libbb: introduce kernel-style BUILD_BUG_ON()

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

5 files changed, 12 insertions, 21 deletions

diff --git a/networking/ftpgetput.c b/networking/ftpgetput.c
index 8283366cc..b398bc874 100644
--- a/networking/ftpgetput.c
+++ b/networking/ftpgetput.c
@@ -62,9 +62,6 @@ struct globals {
 } FIX_ALIASING;
 #define G (*(struct globals*)&bb_common_bufsiz1)
 enum { BUFSZ = COMMON_BUFSIZE - offsetof(struct globals, buf) };
-struct BUG_G_too_big {
-	char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
-};
 #define user           (G.user          )
 #define password       (G.password      )
 #define lsa            (G.lsa           )
@@ -72,7 +69,9 @@ struct BUG_G_too_big {
 #define verbose_flag   (G.verbose_flag  )
 #define do_continue    (G.do_continue   )
 #define buf            (G.buf           )
-#define INIT_G() do { } while (0)
+#define INIT_G() do { \
+	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
+} while (0)
 
 
 static void ftp_die(const char *msg) NORETURN;
diff --git a/networking/isrv.c b/networking/isrv.c
index 1c6491edd..3673db715 100644
--- a/networking/isrv.c
+++ b/networking/isrv.c
@@ -194,7 +194,6 @@ static void handle_accept(isrv_state_t *state, int fd)
 		remove_peer(state, n); /* unsuccesful peer start */
 }
 
-void BUG_sizeof_fd_set_is_strange(void);
 static void handle_fd_set(isrv_state_t *state, fd_set *fds, int (*h)(int, void **))
 {
 	enum { LONG_CNT = sizeof(fd_set) / sizeof(long) };
@@ -203,8 +202,7 @@ static void handle_fd_set(isrv_state_t *state, fd_set *fds, int (*h)(int, void *
 	/* need to know value at _the beginning_ of this routine */
 	int fd_cnt = FD_COUNT;
 
-	if (LONG_CNT * sizeof(long) != sizeof(fd_set))
-		BUG_sizeof_fd_set_is_strange();
+	BUILD_BUG_ON(LONG_CNT * sizeof(long) != sizeof(fd_set));
 
 	fds_pos = 0;
 	while (1) {
diff --git a/networking/ping.c b/networking/ping.c
index dcbf19682..0eb1ae799 100644
--- a/networking/ping.c
+++ b/networking/ping.c
@@ -396,10 +396,8 @@ struct globals {
 #define dotted       (G.dotted      )
 #define pingaddr     (G.pingaddr    )
 #define rcvd_tbl     (G.rcvd_tbl    )
-void BUG_ping_globals_too_big(void);
 #define INIT_G() do { \
-	if (sizeof(G) > COMMON_BUFSIZE) \
-		BUG_ping_globals_too_big(); \
+	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 	datalen = DEFDATALEN; \
 	timeout = MAXWAIT; \
 	tmin = UINT_MAX; \
@@ -732,7 +730,6 @@ static void ping4(len_and_sockaddr *lsa)
 	}
 }
 #if ENABLE_PING6
-extern int BUG_bad_offsetof_icmp6_cksum(void);
 static void ping6(len_and_sockaddr *lsa)
 {
 	int sockopt;
@@ -769,8 +766,7 @@ static void ping6(len_and_sockaddr *lsa)
 	setsockopt_SOL_SOCKET_int(pingsock, SO_RCVBUF, sockopt);
 
 	sockopt = offsetof(struct icmp6_hdr, icmp6_cksum);
-	if (offsetof(struct icmp6_hdr, icmp6_cksum) != 2)
-		BUG_bad_offsetof_icmp6_cksum();
+	BUILD_BUG_ON(offsetof(struct icmp6_hdr, icmp6_cksum) != 2);
 	setsockopt_int(pingsock, SOL_RAW, IPV6_CHECKSUM, sockopt);
 
 	/* request ttl info to be returned in ancillary data */
diff --git a/networking/tc.c b/networking/tc.c
index 76e2e8359..6d1fef993 100644
--- a/networking/tc.c
+++ b/networking/tc.c
@@ -64,15 +64,14 @@ struct globals {
 	uint32_t filter_proto;
 } FIX_ALIASING;
 #define G (*(struct globals*)&bb_common_bufsiz1)
-struct BUG_G_too_big {
-	char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
-};
 #define filter_ifindex (G.filter_ifindex)
 #define filter_qdisc (G.filter_qdisc)
 #define filter_parent (G.filter_parent)
 #define filter_prio (G.filter_prio)
 #define filter_proto (G.filter_proto)
-#define INIT_G() do { } while (0)
+#define INIT_G() do { \
+	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
+} while (0)
 
 /* Allocates a buffer containing the name of a class id.
  * The caller must free the returned memory.  */
diff --git a/networking/tftp.c b/networking/tftp.c
index 8ecd7bb6f..ad9308e52 100644
--- a/networking/tftp.c
+++ b/networking/tftp.c
@@ -129,10 +129,9 @@ struct globals {
 #endif
 } FIX_ALIASING;
 #define G (*(struct globals*)&bb_common_bufsiz1)
-struct BUG_G_too_big {
-	char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
-};
-#define INIT_G() do { } while (0)
+#define INIT_G() do { \
+	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
+} while (0)
 
 #define G_error_pkt_reason (G.error_pkt[3])
 #define G_error_pkt_str    ((char*)(G.error_pkt + 4))