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//=== BasicValueFactory.cpp - Basic values for Path Sens analysis --*- C++ -*-//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines BasicValueFactory, a class that manages the lifetime
// of APSInt objects and symbolic constraints used by GRExprEngine
// and related classes.
//
//===----------------------------------------------------------------------===//
#include "clang/Analysis/PathSensitive/BasicValueFactory.h"
#include "clang/Analysis/PathSensitive/RValues.h"
using namespace clang;
typedef std::pair<RVal, unsigned> SizedRVal;
namespace llvm {
template<> struct FoldingSetTrait<SizedRVal> {
static inline void Profile(const SizedRVal& X, llvm::FoldingSetNodeID& ID) {
X.first.Profile(ID);
ID.AddInteger(X.second);
}
};
}
typedef llvm::FoldingSet<llvm::FoldingSetNodeWrapper<SizedRVal> >
PersistentRValsTy;
BasicValueFactory::~BasicValueFactory() {
// Note that the dstor for the contents of APSIntSet will never be called,
// so we iterate over the set and invoke the dstor for each APSInt. This
// frees an aux. memory allocated to represent very large constants.
for (APSIntSetTy::iterator I=APSIntSet.begin(), E=APSIntSet.end(); I!=E; ++I)
I->getValue().~APSInt();
delete (PersistentRValsTy*) PersistentRVals;
}
const llvm::APSInt& BasicValueFactory::getValue(const llvm::APSInt& X) {
llvm::FoldingSetNodeID ID;
void* InsertPos;
typedef llvm::FoldingSetNodeWrapper<llvm::APSInt> FoldNodeTy;
X.Profile(ID);
FoldNodeTy* P = APSIntSet.FindNodeOrInsertPos(ID, InsertPos);
if (!P) {
P = (FoldNodeTy*) BPAlloc.Allocate<FoldNodeTy>();
new (P) FoldNodeTy(X);
APSIntSet.InsertNode(P, InsertPos);
}
return *P;
}
const llvm::APSInt& BasicValueFactory::getValue(uint64_t X, unsigned BitWidth,
bool isUnsigned) {
llvm::APSInt V(BitWidth, isUnsigned);
V = X;
return getValue(V);
}
const llvm::APSInt& BasicValueFactory::getValue(uint64_t X, QualType T) {
unsigned bits = Ctx.getTypeSize(T);
llvm::APSInt V(bits, T->isUnsignedIntegerType());
V = X;
return getValue(V);
}
const SymIntConstraint&
BasicValueFactory::getConstraint(SymbolID sym, BinaryOperator::Opcode Op,
const llvm::APSInt& V) {
llvm::FoldingSetNodeID ID;
SymIntConstraint::Profile(ID, sym, Op, V);
void* InsertPos;
SymIntConstraint* C = SymIntCSet.FindNodeOrInsertPos(ID, InsertPos);
if (!C) {
C = (SymIntConstraint*) BPAlloc.Allocate<SymIntConstraint>();
new (C) SymIntConstraint(sym, Op, V);
SymIntCSet.InsertNode(C, InsertPos);
}
return *C;
}
const llvm::APSInt*
BasicValueFactory::EvaluateAPSInt(BinaryOperator::Opcode Op,
const llvm::APSInt& V1, const llvm::APSInt& V2) {
switch (Op) {
default:
assert (false && "Invalid Opcode.");
case BinaryOperator::Mul:
return &getValue( V1 * V2 );
case BinaryOperator::Div:
return &getValue( V1 / V2 );
case BinaryOperator::Rem:
return &getValue( V1 % V2 );
case BinaryOperator::Add:
return &getValue( V1 + V2 );
case BinaryOperator::Sub:
return &getValue( V1 - V2 );
case BinaryOperator::Shl: {
// FIXME: This logic should probably go higher up, where we can
// test these conditions symbolically.
// FIXME: Expand these checks to include all undefined behavior.
if (V2.isSigned() && V2.isNegative())
return NULL;
uint64_t Amt = V2.getZExtValue();
if (Amt > V1.getBitWidth())
return NULL;
return &getValue( V1.operator<<( (unsigned) Amt ));
}
case BinaryOperator::Shr: {
// FIXME: This logic should probably go higher up, where we can
// test these conditions symbolically.
// FIXME: Expand these checks to include all undefined behavior.
if (V2.isSigned() && V2.isNegative())
return NULL;
uint64_t Amt = V2.getZExtValue();
if (Amt > V1.getBitWidth())
return NULL;
return &getValue( V1.operator>>( (unsigned) Amt ));
}
case BinaryOperator::LT:
return &getTruthValue( V1 < V2 );
case BinaryOperator::GT:
return &getTruthValue( V1 > V2 );
case BinaryOperator::LE:
return &getTruthValue( V1 <= V2 );
case BinaryOperator::GE:
return &getTruthValue( V1 >= V2 );
case BinaryOperator::EQ:
return &getTruthValue( V1 == V2 );
case BinaryOperator::NE:
return &getTruthValue( V1 != V2 );
// Note: LAnd, LOr, Comma are handled specially by higher-level logic.
case BinaryOperator::And:
return &getValue( V1 & V2 );
case BinaryOperator::Or:
return &getValue( V1 | V2 );
case BinaryOperator::Xor:
return &getValue( V1 ^ V2 );
}
}
const std::pair<RVal, unsigned>&
BasicValueFactory::getPersistentSizedRVal(const RVal& V, unsigned Bits) {
// Lazily create the folding set.
if (!PersistentRVals) PersistentRVals = new PersistentRValsTy();
llvm::FoldingSetNodeID ID;
void* InsertPos;
V.Profile(ID);
ID.AddInteger(Bits);
PersistentRValsTy& Map = *((PersistentRValsTy*) PersistentRVals);
typedef llvm::FoldingSetNodeWrapper<SizedRVal> FoldNodeTy;
FoldNodeTy* P = Map.FindNodeOrInsertPos(ID, InsertPos);
if (!P) {
P = (FoldNodeTy*) BPAlloc.Allocate<FoldNodeTy>();
new (P) FoldNodeTy(std::make_pair(V, Bits));
Map.InsertNode(P, InsertPos);
}
return *P;
}
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