Vorbis dev - Aug 2007 - [Patch] Const correct tags functions

Hi all,

I tend to compile my code with all GCC warnings turned on. However,
when I do this :

   
vorbis_comment_add_tag(&vdata->vc,"ENCODER","libsndfile");

I get the following warning messages:

    warning: passing argument 2 of 'vorbis_comment_add_tag' discards 
        qualifiers from pointer target type
    warning: passing argument 3 of 'vorbis_comment_add_tag' discards 
        qualifiers from pointer target type

The problem is that string literals like "ENCODER" are be const
char * which vorbis_comment_add_tag is prototyped as having char *
pointers, even though the strings pointed to are not modified.

The following patch (against SVN head) makes the libvorbis const
correct.

Cheers,
Erik

---------------8<---------------8<---------------8<---------------
--- include/vorbis/codec.h	(revision 13502)
+++ include/vorbis/codec.h	(working copy)
@@ -166,11 +166,11 @@
 extern void     vorbis_info_clear(vorbis_info *vi);
 extern int      vorbis_info_blocksize(vorbis_info *vi,int zo);
 extern void     vorbis_comment_init(vorbis_comment *vc);
-extern void     vorbis_comment_add(vorbis_comment *vc, char *comment);
+extern void     vorbis_comment_add(vorbis_comment *vc, const char *comment);
 extern void     vorbis_comment_add_tag(vorbis_comment *vc,
-				       char *tag, char *contents);
-extern char    *vorbis_comment_query(vorbis_comment *vc, char *tag, int count);
-extern int      vorbis_comment_query_count(vorbis_comment *vc, char *tag);
+				       const char *tag, const char *contents);
+extern char    *vorbis_comment_query(vorbis_comment *vc, const char *tag, int
count);
+extern int      vorbis_comment_query_count(vorbis_comment *vc, const char
*tag);
 extern void     vorbis_comment_clear(vorbis_comment *vc);
 
 extern int      vorbis_block_init(vorbis_dsp_state *v, vorbis_block *vb);
--- lib/info.c	(revision 13502)
+++ lib/info.c	(working copy)
@@ -59,7 +59,7 @@
   memset(vc,0,sizeof(*vc));
 }
 
-void vorbis_comment_add(vorbis_comment *vc,char *comment){
+void vorbis_comment_add(vorbis_comment *vc,const char *comment){
   vc->user_comments=_ogg_realloc(vc->user_comments,
 			    (vc->comments+2)*sizeof(*vc->user_comments));
   vc->comment_lengths=_ogg_realloc(vc->comment_lengths,
@@ -71,7 +71,7 @@
   vc->user_comments[vc->comments]=NULL;
 }
 
-void vorbis_comment_add_tag(vorbis_comment *vc, char *tag, char *contents){
+void vorbis_comment_add_tag(vorbis_comment *vc, const char *tag, const char
*contents){
   char *comment=alloca(strlen(tag)+strlen(contents)+2); /* +2 for = and \0 */
   strcpy(comment, tag);
   strcat(comment, "=");
@@ -91,7 +91,7 @@
   return 0;
 }
 
-char *vorbis_comment_query(vorbis_comment *vc, char *tag, int count){
+char *vorbis_comment_query(vorbis_comment *vc, const char *tag, int count){
   long i;
   int found = 0;
   int taglen = strlen(tag)+1; /* +1 for the = we append */
@@ -112,7 +112,7 @@
   return NULL; /* didn't find anything */
 }
 
-int vorbis_comment_query_count(vorbis_comment *vc, char *tag){
+int vorbis_comment_query_count(vorbis_comment *vc, const char *tag){
   int i,count=0;
   int taglen = strlen(tag)+1; /* +1 for the = we append */
   char *fulltag = alloca(taglen+1);
---------------8<---------------8<---------------8<---------------


-- 
-----------------------------------------------------------------
Erik de Castro Lopo
-----------------------------------------------------------------
Journalist: Microsoft CEO Steve Ballmer has finally said Linux
            is the No. 1 threat to Windows. What's your response to that?
Linus     : "Tag, you're it." I don't care. They've had a
lot of
            enemies in their time. Let them fight one enemy that
            doesn't care for a change.

Erik de Castro Lopo wrote:
> The problem is that string literals like "ENCODER" are be const
> char * which vorbis_comment_add_tag is prototyped as having char *
> pointers, even though the strings pointed to are not modified.
> 
> The following patch (against SVN head) makes the libvorbis const
> correct.
Is someone able to take a look at this patch?

Erik
-- 
-----------------------------------------------------------------
Erik de Castro Lopo
-----------------------------------------------------------------
"Microsoft, and other companies with shoddy security, ....."
 -- Bruce Schneier, cryto-guru, to a US Senate committee.

On 14/08/07, Erik de Castro Lopo <mle+la@mega-nerd.com>
wrote:
> Erik de Castro Lopo wrote:
>
> > The problem is that string literals like "ENCODER" are be
const
> > char * which vorbis_comment_add_tag is prototyped as having char *
> > pointers, even though the strings pointed to are not modified.
> >
> > The following patch (against SVN head) makes the libvorbis const
> > correct.
>
> Is someone able to take a look at this patch?
The maintainer of libvorbis is Monty. Ping him on IRC, point to the
trac bug which includes this patch, wait.

cheers,

kfish.

Erik de Castro Lopo wrote:
> Is someone able to take a look at this patch?
If it helps, this is now in trac:

    https://trac.xiph.org/ticket/1228

Erik
-- 
-----------------------------------------------------------------
Erik de Castro Lopo
-----------------------------------------------------------------
Being really good at C++ is like being really good at using rocks to
sharpen sticks." -- Thant Tessman

Erik de Castro Lopo wrote:
> If it helps, this is now in trac:
> 
>     https://trac.xiph.org/ticket/1228
Fixed in SVN 13571.
> Erik
> -- 
> -----------------------------------------------------------------
> Erik de Castro Lopo
> -----------------------------------------------------------------
> Being really good at C++ is like being really good at using rocks to
> sharpen sticks." -- Thant Tessman
> _______________________________________________
> Vorbis-dev mailing list
> Vorbis-dev@xiph.org
> http://lists.xiph.org/mailman/listinfo/vorbis-dev
> 

-- 
-----------------------------------------------------------------
Erik de Castro Lopo
-----------------------------------------------------------------
"The fury with which untenable beliefs are defended is inversely
proportional to their defensibility."
-- Richard Dawkins

On 8/19/07, Erik de Castro Lopo <mle+la@mega-nerd.com>
wrote:
> Fixed in SVN 13571.
Thanks for your help (and patience).