forked from bartvdbraak/blender
9b239883f0
* if you all look to the left, you won't see that on the right BF_PRIORITYLIST was spelled BF_PRIORITY_LIST twice.
195 lines
8.6 KiB
Plaintext
195 lines
8.6 KiB
Plaintext
$Id$
|
|
|
|
|
|
Internals of Blenders SCons scripts
|
|
===================================
|
|
|
|
Scope
|
|
------
|
|
This document describes the architecture of the SCons scripts for
|
|
Blender. An overview of available functionality and how to modify,
|
|
extend and maintain the system.
|
|
|
|
Audience
|
|
--------
|
|
This document is for developers who need to modify the system,
|
|
ie. add or remove new libraries, add new arguments for SCons, etc.
|
|
|
|
Files and their meaning
|
|
-----------------------
|
|
|
|
The main entry point for the build system is the SConstruct-file in
|
|
$BLENDERHOME. This file creates the first BlenderEnvironment to work
|
|
with, reads in options, and sets up some directory structures. Further
|
|
it defines some targets.
|
|
|
|
Platform-specific configurations are in $BLENDERHOME/config. The
|
|
filenames have the form (platform)-config.py, where platform one of:
|
|
|
|
* darwin
|
|
* linux2
|
|
* win32-mingw
|
|
* win32-vc
|
|
|
|
The user can override options by creating a file
|
|
$BLENDERHOME/user-config.py. It can have any option from
|
|
(platform)-config.py. Options in this file will override the platform
|
|
defaults.
|
|
|
|
Much of the actual functionality can be found in the python scripts
|
|
in the directory $BLENDERHOME/tools, with Blender.py defining the
|
|
bulk of the functionality. btools.py has some helper functions, and
|
|
bcolors.py is for the terminal colours. mstoolkit.py and crossmingw.py
|
|
are modules which set up SCons for the MS VC++ 2003 toolkit and
|
|
the cross-compile toolset for compiling Windows binaries on Linux
|
|
respectively. Note: the cross-compile doesn't work yet for Blender,
|
|
but is added in preparation for having it work in the distant future.
|
|
|
|
BlenderEnvironment
|
|
------------------
|
|
|
|
The module Blender.py implements a BlenderEnvironment class, derived
|
|
from the SConsEnvironment of SCons. This is done to wrap some often
|
|
used functionality. The BlenderEnvironment offers two important
|
|
wrappers: BlenderProg() and BlenderLib(). The first one is used to
|
|
specify a binary to be built, the second one is used to specify what
|
|
static library is built from given sources.
|
|
|
|
Build a static library called "somelib". The system handles library
|
|
pre- and suffixes automatically, you don't need to bother yourself
|
|
with these details:
|
|
|
|
env = BlenderEnvironment(ENV = os.environ) # create an environment
|
|
env.BlenderLib(libname="somelib", sources=['list.c','with.c','sources.c'],
|
|
includes=['/list/with/include/paths', '.', '..'],
|
|
defines=['LIST_WITH', 'CPP_DEFINES', 'TO_USE'],
|
|
libtype=['blender', 'common'] # this is a list with libtypes. Normally you don't
|
|
# need to specify this, but if you encounter linking
|
|
# problems you may need this
|
|
priority=[10, 20] # Priorities, list as long as libtype, priority per type
|
|
compileflags=['/O2'] # List of compile flags needed for this particular library.
|
|
# used only in rare cases, like SOLID, qhull and Bullet
|
|
)
|
|
|
|
There should be no need to ever add an extra BlenderProg to the
|
|
existing ones in SConstruct, see that file for its use, and Blender.py
|
|
for its implementation.
|
|
|
|
The new system works so that using these wrappers, has all libraries
|
|
(and programs) register with a central repository. This means that
|
|
adding a new library is as easy as just creating the new SConscript
|
|
and making sure that it gets called properly. Linking and such will
|
|
then be handled automatically.
|
|
|
|
If you want that adding new source files for a certain library
|
|
is handled automatically, you can use the Glob() function from
|
|
the BlenderEnvironment to create lists of needed files. See
|
|
$BLENDERHOME/source/blender/src/SConscript for an example. Keep in
|
|
mind that this will add any new file that complies to the rule given
|
|
to the Glob() function. There are a few (external) libraries with
|
|
which this can't be used, because it'd take files that shouldn't be
|
|
compiled, and create subsequentially problems during the linking stage
|
|
(like SOLID, qhull, Bullet).
|
|
|
|
Linking order and priorities
|
|
----------------------------
|
|
|
|
As shown above, you can give a library a priority in a certain
|
|
group. If you need to make sure that a Blender library is linked
|
|
before or after another one, you can give it a priority. To debug
|
|
the priorities us BF_PRIORITYLIST=1 on the command-line while running
|
|
a build.
|
|
|
|
% scons BF_PRIORITYLIST=1
|
|
|
|
This will give a list with values suggested by the system. Make
|
|
changes to all SConscripts in question to reflect or change the
|
|
values given by this command. ALWAYS check this after adding a new
|
|
internal, external library or core library, and make sure there are
|
|
sane values. You can use large and negative numbers to test with,
|
|
but after you've got a working linking order, do change the system
|
|
to reflect BF_PRIORITYLIST values.
|
|
|
|
Also, if you find that a library needs to be given multiple times to
|
|
the linker, you can do that by giving a python list with the names
|
|
of the available library types. They are currently:
|
|
|
|
B.possible_types = ['core', 'common', 'blender', 'intern',
|
|
'international', 'game', 'game2',
|
|
'player', 'player2', 'system']
|
|
|
|
More groups can be added, but that should be carefully considered,
|
|
as it may lead to large-scale changes. The current amount of libraries
|
|
should suffice.
|
|
|
|
The central repository is utilised in the SConstruct in two
|
|
ways. Firstly, it is used to determine the order of all static
|
|
libraries to link into the main Blender executable. Secondly, it
|
|
is used to keep track of all built binaries and their location,
|
|
so that they can be properly copied to BF_INSTALLDIR.
|
|
|
|
The libraries can be fetched in their priority order with
|
|
create_blender_liblist from Blender.py, see the SConstruct on how
|
|
it is used.
|
|
|
|
The program repository is the global list program_list from
|
|
Blender.py. See SConstruct for its usage.
|
|
|
|
|
|
Adding a new option and libraries
|
|
---------------------------------
|
|
|
|
Lets say we want to add WITH_BF_NEWLIB, which will
|
|
enable or disable a new feature library with sources in
|
|
$BLENDERHOME/source/blender/newlib. This 'newlib' needs external
|
|
headers from a 3rd party library '3rdparty'. For this we want to
|
|
add a set of options BF_3RDPARTY, BF_3RDPARTY_INC, BF_3RDPARTY_LIB,
|
|
BF_3RDPARTY_LIBPATH:
|
|
|
|
1) Add all mentiond options to all (platform)-config.py
|
|
files. WITH_BF_NEWLIB is a boolean option ('true', 'false'),
|
|
the rest are strings with paths and library names. See the
|
|
OpenEXR options for example.
|
|
|
|
2) Add all options to the argument checking function
|
|
validate_arguments() in btools.py. See again OpenEXR options
|
|
for example.
|
|
|
|
3) Add all options to the option reading function read_opts()
|
|
in btools.py. See again OpenEXR options for example. All default
|
|
values can be empty, as the actual default values are in the
|
|
(platform)-config.py files.
|
|
|
|
4) Add BF_3RDPARTY_LIB to the function setup_syslibs()
|
|
and BF_3RDPARTY_LIBPATH to the function setup_staticlibs()
|
|
in Blender.py
|
|
|
|
At this stage we have prepared all option setting and linking needs,
|
|
but we still need to add in the compiling of the 'newlib'.
|
|
|
|
5) Create a SConscript in $BLENDERHOME/source/blender/newlib. Look
|
|
at ie. $BLENDERHOME/source/blender/src/SConscript for
|
|
template. The new SConscript will register the new library
|
|
like so:
|
|
|
|
env.BlenderLib(libname='newlib', sources=sourcefiles, includes=incs) # the rest of the arguments get defaults = empty lists and values
|
|
|
|
6) Edit $BLENDERHOME/source/blender/SConscript with the following
|
|
addition:
|
|
|
|
if env['WITH_BF_NEWLIB'] == 1:
|
|
SConscript(['newlib/SConscript'])
|
|
|
|
After this you can see if this works by trying to build:
|
|
|
|
% scons WITH_BF_NEWLIB=1 # build with newlib
|
|
% scons WITH_BF_NEWLIB=0 # disable newlib
|
|
|
|
This is all what should be needed. Changing the library name doesn't
|
|
need changes elsewhere in the system, as it is handled automatically
|
|
with the central library repository.
|
|
|
|
Enjoy the new system!
|
|
|
|
/Nathan Letwory (jesterKing)
|