BUILDING SAMBA 4.0
===================================

The waf build
-------------

Samba 4.0 ships with a new build system, based on waf.  A background to
this build system can be found at https://wiki.samba.org/index.php/Waf

This is the build system that is used when you run ./configure && make
in the top level of a Samba 4.0 release tree.

For the vast majority of our users, this is the build system you should
use.  It supports parallel and incremental builds, and builds the whole
Samba suite, the file server, the print server, the NT4 domain
controller, winbind, the AD Domain Controller, the client libraries and
the python libraries.  

A key feature for many of our distributors and OEMs is that despite the
range of additional features, the resulting binaries and libraries are
substantially smaller, because we use shared libraries extensively. 

For distributions that have a requirement to use the system-supplied
Kerberos library, we support building against a Heimdal or system MIT
Kerberos library, provided the version is recent enough (otherwise we
will use our internal version of Heimdal).  Please note that builds
with MIT krb5 support will not have AD DC features.

Where we provide a tool under a name that was used in Samba 3.x, it
continues to behave in the same way it always has.  This will ensure
that our change in build system does not impact on our user's ability
to use Samba as they always have.

For developers, this build system backs a comprehensive 'make test',
which provides code coverage of around 48% of our code by line:
https://build.samba.org/lcov/data/coverage/samba_4_0_test/

This build system also implements important features such as ABI
checking (which protects you as users from accidental changes to our
published libraries), symbol versions and dependency checked incremental
rebuilds after header-file changes. 

The waf build also assists developers by providing fully-linked binaries
that run from bin/ without needing to set LD_LIBRARY_PATH. 

For users who do not have python installed on their systems, we provide
a install_with_python.sh script, which will install a local copy of
python sufficient to run the build system, without impacting on the rest
of the system.  

Within this requirement, we expect that this build will run on all our
supported platforms, and will actively deal with any portability issues
that users can bring to our attention. 

For all these reasons, we highly recommend this new build system to all
our users, for whatever purpose you want to put Samba to.

The autoconf build
------------------

The autoconf build was removed in Samba 4.1.  If you have tried and
failed to use our waf build system, you may wish to use the latest
supported 4.0 release instead, while we address your use case.

Optional Libraries
------------------

To assist users and distributors to build Samba with the full feature
set, we hope to in the future the build system will abort if our
dependent libraries and their header files are not found on the target
system.  This will mean for example, that xattr, acl and ldap headers
must be installed for the default build to complete.  The configure
system will check for these headers, and the error message will
indicate:
 - the required header and library
 - the option (such as --without-acl-support) that can be specified to
   skip this requirement, and
 - the feature (ACL support optional for file servers, mandatory for AD
   Domain Controller) being skipped. 

This will assist users and in particular distributors in building fully
functional packages, while allowing those on systems truly without these
facilities to continue to build Samba after careful consideration.

Sadly this feature is still pending implementation.
