[PATCH v4 19/23] util: convert error-report & log to message API for timestamp

["Daniel P. Berrangé" <berrange@redhat.com>]

Both the error-report and log APIs can optional emit a timestamp
as a prefix on messages, with the '-msg timestamp=on' command
line flag is set.

Convert them to the new message API for formatting the context
prefix, guaranteeing they will have matching behaviour going
forward.

There is no change in output format for either logs or errors
with this conversion. There is a slight impact on logging code
in that recording the timestamp is now potentially delayed by
the need to acquire the logging mutex.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 include/qemu/error-report.h    |  1 -
 system/vl.c                    |  7 ++++++-
 tests/unit/test-error-report.c |  3 ++-
 util/error-report.c            | 18 ++----------------
 util/log.c                     | 21 ++++-----------------
 5 files changed, 14 insertions(+), 36 deletions(-)

diff --git a/include/qemu/error-report.h b/include/qemu/error-report.h
index 3ae2357fda..c8000778ec 100644
--- a/include/qemu/error-report.h
+++ b/include/qemu/error-report.h
@@ -70,7 +70,6 @@ void error_init(const char *argv0);
                               fmt, ##__VA_ARGS__);      \
     })
 
-extern bool message_with_timestamp;
 extern bool error_with_guestname;
 extern const char *error_guest_name;
 
diff --git a/system/vl.c b/system/vl.c
index e0884c1bb9..12bfdb3431 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -26,6 +26,7 @@
 #include "qemu/help-texts.h"
 #include "qemu/datadir.h"
 #include "qemu/units.h"
+#include "qemu/message.h"
 #include "qemu/module.h"
 #include "qemu/target-info.h"
 #include "exec/cpu-common.h"
@@ -814,8 +815,12 @@ static void realtime_init(void)
 
 static void configure_msg(QemuOpts *opts)
 {
-    message_with_timestamp = qemu_opt_get_bool(opts, "timestamp", false);
+    int flags = 0;
+    if (qemu_opt_get_bool(opts, "timestamp", false)) {
+        flags |= QMESSAGE_FORMAT_TIMESTAMP;
+    }
     error_with_guestname = qemu_opt_get_bool(opts, "guest-name", false);
+    qmessage_set_format(flags);
 }
 
 
diff --git a/tests/unit/test-error-report.c b/tests/unit/test-error-report.c
index 54319c86c9..78f8b57660 100644
--- a/tests/unit/test-error-report.c
+++ b/tests/unit/test-error-report.c
@@ -13,6 +13,7 @@
 
 #include "qemu/error-report.h"
 #include "qapi/error.h"
+#include "qemu/message.h"
 
 static void
 test_error_report_simple(void)
@@ -90,7 +91,7 @@ static void
 test_error_report_timestamp(void)
 {
     if (g_test_subprocess()) {
-        message_with_timestamp = true;
+        qmessage_set_format(QMESSAGE_FORMAT_TIMESTAMP);
         warn_report("warn");
         error_report("err");
         return;
diff --git a/util/error-report.c b/util/error-report.c
index b6aa20dbae..c1146ba553 100644
--- a/util/error-report.c
+++ b/util/error-report.c
@@ -13,6 +13,7 @@
 #include "qemu/osdep.h"
 #include "monitor/monitor.h"
 #include "qemu/error-report.h"
+#include "qemu/message.h"
 
 /*
  * @report_type is the type of message: error, warning or
@@ -24,8 +25,6 @@ typedef enum {
     REPORT_TYPE_INFO,
 } report_type;
 
-/* Prepend timestamp to messages */
-bool message_with_timestamp;
 bool error_with_guestname;
 const char *error_guest_name;
 
@@ -204,13 +203,6 @@ static void print_loc(Monitor *cur)
     }
 }
 
-static char *
-real_time_iso8601(void)
-{
-    g_autoptr(GDateTime) dt = g_date_time_new_now_utc();
-    return g_date_time_format_iso8601(dt);
-}
-
 /*
  * Print a message to current monitor if we have one, else to stderr.
  * @report_type is the type of message: error, warning or informational.
@@ -222,18 +214,12 @@ G_GNUC_PRINTF(2, 0)
 static void vreport(report_type type, const char *fmt, va_list ap)
 {
     Monitor *cur = NULL;
-    gchar *timestr;
 
     if (monitor_cur_is_hmp()) {
         cur = monitor_cur();
     } else {
         flockfile(stderr);
-    }
-
-    if (message_with_timestamp && !cur) {
-        timestr = real_time_iso8601();
-        error_printf_mon(NULL, "%s ", timestr);
-        g_free(timestr);
+        qmessage_context_print(stderr);
     }
 
     /* Only prepend guest name if -msg guest-name and -name guest=... are set */
diff --git a/util/log.c b/util/log.c
index 2642a55c59..baa33ad8f1 100644
--- a/util/log.c
+++ b/util/log.c
@@ -22,6 +22,7 @@
 #include "qemu/range.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
+#include "qemu/message.h"
 #include "qemu/cutils.h"
 #include "trace/control.h"
 #include "qemu/thread.h"
@@ -151,26 +152,12 @@ static __thread bool incomplete;
 
 void qemu_log(const char *fmt, ...)
 {
-    FILE *f;
-    g_autofree const char *timestr = NULL;
-
-    /*
-     * Prepare the timestamp *outside* the logging
-     * lock so it better reflects when the message
-     * was emitted if we are delayed acquiring the
-     * mutex
-     */
-    if (message_with_timestamp && !incomplete) {
-        g_autoptr(GDateTime) dt = g_date_time_new_now_utc();
-        timestr = g_date_time_format_iso8601(dt);
-    }
-
-    f = qemu_log_trylock();
+    FILE *f = qemu_log_trylock();
     if (f) {
         va_list ap;
 
-        if (timestr) {
-            fprintf(f, "%s ", timestr);
+        if (!incomplete) {
+            qmessage_context_print(f);
         }
 
         va_start(ap, fmt);
-- 
2.50.1