setup: when possible, build and bundle man pages

setup: when possible, build and bundle man pages

This makes it so the manual pages are built as part of the Python
build, and includes them in any wheel generated. This should make
Python wheels a much more useful and complete way of distributing
Mercurial binaries.

Differential Revision: https://phab.mercurial-scm.org/D9640

--- a/setup.py	Tue Dec 08 16:41:13 2020 +0530
+++ b/setup.py	Mon Dec 21 15:50:01 2020 +0100
@@ -196,6 +196,7 @@
 from distutils.command.build_py import build_py
 from distutils.command.build_scripts import build_scripts
 from distutils.command.install import install
+from distutils.command.install_data import install_data
 from distutils.command.install_lib import install_lib
 from distutils.command.install_scripts import install_scripts
 from distutils import log
@@ -212,6 +213,12 @@
 # Explain to distutils.StrictVersion how our release candidates are versionned
 StrictVersion.version_re = re.compile(r'^(\d+)\.(\d+)(\.(\d+))?-?(rc(\d+))?$')
 
+# Can we build the documentation?
+try:
+    import docutils
+except ImportError:
+    docutils = None
+
 
 def write_if_changed(path, content):
     """Write content to a file iff the content hasn't changed."""
@@ -471,6 +478,14 @@
     # when build_py is run next.
     sub_commands = [('build_mo', None)] + build.sub_commands
 
+    def run(self):
+        if os.name == 'nt':
+            pass
+        elif docutils is None:
+            log.warn('not building optional documentation')
+        else:
+            self.run_command('build_doc')
+
 
 class hgbuildmo(build):
 
@@ -1040,6 +1055,43 @@
                 genhtml(root)
 
 
+class hginstalldata(install_data):
+    user_options = install_data.user_options + [
+        (
+            'install-man=',
+            None,
+            'installation directory for manual pages [share/man]',
+        ),
+    ]
+
+    install_man = None
+
+    def finalize_options(self):
+        install_data.finalize_options(self)
+
+        self.set_undefined_options('install', ('install_man', 'install_man'))
+
+        if self.install_man is None:
+            self.install_man = os.path.join('share', 'man')
+
+        if os.name == 'nt':
+            pass
+        elif docutils is None:
+            log.warn('not installing manual pages')
+        else:
+            manpages = [
+                f for f in os.listdir('doc') if re.search(r'\.[0-9]$', f)
+            ]
+
+            self.data_files += [
+                (
+                    os.path.join(self.install_man, 'man' + ext[1:]),
+                    ['doc/' + f for f in manpages if f.endswith(ext)],
+                )
+                for ext in set(os.path.splitext(f)[1] for f in manpages)
+            ]
+
+
 class hginstall(install):
 
     user_options = install.user_options + [
@@ -1053,17 +1105,26 @@
             None,
             'noop, present for eggless setuptools compat',
         ),
+        (
+            'install-man=',
+            None,
+            'installation directory for manual pages [share/man]',
+        ),
     ]
 
     # Also helps setuptools not be sad while we refuse to create eggs.
     single_version_externally_managed = True
 
+    install_man = None
+
     def get_sub_commands(self):
+        subcommands = install.get_sub_commands(self)
+        subcommands.append('install_data')
         # Screen out egg related commands to prevent egg generation.  But allow
         # mercurial.egg-info generation, since that is part of modern
         # packaging.
         excl = {'bdist_egg'}
-        return filter(lambda x: x not in excl, install.get_sub_commands(self))
+        return filter(lambda x: x not in excl, subcommands)
 
 
 class hginstalllib(install_lib):
@@ -1265,6 +1326,7 @@
     'build_hgextindex': buildhgextindex,
     'install': hginstall,
     'install_lib': hginstalllib,
+    'install_data': hginstalldata,
     'install_scripts': hginstallscripts,
     'build_hgexe': buildhgexe,
 }