[PATCH 0 of 2] setup: don't build inotify extension when <sys/inotify.h> is too old

[Christian Boos]

On 6/17/2010 3:58 AM, Renato Cunha wrote:
> Hello,
>
> On Wed, Jun 16, 2010 at 14:30,<cboos at neuf.fr>  wrote:
>> This is admittedly because of my too old sys/inotify.h header,
>> or some other brokenness on my system, but as I don't want to use
>> the inotify extension anyway, I'd prefer to simply avoid building
>> inotify when it's anyway going to fail.
>>
>> To that end, I added an "hasflags" function, which reuses the
>> "hasfunction" code.
>
> The idea is interesting, as inotify is not a mercurial requirement.
> But wouldn't it be better if, instead of checking for arbitrary flags
> in some include files, it was possible for the build process to go on
> when non-core stuff failed building?

Thanks for the suggestion!

Here's a new patch, which ignore failures to build extensions marked as 
optional (so only inotify currently), in the same way distutils does it 
in Python 3.

Here's the code for build_ext.build_extensions() in Python 2.x:

     def build_extensions(self):
         # First, sanity-check the 'extensions' list
         self.check_extensions_list(self.extensions)

         for ext in self.extensions:
             self.build_extension(ext)

Here's the corresponding method in Python 3.x versions:

     def build_extensions(self):
         # First, sanity-check the 'extensions' list
         self.check_extensions_list(self.extensions)

         for ext in self.extensions:
             try:
                 self.build_extension(ext)
             except (CCompilerError, DistutilsError, CompileError) as e:
                 if not ext.optional:
                     raise
                 self.warn('building extension "%s" failed: %s' %
                           (ext.name, e))

So I added something similar in setup.py.


# HG changeset patch
# User Christian Boos <cboos at neuf.fr>
# Date 1277106460 -7200
# Node ID ce6870449d03a18471aa145ae8065bf09942420a
# Parent  6f1d1ed3e19aaf4bfc14741956e0e6ff06fbe9d2
setup: ignore failure to build optional inotify extension

diff -r 6f1d1ed3e19a -r ce6870449d03 setup.py
--- a/setup.py    Sun Jun 20 14:21:56 2010 -0500
+++ b/setup.py    Mon Jun 21 09:47:40 2010 +0200
@@ -38,9 +38,11 @@
  from distutils.core import setup, Extension
  from distutils.dist import Distribution
  from distutils.command.build import build
+from distutils.command.build_ext import build_ext
  from distutils.command.build_py import build_py
  from distutils.spawn import spawn, find_executable
  from distutils.ccompiler import new_compiler
+from distutils.errors import CCompilerError

  scripts = ['hg']
  if os.name == 'nt':
@@ -209,6 +211,20 @@
  Distribution.global_options.append(('pure', None, "use pure (slow) 
Python "
                                      "code instead of C extensions"))

+class hgbuildext(build_ext):
+
+    def build_extensions(self):
+        # First, sanity-check the 'extensions' list
+        self.check_extensions_list(self.extensions)
+
+        for ext in self.extensions:
+            try:
+                self.build_extension(ext)
+            except CCompilerError:
+                if not hasattr(ext, 'optional') or not ext.optional:
+                    raise
+                print>>sys.stderr, "Skipping optional '%s'" % ext.name
+
  class hgbuildpy(build_py):

      def finalize_options(self):
@@ -232,6 +248,7 @@
                  yield module

  cmdclass = {'build_mo': hgbuildmo,
+            'build_ext': hgbuildext,
              'build_py': hgbuildpy}

  packages = ['mercurial', 'mercurial.hgweb', 'hgext', 'hgext.convert',
@@ -260,6 +277,7 @@
      if hasfunction(cc, 'inotify_add_watch'):
          extmodules.append(Extension('hgext.inotify.linux._inotify',
                                       ['hgext/inotify/linux/_inotify.c']))
+        extmodules[-1].optional = True
          packages.extend(['hgext.inotify', 'hgext.inotify.linux'])

  packagedata = {'mercurial': ['locale/*/LC_MESSAGES/hg.mo',