compiler: add compiler.h header

src/lxc/Makefile.am

@@ -6,6 +6,7 @@ noinst_HEADERS = attach.h \
 		 caps.h \
 		 cgroups/cgroup.h \
 		 cgroups/cgroup_utils.h \
+		 compiler.h \
 		 conf.h \
 		 confile.h \
 		 confile_utils.h \
@@ -86,6 +87,7 @@ liblxc_la_SOURCES = af_unix.c af_unix.h \
 		    cgroups/cgfsng.c \
 		    cgroups/cgroup.c cgroups/cgroup.h \
 		    cgroups/cgroup_utils.c cgroups/cgroup_utils.h \
+		    compiler.h \
 		    commands.c commands.h \
 		    commands_utils.c commands_utils.h \
 		    conf.c conf.h \

src/lxc/compiler.h

+/* liblxcapi
+ *
+ * Copyright © 2018 Christian Brauner <christian.brauner@ubuntu.com>.
+ * Copyright © 2018 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __LXC_COMPILER_H
+#define __LXC_COMPILER_H
+
+#include "config.h"
+
+#ifndef thread_local
+#if __STDC_VERSION__ >= 201112L &&    \
+    !(defined(__STDC_NO_THREADS__) || \
+      (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
+#define thread_local _Thread_local
+#else
+#define thread_local __thread
+#endif
+#endif
+
+#endif /* __LXC_COMPILER_H */

src/lxc/conf.c

@@ -124,7 +124,7 @@ lxc_log_define(conf, lxc);
  * This is used in the error calls.
  */
 #ifdef HAVE_TLS
-__thread struct lxc_conf *current_config;
+thread_local struct lxc_conf *current_config;
 #else
 struct lxc_conf *current_config;
 #endif

src/lxc/conf.h

@@ -38,6 +38,7 @@
 #include <sys/resource.h>
 #endif
 
+#include "compiler.h"
 #include "list.h"
 #include "ringbuf.h"
 #include "start.h" /* for lxc_handler */
@@ -379,7 +380,7 @@ extern int write_id_mapping(enum idtype idtype, pid_t pid, const char *buf,
 			    size_t buf_size);
 
 #ifdef HAVE_TLS
-extern __thread struct lxc_conf *current_config;
+extern thread_local struct lxc_conf *current_config;
 #else
 extern struct lxc_conf *current_config;
 #endif

src/lxc/initutils.c

@@ -28,6 +28,7 @@
 #include "initutils.h"
 #include "log.h"
 #include "macro.h"
+#include "compiler.h"
 
 #ifndef HAVE_STRLCPY
 #include "include/strlcpy.h"
@@ -72,9 +73,9 @@ const char *lxc_global_config_value(const char *option_name)
 
 	/* placed in the thread local storage pool for non-bionic targets */
 #ifdef HAVE_TLS
-	static __thread const char *values[sizeof(options) / sizeof(options[0])] = { 0 };
+	static thread_local const char *values[sizeof(options) / sizeof(options[0])] = {0};
 #else
-	static const char *values[sizeof(options) / sizeof(options[0])] = { 0 };
+	static const char *values[sizeof(options) / sizeof(options[0])] = {0};
 #endif
 
 	/* user_config_path is freed as soon as it is used */