Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===--- TokenConcatenation.h - Token Concatenation Avoidance ---*- 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 TokenConcatenation class.

//

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

#ifndef LLVM_CLANG_LEX_TOKENCONCATENATION_H

#define LLVM_CLANG_LEX_TOKENCONCATENATION_H

#include "clang/Basic/TokenKinds.h"

namespace clang {

  class Preprocessor;

  class Token;

  /// TokenConcatenation class, which answers the question of

  ///   "Is it safe to emit two tokens without a whitespace between them, or

  ///    would that cause implicit concatenation of the tokens?"

  ///

  /// For example, it emitting two identifiers "foo" and "bar" next to each

  /// other would cause the lexer to produce one "foobar" token.  Emitting "1"

  /// and ")" next to each other is safe.

  ///

  class TokenConcatenation {

    const Preprocessor &PP;

    enum AvoidConcatInfo {

      /// By default, a token never needs to avoid concatenation.  Most tokens

      /// (e.g. ',', ')', etc) don't cause a problem when concatenated.

      aci_never_avoid_concat = 0,

      /// aci_custom_firstchar - AvoidConcat contains custom code to handle this

      /// token's requirements, and it needs to know the first character of the

      /// token.

      aci_custom_firstchar = 1,

      /// aci_custom - AvoidConcat contains custom code to handle this token's

      /// requirements, but it doesn't need to know the first character of the

      /// token.

      aci_custom = 2,

      /// aci_avoid_equal - Many tokens cannot be safely followed by an '='

      /// character.  For example, "<<" turns into "<<=" when followed by an =.

      aci_avoid_equal = 4

    };

    /// TokenInfo - This array contains information for each token on what

    /// action to take when avoiding concatenation of tokens in the AvoidConcat

    /// method.

    char TokenInfo[tok::NUM_TOKENS];

  public:

    TokenConcatenation(const Preprocessor &PP);

    bool AvoidConcat(const Token &PrevPrevTok,

                     const Token &PrevTok,

                     const Token &Tok) const;

  private:

    /// IsIdentifierStringPrefix - Return true if the spelling of the token

    /// is literally 'L', 'u', 'U', or 'u8'.

    bool IsIdentifierStringPrefix(const Token &Tok) const;

  };

  } // end clang namespace

#endif