path: root/lib/Analysis/MemRegion.cpp

//== MemRegion.cpp - Abstract memory regions for static analysis --*- 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 MemRegion and its subclasses.  MemRegion defines a
//  partially-typed abstraction of memory useful for path-sensitive dataflow
//  analyses.
//
//===----------------------------------------------------------------------===//

#include "llvm/Support/raw_ostream.h"
#include "clang/Analysis/PathSensitive/MemRegion.h"

using namespace clang;


MemRegion::~MemRegion() {}

void MemSpaceRegion::Profile(llvm::FoldingSetNodeID& ID) const {
  ID.AddInteger((unsigned)getKind());
}

void StringRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, 
                                 const StringLiteral* Str, 
                                 const MemRegion* superRegion) {
  ID.AddInteger((unsigned) StringRegionKind);
  ID.AddPointer(Str);
  ID.AddPointer(superRegion);
}

void AllocaRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
                                 const Expr* Ex, unsigned cnt) {
  ID.AddInteger((unsigned) AllocaRegionKind);
  ID.AddPointer(Ex);
  ID.AddInteger(cnt);
}

void AllocaRegion::Profile(llvm::FoldingSetNodeID& ID) const {
  ProfileRegion(ID, Ex, Cnt);
}

void AnonTypedRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, QualType T, 
                                    const MemRegion* superRegion) {
  ID.AddInteger((unsigned) AnonTypedRegionKind);
  ID.Add(T);
  ID.AddPointer(superRegion);
}

void CompoundLiteralRegion::Profile(llvm::FoldingSetNodeID& ID) const {
  CompoundLiteralRegion::ProfileRegion(ID, CL, superRegion);
}

void CompoundLiteralRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
                                          const CompoundLiteralExpr* CL,
                                          const MemRegion* superRegion) {
  ID.AddInteger((unsigned) CompoundLiteralRegionKind);
  ID.AddPointer(CL);
  ID.AddPointer(superRegion);
}

void DeclRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, const Decl* D,
                               const MemRegion* superRegion, Kind k) {
  ID.AddInteger((unsigned) k);
  ID.AddPointer(D);
  ID.AddPointer(superRegion);
}

void DeclRegion::Profile(llvm::FoldingSetNodeID& ID) const {
  DeclRegion::ProfileRegion(ID, D, superRegion, getKind());
}

void SymbolicRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, SymbolRef sym) {
  ID.AddInteger((unsigned) MemRegion::SymbolicRegionKind);
  ID.Add(sym);
}

void SymbolicRegion::Profile(llvm::FoldingSetNodeID& ID) const {
  SymbolicRegion::ProfileRegion(ID, sym);
}

void ElementRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, SVal Idx, 
                                  const MemRegion* superRegion) {
  ID.AddInteger(MemRegion::ElementRegionKind);
  ID.AddPointer(superRegion);
  Idx.Profile(ID);
}

void ElementRegion::Profile(llvm::FoldingSetNodeID& ID) const {
  ElementRegion::ProfileRegion(ID, Index, superRegion);
}

QualType ElementRegion::getRValueType(ASTContext& C) const {
  QualType T = getArrayRegion()->getLValueType(C);
  // FIXME: Should ArrayType be considered an LValue or RValue type?
  if (isa<ArrayType>(T.getTypePtr())) {
    ArrayType* AT = cast<ArrayType>(T.getTypePtr());
    return AT->getElementType();
  }
  else {
    PointerType* PtrT = cast<PointerType>(T.getTypePtr());
    QualType PTy = PtrT->getPointeeType();
    return C.getCanonicalType(PTy);
  }
}

//===----------------------------------------------------------------------===//
// getLValueType() and getRValueType()
//===----------------------------------------------------------------------===//

QualType StringRegion::getRValueType(ASTContext& C) const {
  return Str->getType();
}

//===----------------------------------------------------------------------===//
// Region pretty-printing.
//===----------------------------------------------------------------------===//

std::string MemRegion::getString() const {
  std::string s;
  llvm::raw_string_ostream os(s);
  print(os);
  return os.str();
}

void MemRegion::print(llvm::raw_ostream& os) const {
  os << "<Unknown Region>";
}

void AllocaRegion::print(llvm::raw_ostream& os) const {
  os << "alloca{" << (void*) Ex << ',' << Cnt << '}';
}

void AnonTypedRegion::print(llvm::raw_ostream& os) const {
  os << "anon_type{" << T.getAsString() << ',';
  getSuperRegion()->print(os);
  os << '}';
}

void VarRegion::print(llvm::raw_ostream& os) const {
  os << cast<VarDecl>(D)->getNameAsString();
}

void SymbolicRegion::print(llvm::raw_ostream& os) const {
  os << "SymRegion-";
  sym.print(os);
}

void FieldRegion::print(llvm::raw_ostream& os) const {
  superRegion->print(os);
  os << "->" << getDecl()->getNameAsString();
}

void ElementRegion::print(llvm::raw_ostream& os) const {
  superRegion->print(os);
  os << '['; Index.print(os); os << ']';
}

void CompoundLiteralRegion::print(llvm::raw_ostream& os) const {
  // FIXME: More elaborate pretty-printing.
  os << "{ " << (void*) CL <<  " }";
}

void StringRegion::print(llvm::raw_ostream& os) const {
  if (Str->isWide()) os << 'L';
  os << '"';

  // FIXME: this doesn't print wstrings right.
  for (unsigned i = 0, e = Str->getByteLength(); i != e; ++i) {
    switch (Str->getStrData()[i]) {
    default: os << Str->getStrData()[i]; break;
    // Handle some common ones to make dumps prettier.
    case '\\': os << "\\\\"; break;
    case '"': os << "\\\""; break;
    case '\n': os << "\\n"; break;
    case '\t': os << "\\t"; break;
    case '\a': os << "\\a"; break;
    case '\b': os << "\\b"; break;
    }
  }
  os << '"';
}

//===----------------------------------------------------------------------===//
// MemRegionManager methods.
//===----------------------------------------------------------------------===//
  
MemSpaceRegion* MemRegionManager::LazyAllocate(MemSpaceRegion*& region) {
  
  if (!region) {  
    region = (MemSpaceRegion*) A.Allocate<MemSpaceRegion>();
    new (region) MemSpaceRegion();
  }
  
  return region;
}

MemSpaceRegion* MemRegionManager::getStackRegion() {
  return LazyAllocate(stack);
}

MemSpaceRegion* MemRegionManager::getGlobalsRegion() {
  return LazyAllocate(globals);
}

MemSpaceRegion* MemRegionManager::getHeapRegion() {
  return LazyAllocate(heap);
}

MemSpaceRegion* MemRegionManager::getUnknownRegion() {
  return LazyAllocate(unknown);
}

StringRegion* MemRegionManager::getStringRegion(const StringLiteral* Str) {
  llvm::FoldingSetNodeID ID;
  MemSpaceRegion* GlobalsR = getGlobalsRegion();

  StringRegion::ProfileRegion(ID, Str, GlobalsR);

  void* InsertPos;
  MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
  StringRegion* R = cast_or_null<StringRegion>