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, 11 insertions, 11 deletions

diff --git a/networking/wget.c b/networking/wget.c
index b6f9d605a..9e5a40b6f 100644
--- a/networking/wget.c
+++ b/networking/wget.c
@@ -368,7 +368,7 @@ static void alarm_handler(int sig UNUSED_PARAM)
 {
         /* This is theoretically unsafe (uses stdio and malloc in signal handler) */
         if (G.die_if_timed_out)
-                bb_error_msg_and_die("download timed out");
+                bb_simple_error_msg_and_die("download timed out");
 }
 static void set_alarm(void)
 {
@@ -452,7 +452,7 @@ static char fgets_trim_sanitize(FILE *fp, const char *fmt)
 
         set_alarm();
         if (fgets(G.wget_buf, sizeof(G.wget_buf), fp) == NULL)
-                bb_perror_msg_and_die("error getting response");
+                bb_simple_perror_msg_and_die("error getting response");
         clear_alarm();
 
         buf_ptr = strchrnul(G.wget_buf, '\n');
@@ -633,7 +633,7 @@ static char *get_sanitized_hdr(FILE *fp)
 
 static void reset_beg_range_to_zero(void)
 {
-        bb_error_msg("restart failed");
+        bb_simple_error_msg("restart failed");
         G.beg_range = 0;
         xlseek(G.output_fd, 0, SEEK_SET);
         /* Done at the end instead: */
@@ -651,7 +651,7 @@ static int spawn_https_helper_openssl(const char *host, unsigned port)
 
         if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) != 0)
                 /* Kernel can have AF_UNIX support disabled */
-                bb_perror_msg_and_die("socketpair");
+                bb_simple_perror_msg_and_die("socketpair");
 
         if (!strchr(host, ':'))
                 host = allocated = xasprintf("%s:%u", host, port);
@@ -724,7 +724,7 @@ static void spawn_ssl_client(const char *host, int network_fd, int flags)
 
         if (!(option_mask32 & WGET_OPT_NO_CHECK_CERT)) {
                 option_mask32 |= WGET_OPT_NO_CHECK_CERT;
-                bb_error_msg("note: TLS certificate validation not implemented");
+                bb_simple_error_msg("note: TLS certificate validation not implemented");
         }
 
         servername = xstrdup(host);
@@ -733,7 +733,7 @@ static void spawn_ssl_client(const char *host, int network_fd, int flags)
 
         if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) != 0)
                 /* Kernel can have AF_UNIX support disabled */
-                bb_perror_msg_and_die("socketpair");
+                bb_simple_perror_msg_and_die("socketpair");
 
         fflush_all();
         pid = BB_MMU ? xfork() : xvfork();
@@ -785,7 +785,7 @@ static FILE* prepare_ftp_session(FILE **dfpp, struct host_info *target, len_and_
 #endif
 
         if (ftpcmd(NULL, NULL, sfp) != 220)
-                bb_error_msg_and_die("%s", G.wget_buf);
+                bb_simple_error_msg_and_die(G.wget_buf);
                 /* note: ftpcmd() sanitizes G.wget_buf, ok to print */
 
         /* Split username:password pair */
@@ -948,7 +948,7 @@ static void NOINLINE retrieve_file_data(FILE *dfp)
                         if (errno != EAGAIN) {
                                 if (ferror(dfp)) {
                                         progress_meter(PROGRESS_END);
-                                        bb_perror_msg_and_die(bb_msg_read_error);
+                                        bb_simple_perror_msg_and_die(bb_msg_read_error);
                                 }
                                 break; /* EOF, not error */
                         }
@@ -961,7 +961,7 @@ static void NOINLINE retrieve_file_data(FILE *dfp)
 # if ENABLE_FEATURE_WGET_TIMEOUT
                                 if (second_cnt != 0 && --second_cnt == 0) {
                                         progress_meter(PROGRESS_END);
-                                        bb_error_msg_and_die("download timed out");
+                                        bb_simple_error_msg_and_die("download timed out");
                                 }
 # endif
                                 /* We used to loop back to poll here,
@@ -1014,7 +1014,7 @@ static void NOINLINE retrieve_file_data(FILE *dfp)
         G.got_clen = 1; /* makes it show 100% even for download of (formerly) unknown size */
         progress_meter(PROGRESS_END);
         if (G.content_len != 0) {
-                bb_perror_msg_and_die("connection closed prematurely");
+                bb_simple_perror_msg_and_die("connection closed prematurely");
                 /* GNU wget says "DATE TIME (NN MB/s) - Connection closed at byte NNN. Retrying." */
         }
 
@@ -1348,7 +1348,7 @@ However, in real world it was observed that some web servers
                         }
                         if (key == KEY_location && status >= 300) {
                                 if (--redir_limit == 0)
-                                        bb_error_msg_and_die("too many redirections");
+                                        bb_simple_error_msg_and_die("too many redirections");
                                 fclose(sfp);
                                 if (str[0] == '/') {
                                         free(redirected_path);