Re: Bug with '#line' directive in bison 3.0.2

[Stephen Cameron]

Additional data point.  Manually editing y.tab.c and y.tab.h to change the
'#line...' directives to all begin on a new line makes it work.

-- steve


On Sun, Sep 28, 2014 at 8:43 PM, Stephen Cameron <address@hidden>
wrote:

> Hi,
>
> I think I have found a bug in bison v. 3.0.2.
>
> address@hidden ~/github/simple-expression-parser $ yacc --version
> bison (GNU Bison) 3.0.2
> Written by Robert Corbett and Richard Stallman.
>
> Copyright (C) 2013 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> address@hidden ~/github/simple-expression-parser $
>
> Note that is the version of bison shipped with e.g. Linux Mint 17.
>
> Below is some output (y.tab.h) of yacc (bison) v 3.0.2
>
> Notice the '#line' directive which does not start at the beginning of a
> line:
>
> "union #line 49 "expression-parser.y" /* yacc.c:1909  */"
>
> gcc will not compile this.  I think that means it's a bug in bison.
> Earlier versions of bison produce correct output (e.g. v. 2.5 works
> correctly, and the '#line' directive begins on a new line.)
>
>
> -------8<--------8<-------8<-------8<--------8<-------8<-------8<--------8<-------8<
> [...]
> /* Value type.  */
> #if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
> typedef union #line 49 "expression-parser.y" /* yacc.c:1909  */
> valtype
>  YYSTYPE;
> union #line 49 "expression-parser.y" /* yacc.c:1909  */
> valtype
>
> {
> #line 49 "expression-parser.y" /* yacc.c:1909  */
>
>         struct parser_value_type {
>                 double dval;
>                 long long ival;
>                 int has_dval;
>                 int has_error;
>         } v;
>
> #line 77 "y.tab.h" /* yacc.c:1909  */
> };
> # define YYSTYPE_IS_TRIVIAL 1
> [...]
>
> -------8<--------8<-------8<-------8<--------8<-------8<-------8<--------8<-------8<
>
> The program which caused this is a simple arithmetic expression parser
> (basic yacc 101 stuff).  It is here:
> https://github.com/smcameron/simple-expression-parser
>
> Thank you.
>
> -- steve
>
>
>