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//===-- Checks.cpp --------------------------------------------------------===//
//
// The KLEE Symbolic Virtual Machine
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "Passes.h"
#include "klee/Config/Version.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/Pass.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
using namespace llvm;
using namespace klee;
char DivCheckPass::ID;
bool DivCheckPass::runOnModule(Module &M) {
Function *divZeroCheckFunction = 0;
LLVMContext &ctx = M.getContext();
bool moduleChanged = false;
for (Module::iterator f = M.begin(), fe = M.end(); f != fe; ++f) {
for (Function::iterator b = f->begin(), be = f->end(); b != be; ++b) {
for (BasicBlock::iterator i = b->begin(), ie = b->end(); i != ie; ++i) {
if (BinaryOperator* binOp = dyn_cast<BinaryOperator>(i)) {
// find all [s|u][div|mod] instructions
Instruction::BinaryOps opcode = binOp->getOpcode();
if (opcode == Instruction::SDiv || opcode == Instruction::UDiv ||
opcode == Instruction::SRem || opcode == Instruction::URem) {
CastInst *denominator =
CastInst::CreateIntegerCast(i->getOperand(1),
Type::getInt64Ty(ctx),
false, /* sign doesn't matter */
"int_cast_to_i64",
&*i);
// Lazily bind the function to avoid always importing it.
if (!divZeroCheckFunction) {
Constant *fc = M.getOrInsertFunction("klee_div_zero_check",
Type::getVoidTy(ctx),
Type::getInt64Ty(ctx),
NULL);
divZeroCheckFunction = cast<Function>(fc);
}
CallInst * ci = CallInst::Create(divZeroCheckFunction, denominator, "", &*i);
// Set debug location of checking call to that of the div/rem
// operation so error locations are reported in the correct
// location.
ci->setDebugLoc(binOp->getDebugLoc());
moduleChanged = true;
}
}
}
}
}
return moduleChanged;
}
char OvershiftCheckPass::ID;
bool OvershiftCheckPass::runOnModule(Module &M) {
Function *overshiftCheckFunction = 0;
LLVMContext &ctx = M.getContext();
bool moduleChanged = false;
for (Module::iterator f = M.begin(), fe = M.end(); f != fe; ++f) {
for (Function::iterator b = f->begin(), be = f->end(); b != be; ++b) {
for (BasicBlock::iterator i = b->begin(), ie = b->end(); i != ie; ++i) {
if (BinaryOperator* binOp = dyn_cast<BinaryOperator>(i)) {
// find all shift instructions
Instruction::BinaryOps opcode = binOp->getOpcode();
if (opcode == Instruction::Shl ||
opcode == Instruction::LShr ||
opcode == Instruction::AShr ) {
std::vector<llvm::Value*> args;
// Determine bit width of first operand
uint64_t bitWidth=i->getOperand(0)->getType()->getScalarSizeInBits();
ConstantInt *bitWidthC = ConstantInt::get(Type::getInt64Ty(ctx),
bitWidth, false);
args.push_back(bitWidthC);
CastInst *shift =
CastInst::CreateIntegerCast(i->getOperand(1),
Type::getInt64Ty(ctx),
false, /* sign doesn't matter */
"int_cast_to_i64",
&*i);
args.push_back(shift);
// Lazily bind the function to avoid always importing it.
if (!overshiftCheckFunction) {
Constant *fc = M.getOrInsertFunction("klee_overshift_check",
Type::getVoidTy(ctx),
Type::getInt64Ty(ctx),
Type::getInt64Ty(ctx),
NULL);
overshiftCheckFunction = cast<Function>(fc);
}
// Inject CallInstr to check if overshifting possible
CallInst *ci =
CallInst::Create(overshiftCheckFunction, args, "", &*i);
// set debug information from binary operand to preserve it
ci->setDebugLoc(binOp->getDebugLoc());
moduleChanged = true;
}
}
}
}
}
return moduleChanged;
}
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