Makefile.am HOWTO

(Originally found at http://techbase.kde.org/Development/Tutorials/KDE3/Makefile.am under CC-SA 3.0 and/or GNU FDL 1.2)

Introduction

Original Author: David Faure (faure@kde.org)

This is the Makefile.am HOWTO (English version). Makefile.am is a file used to describe how to build KDE programs. Usually each subdirectory in a KDE module has a Makefile.am. As you may guess from the name, it is supposed to be similar to a Makefile, but it processed first by the KDE build system, then by the autotools to generate the final Makefile.

This is the build system for KDE 3. KDE 4 uses a different build system, CMake. (Trinity, as of May 2014, is in the middle of a Makefile.am -> cmake conversion.)

Makefile.am for a simple program

# Notice the bin_ prefix.
bin_PROGRAMS = kdialog
 
kdialog_SOURCES = kdialog.cpp widgets.cpp
kdialog_LDADD = $(LIB_KIO)
kdialog_LDFLAGS = $(all_libraries) $(KDE_RPATH)
 
AM_CPPFLAGS = $(all_includes)
 
METASOURCES = AUTO

bin

bin means that you want to create something that will install into the bin directory of KDE. *_PROGRAMS means you want to compile a program. Use _SCRIPTS for scripts, etc. Then you can see the name of the program, which is what is used in the lines below to define what has to be done to create that program.

_SOURCES

You list all of the source files that need to be compiled for each of the PROGRAMS you have listed. Don't include header files or other files that don't need processed in the build procedure.

_LDADD

This variable is used for each program to define the libraries that the program links to. You can use three types of libraries references:

• A library reference as you would pass it to gcc. (Like -lfoo)
• A relative path to a Libtool library (Like ../path/to/thelib.la).
• A library macro set by the KDE build system. (Like $(LIB_KIO)). It is recommended to use the macro version if set by the KDE build system.

If a library (A) depends on another library (B), you don't need to specify the dependency library (B). But if you do, (e.g. because the dependencies on A might change), make sure you specify A before B. So usually libtool .la libraries are first, then $(LIB_*), then -lfoo if any.

_LDFLAGS

This defines any flags that need to be passed to the linker. Note that the flags do not get passed to the linker by using _LDADD! These can be -L flags (to change the library search path, usually set by configure into a variable). $(all_libraries) contains all the -L flags necessary to find Qt and KDE, so you must have it there. For programs you should also add $(KDE_RPATH), it helps to get installed programs to find their libraries without having to set LD_LIBRARY_PATH. AM_CPPFLAGS These specify additional compilation flags. This must contain $(all_includes). This is also where other compile-time flags like -DWITHOUTBUGS and -I$(srcdir)/subdir go.

Note: Insert -I directives before $(all_includes). This ensures that your own headers will be used, not some older installed version.

Note that $(srcdir) and . (the build directory) are always included automatically. You may find that Makefile.am files in KDE still use INCLUDES (the old name for AM_CPPFLAGS), but AM_CPPFLAGS is the recommended way to add include paths and other compilation flags.

KDE_CXXFLAGS

There is also KDE_CXXFLAGS. It is always appended to the end of the other flags used in the build, so it can undo one of the flags set by the KDE build framework. This is the case for exception handling support, which is disabled by default. If you want to use exception handling you need to write

KDE_CXXFLAGS = $(USE_EXCEPTIONS)

METASOURCES

METASOURCES = AUTO is the magic line that makes the KDE build system take care of the moc files automatically. It is the recommended way if all your .cpp/.cc files include their .moc file (this is the best way since it gives faster compilation), or if you are compiling a single binary/library.

In case you have multiple binaries/libraries in the same directory, you might need to use the longer form of

libfoo_la_METASOURCES = myfile.moc myotherfile.moc
mybinary_METASOURCES = someotherfile.moc

Makefile.am for shared libraries

Here is an example Makefile.am for a simple library.

AM_CPPFLAGS = $(all_includes)
 
lib_LTLIBRARIES = libkonq.la
 
libkonq_la_LIBADD = $(LIB_KPARTS)
libkonq_la_LDFLAGS = $(all_libraries) -version-info 6:0:2 -no-undefined
libkonq_la_SOURCES = popupmenu.cc knewmenu.cpp ...
 
METASOURCES = AUTO

lib

The lib_ prefix means that the library will be installed in /lib. Then comes the name of the library, always followed by .la (which stands for Libtool archive). Note that this becomes _la in the lines that refer to it.

_LTLIBRARIES

means "LibTool libraries". In other words, it lets the autotools know that libraries should be handled using the libtool program. You should always use this for libraries.

_LIBADD

This is the list of libraries that this library depends on. Note that it is LDADD for programs and LIBADD for libraries, since it's not exactly the same thing. A library only remembers which other libraries it depends on, it doesn't link them into the final library. See LDADD for recommendations about how to order dependencies.

_LDFLAGS

This contains the list of flags passed to the linker. $(all_libraries) is required as usual, but also the version number of the library (see [info:/libtool/Libtool%20versioning info:/libtool/Libtool versioning (Konqueror link only)] for more details). The -no-undefined flag is strongly recommended, as it allows the build system to check at link time that the library has no undefined symbols. If any undefined symbols show up, it means that you either forgot to implement a method, or that a dependant library is missing in the LIBADD line.

The rest of the lines are similar to the compiling a binary case.

Makefile.am for a plugin or module

All dynamically opened pieces of code (including plugins, KParts, kdeinit modules, Kicker applets and KIOSlaves) can be called a "DSO" (Dynamic Shared Object) or more simply for our purposes, a module. All modules should be installed into the "kde_module" directory, which is usually $KDEPREFIX/lib/kde3. Therefore the main difference with a shared library is that one should use

kde_module_LTLIBRARIES = something.la

(Note that the library name doesn't have to start with lib). For more details on the naming conventions and _LDFLAGS necessary for the various types of modules, please read kdelibs/NAMING.

Sharing code with convenience libraries

If you are compiling the same source file with the same option into two shared libraries, or into two programs, which are in the same directory, and using the same compilation options, then that's fine, you can list it in both _SOURCES lines. It will in fact be compiled only once, and the object file will be used by both targets.

However, if you are using the same source file in a library and a program, or if you are sharing it between different directories, then you can't list it in both _SOURCES lines. This is because a library and a program need different compilation options (-fPIC), and in case of different directories, because automake doesn't support source files in other dirs. Instead, you should put the shared source files in either a shared library (installed) or in a convenience library. The latter is a static library (*.a on Unix), which isn't installed as is. The targets (shared libs or programs) that "link" to the convenience library will in fact incorporate the object files from it.

To define a convenience library:

# Just as bin_ means install to /bin and lib_ means
# install to lib/, noinst_ means not to install at all.
noinst_LTLIBRARIES = libcommon.la
libcommon_la_SOURCES = dirk.cpp coolo.cpp ...
 
# no need for LIBADD or LDFLAGS, strictly speaking, but it can help
# if e.g. this code needs $(LIBJPEG), all users of this convenience
# lib won't have to specify it.
 
# Then you can use the convenience lib:
mylib_la_LIBADD = libcommon.la
myprogram_LDADD = libcommon.la

This is also the way that you can compile source files in subdirectories. Automake does not allow

foo_SOURCES = subdir/bar.cc

You have to define a convenience library inside of subdir, and use that from the toplevel directory.

Makefile.am for automated tests

This is an example Makefile.am for an automated test program.

METASOURCES = AUTO
 
check_PROGRAMS = mytestprog.cpp
TESTS = mytestprog
 
mytestprog_SOURCES = mytestprog.cpp
mytestprog_LDFLAGS = $(all_libraries) $(KDE_RPATH)
mytestprog_LDADD = ../libcommon.la
 
AM_CPPFLAGES = -I$(srcdir)/.. $(all_includes)

A common way of adding automated tests to your application is to create a subdirectory called tests. Add tests to the SUBDIRS line in parent Makefile.am and create a Makefile.am in the new tests directory. Use create_makefile (from kdesdk/scripts) to create the new Makefile, and now when you type make check the test program will be compiled (due to check_PROGRAMS) and run (due to TESTS). If the test program returns a non-zero value, make prints out an error message and stops. If the test program shouldn't run automatically (e.g. because it's interactive), omit the TESTS line.

Note that the test program needs to link to a library (either shared or convenience lib) containing the code it's testing. Don't link to a program, KPart, plugin (or other module).

In case your test program needs command-line arguments, use a check-local target to launch it instead of TESTS:

check-local: mytestprog
       ./mytestprog $(srcdir)/datafile

This is Makefile syntax, the second line needs to start with a tab.

Installing data

Header files

To install header files:

include_HEADERS = foo.h bar.h

If the class uses a namespace, e.g. KParts, then the header file should be installed into kparts/foo.h

To do that:

kpartsincludedir = $(includedir)/kparts
kpartsinclude_HEADERS = foo.h bar.h

The first line defines a new directory, the second line installs the files into it. The name before dir and _HEADERS must be the same, but other than that it doesn't matter much what it is.

Data files

To install data files into a standard directory (not a directory path, see below for that), use dirname_DATA.

For instance a Type=Service .desktop file should go into $(kde_servicesdir), therefore you should write:

kde_services_DATA = foo.desktop

To install data files into a custom directory, you must first define it, then you can use it:

myappfoodir = $(kde_datadir)/kmyapp
myappfoo_DATA = bar.desktop

This installs bar.desktop into $KDEPREFIX/share/apps/kmyapp.

For a K Menu entry use:

xdg_apps_DATA = kmyapp.desktop

Icons

To install icons for all KDE applications to use, you can use

KDE_ICON = AUTO

However, if you only need to use icons in one application, you should install the icons into the application's specific directory by doing the following:

appicondir = $(kde_datadir)/myapp/icons
appicon_ICON = AUTO

For AUTO to work (and for the icon loading to work), you need to follow this icon naming convention: themesize-type-name.png (extension can also be .svgz, see below).

Where:

• Theme is hi, lo, or cr for hicolor, locolor, or crystal. The crystal theme is the KDE default, but icons installed there will not be picked up in other desktop environments. Use hicolor for that.
• Size is 16, 22, or 32 for locolor. For hicolor and crystal the size can be 16, 22, 32, 48, 64, or 128, or sc. sc stands for scalable, and the icon should be in SVG format, compressed with GZip, and ending in .svgz instead of .png. The 22x22 size is the default toolbar icon size.
• Type is one of the following:
  • 'app' for an application icon.
  • 'mime' for a mimetype icon.
  • 'action' for a menu item, toolbar button, or other KAction.
  • 'filesys' for a filesystem icon (directories, etc.)
  • 'device' for the cdrom/floppy/hard disk/etc. icons.

You can find the same icon types in the icon chooser dialog as well.

Examples:

   cr32-app-konqueror.png: Application icon.
   cr32-action-insert_frame.png: Toolbar button. Note the use of the underscore, as no hyphen is allowed in the name.
   cr16-action-insert_frame.png: Menu item. 

Note This convention applies to the source files only. Upon installation, the icon will be copied to the right directory, simply named name.png

Uninstalling a .desktop file

If you rename or delete a .desktop file, you might want to "uninstall" the old file, i.e. to overwrite it at install time with a file that says "deleted" in order to provide a smoother migration for people installing from sources.

The first step is to add a file called uninstall.desktop to your sources. It can be shared among subdirectories if needed. It should contain the following lines:

[Desktop Entry]
Encoding=UTF-8
Hidden=true

Now you should edit Makefile.am and add:

install-data-local: uninstall.desktop

$(mkinstalldirs) $(DESTDIR)/$(kde_datadir)/kmyapp $(INSTALL_DATA) $(srcdir)/uninstall.desktop $(DESTDIR) $(kde_datadir)/kmyapp/oldfilename.desktop

where $(kde_datadir)/kmyapp is just an example, it should be replaced with the directory where the .desktop was installed to. Don't forget to prepend $(DESTDIR).

Note The Makefile.am sample is another instance of Makefile formatting, therefore the lines under install-data-local: need to start with tabs

Other types of source files

Qt Designer UI files

To compile Qt Designer UI files, use

foo_SOURCES = mydialog.ui

DCOP stubs and skeletons

To compile a DCOP stub (the client side, calling methods) or skeleton (the "server" side, where the object is implemented), use

foo_SOURCES = client.stub obj.skel

This works if the header file is in the current directory. Otherwise you need to specify where it is, for example:

KDesktopIface_DIR = $(top_srcdir)/kdesktop
foo_SOURCES = KDesktopIface.stub

Generated sources

To generate sources yourself (e.g. with a Perl script), use

generated.cpp $(srcdir)/myscript $(srcdir)/mydata

$(PERL) $(srcdir)/myscript $(srcdir)/mydata -o $@

CLEANFILES = generated.cpp

(Note the Makefile syntax, the second line needs to start with a tab). For generated .cpp files only, this is sufficient, simply add the generated .cpp file to a _SOURCES line. For a generated header file, you might have to ensure that it is compiled first, either with proper dependencies like:

foo.lo: myheader.h

or with

target_COMPILE_FIRST = myheader.h

In case there are a large number of compiled files, you can still use variables, to list them only once in CLEANFILES and target_COMPILE_FIRST, but you still need to write a two-line rule for each file.

Adding subdirectories to the build

In the normal case you need only list the subdirectories to add to the build:

SUBDIRS = foo bar

The current directory "." is implicitly last, so that the current directory compiles after all the subdirectories. To compile some subdirectories after the current directory, insert "." explicitly, like the following:

SUBDIRS = mylib . myplugins

To automatically compile all subdirectories, use

SUBDIRS = $(AUTODIRS)

To compile a subdirectory optionally, you need to use the Automake Conditional feature. The Makefile.am will look like this:

if compile_KOPAINTER
KOPAINTERDIR = kopainter
endif
 
SUBDIRS = foo bar $(KOPAINTERDIR)

The Automake Conditional will be either true or false depending on whether the configure script found whatever feature it was looking for. To use it in the Makefile.am you need to declare it in your configure.in.in file:

AM_CONDITIONAL(compile_KOPAINTER, ...)

The second argument is the test, for instance

test "$foo" = "yes"

Normally you would have run the test in question in the configure.in.in to define the value of foo before setting the AM_CONDITIONAL. An abbreviated example from kdemultimedia/juk:

have_musicbrainz=no
KDE_CHECK_HEADER(tunepimp/tp_c.h, have_musicbrainz=yes)
AM_CONDITIONAL(link_lib_MB, test "x$have_musicbrainz" = xyes)

Toplevel directories

The previous section is only for subdirectories of toplevel directories (toplevel directories are like kdebase/libkonq or kdenetwork/kopete, i.e. a directory below the module). The toplevel directories of a KDE source module are handled in a special way: they are automatically detected, so you don't need a SUBDIRS line there. However you might want to have some control on the ordering, in case of dependencies, so you can write something like this in the Makefile.am.in file for the module:

COMPILE_AFTER_kcontrol = kdm kdesktop
COMPILE_BEFORE_konqueror = libkonq

If you want configure to optionally skip a toplevel directory, use this in the configure.in.in code (in the module):

DO_NOT_COMPILE = "$DO_NOT_COMPILE foobar"

Tip: This is also useful to skip toplevel directories locally at configure time. Simply export DO_NOT_COMPILE with the list of dirs to skip

Documentation

For the language of the documentation:

KDE_LANG = en

If the directories are the application names (e.g. kdebase/doc/kdm will install as "kdm") then you can use the autodetection:

KDE_DOCS = AUTO

You can also force a particular installation directory:

KDE_DOCS = kcontrol/mouse

Translation Support

To make your application translatable, you must use i18n() in the code, around the English strings that appear to the user. You must also define a messages target in your toplevel Makefile.am. A script runs every night, and calls all messages targets as they are, to create the .pot files that end up in the l10n module. Then translators can create .po files that contain the translations of those messages. For applications not in SVN, run

make -f admin/Makefile.common package-messages

to generate the .pot file and

make merge

for the message merge (new .pot file with old .po file).

Note: You need to use a patched gettext program, available from ftp.kde.org for proper support of contextual translations and plural handling.

The messages target in the Makefile.am should simply call xgettext on the sources that contain translatable text. This is not the same as the _SOURCES value, since _SOURCES contains .ui and .skel files that do not work with xgettext. This is why you usually use something like *.cpp *.h instead (make sure to include sub-directories, if any). So in the simple case a messages target will look like:

messages:
       $(XGETTEXT) *.cpp *.h -o $(podir)/mypotfile.pot

Note: Just as with other Makefile rules, the second line must begin with a tab. Also, the name of the .pot file must be unique across KDE, so it is best to use an application name or module name as the prefix, such as kofficefilters.pot.

The file name you use for the .pot file is the name of your main KInstance (for a application, it is the first argument passed to KAboutData, and for components/modules it's the name of the KInstance that you create). If you have .ui (Qt Designer), .rc (XML-GUI) or .kcfg (KConfigXT) files, add

messages: rc.cpp

and the script will create rc.cpp from the ui, rc, and kcfg files in the current directory. If you have .ui, .rc or .kcfg files in subdirectories, you need to add something like

$(EXTRACTRC) */*.rc >> rc.cpp

to the messages target, before the xgettext call (don't forget to start the line with a tab).

Another special case is the "tips" file — an XML file containing tips shown to the user. In this case, use something like

messages:
       perl ./preparetips > tips.cc
       $(XGETTEXT) *.cpp *.h tips.cc -o $(podir)/mypotfile.pit
       rm -f tips.cc

You can find the preparetips script under kdebase/ktip, for instance. The name of the temporary tips.cc file doesn't matter. The last matter is the compilation and installation of .po files. Inside l10n, Makefile.am files contain

KDE_LANG = language

and

POFILES = AUTO

to mean that all the .po files in the directory are installed into that language. If you ship a separate application and you want it to install its own .po files, you'll usually have a po/ subdirectory, and inside the Makefile.am will simply say

POFILES = AUTO

In that case, the .po files are copied depending on their name as $(PACKAGE).mo (for instance, de.po is installed under de/LC_MESSAGES/$(PACKAGE).mo).

Qt only programs

By default the build system assumes you're building a KDE application, so it might do things which require kdecore (e.g. using klocale.h when compiling Qt Designer .ui files). To disable this when building a Qt-only program, use

KDE_OPTIONS = qtonly

Disabling "final" compilation

To prevent the --enable-final configure option from working in a specific directory (for instance, to work on the directory when --enable-final was used for the whole module), you can either use

make no-final ; make no-final-install

or edit the Makefile.am and add

KDE_OPTIONS = nofinal

Things to avoid

Do NOT use the following constructs:

• %.foo: %.bar rules. They are not portable.
• $< in a custom rule. It's not portable. $@ is, however.
• BUILT_SOURCES. Automake doesn't support it properly, it makes $(BUILT_SOURCES) a dependency on Makefile, so e.g. they are regenerated when you call make clean twice.
• Obviously, don't call gcc or ld yourself.

Turning Makefile.am into a Makefile

When you change a Makefile.am, if there is already a Makefile generated from it you can simply run make and the Makefile will automatically be re-generated.

If there is no Makefile created yet, you have two choices.

• Run make -f Makefile.cvs at the toplevel of the module, and re-run configure to regenerate all Makefiles.
• You can also use the create_makefile script (from kdesdk/scripts, installed as part of kdesdk).

To use the create_makefile script, simply type

create_makefile subdir

in the parent directory of subdir. This will create subdir/Makefile from subdir/Makefile.am. There is also a create_makefiles script which works recursively down a directory tree.

Questions?

If you're still stuck, there's several things you can do (THIS IS OUT OF DATE):

• Email the kde-devel mailing list with your question.
• You can use the Discussion tab of this wiki to request clarification of a point.
• Never forget that the source code for KDE is available online. It can be instructive to see how other software projects use Makefile.am.
• You can also ask in the #kde-devel chatroom in irc.kde.org