llvm-project/clang/lib/Analysis/SVals.cpp

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//= RValues.cpp - Abstract RValues for Path-Sens. Value Tracking -*- 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 SVal, Loc, and NonLoc, classes that represent
// abstract r-values for use with path-sensitive value tracking.
//
//===----------------------------------------------------------------------===//
#include "clang/Analysis/PathSensitive/GRState.h"
#include "clang/Basic/IdentifierTable.h"
#include "llvm/Support/Streams.h"
using namespace clang;
using llvm::dyn_cast;
using llvm::cast;
using llvm::APSInt;
//===----------------------------------------------------------------------===//
// Symbol Iteration.
//===----------------------------------------------------------------------===//
SVal::symbol_iterator SVal::symbol_begin() const {
// FIXME: This is a rat's nest. Cleanup.
if (isa<loc::SymbolVal>(this))
return symbol_iterator(SymbolRef((uintptr_t)Data));
else if (isa<nonloc::SymbolVal>(this))
return symbol_iterator(SymbolRef((uintptr_t)Data));
else if (isa<nonloc::SymIntConstraintVal>(this)) {
const SymIntConstraint& C =
cast<nonloc::SymIntConstraintVal>(this)->getConstraint();
return symbol_iterator(C.getSymbol());
}
else if (isa<nonloc::LocAsInteger>(this)) {
const nonloc::LocAsInteger& V = cast<nonloc::LocAsInteger>(*this);
return V.getPersistentLoc().symbol_begin();
}
else if (isa<loc::MemRegionVal>(this)) {
const MemRegion* R = cast<loc::MemRegionVal>(this)->getRegion();
if (const SymbolicRegion* S = dyn_cast<SymbolicRegion>(R))
return symbol_iterator(S->getSymbol());
}
return symbol_iterator();
}
SVal::symbol_iterator SVal::symbol_end() const {
return symbol_iterator();
}
//===----------------------------------------------------------------------===//
// Other Iterators.
//===----------------------------------------------------------------------===//
nonloc::CompoundVal::iterator nonloc::CompoundVal::begin() const {
return getValue()->begin();
}
nonloc::CompoundVal::iterator nonloc::CompoundVal::end() const {
return getValue()->end();
}
//===----------------------------------------------------------------------===//
// Useful predicates.
//===----------------------------------------------------------------------===//
bool SVal::isZeroConstant() const {
if (isa<loc::ConcreteInt>(*this))
return cast<loc::ConcreteInt>(*this).getValue() == 0;
else if (isa<nonloc::ConcreteInt>(*this))
return cast<nonloc::ConcreteInt>(*this).getValue() == 0;
else
return false;
}
//===----------------------------------------------------------------------===//
// Transfer function dispatch for Non-Locs.
//===----------------------------------------------------------------------===//
SVal nonloc::ConcreteInt::EvalBinOp(BasicValueFactory& BasicVals,
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BinaryOperator::Opcode Op,
const nonloc::ConcreteInt& R) const {
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const llvm::APSInt* X =
BasicVals.EvaluateAPSInt(Op, getValue(), R.getValue());
if (X)
return nonloc::ConcreteInt(*X);
else
return UndefinedVal();
}
// Bitwise-Complement.
nonloc::ConcreteInt
nonloc::ConcreteInt::EvalComplement(BasicValueFactory& BasicVals) const {
return BasicVals.getValue(~getValue());
}
// Unary Minus.
nonloc::ConcreteInt
nonloc::ConcreteInt::EvalMinus(BasicValueFactory& BasicVals, UnaryOperator* U) const {
assert (U->getType() == U->getSubExpr()->getType());
assert (U->getType()->isIntegerType());
return BasicVals.getValue(-getValue());
}
//===----------------------------------------------------------------------===//
// Transfer function dispatch for Locs.
//===----------------------------------------------------------------------===//
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SVal loc::ConcreteInt::EvalBinOp(BasicValueFactory& BasicVals,
BinaryOperator::Opcode Op,
const loc::ConcreteInt& R) const {
assert (Op == BinaryOperator::Add || Op == BinaryOperator::Sub ||
(Op >= BinaryOperator::LT && Op <= BinaryOperator::NE));
const llvm::APSInt* X = BasicVals.EvaluateAPSInt(Op, getValue(), R.getValue());
if (X)
return loc::ConcreteInt(*X);
else
return UndefinedVal();
}
NonLoc Loc::EQ(BasicValueFactory& BasicVals, const Loc& R) const {
switch (getSubKind()) {
default:
assert(false && "EQ not implemented for this Loc.");
break;
case loc::ConcreteIntKind:
if (isa<loc::ConcreteInt>(R)) {
bool b = cast<loc::ConcreteInt>(this)->getValue() ==
cast<loc::ConcreteInt>(R).getValue();
return NonLoc::MakeIntTruthVal(BasicVals, b);
}
else if (isa<loc::SymbolVal>(R)) {
const SymIntConstraint& C =
BasicVals.getConstraint(cast<loc::SymbolVal>(R).getSymbol(),
BinaryOperator::EQ,
cast<loc::ConcreteInt>(this)->getValue());
return nonloc::SymIntConstraintVal(C);
}
break;
case loc::SymbolValKind: {
if (isa<loc::ConcreteInt>(R)) {
const SymIntConstraint& C =
BasicVals.getConstraint(cast<loc::SymbolVal>(this)->getSymbol(),
BinaryOperator::EQ,
cast<loc::ConcreteInt>(R).getValue());
return nonloc::SymIntConstraintVal(C);
}
assert (!isa<loc::SymbolVal>(R) && "FIXME: Implement unification.");
break;
}
case loc::MemRegionKind:
if (isa<loc::MemRegionVal>(R)) {
bool b = cast<loc::MemRegionVal>(*this) == cast<loc::MemRegionVal>(R);
return NonLoc::MakeIntTruthVal(BasicVals, b);
}
break;
}
return NonLoc::MakeIntTruthVal(BasicVals, false);
}
NonLoc Loc::NE(BasicValueFactory& BasicVals, const Loc& R) const {
switch (getSubKind()) {
default:
assert(false && "NE not implemented for this Loc.");
break;
case loc::ConcreteIntKind:
if (isa<loc::ConcreteInt>(R)) {
bool b = cast<loc::ConcreteInt>(this)->getValue() !=
cast<loc::ConcreteInt>(R).getValue();
return NonLoc::MakeIntTruthVal(BasicVals, b);
}
else if (isa<loc::SymbolVal>(R)) {
const SymIntConstraint& C =
BasicVals.getConstraint(cast<loc::SymbolVal>(R).getSymbol(),
BinaryOperator::NE,
cast<loc::ConcreteInt>(this)->getValue());
return nonloc::SymIntConstraintVal(C);
}
break;
case loc::SymbolValKind: {
if (isa<loc::ConcreteInt>(R)) {
const SymIntConstraint& C =
BasicVals.getConstraint(cast<loc::SymbolVal>(this)->getSymbol(),
BinaryOperator::NE,
cast<loc::ConcreteInt>(R).getValue());
return nonloc::SymIntConstraintVal(C);
}
assert (!isa<loc::SymbolVal>(R) && "FIXME: Implement sym !=.");
break;
}
case loc::MemRegionKind:
if (isa<loc::MemRegionVal>(R)) {
bool b = cast<loc::MemRegionVal>(*this)==cast<loc::MemRegionVal>(R);
return NonLoc::MakeIntTruthVal(BasicVals, b);
}
break;
}
return NonLoc::MakeIntTruthVal(BasicVals, true);
}
//===----------------------------------------------------------------------===//
// Utility methods for constructing Non-Locs.
//===----------------------------------------------------------------------===//
NonLoc NonLoc::MakeVal(SymbolRef sym) {
return nonloc::SymbolVal(sym);
}
NonLoc NonLoc::MakeVal(BasicValueFactory& BasicVals, unsigned X,
bool isUnsigned) {
return nonloc::ConcreteInt(BasicVals.getValue(X, sizeof(unsigned)*8,
isUnsigned));
}
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NonLoc NonLoc::MakeVal(BasicValueFactory& BasicVals, uint64_t X,
unsigned BitWidth, bool isUnsigned) {
return nonloc::ConcreteInt(BasicVals.getValue(X, BitWidth, isUnsigned));
}
NonLoc NonLoc::MakeVal(BasicValueFactory& BasicVals, uint64_t X, QualType T) {
return nonloc::ConcreteInt(BasicVals.getValue(X, T));
}
NonLoc NonLoc::MakeVal(BasicValueFactory& BasicVals, IntegerLiteral* I) {
return nonloc::ConcreteInt(BasicVals.getValue(APSInt(I->getValue(),
I->getType()->isUnsignedIntegerType())));
}
NonLoc NonLoc::MakeVal(BasicValueFactory& BasicVals, const llvm::APInt& I,
bool isUnsigned) {
return nonloc::ConcreteInt(BasicVals.getValue(I, isUnsigned));
}
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NonLoc NonLoc::MakeVal(BasicValueFactory& BasicVals, const llvm::APSInt& I) {
return nonloc::ConcreteInt(BasicVals.getValue(I));
}
NonLoc NonLoc::MakeIntTruthVal(BasicValueFactory& BasicVals, bool b) {
return nonloc::ConcreteInt(BasicVals.getTruthValue(b));
}
NonLoc NonLoc::MakeCompoundVal(QualType T, llvm::ImmutableList<SVal> Vals,
BasicValueFactory& BasicVals) {
return nonloc::CompoundVal(BasicVals.getCompoundValData(T, Vals));
}
SVal SVal::MakeSymbolValue(SymbolManager& SymMgr, const MemRegion* R,
QualType T) {
if (Loc::IsLocType(T))
return Loc::MakeVal(SymMgr.getSymbol(R));
else
return NonLoc::MakeVal(SymMgr.getSymbol(R));
}
SVal SVal::GetSymbolValue(SymbolManager& SymMgr, VarDecl* D) {
QualType T = D->getType();
if (Loc::IsLocType(T))
return loc::SymbolVal(SymMgr.getSymbol(D));
return nonloc::SymbolVal(SymMgr.getSymbol(D));
}
SVal SVal::getSymbolValue(SymbolManager& SymMgr, const MemRegion* R,
const llvm::APSInt* Idx, QualType T) {
if (Loc::IsLocType(T))
return loc::SymbolVal(SymMgr.getElementSymbol(R, Idx));
else
return nonloc::SymbolVal(SymMgr.getElementSymbol(R, Idx));
}
SVal SVal::getSymbolValue(SymbolManager& SymMgr, const MemRegion* R,
const FieldDecl* FD, QualType T) {
if (Loc::IsLocType(T))
return loc::SymbolVal(SymMgr.getFieldSymbol(R, FD));
else
return nonloc::SymbolVal(SymMgr.getFieldSymbol(R, FD));
}
nonloc::LocAsInteger nonloc::LocAsInteger::Make(BasicValueFactory& Vals, Loc V,
unsigned Bits) {
return LocAsInteger(Vals.getPersistentSValWithData(V, Bits));
}
//===----------------------------------------------------------------------===//
// Utility methods for constructing Locs.
//===----------------------------------------------------------------------===//
Loc Loc::MakeVal(const MemRegion* R) { return loc::MemRegionVal(R); }
Loc Loc::MakeVal(AddrLabelExpr* E) { return loc::GotoLabel(E->getLabel()); }
Loc Loc::MakeVal(SymbolRef sym) { return loc::SymbolVal(sym); }
//===----------------------------------------------------------------------===//
// Pretty-Printing.
//===----------------------------------------------------------------------===//
void SVal::printStdErr() const { print(llvm::errs()); llvm::errs().flush(); }
void SVal::print(std::ostream& Out) const {
llvm::raw_os_ostream out(Out);
print(out);
}
void SVal::print(llvm::raw_ostream& Out) const {
switch (getBaseKind()) {
case UnknownKind:
Out << "Invalid"; break;
case NonLocKind:
cast<NonLoc>(this)->print(Out); break;
case LocKind:
cast<Loc>(this)->print(Out); break;
case UndefinedKind:
Out << "Undefined"; break;
default:
assert (false && "Invalid SVal.");
}
}
static void printOpcode(llvm::raw_ostream& Out, BinaryOperator::Opcode Op) {
switch (Op) {
case BinaryOperator::Mul: Out << '*' ; break;
case BinaryOperator::Div: Out << '/' ; break;
case BinaryOperator::Rem: Out << '%' ; break;
case BinaryOperator::Add: Out << '+' ; break;
case BinaryOperator::Sub: Out << '-' ; break;
case BinaryOperator::Shl: Out << "<<" ; break;
case BinaryOperator::Shr: Out << ">>" ; break;
case BinaryOperator::LT: Out << "<" ; break;
case BinaryOperator::GT: Out << '>' ; break;
case BinaryOperator::LE: Out << "<=" ; break;
case BinaryOperator::GE: Out << ">=" ; break;
case BinaryOperator::EQ: Out << "==" ; break;
case BinaryOperator::NE: Out << "!=" ; break;
case BinaryOperator::And: Out << '&' ; break;
case BinaryOperator::Xor: Out << '^' ; break;
case BinaryOperator::Or: Out << '|' ; break;
default: assert(false && "Not yet implemented.");
}
}
void NonLoc::print(llvm::raw_ostream& Out) const {
switch (getSubKind()) {
case nonloc::ConcreteIntKind:
Out << cast<nonloc::ConcreteInt>(this)->getValue().getZExtValue();
if (cast<nonloc::ConcreteInt>(this)->getValue().isUnsigned())
Out << 'U';
break;
case nonloc::SymbolValKind:
Out << '$' << cast<nonloc::SymbolVal>(this)->getSymbol();
break;
case nonloc::SymIntConstraintValKind: {
const nonloc::SymIntConstraintVal& C =
*cast<nonloc::SymIntConstraintVal>(this);
Out << '$' << C.getConstraint().getSymbol() << ' ';
printOpcode(Out, C.getConstraint().getOpcode());
Out << ' ' << C.getConstraint().getInt().getZExtValue();
if (C.getConstraint().getInt().isUnsigned())
Out << 'U';
break;
}
case nonloc::LocAsIntegerKind: {
const nonloc::LocAsInteger& C = *cast<nonloc::LocAsInteger>(this);
C.getLoc().print(Out);
Out << " [as " << C.getNumBits() << " bit integer]";
break;
}
case nonloc::CompoundValKind: {
const nonloc::CompoundVal& C = *cast<nonloc::CompoundVal>(this);
Out << " {";
bool first = true;
for (nonloc::CompoundVal::iterator I=C.begin(), E=C.end(); I!=E; ++I) {
if (first) { Out << ' '; first = false; }
else Out << ", ";
(*I).print(Out);
}
Out << " }";
break;
}
default:
assert (false && "Pretty-printed not implemented for this NonLoc.");
break;
}
}
void Loc::print(llvm::raw_ostream& Out) const {
switch (getSubKind()) {
case loc::ConcreteIntKind:
Out << cast<loc::ConcreteInt>(this)->getValue().getZExtValue()
<< " (Loc)";
break;
case loc::SymbolValKind:
Out << '$' << cast<loc::SymbolVal>(this)->getSymbol();
break;
case loc::GotoLabelKind:
Out << "&&"
<< cast<loc::GotoLabel>(this)->getLabel()->getID()->getName();
break;
case loc::MemRegionKind:
Out << '&' << cast<loc::MemRegionVal>(this)->getRegion()->getString();
break;
case loc::FuncValKind:
Out << "function "
<< cast<loc::FuncVal>(this)->getDecl()->getIdentifier()->getName();
break;
default:
assert (false && "Pretty-printing not implemented for this Loc.");
break;
}
}