HeaderSearch.h

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//===- HeaderSearch.h - Resolve Header File Locations -----------*- 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 defines the HeaderSearch interface.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_LEX_HEADERSEARCH_H
#define LLVM_CLANG_LEX_HEADERSEARCH_H
 
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/DirectoryLookup.h"
#include "clang/Lex/ExternalPreprocessorSource.h"
#include "clang/Lex/HeaderMap.h"
#include "clang/Lex/ModuleMap.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Support/Allocator.h"
#include <cassert>
#include <cstddef>
#include <memory>
#include <string>
#include <utility>
#include <vector>
 
namespace llvm {
 
class Triple;
 
} // namespace llvm
 
namespace clang {
 
class DiagnosticsEngine;
class DirectoryEntry;
class ExternalPreprocessorSource;
class FileEntry;
class FileManager;
class HeaderSearch;
class HeaderSearchOptions;
class IdentifierInfo;
class LangOptions;
class Module;
class Preprocessor;
class TargetInfo;
 
/// The preprocessor keeps track of this information for each
/// file that is \#included.
struct HeaderFileInfo {
  // TODO: Whether the file was included is not a property of the file itself.
  // It's a preprocessor state, move it there.
  /// True if this file has been included (or imported) **locally**.
  LLVM_PREFERRED_TYPE(bool)
  unsigned IsLocallyIncluded : 1;
 
  // TODO: Whether the file was imported is not a property of the file itself.
  // It's a preprocessor state, move it there.
  /// True if this is a \#import'd file.
  LLVM_PREFERRED_TYPE(bool)
  unsigned isImport : 1;
 
  /// True if this is a \#pragma once file.
  LLVM_PREFERRED_TYPE(bool)
  unsigned isPragmaOnce : 1;
 
  /// Keep track of whether this is a system header, and if so,
  /// whether it is C++ clean or not.  This can be set by the include paths or
  /// by \#pragma gcc system_header.  This is an instance of
  /// SrcMgr::CharacteristicKind.
  LLVM_PREFERRED_TYPE(SrcMgr::CharacteristicKind)
  unsigned DirInfo : 3;
 
  /// Whether this header file info was supplied by an external source,
  /// and has not changed since.
  LLVM_PREFERRED_TYPE(bool)
  unsigned External : 1;
 
  /// Whether this header is part of and built with a module.  i.e. it is listed
  /// in a module map, and is not `excluded` or `textual`. (same meaning as
  /// `ModuleMap::isModular()`).
  LLVM_PREFERRED_TYPE(bool)
  unsigned isModuleHeader : 1;
 
  /// Whether this header is a `textual header` in a module. If a header is
  /// textual in one module and normal in another module, this bit will not be
  /// set, only `isModuleHeader`.
  LLVM_PREFERRED_TYPE(bool)
  unsigned isTextualModuleHeader : 1;
 
  /// Whether this header is part of the module that we are building, even if it
  /// doesn't build with the module. i.e. this will include `excluded` and
  /// `textual` headers as well as normal headers.
  LLVM_PREFERRED_TYPE(bool)
  unsigned isCompilingModuleHeader : 1;
 
  /// Whether this structure is considered to already have been
  /// "resolved", meaning that it was loaded from the external source.
  LLVM_PREFERRED_TYPE(bool)
  unsigned Resolved : 1;
 
  /// Whether this file has been looked up as a header.
  LLVM_PREFERRED_TYPE(bool)
  unsigned IsValid : 1;
 
  /// If this file has a \#ifndef XXX (or equivalent) guard that
  /// protects the entire contents of the file, this is the identifier
  /// for the macro that controls whether or not it has any effect.
  ///
  /// Note: Most clients should use getControllingMacro() to access
  /// the controlling macro of this header, since
  /// getControllingMacro() is able to load a controlling macro from
  /// external storage.
  LazyIdentifierInfoPtr LazyControllingMacro;
 
  HeaderFileInfo()
      : IsLocallyIncluded(false), isImport(false), isPragmaOnce(false),
        DirInfo(SrcMgr::C_User), External(false), isModuleHeader(false),
        isTextualModuleHeader(false), isCompilingModuleHeader(false),
        Resolved(false), IsValid(false) {}
 
  /// Retrieve the controlling macro for this header file, if
  /// any.
  const IdentifierInfo *
  getControllingMacro(ExternalPreprocessorSource *External);
 
  /// Update the module membership bits based on the header role.
  ///
  /// isModuleHeader will potentially be set, but not cleared.
  /// isTextualModuleHeader will be set or cleared based on the role update.
  void mergeModuleMembership(ModuleMap::ModuleHeaderRole Role);
};
 
static_assert(sizeof(HeaderFileInfo) <= 16);