Set module metadata for site_scons/site_init.py files. From Arve Knudsen; closes issue 2520.

3 files changed, 70 insertions, 6 deletions

diff --git a/src/CHANGES.txt b/src/CHANGES.txt
index c63f206..a9d4372 100644
--- a/src/CHANGES.txt
+++ b/src/CHANGES.txt
@@ -7,6 +7,12 @@
 
 RELEASE 2.1.0.alpha.yyyymmdd - NEW DATE WILL BE INSERTED HERE
 
+  From Arve Knudsen:
+
+    - Set module metadata when loading site_scons/site_init.py
+      so it is treated as a proper module; __doc__, __file__ and
+      __name__ now refer to the site_init.py file.
+
   From Russel Winder:
 
     - Users Guide updates explaining that Tools can be packages as
diff --git a/src/engine/SCons/Script/Main.py b/src/engine/SCons/Script/Main.py
index eed782e..b4ebb09 100644
--- a/src/engine/SCons/Script/Main.py
+++ b/src/engine/SCons/Script/Main.py
@@ -688,7 +688,7 @@ def _load_site_scons_dir(topdir, site_dir_name=None):
     site_init_file = os.path.join(site_dir, site_init_filename)
     site_tools_dir = os.path.join(site_dir, site_tools_dirname)
     if os.path.exists(site_init_file):
-        import imp
+        import imp, re
         # TODO(2.4): turn this into try:-except:-finally:
         try:
             try:
@@ -707,14 +707,26 @@ def _load_site_scons_dir(topdir, site_dir_name=None):
                     fmt = 'cannot import site_init.py: missing SCons.Script module %s'
                     raise SCons.Errors.InternalError(fmt % repr(e))
                 try:
+                    sfx = description[0]
+                    modname = os.path.basename(pathname)[:-len(sfx)]
+                    site_m = {"__file__": pathname, "__name__": modname, "__doc__": None}
+                    re_special = re.compile("__[^_]+__")
+                    for k in m.__dict__.keys():
+                        if not re_special.match(k):
+                            site_m[k] = m.__dict__[k]
+
                     # This is the magic.
-                    exec fp in m.__dict__
+                    exec fp in site_m
                 except KeyboardInterrupt:
                     raise
                 except Exception, e:
                     fmt = '*** Error loading site_init file %s:\n'
                     sys.stderr.write(fmt % repr(site_init_file))
                     raise
+                else:
+                    for k in site_m:
+                        if not re_special.match(k):
+                            m.__dict__[k] = site_m[k]
             except KeyboardInterrupt:
                 raise
             except ImportError, e:
diff --git a/test/site_scons/site_init.py b/test/site_scons/site_init.py
index 83c9a7f..9f2e411 100644
--- a/test/site_scons/site_init.py
+++ b/test/site_scons/site_init.py
@@ -24,18 +24,64 @@
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
+"""
+Verify various aspects of the handling of site_init.py.
+
+And more ..
+"""
+
 import TestSCons
 import sys
+import os.path
+
+test = TestSCons.TestSCons()
+
+test.subdir('site_scons')
+
+
+def _test_metadata():
+    """Test site_init's module metadata.
+    
+    The following special variables should be predefined: __doc__,
+    __file__ and __name__. No special variables should be transferred from
+    SCons.Script.
+    """
+    test.write(['site_scons', 'site_init.py'], """\
+import os.path
+import re
+
+special = []
+for x in globals().keys():
+    if re.match("__[^_]+__", x):
+        if x in ("__builtins__", "__package__",):
+            # Ignore certain keywords, as they are known to be added by Python
+            continue
+        special.append(x)
+
+print sorted(special)
+print __doc__
+print os.path.realpath(__file__)
+print __name__
+""")
+
+    test.write('SConstruct', "\n")
+    test.run(arguments = '-Q .',
+             stdout = """\
+['__doc__', '__file__', '__name__']
+None
+%s
+site_init
+scons: `.' is up to date.
+""" % (os.path.realpath(os.path.join('site_scons', 'site_init.py')),))
+
+_test_metadata()
+
 
 """
 Verify site_scons/site_init.py file can define a tool, and it shows up
 automatically in the SCons.Script namespace.
 """
 
-test = TestSCons.TestSCons()
-
-test.subdir('site_scons')
-
 if sys.platform == 'win32':
     cat_cmd='type'
 else: