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//===-- ExecutorUtil.cpp --------------------------------------------------===//
//
// The KLEE Symbolic Virtual Machine
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "Executor.h"
#include "Context.h"
#include "klee/Expr.h"
#include "klee/Interpreter.h"
#include "klee/Solver.h"
#include "klee/Config/Version.h"
#include "klee/Internal/Module/KModule.h"
#include "klee/util/GetElementPtrTypeIterator.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/DataLayout.h"
#include <cassert>
using namespace klee;
using namespace llvm;
namespace klee {
ref<klee::ConstantExpr> Executor::evalConstant(const Constant *c) {
if (const llvm::ConstantExpr *ce = dyn_cast<llvm::ConstantExpr>(c)) {
return evalConstantExpr(ce);
} else {
if (const ConstantInt *ci = dyn_cast<ConstantInt>(c)) {
return ConstantExpr::alloc(ci->getValue());
} else if (const ConstantFP *cf = dyn_cast<ConstantFP>(c)) {
return ConstantExpr::alloc(cf->getValueAPF().bitcastToAPInt());
} else if (const GlobalValue *gv = dyn_cast<GlobalValue>(c)) {
return globalAddresses.find(gv)->second;
} else if (isa<ConstantPointerNull>(c)) {
return Expr::createPointer(0);
} else if (isa<UndefValue>(c) || isa<ConstantAggregateZero>(c)) {
return ConstantExpr::create(0, getWidthForLLVMType(c->getType()));
} else if (const ConstantDataSequential *cds =
dyn_cast<ConstantDataSequential>(c)) {
std::vector<ref<Expr> > kids;
for (unsigned i = 0, e = cds->getNumElements(); i != e; ++i) {
ref<Expr> kid = evalConstant(cds->getElementAsConstant(i));
kids.push_back(kid);
}
ref<Expr> res = ConcatExpr::createN(kids.size(), kids.data());
return cast<ConstantExpr>(res);
} else if (const ConstantStruct *cs = dyn_cast<ConstantStruct>(c)) {
const StructLayout *sl = kmodule->targetData->getStructLayout(cs->getType());
llvm::SmallVector<ref<Expr>, 4> kids;
for (unsigned i = cs->getNumOperands(); i != 0; --i) {
unsigned op = i-1;
ref<Expr> kid = evalConstant(cs->getOperand(op));
uint64_t thisOffset = sl->getElementOffsetInBits(op),
nextOffset = (op == cs->getNumOperands() - 1)
? sl->getSizeInBits()
: sl->getElementOffsetInBits(op+1);
if (nextOffset-thisOffset > kid->getWidth()) {
uint64_t paddingWidth = nextOffset-thisOffset-kid->getWidth();
kids.push_back(ConstantExpr::create(0, paddingWidth));
}
kids.push_back(kid);
}
ref<Expr> res = ConcatExpr::createN(kids.size(), kids.data());
return cast<ConstantExpr>(res);
} else if (const ConstantArray *ca = dyn_cast<ConstantArray>(c)){
llvm::SmallVector<ref<Expr>, 4> kids;
for (unsigned i = ca->getNumOperands(); i != 0; --i) {
unsigned op = i-1;
ref<Expr> kid = evalConstant(ca->getOperand(op));
kids.push_back(kid);
}
ref<Expr> res = ConcatExpr::createN(kids.size(), kids.data());
return cast<ConstantExpr>(res);
} else if (const ConstantVector *cv = dyn_cast<ConstantVector>(c)) {
llvm::SmallVector<ref<Expr>, 8> kids;
const size_t numOperands = cv->getNumOperands();
kids.reserve(numOperands);
for (unsigned i = 0; i < numOperands; ++i) {
kids.push_back(evalConstant(cv->getOperand(i)));
}
ref<Expr> res = ConcatExpr::createN(numOperands, kids.data());
assert(isa<ConstantExpr>(res) &&
"result of constant vector built is not a constant");
return cast<ConstantExpr>(res);
} else {
llvm::report_fatal_error("invalid argument to evalConstant()");
}
}
}
ref<ConstantExpr> Executor::evalConstantExpr(const llvm::ConstantExpr *ce) {
llvm::Type *type = ce->getType();
ref<ConstantExpr> op1(0), op2(0), op3(0);
int numOperands = ce->getNumOperands();
if (numOperands > 0) op1 = evalConstant(ce->getOperand(0));
if (numOperands > 1) op2 = evalConstant(ce->getOperand(1));
if (numOperands > 2) op3 = evalConstant(ce->getOperand(2));
switch (ce->getOpcode()) {
default :
ce->dump();
llvm::errs() << "error: unknown ConstantExpr type\n"
<< "opcode: " << ce->getOpcode() << "\n";
abort();
case Instruction::Trunc:
return op1->Extract(0, getWidthForLLVMType(type));
case Instruction::ZExt: return op1->ZExt(getWidthForLLVMType(type));
case Instruction::SExt: return op1->SExt(getWidthForLLVMType(type));
case Instruction::Add: return op1->Add(op2);
case Instruction::Sub: return op1->Sub(op2);
case Instruction::Mul: return op1->Mul(op2);
case Instruction::SDiv: return op1->SDiv(op2);
case Instruction::UDiv: return op1->UDiv(op2);
case Instruction::SRem: return op1->SRem(op2);
case Instruction::URem: return op1->URem(op2);
case Instruction::And: return op1->And(op2);
case Instruction::Or: return op1->Or(op2);
case Instruction::Xor: return op1->Xor(op2);
case Instruction::Shl: return op1->Shl(op2);
case Instruction::LShr: return op1->LShr(op2);
case Instruction::AShr: return op1->AShr(op2);
case Instruction::BitCast: return op1;
case Instruction::IntToPtr:
return op1->ZExt(getWidthForLLVMType(type));
case Instruction::PtrToInt:
return op1->ZExt(getWidthForLLVMType(type));
case Instruction::GetElementPtr: {
ref<ConstantExpr> base = op1->ZExt(Context::get().getPointerWidth());
for (gep_type_iterator ii = gep_type_begin(ce), ie = gep_type_end(ce);
ii != ie; ++ii) {
ref<ConstantExpr> addend =
ConstantExpr::alloc(0, Context::get().getPointerWidth());
if (StructType *st = dyn_cast<StructType>(*ii)) {
const StructLayout *sl = kmodule->targetData->getStructLayout(st);
const ConstantInt *ci = cast<ConstantInt>(ii.getOperand());
addend = ConstantExpr::alloc(sl->getElementOffset((unsigned)
ci->getZExtValue()),
Context::get().getPointerWidth());
} else {
const SequentialType *set = cast<SequentialType>(*ii);
ref<ConstantExpr> index =
evalConstant(cast<Constant>(ii.getOperand()));
unsigned elementSize =
kmodule->targetData->getTypeStoreSize(set->getElementType());
index = index->ZExt(Context::get().getPointerWidth());
addend = index->Mul(ConstantExpr::alloc(elementSize,
Context::get().getPointerWidth()));
}
base = base->Add(addend);
}
return base;
}
case Instruction::ICmp: {
switch(ce->getPredicate()) {
default: assert(0 && "unhandled ICmp predicate");
case ICmpInst::ICMP_EQ: return op1->Eq(op2);
case ICmpInst::ICMP_NE: return op1->Ne(op2);
case ICmpInst::ICMP_UGT: return op1->Ugt(op2);
case ICmpInst::ICMP_UGE: return op1->Uge(op2);
case ICmpInst::ICMP_ULT: return op1->Ult(op2);
case ICmpInst::ICMP_ULE: return op1->Ule(op2);
case ICmpInst::ICMP_SGT: return op1->Sgt(op2);
case ICmpInst::ICMP_SGE: return op1->Sge(op2);
case ICmpInst::ICMP_SLT: return op1->Slt(op2);
case ICmpInst::ICMP_SLE: return op1->Sle(op2);
}
}
case Instruction::Select:
return op1->isTrue() ? op2 : op3;
case Instruction::FAdd:
case Instruction::FSub:
case Instruction::FMul:
case Instruction::FDiv:
case Instruction::FRem:
case Instruction::FPTrunc:
case Instruction::FPExt:
case Instruction::UIToFP:
case Instruction::SIToFP:
case Instruction::FPToUI:
case Instruction::FPToSI:
case Instruction::FCmp:
assert(0 && "floating point ConstantExprs unsupported");
}
llvm_unreachable("Unsupported expression in evalConstantExpr");
return op1;
}
}
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