| //===-- RuntimeDyldImpl.h - 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. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Interface for the implementations of runtime dynamic linker facilities. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_RUNTIME_DYLD_IMPL_H |
| #define LLVM_RUNTIME_DYLD_IMPL_H |
| |
| #include "llvm/ExecutionEngine/RuntimeDyld.h" |
| #include "llvm/Object/ObjectFile.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/StringMap.h" |
| #include "llvm/ADT/Twine.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/Support/Memory.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/system_error.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/ADT/Triple.h" |
| #include <map> |
| #include "llvm/Support/Format.h" |
| #include "ObjectImage.h" |
| |
| using namespace llvm; |
| using namespace llvm::object; |
| |
| namespace llvm { |
| |
| class SectionEntry { |
| public: |
| uint8_t* Address; |
| size_t Size; |
| uint64_t LoadAddress; // For each section, the address it will be |
| // considered to live at for relocations. The same |
| // as the pointer to the above memory block for |
| // hosted JITs. |
| uintptr_t StubOffset; // It's used for architecturies with stub |
| // functions for far relocations like ARM. |
| uintptr_t ObjAddress; // Section address in object file. It's use for |
| // calculate MachO relocation addend |
| SectionEntry(uint8_t* address, size_t size, uintptr_t stubOffset, |
| uintptr_t objAddress) |
| : Address(address), Size(size), LoadAddress((uintptr_t)address), |
| StubOffset(stubOffset), ObjAddress(objAddress) {} |
| }; |
| |
| class RelocationEntry { |
| public: |
| unsigned SectionID; // Section the relocation is contained in. |
| uintptr_t Offset; // Offset into the section for the relocation. |
| uint32_t Data; // Relocatino data. Including type of relocation |
| // and another flags and parameners from |
| intptr_t Addend; // Addend encoded in the instruction itself, if any, |
| // plus the offset into the source section for |
| // the symbol once the relocation is resolvable. |
| RelocationEntry(unsigned id, uint64_t offset, uint32_t data, int64_t addend) |
| : SectionID(id), Offset(offset), Data(data), Addend(addend) {} |
| }; |
| |
| // Raw relocation data from object file |
| class ObjRelocationInfo { |
| public: |
| unsigned SectionID; |
| uint64_t Offset; |
| SymbolRef Symbol; |
| uint64_t Type; |
| int64_t AdditionalInfo; |
| }; |
| |
| class RelocationValueRef { |
| public: |
| unsigned SectionID; |
| intptr_t Addend; |
| const char *SymbolName; |
| RelocationValueRef(): SectionID(0), Addend(0), SymbolName(0) {} |
| |
| inline bool operator==(const RelocationValueRef &Other) const { |
| return std::memcmp(this, &Other, sizeof(RelocationValueRef)) == 0; |
| } |
| inline bool operator <(const RelocationValueRef &Other) const { |
| return std::memcmp(this, &Other, sizeof(RelocationValueRef)) < 0; |
| } |
| }; |
| |
| class RuntimeDyldImpl { |
| protected: |
| // The MemoryManager to load objects into. |
| RTDyldMemoryManager *MemMgr; |
| |
| // A list of emmitted sections. |
| typedef SmallVector<SectionEntry, 64> SectionList; |
| SectionList Sections; |
| |
| // Keep a map of sections from object file to the SectionID which |
| // references it. |
| typedef std::map<SectionRef, unsigned> ObjSectionToIDMap; |
| |
| // Master symbol table. As modules are loaded and external symbols are |
| // resolved, their addresses are stored here as a SectionID/Offset pair. |
| typedef std::pair<unsigned, uintptr_t> SymbolLoc; |
| StringMap<SymbolLoc> SymbolTable; |
| typedef DenseMap<const char*, SymbolLoc> LocalSymbolMap; |
| |
| // Keep a map of common symbols to their sizes |
| typedef std::map<SymbolRef, unsigned> CommonSymbolMap; |
| |
| // For each symbol, keep a list of relocations based on it. Anytime |
| // its address is reassigned (the JIT re-compiled the function, e.g.), |
| // the relocations get re-resolved. |
| // The symbol (or section) the relocation is sourced from is the Key |
| // in the relocation list where it's stored. |
| typedef SmallVector<RelocationEntry, 64> RelocationList; |
| // Relocations to sections already loaded. Indexed by SectionID which is the |
| // source of the address. The target where the address will be writen is |
| // SectionID/Offset in the relocation itself. |
| DenseMap<unsigned, RelocationList> Relocations; |
| // Relocations to external symbols that are not yet resolved. |
| // Indexed by symbol name. |
| StringMap<RelocationList> SymbolRelocations; |
| |
| typedef std::map<RelocationValueRef, uintptr_t> StubMap; |
| |
| Triple::ArchType Arch; |
| |
| inline unsigned getMaxStubSize() { |
| if (Arch == Triple::arm || Arch == Triple::thumb) |
| return 8; // 32-bit instruction and 32-bit address |
| else |
| return 0; |
| } |
| |
| bool HasError; |
| std::string ErrorStr; |
| |
| // Set the error state and record an error string. |
| bool Error(const Twine &Msg) { |
| ErrorStr = Msg.str(); |
| HasError = true; |
| return true; |
| } |
| |
| uint8_t *getSectionAddress(unsigned SectionID) { |
| return (uint8_t*)Sections[SectionID].Address; |
| } |
| |
| /// \brief Emits a section containing common symbols. |
| /// \return SectionID. |
| unsigned emitCommonSymbols(ObjectImage &Obj, |
| const CommonSymbolMap &Map, |
| uint64_t TotalSize, |
| LocalSymbolMap &Symbols); |
| |
| /// \brief Emits section data from the object file to the MemoryManager. |
| /// \param IsCode if it's true then allocateCodeSection() will be |
| /// used for emmits, else allocateDataSection() will be used. |
| /// \return SectionID. |
| unsigned emitSection(ObjectImage &Obj, |
| const SectionRef &Section, |
| bool IsCode); |
| |
| /// \brief Find Section in LocalSections. If the secton is not found - emit |
| /// it and store in LocalSections. |
| /// \param IsCode if it's true then allocateCodeSection() will be |
| /// used for emmits, else allocateDataSection() will be used. |
| /// \return SectionID. |
| unsigned findOrEmitSection(ObjectImage &Obj, |
| const SectionRef &Section, |
| bool IsCode, |
| ObjSectionToIDMap &LocalSections); |
| |
| /// \brief If Value.SymbolName is NULL then store relocation to the |
| /// Relocations, else store it in the SymbolRelocations. |
| void AddRelocation(const RelocationValueRef &Value, unsigned SectionID, |
| uintptr_t Offset, uint32_t RelType); |
| |
| /// \brief Emits long jump instruction to Addr. |
| /// \return Pointer to the memory area for emitting target address. |
| uint8_t* createStubFunction(uint8_t *Addr); |
| |
| /// \brief Resolves relocations from Relocs list with address from Value. |
| void resolveRelocationList(const RelocationList &Relocs, uint64_t Value); |
| void resolveRelocationEntry(const RelocationEntry &RE, uint64_t Value); |
| |
| /// \brief A object file specific relocation resolver |
| /// \param Address Address to apply the relocation action |
| /// \param Value Target symbol address to apply the relocation action |
| /// \param Type object file specific relocation type |
| /// \param Addend A constant addend used to compute the value to be stored |
| /// into the relocatable field |
| virtual void resolveRelocation(uint8_t *LocalAddress, |
| uint64_t FinalAddress, |
| uint64_t Value, |
| uint32_t Type, |
| int64_t Addend) = 0; |
| |
| /// \brief Parses the object file relocation and store it to Relocations |
| /// or SymbolRelocations. Its depend from object file type. |
| virtual void processRelocationRef(const ObjRelocationInfo &Rel, |
| ObjectImage &Obj, |
| ObjSectionToIDMap &ObjSectionToID, |
| LocalSymbolMap &Symbols, StubMap &Stubs) = 0; |
| |
| void resolveSymbols(); |
| virtual ObjectImage *createObjectImage(const MemoryBuffer *InputBuffer); |
| virtual void handleObjectLoaded(ObjectImage *Obj) |
| { |
| // Subclasses may choose to retain this image if they have a use for it |
| delete Obj; |
| } |
| |
| public: |
| RuntimeDyldImpl(RTDyldMemoryManager *mm) : MemMgr(mm), HasError(false) {} |
| |
| virtual ~RuntimeDyldImpl(); |
| |
| bool loadObject(const MemoryBuffer *InputBuffer); |
| |
| void *getSymbolAddress(StringRef Name) { |
| // FIXME: Just look up as a function for now. Overly simple of course. |
| // Work in progress. |
| if (SymbolTable.find(Name) == SymbolTable.end()) |
| return 0; |
| SymbolLoc Loc = SymbolTable.lookup(Name); |
| return getSectionAddress(Loc.first) + Loc.second; |
| } |
| |
| void resolveRelocations(); |
| |
| void reassignSectionAddress(unsigned SectionID, uint64_t Addr); |
| |
| void mapSectionAddress(void *LocalAddress, uint64_t TargetAddress); |
| |
| // Is the linker in an error state? |
| bool hasError() { return HasError; } |
| |
| // Mark the error condition as handled and continue. |
| void clearError() { HasError = false; } |
| |
| // Get the error message. |
| StringRef getErrorString() { return ErrorStr; } |
| |
| virtual bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const = 0; |
| |
| }; |
| |
| } // end namespace llvm |
| |
| |
| #endif |