X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Freadahead%2Fsd-readahead.c;h=4a096eed427779c3b326c3bef08daa903d5dc419;hb=29f6aadd5302320d5a7a3868b607eb83687bdfd0;hp=c5cfe6710732c900a459510fd937aefca26ec44e;hpb=e5e83e8362e946890ac991fc86a2c5869f9befdf;p=elogind.git

diff --git a/src/readahead/sd-readahead.c b/src/readahead/sd-readahead.c
index c5cfe6710..4a096eed4 100644
--- a/src/readahead/sd-readahead.c
+++ b/src/readahead/sd-readahead.c
@@ -25,7 +25,7 @@
 ***/
 
 #ifndef _GNU_SOURCE
-#define _GNU_SOURCE
+#  define _GNU_SOURCE
 #endif
 
 #include <unistd.h>
@@ -37,6 +37,18 @@
 
 #include "sd-readahead.h"
 
+#if (__GNUC__ >= 4)
+#  ifdef SD_EXPORT_SYMBOLS
+/* Export symbols */
+#    define _sd_export_ __attribute__ ((visibility("default")))
+#  else
+/* Don't export the symbols */
+#    define _sd_export_ __attribute__ ((visibility("hidden")))
+#  endif
+#else
+#  define _sd_export_
+#endif
+
 static int touch(const char *path) {
 
 #if !defined(DISABLE_SYSTEMD) && defined(__linux__)
@@ -45,7 +57,8 @@ static int touch(const char *path) {
         mkdir("/run/systemd", 0755);
         mkdir("/run/systemd/readahead", 0755);
 
-        if ((fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0666)) < 0)
+        fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0666);
+        if (fd < 0)
                 return -errno;
 
         for (;;) {
@@ -60,7 +73,7 @@ static int touch(const char *path) {
         return 0;
 }
 
-int sd_readahead(const char *action) {
+_sd_export_ int sd_readahead(const char *action) {
 
         if (!action)
                 return -EINVAL;