I'm trying to compile a pre-existing c++ package on my mac osx leopard machine, and get the following error:
error: no matching function for call to 'getline(char**, size_t*, FILE*&)'
This is probably because getline() is a GNU specific extension.
Can I somehow make the osx default g++ compiler recognize such GNU specific extensions?
(if not, I could always supply my own implementation or GNUs original one, but I prefer to have a "cleaner" solution if possible)
getline is defined in stdio.h in glibc version 2.10 and later, but not in earlier versions, nor (so far; added 10.5 definitely didn't have getline, and 10.7 definitely does) in the BSD derived libc.
The change in the GNU libraries came about because of a change in the POSIX 2008 standard, which now includes getline.
Presumably, this will propogate to other libc over time. In the mean time, I understand that it is causing trouble for a lot of projects.
Generally, the solution is to use autoconf or some similar tool to determine whether the current platform already has getline or not, and supply your own definition only when needed.
Example:
# configure.ac
AC_CHECK_FUNCS([getline])
// compat.h
#include "config.h"
#ifndef HAVE_GETLINE
ssize_t getline(char **lineptr, size_t *n, FILE *stream);
#endif
// getline.c
ssize_t getline(char **lineptr, size_t *n, FILE *stream) {
/* definition */
}
# Makefile.am
program_LDADD = $(if $(HAVE_GETLINE),,getline.o)
or something along those lines, you'll have to adjust it to match your own program.
I'm not sure I've ever seen that specific definition of 'getline' here is the one I know of which uses c++ streams+strings.
