replay: Simplify setting replay blockers

replay_add_blocker() takes an Error *.  All callers pass one created
like this:

    error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED, "some feature");

Folding this into replay_add_blocker() simplifies the callers, losing
a bit of generality we haven't needed in more than six years.

Since there are no other uses of macro QERR_REPLAY_NOT_SUPPORTED,
replace the remaining one by its expansion, and drop the macro.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230207075115.1525-10-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

include/qapi/qmp/qerror.h

@@ -59,9 +59,6 @@
 #define QERR_QGA_COMMAND_FAILED \
     "Guest agent command failed, error was '%s'"
 
-#define QERR_REPLAY_NOT_SUPPORTED \
-    "Record/replay feature is not supported for '%s'"
-
 #define QERR_UNSUPPORTED \
     "this feature or command is not currently supported"
 

include/sysemu/replay.h

@@ -72,7 +72,7 @@ void replay_start(void);
 /*! Closes replay log file and frees other resources. */
 void replay_finish(void);
 /*! Adds replay blocker with the specified error description */
-void replay_add_blocker(Error *reason);
+void replay_add_blocker(const char *feature);
 /* Returns name of the replay log file */
 const char *replay_get_filename(void);
 /*

replay/replay.c

@@ -376,8 +376,12 @@ void replay_finish(void)
     replay_mode = REPLAY_MODE_NONE;
 }
 
-void replay_add_blocker(Error *reason)
+void replay_add_blocker(const char *feature)
 {
+    Error *reason = NULL;
+
+    error_setg(&reason, "Record/replay feature is not supported for '%s'",
+               feature);
     replay_blockers = g_slist_prepend(replay_blockers, reason);
 }
 

replay/stubs-system.c

@@ -12,7 +12,7 @@ void replay_input_sync_event(void)
     qemu_input_event_sync_impl();
 }
 
-void replay_add_blocker(Error *reason)
+void replay_add_blocker(const char *feature)
 {
 }
 void replay_audio_in(size_t *recorded, void *samples, size_t *wpos, size_t size)

softmmu/rtc.c

@@ -152,11 +152,8 @@ void configure_rtc(QemuOpts *opts)
         if (!strcmp(value, "utc")) {
             rtc_base_type = RTC_BASE_UTC;
         } else if (!strcmp(value, "localtime")) {
-            Error *blocker = NULL;
             rtc_base_type = RTC_BASE_LOCALTIME;
-            error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED,
-                      "-rtc base=localtime");
-            replay_add_blocker(blocker);
+            replay_add_blocker("-rtc base=localtime");
         } else {
             rtc_base_type = RTC_BASE_DATETIME;
             configure_rtc_base_datetime(value);

softmmu/vl.c

@@ -1852,9 +1852,7 @@ static void qemu_apply_machine_options(QDict *qdict)
     }
 
     if (current_machine->smp.cpus > 1) {
-        Error *blocker = NULL;
-        error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED, "smp");
-        replay_add_blocker(blocker);
+        replay_add_blocker("smp");
     }
 }
 
@@ -2774,13 +2772,8 @@ void qemu_init(int argc, char **argv)
                 drive_add(IF_PFLASH, -1, optarg, PFLASH_OPTS);
                 break;
             case QEMU_OPTION_snapshot:
-                {
-                    Error *blocker = NULL;
-                    snapshot = 1;
-                    error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED,
-                               "-snapshot");
-                    replay_add_blocker(blocker);
-                }
+                snapshot = 1;
+                replay_add_blocker("-snapshot");
                 break;
             case QEMU_OPTION_numa:
                 opts = qemu_opts_parse_noisily(qemu_find_opts("numa"),