On 12/13/19 2:58 PM, Adrian Bunk wrote:
On Fri, Dec 13, 2019 at 01:55:33PM -0800, Khem Raj wrote:
On Thu, Dec 12, 2019 at 8:37 PM Adrian Bunk <[email protected]> wrote:
On Thu, Dec 12, 2019 at 12:22:52PM -0800, Khem Raj wrote:
...
+_POSIX_SOURCE is app-defined not system
This is true for musl, not for glibc.
The handling of _POSIX_SOURCE and _POSIX_VERSION differs between musl
and glibc due to glibc supporting older POSIX versions, and glibc also
supporting developers of portable code to select some specific older
POSIX version.
No thats not right.
_POSIX_SOURCE (like all FTMs) is
defined by the application to request a feature/standards profile
it's not libc telling you "this is posix" or anything like that.
It is also defined when _POSIX_C_SOURCE is defined, or _GNU_SOURCE,
or when the default non-strict gcc mode is used.
The latter means that it is in practice nearly always defined when the
libc supports applications written against older versions of POSIX.
but these macros are not used in this case so its irrelevant here.
_POSIX_VERSION tells you that
...
_POSIX_VERSION being defined tells you that you have unistd.h included.
With glibc the value of _POSIX_VERSION depends on what feature/standards
profile the application has requested.
I would not look into how glibc does something and call it standard. It
guards these definitions by its internal defines ( prefixed with __)
which is internal to a libc implementation, applications are not exposed
to private namespace.
cu
Adrian
--
_______________________________________________
Openembedded-devel mailing list
[email protected]
http://lists.openembedded.org/mailman/listinfo/openembedded-devel
