llvm/clang/lib/Lex/PPLexerChange.cpp

//===--- PPLexerChange.cpp - Handle changing lexers in the preprocessor ---===//
//
// 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 pieces of the Preprocessor interface that manage the
// current lexer stack.
//
//===----------------------------------------------------------------------===//

#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/PreprocessorOptions.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBufferRef.h"
#include "llvm/Support/Path.h"
#include <optional>

usingnamespaceclang;

//===----------------------------------------------------------------------===//
// Miscellaneous Methods.
//===----------------------------------------------------------------------===//

/// isInPrimaryFile - Return true if we're in the top-level file, not in a
/// \#include.  This looks through macro expansions and active _Pragma lexers.
bool Preprocessor::isInPrimaryFile() const { … }

/// getCurrentLexer - Return the current file lexer being lexed from.  Note
/// that this ignores any potentially active macro expansions and _Pragma
/// expansions going on at the time.
PreprocessorLexer *Preprocessor::getCurrentFileLexer() const { … }


//===----------------------------------------------------------------------===//
// Methods for Entering and Callbacks for leaving various contexts
//===----------------------------------------------------------------------===//

/// EnterSourceFile - Add a source file to the top of the include stack and
/// start lexing tokens from it instead of the current buffer.
bool Preprocessor::EnterSourceFile(FileID FID, ConstSearchDirIterator CurDir,
                                   SourceLocation Loc,
                                   bool IsFirstIncludeOfFile) { … }

/// EnterSourceFileWithLexer - Add a source file to the top of the include stack
///  and start lexing tokens from it instead of the current buffer.
void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer,
                                            ConstSearchDirIterator CurDir) { … }

/// EnterMacro - Add a Macro to the top of the include stack and start lexing
/// tokens from it instead of the current buffer.
void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd,
                              MacroInfo *Macro, MacroArgs *Args) { … }

/// EnterTokenStream - Add a "macro" context to the top of the include stack,
/// which will cause the lexer to start returning the specified tokens.
///
/// If DisableMacroExpansion is true, tokens lexed from the token stream will
/// not be subject to further macro expansion.  Otherwise, these tokens will
/// be re-macro-expanded when/if expansion is enabled.
///
/// If OwnsTokens is false, this method assumes that the specified stream of
/// tokens has a permanent owner somewhere, so they do not need to be copied.
/// If it is true, it assumes the array of tokens is allocated with new[] and
/// must be freed.
///
void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
                                    bool DisableMacroExpansion, bool OwnsTokens,
                                    bool IsReinject) { … }

/// Compute the relative path that names the given file relative to
/// the given directory.
static void computeRelativePath(FileManager &FM, const DirectoryEntry *Dir,
                                FileEntryRef File, SmallString<128> &Result) { … }

void Preprocessor::PropagateLineStartLeadingSpaceInfo(Token &Result) { … }

/// Determine the location to use as the end of the buffer for a lexer.
///
/// If the file ends with a newline, form the EOF token on the newline itself,
/// rather than "on the line following it", which doesn't exist.  This makes
/// diagnostics relating to the end of file include the last file that the user
/// actually typed, which is goodness.
const char *Preprocessor::getCurLexerEndPos() { … }

static void collectAllSubModulesWithUmbrellaHeader(
    const Module &Mod, SmallVectorImpl<const Module *> &SubMods) { … }

void Preprocessor::diagnoseMissingHeaderInUmbrellaDir(const Module &Mod) { … }

/// HandleEndOfFile - This callback is invoked when the lexer hits the end of
/// the current file.  This either returns the EOF token or pops a level off
/// the include stack and keeps going.
bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) { … }

/// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer
/// hits the end of its token stream.
bool Preprocessor::HandleEndOfTokenLexer(Token &Result) { … }

/// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the
/// lexer stack.  This should only be used in situations where the current
/// state of the top-of-stack lexer is unknown.
void Preprocessor::RemoveTopOfLexerStack() { … }

/// HandleMicrosoftCommentPaste - When the macro expander pastes together a
/// comment (/##/) in microsoft mode, this method handles updating the current
/// state, returning the token on the next source line.
void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) { … }

void Preprocessor::EnterSubmodule(Module *M, SourceLocation ImportLoc,
                                  bool ForPragma) { … }

bool Preprocessor::needModuleMacros() const { … }

Module *Preprocessor::LeaveSubmodule(bool ForPragma) { … }