[PD-dev] how to cast printed pointers? (commit c019784b83 throwing warnings)

[Albert Rafetseder]

> After merging commit c019784b83 (get rid of a 3 more bogus (unsigned long) casts)

(Link to commit for reference: [0] )

> I'm now getting compiler warnings like this:
> 
> g_editor.c:1884:73: warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘struct _glist *’ [-Wformat=]
>  1884 |             snprintf(cbuf, MAXPDSTRING - 2, "pdtk_canvas_setparents .x%lx", c);
>       |                                                                       ~~^   ~
>       |                                                                         |   |
>       |                                                                         |   struct _glist *
>       |                                                                         long unsigned int
> 
> 
> ..
> I presume there's a good reason to change the code (what if "long" is the wrong
> size?) but I'd like to figure out a way to do it that doesn't throw warnings.

My C has oxidized substantially over time, but I think the p conversion
specifier might be the correct thing to use -- if you can live with the
additional leading "0x" that is caused by its implied "alternate form"
flag, `#`.

>From `man snprintf` on Linux / OS X:

"""
p       The void * pointer argument is printed in hexadecimal (as if by
             `%#x' or `%#lx').
"""

Trying with the current master [1] which includes the commit above, the
change from `%lx` to `%p` in lines 1884 and 1891 in `g_editor.c` fixes
the warning. (Other warnings/errors remain, and I wouldn't have a clue
what to test to check the outcome anyway.)

Best,
  Albert.

[0]
https://github.com/pure-data/pure-data/commit/c019784b83f6638a1c4090ce27e6a0036b6bacaa
[1]
https://github.com/pure-data/pure-data/commit/364d859aa29c1d42be1d42ad81c74bc2fbc76cca