diff options
Diffstat (limited to 'contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp')
| -rw-r--r-- | contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp new file mode 100644 index 0000000..b464040 --- /dev/null +++ b/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp @@ -0,0 +1,483 @@ +//===-- RuntimeDyld.cpp - Run-time dynamic linker for MC-JIT ----*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Implementation of the MC-JIT runtime dynamic linker. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "dyld" +#include "RuntimeDyldImpl.h" +#include "RuntimeDyldELF.h" +#include "RuntimeDyldMachO.h" +#include "llvm/Support/Path.h" + +using namespace llvm; +using namespace llvm::object; + +// Empty out-of-line virtual destructor as the key function. +RTDyldMemoryManager::~RTDyldMemoryManager() {} +RuntimeDyldImpl::~RuntimeDyldImpl() {} + +namespace llvm { + +namespace { + // Helper for extensive error checking in debug builds. + error_code Check(error_code Err) { + if (Err) { + report_fatal_error(Err.message()); + } + return Err; + } +} // end anonymous namespace + +// Resolve the relocations for all symbols we currently know about. +void RuntimeDyldImpl::resolveRelocations() { + // First, resolve relocations associated with external symbols. + resolveExternalSymbols(); + + // Just iterate over the sections we have and resolve all the relocations + // in them. Gross overkill, but it gets the job done. + for (int i = 0, e = Sections.size(); i != e; ++i) { + reassignSectionAddress(i, Sections[i].LoadAddress); + } +} + +void RuntimeDyldImpl::mapSectionAddress(void *LocalAddress, + uint64_t TargetAddress) { + for (unsigned i = 0, e = Sections.size(); i != e; ++i) { + if (Sections[i].Address == LocalAddress) { + reassignSectionAddress(i, TargetAddress); + return; + } + } + llvm_unreachable("Attempting to remap address of unknown section!"); +} + +// Subclasses can implement this method to create specialized image instances. +// The caller owns the pointer that is returned. +ObjectImage *RuntimeDyldImpl::createObjectImage(const MemoryBuffer *InputBuffer) { + ObjectFile *ObjFile = ObjectFile::createObjectFile(const_cast<MemoryBuffer*> + (InputBuffer)); + ObjectImage *Obj = new ObjectImage(ObjFile); + return Obj; +} + +bool RuntimeDyldImpl::loadObject(const MemoryBuffer *InputBuffer) { + OwningPtr<ObjectImage> obj(createObjectImage(InputBuffer)); + if (!obj) + report_fatal_error("Unable to create object image from memory buffer!"); + + Arch = (Triple::ArchType)obj->getArch(); + + // Symbols found in this object + StringMap<SymbolLoc> LocalSymbols; + // Used sections from the object file + ObjSectionToIDMap LocalSections; + + // Common symbols requiring allocation, and the total size required to + // allocate all common symbols. + CommonSymbolMap CommonSymbols; + uint64_t CommonSize = 0; + + error_code err; + // Parse symbols + DEBUG(dbgs() << "Parse symbols:\n"); + for (symbol_iterator i = obj->begin_symbols(), e = obj->end_symbols(); + i != e; i.increment(err)) { + Check(err); + object::SymbolRef::Type SymType; + StringRef Name; + Check(i->getType(SymType)); + Check(i->getName(Name)); + + uint32_t flags; + Check(i->getFlags(flags)); + + bool isCommon = flags & SymbolRef::SF_Common; + if (isCommon) { + // Add the common symbols to a list. We'll allocate them all below. + uint64_t Size = 0; + Check(i->getSize(Size)); + CommonSize += Size; + CommonSymbols[*i] = Size; + } else { + if (SymType == object::SymbolRef::ST_Function || + SymType == object::SymbolRef::ST_Data) { + uint64_t FileOffset; + StringRef SectionData; + section_iterator si = obj->end_sections(); + Check(i->getFileOffset(FileOffset)); + Check(i->getSection(si)); + if (si == obj->end_sections()) continue; + Check(si->getContents(SectionData)); + const uint8_t* SymPtr = (const uint8_t*)InputBuffer->getBufferStart() + + (uintptr_t)FileOffset; + uintptr_t SectOffset = (uintptr_t)(SymPtr - + (const uint8_t*)SectionData.begin()); + unsigned SectionID = + findOrEmitSection(*obj, + *si, + SymType == object::SymbolRef::ST_Function, + LocalSections); + LocalSymbols[Name.data()] = SymbolLoc(SectionID, SectOffset); + DEBUG(dbgs() << "\tFileOffset: " << format("%p", (uintptr_t)FileOffset) + << " flags: " << flags + << " SID: " << SectionID + << " Offset: " << format("%p", SectOffset)); + bool isGlobal = flags & SymbolRef::SF_Global; + if (isGlobal) + GlobalSymbolTable[Name] = SymbolLoc(SectionID, SectOffset); + } + } + DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name << "\n"); + } + + // Allocate common symbols + if (CommonSize != 0) + emitCommonSymbols(*obj, CommonSymbols, CommonSize, LocalSymbols); + + // Parse and process relocations + DEBUG(dbgs() << "Parse relocations:\n"); + for (section_iterator si = obj->begin_sections(), + se = obj->end_sections(); si != se; si.increment(err)) { + Check(err); + bool isFirstRelocation = true; + unsigned SectionID = 0; + StubMap Stubs; + + for (relocation_iterator i = si->begin_relocations(), + e = si->end_relocations(); i != e; i.increment(err)) { + Check(err); + + // If it's the first relocation in this section, find its SectionID + if (isFirstRelocation) { + SectionID = findOrEmitSection(*obj, *si, true, LocalSections); + DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n"); + isFirstRelocation = false; + } + + ObjRelocationInfo RI; + RI.SectionID = SectionID; + Check(i->getAdditionalInfo(RI.AdditionalInfo)); + Check(i->getOffset(RI.Offset)); + Check(i->getSymbol(RI.Symbol)); + Check(i->getType(RI.Type)); + + DEBUG(dbgs() << "\t\tAddend: " << RI.AdditionalInfo + << " Offset: " << format("%p", (uintptr_t)RI.Offset) + << " Type: " << (uint32_t)(RI.Type & 0xffffffffL) + << "\n"); + processRelocationRef(RI, *obj, LocalSections, LocalSymbols, Stubs); + } + } + + handleObjectLoaded(obj.take()); + + return false; +} + +void RuntimeDyldImpl::emitCommonSymbols(ObjectImage &Obj, + const CommonSymbolMap &CommonSymbols, + uint64_t TotalSize, + SymbolTableMap &SymbolTable) { + // Allocate memory for the section + unsigned SectionID = Sections.size(); + uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, sizeof(void*), + SectionID); + if (!Addr) + report_fatal_error("Unable to allocate memory for common symbols!"); + uint64_t Offset = 0; + Sections.push_back(SectionEntry(Addr, TotalSize, TotalSize, 0)); + memset(Addr, 0, TotalSize); + + DEBUG(dbgs() << "emitCommonSection SectionID: " << SectionID + << " new addr: " << format("%p", Addr) + << " DataSize: " << TotalSize + << "\n"); + + // Assign the address of each symbol + for (CommonSymbolMap::const_iterator it = CommonSymbols.begin(), + itEnd = CommonSymbols.end(); it != itEnd; it++) { + StringRef Name; + it->first.getName(Name); + Obj.updateSymbolAddress(it->first, (uint64_t)Addr); + SymbolTable[Name.data()] = SymbolLoc(SectionID, Offset); + uint64_t Size = it->second; + Offset += Size; + Addr += Size; + } +} + +unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj, + const SectionRef &Section, + bool IsCode) { + + unsigned StubBufSize = 0, + StubSize = getMaxStubSize(); + error_code err; + if (StubSize > 0) { + for (relocation_iterator i = Section.begin_relocations(), + e = Section.end_relocations(); i != e; i.increment(err), Check(err)) + StubBufSize += StubSize; + } + StringRef data; + uint64_t Alignment64; + Check(Section.getContents(data)); + Check(Section.getAlignment(Alignment64)); + + unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL; + bool IsRequired; + bool IsVirtual; + bool IsZeroInit; + uint64_t DataSize; + Check(Section.isRequiredForExecution(IsRequired)); + Check(Section.isVirtual(IsVirtual)); + Check(Section.isZeroInit(IsZeroInit)); + Check(Section.getSize(DataSize)); + + unsigned Allocate; + unsigned SectionID = Sections.size(); + uint8_t *Addr; + const char *pData = 0; + + // Some sections, such as debug info, don't need to be loaded for execution. + // Leave those where they are. + if (IsRequired) { + Allocate = DataSize + StubBufSize; + Addr = IsCode + ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID) + : MemMgr->allocateDataSection(Allocate, Alignment, SectionID); + if (!Addr) + report_fatal_error("Unable to allocate section memory!"); + + // Virtual sections have no data in the object image, so leave pData = 0 + if (!IsVirtual) + pData = data.data(); + + // Zero-initialize or copy the data from the image + if (IsZeroInit || IsVirtual) + memset(Addr, 0, DataSize); + else + memcpy(Addr, pData, DataSize); + + DEBUG(dbgs() << "emitSection SectionID: " << SectionID + << " obj addr: " << format("%p", pData) + << " new addr: " << format("%p", Addr) + << " DataSize: " << DataSize + << " StubBufSize: " << StubBufSize + << " Allocate: " << Allocate + << "\n"); + Obj.updateSectionAddress(Section, (uint64_t)Addr); + } + 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 = 0; + DEBUG(dbgs() << "emitSection SectionID: " << SectionID + << " obj addr: " << format("%p", data.data()) + << " new addr: 0" + << " DataSize: " << DataSize + << " StubBufSize: " << StubBufSize + << " Allocate: " << Allocate + << "\n"); + } + + Sections.push_back(SectionEntry(Addr, Allocate, DataSize,(uintptr_t)pData)); + return SectionID; +} + +unsigned RuntimeDyldImpl::findOrEmitSection(ObjectImage &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. + SymbolTableMap::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; + RECopy.Addend += Loc->second.second; + Relocations[Loc->second.first].push_back(RECopy); + } +} + +uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr) { + // TODO: There is only ARM far stub now. We should add the Thumb stub, + // and stubs for branches Thumb - ARM and ARM - Thumb. + if (Arch == Triple::arm) { + uint32_t *StubAddr = (uint32_t*)Addr; + *StubAddr = 0xe51ff004; // ldr pc,<label> + return (uint8_t*)++StubAddr; + } + else + 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. Re-apply any + // relocations referencing this section with the given address. + // + // 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. + Sections[SectionID].LoadAddress = Addr; + DEBUG(dbgs() << "Resolving relocations Section #" << SectionID + << "\t" << format("%p", (uint8_t *)Addr) + << "\n"); + resolveRelocationList(Relocations[SectionID], Addr); +} + +void RuntimeDyldImpl::resolveRelocationEntry(const RelocationEntry &RE, + uint64_t Value) { + // Ignore relocations for sections that were not loaded + if (Sections[RE.SectionID].Address != 0) { + uint8_t *Target = Sections[RE.SectionID].Address + RE.Offset; + DEBUG(dbgs() << "\tSectionID: " << RE.SectionID + << " + " << RE.Offset << " (" << format("%p", Target) << ")" + << " RelType: " << RE.RelType + << " Addend: " << RE.Addend + << "\n"); + + resolveRelocation(Target, Sections[RE.SectionID].LoadAddress + RE.Offset, + Value, RE.RelType, RE.Addend); + } +} + +void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs, + uint64_t Value) { + for (unsigned i = 0, e = Relocs.size(); i != e; ++i) { + resolveRelocationEntry(Relocs[i], Value); + } +} + +void RuntimeDyldImpl::resolveExternalSymbols() { + StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin(), + e = ExternalSymbolRelocations.end(); + for (; i != e; i++) { + StringRef Name = i->first(); + RelocationList &Relocs = i->second; + SymbolTableMap::const_iterator Loc = GlobalSymbolTable.find(Name); + if (Loc == GlobalSymbolTable.end()) { + // This is an external symbol, try to get it address from + // MemoryManager. + uint8_t *Addr = (uint8_t*) MemMgr->getPointerToNamedFunction(Name.data(), + true); + DEBUG(dbgs() << "Resolving relocations Name: " << Name + << "\t" << format("%p", Addr) + << "\n"); + resolveRelocationList(Relocs, (uintptr_t)Addr); + } else { + report_fatal_error("Expected external symbol"); + } + } +} + + +//===----------------------------------------------------------------------===// +// RuntimeDyld class implementation +RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) { + Dyld = 0; + MM = mm; +} + +RuntimeDyld::~RuntimeDyld() { + delete Dyld; +} + +bool RuntimeDyld::loadObject(MemoryBuffer *InputBuffer) { + if (!Dyld) { + sys::LLVMFileType type = sys::IdentifyFileType( + InputBuffer->getBufferStart(), + static_cast<unsigned>(InputBuffer->getBufferSize())); + switch (type) { + case sys::ELF_Relocatable_FileType: + case sys::ELF_Executable_FileType: + case sys::ELF_SharedObject_FileType: + case sys::ELF_Core_FileType: + Dyld = new RuntimeDyldELF(MM); + break; + case sys::Mach_O_Object_FileType: + case sys::Mach_O_Executable_FileType: + case sys::Mach_O_FixedVirtualMemorySharedLib_FileType: + case sys::Mach_O_Core_FileType: + case sys::Mach_O_PreloadExecutable_FileType: + case sys::Mach_O_DynamicallyLinkedSharedLib_FileType: + case sys::Mach_O_DynamicLinker_FileType: + case sys::Mach_O_Bundle_FileType: + case sys::Mach_O_DynamicallyLinkedSharedLibStub_FileType: + case sys::Mach_O_DSYMCompanion_FileType: + Dyld = new RuntimeDyldMachO(MM); + break; + case sys::Unknown_FileType: + case sys::Bitcode_FileType: + case sys::Archive_FileType: + case sys::COFF_FileType: + report_fatal_error("Incompatible object format!"); + } + } else { + if (!Dyld->isCompatibleFormat(InputBuffer)) + report_fatal_error("Incompatible object format!"); + } + + return Dyld->loadObject(InputBuffer); +} + +void *RuntimeDyld::getSymbolAddress(StringRef Name) { + return Dyld->getSymbolAddress(Name); +} + +void RuntimeDyld::resolveRelocations() { + Dyld->resolveRelocations(); +} + +void RuntimeDyld::reassignSectionAddress(unsigned SectionID, + uint64_t Addr) { + Dyld->reassignSectionAddress(SectionID, Addr); +} + +void RuntimeDyld::mapSectionAddress(void *LocalAddress, + uint64_t TargetAddress) { + Dyld->mapSectionAddress(LocalAddress, TargetAddress); +} + +StringRef RuntimeDyld::getErrorString() { + return Dyld->getErrorString(); +} + +} // end namespace llvm |
