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-rw-r--r--lib/Checker/SVals.cpp327
1 files changed, 327 insertions, 0 deletions
diff --git a/lib/Checker/SVals.cpp b/lib/Checker/SVals.cpp
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+++ b/lib/Checker/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/Checker/PathSensitive/GRState.h"
+#include "clang/Basic/IdentifierTable.h"
+
+using namespace clang;
+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 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;
+}
+
+/// 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::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(ValueManager &ValMgr,
+ BinaryOperator::Opcode Op,
+ const nonloc::ConcreteInt& R) const {
+ const llvm::APSInt* X =
+ ValMgr.getBasicValueFactory().EvaluateAPSInt(Op, getValue(), R.getValue());
+
+ if (X)
+ return nonloc::ConcreteInt(*X);
+ else
+ return UndefinedVal();
+}
+
+nonloc::ConcreteInt
+nonloc::ConcreteInt::evalComplement(ValueManager &ValMgr) const {
+ return ValMgr.makeIntVal(~getValue());
+}
+
+nonloc::ConcreteInt nonloc::ConcreteInt::evalMinus(ValueManager &ValMgr) const {
+ return ValMgr.makeIntVal(-getValue());
+}
+
+//===----------------------------------------------------------------------===//
+// Transfer function dispatch for Locs.
+//===----------------------------------------------------------------------===//
+
+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();
+}
+
+//===----------------------------------------------------------------------===//
+// Pretty-Printing.
+//===----------------------------------------------------------------------===//
+
+void SVal::dump() const { dumpToStream(llvm::errs()); }
+
+void SVal::dumpToStream(llvm::raw_ostream& os) const {
+ switch (getBaseKind()) {
+ case UnknownKind:
+ os << "Invalid";
+ 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:
+ os << cast<nonloc::ConcreteInt>(this)->getValue().getZExtValue();
+ if (cast<nonloc::ConcreteInt>(this)->getValue().isUnsigned())
+ os << 'U';
+ 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{" << (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;
+ }
+}
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