Add two functions to print an error/warning report once depending
on a passed-in condition variable and flip it if printed. This is
useful if you want to print a message not once-globally, but e.g.
once-per-device.
Inspired by warn_once() in hw/vfio/ccw.c.
Signed-off-by: Cornelia Huck <coh...@redhat.com>
---
include/qemu/error-report.h | 5 +++++
util/qemu-error.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 49 insertions(+)
diff --git a/include/qemu/error-report.h b/include/qemu/error-report.h
index 72fab2b031..d2a6515e68 100644
--- a/include/qemu/error-report.h
+++ b/include/qemu/error-report.h
@@ -44,6 +44,11 @@ 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);
+void error_report_once_cond(bool *printed, const char *fmt, ...)
+ GCC_FMT_ATTR(2, 3);
+void warn_report_once_cond(bool *printed, const char *fmt, ...)
+ GCC_FMT_ATTR(2, 3);
+
/*
* Similar to error_report(), except it prints the message just once.
* Return true when it prints, false otherwise.
diff --git a/util/qemu-error.c b/util/qemu-error.c
index a25d3b94c6..0894ab6995 100644
--- a/util/qemu-error.c
+++ b/util/qemu-error.c
@@ -310,3 +310,47 @@ void info_report(const char *fmt, ...)
vreport(REPORT_TYPE_INFO, fmt, ap);
va_end(ap);
}
+
+/*
+ * If *printed is false, print an error message to current monitor if we
+ * have one, else to stderr, and flip *printed to true.
+ * If printed is NULL, do not print anything.
+ * 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 error_report_once_cond(bool *printed, const char *fmt, ...)
+{
+ va_list ap;
+
+ if (!printed || *printed) {
+ return;
+ }
+ *printed = true;
+ va_start(ap, fmt);
+ vreport(REPORT_TYPE_ERROR, fmt, ap);
+ va_end(ap);
+}
+
+/*
+ * If *printed is false, print a warning message to current monitor if we
+ * have one, else to stderr, and flip *printed to true.
+ * If printed is NULL, do not print anything.
+ * 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 warn_report_once_cond(bool *printed, const char *fmt, ...)
+{
+ va_list ap;
+
+ if (!printed || *printed) {
+ return;
+ }
+ *printed = true;
+ va_start(ap, fmt);
+ vreport(REPORT_TYPE_WARNING, fmt, ap);
+ va_end(ap);
+}
--
2.14.4
