Fix: tls-compat.h exposes compiler-dependent public configuration
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Mon, 20 Apr 2020 15:30:49 +0000 (11:30 -0400)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Mon, 20 Apr 2020 16:47:29 +0000 (12:47 -0400)
commit109267f653502cf5ef5ada5d098167b9726daa2d
tree9d5409b4653f114b4071d37a903a04b97c960f83
parente2b8e1f623338afb1760a8033785f4904c645c86
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>
configure.ac
include/urcu/tls-compat.h
m4/ax_tls.m4 [deleted file]
This page took 0.033564 seconds and 4 git commands to generate.