tar: code shrink, better help text

function                                             old     new   delta
tar_main                                             994    1013     +19
packed_usage                                       31893   31863     -30
writeTarFile                                         250     207     -43
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/2 up/down: 19/-73)            Total: -54 bytes

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

1 files changed, 68 insertions, 62 deletions

diff --git a/archival/tar.c b/archival/tar.c
index 08924903e..4f4a7d8f3 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -49,7 +49,7 @@
 //config:       tarballs. Currently it works only on files (not pipes etc).
 //config:
 //config:config FEATURE_TAR_FROM
-//config:       bool "Enable -X (exclude from) and -T (include from) options)"
+//config:       bool "Enable -X (exclude from) and -T (include from) options"
 //config:       default y
 //config:       depends on TAR
 //config:       help
@@ -156,7 +156,9 @@ typedef struct TarBallInfo {
         int tarFd;                      /* Open-for-write file descriptor
                                          * for the tarball */
         int verboseFlag;                /* Whether to print extra stuff or not */
+# if ENABLE_FEATURE_TAR_FROM
         const llist_t *excludeList;     /* List of files to not include */
+# endif
         HardLinkInfo *hlInfoHead;       /* Hard Link Tracking Information */
         HardLinkInfo *hlInfo;           /* Hard Link Info for the current file */
 //TODO: save only st_dev + st_ino
@@ -278,7 +280,7 @@ static void chksum_and_xwrite(int fd, struct tar_header_t* hp)
         xwrite(fd, hp, sizeof(*hp));
 }
 
-#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+# if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
 static void writeLongname(int fd, int type, const char *name, int dir)
 {
         static const struct {
@@ -318,7 +320,7 @@ static void writeLongname(int fd, int type, const char *name, int dir)
         memset(&header, 0, size);
         xwrite(fd, &header, size);
 }
-#endif
+# endif
 
 /* Write out a tar header for the specified file/directory/whatever */
 static int writeTarHeader(struct TarBallInfo *tbInfo,
@@ -347,30 +349,30 @@ static int writeTarHeader(struct TarBallInfo *tbInfo,
                 header.typeflag = LNKTYPE;
                 strncpy(header.linkname, tbInfo->hlInfo->name,
                                 sizeof(header.linkname));
-#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+# if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
                 /* Write out long linkname if needed */
                 if (header.linkname[sizeof(header.linkname)-1])
                         writeLongname(tbInfo->tarFd, GNULONGLINK,
                                         tbInfo->hlInfo->name, 0);
-#endif
+# endif
         } else if (S_ISLNK(statbuf->st_mode)) {
                 char *lpath = xmalloc_readlink_or_warn(fileName);
                 if (!lpath)
                         return FALSE;
                 header.typeflag = SYMTYPE;
                 strncpy(header.linkname, lpath, sizeof(header.linkname));
-#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+# if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
                 /* Write out long linkname if needed */
                 if (header.linkname[sizeof(header.linkname)-1])
                         writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
-#else
+# else
                 /* If it is larger than 100 bytes, bail out */
                 if (header.linkname[sizeof(header.linkname)-1]) {
                         free(lpath);
                         bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
                         return FALSE;
                 }
-#endif
+# endif
                 free(lpath);
         } else if (S_ISDIR(statbuf->st_mode)) {
                 header.typeflag = DIRTYPE;
@@ -400,9 +402,9 @@ static int writeTarHeader(struct TarBallInfo *tbInfo,
                  * It always does unless off_t is wider than 64 bits.
                  */
                 else if (ENABLE_FEATURE_TAR_GNU_EXTENSIONS
-#if ULLONG_MAX > 0xffffffffffffffffLL /* 2^64-1 */
+# if ULLONG_MAX > 0xffffffffffffffffLL /* 2^64-1 */
                  && (filesize <= 0x3fffffffffffffffffffffffLL)
-#endif
+# endif
                 ) {
                         /* GNU tar uses "base-256 encoding" for very large numbers.
                          * Encoding is binary, with highest bit always set as a marker
@@ -429,13 +431,13 @@ static int writeTarHeader(struct TarBallInfo *tbInfo,
                 return FALSE;
         }
 
-#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+# if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
         /* Write out long name if needed */
         /* (we, like GNU tar, output long linkname *before* long name) */
         if (header.name[sizeof(header.name)-1])
                 writeLongname(tbInfo->tarFd, GNULONGNAME,
                                 header_name, S_ISDIR(statbuf->st_mode));
-#endif
+# endif
 
         /* Now write the header out to disk */
         chksum_and_xwrite(tbInfo->tarFd, &header);
@@ -457,7 +459,7 @@ static int writeTarHeader(struct TarBallInfo *tbInfo,
         return TRUE;
 }
 
-#if ENABLE_FEATURE_TAR_FROM
+# if ENABLE_FEATURE_TAR_FROM
 static int exclude_file(const llist_t *excluded_files, const char *file)
 {
         while (excluded_files) {
@@ -483,9 +485,9 @@ static int exclude_file(const llist_t *excluded_files, const char *file)
 
         return 0;
 }
-#else
-# define exclude_file(excluded_files, file) 0
-#endif
+# else
+#  define exclude_file(excluded_files, file) 0
+# endif
 
 static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statbuf,
                         void *userData, int depth UNUSED_PARAM)
@@ -538,12 +540,12 @@ static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statb
         if (exclude_file(tbInfo->excludeList, header_name))
                 return SKIP;
 
-#if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+# if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
         if (strlen(header_name) >= NAME_SIZE) {
                 bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
                 return TRUE;
         }
-#endif
+# endif
 
         /* Is this a regular file? */
         if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
@@ -590,7 +592,7 @@ static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statb
         return TRUE;
 }
 
-#if SEAMLESS_COMPRESSION
+# if SEAMLESS_COMPRESSION
 /* Don't inline: vfork scares gcc and pessimizes code */
 static void NOINLINE vfork_compressor(int tar_fd, const char *gzip)
 {
@@ -598,13 +600,13 @@ static void NOINLINE vfork_compressor(int tar_fd, const char *gzip)
 
         // On Linux, vfork never unpauses parent early, although standard
         // allows for that. Do we want to waste bytes checking for it?
-# define WAIT_FOR_CHILD 0
+#  define WAIT_FOR_CHILD 0
         volatile int vfork_exec_errno = 0;
         struct fd_pair gzipDataPipe;
-# if WAIT_FOR_CHILD
+#  if WAIT_FOR_CHILD
         struct fd_pair gzipStatusPipe;
         xpiped_pair(gzipStatusPipe);
-# endif
+#  endif
         xpiped_pair(gzipDataPipe);
 
         signal(SIGPIPE, SIG_IGN); /* we only want EPIPE on errors */
@@ -615,12 +617,12 @@ static void NOINLINE vfork_compressor(int tar_fd, const char *gzip)
                 /* child */
                 /* NB: close _first_, then move fds! */
                 close(gzipDataPipe.wr);
-# if WAIT_FOR_CHILD
+#  if WAIT_FOR_CHILD
                 close(gzipStatusPipe.rd);
                 /* gzipStatusPipe.wr will close only on exec -
                  * parent waits for this close to happen */
                 fcntl(gzipStatusPipe.wr, F_SETFD, FD_CLOEXEC);
-# endif
+#  endif
                 xmove_fd(gzipDataPipe.rd, 0);
                 xmove_fd(tar_fd, 1);
                 /* exec gzip/bzip2 program/applet */
@@ -632,7 +634,7 @@ static void NOINLINE vfork_compressor(int tar_fd, const char *gzip)
         /* parent */
         xmove_fd(gzipDataPipe.wr, tar_fd);
         close(gzipDataPipe.rd);
-# if WAIT_FOR_CHILD
+#  if WAIT_FOR_CHILD
         close(gzipStatusPipe.wr);
         while (1) {
                 char buf;
@@ -644,55 +646,52 @@ static void NOINLINE vfork_compressor(int tar_fd, const char *gzip)
                         continue;       /* try it again */
         }
         close(gzipStatusPipe.rd);
-# endif
+#  endif
         if (vfork_exec_errno) {
                 errno = vfork_exec_errno;
                 bb_perror_msg_and_die("can't execute '%s'", gzip);
         }
 }
-#endif /* SEAMLESS_COMPRESSION */
+# endif /* SEAMLESS_COMPRESSION */
 
 
-#if !SEAMLESS_COMPRESSION
+# if !SEAMLESS_COMPRESSION
 /* Do not pass gzip flag to writeTarFile() */
-#define writeTarFile(tar_fd, verboseFlag, recurseFlags, include, exclude, gzip) \
-        writeTarFile(tar_fd, verboseFlag, recurseFlags, include, exclude)
-#endif
+#define writeTarFile(tbInfo, recurseFlags, filelist, gzip) \
+        writeTarFile(tbInfo, recurseFlags, filelist)
+# endif
 /* gcc 4.2.1 inlines it, making code bigger */
-static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
-        int recurseFlags, const llist_t *include,
-        const llist_t *exclude, const char *gzip)
+static NOINLINE int writeTarFile(
+        struct TarBallInfo *tbInfo,
+        int recurseFlags,
+        const llist_t *filelist,
+        const char *gzip)
 {
         int errorFlag = FALSE;
-        struct TarBallInfo tbInfo;
 
-        tbInfo.hlInfoHead = NULL;
-        tbInfo.tarFd = tar_fd;
-        tbInfo.verboseFlag = verboseFlag;
+        /*tbInfo->hlInfoHead = NULL; - already is */
 
         /* Store the stat info for the tarball's file, so
          * can avoid including the tarball into itself....  */
-        xfstat(tbInfo.tarFd, &tbInfo.tarFileStatBuf, "can't stat tar file");
+        xfstat(tbInfo->tarFd, &tbInfo->tarFileStatBuf, "can't stat tar file");
 
-#if SEAMLESS_COMPRESSION
+# if SEAMLESS_COMPRESSION
         if (gzip)
-                vfork_compressor(tbInfo.tarFd, gzip);
-#endif
-
-        tbInfo.excludeList = exclude;
+                vfork_compressor(tbInfo->tarFd, gzip);
+# endif
 
         /* Read the directory/files and iterate over them one at a time */
-        while (include) {
-                if (!recursive_action(include->data, recurseFlags,
-                                writeFileToTarball, writeFileToTarball, &tbInfo, 0)
+        while (filelist) {
+                if (!recursive_action(filelist->data, recurseFlags,
+                                writeFileToTarball, writeFileToTarball, tbInfo, 0)
                 ) {
                         errorFlag = TRUE;
                 }
-                include = include->link;
+                filelist = filelist->link;
         }
         /* Write two empty blocks to the end of the archive */
         memset(block_buf, 0, 2*TAR_BLOCK_SIZE);
-        xwrite(tbInfo.tarFd, block_buf, 2*TAR_BLOCK_SIZE);
+        xwrite(tbInfo->tarFd, block_buf, 2*TAR_BLOCK_SIZE);
 
         /* To be pedantically correct, we would check if the tarball
          * is smaller than 20 tar blocks, and pad it if it was smaller,
@@ -700,16 +699,16 @@ static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
          * so is considered a waste of space */
 
         /* Close so the child process (if any) will exit */
-        close(tbInfo.tarFd);
+        close(tbInfo->tarFd);
 
         /* Hang up the tools, close up shop, head home */
         if (ENABLE_FEATURE_CLEAN_UP)
-                freeHardLinkInfo(&tbInfo.hlInfoHead);
+                freeHardLinkInfo(&tbInfo->hlInfoHead);
 
         if (errorFlag)
                 bb_error_msg("error exit delayed from previous errors");
 
-#if SEAMLESS_COMPRESSION
+# if SEAMLESS_COMPRESSION
         if (gzip) {
                 int status;
                 if (safe_waitpid(-1, &status, 0) == -1)
@@ -718,21 +717,25 @@ static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
                         /* gzip was killed or has exited with nonzero! */
                         errorFlag = TRUE;
         }
-#endif
+# endif
         return errorFlag;
 }
+
 #else /* !FEATURE_TAR_CREATE */
+
 # define writeTarFile(...) 0
+
 #endif
 
 #if ENABLE_FEATURE_TAR_FROM
 static llist_t *append_file_list_to_list(llist_t *list)
 {
-        FILE *src_stream;
-        char *line;
         llist_t *newlist = NULL;
 
         while (list) {
+                FILE *src_stream;
+                char *line;
+
                 src_stream = xfopen_stdin(llist_pop(&list));
                 while ((line = xmalloc_fgetline(src_stream)) != NULL) {
                         /* kill trailing '/' unless the string is just "/" */
@@ -758,7 +761,7 @@ static llist_t *append_file_list_to_list(llist_t *list)
 //usage:        IF_FEATURE_TAR_NOPRESERVE_TIME("m")
 //usage:        "vO] "
 //usage:        "[-f TARFILE] [-C DIR] "
-//usage:        IF_FEATURE_TAR_FROM("[-T FILE] [-X FILE] "IF_FEATURE_TAR_LONG_OPTIONS("[--exclude PATTERN] "))
+//usage:        IF_FEATURE_TAR_FROM("[-T FILE] [-X FILE] "IF_FEATURE_TAR_LONG_OPTIONS("[--exclude PATTERN]... "))
 //usage:        "[FILE]..."
 //usage:#define tar_full_usage "\n\n"
 //usage:        IF_FEATURE_TAR_CREATE("Create, extract, ")
@@ -1170,13 +1173,10 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
         if (base_dir)
                 xchdir(base_dir);
 
-        //if (SEAMLESS_COMPRESSION)
-        //      /* We need to know whether child (gzip/bzip/etc) exits abnormally */
-        //      signal(SIGCHLD, check_errors_in_children);
-
 #if ENABLE_FEATURE_TAR_CREATE
         /* Create an archive */
         if (opt & OPT_CREATE) {
+                struct TarBallInfo *tbInfo;
 # if SEAMLESS_COMPRESSION
                 const char *zipMode = NULL;
                 if (opt & OPT_COMPRESS)
@@ -1190,12 +1190,18 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
                 if (opt & OPT_XZ)
                         zipMode = "xz";
 # endif
+                tbInfo = xzalloc(sizeof(*tbInfo));
+                tbInfo->tarFd = tar_handle->src_fd;
+                tbInfo->verboseFlag = verboseFlag;
+# if ENABLE_FEATURE_TAR_FROM
+                tbInfo->excludeList = tar_handle->reject;
+# endif
                 /* NB: writeTarFile() closes tar_handle->src_fd */
-                return writeTarFile(tar_handle->src_fd, verboseFlag,
+                return writeTarFile(tbInfo,
                                 (opt & OPT_DEREFERENCE ? ACTION_FOLLOWLINKS : 0)
                                 | (opt & OPT_NORECURSION ? 0 : ACTION_RECURSE),
                                 tar_handle->accept,
-                                tar_handle->reject, zipMode);
+                                zipMode);
         }
 #endif