323 lines
10 KiB
C++
323 lines
10 KiB
C++
//= RValues.cpp - Abstract RValues for Path-Sens. Value Tracking -*- C++ -*-==//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines SVal, Loc, and NonLoc, classes that represent
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// abstract r-values for use with path-sensitive value tracking.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
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#include "clang/AST/ExprObjC.h"
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#include "clang/Basic/IdentifierTable.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace clang;
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using namespace ento;
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using llvm::APSInt;
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//===----------------------------------------------------------------------===//
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// Symbol iteration within an SVal.
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//===----------------------------------------------------------------------===//
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//===----------------------------------------------------------------------===//
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// Utility methods.
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//===----------------------------------------------------------------------===//
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bool SVal::hasConjuredSymbol() const {
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if (Optional<nonloc::SymbolVal> SV = getAs<nonloc::SymbolVal>()) {
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SymbolRef sym = SV->getSymbol();
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if (isa<SymbolConjured>(sym))
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return true;
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}
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if (Optional<loc::MemRegionVal> RV = getAs<loc::MemRegionVal>()) {
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const MemRegion *R = RV->getRegion();
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if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
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SymbolRef sym = SR->getSymbol();
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if (isa<SymbolConjured>(sym))
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return true;
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}
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}
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return false;
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}
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const FunctionDecl *SVal::getAsFunctionDecl() const {
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if (Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>()) {
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const MemRegion* R = X->getRegion();
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if (const FunctionTextRegion *CTR = R->getAs<FunctionTextRegion>())
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if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CTR->getDecl()))
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return FD;
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}
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return nullptr;
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}
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/// \brief If this SVal is a location (subclasses Loc) and wraps a symbol,
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/// return that SymbolRef. Otherwise return 0.
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///
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/// Implicit casts (ex: void* -> char*) can turn Symbolic region into Element
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/// region. If that is the case, gets the underlining region.
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/// When IncludeBaseRegions is set to true and the SubRegion is non-symbolic,
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/// the first symbolic parent region is returned.
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SymbolRef SVal::getAsLocSymbol(bool IncludeBaseRegions) const {
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// FIXME: should we consider SymbolRef wrapped in CodeTextRegion?
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if (Optional<nonloc::LocAsInteger> X = getAs<nonloc::LocAsInteger>())
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return X->getLoc().getAsLocSymbol();
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if (Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>()) {
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const MemRegion *R = X->getRegion();
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if (const SymbolicRegion *SymR = IncludeBaseRegions ?
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R->getSymbolicBase() :
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dyn_cast<SymbolicRegion>(R->StripCasts()))
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return SymR->getSymbol();
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}
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return nullptr;
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}
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/// Get the symbol in the SVal or its base region.
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SymbolRef SVal::getLocSymbolInBase() const {
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Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>();
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if (!X)
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return nullptr;
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const MemRegion *R = X->getRegion();
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while (const SubRegion *SR = dyn_cast<SubRegion>(R)) {
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if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(SR))
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return SymR->getSymbol();
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else
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R = SR->getSuperRegion();
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}
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return nullptr;
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}
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// TODO: The next 3 functions have to be simplified.
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/// \brief If this SVal wraps a symbol return that SymbolRef.
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/// Otherwise, return 0.
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///
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/// Casts are ignored during lookup.
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/// \param IncludeBaseRegions The boolean that controls whether the search
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/// should continue to the base regions if the region is not symbolic.
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SymbolRef SVal::getAsSymbol(bool IncludeBaseRegion) const {
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// FIXME: should we consider SymbolRef wrapped in CodeTextRegion?
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if (Optional<nonloc::SymbolVal> X = getAs<nonloc::SymbolVal>())
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return X->getSymbol();
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return getAsLocSymbol(IncludeBaseRegion);
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}
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/// getAsSymbolicExpression - If this Sval wraps a symbolic expression then
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/// return that expression. Otherwise return NULL.
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const SymExpr *SVal::getAsSymbolicExpression() const {
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if (Optional<nonloc::SymbolVal> X = getAs<nonloc::SymbolVal>())
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return X->getSymbol();
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return getAsSymbol();
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}
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const SymExpr* SVal::getAsSymExpr() const {
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const SymExpr* Sym = getAsSymbol();
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if (!Sym)
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Sym = getAsSymbolicExpression();
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return Sym;
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}
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const MemRegion *SVal::getAsRegion() const {
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if (Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>())
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return X->getRegion();
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if (Optional<nonloc::LocAsInteger> X = getAs<nonloc::LocAsInteger>())
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return X->getLoc().getAsRegion();
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return nullptr;
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}
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const MemRegion *loc::MemRegionVal::stripCasts(bool StripBaseCasts) const {
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const MemRegion *R = getRegion();
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return R ? R->StripCasts(StripBaseCasts) : nullptr;
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}
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const void *nonloc::LazyCompoundVal::getStore() const {
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return static_cast<const LazyCompoundValData*>(Data)->getStore();
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}
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const TypedValueRegion *nonloc::LazyCompoundVal::getRegion() const {
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return static_cast<const LazyCompoundValData*>(Data)->getRegion();
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}
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//===----------------------------------------------------------------------===//
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// Other Iterators.
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//===----------------------------------------------------------------------===//
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nonloc::CompoundVal::iterator nonloc::CompoundVal::begin() const {
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return getValue()->begin();
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}
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nonloc::CompoundVal::iterator nonloc::CompoundVal::end() const {
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return getValue()->end();
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}
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//===----------------------------------------------------------------------===//
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// Useful predicates.
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//===----------------------------------------------------------------------===//
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bool SVal::isConstant() const {
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return getAs<nonloc::ConcreteInt>() || getAs<loc::ConcreteInt>();
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}
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bool SVal::isConstant(int I) const {
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if (Optional<loc::ConcreteInt> LV = getAs<loc::ConcreteInt>())
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return LV->getValue() == I;
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if (Optional<nonloc::ConcreteInt> NV = getAs<nonloc::ConcreteInt>())
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return NV->getValue() == I;
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return false;
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}
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bool SVal::isZeroConstant() const {
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return isConstant(0);
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}
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//===----------------------------------------------------------------------===//
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// Transfer function dispatch for Non-Locs.
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//===----------------------------------------------------------------------===//
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SVal nonloc::ConcreteInt::evalBinOp(SValBuilder &svalBuilder,
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BinaryOperator::Opcode Op,
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const nonloc::ConcreteInt& R) const {
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const llvm::APSInt* X =
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svalBuilder.getBasicValueFactory().evalAPSInt(Op, getValue(), R.getValue());
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if (X)
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return nonloc::ConcreteInt(*X);
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else
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return UndefinedVal();
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}
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nonloc::ConcreteInt
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nonloc::ConcreteInt::evalComplement(SValBuilder &svalBuilder) const {
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return svalBuilder.makeIntVal(~getValue());
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}
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nonloc::ConcreteInt
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nonloc::ConcreteInt::evalMinus(SValBuilder &svalBuilder) const {
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return svalBuilder.makeIntVal(-getValue());
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}
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//===----------------------------------------------------------------------===//
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// Transfer function dispatch for Locs.
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//===----------------------------------------------------------------------===//
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SVal loc::ConcreteInt::evalBinOp(BasicValueFactory& BasicVals,
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BinaryOperator::Opcode Op,
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const loc::ConcreteInt& R) const {
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assert(BinaryOperator::isComparisonOp(Op) || Op == BO_Sub);
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const llvm::APSInt *X = BasicVals.evalAPSInt(Op, getValue(), R.getValue());
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if (X)
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return nonloc::ConcreteInt(*X);
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else
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return UndefinedVal();
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}
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//===----------------------------------------------------------------------===//
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// Pretty-Printing.
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//===----------------------------------------------------------------------===//
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void SVal::dump() const { dumpToStream(llvm::errs()); }
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void SVal::dumpToStream(raw_ostream &os) const {
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switch (getBaseKind()) {
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case UnknownKind:
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os << "Unknown";
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break;
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case NonLocKind:
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castAs<NonLoc>().dumpToStream(os);
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break;
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case LocKind:
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castAs<Loc>().dumpToStream(os);
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break;
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case UndefinedKind:
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os << "Undefined";
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break;
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}
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}
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void NonLoc::dumpToStream(raw_ostream &os) const {
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switch (getSubKind()) {
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case nonloc::ConcreteIntKind: {
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const nonloc::ConcreteInt& C = castAs<nonloc::ConcreteInt>();
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if (C.getValue().isUnsigned())
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os << C.getValue().getZExtValue();
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else
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os << C.getValue().getSExtValue();
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os << ' ' << (C.getValue().isUnsigned() ? 'U' : 'S')
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<< C.getValue().getBitWidth() << 'b';
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break;
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}
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case nonloc::SymbolValKind: {
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os << castAs<nonloc::SymbolVal>().getSymbol();
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break;
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}
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case nonloc::LocAsIntegerKind: {
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const nonloc::LocAsInteger& C = castAs<nonloc::LocAsInteger>();
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os << C.getLoc() << " [as " << C.getNumBits() << " bit integer]";
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break;
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}
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case nonloc::CompoundValKind: {
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const nonloc::CompoundVal& C = castAs<nonloc::CompoundVal>();
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os << "compoundVal{";
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bool first = true;
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for (nonloc::CompoundVal::iterator I=C.begin(), E=C.end(); I!=E; ++I) {
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if (first) {
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os << ' '; first = false;
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}
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else
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os << ", ";
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(*I).dumpToStream(os);
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}
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os << "}";
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break;
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}
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case nonloc::LazyCompoundValKind: {
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const nonloc::LazyCompoundVal &C = castAs<nonloc::LazyCompoundVal>();
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os << "lazyCompoundVal{" << const_cast<void *>(C.getStore())
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<< ',' << C.getRegion()
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<< '}';
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break;
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}
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default:
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assert (false && "Pretty-printed not implemented for this NonLoc.");
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break;
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}
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}
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void Loc::dumpToStream(raw_ostream &os) const {
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switch (getSubKind()) {
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case loc::ConcreteIntKind:
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os << castAs<loc::ConcreteInt>().getValue().getZExtValue() << " (Loc)";
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break;
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case loc::GotoLabelKind:
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os << "&&" << castAs<loc::GotoLabel>().getLabel()->getName();
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break;
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case loc::MemRegionKind:
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os << '&' << castAs<loc::MemRegionVal>().getRegion()->getString();
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break;
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default:
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llvm_unreachable("Pretty-printing not implemented for this Loc.");
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}
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}
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