*: better string sharing

text   data    bss    dec    hex filename
 849427    441   7556 857424  d1550 busybox_old
 849355    441   7556 857352  d1508 busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

archival/bzip2.c

@@ -88,7 +88,7 @@ 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" : "write error");
+				bb_perror_msg(n2 >= 0 ? "short write" : bb_msg_write_error);
 				return -1;
 			}
 		}
@@ -118,7 +118,7 @@ IF_DESKTOP(long long) int FAST_FUNC compressStream(unpack_info_t *info UNUSED_PA
 	while (1) {
 		count = full_read(STDIN_FILENO, rbuf, IOBUF_SIZE);
 		if (count < 0) {
-			bb_perror_msg("read error");
+			bb_perror_msg(bb_msg_read_error);
 			total = -1;
 			break;
 		}

archival/libunarchive/decompress_unxz.c

@@ -86,7 +86,7 @@ unpack_xz_stream(int src_fd, int dst_fd)
 		if (rd) {
 			rd = safe_read(src_fd, membuf + insz, rd);
 			if (rd < 0) {
-				bb_error_msg("read error");
+				bb_error_msg(bb_msg_read_error);
 				total = -1;
 				break;
 			}

archival/libunarchive/decompress_unzip.c

@@ -1072,7 +1072,7 @@ 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("read error");
+			bb_error_msg(bb_msg_read_error);
 			return 0;
 		}
 		bytebuffer_size += count;

coreutils/head.c

@@ -27,7 +27,7 @@ static const struct suffix_mult head_suffixes[] = {
 	{ "", 0 }
 };
 
-static const char header_fmt_str[] ALIGN1 = "\n==> %s <==\n";
+#define header_fmt_str "\n==> %s <==\n"
 
 int head_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int head_main(int argc, char **argv)

coreutils/od_bloaty.c

@@ -502,7 +502,7 @@ check_and_close(void)
 	}
 
 	if (ferror(stdout)) {
-		bb_error_msg("write error");
+		bb_error_msg(bb_msg_write_error);
 		ioerror = 1;
 	}
 }

coreutils/tail.c

@@ -66,7 +66,7 @@ static ssize_t tail_read(int fd, char *buf, size_t count)
 	return r;
 }
 
-static const char header_fmt[] ALIGN1 = "\n==> %s <==\n";
+#define header_fmt_str "\n==> %s <==\n"
 
 static unsigned eat_num(const char *p)
 {
@@ -166,7 +166,7 @@ int tail_main(int argc, char **argv)
 	tailbuf = xmalloc(tailbufsize);
 
 	/* tail the files */
-	fmt = header_fmt + 1; /* skip header leading newline on first output */
+	fmt = header_fmt_str + 1; /* skip header leading newline on first output */
 	i = 0;
 	do {
 		char *buf;
@@ -181,7 +181,7 @@ int tail_main(int argc, char **argv)
 
 		if (nfiles > header_threshhold) {
 			tail_xprint_header(fmt, argv[i]);
-			fmt = header_fmt;
+			fmt = header_fmt_str;
 		}
 
 		if (!from_top) {
@@ -333,7 +333,7 @@ int tail_main(int argc, char **argv)
 			if (ENABLE_FEATURE_FANCY_TAIL && fd < 0)
 				continue;
 			if (nfiles > header_threshhold) {
-				fmt = header_fmt;
+				fmt = header_fmt_str;
 			}
 			while ((nread = tail_read(fd, tailbuf, BUFSIZ)) > 0) {
 				if (fmt) {

miscutils/less.c

@@ -430,7 +430,7 @@ static void read_lines(void)
 					 * immediately */
 					eof_error = 1;
 				} else {
-					print_statusline("read error");
+					print_statusline(bb_msg_read_error);
 				}
 			}
 #if !ENABLE_FEATURE_LESS_REGEXP

modutils/modutils-24.c

@@ -3529,20 +3529,18 @@ static void set_tainted(int fd, const char *m_name,
 /* Check if loading this module will taint the kernel. */
 static void check_tainted_module(struct obj_file *f, const char *m_name)
 {
-	static const char tainted_file[] ALIGN1 = TAINT_FILENAME;
-
 	int fd, kernel_has_tainted;
 	const char *ptr;
 
 	kernel_has_tainted = 1;
-	fd = open(tainted_file, O_RDWR);
+	fd = open(TAINT_FILENAME, O_RDWR);
 	if (fd < 0) {
 		if (errno == ENOENT)
 			kernel_has_tainted = 0;
 		else if (errno == EACCES)
 			kernel_has_tainted = 1;
 		else {
-			perror(tainted_file);
+			perror(TAINT_FILENAME);
 			kernel_has_tainted = 0;
 		}
 	}

shell/ash.c

@@ -119,9 +119,7 @@ enum { NOPTS = ARRAY_SIZE(optletters_optnames) };
 
 /* ============ Misc data */
 
-static const char homestr[] ALIGN1 = "HOME";
+#define msg_illnum "Illegal number: %s"
-static const char snlfmt[] ALIGN1 = "%s\n";
-static const char msg_illnum[] ALIGN1 = "Illegal number: %s";
 
 /*
  * We enclose jmp_buf in a structure so that we can declare pointers to
@@ -2520,7 +2518,7 @@ cdcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 	flags = cdopt();
 	dest = *argptr;
 	if (!dest)
-		dest = bltinlookup(homestr);
+		dest = bltinlookup("HOME");
 	else if (LONE_DASH(dest)) {
 		dest = bltinlookup("OLDPWD");
 		flags |= CD_PRINT;
@@ -2567,7 +2565,7 @@ cdcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 	/* NOTREACHED */
  out:
 	if (flags & CD_PRINT)
-		out1fmt(snlfmt, curdir);
+		out1fmt("%s\n", curdir);
 	return 0;
 }
 
@@ -2583,7 +2581,7 @@ pwdcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 			setpwd(dir, 0);
 		dir = physdir;
 	}
-	out1fmt(snlfmt, dir);
+	out1fmt("%s\n", dir);
 	return 0;
 }
 
@@ -5625,7 +5623,7 @@ exptilde(char *startp, char *p, int flags)
  done:
 	*p = '\0';
 	if (*name == '\0') {
-		home = lookupvar(homestr);
+		home = lookupvar("HOME");
 	} else {
 		pw = getpwnam(name);
 		if (pw == NULL)
@@ -9857,7 +9855,7 @@ chkmail(void)
 		}
 		if (!mail_var_path_changed && statb.st_mtime != *mtp) {
 			fprintf(
-				stderr, snlfmt,
+				stderr, "%s\n",
 				pathopt ? pathopt : "you have mail"
 			);
 		}

util-linux/fdisk.c

@@ -107,9 +107,9 @@ struct partition {
 	unsigned char size4[4];         /* nr of sectors in partition */
 } PACKED;
 
-static const char unable_to_open[] ALIGN1 = "can't open '%s'";
+#define unable_to_open "can't open '%s'"
-static const char unable_to_read[] ALIGN1 = "can't read from %s";
+#define unable_to_read "can't read from %s"
-static const char unable_to_seek[] ALIGN1 = "can't seek on %s";
+#define unable_to_seek "can't seek on %s"
 
 enum label_type {
 	LABEL_DOS, LABEL_SUN, LABEL_SGI, LABEL_AIX, LABEL_OSF