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Diffstat (limited to 'lib/EntoSA/SVals.cpp')
-rw-r--r-- | lib/EntoSA/SVals.cpp | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/lib/EntoSA/SVals.cpp b/lib/EntoSA/SVals.cpp new file mode 100644 index 0000000000..ea23293924 --- /dev/null +++ b/lib/EntoSA/SVals.cpp @@ -0,0 +1,361 @@ +//= 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/EntoSA/PathSensitive/GRState.h" +#include "clang/Basic/IdentifierTable.h" + +using namespace clang; +using namespace ento; +using llvm::dyn_cast; +using llvm::cast; +using llvm::APSInt; + +//===----------------------------------------------------------------------===// +// Symbol iteration within an SVal. +//===----------------------------------------------------------------------===// + + +//===----------------------------------------------------------------------===// +// Utility methods. +//===----------------------------------------------------------------------===// + +bool SVal::hasConjuredSymbol() const { + if (const nonloc::SymbolVal* SV = dyn_cast<nonloc::SymbolVal>(this)) { + SymbolRef sym = SV->getSymbol(); + if (isa<SymbolConjured>(sym)) + return true; + } + + if (const loc::MemRegionVal *RV = dyn_cast<loc::MemRegionVal>(this)) { + const MemRegion *R = RV->getRegion(); + if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) { + SymbolRef sym = SR->getSymbol(); + if (isa<SymbolConjured>(sym)) + return true; + } + } + + return false; +} + +const FunctionDecl *SVal::getAsFunctionDecl() const { + if (const loc::MemRegionVal* X = dyn_cast<loc::MemRegionVal>(this)) { + const MemRegion* R = X->getRegion(); + if (const FunctionTextRegion *CTR = R->getAs<FunctionTextRegion>()) + return CTR->getDecl(); + } + + return NULL; +} + +/// getAsLocSymbol - If this SVal is a location (subclasses Loc) and +/// wraps a symbol, return that SymbolRef. Otherwise return 0. +// FIXME: should we consider SymbolRef wrapped in CodeTextRegion? +SymbolRef SVal::getAsLocSymbol() const { + if (const nonloc::LocAsInteger *X = dyn_cast<nonloc::LocAsInteger>(this)) + return X->getLoc().getAsLocSymbol(); + + if (const loc::MemRegionVal *X = dyn_cast<loc::MemRegionVal>(this)) { + const MemRegion *R = X->StripCasts(); + if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(R)) + return SymR->getSymbol(); + } + return NULL; +} + +/// Get the symbol in the SVal or its base region. +SymbolRef SVal::getLocSymbolInBase() const { + const loc::MemRegionVal *X = dyn_cast<loc::MemRegionVal>(this); + + if (!X) + return 0; + + const MemRegion *R = X->getRegion(); + + while (const SubRegion *SR = dyn_cast<SubRegion>(R)) { + if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(SR)) + return SymR->getSymbol(); + else + R = SR->getSuperRegion(); + } + + return 0; +} + +/// getAsSymbol - If this Sval wraps a symbol return that SymbolRef. +/// Otherwise return 0. +// FIXME: should we consider SymbolRef wrapped in CodeTextRegion? +SymbolRef SVal::getAsSymbol() const { + if (const nonloc::SymbolVal *X = dyn_cast<nonloc::SymbolVal>(this)) + return X->getSymbol(); + + if (const nonloc::SymExprVal *X = dyn_cast<nonloc::SymExprVal>(this)) + if (SymbolRef Y = dyn_cast<SymbolData>(X->getSymbolicExpression())) + return Y; + + return getAsLocSymbol(); +} + +/// getAsSymbolicExpression - If this Sval wraps a symbolic expression then +/// return that expression. Otherwise return NULL. +const SymExpr *SVal::getAsSymbolicExpression() const { + if (const nonloc::SymExprVal *X = dyn_cast<nonloc::SymExprVal>(this)) + return X->getSymbolicExpression(); + + return getAsSymbol(); +} + +const MemRegion *SVal::getAsRegion() const { + if (const loc::MemRegionVal *X = dyn_cast<loc::MemRegionVal>(this)) + return X->getRegion(); + + if (const nonloc::LocAsInteger *X = dyn_cast<nonloc::LocAsInteger>(this)) { + return X->getLoc().getAsRegion(); + } + + return 0; +} + +const MemRegion *loc::MemRegionVal::StripCasts() const { + const MemRegion *R = getRegion(); + return R ? R->StripCasts() : NULL; +} + +bool SVal::symbol_iterator::operator==(const symbol_iterator &X) const { + return itr == X.itr; +} + +bool SVal::symbol_iterator::operator!=(const symbol_iterator &X) const { + return itr != X.itr; +} + +SVal::symbol_iterator::symbol_iterator(const SymExpr *SE) { + itr.push_back(SE); + while (!isa<SymbolData>(itr.back())) expand(); +} + +SVal::symbol_iterator& SVal::symbol_iterator::operator++() { + assert(!itr.empty() && "attempting to iterate on an 'end' iterator"); + assert(isa<SymbolData>(itr.back())); + itr.pop_back(); + if (!itr.empty()) + while (!isa<SymbolData>(itr.back())) expand(); + return *this; +} + +SymbolRef SVal::symbol_iterator::operator*() { + assert(!itr.empty() && "attempting to dereference an 'end' iterator"); + return cast<SymbolData>(itr.back()); +} + +void SVal::symbol_iterator::expand() { + const SymExpr *SE = itr.back(); + itr.pop_back(); + + if (const SymIntExpr *SIE = dyn_cast<SymIntExpr>(SE)) { + itr.push_back(SIE->getLHS()); + return; + } + else if (const SymSymExpr *SSE = dyn_cast<SymSymExpr>(SE)) { + itr.push_back(SSE->getLHS()); + itr.push_back(SSE->getRHS()); + return; + } + + assert(false && "unhandled expansion case"); +} + +const void *nonloc::LazyCompoundVal::getStore() const { + return static_cast<const LazyCompoundValData*>(Data)->getStore(); +} + +const TypedRegion *nonloc::LazyCompoundVal::getRegion() const { + return static_cast<const LazyCompoundValData*>(Data)->getRegion(); +} + +//===----------------------------------------------------------------------===// +// 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::isConstant() const { + return isa<nonloc::ConcreteInt>(this) || isa<loc::ConcreteInt>(this); +} + +bool SVal::isConstant(int I) const { + if (isa<loc::ConcreteInt>(*this)) + return cast<loc::ConcreteInt>(*this).getValue() == I; + else if (isa<nonloc::ConcreteInt>(*this)) + return cast<nonloc::ConcreteInt>(*this).getValue() == I; + else + return false; +} + +bool SVal::isZeroConstant() const { + return isConstant(0); +} + + +//===----------------------------------------------------------------------===// +// Transfer function dispatch for Non-Locs. +//===----------------------------------------------------------------------===// + +SVal nonloc::ConcreteInt::evalBinOp(SValBuilder &svalBuilder, + BinaryOperator::Opcode Op, + const nonloc::ConcreteInt& R) const { + const llvm::APSInt* X = + svalBuilder.getBasicValueFactory().evalAPSInt(Op, getValue(), R.getValue()); + + if (X) + return nonloc::ConcreteInt(*X); + else + return UndefinedVal(); +} + +nonloc::ConcreteInt +nonloc::ConcreteInt::evalComplement(SValBuilder &svalBuilder) const { + return svalBuilder.makeIntVal(~getValue()); +} + +nonloc::ConcreteInt +nonloc::ConcreteInt::evalMinus(SValBuilder &svalBuilder) const { + return svalBuilder.makeIntVal(-getValue()); +} + +//===----------------------------------------------------------------------===// +// Transfer function dispatch for Locs. +//===----------------------------------------------------------------------===// + +SVal loc::ConcreteInt::evalBinOp(BasicValueFactory& BasicVals, + BinaryOperator::Opcode Op, + const loc::ConcreteInt& R) const { + + assert (Op == BO_Add || Op == BO_Sub || + (Op >= BO_LT && Op <= BO_NE)); + + const llvm::APSInt* X = BasicVals.evalAPSInt(Op, getValue(), R.getValue()); + + if (X) + return loc::ConcreteInt(*X); + else + return UndefinedVal(); +} + +//===----------------------------------------------------------------------===// +// Pretty-Printing. +//===----------------------------------------------------------------------===// + +void SVal::dump() const { dumpToStream(llvm::errs()); } + +void SVal::dumpToStream(llvm::raw_ostream& os) const { + switch (getBaseKind()) { + case UnknownKind: + os << "Unknown"; + break; + case NonLocKind: + cast<NonLoc>(this)->dumpToStream(os); + break; + case LocKind: + cast<Loc>(this)->dumpToStream(os); + break; + case UndefinedKind: + os << "Undefined"; + break; + default: + assert (false && "Invalid SVal."); + } +} + +void NonLoc::dumpToStream(llvm::raw_ostream& os) const { + switch (getSubKind()) { + case nonloc::ConcreteIntKind: { + const nonloc::ConcreteInt& C = *cast<nonloc::ConcreteInt>(this); + if (C.getValue().isUnsigned()) + os << C.getValue().getZExtValue(); + else + os << C.getValue().getSExtValue(); + os << ' ' << (C.getValue().isUnsigned() ? 'U' : 'S') + << C.getValue().getBitWidth() << 'b'; + break; + } + case nonloc::SymbolValKind: + os << '$' << cast<nonloc::SymbolVal>(this)->getSymbol(); + break; + case nonloc::SymExprValKind: { + const nonloc::SymExprVal& C = *cast<nonloc::SymExprVal>(this); + const SymExpr *SE = C.getSymbolicExpression(); + os << SE; + break; + } + case nonloc::LocAsIntegerKind: { + const nonloc::LocAsInteger& C = *cast<nonloc::LocAsInteger>(this); + os << C.getLoc() << " [as " << C.getNumBits() << " bit integer]"; + break; + } + case nonloc::CompoundValKind: { + const nonloc::CompoundVal& C = *cast<nonloc::CompoundVal>(this); + os << "compoundVal{"; + bool first = true; + for (nonloc::CompoundVal::iterator I=C.begin(), E=C.end(); I!=E; ++I) { + if (first) { + os << ' '; first = false; + } + else + os << ", "; + + (*I).dumpToStream(os); + } + os << "}"; + break; + } + case nonloc::LazyCompoundValKind: { + const nonloc::LazyCompoundVal &C = *cast<nonloc::LazyCompoundVal>(this); + os << "lazyCompoundVal{" << const_cast<void *>(C.getStore()) + << ',' << C.getRegion() + << '}'; + break; + } + default: + assert (false && "Pretty-printed not implemented for this NonLoc."); + break; + } +} + +void Loc::dumpToStream(llvm::raw_ostream& os) const { + switch (getSubKind()) { + case loc::ConcreteIntKind: + os << cast<loc::ConcreteInt>(this)->getValue().getZExtValue() << " (Loc)"; + break; + case loc::GotoLabelKind: + os << "&&" << cast<loc::GotoLabel>(this)->getLabel()->getID()->getName(); + break; + case loc::MemRegionKind: + os << '&' << cast<loc::MemRegionVal>(this)->getRegion()->getString(); + break; + default: + assert(false && "Pretty-printing not implemented for this Loc."); + break; + } +} |