path: root/include/clang/Analysis/CFG.h

//===--- CFG.h - Classes for representing and building CFGs------*- 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 the CFG and CFGBuilder classes for representing and
//  building Control-Flow Graphs (CFGs) from ASTs.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_CFG_H
#define LLVM_CLANG_CFG_H

#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/GraphTraits.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Casting.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/DenseMap.h"
#include "clang/AST/Stmt.h"
#include "clang/Analysis/Support/BumpVector.h"
#include "clang/Basic/SourceLocation.h"
#include <bitset>
#include <cassert>
#include <iterator>

namespace clang {
  class CXXDestructorDecl;
  class Decl;
  class Stmt;
  class Expr;
  class FieldDecl;
  class VarDecl;
  class CXXCtorInitializer;
  class CXXBaseSpecifier;
  class CXXBindTemporaryExpr;
  class CFG;
  class PrinterHelper;
  class LangOptions;
  class ASTContext;

/// CFGElement - Represents a top-level expression in a basic block.
class CFGElement {
public:
  enum Kind {
    // main kind
    Invalid,
    Statement,
    Initializer,
    // dtor kind
    AutomaticObjectDtor,
    BaseDtor,
    MemberDtor,
    TemporaryDtor,
    DTOR_BEGIN = AutomaticObjectDtor,
    DTOR_END = TemporaryDtor
  };

protected:
  // The int bits are used to mark the kind.
  llvm::PointerIntPair<void *, 2> Data1;
  llvm::PointerIntPair<void *, 2> Data2;

  CFGElement(Kind kind, const void *Ptr1, const void *Ptr2 = 0)
    : Data1(const_cast<void*>(Ptr1), ((unsigned) kind) & 0x3),
      Data2(const_cast<void*>(Ptr2), (((unsigned) kind) >> 2) & 0x3) {}

public:
  CFGElement() {}

  Kind getKind() const {
    unsigned x = Data2.getInt();
    x <<= 2;
    x |= Data1.getInt();
    return (Kind) x;
  }

  bool isValid() const { return getKind() != Invalid; }

  operator bool() const { return isValid(); }

  template<class ElemTy> const ElemTy *getAs() const {
    if (llvm::isa<ElemTy>(this))
      return static_cast<const ElemTy*>(this);
    return 0;
  }

  static bool classof(const CFGElement *E) { return true; }
};

class CFGStmt : public CFGElement {
public:
  CFGStmt(Stmt *S) : CFGElement(Statement, S) {}

  const Stmt *getStmt() const {
    return static_cast<const Stmt *>(Data1.getPointer());
  }

  static bool classof(const CFGElement *E) {
    return E->getKind() == Statement;
  }
};

/// CFGInitializer - Represents C++ base or member initializer from
/// constructor's initialization list.
class CFGInitializer : public CFGElement {
public:
  CFGInitializer(CXXCtorInitializer *initializer)
      : CFGElement(Initializer, initializer) {}

  CXXCtorInitializer* getInitializer() const {
    return static_cast<CXXCtorInitializer*>(Data1.getPointer());
  }

  static bool classof(const CFGElement *E) {
    return E->getKind() == Initializer;
  }
};

/// CFGImplicitDtor - Represents C++ object destructor implicitly generated
/// by compiler on various occasions.
class CFGImplicitDtor : public CFGElement {
protected:
  CFGImplicitDtor(Kind kind, const void *data1, const void *data2 = 0)
    : CFGElement(kind, data1, data2) {
    assert(kind >= DTOR_BEGIN && kind <= DTOR_END);
  }

public:
  const CXXDestructorDecl *getDestructorDecl(ASTContext &astContext) const;
  bool isNoReturn(ASTContext &astContext) const;

  static bool classof(const CFGElement *E) {
    Kind kind = E->getKind();
    return kind >= DTOR_BEGIN && kind <= DTOR_END;
  }
};

/// CFGAutomaticObjDtor - Represents C++ object destructor implicitly generated
/// for automatic object or temporary bound to const reference at the point
/// of leaving its local scope.
class CFGAutomaticObjDtor: public CFGImplicitDtor {
public:
  CFGAutomaticObjDtor(const VarDecl *var, const Stmt *stmt)
      : CFGImplicitDtor(AutomaticObjectDtor, var, stmt) {}

  const VarDecl *getVarDecl() const {
    return static_cast<VarDecl*>(Data1.getPointer());
  }

  // Get statement end of which triggered the destructor call.
  const Stmt *getTriggerStmt() const {
    return static_cast<Stmt*>(D