common/safe_io.h: warn about unchecked returns

Signed-off-by: Colin McCabe <colin.mccabe@dreamhost.com>

diff --git a/src/common/safe_io.h b/src/common/safe_io.h
index 8f89b0881088b08594acc04f16fc692441f81234..3a975d72b9093d960ad8bb3d5fd3e1545f50fe8c 100644 (file)
--- a/src/common/safe_io.h
+++ b/src/common/safe_io.h
@@ -25,17 +25,23 @@ extern "C" {
    * These retry on EINTR, and on error return -errno instead of returning
    * 1 and setting errno).
    */
-  ssize_t safe_read(int fd, void *buf, size_t count);
-  ssize_t safe_write(int fd, const void *buf, size_t count);
-  ssize_t safe_pread(int fd, void *buf, size_t count, off_t offset);
-  ssize_t safe_pwrite(int fd, const void *buf, size_t count, off_t offset);
+  ssize_t safe_read(int fd, void *buf, size_t count)
+    __attribute__ ((warn_unused_result));
+  ssize_t safe_write(int fd, const void *buf, size_t count)
+    __attribute__ ((warn_unused_result));
+  ssize_t safe_pread(int fd, void *buf, size_t count, off_t offset)
+    __attribute__ ((warn_unused_result));
+  ssize_t safe_pwrite(int fd, const void *buf, size_t count, off_t offset)
+    __attribute__ ((warn_unused_result));
 
   /*
    * Same as the above functions, but return -EDOM unless exactly the requested
    * number of bytes can be read.
    */
-  ssize_t safe_read_exact(int fd, void *buf, size_t count);
-  ssize_t safe_pread_exact(int fd, void *buf, size_t count, off_t offset);
+  ssize_t safe_read_exact(int fd, void *buf, size_t count)
+    __attribute__ ((warn_unused_result));
+  ssize_t safe_pread_exact(int fd, void *buf, size_t count, off_t offset)
+    __attribute__ ((warn_unused_result));
 
 #ifdef __cplusplus
 }