meson, ops: define sd_event ops by intent, not libsystemd presence

Setting HAVE_LIBSYSTEMD based on target is a bit misleading: we may
*have* a libsystemd available, but not want to use it (for example, in
ops used by the mctp binary).

Instead, use OPS_SD_EVENT to describe our intent to include the sd_event
operations.

Signed-off-by: Jeremy Kerr <[email protected]>

Author: jk-ozlabs

meson.build

@@ -60,13 +60,11 @@ toml_dep = declare_dependency(
 executable('mctp',
     sources: ['src/mctp.c'] + netlink_sources + util_sources + ops_sources,
     install: true,
-    c_args: ['-DHAVE_LIBSYSTEMD=0'],
 )
 
 mctp_test = executable('test-mctp',
     sources: ['src/mctp.c'] + netlink_sources + util_sources + test_ops_sources,
     include_directories:  include_directories('src'),
-    c_args: ['-DHAVE_LIBSYSTEMD=0'],
 )
 
 executable('mctp-req',
@@ -94,7 +92,7 @@ if libsystemd.found()
         dependencies: [libsystemd, toml_dep],
         install: true,
         install_dir: get_option('sbindir'),
-        c_args: ['-DHAVE_LIBSYSTEMD=1'],
+        c_args: ['-DOPS_SD_EVENT=1'],
     )
 
     mctpd_test = executable('test-mctpd',
@@ -103,7 +101,7 @@ if libsystemd.found()
         ] + test_ops_sources + netlink_sources + util_sources,
         include_directories:  include_directories('src'),
         dependencies: [libsystemd, toml_dep],
-        c_args: ['-DHAVE_LIBSYSTEMD=1'],
+        c_args: ['-DOPS_SD_EVENT=1'],
     )
 endif
 

src/mctp-ops.c

@@ -9,9 +9,6 @@
 
 #include <unistd.h>
 #include <linux/netlink.h>
-#if HAVE_LIBSYSTEMD
-#include <systemd/sd-event.h>
-#endif
 #include <err.h>
 
 #include "mctp.h"
@@ -77,7 +74,7 @@ const struct mctp_ops mctp_ops = {
 		.recvfrom = mctp_op_recvfrom,
 		.close = mctp_op_close,
 	},
-#if HAVE_LIBSYSTEMD
+#if OPS_SD_EVENT
 	.sd_event = {
 		.add_time_relative = sd_event_add_time_relative,
 		.source_set_time_relative = sd_event_source_set_time_relative,

src/mctp-ops.h

@@ -9,7 +9,7 @@
 
 #include <sys/socket.h>
 #include <stdarg.h>
-#if HAVE_LIBSYSTEMD
+#if OPS_SD_EVENT
 #include <systemd/sd-event.h>
 #endif
 
@@ -27,7 +27,7 @@ struct socket_ops {
 	int (*close)(int sd);
 };
 
-#if HAVE_LIBSYSTEMD
+#if OPS_SD_EVENT
 struct sd_event_ops {
 	typeof(sd_event_add_time_relative) *add_time_relative;
 	typeof(sd_event_source_set_time_relative) *source_set_time_relative;
@@ -37,7 +37,7 @@ struct sd_event_ops {
 struct mctp_ops {
 	struct socket_ops mctp;
 	struct socket_ops nl;
-#if HAVE_LIBSYSTEMD
+#if OPS_SD_EVENT
 	struct sd_event_ops sd_event;
 #endif
 	void (*bug_warn)(const char *fmt, va_list args);

tests/mctp-ops-test.c

@@ -19,9 +19,6 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 
-#if HAVE_LIBSYSTEMD
-#include <systemd/sd-event.h>
-#endif
 #include <linux/netlink.h>
 
 #include "mctp-ops.h"
@@ -227,7 +224,7 @@ static void mctp_bug_warn(const char *fmt, va_list args)
 	abort();
 }
 
-#if HAVE_LIBSYSTEMD
+#if OPS_SD_EVENT
 struct wrapped_time_userdata {
 	sd_event_time_handler_t callback;
 	void *userdata;
@@ -353,7 +350,7 @@ const struct mctp_ops mctp_ops = {
 		.recvfrom = mctp_op_recvfrom,
 		.close = mctp_op_close,
 	},
-#if HAVE_LIBSYSTEMD
+#if OPS_SD_EVENT
 	.sd_event = {
 		.add_time_relative = mctp_op_sd_event_add_time_relative,
 		.source_set_time_relative = mctp_op_sd_event_source_set_time_relative,