If you receive any compile or link errors when building, double-check that you carefully followed all of the steps in the previous section to specify the include directories, the library directories, the wxWidgets and Win32 libraries, and the correct run-time library. You can also compare the project settings in any of the samples to the settings in your own project, looking for any discrepancies. Some developers start with a sample application’s project file so that most of the settings are already defined correctly.

Some common error messages and solutions include the following:

Visual Studio creates two project configurations, debug and release, when you create a new project. Most wxWidgets developers test their applications using a debug build of wxWidgets to benefit from the debug information and the run-time assertions that may indicate certain problems. You will need to reenter most of the settings for each different project configuration that you use keeping in mind which wxWidgets build the project configuration will be using. To save some time, you can copy one configuration rather than manually re-creating all of the settings each time.

The sample applications have over a dozen project configurations if you want to see how the settings may differ for each configuration.

First, you’ll need to install Bakefile. You can always find the latest version for download at Bakefile’s web site: http://bakefile.sf.net.

It is also available on the CD-ROM included with this book. A binary installer is provided for Windows users, whereas users of Unix-based operating systems will need to unpack the tarball and run Packages for some distributions are also available; check the web site for details.

Before you can build wxWidgets software using Bakefile or any other build system, you need to make sure that wxWidgets is built and that wxWidgets projects can find the wxWidgets includes and library files. wxWidgets build instructions can be found by going to the docs subfolder, then looking for the subfolder that corresponds to your platform (such as msw, gtk, mac) and reading install.txt there. After you’ve done that, the following sections provide some extra steps you should take to make sure your Bakefile projects work with wxWidgets.

Now that everything is set up, it’s time to take Bakefile for a test run. It is recommended that you use the wxWidgets sample bakefile to get started. It can be found in the build/bakefiles/wxpresets/sample directory in the wxWidgets source tree. Here is the minimal.bkl bakefile used in the sample:

It’s a complete sample ready to be baked, so go into the directory mentioned previously and run the following command.

On Windows:

On UNIX:

It should generate a makefile (makefile.vc or GNUmakefile, respectively), which you can use to build the software. You can then build the software using the command nmake -f makefile.vc or make -f GNUmakefile respectively. Now let’s take a look at some of the basic Bakefile concepts that you’ll need to know to move on from here.

As mentioned earlier, Bakefile builds makefiles for many different development environments. The -f option accepts a list of formats that you would like to build, separated by commas. Valid values are shown in Table B-1.

Every project needs to have a target or targets, specifying what is to be built. With Bakefile, you specify the target by creating a tag named with the target type. The possible names for targets are shown in Table B-2.

Note that the previous sample is an “exe” target. After you create the target, all the build settings, including flags and linker options, should be placed inside the target tag as they are in the minimal.bkl sample.

Obviously, you need to be able to add source and include files to your project. You add sources using the <sources> tag (as shown previously), and you add include directories using the <include> tag. You can add multiple <sources> and <include> tags to add multiple source files, or you can add multiple sources and includes into one tag by separating them with a space, like this:

If your sources are in a subfolder of your Bakefile, you use the slash character to denote directories, even on Windows. (For example, src/minimal.cpp.) For more options and flags, please consult the Bakefile documentation in the doc subfolder of Bakefile or on the Bakefile web site.

What if you want to offer a debug and a release build? Or separate Unicode and ANSI builds? You can do this in Bakefile by creating options. To create an option, use the <option> tag. A typical option has three important parts: a name, a default value, and a comma-separated list of values. For example, here is how to create a DEBUG option that builds debug by default:

You can then test the value of this option and conditionally set build settings, flags, and so on. For more information on both options and conditional statements, please refer to the Bakefile documentation.

Most projects will reuse certain settings, or options, in their makefiles, such as DEBUG or static/dynamic library options. Also it is common to have to use settings from another project; for example, any project that uses wxWidgets will need to build using the same flags and options used to build wxWidgets. Bakefile makes these things easier by letting users create Bakefile templates, where you can store common settings.

Bakefile ships with a couple of templates, found in the presets subfolder of your Bakefile installation. The simple.bkl template adds a DEBUG option to makefiles so that you can build in release or debug mode. To add this template to your project, simply add the tag <include file="presets/simple.bkl"/> to the top of your bakefile. Then, when creating your target, add the template="simple" attribute to it. Now, when you have built the makefile, your users can write commands like

or

in order to build the software in debug mode.

To simplify the building of wxWidgets-based projects, wxWidgets contains a set of bakefiles that automatically configure your build system to be compatible with wxWidgets. As you’ll notice in the previous sample, the sample project uses the wx template. After you’ve included the template, your software will now build with wxWidgets support.

Because the wxWidgets presets don’t exist in the Bakefile presets subfolder, Bakefile needs to know where to find these presets. The -I command adds the wxpresets folder to Bakefile’s search path.

If you regularly include Bakefile presets in places other than the Bakefile presets folder, then you can set the BAKEFILE_PATHS environment variable so that Bakefile can find these Bakefiles and include them in your project. This way you no longer need to specify the -I flag each time you build.

Lastly, it’s important to note that the Win32 wx project bakefiles come with some common build options that users can use when building the software. These options are shown in Table B-3.

Note that these options are not needed under Unix because wx-config can be used to specify these options.

If you have a large project, you can imagine that the calls to Bakefile would get more and more complex and unwieldy. For this reason, a script called bakefile_gen was created, which reads in a .bkgen file that provides all the commands needed to build all the makefiles your project supports. A discussion of how to use bakefile_gen is beyond the scope of this tutorial, but it deserves a mention because it can be invaluable to large projects. Documentation on bakefile_gen can be found in the Bakefile distribution.

This concludes our basic tutorial of the cross-platform Bakefile build system management tool. From here, please be sure to take a good look at the Bakefile documentation to see what else it is capable of. Please post questions to the Bakefile mailing list, or if you have questions specific to the wxWidgets template Bakefile, send an email to the wxWidgets mailing list. See the Bakefile and wxWidgets web sites for information on how to subscribe to these lists.

Enjoy using Bakefile!

If you did not install the wxWidgets files into /usr/local, you will need to use wx-config “in-place,” meaning that it will produce absolute paths to that build’s files right from the build directory. This should be done by passing the ---inplace flag to wx-config with whatever flags you are requesting. Even if you did run make install, nothing prevents you from using the in-place flag with a particular build of wxWidgets. When running in-place, you do not need to pass any build configuration parameters because an in-place wx-config knows only about one build, the build from which you are running wx-config in-place.

When you have built and installed multiple configurations of wxWidgets, you can specify to wx-config which configuration’s build flags you would like returned. For example, if you are creating both debug and release builds of your project, you should be sure to get the correct flags for each configuration from wx-config, for example:

or

Many options are available to choose specific build configurations. The most commonly used flags are

You can also retrieve a list of available configurations using wx-config –list.

A full list of flags is available by using wx-config --help.