setup.py: ./configure and make libevent if libevent sources are found. link...

setup.py: ./configure and make libevent if libevent sources are found. link gevent/core.so statically against libevent.
If a directory "libevent-src" is found, we use that as default to the
--libevent argument.

If the --libevent directory does not contain a .libs directory (that
is if make hasn't been run), setup.py will now run configure and make
in order to link statically against libevent.

It also contains some workarounds to correctly build on OS X:
  - it does build a "fat" gevent.core
  - it adapts linker flags and uses the statically linked libevent
    even if a dynamic one is on the search path

setup.py

@@ -60,6 +60,8 @@ class my_build_ext(build_ext.build_ext):
             sys.exit(1)
 
     def build_extension(self, ext):
+        compile_libevent(self)
+
         self.compile_cython()
         result = build_ext.build_ext.build_extension(self, ext)
         # hack: create a symlink from build/../core.so to gevent/core.so
@@ -89,6 +91,72 @@ class my_build_ext(build_ext.build_ext):
             traceback.print_exc()
         return result
 
+cmdclass = {'build_ext': my_build_ext}
+
+
+def mysystem(cmd):
+    err = os.system(cmd)
+    if err:
+        sys.exit("running %r failed" % cmd)
+
+
+def compile_libevent(build):
+    sdir = libevent_source_path
+    if not sdir:
+        return
+
+    from distutils import sysconfig
+
+    configure = os.path.abspath(os.path.join(sdir, "configure"))
+    addlibs = []
+    bdir = os.path.join(build.build_temp, "libevent")
+    if not os.path.isdir(bdir):
+        os.makedirs(bdir)
+
+    cwd = os.getcwd()
+    os.chdir(bdir)
+    try:
+        if "CC" not in os.environ:
+            cc = sysconfig.get_config_var("CC")
+            if cc:
+                os.environ["CC"] = cc
+
+            archflags = sysconfig.get_config_var("ARCHFLAGS")
+            if archflags:
+                os.environ["AM_CFLAGS"] = archflags
+
+        if not exists("./config.status"):
+            mysystem("%s --with-pic --disable-shared --disable-dependency-tracking" % configure)
+        mysystem("make")
+
+        for line in open("Makefile"):
+            if line.startswith("LIBS = "):
+                addlibs = [x[2:] for x in line[len("LIBS = "):].strip().split() if x.startswith("-l")]
+    finally:
+        os.chdir(cwd)
+
+    if build is None:
+        return
+
+    if build.include_dirs is None:
+        build.include_dirs = []
+    if build.library_dirs is None:
+        build.library_dirs = []
+    # bdir is needed for event-config.h
+    build.include_dirs[:0] = [bdir, sdir, "%s/include" % sdir]
+    build.library_dirs[:0] = ["%s/.libs" % bdir]
+    build.libraries.extend(addlibs)
+
+    cc = build.compiler
+    if sys.platform == "darwin":
+        # stupid apple: http://developer.apple.com/mac/library/qa/qa2006/qa1393.html
+        cc.linker_so += ['-Wl,-search_paths_first']
+        cc.linker_exe += ['-Wl,-search_paths_first']
+
+    cc.set_include_dirs(build.include_dirs)
+    cc.set_library_dirs(build.library_dirs)
+    cc.set_libraries(build.libraries)
+
 
 def check_dir(path, must_exist):
     if not isdir(path):
@@ -109,6 +177,18 @@ def add_library_dir(path, must_exist=True):
         library_dirs.append(path)
 
 
+def enable_libevent_source_path():
+    add_include_dir(join(libevent_source_path, 'include'), must_exist=False)
+    add_include_dir(libevent_source_path, must_exist=False)
+    add_library_dir(join(libevent_source_path, '.libs'), must_exist=False)
+    if sys.platform == 'win32':
+        add_include_dir(join(libevent_source_path, 'compat'), must_exist=False)
+        add_include_dir(join(libevent_source_path, 'WIN32-Code'), must_exist=False)
+
+    global compile_libevent
+    compile_libevent = lambda *a: None
+
+
 # parse options: -I NAME / -INAME / -L NAME / -LNAME / --libevent DIR
 # we're cutting out options from sys.path instead of using optparse
 # so that these option can co-exists with distutils' options
@@ -128,17 +208,14 @@ while i < len(sys.argv):
     elif arg == '--libevent':
         del sys.argv[i]
         libevent_source_path = sys.argv[i]
-        add_include_dir(join(libevent_source_path, 'include'), must_exist=False)
-        add_include_dir(libevent_source_path, must_exist=False)
-        add_library_dir(join(libevent_source_path, '.libs'), must_exist=False)
-        if sys.platform == 'win32':
-            add_include_dir(join(libevent_source_path, 'compat'), must_exist=False)
-            add_include_dir(join(libevent_source_path, 'WIN32-Code'), must_exist=False)
     else:
         i += 1
         continue
     del sys.argv[i]
 
+if libevent_source_path is None and os.path.isdir("libevent-src"):
+    libevent_source_path = "libevent-src"
+    print "using libevent sources in libevent-src"
 
 # sources used when building on windows; this includes sources of both libevent-1.4
 # and libevent-2 combined, but will filter out the files that do not exist
@@ -176,8 +253,8 @@ else:
     if sys.platform == 'win32':
         if not libevent_source_path:
             sys.exit('Please provide path to libevent source with --libevent DIR')
-        extra_compile_args += ['-DHAVE_CONFIG_H']
-        extra_compile_args += ['-DWIN32']
+        enable_libevent_source_path()
+        extra_compile_args += ['-DHAVE_CONFIG_H', '-DWIN32']
         libraries = ['wsock32', 'advapi32', 'ws2_32', 'shell32']
         include_dirs.extend([join(libevent_source_path, 'WIN32-Code'),
                              join(libevent_source_path, 'compat')])
@@ -189,7 +266,8 @@ else:
             sources.append(filename)
     else:
         libraries = ['event']
-
+        if libevent_source_path and os.path.exists(os.path.join(libevent_source_path, ".libs")):
+            enable_libevent_source_path()
 
 gevent_core = Extension(name='gevent.core',
                         sources=sources,