1.5.5 Considerations when Compiling GLR Parsers

The GLR parsers require a compiler for ISO C89 or later. In addition, they use the inline keyword, which is not C89, but is C99 and is a common extension in pre-C99 compilers. It is up to the user of these parsers to handle portability issues. For instance, if using Autoconf and the Autoconf macro AC_C_INLINE, a mere

%{
  #include <config.h>
%}

will suffice. Otherwise, we suggest

%{
  #if (__STDC_VERSION__ < 199901 && ! defined __GNUC__ \
       && ! defined inline)
  # define inline
  #endif
%}