libbb: reduce the overhead of single parameter bb_error_msg() calls

Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by
Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower
overhead call to bb_perror_msg() when only a string was being printed
with no parameters. This saves space for some CPU architectures because
it avoids the overhead of a call to a variadic function. However there
has never been a simple version of bb_error_msg(), and since 2007 many
new calls to bb_perror_msg() have been added that only take a single
parameter and so could have been using bb_simple_perror_message().

This changeset introduces 'simple' versions of bb_info_msg(),
bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and
bb_herror_msg_and_die(), and replaces all calls that only take a
single parameter, or use something like ("%s", arg), with calls to the
corresponding 'simple' version.

Since it is likely that single parameter calls to the variadic functions
may be accidentally reintroduced in the future a new debugging config
option WARN_SIMPLE_MSG has been introduced. This uses some macro magic
which will cause any such calls to generate a warning, but this is
turned off by default to avoid use of the unpleasant macros in normal
circumstances.

This is a large changeset due to the number of calls that have been
replaced. The only files that contain changes other than simple
substitution of function calls are libbb.h, libbb/herror_msg.c,
libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c,
networking/udhcp/common.h and util-linux/mdev.c additonal macros have
been added for logging so that single parameter and multiple parameter
logging variants exist.

The amount of space saved varies considerably by architecture, and was
found to be as follows (for 'defconfig' using GCC 7.4):

Arm:     -92 bytes
MIPS:    -52 bytes
PPC:   -1836 bytes
x86_64: -938 bytes

Note that for the MIPS architecture only an exception had to be made
disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h)
because it made these files larger on MIPS.

Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 18 insertions, 18 deletions

diff --git a/networking/arp.c b/networking/arp.c
index 71bfe3cbf..6519f8156 100644
--- a/networking/arp.c
+++ b/networking/arp.c
@@ -116,7 +116,7 @@ static int arp_del(char **args)
         /* Resolve the host name. */
         host = *args;
         if (ap->input(host, &sa) < 0) {
-                bb_herror_msg_and_die("%s", host);
+                bb_simple_herror_msg_and_die(host);
         }
 
         /* If a host has more than one address, use the correct one! */
@@ -149,7 +149,7 @@ static int arp_del(char **args)
 #ifdef HAVE_ATF_DONTPUB
                         req.arp_flags |= ATF_DONTPUB;
 #else
-                        bb_error_msg("feature ATF_DONTPUB is not supported");
+                        bb_simple_error_msg("feature ATF_DONTPUB is not supported");
 #endif
                         args++;
                         break;
@@ -157,7 +157,7 @@ static int arp_del(char **args)
 #ifdef HAVE_ATF_MAGIC
                         req.arp_flags |= ATF_MAGIC;
 #else
-                        bb_error_msg("feature ATF_MAGIC is not supported");
+                        bb_simple_error_msg("feature ATF_MAGIC is not supported");
 #endif
                         args++;
                         break;
@@ -173,7 +173,7 @@ static int arp_del(char **args)
                         if (strcmp(*args, "255.255.255.255") != 0) {
                                 host = *args;
                                 if (ap->input(host, &sa) < 0) {
-                                        bb_herror_msg_and_die("%s", host);
+                                        bb_simple_herror_msg_and_die(host);
                                 }
                                 memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
                                 req.arp_flags |= ATF_NETMASK;
@@ -195,7 +195,7 @@ static int arp_del(char **args)
         /* Call the kernel. */
         if (flags & 2) {
                 if (option_mask32 & ARP_OPT_v)
-                        bb_error_msg("SIOCDARP(nopub)");
+                        bb_simple_error_msg("SIOCDARP(nopub)");
                 err = ioctl(sockfd, SIOCDARP, &req);
                 if (err < 0) {
                         if (errno == ENXIO) {
@@ -204,20 +204,20 @@ static int arp_del(char **args)
                                 printf("No ARP entry for %s\n", host);
                                 return -1;
                         }
-                        bb_perror_msg_and_die("SIOCDARP(priv)");
+                        bb_simple_perror_msg_and_die("SIOCDARP(priv)");
                 }
         }
         if ((flags & 1) && err) {
  nopub:
                 req.arp_flags |= ATF_PUBL;
                 if (option_mask32 & ARP_OPT_v)
-                        bb_error_msg("SIOCDARP(pub)");
+                        bb_simple_error_msg("SIOCDARP(pub)");
                 if (ioctl(sockfd, SIOCDARP, &req) < 0) {
                         if (errno == ENXIO) {
                                 printf("No ARP entry for %s\n", host);
                                 return -1;
                         }
-                        bb_perror_msg_and_die("SIOCDARP(pub)");
+                        bb_simple_perror_msg_and_die("SIOCDARP(pub)");
                 }
         }
         return 0;
@@ -233,7 +233,7 @@ static void arp_getdevhw(char *ifname, struct sockaddr *sa)
         ioctl_or_perror_and_die(sockfd, SIOCGIFHWADDR, &ifr,
                                         "can't get HW-Address for '%s'", ifname);
         if (hw_set && (ifr.ifr_hwaddr.sa_family != hw->type)) {
-                bb_error_msg_and_die("protocol type mismatch");
+                bb_simple_error_msg_and_die("protocol type mismatch");
         }
         memcpy(sa, &(ifr.ifr_hwaddr), sizeof(struct sockaddr));
 
@@ -261,20 +261,20 @@ static int arp_set(char **args)
 
         host = *args++;
         if (ap->input(host, &sa) < 0) {
-                bb_herror_msg_and_die("%s", host);
+                bb_simple_herror_msg_and_die(host);
         }
         /* If a host has more than one address, use the correct one! */
         memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr));
 
         /* Fetch the hardware address. */
         if (*args == NULL) {
-                bb_error_msg_and_die("need hardware address");
+                bb_simple_error_msg_and_die("need hardware address");
         }
         if (option_mask32 & ARP_OPT_D) {
                 arp_getdevhw(*args++, &req.arp_ha);
         } else {
                 if (hw->input(*args++, &req.arp_ha) < 0) {
-                        bb_error_msg_and_die("invalid hardware address");
+                        bb_simple_error_msg_and_die("invalid hardware address");
                 }
         }
 
@@ -302,7 +302,7 @@ static int arp_set(char **args)
 #ifdef HAVE_ATF_DONTPUB
                         flags |= ATF_DONTPUB;
 #else
-                        bb_error_msg("feature ATF_DONTPUB is not supported");
+                        bb_simple_error_msg("feature ATF_DONTPUB is not supported");
 #endif
                         args++;
                         break;
@@ -310,7 +310,7 @@ static int arp_set(char **args)
 #ifdef HAVE_ATF_MAGIC
                         flags |= ATF_MAGIC;
 #else
-                        bb_error_msg("feature ATF_MAGIC is not supported");
+                        bb_simple_error_msg("feature ATF_MAGIC is not supported");
 #endif
                         args++;
                         break;
@@ -326,7 +326,7 @@ static int arp_set(char **args)
                         if (strcmp(*args, "255.255.255.255") != 0) {
                                 host = *args;
                                 if (ap->input(host, &sa) < 0) {
-                                        bb_herror_msg_and_die("%s", host);
+                                        bb_simple_herror_msg_and_die(host);
                                 }
                                 memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
                                 flags |= ATF_NETMASK;
@@ -346,7 +346,7 @@ static int arp_set(char **args)
 
         /* Call the kernel. */
         if (option_mask32 & ARP_OPT_v)
-                bb_error_msg("SIOCSARP()");
+                bb_simple_error_msg("SIOCSARP()");
         xioctl(sockfd, SIOCSARP, &req);
         return 0;
 }
@@ -422,7 +422,7 @@ static int arp_show(char *name)
         if (name != NULL) {
                 /* Resolve the host name. */
                 if (ap->input(name, &sa) < 0) {
-                        bb_herror_msg_and_die("%s", name);
+                        bb_simple_herror_msg_and_die(name);
                 }
                 host = xstrdup(ap->sprint(&sa, 1));
         }
@@ -530,7 +530,7 @@ int arp_main(int argc UNUSED_PARAM, char **argv)
         /* Now see what we have to do here... */
         if (opts & (ARP_OPT_d | ARP_OPT_s)) {
                 if (argv[0] == NULL)
-                        bb_error_msg_and_die("need host name");
+                        bb_simple_error_msg_and_die("need host name");
                 if (opts & ARP_OPT_s)
                         return arp_set(argv);
                 return arp_del(argv);