[Qemu-devel] [PATCH V2 4/5] util: add new function message_printf()

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

This function takes an input parameter *output, which can be specified by
caller as stderr, stdout or a monitor. error_vprintf() now calls message_vprintf(),
which is a static function added in this patch.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
---
 include/qemu/error-report.h |   13 +++++++++++++
 util/qemu-error.c           |   28 ++++++++++++++++++++++++++--
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/include/qemu/error-report.h b/include/qemu/error-report.h
index c902cc1..cdde78b 100644
--- a/include/qemu/error-report.h
+++ b/include/qemu/error-report.h
@@ -14,6 +14,8 @@
 #define QEMU_ERROR_H
 
 #include <stdarg.h>
+#include <stdio.h>
+#include "qemu/typedefs.h"
 
 typedef struct Location {
     /* all members are private to qemu-error.c */
@@ -32,6 +34,17 @@ void loc_set_none(void);
 void loc_set_cmdline(char **argv, int idx, int cnt);
 void loc_set_file(const char *fname, int lno);
 
+typedef struct QemuOutput {
+    enum { OUTPUT_STREAM, OUTPUT_MONITOR } kind;
+    union {
+        FILE *stream;
+        Monitor *monitor;
+    };
+} QemuOutput;
+
+void message_printf(const QemuOutput *output, const char *fmt, ...)
+                    GCC_FMT_ATTR(2, 3);
+
 void error_vprintf(const char *fmt, va_list ap) GCC_FMT_ATTR(1, 0);
 void error_printf(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
 void error_printf_unless_qmp(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
diff --git a/util/qemu-error.c b/util/qemu-error.c
index 08a36f4..c7ff0a8 100644
--- a/util/qemu-error.c
+++ b/util/qemu-error.c
@@ -13,6 +13,25 @@
 #include <stdio.h>
 #include "monitor/monitor.h"
 
+static GCC_FMT_ATTR(2, 0)
+void message_vprintf(const QemuOutput *output, const char *fmt, va_list ap)
+{
+    if (output->kind == OUTPUT_STREAM) {
+        vfprintf(output->stream, fmt, ap);
+    } else if (output->kind == OUTPUT_MONITOR) {
+        monitor_vprintf(output->monitor, fmt, ap);
+    }
+}
+
+void message_printf(const QemuOutput *output, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    message_vprintf(output, fmt, ap);
+    va_end(ap);
+}
+
 /*
  * Print to current monitor if we have one, else to stderr.
  * TODO should return int, so callers can calculate width, but that
@@ -20,11 +39,16 @@
  */
 void error_vprintf(const char *fmt, va_list ap)
 {
+    QemuOutput output;
+
     if (cur_mon) {
-        monitor_vprintf(cur_mon, fmt, ap);
+        output.kind = OUTPUT_MONITOR;
+        output.monitor = cur_mon;
     } else {
-        vfprintf(stderr, fmt, ap);
+        output.kind = OUTPUT_STREAM;
+        output.stream = stderr;
     }
+    message_vprintf(&output, fmt, ap);
 }
 
 /*
-- 
1.7.1