build: Define DBUS_INT64_MODIFIER, analogous to G_GINT64_MODIFIER

Using PRId64, etc. to print dbus_int64_t or dbus_uint64_t is not 100%
portable. On platforms where both long and long long are 64-bit (such as
Linux and macOS), we will prefer to define dbus_int64_t as long.
If the operating system has chosen to define int64_t as long long,
which is apparently the case on macOS, then the compiler can warn that
we are passing a long argument to PRId64, which is "lld" and therefore
expects a long long argument (even though that ends up with the same
bit-pattern being used).

We can't necessarily just use int64_t and uint64_t directly, even if all
our supported platforms have them available now, because swapping
dbus_int64_t between long and long long might change C++ name mangling,
causing ABI breaks in third-party libraries if they define C++ functions
that take a dbus_int64_t argument.

Signed-off-by: Simon McVittie <smcv@collabora.com>

1 files changed, 2 insertions, 11 deletions

diff --git a/tools/dbus-print-message.c b/tools/dbus-print-message.c
index 2ce7f68b..22ee6824 100644
--- a/tools/dbus-print-message.c
+++ b/tools/dbus-print-message.c
@@ -43,15 +43,6 @@
 #include <inttypes.h>
 #endif
 
-#if defined(DBUS_WIN)
-#if !defined(PRId64)
-#define PRId64 "I64d"
-#endif
-#if !defined(PRIu64)
-#define PRIu64 "I64u"
-#endif
-#endif
-
 #ifndef HAVE_SOCKLEN_T
 #define socklen_t int
 #endif
@@ -401,7 +392,7 @@ print_iter (DBusMessageIter *iter, dbus_bool_t literal, int depth)
           {
             dbus_int64_t val;
             dbus_message_iter_get_basic (iter, &val);
-            printf ("int64 %" PRId64 "\n", val);
+            printf ("int64 %" DBUS_INT64_MODIFIER "d\n", val);
             break;
           }
 
@@ -409,7 +400,7 @@ print_iter (DBusMessageIter *iter, dbus_bool_t literal, int depth)
           {
             dbus_uint64_t val;
             dbus_message_iter_get_basic (iter, &val);
-            printf ("uint64 %" PRIu64 "\n", val);
+            printf ("uint64 %" DBUS_INT64_MODIFIER "u\n", val);
             break;
           }