[Qemu-devel] [RFC v3 2/3] qemu-error: Implement a more generic error reporting

[Alistair Francis <alistair.francis@xilinx.com>]

This patch converts the existing error_vreport() function into a generic
qmesg_vreport() function that takes an enum describing the
information to be reported.

As part of this change a new qmesg_report() function is added as well with the
same capability.

To maintain full compatibility the original error_report() function is
maintained and no changes to the way errors are printed have been made.
To improve access to the new informaiton and warning options wrapper functions
similar to error_report() have been added for warnings and information
printing.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
---
RFC V3:
 - Change the function and enum names to be more descriptive
 - Add wrapper functions for *_report() and *_vreport()

 include/qemu/error-report.h | 16 +++++++++
 scripts/checkpatch.pl       |  8 ++++-
 util/qemu-error.c           | 80 +++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 100 insertions(+), 4 deletions(-)

diff --git a/include/qemu/error-report.h b/include/qemu/error-report.h
index 3001865896..62fc167ace 100644
--- a/include/qemu/error-report.h
+++ b/include/qemu/error-report.h
@@ -21,6 +21,12 @@ typedef struct Location {
     struct Location *prev;
 } Location;
 
+typedef enum {
+    REPORT_TYPE_ERROR,
+    REPORT_TYPE_WARNING,
+    REPORT_TYPE_INFO,
+} report_type;
+
 Location *loc_push_restore(Location *loc);
 Location *loc_push_none(Location *loc);
 Location *loc_pop(Location *loc);
@@ -30,13 +36,23 @@ void loc_set_none(void);
 void loc_set_cmdline(char **argv, int idx, int cnt);
 void loc_set_file(const char *fname, int lno);
 
+void qmsg_vreport(report_type type, const char *fmt, va_list ap) GCC_FMT_ATTR(2, 0);
+void qmsg_report(report_type type, 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_vprintf_unless_qmp(const char *fmt, va_list ap) GCC_FMT_ATTR(1, 0);
 void error_printf_unless_qmp(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
 void error_set_progname(const char *argv0);
+
 void error_vreport(const char *fmt, va_list ap) GCC_FMT_ATTR(1, 0);
+void warn_vreport(const char *fmt, va_list ap) GCC_FMT_ATTR(1, 0);
+void info_vreport(const char *fmt, va_list ap) GCC_FMT_ATTR(1, 0);
+
 void error_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
+void warn_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
+void info_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
+
 const char *error_get_progname(void);
 extern bool enable_timestamp_msg;
 
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 45027b9281..8b02621739 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2530,8 +2530,14 @@ sub process {
 				error_set|
 				error_prepend|
 				error_reportf_err|
+				qmsg_vreport|
 				error_vreport|
-				error_report}x;
+				warn_vreport|
+				info_vreport|
+				qmsg_report|
+				error_report|
+				warn_report|
+				info_report}x;
 
 	if ($rawline =~ /\b(?:$qemu_error_funcs)\s*\(.*\".*\\n/) {
 		ERROR("Error messages should not contain newlines\n" . $herecurr);
diff --git a/util/qemu-error.c b/util/qemu-error.c
index 1c5e35ecdb..63fdc0e174 100644
--- a/util/qemu-error.c
+++ b/util/qemu-error.c
@@ -179,17 +179,29 @@ static void print_loc(void)
 
 bool enable_timestamp_msg;
 /*
- * Print an error message to current monitor if we have one, else to stderr.
+ * Print a message to current monitor if we have one, else to stderr.
  * Format arguments like vsprintf().  The resulting message should be
  * a single phrase, with no newline or trailing punctuation.
  * Prepend the current location and append a newline.
  * It's wrong to call this in a QMP monitor.  Use error_setg() there.
  */
-void error_vreport(const char *fmt, va_list ap)
+void qmsg_vreport(report_type type, const char *fmt, va_list ap)
 {
     GTimeVal tv;
     gchar *timestr;
 
+    switch (type) {
+    case REPORT_TYPE_ERROR:
+        /* To maintain compatibility we don't add anything here */
+        break;
+    case REPORT_TYPE_WARNING:
+        error_printf("warning: ");
+        break;
+    case REPORT_TYPE_INFO:
+        error_printf("info: ");
+        break;
+    }
+
     if (enable_timestamp_msg && !cur_mon) {
         g_get_current_time(&tv);
         timestr = g_time_val_to_iso8601(&tv);
@@ -204,16 +216,78 @@ void error_vreport(const char *fmt, va_list ap)
 
 /*
  * Print an error message to current monitor if we have one, else to stderr.
+ */
+void error_vreport(const char *fmt, va_list ap)
+{
+    qmsg_vreport(REPORT_TYPE_ERROR, fmt, ap);
+}
+
+/*
+ * Print a warning message to current monitor if we have one, else to stderr.
+ */
+void warn_vreport(const char *fmt, va_list ap)
+{
+    qmsg_vreport(REPORT_TYPE_WARNING, fmt, ap);
+}
+
+/*
+ * Print an information message to current monitor if we have one, else to
+ * stderr.
+ */
+void info_vreport(const char *fmt, va_list ap)
+{
+    qmsg_vreport(REPORT_TYPE_INFO, fmt, ap);
+}
+
+/*
+ * Print a message to current monitor if we have one, else to stderr.
  * Format arguments like sprintf().  The resulting message should be a
  * single phrase, with no newline or trailing punctuation.
  * Prepend the current location and append a newline.
  * It's wrong to call this in a QMP monitor.  Use error_setg() there.
  */
+void qmsg_report(report_type type, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    qmsg_vreport(type, fmt, ap);
+    va_end(ap);
+}
+
+/*
+ * Print an error message to current monitor if we have one, else to stderr.
+ */
 void error_report(const char *fmt, ...)
 {
     va_list ap;
 
     va_start(ap, fmt);
-    error_vreport(fmt, ap);
+    qmsg_vreport(REPORT_TYPE_ERROR, fmt, ap);
+    va_end(ap);
+}
+
+/*
+ * Print a warning message to current monitor if we have one, else to stderr.
+ */
+void warn_report(const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    qmsg_vreport(REPORT_TYPE_WARNING, fmt, ap);
+    va_end(ap);
+}
+
+/*
+ * Print an information message to current monitor if we have one, else to
+ * stderr.
+ */
+void info_report(const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    qmsg_vreport(REPORT_TYPE_INFO, fmt, ap);
     va_end(ap);
 }
-- 
2.11.0