From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 20 Apr 2020 15:30:49 +0000 (-0400)
Subject: Fix: tls-compat.h exposes compiler-dependent public configuration
X-Git-Tag: v0.13.0~59
X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=commitdiff_plain;h=109267f653502cf5ef5ada5d098167b9726daa2d;hp=109267f653502cf5ef5ada5d098167b9726daa2d

Fix: tls-compat.h exposes compiler-dependent public configuration

Exposing the storage class chosen by ax_tls.m4 in a public header is
a bad idea, because if a recent gcc is used when configuring
liburcu, thus detecting C11, it will choose _Thread_local. Then, if an
external project uses urcu/tls-compat.h with an older gcc (e.g. 4.8),
it will fail to build, because that storage class is unknown, and
__thread should be used instead.

Therefore, use a preprocessor conditional on __cplusplus to detect C++11
(and use thread_local). Else, the STDC version is used to select
_Thread_local. Else check if _MSC_VER is defined to select
__declspec(thread), or else rely on __thread as fallback.

Remove ax_tls.m4 because it is now unused.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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