Re: libnettle/libhogweed WIP

[Eli Zaretskii]

> From: Ted Zlatanov <address@hidden>
> Date: Mon, 17 Apr 2017 13:34:00 -0400
> 
>     USE_SAFE_ALLOCA;
>     unsigned char *storage = SAFE_ALLOCA (storage_length);
> 
> gnutls.c: In function ‘gnutls_symmetric_aead’:
> gnutls.c:1839:45: warning: pointer targets in passing argument 1 of 
> ‘make_unibyte_string’ differ in signedness [-Wpointer-sign]
>    Lisp_Object output = make_unibyte_string (storage, storage_length);
>                                              ^~~~~~~
> In file included from gnutls.c:23:0:
> lisp.h:3583:20: note: expected ‘const char *’ but argument is of type 
> ‘unsigned char *’
>  extern Lisp_Object make_unibyte_string (const char *, ptrdiff_t);
>                     ^~~~~~~~~~~~~~~~~~~

You need to declare/initialize 'storage' like this:

  char *storage = SAFE_ALLOCA (storage_length);

> In file included from gnutls.c:23:0:
> lisp.h:4425:47: warning: variable ‘sa_must_free’ set but not used 
> [-Wunused-but-set-variable]
>    ptrdiff_t sa_count = SPECPDL_INDEX (); bool sa_must_free = false
>                                                ^
> gnutls.c:1769:3: note: in expansion of macro ‘USE_SAFE_ALLOCA’
>    USE_SAFE_ALLOCA;
>    ^~~~~~~~~~~~~~~
> lisp.h:4425:13: warning: unused variable ‘sa_count’ [-Wunused-variable]
>    ptrdiff_t sa_count = SPECPDL_INDEX (); bool sa_must_free = false
>              ^
> gnutls.c:1769:3: note: in expansion of macro ‘USE_SAFE_ALLOCA’
>    USE_SAFE_ALLOCA;
>    ^~~~~~~~~~~~~~~

Not sure why this happens: SAFE_FREE uses these variables.  Perhaps
because you didn't call SAFE_FREE before the first 'return'?  Or maybe
it's a side effect of the warning?