Re: multithread CPPFLAGS

[Bruno Haible]

Yoann Vandoorselaere wrote:
> - Isolate thread specific CPP flags into THREADCPPFLAGS (this is useful
> for a library to propagate threads specific CPPFLAGS).

What do you mean by that? Do you mean that the users of a library need to
use the same CPPFLAGS as those with which library was compiled? This would
not be right in the majority of cases, IMO.

Let's look at the two cases:

  - OSF/1: need to modify CPPFLAGS so that cc groks <pthread.h>.
    If your library's header files make use of <pthread.h> then the user
    of your library will require the same CPPFLAGS, otherwise not.
    In the first case the program that uses the library should use
    threadlib.m4 too.

  - AIX, FreeBSD, Solaris: need to modify CPPFLAGS in order to disable
    the single-thread-optimized 'errno'. If the program that uses your library
    uses multiple threads, it needs to modify CPPFLAGS. If it is a single-
    threaded program, it does not need it.

What's the case you have in mind?

Bruno