build-sys: add --disable-tls

 * add AX_TLS autoconf macro

 * add --disabletls option

 * cleanup gen_uuid.c code to remove gcc warnings when compiled
   without TLS macro.

Signed-off-by: Karel Zak <kzak@redhat.com>

4 files changed, 81 insertions, 10 deletions

diff --git a/.gitignore b/.gitignore
index 5ab0d1d1e..9f6d8b85f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -43,3 +43,6 @@ libtool
 !m4/ltsugar.m4
 !m4/ltversion.m4
 !m4/lt~obsolete.m4
+
+# libuuid depends on AX_TLS macro
+!m4/tls.m4
diff --git a/configure.ac b/configure.ac
index 92f40d49c..0b3cf3590 100644
--- a/configure.ac
+++ b/configure.ac
@@ -128,6 +128,7 @@ AC_CHECK_FUNCS(
 	nanosleep \
 	personality \
 	updwtmp \
+	jrand48 \
 	lchown \
 	llseek \
 	lseek64 \
@@ -211,6 +212,15 @@ AC_DEFUN([UTIL_RESTORE_FLAGS], [
 ])
 
 
+AC_ARG_ENABLE([tls],
+  AS_HELP_STRING([--disable-tls], [disable use of thread local support]),
+  [], enable_tls=yes
+)
+if test "x$enable_tls" = xyes; then
+  AX_TLS
+fi
+
+
 AC_ARG_ENABLE([mount],
   AS_HELP_STRING([--disable-mount], [do not build mount utilities]),
   [], enable_mount=check
diff --git a/m4/tls.m4 b/m4/tls.m4
new file mode 100644
index 000000000..5644ba708
--- /dev/null
+++ b/m4/tls.m4
@@ -0,0 +1,48 @@
+# from http://autoconf-archive.cryp.to/ax_tls.html
+#
+# This was licensed under the GPL with the following exception:
+#
+# As a special exception, the respective Autoconf Macro's copyright
+# owner gives unlimited permission to copy, distribute and modify the
+# configure scripts that are the output of Autoconf when processing
+# the Macro. You need not follow the terms of the GNU General Public
+# License when using or distributing such scripts, even though
+# portions of the text of the Macro appear in them. The GNU General
+# Public License (GPL) does govern all other use of the material that
+# constitutes the Autoconf Macro.
+#
+# This special exception to the GPL applies to versions of the
+# Autoconf Macro released by the Autoconf Macro Archive. When you make
+# and distribute a modified version of the Autoconf Macro, you may
+# extend this special exception to the GPL to apply to your modified
+# version as well.
+#
+AC_DEFUN([AX_TLS], [
+  AC_MSG_CHECKING(for thread local storage (TLS) class)
+  AC_CACHE_VAL(ac_cv_tls, [
+    ax_tls_keywords="__thread __declspec(thread) none"
+    for ax_tls_keyword in $ax_tls_keywords; do
+       case $ax_tls_keyword in
+          none) ac_cv_tls=none ; break ;;
+          *)
+             AC_TRY_COMPILE(
+                [#include <stdlib.h>
+                 static void
+                 foo(void) {
+                 static ] $ax_tls_keyword [ int bar;
+                 exit(1);
+                 }],
+                 [],
+                 [ac_cv_tls=$ax_tls_keyword ; break],
+                 ac_cv_tls=none
+             )
+          esac
+    done
+])
+
+  if test "$ac_cv_tls" != "none"; then
+    dnl AC_DEFINE([TLS], [], [If the compiler supports a TLS storage class define it to that here])
+    AC_DEFINE_UNQUOTED([TLS], $ac_cv_tls, [If the compiler supports a TLS storage class define it to that here])
+  fi
+  AC_MSG_RESULT($ac_cv_tls)
+])
diff --git a/shlibs/uuid/src/gen_uuid.c b/shlibs/uuid/src/gen_uuid.c
index ab73c43ed..e0cb55742 100644
--- a/shlibs/uuid/src/gen_uuid.c
+++ b/shlibs/uuid/src/gen_uuid.c
@@ -175,7 +175,6 @@ static void get_random_bytes(void *buf, int nbytes)
 	int i, n = nbytes, fd = get_random_fd();
 	int lose_counter = 0;
 	unsigned char *cp = (unsigned char *) buf;
-	unsigned short tmp_seed[3];
 
 	if (fd >= 0) {
 		while (n > 0) {
@@ -197,13 +196,18 @@ static void get_random_bytes(void *buf, int nbytes)
 	 */
 	for (cp = buf, i = 0; i < nbytes; i++)
 		*cp++ ^= (rand() >> 7) & 0xFF;
+
 #ifdef DO_JRAND_MIX
-	memcpy(tmp_seed, jrand_seed, sizeof(tmp_seed));
-	jrand_seed[2] = jrand_seed[2] ^ syscall(__NR_gettid);
-	for (cp = buf, i = 0; i < nbytes; i++)
-		*cp++ ^= (jrand48(tmp_seed) >> 7) & 0xFF;
-	memcpy(jrand_seed, tmp_seed,
-	       sizeof(jrand_seed)-sizeof(unsigned short));
+	{
+		unsigned short tmp_seed[3];
+
+		memcpy(tmp_seed, jrand_seed, sizeof(tmp_seed));
+		jrand_seed[2] = jrand_seed[2] ^ syscall(__NR_gettid);
+		for (cp = buf, i = 0; i < nbytes; i++)
+			*cp++ ^= (jrand48(tmp_seed) >> 7) & 0xFF;
+		memcpy(jrand_seed, tmp_seed,
+		       sizeof(jrand_seed)-sizeof(unsigned short));
+	}
 #endif
 
 	return;
@@ -415,6 +419,8 @@ try_again:
 	return 0;
 }
 
+#if defined(USE_UUIDD) && defined(HAVE_SYS_UN_H)
+/* used in get_uuid_via_daemon() only */
 static ssize_t read_all(int fd, char *buf, size_t count)
 {
 	ssize_t ret;
@@ -459,7 +465,6 @@ static void close_all_fds(void)
 		close(i);
 }
 
-
 /*
  * Try using the uuidd daemon to generate the UUID
  *
@@ -467,7 +472,6 @@ static void close_all_fds(void)
  */
 static int get_uuid_via_daemon(int op, uuid_t out, int *num)
 {
-#if defined(USE_UUIDD) && defined(HAVE_SYS_UN_H)
 	char op_buf[64];
 	int op_len;
 	int s;
@@ -534,10 +538,16 @@ static int get_uuid_via_daemon(int op, uuid_t out, int *num)
 
 fail:
 	close(s);
-#endif
 	return -1;
 }
 
+#else /* !defined(USE_UUIDD) && defined(HAVE_SYS_UN_H) */
+static int get_uuid_via_daemon(int op, uuid_t out, int *num)
+{
+	return -1;
+}
+#endif
+
 void uuid__generate_time(uuid_t out, int *num)
 {
 	static unsigned char node_id[6];