionID, uint64_t Addr) {
|
|
Dyld->reassignSectionAddress(SectionID, Addr);
|
|
}
|
|
|
|
void RuntimeDyld::mapSectionAddress(const void *LocalAddress,
|
|
uint64_t TargetAddress) {
|
|
Dyld->mapSectionAddress(LocalAddress, TargetAddress);
|
|
}
|
|
|
|
bool RuntimeDyld::hasError() { return Dyld->hasError(); }
|
|
|
|
StringRef RuntimeDyld::getErrorString() { return Dyld->getErrorString(); }
|
|
|
|
void RuntimeDyld::registerEHFrames() {
|
|
if (Dyld)
|
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Dyld->registerEHFrames();
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}
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void RuntimeDyld::deregisterEHFrames() {
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if (Dyld)
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Dyld->deregisterEHFrames();
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}
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} // end namespace llvm
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