common: Fix 'unchecked return code' warnings

Several tools are simply not checking return code of functions marked
with 'warn_unused_result'.

Provide wrappers for the read/write functions to avoid patching old
code and providing proper error handling.
Fix the remaining ones (calls to fgets() and system()).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/include/common.h b/include/common.h
index 93ef7f3..32b5d23 100644
--- a/include/common.h
+++ b/include/common.h
@@ -28,6 +28,7 @@
 #include <errno.h>
 #include <features.h>
 #include <inttypes.h>
+#include <unistd.h>
 #include <sys/sysmacros.h>
 
 #include "config.h"
@@ -226,6 +227,38 @@ long long util_get_bytes(const char *str);
 void util_print_bytes(long long bytes, int bracket);
 int util_srand(void);
 
+/*
+ * The following helpers are here to avoid compiler complaints about unchecked
+ * return code.
+ * FIXME: The proper fix would be to check the return code in all those places,
+ * but it's usually placed in old code which have no proper exit path and
+ * handling  errors requires rewriting a lot of code.
+ *
+ * WARNING: Please do not use these helpers in new code. Instead, make sure
+ * you check the function return code and provide coherent error handling in
+ * case of error.
+ */
+static inline ssize_t read_nocheck(int fd, void *buf, size_t count)
+{
+	return read(fd, buf, count);
+}
+
+static inline ssize_t write_nocheck(int fd, void *buf, size_t count)
+{
+	return write(fd, buf, count);
+}
+
+static inline ssize_t pread_nocheck(int fd, void *buf, size_t count,
+				    off_t offset)
+{
+	return pread(fd, buf, count, offset);
+}
+
+static inline ssize_t pwrite_nocheck(int fd, void *buf, size_t count,
+				     off_t offset)
+{
+	return pwrite(fd, buf, count, offset);
+}
 #ifdef __cplusplus
 }
 #endif