PtrTypesSemantics.h

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//=======- PtrTypesSemantics.cpp ---------------------------------*- 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
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_ANALYZER_WEBKIT_PTRTYPESEMANTICS_H
#define LLVM_CLANG_ANALYZER_WEBKIT_PTRTYPESEMANTICS_H
 
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/PointerUnion.h"
#include <optional>
 
namespace clang {
class CXXBaseSpecifier;
class CXXMethodDecl;
class CXXRecordDecl;
class Decl;
class FunctionDecl;
class Stmt;
class Type;
 
// Ref-countability of a type is implicitly defined by Ref<T> and RefPtr<T>
// implementation. It can be modeled as: type T having public methods ref() and
// deref()
 
// In WebKit there are two ref-counted templated smart pointers: RefPtr<T> and
// Ref<T>.
 
/// \returns CXXRecordDecl of the base if the type has ref as a public method,
/// nullptr if not, std::nullopt if inconclusive.
std::optional<const clang::CXXRecordDecl *>
hasPublicMethodInBase(const CXXBaseSpecifier *Base, const char *NameToMatch);
 
/// \returns true if \p Class is ref-countable, false if not, std::nullopt if
/// inconclusive.
std::optional<bool> isRefCountable(const clang::CXXRecordDecl* Class);
 
/// \returns true if \p Class is ref-counted, false if not.
bool isRefCounted(const clang::CXXRecordDecl *Class);
 
/// \returns true if \p Class is ref-countable AND not ref-counted, false if
/// not, std::nullopt if inconclusive.
std::optional<bool> isUncounted(const clang::CXXRecordDecl* Class);
 
/// \returns true if \p T is either a raw pointer or reference to an uncounted
/// class, false if not, std::nullopt if inconclusive.
std::optional<bool> isUncountedPtr(const clang::Type* T);
 
/// \returns true if \p F creates ref-countable object from uncounted parameter,
/// false if not.
bool isCtorOfRefCounted(const clang::FunctionDecl *F);
 
/// \returns true if \p F returns a ref-counted object, false if not.
bool isReturnValueRefCounted(const clang::FunctionDecl *F);
 
/// \returns true if \p M is getter of a ref-counted class, false if not.
std::optional<bool> isGetterOfRefCounted(const clang::CXXMethodDecl* Method);
 
/// \returns true if \p F is a conversion between ref-countable or ref-counted
/// pointer types.
bool isPtrConversion(const FunctionDecl *F);
 
/// \returns true if \p F is a static singleton function.
bool isSingleton(const FunctionDecl *F);
 
/// An inter-procedural analysis facility that detects functions with "trivial"
/// behavior with respect to reference counting, such as simple field getters.
class TrivialFunctionAnalysis {
public:
  /// \returns true if \p D is a "trivial" function.
  bool isTrivial(const Decl *D) const { return isTrivialImpl(D, TheCache); }
  bool isTrivial(const Stmt *S) const { return isTrivialImpl(S, TheCache); }
 
private:
  friend class TrivialFunctionAnalysisVisitor;
 
  using CacheTy =
      llvm::DenseMap<llvm::PointerUnion<const Decl *, const Stmt *>, bool>;
  mutable CacheTy TheCache{};
 
  static bool isTrivialImpl(const Decl *D, CacheTy &Cache);
  static bool isTrivialImpl(const Stmt *S, CacheTy &Cache);
};
 
} // namespace clang
 
#endif