#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/ADT/StringMap.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/ExecutionEngine/ObjectImage.h"
+#include "llvm/ExecutionEngine/RuntimeDyld.h"
+#include "llvm/Object/ObjectFile.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"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/Mutex.h"
+#include "llvm/Support/SwapByteOrder.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/system_error.h"
+#include <map>
using namespace llvm;
using namespace llvm::object;
namespace llvm {
+class ObjectBuffer;
+class Twine;
+
+/// SectionEntry - represents a section emitted into memory by the dynamic
+/// linker.
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 architectures with stub
- // functions for far relocations like ARM.
- uintptr_t ObjAddress; // Section address in object file. It's used for
- // calculating the MachO relocation addend.
- SectionEntry(uint8_t *address, size_t size, uintptr_t stubOffset,
+ /// Name - section name.
+ StringRef Name;
+
+ /// Address - address in the linker's memory where the section resides.
+ uint8_t *Address;
+
+ /// Size - section size. Doesn't include the stubs.
+ size_t Size;
+
+ /// LoadAddress - the address of the section in the target process's memory.
+ /// Used for situations in which JIT-ed code is being executed in the address
+ /// space of a separate process. If the code executes in the same address
+ /// space where it was JIT-ed, this just equals Address.
+ uint64_t LoadAddress;
+
+ /// StubOffset - used for architectures with stub functions for far
+ /// relocations (like ARM).
+ uintptr_t StubOffset;
+
+ /// ObjAddress - address of the section in the in-memory object file. Used
+ /// for calculating relocations in some object formats (like MachO).
+ uintptr_t ObjAddress;
+
+ SectionEntry(StringRef name, uint8_t *address, size_t size,
uintptr_t objAddress)
- : Address(address), Size(size), LoadAddress((uintptr_t)address),
- StubOffset(stubOffset), ObjAddress(objAddress) {}
+ : Name(name), Address(address), Size(size),
+ LoadAddress((uintptr_t)address), StubOffset(size),
+ ObjAddress(objAddress) {}
};
+/// RelocationEntry - used to represent relocations internally in the dynamic
+/// linker.
class RelocationEntry {
public:
- unsigned SectionID; // Section the relocation is contained in.
- uintptr_t Offset; // Offset into the section for the relocation.
- uint32_t Data; // Relocation data. Including type of relocation
- // and other flags.
- 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) {}
-};
+ /// SectionID - the section this relocation points to.
+ unsigned SectionID;
-// Raw relocation data from object file
-class ObjRelocationInfo {
-public:
- unsigned SectionID;
- uint64_t Offset;
- SymbolRef Symbol;
- uint64_t Type;
- int64_t AdditionalInfo;
+ /// Offset - offset into the section.
+ uint64_t Offset;
+
+ /// RelType - relocation type.
+ uint32_t RelType;
+
+ /// Addend - the relocation addend encoded in the instruction itself. Also
+ /// used to make a relocation section relative instead of symbol relative.
+ int64_t Addend;
+
+ /// SymOffset - Section offset of the relocation entry's symbol (used for GOT
+ /// lookup).
+ uint64_t SymOffset;
+
+ /// True if this is a PCRel relocation (MachO specific).
+ bool IsPCRel;
+
+ /// The size of this relocation (MachO specific).
+ unsigned Size;
+
+ RelocationEntry(unsigned id, uint64_t offset, uint32_t type, int64_t addend)
+ : SectionID(id), Offset(offset), RelType(type), Addend(addend),
+ SymOffset(0), IsPCRel(false), Size(0) {}
+
+ RelocationEntry(unsigned id, uint64_t offset, uint32_t type, int64_t addend,
+ uint64_t symoffset)
+ : SectionID(id), Offset(offset), RelType(type), Addend(addend),
+ SymOffset(symoffset), IsPCRel(false), Size(0) {}
+
+ RelocationEntry(unsigned id, uint64_t offset, uint32_t type, int64_t addend,
+ bool IsPCRel, unsigned Size)
+ : SectionID(id), Offset(offset), RelType(type), Addend(addend),
+ SymOffset(0), IsPCRel(IsPCRel), Size(Size) {}
};
class RelocationValueRef {
public:
- unsigned SectionID;
- intptr_t Addend;
+ unsigned SectionID;
+ uint64_t Offset;
+ int64_t Addend;
const char *SymbolName;
- RelocationValueRef(): SectionID(0), Addend(0), SymbolName(0) {}
+ RelocationValueRef() : SectionID(0), Offset(0), Addend(0),
+ SymbolName(nullptr) {}
inline bool operator==(const RelocationValueRef &Other) const {
- return std::memcmp(this, &Other, sizeof(RelocationValueRef)) == 0;
+ return SectionID == Other.SectionID && Offset == Other.Offset &&
+ Addend == Other.Addend && SymbolName == Other.SymbolName;
}
- inline bool operator <(const RelocationValueRef &Other) const {
- return std::memcmp(this, &Other, sizeof(RelocationValueRef)) < 0;
+ inline bool operator<(const RelocationValueRef &Other) const {
+ if (SectionID != Other.SectionID)
+ return SectionID < Other.SectionID;
+ if (Offset != Other.Offset)
+ return Offset < Other.Offset;
+ if (Addend != Other.Addend)
+ return Addend < Other.Addend;
+ return SymbolName < Other.SymbolName;
}
};
// The MemoryManager to load objects into.
RTDyldMemoryManager *MemMgr;
- // A list of emmitted sections.
+ // A list of all sections emitted by the dynamic linker. These sections are
+ // referenced in the code by means of their index in this list - SectionID.
typedef SmallVector<SectionEntry, 64> SectionList;
SectionList Sections;
+ typedef unsigned SID; // Type for SectionIDs
+#define RTDYLD_INVALID_SECTION_ID ((SID)(-1))
+
// 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.
+ // A global symbol table for symbols from all loaded modules. Maps the
+ // symbol name to a (SectionID, offset in section) pair.
typedef std::pair<unsigned, uintptr_t> SymbolLoc;
- StringMap<SymbolLoc> SymbolTable;
- typedef DenseMap<const char*, SymbolLoc> LocalSymbolMap;
+ typedef StringMap<SymbolLoc> SymbolTableMap;
+ SymbolTableMap GlobalSymbolTable;
- // Keep a map of common symbols to their sizes
- typedef std::map<SymbolRef, unsigned> CommonSymbolMap;
+ // Pair representing the size and alignment requirement for a common symbol.
+ typedef std::pair<unsigned, unsigned> CommonSymbolInfo;
+ // Keep a map of common symbols to their info pairs
+ typedef std::map<SymbolRef, CommonSymbolInfo> 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.),
// 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
+ // source of the address. The target where the address will be written 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;
+
+ // Relocations to external symbols that are not yet resolved. Symbols are
+ // external when they aren't found in the global symbol table of all loaded
+ // modules. This map is indexed by symbol name.
+ StringMap<RelocationList> ExternalSymbolRelocations;
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 IsTargetLittleEndian;
+
+ // True if all sections should be passed to the memory manager, false if only
+ // sections containing relocations should be. Defaults to 'false'.
+ bool ProcessAllSections;
+
+ // This mutex prevents simultaneously loading objects from two different
+ // threads. This keeps us from having to protect individual data structures
+ // and guarantees that section allocation requests to the memory manager
+ // won't be interleaved between modules. It is also used in mapSectionAddress
+ // and resolveRelocations to protect write access to internal data structures.
+ //
+ // loadObject may be called on the same thread during the handling of of
+ // processRelocations, and that's OK. The handling of the relocation lists
+ // is written in such a way as to work correctly if new elements are added to
+ // the end of the list while the list is being processed.
+ sys::Mutex lock;
+
+ virtual unsigned getMaxStubSize() = 0;
+ virtual unsigned getStubAlignment() = 0;
bool HasError;
std::string ErrorStr;
return true;
}
+ uint64_t getSectionLoadAddress(unsigned SectionID) {
+ return Sections[SectionID].LoadAddress;
+ }
+
uint8_t *getSectionAddress(unsigned SectionID) {
- return (uint8_t*)Sections[SectionID].Address;
+ 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);
+ void writeInt16BE(uint8_t *Addr, uint16_t Value) {
+ if (IsTargetLittleEndian)
+ Value = sys::SwapByteOrder(Value);
+ *Addr = (Value >> 8) & 0xFF;
+ *(Addr + 1) = Value & 0xFF;
+ }
+
+ void writeInt32BE(uint8_t *Addr, uint32_t Value) {
+ if (IsTargetLittleEndian)
+ Value = sys::SwapByteOrder(Value);
+ *Addr = (Value >> 24) & 0xFF;
+ *(Addr + 1) = (Value >> 16) & 0xFF;
+ *(Addr + 2) = (Value >> 8) & 0xFF;
+ *(Addr + 3) = Value & 0xFF;
+ }
+
+ void writeInt64BE(uint8_t *Addr, uint64_t Value) {
+ if (IsTargetLittleEndian)
+ Value = sys::SwapByteOrder(Value);
+ *Addr = (Value >> 56) & 0xFF;
+ *(Addr + 1) = (Value >> 48) & 0xFF;
+ *(Addr + 2) = (Value >> 40) & 0xFF;
+ *(Addr + 3) = (Value >> 32) & 0xFF;
+ *(Addr + 4) = (Value >> 24) & 0xFF;
+ *(Addr + 5) = (Value >> 16) & 0xFF;
+ *(Addr + 6) = (Value >> 8) & 0xFF;
+ *(Addr + 7) = Value & 0xFF;
+ }
+
+ /// \brief Given the common symbols discovered in the object file, emit a
+ /// new section for them and update the symbol mappings in the object and
+ /// symbol table.
+ void emitCommonSymbols(ObjectImage &Obj, const CommonSymbolMap &CommonSymbols,
+ uint64_t TotalSize, SymbolTableMap &SymbolTable);
/// \brief Emits section data from the object file to the MemoryManager.
/// \param IsCode if it's true then allocateCodeSection() will be
/// used for emits, else allocateDataSection() will be used.
/// \return SectionID.
- unsigned emitSection(ObjectImage &Obj,
- const SectionRef &Section,
+ unsigned emitSection(ObjectImage &Obj, const SectionRef &Section,
bool IsCode);
/// \brief Find Section in LocalSections. If the secton is not found - emit
/// \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);
+ unsigned findOrEmitSection(ObjectImage &Obj, const SectionRef &Section,
+ bool IsCode, ObjSectionToIDMap &LocalSections);
+
+ // \brief Add a relocation entry that uses the given section.
+ void addRelocationForSection(const RelocationEntry &RE, unsigned SectionID);
- /// \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 Add a relocation entry that uses the given symbol. This symbol may
+ // be found in the global symbol table, or it may be external.
+ void addRelocationForSymbol(const RelocationEntry &RE, StringRef SymbolName);
/// \brief Emits long jump instruction to Addr.
/// \return Pointer to the memory area for emitting target address.
- uint8_t* createStubFunction(uint8_t *Addr);
+ 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 RE The relocation to be resolved
/// \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 stores it to Relocations
- /// or SymbolRelocations (this depends on the 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;
- }
+ virtual void resolveRelocation(const RelocationEntry &RE, uint64_t Value) = 0;
+
+ /// \brief Parses one or more object file relocations (some object files use
+ /// relocation pairs) and stores it to Relocations or SymbolRelocations
+ /// (this depends on the object file type).
+ /// \return Iterator to the next relocation that needs to be parsed.
+ virtual relocation_iterator
+ processRelocationRef(unsigned SectionID, relocation_iterator RelI,
+ ObjectImage &Obj, ObjSectionToIDMap &ObjSectionToID,
+ const SymbolTableMap &Symbols, StubMap &Stubs) = 0;
+
+ /// \brief Resolve relocations to external symbols.
+ void resolveExternalSymbols();
+
+ /// \brief Update GOT entries for external symbols.
+ // The base class does nothing. ELF overrides this.
+ virtual void updateGOTEntries(StringRef Name, uint64_t Addr) {}
+
+ // \brief Compute an upper bound of the memory that is required to load all
+ // sections
+ void computeTotalAllocSize(ObjectImage &Obj, uint64_t &CodeSize,
+ uint64_t &DataSizeRO, uint64_t &DataSizeRW);
+
+ // \brief Compute the stub buffer size required for a section
+ unsigned computeSectionStubBufSize(ObjectImage &Obj,
+ const SectionRef &Section);
public:
- RuntimeDyldImpl(RTDyldMemoryManager *mm) : MemMgr(mm), HasError(false) {}
+ RuntimeDyldImpl(RTDyldMemoryManager *mm)
+ : MemMgr(mm), ProcessAllSections(false), HasError(false) {}
virtual ~RuntimeDyldImpl();
- bool loadObject(const MemoryBuffer *InputBuffer);
+ void setProcessAllSections(bool ProcessAllSections) {
+ this->ProcessAllSections = ProcessAllSections;
+ }
+
+ ObjectImage *loadObject(ObjectImage *InputObject);
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);
+ SymbolTableMap::const_iterator pos = GlobalSymbolTable.find(Name);
+ if (pos == GlobalSymbolTable.end())
+ return nullptr;
+ SymbolLoc Loc = pos->second;
return getSectionAddress(Loc.first) + Loc.second;
}
+ uint64_t getSymbolLoadAddress(StringRef Name) {
+ // FIXME: Just look up as a function for now. Overly simple of course.
+ // Work in progress.
+ SymbolTableMap::const_iterator pos = GlobalSymbolTable.find(Name);
+ if (pos == GlobalSymbolTable.end())
+ return 0;
+ SymbolLoc Loc = pos->second;
+ return getSectionLoadAddress(Loc.first) + Loc.second;
+ }
+
void resolveRelocations();
void reassignSectionAddress(unsigned SectionID, uint64_t Addr);
- void mapSectionAddress(void *LocalAddress, uint64_t TargetAddress);
+ void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress);
// Is the linker in an error state?
bool hasError() { return HasError; }
// Get the error message.
StringRef getErrorString() { return ErrorStr; }
- virtual bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const = 0;
+ virtual bool isCompatibleFormat(const ObjectBuffer *Buffer) const = 0;
+ virtual bool isCompatibleFile(const ObjectFile *Obj) const = 0;
+ virtual void registerEHFrames();
+
+ virtual void deregisterEHFrames();
+
+ virtual void finalizeLoad(ObjSectionToIDMap &SectionMap) {}
};
} // end namespace llvm
-
#endif