Re: [patch 1/3] Make obconcat use stdarg

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> Date: Sun, 2 May 2010 09:52:17 +0200
> From: Jan Kratochvil <jan.kratochvil@redhat.com>
> 
> On Fri, 30 Apr 2010 21:08:48 +0200, Mark Kettenis wrote:
> > I'm afraid you'll need an explicit cast for the NULLs used as the
> > sentinel value
> 
> There is also needed a fix for cases already protected by ATTRIBUTE_SENTINEL
> and already using just the bare "NULL" sentinel:
> 
> concat reconcat concat_length concat_copy concat_copy2
> 
> fbsd-nat.c by Mark Kettenis 50e330a0 2004-09-19
> (reconcat has ATTRIBUTE_SENTINEL since bf7628f0 2004-09-05)
>         psargs = reconcat (psargs, psargs, " ", get_inferior_args (), NULL);
> remote.c [HAVE_LIBEXPAT]
>     remote_support_xml = concat ("xmlRegisters=", xml, NULL);
>       p = concat (remote_support_xml, ",", xml, NULL);
> remote.c d5ea7042 2010-03-30
>       char *p = concat (msg, ";", append, NULL);
>           char *p = concat ("qSupported:", q, NULL);
>       name = concat ("$", tsv->name, NULL);
> utils.c 8b58bcf2 2009-01-26
>                   concat ("maintenance set ", problem->name, " ", NULL),
>                   concat ("maintenance show ", problem->name, " ", NULL),
> 
> Nobody has noticed this problem since 2004.

Obviously the number of platforms that have:

1. Define NULL as an integer 0.

2. Use a compiler for which we turn on the sentinel warning.

is vanishingly small.

Incidentally I'm working on switching the OpenBSD system compiler from
GCC 3.x to GCC 4.x.  And warnings about the cases you mention above do
show up.  Here's a diff to address them.

ok?


2010-05-03  Mark Kettenis  <kettenis@faure.sibelius.xs4all.nl>

	* remote.c (register_remote_support_xml)
	(remote_query_supported_append, remote_query_supported): Add cast
	to NULL used as sentinel.
	* tracepoint.c (tvariables_info_1): Likewise.
	* utils.c (add_internal_problem_command): Likewise.


Index: remote.c
===================================================================
RCS file: /cvs/src/src/gdb/remote.c,v
retrieving revision 1.402
diff -u -p -r1.402 remote.c
--- remote.c	16 Apr 2010 07:49:35 -0000	1.402
+++ remote.c	3 May 2010 20:08:09 -0000
@@ -3473,7 +3473,7 @@ register_remote_support_xml (const char 
 {
 #if defined(HAVE_LIBEXPAT)
   if (remote_support_xml == NULL)
-    remote_support_xml = concat ("xmlRegisters=", xml, NULL);
+    remote_support_xml = concat ("xmlRegisters=", xml, (char *)NULL);
   else
     {
       char *copy = xstrdup (remote_support_xml + 13);
@@ -3491,7 +3491,7 @@ register_remote_support_xml (const char 
       while ((p = strtok (NULL, ",")) != NULL);
       xfree (copy);
 
-      p = concat (remote_support_xml, ",", xml, NULL);
+      p = concat (remote_support_xml, ",", xml, (char *)NULL);
       xfree (remote_support_xml);
       remote_support_xml = p;
     }
@@ -3503,7 +3503,7 @@ remote_query_supported_append (char *msg
 {
   if (msg)
     {
-      char *p = concat (msg, ";", append, NULL);
+      char *p = concat (msg, ";", append, (char *)NULL);
       xfree (msg);
       return p;
     }
@@ -3543,7 +3543,7 @@ remote_query_supported (void)
 
       if (q)
 	{
-	  char *p = concat ("qSupported:", q, NULL);
+	  char *p = concat ("qSupported:", q, (char *)NULL);
 	  xfree (q);
 	  putpkt (p);
 	  xfree (p);
Index: tracepoint.c
===================================================================
RCS file: /cvs/src/src/gdb/tracepoint.c,v
retrieving revision 1.184
diff -u -p -r1.184 tracepoint.c
--- tracepoint.c	23 Apr 2010 23:51:05 -0000	1.184
+++ tracepoint.c	3 May 2010 20:08:10 -0000
@@ -446,7 +446,7 @@ tvariables_info_1 (void)
 
       back_to2 = make_cleanup_ui_out_tuple_begin_end (uiout, "variable");
 
-      name = concat ("$", tsv->name, NULL);
+      name = concat ("$", tsv->name, (char *)NULL);
       make_cleanup (xfree, name);
       ui_out_field_string (uiout, "name", name);
       ui_out_field_string (uiout, "initial", plongest (tsv->initial_value));
Index: utils.c
===================================================================
RCS file: /cvs/src/src/gdb/utils.c,v
retrieving revision 1.228
diff -u -p -r1.228 utils.c
--- utils.c	8 Mar 2010 19:20:38 -0000	1.228
+++ utils.c	3 May 2010 20:08:11 -0000
@@ -1120,13 +1120,15 @@ add_internal_problem_command (struct int
   add_prefix_cmd ((char*) problem->name,
 		  class_maintenance, set_internal_problem_cmd, set_doc,
 		  set_cmd_list,
-		  concat ("maintenance set ", problem->name, " ", NULL),
+		  concat ("maintenance set ", problem->name, " ",
+			  (char *)NULL),
 		  0/*allow-unknown*/, &maintenance_set_cmdlist);
 
   add_prefix_cmd ((char*) problem->name,
 		  class_maintenance, show_internal_problem_cmd, show_doc,
 		  show_cmd_list,
-		  concat ("maintenance show ", problem->name, " ", NULL),
+		  concat ("maintenance show ", problem->name, " ",
+			  (char *)NULL),
 		  0/*allow-unknown*/, &maintenance_show_cmdlist);
 
   set_doc = xstrprintf (_("\