path: root/lib/ExecutionEngine/Interpreter/Execution.cpp

//===-- Execution.cpp - Implement code to simulate the program ------------===//
// 
//  This file contains the actual instruction interpreter.
//
//===----------------------------------------------------------------------===//

#include "Interpreter.h"
#include "ExecutionAnnotations.h"
#include "llvm/Module.h"
#include "llvm/Instructions.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
#include "llvm/Assembly/Writer.h"
#include "Support/CommandLine.h"
#include "Support/Statistic.h"
#include <math.h>  // For fmod
#include <signal.h>
#include <setjmp.h>

Interpreter *TheEE = 0;

namespace {
  Statistic<> NumDynamicInsts("lli", "Number of dynamic instructions executed");

  cl::opt<bool>
  QuietMode("quiet", cl::desc("Do not emit any non-program output"),
	    cl::init(true));

  cl::alias 
  QuietModeA("q", cl::desc("Alias for -quiet"), cl::aliasopt(QuietMode));

  cl::opt<bool>
  ArrayChecksEnabled("array-checks", cl::desc("Enable array bound checks"));
}

// Create a TargetData structure to handle memory addressing and size/alignment
// computations
//
CachedWriter CW;     // Object to accelerate printing of LLVM

sigjmp_buf SignalRecoverBuffer;
static bool InInstruction = false;

extern "C" {
static void SigHandler(int Signal) {
  if (InInstruction)
    siglongjmp(SignalRecoverBuffer, Signal);
}
}

static void initializeSignalHandlers() {
  struct sigaction Action;
  Action.sa_handler = SigHandler;
  Action.sa_flags   = SA_SIGINFO;
  sigemptyset(&Action.sa_mask);
  sigaction(SIGSEGV, &Action, 0);
  sigaction(SIGBUS, &Action, 0);
  sigaction(SIGINT, &Action, 0);
  sigaction(SIGFPE, &Action, 0);
}


//===----------------------------------------------------------------------===//
//                     Value Manipulation code
//===----------------------------------------------------------------------===//

static unsigned getOperandSlot(Value *V) {
  SlotNumber *SN = (SlotNumber*)V->getAnnotation(SlotNumberAID);
  assert(SN && "Operand does not have a slot number annotation!");
  return SN->SlotNum;
}

// Operations used by constant expr implementations...
static GenericValue executeCastOperation(Value *Src, const Type *DestTy,
                                         ExecutionContext &SF);
static GenericValue executeAddInst(GenericValue Src1, GenericValue Src2, 
				   const Type *Ty);


static GenericValue getOperandValue(Value *V, ExecutionContext &SF) {
  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
    switch (CE->getOpcode()) {
    case Instruction::Cast:
      return executeCastOperation(CE->getOperand(0), CE->getType(), SF);
    case Instruction::GetElementPtr:
      return TheEE->executeGEPOperation(CE->getOperand(0), CE->op_begin()+1,
					CE->op_end(), SF);
    case Instruction::Add:
      return executeAddInst(getOperandValue(CE->getOperand(0), SF),
                            getOperandValue(CE->getOperand(1), SF),
                            CE->getType());
    default:
      std::cerr << "Unhandled ConstantExpr: " << CE << "\n";
      abort();
      return GenericValue();
    }
  } else if (Constant *CPV = dyn_cast<Constant>(V)) {
    return TheEE->getConstantValue(CPV);
  } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
    return PTOGV(TheEE->getPointerToGlobal(GV));
  } else {
    unsigned TyP = V->getType()->getUniqueID();   // TypePlane for value
    unsigned OpSlot = getOperandSlot(V);
    assert(TyP < SF