path: root/lib/ExecutionEngine/JIT/JITEmitter.cpp

//===-- JITEmitter.cpp - Write machine code to executable memory ----------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a MachineCodeEmitter object that is used by the JIT to
// write machine code to memory and remember where relocatable values are.
//
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "jit"
#include "JIT.h"
#include "JITDwarfEmitter.h"
#include "llvm/Constants.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRelocation.h"
#include "llvm/ExecutionEngine/JITMemoryManager.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetJITInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MutexGuard.h"
#include "llvm/System/Disassembler.h"
#include "llvm/System/Memory.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include <algorithm>
#ifndef NDEBUG
#include <iomanip>
#endif
using namespace llvm;

STATISTIC(NumBytes, "Number of bytes of machine code compiled");
STATISTIC(NumRelos, "Number of relocations applied");
static JIT *TheJIT = 0;


//===----------------------------------------------------------------------===//
// JIT lazy compilation code.
//
namespace {
  class JITResolverState {
  private:
    /// FunctionToStubMap - Keep track of the stub created for a particular
    /// function so that we can reuse them if necessary.
    std::map<Function*, void*> FunctionToStubMap;

    /// StubToFunctionMap - Keep track of the function that each stub
    /// corresponds to.
    std::map<void*, Function*> StubToFunctionMap;

    /// GlobalToNonLazyPtrMap - Keep track of the lazy pointer created for a
    /// particular GlobalVariable so that we can reuse them if necessary.
    std::map<GlobalValue*, void*> GlobalToNonLazyPtrMap;

  public:
    std::map<Function*, void*>& getFunctionToStubMap(const MutexGuard& locked) {
      assert(locked.holds(TheJIT->lock));
      return FunctionToStubMap;
    }

    std::map<void*, Function*>& getStubToFunctionMap(const MutexGuard& locked) {
      assert(locked.holds(TheJIT->lock));
      return StubToFunctionMap;
    }

    std::map<GlobalValue*, void*>&
    getGlobalToNonLazyPtrMap(const MutexGuard& locked) {
      assert(locked.holds(TheJIT->lock));
      return GlobalToNonLazyPtrMap;
    }
  };

  /// JITResolver - Keep track of, and resolve, call sites for functions that
  /// have not yet been compiled.
  class JITResolver {
    /// LazyResolverFn - The target lazy resolver function that we actually
    /// rewrite instructions to use.
    TargetJITInfo::LazyResolverFn LazyResolverFn;

    JITResolverState state;

    /// ExternalFnToStubMap - This is the equivalent of FunctionToStubMap for
    /// external functions.
    std::map<void*, void*> ExternalFnToStubMap;

    //map addresses to indexes in the GOT
    std::map<void*, unsigned> revGOTMap;
    unsigned nextGOTIndex;

    static JITResolver *TheJITResolver;
  public:
    explicit JITResolver(JIT &jit) : nextGOTIndex(0) {
      TheJIT = &jit;

      LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
      assert(TheJITResolver == 0 &&