[PATCH v1] erofs-utils: Fix cross compile with autoconf

[Gao Xiang]

Hi Sandeep,

On 2023/10/7 22:51, Sandeep Dhavale wrote:
> On Sat, Oct 7, 2023 at 1:25 AM Gao Xiang <hsiangkao at linux.alibaba.com> wrote:

...

>>
> Hi Gao,
> That cannot work because AS_RUN_IFELSE() is only invoked if
> MAX_BLOCK_SIZE is not set.
> 
>    # Detect maximum block size if necessary
>    AS_IF([test "x$MAX_BLOCK_SIZE" = "x"], [
>      AC_CACHE_CHECK([sysconf (_SC_PAGESIZE)], [erofs_cv_max_block_size],
>                   AC_RUN_IFELSE([AC_LANG_PROGRAM(
>    [[
>    #include <unistd.h>
>    #include <stdio.h>
> ...
> 
> Cross compilation works if MAX_BLOCK_SIZE is set today as is without
> any fix. Cross compilation only fails when MAX_BLOCK_SIZE is not set
> AND the configure script tries to detect because there is no action
> defined regarding what should be erofs_cv_max_block_size.

Yes, I know MAX_BLOCK_SIZE is not set here. My only concern is that
hardcoded 4096 is involved many times.

I've applied this original version. But I think we might need to
clean up multiple 4096 later...

Thanks,
Gao Xiang

> 
> Thanks,
> Sandeep.