Fix problems caught by static checking

Most of these can be caught by configuring with --enable-gcc-warnings.
Problem reported by Pavel Raiskup in:
http://lists.gnu.org/archive/html/bug-tar/2015-09/msg00001.html
* src/buffer.c (format_total_stats):
Prefer pointer to const when it’s OK to use const.
(default_total_format): Now const.
* src/buffer.c (default_total_format):
* src/exclist.c (excfile_head, excfile_tail, vcs_ignore_files):
* src/misc.c (namebuf_add_dir, namebuf_finish):
* src/tar.c (verbatim_files_from_option, option_set_in_cl)
(optloc_eq, set_old_files_option):
Now static.
* src/common.h: Adjust to match the other changes described here.
* src/exclist.c (info_cleanup_exclist):
* src/tar.c (argp_program_version, argp_program_bug_address):
Remove; unused.
(parse_default_options): Define via prototype instead of old style.
(parse_default_options, decode_options):
Fill out incomplete initializers.

src/buffer.c

@@ -517,7 +517,7 @@ print_stats (FILE *fp, const char *text, tarlong numbytes)
    from the archive), EOL is a delimiter to add at the end of the output
    line. */
 int
-format_total_stats (FILE *fp, const char **formats, int eor, int eol)
+format_total_stats (FILE *fp, char const *const *formats, int eor, int eol)
 {
   int n;
 
@@ -573,7 +573,7 @@ format_total_stats (FILE *fp, const char **formats, int eor, int eol)
   return n;
 }
 
-const char *default_total_format[] = {
+static char const *const default_total_format[] = {
   N_("Total bytes read"),
   /* Amanda 2.4.1p1 looks for "Total bytes written: [0-9][0-9]*".  */
   N_("Total bytes written"),

src/common.h

@@ -386,9 +386,6 @@ GLOBAL dev_t root_device;
 /* Unquote filenames */
 GLOBAL bool unquote_option;
 
-/* Treat file names read from -T input verbatim */
-GLOBAL bool verbatim_files_from_option;
-
 GLOBAL int savedir_sort_order;
 
 /* Show file or archive names after transformation.
@@ -456,7 +453,7 @@ void set_start_time (void);
 #define TF_READ    0
 #define TF_WRITE   1
 #define TF_DELETED 2
-int format_total_stats (FILE *fp, const char **formats, int eor, int eol);
+int format_total_stats (FILE *fp, char const *const *formats, int eor, int eol);
 void print_total_stats (void);
 
 void mv_begin_write (const char *file_name, off_t totsize, off_t sizeleft);
@@ -623,8 +620,6 @@ typedef struct namebuf *namebuf_t;
 namebuf_t namebuf_create (const char *dir);
 void namebuf_free (namebuf_t buf);
 char *namebuf_name (namebuf_t buf, const char *name);
-void namebuf_add_dir (namebuf_t buf, const char *name);
-char *namebuf_finish (namebuf_t buf);
 
 const char *tar_dirname (void);
 
@@ -953,7 +948,6 @@ extern void (*fatal_exit_hook) (void);
 
 void excfile_add (const char *name, int flags);
 void info_attach_exclist (struct tar_stat_info *dir);
-void info_cleanup_exclist (struct tar_stat_info *dir);
 void info_free_exclist (struct tar_stat_info *dir);
 bool excluded_name (char const *name, struct tar_stat_info *st);
 void exclude_vcs_ignores (void);

src/exclist.c

@@ -43,7 +43,7 @@ struct excfile
   char name[1];
 };
 
-struct excfile *excfile_head, *excfile_tail;
+static struct excfile *excfile_head, *excfile_tail;
 
 void
 excfile_add (const char *name, int flags)
@@ -129,34 +129,6 @@ info_attach_exclist (struct tar_stat_info *dir)
   dir->exclude_list = head;
 }
 
-void
-info_cleanup_exclist (struct tar_stat_info *dir)
-{
-  struct exclist *ep = dir->exclude_list;
-
-  while (ep)
-    {
-      struct exclist *next = ep->next;
-      
-      if (ep->flags & EXCL_NON_RECURSIVE)
-	{
-	  
-	  /* Remove the entry */
-	  if (ep->prev)
-	    ep->prev->next = ep->next;
-	  else
-	    dir->exclude_list = ep->next;
-
-	  if (ep->next)
-	    ep->next->prev = ep->prev;
-
-	  free_exclude (ep->excluded);
-	  free (ep);
-	}
-      ep = next;
-    }
-}
-
 void
 info_free_exclist (struct tar_stat_info *dir)
 {
@@ -331,7 +303,7 @@ hg_addfn (struct exclude *ex, char const *pattern, int options, void *data)
 		: (options & ~EXCLUDE_REGEX)) | *hgopt);
 }
 
-struct vcs_ignore_file vcs_ignore_files[] = {
+static struct vcs_ignore_file vcs_ignore_files[] = {
   { ".cvsignore", EXCL_NON_RECURSIVE, cvs_addfn, NULL, NULL },
   { ".gitignore", 0, git_addfn, NULL, NULL },
   { ".bzrignore", 0, bzr_addfn, NULL, NULL },

src/misc.c

@@ -29,6 +29,8 @@
 # define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
 #endif
 
+static void namebuf_add_dir (namebuf_t, char const *);
+static char *namebuf_finish (namebuf_t);
 static const char *tar_getcdpath (int);
 
 
@@ -1202,7 +1204,7 @@ namebuf_name (namebuf_t buf, const char *name)
   return buf->buffer;
 }
 
-void
+static void
 namebuf_add_dir (namebuf_t buf, const char *name)
 {
   static char dirsep[] = { DIRECTORY_SEPARATOR, 0 };
@@ -1215,7 +1217,7 @@ namebuf_add_dir (namebuf_t buf, const char *name)
   buf->dir_length += strlen (name);
 }
 
-char *
+static char *
 namebuf_finish (namebuf_t buf)
 {
   char *res = buf->buffer;

src/tar.c

@@ -74,6 +74,9 @@ static int check_links_option;
 /* Number of allocated tape drive names.  */
 static size_t allocated_archive_names;
 
+/* Treat file names read from -T input verbatim */
+static bool verbatim_files_from_option;
+
 
 /* Miscellaneous.  */
 
@@ -376,8 +379,6 @@ enum
   XATTR_INCLUDE
 };
 
-const char *argp_program_version = "tar (" PACKAGE_NAME ") " VERSION;
-const char *argp_program_bug_address = "<" PACKAGE_BUGREPORT ">";
 static char const doc[] = N_("\
 GNU 'tar' saves many files together into a single tape or disk archive, \
 and can restore individual files from the archive.\n\
@@ -1080,7 +1081,7 @@ optloc_lookup (int id)
 }
 
 /* Return true if the latest occurrence of option ID was in the command line */
-int
+static int
 option_set_in_cl (int id)
 {
   struct option_locus *loc = optloc_lookup (id);
@@ -1090,7 +1091,7 @@ option_set_in_cl (int id)
 }
 
 /* Compare two option locations */
-int
+static int
 optloc_eq (struct option_locus *a, struct option_locus *b)
 {
   if (a->source != b->source)
@@ -1458,11 +1459,11 @@ static int sort_mode_flag[] = {
 
 ARGMATCH_VERIFY (sort_mode_arg, sort_mode_flag);
 
-void
+static void
 set_old_files_option (int code, struct option_locus *loc)
 {
   struct option_locus *prev;
-  static char *code_to_opt[] = {
+  static char const *const code_to_opt[] = {
     "--overwrite-dir",
     "--no-overwrite-dir",
     "--overwrite",
@@ -2460,12 +2461,12 @@ more_options (int argc, char **argv, struct option_locus *loc)
     USAGE_ERROR ((0, 0, _("non-option arguments in %s"), loc->name));
 }
 
-void
-parse_default_options ()
+static void
+parse_default_options (void)
 {
   char *opts = getenv ("TAR_OPTIONS");
   struct wordsplit ws;
-  struct option_locus loc = { OPTS_ENVIRON, "TAR_OPTIONS", 0 };
+  struct option_locus loc = { OPTS_ENVIRON, "TAR_OPTIONS", 0, 0 };
 
   if (!opts)
     return;
@@ -2487,7 +2488,7 @@ static void
 decode_options (int argc, char **argv)
 {
   int idx;
-  struct option_locus loc = { OPTS_COMMAND_LINE };
+  struct option_locus loc = { OPTS_COMMAND_LINE, 0, 0, 0 };
 
   argp_version_setup ("tar", tar_authors);