PYTHONPATH : python patches methods for its extensions

7 files changed, 53 insertions, 27 deletions

diff --git a/lib/spack/spack/build_environment.py b/lib/spack/spack/build_environment.py
index 68477145fe..c51fa58477 100644
--- a/lib/spack/spack/build_environment.py
+++ b/lib/spack/spack/build_environment.py
@@ -282,9 +282,11 @@ def setup_package(pkg):
     for mod in modules:
         set_module_variables_for_package(pkg, mod)
 
-    # Allow dependencies to set up environment as well.
+    # Allow dependencies to modify the module
     for dependency_spec in pkg.spec.traverse(root=False):
         dependency_spec.package.modify_module(pkg.module, dependency_spec, pkg.spec)
+    # Allow dependencies to set up environment as well
+    for dependency_spec in pkg.spec.traverse(root=False):
         dependency_spec.package.setup_dependent_environment(env, pkg.spec)
     # TODO : implement validation
     #validate(env)
diff --git a/lib/spack/spack/cmd/uninstall.py b/lib/spack/spack/cmd/uninstall.py
index d01aa2136b..2fab8f6f2a 100644
--- a/lib/spack/spack/cmd/uninstall.py
+++ b/lib/spack/spack/cmd/uninstall.py
@@ -79,7 +79,7 @@ def uninstall(parser, args):
                 try:
                     # should work if package is known to spack
                     pkgs.append(s.package)
-                except spack.repository.UnknownPackageError, e:
+                except spack.repository.UnknownPackageError as e:
                     # The package.py file has gone away -- but still
                     # want to uninstall.
                     spack.Package(s).do_uninstall(force=True)
@@ -94,11 +94,11 @@ def uninstall(parser, args):
         for pkg in pkgs:
             try:
                 pkg.do_uninstall(force=args.force)
-            except PackageStillNeededError, e:
+            except PackageStillNeededError as e:
                 tty.error("Will not uninstall %s" % e.spec.format("$_$@$%@$#", color=True))
-                print
-                print "The following packages depend on it:"
+                print()
+                print("The following packages depend on it:")
                 display_specs(e.dependents, long=True)
-                print
-                print "You can use spack uninstall -f to force this action."
+                print()
+                print("You can use spack uninstall -f to force this action.")
                 sys.exit(1)
diff --git a/lib/spack/spack/directory_layout.py b/lib/spack/spack/directory_layout.py
index 39ee4e203d..da8f1aa1bc 100644
--- a/lib/spack/spack/directory_layout.py
+++ b/lib/spack/spack/directory_layout.py
@@ -150,7 +150,7 @@ class DirectoryLayout(object):
         if os.path.exists(path):
             try:
                 shutil.rmtree(path)
-            except exceptions.OSError, e:
+            except exceptions.OSError as e:
                 raise RemoveFailedError(spec, path, e)
 
         path = os.path.dirname(path)
diff --git a/lib/spack/spack/modules.py b/lib/spack/spack/modules.py
index d192bbe004..7303844229 100644
--- a/lib/spack/spack/modules.py
+++ b/lib/spack/spack/modules.py
@@ -119,13 +119,13 @@ class EnvModule(object):
                 module_types[cls.name] = cls
 
     def __init__(self, spec=None):
+        self.spec = spec
+        self.pkg = spec.package  # Just stored for convenience
+
         # category in the modules system
         # TODO: come up with smarter category names.
         self.category = "spack"
 
-        self.spec = spec
-        self.pkg = spec.package  # Just stored for convenience
-
         # short description default is just the package + version
         # packages can provide this optional attribute
         self.short_description = spec.format("$_ $@")
@@ -161,6 +161,12 @@ class EnvModule(object):
 
         # Environment modifications guessed by inspecting the installation prefix
         env = inspect_path(self.spec.prefix)
+
+        # Let the extendee modify their extensions before asking for package-specific modifications
+        for extendee in self.pkg.extendees:
+            extendee_spec = self.spec[extendee]
+            extendee_spec.package.modify_module(self.pkg, extendee_spec, self.spec)
+
         # Package-specific environment modifications
         self.spec.package.setup_environment(env)
         # TODO : implement site-specific modifications and filters
diff --git a/lib/spack/spack/package.py b/lib/spack/spack/package.py
index 185e3ad2ee..72c84ec624 100644
--- a/lib/spack/spack/package.py
+++ b/lib/spack/spack/package.py
@@ -1261,16 +1261,6 @@ class Package(object):
         """Get the rpath args as a string, with -Wl,-rpath, for each element."""
         return " ".join("-Wl,-rpath,%s" % p for p in self.rpath)
 
-
-class PythonExtension(Package):
-    def setup_dependent_environment(self, env, dependent_spec):
-        pass
-
-    def setup_environment(self, env):
-        site_packages = glob.glob(join_path(self.spec.prefix.lib, "python*/site-packages"))
-        if site_packages:
-            env.prepend_path('PYTHONPATH', site_packages[0])
-
 def validate_package_url(url_string):
     """Determine whether spack can handle a particular URL or not."""
     url = urlparse(url_string)
diff --git a/var/spack/repos/builtin/packages/py-nose/package.py b/var/spack/repos/builtin/packages/py-nose/package.py
index e817b8eb51..4fee99098e 100644
--- a/var/spack/repos/builtin/packages/py-nose/package.py
+++ b/var/spack/repos/builtin/packages/py-nose/package.py
@@ -1,12 +1,12 @@
 from spack import *
-from spack.package import PythonExtension
 
-class PyNose(PythonExtension):
+
+class PyNose(Package):
     """nose extends the test loading and running features of unittest,
     making it easier to write, find and run tests."""
 
     homepage = "https://pypi.python.org/pypi/nose"
-    url      = "https://pypi.python.org/packages/source/n/nose/nose-1.3.4.tar.gz"
+    url = "https://pypi.python.org/packages/source/n/nose/nose-1.3.4.tar.gz"
 
     version('1.3.4', '6ed7169887580ddc9a8e16048d38274d')
     version('1.3.6', '0ca546d81ca8309080fc80cb389e7a16')
diff --git a/var/spack/repos/builtin/packages/python/package.py b/var/spack/repos/builtin/packages/python/package.py
index d46e1068b6..c445d26369 100644
--- a/var/spack/repos/builtin/packages/python/package.py
+++ b/var/spack/repos/builtin/packages/python/package.py
@@ -1,11 +1,14 @@
+import functools
+import glob
+import inspect
 import os
 import re
 from contextlib import closing
-from llnl.util.lang import match_predicate
-from spack.util.environment import *
 
-from spack import *
 import spack
+from llnl.util.lang import match_predicate
+from spack import *
+from spack.util.environment import *
 
 
 class Python(Package):
@@ -111,6 +114,31 @@ class Python(Package):
         else:
             module.python = Executable(join_path(spec.prefix.bin, 'python'))
 
+        # The code below patches the any python extension to have good defaults for `setup_dependent_environment` and
+        # `setup_environment` only if the extension didn't override any of these functions explicitly.
+        def _setup_env(self, env):
+            site_packages = glob.glob(join_path(self.spec.prefix.lib, "python*/site-packages"))
+            if site_packages:
+                env.prepend_path('PYTHONPATH', site_packages[0])
+
+        def _setup_denv(self, env, extension_spec):
+            pass
+
+        pkg_cls = type(ext_spec.package)  # Retrieve the type we may want to patch
+        if 'python' in pkg_cls.extendees:
+            # List of overrides we are interested in
+            interesting_overrides = ['setup_environment', 'setup_dependent_environment']
+            overrides_found = [
+                (name, defining_cls) for name, _, defining_cls, _, in inspect.classify_class_attrs(pkg_cls)
+                if
+                name in interesting_overrides and  # The attribute has the right name
+                issubclass(defining_cls, Package) and defining_cls is not Package  # and is an actual override
+            ]
+            if not overrides_found:
+                # If no override were found go on patching
+                pkg_cls.setup_environment = functools.wraps(Package.setup_environment)(_setup_env)
+                pkg_cls.setup_dependent_environment = functools.wraps(Package.setup_dependent_environment)(_setup_denv)
+
         # Add variables for lib/pythonX.Y and lib/pythonX.Y/site-packages dirs.
         module.python_lib_dir     = os.path.join(ext_spec.prefix, self.python_lib_dir)
         module.python_include_dir = os.path.join(ext_spec.prefix, self.python_include_dir)