wxWidgets/docs/contributing/how-to-add-files-to-build-system.md

How to add new files and libraries to wxWidgets build system

Regenerating makefiles

wxWidgets uses the legacy 0.2 branch Bakefile to generate native makefiles.

Currently the latest version from legacy-0.2-branch must be used, so you need to compile it from source, which requires Python 2 headers and libraries.

Once you have installed Bakefile, you can easily regenerate the makefiles using the bakefile_gen tool. Run it from $(wx)/build/bakefiles directory and it will regenerate all outdated makefiles. See $(wx)/build/bakefiles/README for more details.

Note that it generates makefiles for samples, too.

IMPORTANT NOTE: Don't forget to run autoconf in wxWidgets root directory (after running Bakefile) if you changed any conditional variable or target condition in .bkl files! You will know that this happened if $(wx)/autoconf_inc.m4 content changed.

You can use Bakefile to generate makefiles or projects customized to your needs, too. See Bakefiles.bkgen for details on bakefile commands used to generate makefiles. For example, you can use this command to generate VC++ project files without wxUniversal configurations:

bakefile -v -fmsvc6prj -o../wxmy.dsw -DRUNTIME_LIBS=dynamic
         -DDEBUG_INFO=default -DDEBUG_FLAG=default
         -DOFFICIAL_BUILD=0 -DUSE_HTML=1 -DUSE_OPENGL=1
         -DMONOLITHIC=0 -DUSE_GUI=1 -DWXUNIV=0 wx.bkl

Or monolithic instead of multilib (the default):

bakefile -v -fmsvc6prj -o../wxmono.dsw -DRUNTIME_LIBS=dynamic
         -DDEBUG_INFO=default -DDEBUG_FLAG=default
         -DOFFICIAL_BUILD=0 -DUSE_HTML=1 -DUSE_OPENGL=1
         -DMONOLITHIC=1 -DUSE_GUI=1 wx.bkl

Or monolithic wxBase:

bakefile -v -fmsvc6prj -o../wxBase.dsw -DRUNTIME_LIBS=dynamic
         -DDEBUG_INFO=default -DDEBUG_FLAG=default
         -DOFFICIAL_BUILD=0 -DUSE_HTML=0 -DUSE_OPENGL=0
         -DMONOLITHIC=1 -DUSE_GUI=0 wx.bkl

It is, however, recommended to modify Bakefiles.bkgen (or Bakefiles.local.bkgen) by means of <add-flags> and <del-flags> directives and use bakefile_gen instead of running bakefile directly.

Bakefile files organization

Makefile are generated from .bkl files ("bakefiles") from two places:

• $(wx)/build/bakefiles directory
• samples directories

$(wx)/build/bakefiles contains bakefiles for main library and support files that simplify writing bakefiles for samples.

Support files are:

• wxwin.py - helper functions
• common.bkl
• common_samples.bkl
• config.bkl - user-configurable build options
• make_dist.mk - implementation of "make dist" on Unix

Files used to build the library are:

• wx.bkl - main file
• files.bkl - lists of source files
• monolithic.bkl - targets for wxWin built as single big library
• multilib.bkl - targets for multilib build
• opengl.bkl - GL library with wxGLCanvas (this one is not included in monolithic library for historical reasons, so "monolithic" really means "two libs")
• {expat,jpeg,png,tiff, regex,zlib,odbc}.bkl - 3rd party libraries makefiles

Adding files to existing library

UPDATE: files.bkl is now itself partially generated from the master file build/files. If the variable which you need to modify, according to the instructions below, is already defined in build/files, update it there and run build/upmake to update files.bkl.

All files used by main libraries are listed in files.bkl. The file is organized into variables for toolkits, platforms and libraries. The variables come in pairs: there's always FOO_SRC for source files and FOO_HDR for header files. Platform or toolkit specific files are grouped together in variable with platform or toolkit name in them, e.g. BASE_WIN32_SRC, BASE_UNIX_SRC, GTK_SRC, MOTIF_SRC.

Note: A side effect of this toolkit-centric organization is that one file may be present several times in files.bkl in different contexts.

When you are adding a file, you must put it into appropriate variable. This is easy if you are adding the file to library that is always built from same sources on all platforms (e.g. wxXml or wxXML) -- simply add the file to e.g. HTML_SRC or HTML_HDR.

If the file is used only on one platform and is part of wxBase, add it to BASE_{platform}_SRC/HDR. If it is used on all platforms, add it to BASE_CMN. If it is built on more than one platform but not on all of them, add the file to all platforms that use it!

If a file is not wxBase file, but GUI file, then the variables are named after toolkits/ports, not platforms. Same rules as for wxBase files apply (substitute "platform" with "toolkit"). Make sure you correctly choose between {port}_LOWLEVEL_SRC and {port}_SRC -- the former is for files used by wxUniversal, e.g. GDI classes. Files shared by all X Window System ports should be put into XWIN_LOWLEVEL_SRC.

Adding sample

Copy the bakefile from another sample, change the ID and files accordingly. If the sample uses some data files, make sure to have <wx-data> node in the sample's bakefile (see e.g. samples/image/image.bkl for an example). Make sure to add <wx-lib> statements for all libraries from multilib build that are required by the sample.

The Windows resource specification should use the central .rc file:

    <win32-res>../sample.rc</win32-res>

Run bakefile_gen in $(wx)/build/bakefiles to regenerate the bakefiles.

Finally commit $(wx)/build/bakefiles/make_dist.mk and all the other modified files.

Currently we commit all the generated makefiles.

Adding new core library

When adding new library to the core set of libraries, the files must be added to both a newly added library in multilib build and into the single library built in monolithic mode. We will assume that the new library is called wxFoo.

a) Add files to files.bkl:

• If wxFoo builds from same files on all platforms (e.g. wxNet), add FOO_SRC and FOO_HDR variables with lists of sources and headers.
• If wxFoo have no files in common (e.g. wxGL), add FOO_SRC and FOO_HDR with toolkit or platform conditions. Have a look at OPENGL_SRC for an example.
• Otherwise add FOO_CMN_SRC and FOO_CMN_HDR for common files and FOO_{platform}_{SRC,HDR} or FOO_{toolkit}_{SRC,HDR} as appropriate. Add FOO_PLATFORM_{SRC,HDR} into "Define sources for specific libraries" section that is conditionally set to one of FOO_xxx_{SRC,HDR} based on target platform/toolkit (see NET_PLATFORM_SRC definition for an example). Finally, define FOO_SRC and FOO_HDR to contain both FOO_PLATFORM_{SRC,HDR} and FOO_{SRC,HDR} (see NET_SRC definition for an example).
• Add FOO_HDR to ALL_GUI_HEADERS or ALL_BASE_HEADERS.
• If wxFoo is wxBase library (doesn't use GUI), add FOO_SRC to ALL_BASE_SOURCES.

(You can apply different approaches to HDR and SRC variables, if e.g. headers are all common but sources are not.)

Note that the conditions can only test for equality, due to limitations of native make tools.

b) Modify bakefile system in build/bakefiles/ to recognize wxFoo:

• Add 'foo' to MAIN_LIBS and LIBS_NOGUI or LIBS_GUI (depending on whether the library depends on wxCore or not) to wxwin.py file.

• Add extra libraries needed by wxFoo (if any) to EXTRALIBS in wxwin.py

• Add WXLIB_FOO definition to common.bkl (into the "Names of component libraries" section). It looks like this:

  $(mk.evalExpr(wxwin.mkLibName('foo')))

c) Modify monolithic.bkl to add files to monolithic build: it's enough to add FOO_SRC to MONOLIB_GUI_SRC or MONOLIB_SRC, depending on whether wxFoo uses GUI or not.

d) Modify multilib.bkl to add files to multilib build: add foolib and foodll targets. Don't use wxBase targets as the template, use e.g. wxXML or wxHTML. Make sure WXMAKINGDLL_FOO is defined in foodll.

e) Regenerate all makefiles (don't forget to run autoconf)

f) Update configure.in and wx-config.in to contain information about the library and needed linker flags:

• Add "foo" to BUILT_WX_LIBS in configure.in.
• If appropriate, but it rarely is, so normally this should not be done, add "foo" to either STD_BASE_LIBS or STD_GUI_LIBS in configure.in.
• If wxFoo links against additional libraries, add necessary linker flags and libraries to ldflags_foo and ldlibs_foo variables in wx-config.in (both are optional).

g) Update dlimpexp.h to define WXMAKINGDLL_FOO if WXMAKINGDLL is defined (add #define WXMAKINGDLL_FOO inside first #ifdef WXMAKINGDLL block in dlimpexp.h) and to define WXDLLIMPEXP_FOO and WXDLLIMPEXP_DATA_FOO. You can copy e.g. WXDLLIMPEXP_NET definition, it is something like this:

    #ifdef WXMAKINGDLL_NET
        #define WXDLLIMPEXP_NET WXEXPORT
        #define WXDLLIMPEXP_DATA_NET(type) WXEXPORT type
    #elif defined(WXUSINGDLL)
        #define WXDLLIMPEXP_NET WXIMPORT
        #define WXDLLIMPEXP_DATA_NET(type) WXIMPORT type
    #else // not making nor using DLL
        #define WXDLLIMPEXP_NET
        #define WXDLLIMPEXP_DATA_NET(type) type
    #endif

Don't forget to add WXDLLIMPEXP_FWD_FOO definitions too. Use WXDLLIMPEXP_FOO when declaring wxFoo classes and functions.

h) Add this code to one of wxFoo's files (the more often used, the better):

  // DLL options compatibility check:
  #include "wx/app.h"
  WX_CHECK_BUILD_OPTIONS("wxFoo")

i) Add information about wxFoo to the manual ("Libraries list" section in libs.tex) and update docs/latex/wx/libs.dia (you need Dia for this) to show the dependencies of the new library.

j) Also please add #pragma comment(lib, "foo") (for all build configuration combinations) to the file include/msvc/wx/setup.h and add a check for WXMAKINGDLL_FOO to the test whether we're building a DLL at the end of include/wx/msw/chkconf.h.