Use c99 static array size declarations in exported functions too

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.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/systemd/_sd-common.h b/src/systemd/_sd-common.h
index 05c38008cf..b3ee7bbc24 100644
--- 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)                                         \