Use c99 static array size declarations in exported functions too

keszybz · keszybz · commit 4199f6896aee · 2019-01-04T12:37:25.000+01:00
It seems quite useful to provide this additional information in public exported
functions.

This is a c99 feature, not supported in C++. Without the check in _sd-common.h:
FAILED: test-bus-vtable-cc@exe/src_libsystemd_sd-bus_test-bus-vtable-cc.cc.o
...
In file included from ../src/libsystemd/sd-bus/test-bus-vtable-cc.cc:9:
In file included from ../src/systemd/sd-bus-vtable.h:26:
In file included from ../src/systemd/sd-bus.h:26:
../src/systemd/sd-id128.h:38:47: error: static array size is a C99 feature, not permitted in C++
char *sd_id128_to_string(sd_id128_t id, char s[static SD_ID128_STRING_MAX]);
                                              ^

In .c files, I opted to use the define for consistency, even though we don't support
compilation with a C++ compiler, so the unconditional keyword would work too.
diff --git a/src/libsystemd-network/lldp-neighbor.c b/src/libsystemd-network/lldp-neighbor.c
@@ -691,7 +691,7 @@ _public_ int sd_lldp_neighbor_tlv_is_type(sd_lldp_neighbor *n, uint8_t type) {
         return type == k;
 }
 
-_public_ int sd_lldp_neighbor_tlv_get_oui(sd_lldp_neighbor *n, uint8_t oui[3], uint8_t *subtype) {
+_public_ int sd_lldp_neighbor_tlv_get_oui(sd_lldp_neighbor *n, uint8_t oui[_SD_ARRAY_STATIC 3], uint8_t *subtype) {
         const uint8_t *d;
         size_t length;
         int r;
@@ -720,7 +720,7 @@ _public_ int sd_lldp_neighbor_tlv_get_oui(sd_lldp_neighbor *n, uint8_t oui[3], u
         return 0;
 }
 
-_public_ int sd_lldp_neighbor_tlv_is_oui(sd_lldp_neighbor *n, const uint8_t oui[3], uint8_t subtype) {
+_public_ int sd_lldp_neighbor_tlv_is_oui(sd_lldp_neighbor *n, const uint8_t oui[_SD_ARRAY_STATIC 3], uint8_t subtype) {
         uint8_t k[3], st;
         int r;
 
diff --git a/src/libsystemd/sd-id128/sd-id128.c b/src/libsystemd/sd-id128/sd-id128.c
@@ -18,7 +18,7 @@
 #include "user-util.h"
 #include "util.h"
 
-_public_ char *sd_id128_to_string(sd_id128_t id, char s[SD_ID128_STRING_MAX]) {
+_public_ char *sd_id128_to_string(sd_id128_t id, char s[_SD_ARRAY_STATIC SD_ID128_STRING_MAX]) {
         unsigned n;
 
         assert_return(s, NULL);
diff --git a/src/systemd/_sd-common.h b/src/systemd/_sd-common.h
@@ -72,6 +72,14 @@ typedef void (*_sd_destroy_t)(void *userdata);
 #  endif
 #endif
 
+#ifndef _SD_ARRAY_STATIC
+#  if __STDC_VERSION__ >= 199901L
+#    define _SD_ARRAY_STATIC static
+#  else
+#    define _SD_ARRAY_STATIC
+#  endif
+#endif
+
 #define _SD_DEFINE_POINTER_CLEANUP_FUNC(type, func)             \
         static __inline__ void func##p(type **p) {              \
                 if (*p)                                         \
diff --git a/src/systemd/sd-id128.h b/src/systemd/sd-id128.h
@@ -35,7 +35,7 @@ union sd_id128 {
 
 #define SD_ID128_STRING_MAX 33
 
-char *sd_id128_to_string(sd_id128_t id, char s[SD_ID128_STRING_MAX]);
+char *sd_id128_to_string(sd_id128_t id, char s[_SD_ARRAY_STATIC SD_ID128_STRING_MAX]);
 int sd_id128_from_string(const char *s, sd_id128_t *ret);
 
 int sd_id128_randomize(sd_id128_t *ret);
diff --git a/src/systemd/sd-lldp.h b/src/systemd/sd-lldp.h
@@ -168,8 +168,8 @@ int sd_lldp_neighbor_tlv_rewind(sd_lldp_neighbor *n);
 int sd_lldp_neighbor_tlv_next(sd_lldp_neighbor *n);
 int sd_lldp_neighbor_tlv_get_type(sd_lldp_neighbor *n, uint8_t *type);
 int sd_lldp_neighbor_tlv_is_type(sd_lldp_neighbor *n, uint8_t type);
-int sd_lldp_neighbor_tlv_get_oui(sd_lldp_neighbor *n, uint8_t oui[3], uint8_t *subtype);
-int sd_lldp_neighbor_tlv_is_oui(sd_lldp_neighbor *n, const uint8_t oui[3], uint8_t subtype);
+int sd_lldp_neighbor_tlv_get_oui(sd_lldp_neighbor *n, uint8_t oui[_SD_ARRAY_STATIC 3], uint8_t *subtype);
+int sd_lldp_neighbor_tlv_is_oui(sd_lldp_neighbor *n, const uint8_t oui[_SD_ARRAY_STATIC 3], uint8_t subtype);
 int sd_lldp_neighbor_tlv_get_raw(sd_lldp_neighbor *n, const void **ret, size_t *size);
 
 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_lldp, sd_lldp_unref);

Original file line number	Diff line number	Diff line change
`@@ -691,7 +691,7 @@ _public_ int sd_lldp_neighbor_tlv_is_type(sd_lldp_neighbor *n, uint8_t type) {`
`691`	`691`	`return type == k;`
`692`	`692`	`}`
`693`	`693`
`694`		`-_public_ int sd_lldp_neighbor_tlv_get_oui(sd_lldp_neighbor n, uint8_t oui[3], uint8_t subtype) {`
	`694`	`+_public_ int sd_lldp_neighbor_tlv_get_oui(sd_lldp_neighbor n, uint8_t oui[_SD_ARRAY_STATIC 3], uint8_t subtype) {`
`695`	`695`	`const uint8_t *d;`
`696`	`696`	`size_t length;`
`697`	`697`	`int r;`
`@@ -720,7 +720,7 @@ _public_ int sd_lldp_neighbor_tlv_get_oui(sd_lldp_neighbor *n, uint8_t oui[3], u`
`720`	`720`	`return 0;`
`721`	`721`	`}`
`722`	`722`
`723`		`-_public_ int sd_lldp_neighbor_tlv_is_oui(sd_lldp_neighbor *n, const uint8_t oui[3], uint8_t subtype) {`
	`723`	`+_public_ int sd_lldp_neighbor_tlv_is_oui(sd_lldp_neighbor *n, const uint8_t oui[_SD_ARRAY_STATIC 3], uint8_t subtype) {`
`724`	`724`	`uint8_t k[3], st;`
`725`	`725`	`int r;`
`726`	`726`