[PATCH v4 2/9] add die() to log an error message and exit with a single call

[Laine Stump <laine@redhat.com>]

Almost all occurences of err() are either immediately followed by
exit(EXIT_FAILURE), usage(argv[0]) (which itself then calls
exit(EXIT_FAILURE), or that is what's done immediately after returning
from the function that calls err(). Modify the errfn macro so that its
instantiations can include exit(EXIT_FAILURE) at the end, and use that
to create a new function die() that will log an error and then
exit.

Signed-off-by: Laine Stump <laine@redhat.com>
---
 log.c | 14 +++++++++-----
 log.h |  1 +
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/log.c b/log.c
index 6dc6673..2920aba 100644
--- a/log.c
+++ b/log.c
@@ -44,7 +44,7 @@ static char	log_header[BUFSIZ];	/* File header, written back on cuts */
 static time_t	log_start;		/* Start timestamp */
 int		log_trace;		/* --trace mode enabled */
 
-#define logfn(name, level)						\
+#define logfn(name, level, doexit)					\
 void name(const char *format, ...) {					\
 	struct timespec tp;						\
 	va_list args;							\
@@ -74,6 +74,9 @@ void name(const char *format, ...) {					\
 		if (format[strlen(format)] != '\n')			\
 			fprintf(stderr, "\n");				\
 	}								\
+									\
+	if (doexit)							\
+		exit(EXIT_FAILURE);					\
 }
 
 /* Prefixes for log file messages, indexed by priority */
@@ -86,10 +89,11 @@ const char *logfile_prefix[] = {
 	"         ",		/* LOG_DEBUG */
 };
 
-logfn(err,   LOG_ERR)
-logfn(warn,  LOG_WARNING)
-logfn(info,  LOG_INFO)
-logfn(debug, LOG_DEBUG)
+logfn(die,  LOG_ERR,     1)
+logfn(err,  LOG_ERR,     0)
+logfn(warn, LOG_WARNING, 0)
+logfn(info, LOG_INFO,    0)
+logfn(debug,LOG_DEBUG,   0)
 
 /**
  * trace_init() - Set log_trace depending on trace (debug) mode
diff --git a/log.h b/log.h
index 987dc17..d4e9d85 100644
--- a/log.h
+++ b/log.h
@@ -10,6 +10,7 @@
 #define LOGFILE_CUT_RATIO		30	/* When full, cut ~30% size */
 #define LOGFILE_SIZE_MIN		(5UL * MAX(BUFSIZ, PAGE_SIZE))
 
+void die(const char *format, ...);
 void err(const char *format, ...);
 void warn(const char *format, ...);
 void info(const char *format, ...);
-- 
@@ -10,6 +10,7 @@
 #define LOGFILE_CUT_RATIO		30	/* When full, cut ~30% size */
 #define LOGFILE_SIZE_MIN		(5UL * MAX(BUFSIZ, PAGE_SIZE))
 
+void die(const char *format, ...);
 void err(const char *format, ...);
 void warn(const char *format, ...);
 void info(const char *format, ...);
-- 
2.39.1