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//===-- 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/MachOObject.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Twine.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/Support/Format.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"
using namespace llvm;
using namespace llvm::object;
namespace llvm {
class RuntimeDyldImpl {
protected:
unsigned CPUType;
unsigned CPUSubtype;
// The MemoryManager to load objects into.
RTDyldMemoryManager *MemMgr;
// FIXME: This all assumes we're dealing with external symbols for anything
// explicitly referenced. I.e., we can index by name and things
// will work out. In practice, this may not be the case, so we
// should find a way to effectively generalize.
// For each function, we have a MemoryBlock of it's instruction data.
StringMap<sys::MemoryBlock> Functions;
// Master symbol table. As modules are loaded and external symbols are
// resolved, their addresses are stored here.
StringMap<uint8_t*> SymbolTable;
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;
}
void extractFunction(StringRef Name, uint8_t *StartAddress,
uint8_t *EndAddress);
public:
RuntimeDyldImpl(RTDyldMemoryManager *mm) : MemMgr(mm), HasError(false) {}
virtual ~RuntimeDyldImpl();
virtual bool loadObject(MemoryBuffer *InputBuffer) = 0;
void *getSymbolAddress(StringRef Name) {
// FIXME: Just look up as a function for now. Overly simple of course.
// Work in progress.
return SymbolTable.lookup(Name);
}
void resolveRelocations();
virtual void reassignSymbolAddress(StringRef Name, uint8_t *Addr) = 0;
// 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;
};
class RuntimeDyldMachO : public RuntimeDyldImpl {
// 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.
struct RelocationEntry {
std::string Target; // Object this relocation is contained in.
uint64_t Offset; // Offset into the object for the relocation.
uint32_t Data; // Second word of the raw macho relocation entry.
int64_t Addend; // Addend encoded in the instruction itself, if any.
bool isResolved; // Has this relocation been resolved previously?
RelocationEntry(StringRef t, uint64_t offset, uint32_t data, int64_t addend)
: Target(t), Offset(offset), Data(data), Addend(addend),
isResolved(false) {}
};
typedef SmallVector<RelocationEntry, 4> RelocationList;
StringMap<RelocationList> Relocations;
// FIXME: Also keep a map of all the relocations contained in an object. Use
// this to dynamically answer whether all of the relocations in it have
// been resolved or not.
bool resolveRelocation(uint8_t *Address, uint8_t *Value, bool isPCRel,
unsigned Type, unsigned Size);
bool resolveX86_64Relocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
unsigned Type, unsigned Size);
bool resolveARMRelocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
unsigned Type, unsigned Size);
bool loadSegment32(const MachOObject *Obj,
const MachOObject::LoadCommandInfo *SegmentLCI,
const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
bool loadSegment64(const MachOObject *Obj,
const MachOObject::LoadCommandInfo *SegmentLCI,
const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
public:
RuntimeDyldMachO(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
bool loadObject(MemoryBuffer *InputBuffer);
void reassignSymbolAddress(StringRef Name, uint8_t *Addr);
static bool isKnownFormat(const MemoryBuffer *InputBuffer);
bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
return isKnownFormat(InputBuffer);
}
};
} // end namespace llvm
#endif
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