parse_location.h

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   it under the terms of the GNU General Public License, version 2.0,
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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   You should have received a copy of the GNU General Public License
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   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#ifndef PARSE_LOCATION_INCLUDED
#define PARSE_LOCATION_INCLUDED

#include <cstdlib>  // size_t

/**
  Helper class for the MY_SQL_PARSER_LTYPE
*/
struct Symbol_location {
  const char *start = nullptr;  // token start
  const char *end = nullptr;    // the 1st byte after the token

  bool is_empty() const { return length() == 0; }
  size_t length() const { return static_cast<size_t>(end - start); }
};

/**
  Bison "location" class
*/
struct MY_SQL_PARSER_LTYPE {
  Symbol_location cpp;  // token location in the preprocessed buffer
  Symbol_location raw;  // token location in the raw buffer

  bool is_empty() const { return cpp.is_empty(); }
};

/*
  Note: MY_SQL_PARSER_LTYPE doesn't overload a default constructor (as
  well an underlying Symbol_location).  OTOH if we need a
  zero-initialized POS, MY_SQL_PARSER_LTYPE or Symbol_location object,
  we can simply call POS(), MY_SQL_PARSER_LTYPE() or
  Symbol_location(): C++ does value-initialization in that case.
*/
using POS = MY_SQL_PARSER_LTYPE;

// signal Bison that we have our own MY_SQL_PARSER_LTYPE
#define MY_SQL_PARSER_LTYPE_IS_DECLARED 1

/**
  Bison calls this macro:
  1. each time a rule is matched and
  2. to compute a syntax error location.

  @param [out] Current location of the whole matched rule
  @param Rhs           locations of all right hand side elements in the rule
  @param N             number of right hand side elements in the rule
*/
#define YYLLOC_DEFAULT(Current, Rhs, N)                                   \
  do                                                                      \
    if (N) {                                                              \
      (Current).cpp.start = YYRHSLOC(Rhs, 1).cpp.start;                   \
      (Current).cpp.end = YYRHSLOC(Rhs, N).cpp.end;                       \
      (Current).raw.start = YYRHSLOC(Rhs, 1).raw.start;                   \
      (Current).raw.end = YYRHSLOC(Rhs, N).raw.end;                       \
    } else {                                                              \
      (Current).cpp.start = (Current).cpp.end = YYRHSLOC(Rhs, 0).cpp.end; \
      (Current).raw.start = (Current).raw.end = YYRHSLOC(Rhs, 0).raw.end; \
    }                                                                     \
  while (0)

#endif /* PARSE_LOCATION_INCLUDED */