Silence most -Wzero-as-null-pointer-constant diagnostics

Replace 0 by NULL and {0} by {}.

Omit a few cases that aren't so trivial to fix.

Link: <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117059>
Link: <https://software.codidact.com/posts/292718/292759#answer-292759>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

3 files changed, 40 insertions, 40 deletions

diff --git a/argp/argp-fmtstream.c b/argp/argp-fmtstream.c
index eb0a886..35b5b1d 100644
--- a/argp/argp-fmtstream.c
+++ b/argp/argp-fmtstream.c
@@ -74,7 +74,7 @@ __argp_make_fmtstream (FILE *stream,
       if (! fs->buf)
 	{
 	  free (fs);
-	  fs = 0;
+	  fs = NULL;
 	}
       else
 	{
diff --git a/argp/argp-help.c b/argp/argp-help.c
index cc43f37..5c41fdc 100644
--- a/argp/argp-help.c
+++ b/argp/argp-help.c
@@ -443,7 +443,7 @@ make_hol (const struct argp *argp, struct hol_cluster *cluster)
   assert (hol);
 
   hol->num_entries = 0;
-  hol->clusters = 0;
+  hol->clusters = NULL;
 
   if (opts)
     {
@@ -615,7 +615,7 @@ static char
 hol_entry_first_short (const struct hol_entry *entry)
 {
   return hol_entry_short_iterate (entry, until_short,
-				  entry->argp->argp_domain, 0);
+				  entry->argp->argp_domain, NULL);
 }
 
 /* Returns the first valid long option in ENTRY, or NULL if there is none.  */
@@ -627,7 +627,7 @@ hol_entry_first_long (const struct hol_entry *entry)
   for (opt = entry->opt, num = entry->num; num > 0; opt++, num--)
     if (opt->name && ovisible (opt))
       return opt->name;
-  return 0;
+  return NULL;
 }
 
 /* Returns the entry in HOL with the long option name NAME, or NULL if there is
@@ -652,7 +652,7 @@ hol_find_entry (struct hol *hol, const char *name)
       entry++;
     }
 
-  return 0;
+  return NULL;
 }
 
 /* If an entry with the long option NAME occurs in HOL, set it's special
@@ -926,7 +926,7 @@ hol_append (struct hol *hol, struct hol *more)
   while (*cl_end)
     cl_end = &(*cl_end)->next;
   *cl_end = more->clusters;
-  more->clusters = 0;
+  more->clusters = NULL;
 
   /* Merge entries.  */
   if (more->num_entries > 0)
@@ -1299,7 +1299,7 @@ hol_entry_help (struct hol_entry *entry, const struct argp_state *state,
     {
       const char *tstr = real->doc ? dgettext (state == NULL ? NULL
 					       : state->root_argp->argp_domain,
-					       real->doc) : 0;
+					       real->doc) : NULL;
       const char *fstr = filter_doc (tstr, real->key, entry->argp, state);
       if (fstr && *fstr)
 	{
@@ -1339,7 +1339,7 @@ hol_help (struct hol *hol, const struct argp_state *state,
 {
   unsigned num;
   struct hol_entry *entry;
-  struct hol_help_state hhstate = { 0, 0, 0 };
+  struct hol_help_state hhstate = { NULL, 0, 0 };
 
   for (entry = hol->entries, num = hol->num_entries; num > 0; entry++, num--)
     hol_entry_help (entry, state, stream, &hhstate);
@@ -1351,7 +1351,7 @@ hol_help (struct hol *hol, const struct argp_state *state,
 Mandatory or optional arguments to long options are also mandatory or \
 optional for any corresponding short options.");
       const char *fstr = filter_doc (tstr, ARGP_KEY_HELP_DUP_ARGS_NOTE,
-				     state ? state->root_argp : 0, state);
+				     state ? state->root_argp : NULL, state);
       if (fstr && *fstr)
 	{
 	  __argp_fmtstream_putc (stream, '\n');
@@ -1511,7 +1511,7 @@ argp_args_usage (const struct argp *argp, const struct argp_state *state,
   char *our_level = *levels;
   int multiple = 0;
   const struct argp_child *child = argp->children;
-  const char *tdoc = dgettext (argp->argp_domain, argp->args_doc), *nl = 0;
+  const char *tdoc = dgettext (argp->argp_domain, argp->args_doc), *nl = NULL;
   const char *fdoc = filter_doc (tdoc, ARGP_KEY_HELP_ARGS_DOC, argp, state);
 
   if (fdoc)
@@ -1573,7 +1573,7 @@ argp_doc (const struct argp *argp, const struct argp_state *state,
 {
   const char *text;
   const char *inp_text;
-  void *input = 0;
+  void *input = NULL;
   int anything = 0;
   size_t inp_text_limit = 0;
   const char *doc = dgettext (argp->argp_domain, argp->doc);
@@ -1582,11 +1582,11 @@ argp_doc (const struct argp *argp, const struct argp_state *state,
   if (doc)
     {
       char *vt = strchr (doc, '\v');
-      inp_text = post ? (vt ? vt + 1 : 0) : doc;
+      inp_text = post ? (vt ? vt + 1 : NULL) : doc;
       inp_text_limit = (!post && vt) ? (vt - doc) : 0;
     }
   else
-    inp_text = 0;
+    inp_text = NULL;
 
   if (argp->help_filter)
     /* We have to filter the doc strings.  */
@@ -1628,7 +1628,7 @@ argp_doc (const struct argp *argp, const struct argp_state *state,
   if (post && argp->help_filter)
     /* Now see if we have to output a ARGP_KEY_HELP_EXTRA text.  */
     {
-      text = (*argp->help_filter) (ARGP_KEY_HELP_EXTRA, 0, input);
+      text = (*argp->help_filter) (ARGP_KEY_HELP_EXTRA, NULL, input);
       if (text)
 	{
 	  if (anything || pre_blank)
@@ -1661,7 +1661,7 @@ _help (const struct argp *argp, const struct argp_state *state, FILE *stream,
        unsigned flags, char *name)
 {
   int anything = 0;		/* Whether we've output anything.  */
-  struct hol *hol = 0;
+  struct hol *hol = NULL;
   argp_fmtstream_t fs;
 
   if (! stream)
@@ -1684,7 +1684,7 @@ _help (const struct argp *argp, const struct argp_state *state, FILE *stream,
 
   if (flags & (ARGP_HELP_USAGE | ARGP_HELP_SHORT_USAGE | ARGP_HELP_LONG))
     {
-      hol = argp_hol (argp, 0);
+      hol = argp_hol (argp, NULL);
 
       /* If present, these options always come last.  */
       hol_set_group (hol, "help", -1);
@@ -1801,7 +1801,7 @@ Try `%s --help' or `%s --usage' for more information.\n"),
 void __argp_help (const struct argp *argp, FILE *stream,
 		  unsigned flags, char *name)
 {
-  _help (argp, 0, stream, flags, name);
+  _help (argp, NULL, stream, flags, name);
 }
 #ifdef weak_alias
 weak_alias (__argp_help, argp_help)
@@ -1843,7 +1843,7 @@ __argp_state_help (const struct argp_state *state, FILE *stream, unsigned flags)
       if (state && (state->flags & ARGP_LONG_ONLY))
 	flags |= ARGP_HELP_LONG_ONLY;
 
-      _help (state ? state->root_argp : 0, state, stream, flags,
+      _help (state ? state->root_argp : NULL, state, stream, flags,
 	     state ? state->name : __argp_short_program_name ());
 
       if (!state || ! (state->flags & ARGP_NO_EXIT))
diff --git a/argp/argp-parse.c b/argp/argp-parse.c
index 9b7b91f..7a75fa3 100644
--- a/argp/argp-parse.c
+++ b/argp/argp-parse.c
@@ -83,13 +83,13 @@ static volatile int _argp_hang;
 
 static const struct argp_option argp_default_options[] =
 {
-  {"help",	  '?',	  	0, 0,  N_("Give this help list"), -1},
-  {"usage",	  OPT_USAGE,	0, 0,  N_("Give a short usage message")},
+  {"help",	  '?',	  	NULL, 0,  N_("Give this help list"), -1},
+  {"usage",	  OPT_USAGE,	NULL, 0,  N_("Give a short usage message")},
   {"program-name",OPT_PROGNAME, N_("NAME"), OPTION_HIDDEN,
    N_("Set the program name")},
   {"HANG",	  OPT_HANG,    N_("SECS"), OPTION_ARG_OPTIONAL | OPTION_HIDDEN,
    N_("Hang for SECS seconds (default 3600)")},
-  {0, 0}
+  {NULL, 0}
 };
 
 static error_t
@@ -149,8 +149,8 @@ static const struct argp argp_default_argp =
 
 static const struct argp_option argp_version_options[] =
 {
-  {"version",	  'V',	  	0, 0,  N_("Print program version"), -1},
-  {0, 0}
+  {"version",	  'V',	  	NULL, 0,  N_("Print program version"), -1},
+  {NULL, 0}
 };
 
 static error_t
@@ -341,7 +341,7 @@ convert_options (const struct argp *argp,
 			  ? optional_argument
 			  : required_argument)
 		       : no_argument);
-		    cvt->long_end->flag = 0;
+		    cvt->long_end->flag = NULL;
 		    /* we add a disambiguating code to all the user's
 		       values (which is removed before we actually call
 		       the function to parse the value); this means that
@@ -364,9 +364,9 @@ convert_options (const struct argp *argp,
       group->args_processed = 0;
       group->parent = parent;
       group->parent_index = parent_index;
-      group->input = 0;
-      group->hook = 0;
-      group->child_inputs = 0;
+      group->input = NULL;
+      group->hook = NULL;
+      group->child_inputs = NULL;
 
       if (children)
 	/* Assign GROUP's CHILD_INPUTS field some space from
@@ -382,7 +382,7 @@ convert_options (const struct argp *argp,
       parent = group++;
     }
   else
-    parent = 0;
+    parent = NULL;
 
   if (children)
     {
@@ -417,7 +417,7 @@ parser_convert (struct parser *parser, const struct argp *argp, int flags)
   parser->argp = argp;
 
   if (argp)
-    parser->egroup = convert_options (argp, 0, 0, parser->groups, &cvt);
+    parser->egroup = convert_options (argp, NULL, 0, parser->groups, &cvt);
   else
     parser->egroup = parser->groups; /* No parsers at all! */
 }
@@ -530,7 +530,7 @@ parser_init (struct parser *parser, const struct argp *argp,
 	   makes very simple wrapper argps more convenient).  */
 	group->child_inputs[0] = group->input;
 
-      err = group_parse (group, &parser->state, ARGP_KEY_INIT, 0);
+      err = group_parse (group, &parser->state, ARGP_KEY_INIT, NULL);
     }
   if (err == EBADKEY)
     err = 0;			/* Some parser didn't understand.  */
@@ -582,11 +582,11 @@ parser_finalize (struct parser *parser,
 	       group < parser->egroup && (!err || err==EBADKEY);
 	       group++)
 	    if (group->args_processed == 0)
-	      err = group_parse (group, &parser->state, ARGP_KEY_NO_ARGS, 0);
+	      err = group_parse (group, &parser->state, ARGP_KEY_NO_ARGS, NULL);
 	  for (group = parser->egroup - 1;
 	       group >= parser->groups && (!err || err==EBADKEY);
 	       group--)
-	    err = group_parse (group, &parser->state, ARGP_KEY_END, 0);
+	    err = group_parse (group, &parser->state, ARGP_KEY_END, NULL);
 
 	  if (err == EBADKEY)
 	    err = 0;		/* Some parser didn't understand.  */
@@ -625,7 +625,7 @@ parser_finalize (struct parser *parser,
 
       /* Since we didn't exit, give each parser an error indication.  */
       for (group = parser->groups; group < parser->egroup; group++)
-	group_parse (group, &parser->state, ARGP_KEY_ERROR, 0);
+	group_parse (group, &parser->state, ARGP_KEY_ERROR, NULL);
     }
   else
     /* Notify parsers of success, and propagate back values from parsers.  */
@@ -636,14 +636,14 @@ parser_finalize (struct parser *parser,
       for (group = parser->egroup - 1
 	   ; group >= parser->groups && (!err || err == EBADKEY)
 	   ; group--)
-	err = group_parse (group, &parser->state, ARGP_KEY_SUCCESS, 0);
+	err = group_parse (group, &parser->state, ARGP_KEY_SUCCESS, NULL);
       if (err == EBADKEY)
 	err = 0;		/* Some parser didn't understand.  */
     }
 
   /* Call parsers once more, to do any final cleanup.  Errors are ignored.  */
   for (group = parser->egroup - 1; group >= parser->groups; group--)
-    group_parse (group, &parser->state, ARGP_KEY_FINI, 0);
+    group_parse (group, &parser->state, ARGP_KEY_FINI, NULL);
 
   if (err == EBADKEY)
     err = EINVAL;
@@ -682,7 +682,7 @@ parser_parse_arg (struct parser *parser, char *val)
 	{
 	  parser->state.next--;	/* For ARGP_KEY_ARGS, put back the arg.  */
 	  key = ARGP_KEY_ARGS;
-	  err = group_parse (group, &parser->state, key, 0);
+	  err = group_parse (group, &parser->state, key, NULL);
 	}
     }
 
@@ -792,11 +792,11 @@ parser_parse_next (struct parser *parser, int *arg_ebadkey)
       parser->opt_data.optopt = KEY_END;
       if (parser->state.flags & ARGP_LONG_ONLY)
 	opt = _getopt_long_only_r (parser->state.argc, parser->state.argv,
-				   parser->short_opts, parser->long_opts, 0,
+				   parser->short_opts, parser->long_opts, NULL,
 				   &parser->opt_data);
       else
 	opt = _getopt_long_r (parser->state.argc, parser->state.argv,
-			      parser->short_opts, parser->long_opts, 0,
+			      parser->short_opts, parser->long_opts, NULL,
 			      &parser->opt_data);
       /* And see what getopt did.  */
       parser->state.next = parser->opt_data.optind;
@@ -893,7 +893,7 @@ __argp_parse (const struct argp *argp, int argc, char **argv, unsigned flags,
       child[child_index++].argp = &argp_default_argp;
       if (argp_program_version || argp_program_version_hook)
 	child[child_index++].argp = &argp_version_argp;
-      child[child_index].argp = 0;
+      child[child_index].argp = NULL;
 
       argp = &top_argp;
     }
@@ -930,7 +930,7 @@ __argp_input (const struct argp *argp, const struct argp_state *state)
 	  return group->input;
     }
 
-  return 0;
+  return NULL;
 }
 #ifdef weak_alias
 weak_alias (__argp_input, _argp_input)