CodeGenTBAA.h

Go to the documentation of this file.

//===--- CodeGenTBAA.h - TBAA information for LLVM CodeGen ------*- 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 is the code that manages TBAA information and defines the TBAA policy
// for the optimizer to use.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENTBAA_H
#define LLVM_CLANG_LIB_CODEGEN_CODEGENTBAA_H
 
#include "clang/AST/Type.h"
#include "clang/Basic/LLVM.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Metadata.h"
 
namespace clang {
  class ASTContext;
  class CodeGenOptions;
  class LangOptions;
  class MangleContext;
  class QualType;
  class Type;
 
namespace CodeGen {
class CodeGenTypes;
 
// TBAAAccessKind - A kind of TBAA memory access descriptor.
enum class TBAAAccessKind : unsigned {
  Ordinary,
  MayAlias,
  Incomplete,
};
 
// TBAAAccessInfo - Describes a memory access in terms of TBAA.
struct TBAAAccessInfo {
  TBAAAccessInfo(TBAAAccessKind Kind, llvm::MDNode *BaseType,
                 llvm::MDNode *AccessType, uint64_t Offset, uint64_t Size)
    : Kind(Kind), BaseType(BaseType), AccessType(AccessType),
      Offset(Offset), Size(Size)
  {}
 
  TBAAAccessInfo(llvm::MDNode *BaseType, llvm::MDNode *AccessType,
                 uint64_t Offset, uint64_t Size)
    : TBAAAccessInfo(TBAAAccessKind::Ordinary, BaseType, AccessType,
                     Offset, Size)
  {}
 
  explicit TBAAAccessInfo(llvm::MDNode *AccessType, uint64_t Size)
    : TBAAAccessInfo(/* BaseType= */ nullptr, AccessType, /* Offset= */ 0, Size)
  {}
 
  TBAAAccessInfo()
    : TBAAAccessInfo(/* AccessType= */ nullptr, /* Size= */ 0)
  {}
 
  static TBAAAccessInfo getMayAliasInfo() {
    return TBAAAccessInfo(TBAAAccessKind::MayAlias,
                          /* BaseType= */ nullptr, /* AccessType= */ nullptr,
                          /* Offset= */ 0, /* Size= */ 0);
  }
 
  bool isMayAlias() const { return Kind == TBAAAccessKind::MayAlias; }
 
  static TBAAAccessInfo getIncompleteInfo() {
    return TBAAAccessInfo(TBAAAccessKind::Incomplete,
                          /* BaseType= */ nullptr, /* AccessType= */ nullptr,
                          /* Offset= */ 0, /* Size= */ 0);
  }
 
  bool isIncomplete() const { return Kind == TBAAAccessKind::Incomplete; }
 
  bool operator==(const TBAAAccessInfo &Other) const {
    return Kind == Other.Kind &&