package/mpd/0001-configure.ac-check-if-libatomic-is-needed.patch

   1 From 8eaf14a17244aaf000b4d19e4fde4a637576939f Mon Sep 17 00:00:00 2001
   2 From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
   3 Date: Sun, 7 Feb 2016 21:40:47 +0100
   4 Subject: [PATCH] configure.ac: check if libatomic is needed
   5
   6 The mpd source code uses the C++11 <atomic> functionality, which
   7 internally is implemented using the __atomic_*() gcc built-ins. On
   8 certain architectures, the __atomic_*() built-ins are implemented in
   9 the libatomic library that comes with the rest of the gcc runtime. Due
  10 to this, code using <atomic> might need to link against libatomic,
  11 otherwise one hits build issues such as:
  12
  13 GlobalEvents.cxx:(.text._ZN12GlobalEvents4EmitENS_5EventE+0x14): undefined reference to `__atomic_fetch_or_4'
  14
  15 on an architecture like SPARC.
  16
  17 To solve this, a configure.ac check is added to know if we need to
  18 link against libatomic or not.
  19
  20 Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  21 ---
  22  configure.ac | 2 ++
  23  1 file changed, 2 insertions(+)
  24
  25 diff --git a/configure.ac b/configure.ac
  26 index 107b45a..8e6fab7 100644
  27 --- a/configure.ac
  28 +++ b/configure.ac
  29 @@ -233,6 +233,8 @@ if test x$have_pthread_setname_np = xyes; then
  30         AC_DEFINE(HAVE_PTHREAD_SETNAME_NP, 1, [Is pthread_setname_np() available?])
  31  fi
  32
  33 +AC_SEARCH_LIBS([__atomic_load_4], [atomic])
  34 +
  35  dnl ---------------------------------------------------------------------------
  36  dnl Event loop selection
  37  dnl ---------------------------------------------------------------------------
  38 --
  39 2.6.4
  40