[Flex-help] yyget_lineno missing in lex.yy.c

[John G. <joh...@gm...>]

Hi,

The project I work with (https://github.com/rtcmix/rtcmix) embeds a lexer built with flex. This builds correctly using flex 2.5.35 (macOS) and all previous versions. We use the lex compatibility mode flag (-l).

Recently, we received a report from a user on Ubuntu 16.04, which includes flex 2.5.4, about not being able to build our software. The problem is that the yyget_lineno, yyset_lineno, and yylex_destroy functions are not included in the lex.yy.c file generated by flex 2.5.4. Adding "%option yylineno" at the top of our .l file did not help -- not surprisingly, since the docs say that lex compat. mode already implies %option yylineno. We use no other options.

Is there something simple that I'm missing here? Has something changed that requires us to compile differently than we've had to before? Or is there something missing in this user's installation?

Thanks much,
John