[pacman-dev] libarchive version check

[Dan McGee]

On Wed, May 14, 2008 at 7:33 AM, Xavier <shiningxc at gmail.com> wrote:
> On Wed, May 14, 2008 at 2:14 PM, Dan McGee <dpmcgee at gmail.com> wrote:
>>
>> On Wed, May 14, 2008 at 6:50 AM, Xavier <shiningxc at gmail.com> wrote:
>>  > On Wed, May 14, 2008 at 1:16 PM, Allan McRae <mcrae_allan at hotmail.com> wrote:
>>  >> Can we add a check on the libarchive version number when configuring
>>  >>  pacman.  You can run configure without a problem with a libarchive 1.x
>>  >>  version but not actually complete the build. See
>>  >>  http://bbs.archlinux.org/viewtopic.php?pid=367593
>>  >>
>>  >>  I know next to nothing about libarchive so I am giving this to someone
>>  >>  else to take care of!
>>  >>
>>  >
>>  > I doubt many ppl are still trying to build pacman with libarchive 1.x.
>>  > Yeah, one did but well..
>>  > But in any cases, I am curious to know how to check version number at
>>  > configure time. I don't know how to do it either.
>>  > Though I believe I know one way to prevent the specific error that
>>  > user was having. We could replace this stuff in configure.ac :
>>  > # Check for libarchive
>>  > AC_CHECK_LIB([archive], [archive_read_data], ,
>>  >  AC_MSG_ERROR([libarchive is needed to compile pacman!]))
>>  > by this :
>>  > # Check for libarchive
>>  > AC_CHECK_LIB([archive], [archive_read_open_filename], ,
>>  >  AC_MSG_ERROR([libarchive is needed to compile pacman!]))
>>  >
>>  > What I don't know is when this read_open_filename function was introduced.
>>  > And also what is the oldest libarchive version with which pacman is
>>  > guaranteed to work.
>>
>>  I would suggest someone grab the last libarchive 1.X release and the
>>  first libarchive 2.X release and compare the header files. See if
>>  there is an new function introduced in 2.X that we can use instead to
>>  verfiy you are using a new enough version.
>>
>
> Actually it's silly, this archive_read_open_filename function appeared
> between 1.2.38 and 1.2.57, the two only 1.2.x releases left there :
> http://people.freebsd.org/~kientzle/libarchive/src/
> That 1.2.53 version this guy was using on debian doesn't even exist
> anymore. And that's indeed the version debian stable is using.
> (testing has 2.4.11 and unstable has 2.4.17).
>
> I don't know if pacman would work with 1.2.57 :P

Between 1.3.1 and 2.0.20, we have the following new functions (diff
the headers):
int		 archive_read_support_format_empty(struct archive *);
int		 archive_write_finish_entry(struct archive *);
void		 archive_clear_error(struct archive *);

struct archive	*archive_write_disk_new(void);
/* This file will not be overwritten. */
int		 archive_write_disk_set_skip_file(struct archive *,
		     dev_t, ino_t);
/* Set flags to control how the next item gets created. */
int		 archive_write_disk_set_options(struct archive *,
		     int flags);


Of course, we don't really use any of those in our code, but they
would be able to tell us the difference between 1.X and 2.X. We do
write things to disk, so checking for archive_write_disk_new might not
be a terrible idea.

-Dan