//===--- FormatTokenLexer.h - Format C++ code ----------------*- 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

//

//===----------------------------------------------------------------------===//

///

/// \file

/// This file contains FormatTokenLexer, which tokenizes a source file

/// into a token stream suitable for ClangFormat.

///

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_LIB_FORMAT_FORMATTOKENLEXER_H

#define LLVM_CLANG_LIB_FORMAT_FORMATTOKENLEXER_H

#include "Encoding.h"

#include "FormatToken.h"

#include "clang/Basic/SourceLocation.h"

#include "clang/Basic/SourceManager.h"

#include "clang/Format/Format.h"

#include "llvm/ADT/MapVector.h"

#include "llvm/ADT/StringSet.h"

#include "llvm/Support/Regex.h"

#include <stack>

namespace clang {

namespace format {

enum LexerState {

  NORMAL,

  TEMPLATE_STRING,

  TOKEN_STASHED,

};

class FormatTokenLexer {

public:

  FormatTokenLexer(const SourceManager &SourceMgr, FileID ID, unsigned Column,

                   const FormatStyle &Style, encoding::Encoding Encoding,

                   llvm::SpecificBumpPtrAllocator<FormatToken> &Allocator,

                   IdentifierTable &IdentTable);

  ArrayRef<FormatToken *> lex();

  const AdditionalKeywords &getKeywords() { return Keywords; }

private:

  void tryMergePreviousTokens();

  bool tryMergeLessLess();

  bool tryMergeNSStringLiteral();

  bool tryMergeJSPrivateIdentifier();

  bool tryMergeCSharpStringLiteral();

  bool tryMergeCSharpKeywordVariables();

  bool tryMergeNullishCoalescingEqual();

  bool tryTransformCSharpForEach();

  bool tryMergeForEach();

  bool tryTransformTryUsageForC();

  bool tryMergeTokens(ArrayRef<tok::TokenKind> Kinds, TokenType NewType);

  // Returns \c true if \p Tok can only be followed by an operand in JavaScript.

  bool precedesOperand(FormatToken *Tok);

  bool canPrecedeRegexLiteral(FormatToken *Prev);

  // Tries to parse a JavaScript Regex literal starting at the current token,

  // if that begins with a slash and is in a location where JavaScript allows

  // regex literals. Changes the current token to a regex literal and updates

  // its text if successful.

  void tryParseJSRegexLiteral();

  // Handles JavaScript template strings.

  //

  // JavaScript template strings use backticks ('`') as delimiters, and allow

  // embedding expressions nested in ${expr-here}. Template strings can be

  // nested recursively, i.e. expressions can contain template strings in turn.

  //

  // The code below parses starting from a backtick, up to a closing backtick or

  // an opening ${. It also maintains a stack of lexing contexts to handle

  // nested template parts by balancing curly braces.

  void handleTemplateStrings();

  void handleCSharpVerbatimAndInterpolatedStrings();

  void tryParsePythonComment();

  bool tryMerge_TMacro();

  bool tryMergeConflictMarkers();

  FormatToken *getStashedToken();

  FormatToken *getNextToken();

  FormatToken *FormatTok;

  bool IsFirstToken;

  std::stack<LexerState> StateStack;

  unsigned Column;

  unsigned TrailingWhitespace;

  std::unique_ptr<Lexer> Lex;

  const SourceManager &SourceMgr;

  FileID ID;

  const FormatStyle &Style;

  IdentifierTable &IdentTable;

  AdditionalKeywords Keywords;

  encoding::Encoding Encoding;

  llvm::SpecificBumpPtrAllocator<FormatToken> &Allocator;

  // Index (in 'Tokens') of the last token that starts a new line.

  unsigned FirstInLineIndex;

  SmallVector<FormatToken *, 16> Tokens;

  llvm::SmallMapVector<IdentifierInfo *, TokenType, 8> Macros;

  bool FormattingDisabled;

  llvm::Regex MacroBlockBeginRegex;

  llvm::Regex MacroBlockEndRegex;

  // Targets that may appear inside a C# attribute.

  static const llvm::StringSet<> CSharpAttributeTargets;

  void readRawToken(FormatToken &Tok);

  void resetLexer(unsigned Offset);

};

} // namespace format

} // namespace clang

#endif