//===- Environment.h - Map from Stmt* to Locations/Values -------*- C++ -*-===//
 
//
 
// 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 defined the Environment and EnvironmentManager classes.
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_ENVIRONMENT_H
 
#define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_ENVIRONMENT_H
 
 
 
#include "clang/Analysis/AnalysisDeclContext.h"
 
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
 
#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
 
#include "llvm/ADT/ImmutableMap.h"
 
#include <utility>
 
 
 
namespace clang {
 
 
 
class Stmt;
 
 
 
namespace ento {
 
 
 
class SValBuilder;
 
class SymbolReaper;
 
 
 
/// An entry in the environment consists of a Stmt and an LocationContext.
 
/// This allows the environment to manage context-sensitive bindings,
 
/// which is essentially for modeling recursive function analysis, among
 
/// other things.
 
class EnvironmentEntry : public std::pair<const Stmt *,
 
                                          const StackFrameContext *> {
 
public:
 
  EnvironmentEntry(const Stmt *s, const LocationContext *L);
 
 
 
  const Stmt *getStmt() const { return first; }
 
  const LocationContext *getLocationContext() const { return second; }
 
 
 
  /// Profile an EnvironmentEntry for inclusion in a FoldingSet.
 
  static void Profile(llvm::FoldingSetNodeID &ID,
 
                      const EnvironmentEntry &E) {
 
    ID.AddPointer(E.getStmt());
 
    ID.AddPointer(E.getLocationContext());
 
  }
 
 
 
  void Profile(llvm::FoldingSetNodeID &ID) const {
 
    Profile(ID, *this);
 
  }
 
};
 
 
 
/// An immutable map from EnvironemntEntries to SVals.
 
class Environment {
 
private:
 
  friend class EnvironmentManager;
 
 
 
  using BindingsTy = llvm::ImmutableMap<EnvironmentEntry, SVal>;
 
 
 
  BindingsTy ExprBindings;
 
 
 
  Environment(BindingsTy eb) : ExprBindings(eb) {}
 
 
 
  SVal lookupExpr(const EnvironmentEntry &E) const;
 
 
 
public:
 
  using iterator = BindingsTy::iterator;
 
 
 
  iterator begin() const { return ExprBindings.begin(); }
 
  iterator end() const { return ExprBindings.end(); }
 
 
 
  /// Fetches the current binding of the expression in the
 
  /// Environment.
 
  SVal getSVal(const EnvironmentEntry &E, SValBuilder &svalBuilder) const;
 
 
 
  /// Profile - Profile the contents of an Environment object for use
 
  ///  in a FoldingSet.
 
  static void Profile(llvm::FoldingSetNodeID& ID, const Environment* env) {
 
    env->ExprBindings.Profile(ID);
 
  }
 
 
 
  /// Profile - Used to profile the contents of this object for inclusion
 
  ///  in a FoldingSet.
 
  void Profile(llvm::FoldingSetNodeID& ID) const {
 
    Profile(ID, this);
 
  }
 
 
 
  bool operator==(const Environment& RHS) const {
 
    return ExprBindings == RHS.ExprBindings;
 
  }
 
 
 
  void printJson(raw_ostream &Out, const ASTContext &Ctx,
 
                 const LocationContext *LCtx = nullptr, const char *NL = "\n",
 
                 unsigned int Space = 0, bool IsDot = false) const;
 
};
 
 
 
class EnvironmentManager {
 
private:
 
  using FactoryTy = Environment::BindingsTy::Factory;
 
 
 
  FactoryTy F;
 
 
 
public:
 
  EnvironmentManager(llvm::BumpPtrAllocator &Allocator) : F(Allocator) {}
 
 
 
  Environment getInitialEnvironment() {
 
    return Environment(F.getEmptyMap());
 
  }
 
 
 
  /// Bind a symbolic value to the given environment entry.
 
  Environment bindExpr(Environment Env, const EnvironmentEntry &E, SVal V,
 
                       bool Invalidate);
 
 
 
  Environment removeDeadBindings(Environment Env,
 
                                 SymbolReaper &SymReaper,
 
                                 ProgramStateRef state);
 
};
 
 
 
} // namespace ento
 
 
 
} // namespace clang
 
 
 
#endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_ENVIRONMENT_H