Re: [PATCH] log, conf, tap: Define die() as err() plus exit(), drop cppcheck workarounds

On Mon, Feb 27, 2023 at 11:00:54AM +0100, Stefano Brivio wrote:
...
  If we define die() as a variadic macro, passing
__VA_ARGS__ to err(),
 and calling exit() outside err() itself, we can drop the workarounds
 introduced in commit 36f0199f6ef4 ("conf, tap: Silence two false
 positive invalidFunctionArg from cppcheck").
 
 Suggested-by: David Gibson <david(a)gibson.dropbear.id.au>
 Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> 
Reviewed-by: David Gibson <david(a)gibson.dropbear.id.au>

...
  ---
  conf.c |  3 ---
  log.c  | 14 +++++---------
  log.h  |  7 ++++++-
  tap.c  |  6 +-----
  4 files changed, 12 insertions(+), 18 deletions(-)
 
 diff --git a/conf.c b/conf.c
 index 37f25d6..0e512f4 100644
 --- a/conf.c
 +++ b/conf.c
 @@ -1064,9 +1064,6 @@ static void conf_ugid(char *runas, uid_t *uid, gid_t *gid)
  	if ((fd = open("/proc/self/uid_map", O_RDONLY | O_CLOEXEC)) < 0) {
  		die("Can't determine if we're in init namespace: %s",
  		    strerror(errno));
 -
 -		/* Silence cppcheck's invalidFunctionArg for 'fd' in read() */
 -		return;
  	}
  
  	if (read(fd, buf, BUFSIZ) != sizeof(root_uid_map) ||
 diff --git a/log.c b/log.c
 index bfde6ce..d2f08fa 100644
 --- a/log.c
 +++ b/log.c
 @@ -46,7 +46,7 @@ int		log_trace;		/* --trace mode enabled */
  
  #define BEFORE_DAEMON		(setlogmask(0) == LOG_MASK(LOG_EMERG))
  
 -#define logfn(name, level, doexit)					\
 +#define logfn(name, level)						\
  void name(const char *format, ...) {					\
  	struct timespec tp;						\
  	va_list args;							\
 @@ -75,9 +75,6 @@ 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 */
 @@ -90,11 +87,10 @@ const char *logfile_prefix[] = {
  	"         ",		/* 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)
 +logfn(err,  LOG_ERR)
 +logfn(warn, LOG_WARNING)
 +logfn(info, LOG_INFO)
 +logfn(debug,LOG_DEBUG)
  
  /**
   * trace_init() - Set log_trace depending on trace (debug) mode
 diff --git a/log.h b/log.h
 index d4e9d85..d4ea141 100644
 --- a/log.h
 +++ b/log.h
 @@ -10,12 +10,17 @@
  #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, ...);
  void debug(const char *format, ...);
  
 +#define die(...)							\
 +	do {								\
 +		err(__VA_ARGS__);					\
 +		exit(EXIT_FAILURE);					\
 +	} while (0)
 +
  extern int log_trace;
  void trace_init(int enable);
  #define trace(...)							\
 diff --git a/tap.c b/tap.c
 index d6f962e..88eed88 100644
 --- a/tap.c
 +++ b/tap.c
 @@ -1037,13 +1037,9 @@ static void tap_sock_unix_init(struct ctx *c)
  			snprintf(path, UNIX_PATH_MAX - 1, UNIX_SOCK_PATH, i);
  
  		ex = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0);
 -		if (ex < 0) {
 +		if (ex < 0)
  			die("UNIX domain socket check: %s", strerror(errno));
  
 -			/* Silence cppcheck's invalidFunctionArg for 'ex' */
 -			return;
 -		}
 -
  		ret = connect(ex, (const struct sockaddr *)&addr, sizeof(addr));
  		if (!ret || (errno != ENOENT && errno != ECONNREFUSED &&
  			     errno != EACCES)) { 
-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson