Expose a way for distributors to override default directories
This allows placing a `distro_directories.py` file in the meson
module which exports a `default_directories` dict to override
all of the defaults similar to config.site in autoconf.
Fixes #2557
diff --git a/docs/markdown/Distributors.md b/docs/markdown/Distributors.md
new file mode 100644
index 0000000..2966abe
--- /dev/null
+++ b/docs/markdown/Distributors.md
@@ -0,0 +1,85 @@
+---
+title: Distributors
+short-description: Guide for distributors using meson
+...
+
+# Using Meson
+
+Distro packagers usually want total control on the build flags
+used. Meson supports this use case natively. The commands needed to
+build and install Meson projects are the following.
+
+```console
+$ cd /path/to/source/root
+$ CFLAGS=... CXXFLAGS=... LDFLAGS=.. meson --prefix /usr --buildtype=plain builddir
+$ ninja -v -C builddir
+$ ninja -C builddir test
+$ DESTDIR=/path/to/staging/root ninja -C builddir install
+```
+
+The command line switch `--buildtype=plain` tells Meson not to add its
+own flags to the command line. This gives the packager total control
+on used flags.
+
+This is very similar to other build systems. The only difference is
+that the `DESTDIR` variable is passed as an environment variable
+rather than as an argument to `ninja install`.
+
+As distro builds happen always from scratch, we recommend you to
+enable [unity builds](Unity-builds.md) whenever possible on your
+packages because they are faster and produce better code.
+
+## Overriding Default Directories
+
+Many distributions differ in their directory layout so as of Meson 0.45.0 we expose
+an easy method of overriding the default behavior. The reason you would want to
+override these is *not* for packages it is for users building software on the distro
+as they expect `meson` without any specified arguments to go into the right location.
+In build scripts for packages it should explicitly set any directories especially `prefix`.
+
+Inside the `mesonbuild` python module you can create a `distro_directories.py` file
+and `meson` will import the `default_directories` dictionary from that and
+override the internal defaults. As such it can do any arbitrary task such as
+checking the architecture at runtime.
+
+The list of these directories as well as their descriptions and defaults can be found
+in `meson --help` or alternatively in `default_directories` in `mesonlib.py`.
+
+Some simple examples:
+
+```python
+default_directories = {
+ 'libdir': 'lib', # Avoid the lib64 heuristics in meson
+ 'libexecdir': 'lib', # Some distros don't have a dedicated libexec
+}
+```
+
+```python
+import platform
+
+if platform.machine() in ('x86_64', 'aarch64'):
+ libdir = 'lib64'
+else:
+ libdir = 'lib'
+
+
+default_directories = {
+ 'libdir': libdir,
+}
+```
+
+```python
+import subprocess
+
+pc = subprocess.Popen(['dpkg-architecture', '-qDEB_HOST_MULTIARCH'],
+ stdout=subprocess.PIPE,
+ stderr=subprocess.DEVNULL)
+(stdo, _) = pc.communicate()
+assert pc.returncode == 0
+archpath = stdo.decode().strip()
+libdir = 'lib/' + archpath
+
+default_directories = {
+ 'libdir': libdir,
+}
+```
\ No newline at end of file
diff --git a/docs/markdown/Quick-guide.md b/docs/markdown/Quick-guide.md
index 938c3ed..0d46dc0 100644
--- a/docs/markdown/Quick-guide.md
+++ b/docs/markdown/Quick-guide.md
@@ -76,26 +76,4 @@
Using Meson as a distro packager
--
-Distro packagers usually want total control on the build flags
-used. Meson supports this use case natively. The commands needed to
-build and install Meson projects are the following.
-
-```console
-$ cd /path/to/source/root
-$ CFLAGS=... CXXFLAGS=... LDFLAGS=.. meson --prefix /usr --buildtype=plain builddir
-$ ninja -v -C builddir
-$ ninja -C builddir test
-$ DESTDIR=/path/to/staging/root ninja -C builddir install
-```
-
-The command line switch `--buildtype=plain` tells Meson not to add its
-own flags to the command line. This gives the packager total control
-on used flags.
-
-This is very similar to other build systems. The only difference is
-that the `DESTDIR` variable is passed as an environment variable
-rather than as an argument to `ninja install`.
-
-As distro builds happen always from scratch, we recommend you to
-enable [unity builds](Unity-builds.md) whenever possible on your
-packages because they are faster and produce better code.
+See [the distributors page](Distributors.md) for more information.
diff --git a/docs/markdown/Release-notes-for-0.45.0.md b/docs/markdown/Release-notes-for-0.45.0.md
index b3df71c..96a66c7 100644
--- a/docs/markdown/Release-notes-for-0.45.0.md
+++ b/docs/markdown/Release-notes-for-0.45.0.md
@@ -5,12 +5,7 @@
# New features
-This page is a placeholder for the eventual release notes.
+## Added ability for distributors to easily override default directories
-Notable new features should come with release note updates. This is
-done by creating a file snippet called `snippets/featurename.md` and
-whose contents should look like this:
-
- ## Feature name
-
- A short description explaining the new feature and how it should be used.
+Distributors can now install a `distro_directories.py` file to override
+the Meson defaults. See [the distributors page](Distributors.md) for more details.
diff --git a/mesonbuild/coredata.py b/mesonbuild/coredata.py
index 0fdac8b..44ea83f 100644
--- a/mesonbuild/coredata.py
+++ b/mesonbuild/coredata.py
@@ -19,7 +19,7 @@
from pathlib import PurePath
from collections import OrderedDict
from .mesonlib import MesonException
-from .mesonlib import default_libdir, default_libexecdir, default_prefix
+from .mesonlib import default_directories
import ast
version = '0.45.0.dev1'
@@ -392,19 +392,19 @@
'buildtype': [UserComboOption, 'Build type to use.', ['plain', 'debug', 'debugoptimized', 'release', 'minsize'], 'debug'],
'strip': [UserBooleanOption, 'Strip targets on install.', False],
'unity': [UserComboOption, 'Unity build.', ['on', 'off', 'subprojects'], 'off'],
- 'prefix': [UserStringOption, 'Installation prefix.', default_prefix()],
- 'libdir': [UserStringOption, 'Library directory.', default_libdir()],
- 'libexecdir': [UserStringOption, 'Library executable directory.', default_libexecdir()],
- 'bindir': [UserStringOption, 'Executable directory.', 'bin'],
- 'sbindir': [UserStringOption, 'System executable directory.', 'sbin'],
- 'includedir': [UserStringOption, 'Header file directory.', 'include'],
- 'datadir': [UserStringOption, 'Data file directory.', 'share'],
- 'mandir': [UserStringOption, 'Manual page directory.', 'share/man'],
- 'infodir': [UserStringOption, 'Info page directory.', 'share/info'],
- 'localedir': [UserStringOption, 'Locale data directory.', 'share/locale'],
- 'sysconfdir': [UserStringOption, 'Sysconf data directory.', 'etc'],
- 'localstatedir': [UserStringOption, 'Localstate data directory.', 'var'],
- 'sharedstatedir': [UserStringOption, 'Architecture-independent data directory.', 'com'],
+ 'prefix': [UserStringOption, 'Installation prefix.', default_directories['prefix']],
+ 'libdir': [UserStringOption, 'Library directory.', default_directories['libdir']],
+ 'libexecdir': [UserStringOption, 'Library executable directory.', default_directories['libexecdir']],
+ 'bindir': [UserStringOption, 'Executable directory.', default_directories['bindir']],
+ 'sbindir': [UserStringOption, 'System executable directory.', default_directories['sbindir']],
+ 'includedir': [UserStringOption, 'Header file directory.', default_directories['includedir']],
+ 'datadir': [UserStringOption, 'Data file directory.', default_directories['datadir']],
+ 'mandir': [UserStringOption, 'Manual page directory.', default_directories['mandir']],
+ 'infodir': [UserStringOption, 'Info page directory.', default_directories['infodir']],
+ 'localedir': [UserStringOption, 'Locale data directory.', default_directories['localedir']],
+ 'sysconfdir': [UserStringOption, 'Sysconf data directory.', default_directories['sysconfdir']],
+ 'localstatedir': [UserStringOption, 'Localstate data directory.', default_directories['localstatedir']],
+ 'sharedstatedir': [UserStringOption, 'Architecture-independent data directory.', default_directories['sharedstatedir']],
'werror': [UserBooleanOption, 'Treat warnings as errors.', False],
'warning_level': [UserComboOption, 'Compiler warning level to use.', ['1', '2', '3'], '1'],
'layout': [UserComboOption, 'Build directory layout.', ['mirror', 'flat'], 'mirror'],
diff --git a/mesonbuild/dependencies/misc.py b/mesonbuild/dependencies/misc.py
index 9614f1f..05adf52 100644
--- a/mesonbuild/dependencies/misc.py
+++ b/mesonbuild/dependencies/misc.py
@@ -390,7 +390,7 @@
if self.libdir:
libdirs = [self.libdir]
elif self.boost_root is None:
- libdirs = mesonlib.get_library_dirs()
+ libdirs = mesonlib.default_directories['librarydirs']
else:
libdirs = [os.path.join(self.boost_root, 'lib')]
for libdir in libdirs:
diff --git a/mesonbuild/mesonlib.py b/mesonbuild/mesonlib.py
index 4871bf7..9d71c7e 100644
--- a/mesonbuild/mesonlib.py
+++ b/mesonbuild/mesonlib.py
@@ -449,7 +449,8 @@
found.append(req)
return not_found == [], not_found, found
-def default_libdir():
+
+def _default_libdir():
if is_debianlike():
try:
pc = subprocess.Popen(['dpkg-architecture', '-qDEB_HOST_MULTIARCH'],
@@ -465,14 +466,8 @@
return 'lib64'
return 'lib'
-def default_libexecdir():
- # There is no way to auto-detect this, so it must be set at build time
- return 'libexec'
-def default_prefix():
- return 'c:/' if is_windows() else '/usr/local'
-
-def get_library_dirs():
+def _default_library_dirs():
if is_windows():
return ['C:/mingw/lib'] # Fixme
if is_osx():
@@ -500,6 +495,33 @@
return unixdirs
+# These are mostly documented in builtin_options in coredata.py
+default_directories = {
+ 'prefix': 'c:/' if is_windows() else '/usr/local',
+ 'bindir': 'bin',
+ 'sbindir': 'sbin',
+ 'libdir': _default_libdir(),
+ 'libexecdir': 'libexec',
+ 'datadir': 'share',
+ 'includedir': 'include',
+ 'mandir': 'share/man',
+ 'infodir': 'share/info',
+ 'localedir': 'share/locale',
+ 'sysconfdir': 'etc',
+ 'localstatedir': 'var',
+ 'sharedstatedir': 'com',
+ 'librarydirs': _default_library_dirs(),
+}
+
+
+try:
+ # Allow distros to insert a file that sets its own directories
+ from .distro_directories import default_directories as overrides
+ default_directories.update(overrides)
+except ImportError:
+ pass
+
+
def do_replacement(regex, line, confdata):
missing_variables = set()
