SymbolManager.cpp

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//===- SymbolManager.h - Management of Symbolic Values --------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//  This file defines SymbolManager, a class that manages symbolic values
//  created for use by ExprEngine and related classes.
//
//===----------------------------------------------------------------------===//
 
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Expr.h"
#include "clang/AST/StmtObjC.h"
#include "clang/Analysis/Analyses/LiveVariables.h"
#include "clang/Analysis/AnalysisDeclContext.h"
#include "clang/Basic/LLVM.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SymExpr.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
 
using namespace clang;
using namespace ento;
 
void SymExpr::anchor() {}
 
StringRef SymbolConjured::getKindStr() const { return "conj_$"; }
StringRef SymbolDerived::getKindStr() const { return "derived_$"; }
StringRef SymbolExtent::getKindStr() const { return "extent_$"; }
StringRef SymbolMetadata::getKindStr() const { return "meta_$"; }
StringRef SymbolRegionValue::getKindStr() const { return "reg_$"; }
 
LLVM_DUMP_METHOD void SymExpr::dump() const { dumpToStream(llvm::errs()); }
 
void BinarySymExpr::dumpToStreamImpl(raw_ostream &OS, const SymExpr *Sym) {
  OS << '(';
  Sym->dumpToStream(OS);
  OS << ')';
}
 
void BinarySymExpr::dumpToStreamImpl(raw_ostream &OS,
                                     const llvm::APSInt &Value) {
  if (Value.isUnsigned())
    OS << Value.getZExtValue();
  else
    OS << Value.getSExtValue();
  if (Value.isUnsigned())
    OS << 'U';
}
 
void BinarySymExpr::dumpToStreamImpl(raw_ostream &OS,
                                     BinaryOperator::Opcode Op) {
  OS << ' ' << BinaryOperator::getOpcodeStr(Op) << ' ';
}
 
void SymbolCast::dumpToStream(raw_ostream &os) const {
  os << '(' << ToTy << ") (";
  Operand->dumpToStream(os);
  os << ')';
}
 
void UnarySymExpr::dumpToStream(raw_ostream &os) const {
  os << UnaryOperator::getOpcodeStr(Op);
  bool Binary = isa<BinarySymExpr>(Operand);
  if (Binary)
    os << '(';
  Operand->dumpToStream(os);
  if (Binary)
    os << ')';
}
 
void SymbolConjured::dumpToStream(raw_ostream &os) const {
  os << getKindStr() << getSymbolID() << '{' << T << ", LC" << LCtx->getID();
  if (S)
    os << ", S" << S->getID(LCtx->getDecl()->getASTContext());
  else
    os << ", no stmt";
  os << ", #" << Count << '}';
}
 
void SymbolDerived::dumpToStream(raw_ostream &os) const {
  os << getKindStr() << getSymbolID() << '{' << getParentSymbol() << ','
     << getRegion() << '}';
}
 
void SymbolExtent::dumpToStream(raw_ostream &os) const {
  os << getKindStr() << getSymbolID() << '{' << getRegion() << '}';
}
 
void SymbolMetadata::dumpToStream(raw_ostream &os) const {
  os << getKindStr() << getSymbolID() << '{' << getRegion() << ',' << T << '}';
}
 
void SymbolData::anchor() {}
 
void SymbolRegionValue::dumpToStream(raw_ostream &os) const {
  os << getKindStr() << getSymbolID() << '<' << getType() << ' ' << R << '>';
}
 
bool SymExpr::symbol_iterator::operator==(const symbol_iterator &X) const {
  return itr == X.itr;
}
 
bool SymExpr::symbol_iterator::operator!=(const symbol_iterator &X) const {
  return itr != X.itr;
}
 
SymExpr::symbol_iterator::symbol_iterator(const SymExpr *SE) {
  itr.push_back(SE);
}
 
SymExpr::symbol_iterator &SymExpr::symbol_iterator::operator++() {
  assert(!itr.empty() && "attempting to iterate on an 'end' iterator");
  expand();
  return *this;
}
 
SymbolRef SymExpr::symbol_iterator::operator*() {
  assert(!itr.empty() && "attempting to dereference an 'end' iterator");
  return itr.back();
}
 
void SymExpr::symbol_iterator::expand() {
  const SymExpr *SE = itr.pop_back_val();
 
  switch (SE->getKind()) {
    case SymExpr::SymbolRegionValueKind:
    case SymExpr::SymbolConjuredKind:
    case SymExpr::SymbolDerivedKind:
    case SymExpr::SymbolExtentKind:
    case SymExpr::SymbolMetadataKind:
      return;
    case SymExpr::SymbolCastKind:
      itr.push_back(cast<SymbolCast>(SE)->getOperand());
      return;
    case SymExpr::UnarySymExprKind:
      itr.push_back(cast<UnarySymExpr>(SE)->getOperand());
      return;
    case SymExpr::SymIntExprKind:
      itr.push_back(cast<SymIntExpr>(SE)->getLHS());
      return;
    case SymExpr::IntSymExprKind:
      itr.push_back(cast<IntSymExpr>(SE)->getRHS());
      return;
    case SymExpr::SymSymExprKind: {
      const auto *x = cast<SymSymExpr>(SE);
      itr.push_back(x->getLHS());
      itr.push_back(x->getRHS());
      return;
    }
  }
  llvm_unreachable("unhandled expansion case");
}
 
QualType SymbolConjured::getType() const {
  return T;
}
 
QualType SymbolDerived::getType() const {
  return R->getValueType();
}
 
QualType SymbolExtent::getType() const {
  ASTContext &Ctx = R->getMemRegionManager().getContext();
  return Ctx.getSizeType();
}
 
QualType SymbolMetadata::getType() const {
  return T;
}