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Date: Mon, 11 Feb 2013 15:39:44 +0100
From: Szabolcs Nagy <>
Subject: Re: [PATCH 2/3] Have different definitions of
 __pthread_tsd_main agree in size

* Jens Gustedt <> [2013-02-11 15:07:28 +0100]:
> the current model there is even the danger that environ and __environ
> split into two different objects.
> char **environ;
> int main(void) {
>   return (long)&environ;
> }
> When compile-linking this with musl I get both symbols environ and
> __environ linked in.

and that is precisely what posix requires

> So it would at least be good that the internal use of it in musl would
> be consistent and the C library would not see two distinct objects.


"The ISO C standard and this volume of POSIX.1-2008 do not conflict
on the use of environ, but some historical implementations of environ
may cause a conflict. As long as environ is treated in the same way
as an entry point (for example, fork()), it conforms to both standards.
A library can contain fork(), but if there is a user-provided fork(),
that fork() is given precedence and no problem ensues.
The situation is similar for environ: the definition in this volume of
POSIX.1-2008 is to be used if there is no user-provided environ to take
precedence. At least three implementations are known to exist that
solve this problem."

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