Merge pull request #94 from jayvdb/setup-compile-fallback-v040

Issue #26 Use pure python on compilation failure

.travis.yml

@@ -12,3 +12,8 @@ script:
     - coverage run --source=mwparserfromhell setup.py -q test
 after_success:
     - coveralls
+
+env:
+  matrix:
+    - WITHOUT_EXTENSION=0
+    - WITHOUT_EXTENSION=1

setup.py

@@ -21,12 +21,16 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 
+import os
 import sys
 
 if (sys.version_info[0] == 2 and sys.version_info[1] < 6) or \
    (sys.version_info[1] == 3 and sys.version_info[1] < 2):
     raise Exception("mwparserfromhell needs Python 2.6+ or 3.2+")
 
+if sys.version_info >= (3, 0):
+    basestring = (str, )
+
 from setuptools import setup, find_packages, Extension
 
 from mwparserfromhell import __version__
@@ -39,7 +43,63 @@ tokenizer = Extension("mwparserfromhell.parser._tokenizer",
                       sources=["mwparserfromhell/parser/tokenizer.c"],
                       depends=["mwparserfromhell/parser/tokenizer.h"])
 
-setup(
+use_extension=True
+
+# Allow env var WITHOUT_EXTENSION and args --with[out]-extension
+if '--without-extension' in sys.argv:
+    use_extension = False
+elif '--with-extension' in sys.argv:
+    pass
+elif os.environ.get('WITHOUT_EXTENSION', '0') == '1':
+    use_extension = False
+
+# Remove the command line argument as it isnt understood by
+# setuptools/distutils
+sys.argv = [arg for arg in sys.argv
+            if not arg.startswith('--with')
+            and not arg.endswith('-extension')]
+
+
+def optional_compile_setup(func=setup, use_ext=use_extension,
+                           *args, **kwargs):
+    """
+    Wrap setup to allow optional compilation of extensions.
+
+    Falls back to pure python mode (no extensions)
+    if compilation of extensions fails.
+    """
+    extensions = kwargs.get('ext_modules', None)
+
+    if use_ext and extensions:
+        try:
+            func(*args, **kwargs)
+            return
+        except SystemExit as e:
+            assert(e.args)
+            if e.args[0] is False:
+                raise
+            elif isinstance(e.args[0], basestring):
+                if e.args[0].startswith('usage: '):
+                    raise
+                else:
+                    # Fallback to pure python mode
+                    print('setup with extension failed: %s' % repr(e))
+                    pass
+        except Exception as e:
+            print('setup with extension failed: %s' % repr(e))
+
+    if extensions:
+        if use_ext:
+            print('Falling back to pure python mode.')
+        else:
+            print('Using pure python mode.')
+
+        del kwargs['ext_modules']
+
+    func(*args, **kwargs)
+
+
+optional_compile_setup(
     name = "mwparserfromhell",
     packages = find_packages(exclude=("tests",)),
     ext_modules = [tokenizer],