From: Alejandro Colomar <alx@kernel.org>
Date: Wed, 23 Jul 2025 12:23:11 +0000 (+0200)
Subject: lib/io/syslog.h: SYSLOGE[C](): Add macros
X-Git-Tag: 4.20.0-rc3~26
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b4adbe6387ae8d95dbe0bd547a157492842bea12;p=thirdparty%2Fshadow.git

lib/io/syslog.h: SYSLOGE[C](): Add macros

like the fprintf(3) wrappers, these print an error message.  SYSLOGE()
uses errno, and SYSLOGEC() uses an errno-like error code.

This time we need to be careful to name the local copy of errno
differently than within SYSLOG() --which we call--.  Let's use a double
underscore.  In the future, C might have function literals (similar to
lambdas), which will solve this issue.

Signed-off-by: Alejandro Colomar <alx@kernel.org>
---

diff --git a/lib/io/syslog.h b/lib/io/syslog.h
index 323941c70..8a3ea4556 100644
--- a/lib/io/syslog.h
+++ b/lib/io/syslog.h
@@ -8,6 +8,7 @@
 
 #include "config.h"
 
+#include <errno.h>
 #include <locale.h>
 #include <stddef.h>
 #include <stdlib.h>
@@ -56,6 +57,24 @@
 #define OPENLOG(progname) openlog(progname, SYSLOG_OPTIONS, SYSLOG_FACILITY)
 
 
+// SYSLOGE - system log errno
+#define SYSLOGE(prio, fmt, ...)  do                                   \
+{                                                                     \
+	int  e__;                                                     \
+                                                                      \
+	e__ = errno;                                                  \
+	SYSLOGEC(prio, e__, fmt __VA_OPT__(,) __VA_ARGS__);           \
+	errno = e__;                                                  \
+} while (0)
+
+
+// SYSLOGEC - system log errno code
+#define SYSLOGEC(prio, e, fmt, ...)  do                               \
+{                                                                     \
+	SYSLOG(prio, "" fmt ": %s" __VA_OPT__(,) __VA_ARGS__, strerror(e)); \
+} while (0)
+
+
 // system log C-locale
 #define SYSLOG_C(...)  do                                             \
 {                                                                     \