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

Back in 2007, commit 0c97c9d ("'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 <[email protected]>
Signed-off-by: Denys Vlasenko <[email protected]>

Config.in

@@ -661,6 +661,19 @@ config WERROR
 
 	Most people should answer N.
 
+config WARN_SIMPLE_MSG
+	bool "Warn about single parameter bb_xx_msg calls"
+	default n
+	help
+	This will cause warnings to be shown for any instances of
+	bb_error_msg(), bb_error_msg_and_die(), bb_perror_msg(),
+	bb_perror_msg_and_die(), bb_herror_msg() or bb_herror_msg_and_die()
+	being called with a single parameter. In these cases the equivalent
+	bb_simple_xx_msg function should be used instead.
+	Note that use of STRERROR_FMT may give false positives.
+
+	If you aren't developing busybox, say N here.
+
 choice
 	prompt "Additional debugging library"
 	default NO_DEBUG_LIB

archival/bbunzip.c

@@ -114,7 +114,7 @@ int FAST_FUNC bbunpack(char **argv,
 
 		/* Check that the input is sane */
 		if (!(option_mask32 & BBUNPK_OPT_FORCE) && isatty(STDIN_FILENO)) {
-			bb_error_msg_and_die("compressed data not read from terminal, "
+			bb_simple_error_msg_and_die("compressed data not read from terminal, "
 					"use -f to force it");
 		}
 

archival/bzip2.c

@@ -145,7 +145,7 @@ IF_DESKTOP(long long) int bz_write(bz_stream *strm, void* rbuf, ssize_t rlen, vo
 			if (n2 != n) {
 				if (n2 >= 0)
 					errno = 0; /* prevent bogus error message */
-				bb_perror_msg(n2 >= 0 ? "short write" : bb_msg_write_error);
+				bb_simple_perror_msg(n2 >= 0 ? "short write" : bb_msg_write_error);
 				return -1;
 			}
 		}
@@ -187,7 +187,7 @@ IF_DESKTOP(long long) int FAST_FUNC compressStream(transformer_state_t *xstate U
 	while (1) {
 		count = full_read(STDIN_FILENO, rbuf, IOBUF_SIZE);
 		if (count < 0) {
-			bb_perror_msg(bb_msg_read_error);
+			bb_simple_perror_msg(bb_msg_read_error);
 			total = -1;
 			break;
 		}

archival/dpkg.c

@@ -487,7 +487,7 @@ static void add_split_dependencies(common_node_t *parent_node, const char *whole
 					} else if (strncmp(version, ">=", offset_ch) == 0) {
 						edge->operator = VER_MORE_EQUAL;
 					} else {
-						bb_error_msg_and_die("illegal operator");
+						bb_simple_error_msg_and_die("illegal operator");
 					}
 				}
 				/* skip to start of version numbers */
@@ -730,7 +730,7 @@ static void set_status(const unsigned status_node_num, const char *new_value, co
 			status = new_value_num;
 			break;
 		default:
-			bb_error_msg_and_die("DEBUG ONLY: this shouldnt happen");
+			bb_simple_error_msg_and_die("DEBUG ONLY: this shouldnt happen");
 	}
 
 	new_status = xasprintf("%s %s %s", name_hashtable[want], name_hashtable[flag], name_hashtable[status]);
@@ -944,10 +944,10 @@ static void write_status_file(deb_file_t **deb_file)
 	/* Create a separate backfile to dpkg */
 	if (rename("/var/lib/dpkg/status", "/var/lib/dpkg/status.udeb.bak") == -1) {
 		if (errno != ENOENT)
-			bb_error_msg_and_die("can't create backup status file");
+			bb_simple_error_msg_and_die("can't create backup status file");
 		/* Its ok if renaming the status file fails because status
 		 * file doesn't exist, maybe we are starting from scratch */
-		bb_error_msg("no status file found, creating new one");
+		bb_simple_error_msg("no status file found, creating new one");
 	}
 
 	xrename("/var/lib/dpkg/status.udeb", "/var/lib/dpkg/status");
@@ -1816,7 +1816,7 @@ int dpkg_main(int argc UNUSED_PARAM, char **argv)
 			init_archive_deb_control(archive_handle);
 			deb_file[deb_count]->control_file = deb_extract_control_file_to_buffer(archive_handle, control_list);
 			if (deb_file[deb_count]->control_file == NULL) {
-				bb_error_msg_and_die("can't extract control file");
+				bb_simple_error_msg_and_die("can't extract control file");
 			}
 			deb_file[deb_count]->filename = xstrdup(argv[0]);
 			package_num = fill_package_struct(deb_file[deb_count]->control_file);
@@ -1879,13 +1879,13 @@ int dpkg_main(int argc UNUSED_PARAM, char **argv)
 		argv++;
 	}
 	if (!deb_count)
-		bb_error_msg_and_die("no package files specified");
+		bb_simple_error_msg_and_die("no package files specified");
 	deb_file[deb_count] = NULL;
 
 	/* Check that the deb file arguments are installable */
 	if (!(opt & OPT_force_ignore_depends)) {
 		if (!check_deps(deb_file, 0 /*, deb_count*/)) {
-			bb_error_msg_and_die("dependency check failed");
+			bb_simple_error_msg_and_die("dependency check failed");
 		}
 	}
 

archival/gzip.c

@@ -99,7 +99,7 @@ aa:      85.1% -- replaced with aa.gz
 /* Diagnostic functions */
 #ifdef DEBUG
 static int verbose;
-#  define Assert(cond,msg) { if (!(cond)) bb_error_msg(msg); }
+#  define Assert(cond,msg) { if (!(cond)) bb_simple_error_msg(msg); }
 #  define Trace(x) fprintf x
 #  define Tracev(x) {if (verbose) fprintf x; }
 #  define Tracevv(x) {if (verbose > 1) fprintf x; }
@@ -787,7 +787,7 @@ static void check_match(IPos start, IPos match, int length)
 	/* check that the match is indeed a match */
 	if (memcmp(G1.window + match, G1.window + start, length) != 0) {
 		bb_error_msg(" start %d, match %d, length %d", start, match, length);
-		bb_error_msg("invalid match");
+		bb_simple_error_msg("invalid match");
 	}
 	if (verbose > 1) {
 		bb_error_msg("\\[%d,%d]", start - match, length);

archival/libarchive/data_extract_all.c

@@ -103,7 +103,7 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
 		struct stat existing_sb;
 		if (lstat(dst_name, &existing_sb) == -1) {
 			if (errno != ENOENT) {
-				bb_perror_msg_and_die("can't stat old file");
+				bb_simple_perror_msg_and_die("can't stat old file");
 			}
 		}
 		else if (existing_sb.st_mtime >= file_header->mtime) {
@@ -207,7 +207,7 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
 		}
 		break;
 	default:
-		bb_error_msg_and_die("unrecognized file type");
+		bb_simple_error_msg_and_die("unrecognized file type");
 	}
 
 	if (!S_ISLNK(file_header->mode)) {

archival/libarchive/decompress_bunzip2.c

@@ -817,7 +817,7 @@ unpack_bz2_stream(transformer_state_t *xstate)
 			break;
 		}
 		if (bd->headerCRC != bd->totalCRC) {
-			bb_error_msg("CRC error");
+			bb_simple_error_msg("CRC error");
 			break;
 		}
 

archival/libarchive/decompress_gunzip.c

@@ -1012,7 +1012,7 @@ inflate_unzip_internal(STATE_PARAM transformer_state_t *xstate)
 	error_msg = "corrupted data";
 	if (setjmp(error_jmp)) {
 		/* Error from deep inside zip machinery */
-		bb_error_msg(error_msg);
+		bb_simple_error_msg(error_msg);
 		n = -1;
 		goto ret;
 	}
@@ -1085,7 +1085,7 @@ static int top_up(STATE_PARAM unsigned n)
 		bytebuffer_offset = 0;
 		bytebuffer_size = full_read(gunzip_src_fd, &bytebuffer[count], bytebuffer_max - count);
 		if ((int)bytebuffer_size < 0) {
-			bb_error_msg(bb_msg_read_error);
+			bb_simple_error_msg(bb_msg_read_error);
 			return 0;
 		}
 		bytebuffer_size += count;
@@ -1211,7 +1211,7 @@ unpack_gz_stream(transformer_state_t *xstate)
 
 		if (full_read(xstate->src_fd, &magic2, 2) != 2) {
  bad_magic:
-			bb_error_msg("invalid magic");
+			bb_simple_error_msg("invalid magic");
 			return -1;
 		}
 		if (magic2 == COMPRESS_MAGIC) {
@@ -1233,7 +1233,7 @@ unpack_gz_stream(transformer_state_t *xstate)
 
  again:
 	if (!check_header_gzip(PASS_STATE xstate)) {
-		bb_error_msg("corrupted data");
+		bb_simple_error_msg("corrupted data");
 		total = -1;
 		goto ret;
 	}
@@ -1246,23 +1246,23 @@ unpack_gz_stream(transformer_state_t *xstate)
 	total += n;
 
 	if (!top_up(PASS_STATE 8)) {
-		bb_error_msg("corrupted data");
+		bb_simple_error_msg("corrupted data");
 		total = -1;
 		goto ret;
 	}
 
 	/* Validate decompression - crc */
 	v32 = buffer_read_le_u32(PASS_STATE_ONLY);
 	if ((~gunzip_crc) != v32) {
-		bb_error_msg("crc error");
+		bb_simple_error_msg("crc error");
 		total = -1;
 		goto ret;
 	}
 
 	/* Validate decompression - size */
 	v32 = buffer_read_le_u32(PASS_STATE_ONLY);
 	if ((uint32_t)gunzip_bytes_out != v32) {
-		bb_error_msg("incorrect length");
+		bb_simple_error_msg("incorrect length");
 		total = -1;
 	}
 

archival/libarchive/decompress_uncompress.c

@@ -113,7 +113,7 @@ unpack_Z_stream(transformer_state_t *xstate)
 	/* xread isn't good here, we have to return - caller may want
 	 * to do some cleanup (e.g. delete incomplete unpacked file etc) */
 	if (full_read(xstate->src_fd, inbuf, 1) != 1) {
-		bb_error_msg("short read");
+		bb_simple_error_msg("short read");
 		goto err;
 	}
 
@@ -166,7 +166,7 @@ unpack_Z_stream(transformer_state_t *xstate)
 		if (insize < (int) (IBUFSIZ + 64) - IBUFSIZ) {
 			rsize = safe_read(xstate->src_fd, inbuf + insize, IBUFSIZ);
 			if (rsize < 0)
-				bb_error_msg_and_die(bb_msg_read_error);
+				bb_simple_error_msg_and_die(bb_msg_read_error);
 			insize += rsize;
 		}
 
@@ -200,7 +200,7 @@ unpack_Z_stream(transformer_state_t *xstate)
 
 			if (oldcode == -1) {
 				if (code >= 256)
-					bb_error_msg_and_die("corrupted data"); /* %ld", code); */
+					bb_simple_error_msg_and_die("corrupted data"); /* %ld", code); */
 				oldcode = code;
 				finchar = (int) oldcode;
 				outbuf[outpos++] = (unsigned char) finchar;
@@ -236,7 +236,7 @@ unpack_Z_stream(transformer_state_t *xstate)
 						insize, posbits, p[-1], p[0], p[1], p[2], p[3],
 						(posbits & 07));
 */
-					bb_error_msg("corrupted data");
+					bb_simple_error_msg("corrupted data");
 					goto err;
 				}
 
@@ -247,7 +247,7 @@ unpack_Z_stream(transformer_state_t *xstate)
 			/* Generate output characters in reverse order */
 			while (code >= 256) {
 				if (stackp <= &htabof(0))
-					bb_error_msg_and_die("corrupted data");
+					bb_simple_error_msg_and_die("corrupted data");
 				*--stackp = tab_suffixof(code);
 				code = tab_prefixof(code);
 			}

archival/libarchive/decompress_unlzma.c

@@ -59,7 +59,7 @@ static void rc_read(rc_t *rc)
 //TODO: return -1 instead
 //This will make unlzma delete broken unpacked file on unpack errors
 	if (buffer_size <= 0)
-		bb_error_msg_and_die("unexpected EOF");
+		bb_simple_error_msg_and_die("unexpected EOF");
 	rc->buffer_end = RC_BUFFER + buffer_size;
 	rc->ptr = RC_BUFFER;
 }
@@ -234,7 +234,7 @@ unpack_lzma_stream(transformer_state_t *xstate)
 	if (full_read(xstate->src_fd, &header, sizeof(header)) != sizeof(header)
 	 || header.pos >= (9 * 5 * 5)
 	) {
-		bb_error_msg("bad lzma header");
+		bb_simple_error_msg("bad lzma header");
 		return -1;
 	}
 
@@ -513,7 +513,7 @@ unpack_lzma_stream(transformer_state_t *xstate)
 			 * potentially more detailed information).
 			 * Do not fail silently.
 			 */
-			bb_error_msg("corrupted data");
+			bb_simple_error_msg("corrupted data");
 			total_written = -1; /* failure */
 		}
 		rc_free(rc);

archival/libarchive/decompress_unxz.c

@@ -74,7 +74,7 @@ unpack_xz_stream(transformer_state_t *xstate)
 		if (iobuf.in_pos == iobuf.in_size) {
 			int rd = safe_read(xstate->src_fd, membuf, BUFSIZ);
 			if (rd < 0) {
-				bb_error_msg(bb_msg_read_error);
+				bb_simple_error_msg(bb_msg_read_error);
 				total = -1;
 				break;
 			}
@@ -123,7 +123,7 @@ unpack_xz_stream(transformer_state_t *xstate)
 			continue;
 		}
 		if (xz_result != XZ_OK && xz_result != XZ_UNSUPPORTED_CHECK) {
-			bb_error_msg("corrupted data");
+			bb_simple_error_msg("corrupted data");
 			total = -1;
 			break;
 		}

archival/libarchive/get_header_ar.c

@@ -22,7 +22,7 @@ static unsigned read_num(char *str, int base, int len)
 	 * on misformatted numbers bb_strtou returns all-ones */
 	err = bb_strtou(str, NULL, base);
 	if (err == -1)
-		bb_error_msg_and_die("invalid ar header");
+		bb_simple_error_msg_and_die("invalid ar header");
 	return err;
 }
 
@@ -53,7 +53,7 @@ char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
 	archive_handle->offset += 60;
 
 	if (ar.formatted.magic[0] != '`' || ar.formatted.magic[1] != '\n')
-		bb_error_msg_and_die("invalid ar header");
+		bb_simple_error_msg_and_die("invalid ar header");
 
 	/*
 	 * Note that the fields MUST be read in reverse order as
@@ -86,7 +86,7 @@ char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
 			return get_header_ar(archive_handle);
 		}
 #else
-		bb_error_msg_and_die("long filenames not supported");
+		bb_simple_error_msg_and_die("long filenames not supported");
 #endif
 	}
 	/* Only size is always present, the rest may be missing in
@@ -107,7 +107,7 @@ char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
 		long_offset = read_num(&ar.formatted.name[1], 10,
 				       sizeof(ar.formatted.name) - 1);
 		if (long_offset >= archive_handle->ar__long_name_size) {
-			bb_error_msg_and_die("can't resolve long filename");
+			bb_simple_error_msg_and_die("can't resolve long filename");
 		}
 		typed->name = xstrdup(archive_handle->ar__long_names + long_offset);
 	} else

archival/libarchive/get_header_cpio.c

@@ -33,14 +33,14 @@ char FAST_FUNC get_header_cpio(archive_handle_t *archive_handle)
 		goto create_hardlinks;
 	}
 	if (size != 110) {
-		bb_error_msg_and_die("short read");
+		bb_simple_error_msg_and_die("short read");
 	}
 	archive_handle->offset += 110;
 
 	if (!is_prefixed_with(&cpio_header[0], "07070")
 	 || (cpio_header[5] != '1' && cpio_header[5] != '2')
 	) {
-		bb_error_msg_and_die("unsupported cpio format, use newc or crc");
+		bb_simple_error_msg_and_die("unsupported cpio format, use newc or crc");
 	}
 
 	if (sscanf(cpio_header + 6,
@@ -50,7 +50,7 @@ char FAST_FUNC get_header_cpio(archive_handle_t *archive_handle)
 			&inode, &mode, &uid, &gid,
 			&nlink, &mtime, &size,
 			&major, &minor, &namesize) != 10)
-		bb_error_msg_and_die("damaged cpio file");
+		bb_simple_error_msg_and_die("damaged cpio file");
 	file_header->mode = mode;
 	/* "cpio -R USER:GRP" support: */
 	if (archive_handle->cpio__owner.uid != (uid_t)-1L)