On Thu, Dec 12, 2013 at 02:14:19AM +1000, Allan McRae wrote:
> On 12/12/13 00:24, Jeremy Heiner wrote:
> > On Tue, Dec 10, 2013 at 11:58 PM, Allan McRae <[email protected]> wrote:
> >> I am still looking for something cleaner than
> >> the proposed #define/#undef approach which feels a bit hacky
> >
> > Here is a third (well, 4th, since "do nothing" is always on the table)
> > option which lies between "just document" and "macro shenanigans"...
> > Following the lead of 'alpm_capabilities', add:
> >
>
> How about #5...
>
>
> diff --git a/lib/libalpm/alpm.c b/lib/libalpm/alpm.c
> index 878c38b..a41c07d 100644
> --- a/lib/libalpm/alpm.c
> +++ b/lib/libalpm/alpm.c
> @@ -52,6 +52,12 @@ alpm_handle_t SYMEXPORT *alpm_initialize(const char
> *root, const char *dbpath,
> const char *lf = "db.lck";
> size_t lockfilelen;
> alpm_handle_t *myhandle = _alpm_handle_new();
> +
> + /* calculate off_t size at runtime */
> + size_t off_t_size = ((char *)((off_t *)0 + 1) - (char *)(off_t *)0);
> +
> + if(off_t_size != sizeof(off_t)) {
> + myerr = ALPM_ERR_OFF_T_SIZE;
> + goto cleanup;
> + }
I do not believe this actually works as intended. There's nothing "at
runtime" about this, especially when optimizations are involved (even
with -O1). Your off_t_size will be calculated at compile time and
therefore the comparison that follows will never fail. The instructions
generated for the off_t_size is effectively:
mov $0x8,%eax
Or, when LFS isn't enabled:
mov $0x4,%eax
d
>
> if(myhandle == NULL) {
> myerr = ALPM_ERR_MEMORY;
> diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
> index 5fa775c..f61e3f5 100644
> --- a/lib/libalpm/alpm.h
> +++ b/lib/libalpm/alpm.h
> @@ -1333,6 +1333,7 @@ typedef enum _alpm_errno_t {
> /* Misc */
> ALPM_ERR_RETRIEVE,
> ALPM_ERR_INVALID_REGEX,
> + ALPM_ERR_OFF_T_SIZE,
> /* External library errors */
> ALPM_ERR_LIBARCHIVE,
> ALPM_ERR_LIBCURL,
> diff --git a/lib/libalpm/error.c b/lib/libalpm/error.c
> index 8622180..1aed1a1 100644
> --- a/lib/libalpm/error.c
> +++ b/lib/libalpm/error.c
> @@ -145,6 +145,8 @@ const char SYMEXPORT *alpm_strerror(alpm_errno_t err)
> return _("failed to retrieve some files");
> case ALPM_ERR_INVALID_REGEX:
> return _("invalid regular expression");
> + case ALPM_ERR_OFF_T_SIZE:
> + return _("incompatible off_t size");
> /* Errors from external libraries- our own wrapper error */
> case ALPM_ERR_LIBARCHIVE:
> /* it would be nice to use archive_error_string() here,
> but that
>
>
>
