forked from OSchip/llvm-project
315 lines
9.7 KiB
C++
315 lines
9.7 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/Analysis/PathSensitive/GRState.h"
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#include "clang/Basic/IdentifierTable.h"
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#include "llvm/Support/Streams.h"
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using namespace clang;
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using llvm::dyn_cast;
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using llvm::cast;
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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 (const nonloc::SymbolVal* SV = dyn_cast<nonloc::SymbolVal>(this)) {
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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 (const loc::MemRegionVal *RV = dyn_cast<loc::MemRegionVal>(this)) {
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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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} else if (const CodeTextRegion *CTR = dyn_cast<CodeTextRegion>(R)) {
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if (CTR->isSymbolic()) {
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SymbolRef sym = CTR->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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}
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return false;
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}
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const FunctionDecl* SVal::getAsFunctionDecl() const {
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if (const loc::MemRegionVal* X = dyn_cast<loc::MemRegionVal>(this)) {
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const MemRegion* R = X->getRegion();
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if (const CodeTextRegion* CTR = R->getAs<CodeTextRegion>()) {
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if (CTR->isDeclared())
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return CTR->getDecl();
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}
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}
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return 0;
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}
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/// getAsLocSymbol - If this SVal is a location (subclasses Loc) and
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/// wraps a symbol, return that SymbolRef. Otherwise return 0.
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// FIXME: should we consider SymbolRef wrapped in CodeTextRegion?
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SymbolRef SVal::getAsLocSymbol() const {
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if (const loc::MemRegionVal *X = dyn_cast<loc::MemRegionVal>(this)) {
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const MemRegion *R = X->getBaseRegion();
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if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(R))
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return SymR->getSymbol();
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}
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return NULL;
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}
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/// getAsSymbol - If this Sval wraps a symbol return that SymbolRef.
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/// Otherwise return 0.
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// FIXME: should we consider SymbolRef wrapped in CodeTextRegion?
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SymbolRef SVal::getAsSymbol() const {
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if (const nonloc::SymbolVal *X = dyn_cast<nonloc::SymbolVal>(this))
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return X->getSymbol();
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if (const nonloc::SymExprVal *X = dyn_cast<nonloc::SymExprVal>(this))
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if (SymbolRef Y = dyn_cast<SymbolData>(X->getSymbolicExpression()))
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return Y;
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return getAsLocSymbol();
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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 (const nonloc::SymExprVal *X = dyn_cast<nonloc::SymExprVal>(this))
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return X->getSymbolicExpression();
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return getAsSymbol();
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}
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const MemRegion *SVal::getAsRegion() const {
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if (const loc::MemRegionVal *X = dyn_cast<loc::MemRegionVal>(this))
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return X->getRegion();
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return 0;
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}
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const MemRegion *loc::MemRegionVal::getBaseRegion() const {
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const MemRegion *R = getRegion();
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return R ? R->getBaseRegion() : NULL;
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}
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bool SVal::symbol_iterator::operator==(const symbol_iterator &X) const {
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return itr == X.itr;
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}
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bool SVal::symbol_iterator::operator!=(const symbol_iterator &X) const {
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return itr != X.itr;
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}
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SVal::symbol_iterator::symbol_iterator(const SymExpr *SE) {
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itr.push_back(SE);
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while (!isa<SymbolData>(itr.back())) expand();
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}
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SVal::symbol_iterator& SVal::symbol_iterator::operator++() {
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assert(!itr.empty() && "attempting to iterate on an 'end' iterator");
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assert(isa<SymbolData>(itr.back()));
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itr.pop_back();
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if (!itr.empty())
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while (!isa<SymbolData>(itr.back())) expand();
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return *this;
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}
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SymbolRef SVal::symbol_iterator::operator*() {
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assert(!itr.empty() && "attempting to dereference an 'end' iterator");
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return cast<SymbolData>(itr.back());
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}
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void SVal::symbol_iterator::expand() {
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const SymExpr *SE = itr.back();
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itr.pop_back();
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if (const SymIntExpr *SIE = dyn_cast<SymIntExpr>(SE)) {
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itr.push_back(SIE->getLHS());
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return;
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}
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else if (const SymSymExpr *SSE = dyn_cast<SymSymExpr>(SE)) {
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itr.push_back(SSE->getLHS());
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itr.push_back(SSE->getRHS());
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return;
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}
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assert(false && "unhandled expansion case");
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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::isZeroConstant() const {
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if (isa<loc::ConcreteInt>(*this))
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return cast<loc::ConcreteInt>(*this).getValue() == 0;
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else if (isa<nonloc::ConcreteInt>(*this))
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return cast<nonloc::ConcreteInt>(*this).getValue() == 0;
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else
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return false;
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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(ValueManager &ValMgr,
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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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ValMgr.getBasicValueFactory().EvaluateAPSInt(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(ValueManager &ValMgr) const {
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return ValMgr.makeIntVal(~getValue());
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}
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nonloc::ConcreteInt nonloc::ConcreteInt::evalMinus(ValueManager &ValMgr) const {
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return ValMgr.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 (Op == BinaryOperator::Add || Op == BinaryOperator::Sub ||
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(Op >= BinaryOperator::LT && Op <= BinaryOperator::NE));
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const llvm::APSInt* X = BasicVals.EvaluateAPSInt(Op, getValue(), R.getValue());
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if (X)
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return loc::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(llvm::raw_ostream& os) const {
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switch (getBaseKind()) {
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case UnknownKind:
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os << "Invalid";
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break;
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case NonLocKind:
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cast<NonLoc>(this)->dumpToStream(os);
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break;
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case LocKind:
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cast<Loc>(this)->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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default:
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assert (false && "Invalid SVal.");
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}
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}
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void NonLoc::dumpToStream(llvm::raw_ostream& os) const {
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switch (getSubKind()) {
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case nonloc::ConcreteIntKind:
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os << cast<nonloc::ConcreteInt>(this)->getValue().getZExtValue();
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if (cast<nonloc::ConcreteInt>(this)->getValue().isUnsigned())
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os << 'U';
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break;
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case nonloc::SymbolValKind:
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os << '$' << cast<nonloc::SymbolVal>(this)->getSymbol();
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break;
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case nonloc::SymExprValKind: {
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const nonloc::SymExprVal& C = *cast<nonloc::SymExprVal>(this);
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const SymExpr *SE = C.getSymbolicExpression();
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os << SE;
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break;
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}
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case nonloc::LocAsIntegerKind: {
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const nonloc::LocAsInteger& C = *cast<nonloc::LocAsInteger>(this);
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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 = *cast<nonloc::CompoundVal>(this);
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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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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(llvm::raw_ostream& os) const {
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switch (getSubKind()) {
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case loc::ConcreteIntKind:
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os << cast<loc::ConcreteInt>(this)->getValue().getZExtValue() << " (Loc)";
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break;
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case loc::GotoLabelKind:
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os << "&&" << cast<loc::GotoLabel>(this)->getLabel()->getID()->getName();
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break;
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case loc::MemRegionKind:
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os << '&' << cast<loc::MemRegionVal>(this)->getRegion()->getString();
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break;
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default:
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assert(false && "Pretty-printing not implemented for this Loc.");
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break;
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}
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}
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