Convert old-style classes in Scanner/*.py modules to new-style classes.

Ripple effect to fix monkey-patching in test/Scanner/generated.py.

3 files changed, 35 insertions, 20 deletions

diff --git a/src/engine/SCons/Scanner/C.py b/src/engine/SCons/Scanner/C.py
index fd8d2f2..3311a09 100644
--- a/src/engine/SCons/Scanner/C.py
+++ b/src/engine/SCons/Scanner/C.py
@@ -81,7 +81,7 @@ def dictify_CPPDEFINES(env):
         return {cppdefines : None}
     return cppdefines
 
-class SConsCPPScannerWrapper:
+class SConsCPPScannerWrapper(object):
     """
     The SCons wrapper around a cpp.py scanner.
 
diff --git a/src/engine/SCons/Scanner/__init__.py b/src/engine/SCons/Scanner/__init__.py
index dcee1f1..562a361 100644
--- a/src/engine/SCons/Scanner/__init__.py
+++ b/src/engine/SCons/Scanner/__init__.py
@@ -35,7 +35,7 @@ import SCons.Node.FS
 import SCons.Util
 
 
-class _Null:
+class _Null(object):
     pass
 
 # This is used instead of None as a default argument value so None can be
@@ -61,7 +61,7 @@ def Scanner(function, *args, **kw):
 
 
 
-class FindPathDirs:
+class FindPathDirs(object):
     """A class to bind a specific *PATH variable name to a function that
     will return all of the *path directories."""
     def __init__(self, variable):
@@ -79,7 +79,7 @@ class FindPathDirs:
 
 
 
-class Base:
+class Base(object):
     """
     The base class for dependency scanners.  This implements
     straightforward, single-pass scanning of a single file.
diff --git a/test/Scanner/generated.py b/test/Scanner/generated.py
index 0212043..8b08732 100644
--- a/test/Scanner/generated.py
+++ b/test/Scanner/generated.py
@@ -307,22 +307,37 @@ def write_out(file, dict):
         f.write(file + ": " + str(dict[k]) + "\\n")
     f.close()
 
-orig_function = CScan.__call__
-
-def MyCScan(node, paths, cwd, orig_function=orig_function):
-    deps = orig_function(node, paths, cwd)
-
-    global Scanned
-    n = str(node)
-    try:
-        Scanned[n] = Scanned[n] + 1
-    except KeyError:
-        Scanned[n] = 1
-    write_out(r'%s', Scanned)
-
-    return deps
-
-CScan.__call__ = MyCScan
+# A hand-coded new-style class proxy to wrap the underlying C Scanner
+# with a method that counts the calls.
+#
+# This is more complicated than it used to be with old-style classes
+# because the .__*__() methods in new-style classes are not looked
+# up on the instance, but resolve to the actual wrapped class methods,
+# so we have to handle those directly.
+class CScannerCounter(object):
+    def __init__(self, original_CScanner, *args, **kw):
+        self.original_CScanner = original_CScanner
+    def __cmp__(self, *args, **kw):
+        return self.original_CScanner.__cmp__(*args, **kw)
+    def __hash__(self, *args, **kw):
+        return self.original_CScanner.__hash__(*args, **kw)
+    def __str__(self, *args, **kw):
+        return self.original_CScanner.__str__(*args, **kw)
+    def __getattr__(self, *args, **kw):
+        return self.original_CScanner.__getattribute__(*args, **kw)
+    def __call__(self, node, *args, **kw):
+        global Scanned
+        n = str(node)
+        try:
+            Scanned[n] = Scanned[n] + 1
+        except KeyError:
+            Scanned[n] = 1
+        write_out(r'%s', Scanned)
+        return self.original_CScanner(node, *args, **kw)
+
+import SCons.Tool
+MyCScanner = CScannerCounter(SCons.Script.CScanner)
+SCons.Tool.SourceFileScanner.add_scanner('.c', MyCScanner)
 
 env = Environment(CPPPATH = ".")
 l = env.StaticLibrary("g", Split("libg_1.c libg_2.c libg_3.c"))