llvm/clang/lib/Lex/HeaderMap.cpp

//===--- HeaderMap.cpp - A file that acts like dir of symlinks ------------===//
//
// 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 implements the HeaderMap interface.
//
//===----------------------------------------------------------------------===//

#include "clang/Lex/HeaderMap.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/FileManager.h"
#include "clang/Lex/HeaderMapTypes.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SwapByteOrder.h"
#include "llvm/Support/SystemZ/zOSSupport.h"
#include <cstring>
#include <memory>
#include <optional>
usingnamespaceclang;

/// HashHMapKey - This is the 'well known' hash function required by the file
/// format, used to look up keys in the hash table.  The hash table uses simple
/// linear probing based on this function.
static inline unsigned HashHMapKey(StringRef Str) { … }



//===----------------------------------------------------------------------===//
// Verification and Construction
//===----------------------------------------------------------------------===//

/// HeaderMap::Create - This attempts to load the specified file as a header
/// map.  If it doesn't look like a HeaderMap, it gives up and returns null.
/// If it looks like a HeaderMap but is obviously corrupted, it puts a reason
/// into the string error argument and returns null.
std::unique_ptr<HeaderMap> HeaderMap::Create(FileEntryRef FE, FileManager &FM) { … }

bool HeaderMapImpl::checkHeader(const llvm::MemoryBuffer &File,
                                bool &NeedsByteSwap) { … }

//===----------------------------------------------------------------------===//
//  Utility Methods
//===----------------------------------------------------------------------===//


/// getFileName - Return the filename of the headermap.
StringRef HeaderMapImpl::getFileName() const { … }

unsigned HeaderMapImpl::getEndianAdjustedWord(unsigned X) const { … }

/// getHeader - Return a reference to the file header, in unbyte-swapped form.
/// This method cannot fail.
const HMapHeader &HeaderMapImpl::getHeader() const { … }

/// getBucket - Return the specified hash table bucket from the header map,
/// bswap'ing its fields as appropriate.  If the bucket number is not valid,
/// this return a bucket with an empty key (0).
HMapBucket HeaderMapImpl::getBucket(unsigned BucketNo) const { … }

std::optional<StringRef> HeaderMapImpl::getString(unsigned StrTabIdx) const { … }

//===----------------------------------------------------------------------===//
// The Main Drivers
//===----------------------------------------------------------------------===//

/// dump - Print the contents of this headermap to stderr.
LLVM_DUMP_METHOD void HeaderMapImpl::dump() const { … }

StringRef HeaderMapImpl::lookupFilename(StringRef Filename,
                                        SmallVectorImpl<char> &DestPath) const { … }

StringRef HeaderMapImpl::reverseLookupFilename(StringRef DestPath) const { … }