[PATCH v2 2/4] erofs-utils: introduce build support for libcurl, openssl and libxml2 library

[zhaoyifan (H)]

On 2025/8/1 15:39, Gao Xiang wrote:
>
>
> On 2025/8/1 15:30, Yifan Zhao wrote:
>> From: zhaoyifan <zhaoyifan28 at huawei.com>
>>
>> This patch adds additional dependencies on libcurl, openssl and 
>> libxml2 library
>> for the upcoming S3 data source support, with libcurl to interact 
>> with S3 API,
>> openssl to generate S3 auth signature and libxml2 to parse response 
>> body.
>>
>> The newly introduced dependencies are optional, controlled by the 
>> `--enable-s3`
>> configure option.
>
> Use 72-char per line at maximum...
>
Fixed in this and other 3 patches. Thanks for pointing it out!
>>
>> Signed-off-by: Yifan Zhao <zhaoyifan28 at huawei.com>
>> ---
>> change since v1:
>> - rebase on the latest `experimental` branch
>> - rename: lib/s3.c => lib/remotes/s3.c
>> - configure.ac: introduce `subdir-objects` option as s3.c in a subdir
>> - move include/erofs/s3.h in the following patch
>>
>>   configure.ac     | 43 ++++++++++++++++++++++++++++++++++++++++++-
>>   lib/Makefile.am  |  4 ++++
>>   lib/remotes/s3.c |  6 ++++++
>>   mkfs/Makefile.am |  3 ++-
>>   4 files changed, 54 insertions(+), 2 deletions(-)
>>   create mode 100644 lib/remotes/s3.c
>>
>> diff --git a/configure.ac b/configure.ac
>> index 2d42b1f..82ff98e 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -24,7 +24,7 @@ esac
>>   # OS-specific treatment
>>   AM_CONDITIONAL([OS_LINUX], [test "$build_linux" = "yes"])
>>   -AM_INIT_AUTOMAKE([foreign -Wall])
>> +AM_INIT_AUTOMAKE([foreign subdir-objects -Wall])
>>     # Checks for programs.
>>   AM_PROG_AR
>> @@ -165,6 +165,10 @@ AC_ARG_WITH(xxhash,
>>      [AS_HELP_STRING([--with-xxhash],
>>         [Enable and build with libxxhash support 
>> @<:@default=auto@:>@])])
>>   +AC_ARG_ENABLE(s3,
>> +   [AS_HELP_STRING([--enable-s3], [enable s3 image generation 
>> support @<:@default=no@:>@])],
>> +   [enable_s3="$enableval"], [enable_s3="no"])
>> +
>>   AC_ARG_ENABLE(fuse,
>>      [AS_HELP_STRING([--enable-fuse], [enable erofsfuse 
>> @<:@default=no@:>@])],
>>      [enable_fuse="$enableval"], [enable_fuse="no"])
>> @@ -578,6 +582,32 @@ AS_IF([test "x$with_xxhash" != "xno"], [
>>     ])
>>   ])
>>   +AS_IF([test "x$enable_s3" != "xno"], [
>> +  # Paranoia: don't trust the result reported by pkgconfig before 
>> trying out
>> +  saved_LIBS="$LIBS"
>> +  saved_CPPFLAGS=${CPPFLAGS}
>> +  PKG_CHECK_MODULES([libcurl], [libcurl])
>> +  PKG_CHECK_MODULES([openssl], [openssl])
>> +  PKG_CHECK_MODULES([libxml2],  [libxml-2.0])
>
>
> I wonder if it's possible to introduce
> `--with-libcurl`
> `--with-openssl`
> `--with-libxml`
>
> and `--enable-s3`, and if users disable any library,
> it should fail.
>
> I think why it should behave as this, because libcurl
> openssl and libxml can be used for other use cases
> (e.g. oci registry support), users can always link
> these libs
>
Done. Introduce `--with-{libcurl,openssl,libxml2}` options,

and `--enable-s3` would fail if any of them is not satisfied.


IMHO, we should use --with-libxml2 instead of --with-libxml

here as this is its official name. Please point it out if I'm wrong.


Thanks,

Yifan Zhao

> Thanks,
> Gao Xiang