Re: C++ variants in reentrant bison/flex combination

[Hans Åberg]

> On 22 Aug 2016, at 11:48, PICHLMEIER Florian <address@hidden> wrote:

> I am trying to modify an existing nonreentrant bison/flex combination to be 
> reentrant.
> The parser is built from the C++ skeleton lalr1.cc and the scanner with the 
> plain C version of flex.

> The problem I encounter during compilation is the error "YYSTYPE does not 
> name type” 

There is a C++ calculator example in the Bison distribution that you might 
check out. Otherwise, I have the code below, which I think originally comes 
from that example:

There, YYSTYPE is defined in a '%code requires’ clause. It also shows how to 
use %locations for error messages. And yyrestart() is used in the error 
recovery grammar rule.


%skeleton "lalr1.cc"                          /*  -*- C++ -*- */
%require "3.0.4"
%defines

%define api.namespace {my}
%define parser_class_name {my_parser}

%code requires {
#include <string>
...

#define YYSTYPE my::object
class parser;
}

// The parsing context.
%parse-param { parser& driver }
%lex-param   { parser& driver }

%locations
%initial-action
{
  // Initialize the initial location.
  @$.begin.filename = @$.end.filename = &driver.file;
};

%debug
%error-verbose

%code {
  #include "driver.hh"

  void yyrestart(FILE *input_file);

  ...
}

%token END      0 "end of file”
...

%%
...

%%

%%

void
my::my_parser::error(const my::my_parser::location_type& l,
                          const std::string& m)
{
  driver.error(l, m);
}