Bug 1259960 - s/DummyFunction/DependsFunction/. r=chmanchester

While DummyFunction is descriptive of what the instances are (and they
can't even be called), the various uses of isintance(obj, DummyFunction)
are kind of confusing, especially when they are in moz.configure land
(and this bug is about to add another one).

build/moz.configure/init.configure

@@ -132,8 +132,8 @@ def extra_old_configure_args(help):
 @template
 @advanced
 def add_old_configure_assignment(var, value_func):
-    from mozbuild.configure import DummyFunction
-    assert isinstance(value_func, DummyFunction)
+    from mozbuild.configure import DependsFunction
+    assert isinstance(value_func, DependsFunction)
 
     @depends(old_configure_assignments, value_func)
     @advanced

python/mozbuild/mozbuild/configure/__init__.py

@@ -37,7 +37,7 @@ class ConfigureError(Exception):
     pass
 
 
-class DummyFunction(object):
+class DependsFunction(object):
     '''Sandbox-visible representation of @depends functions.'''
     def __call__(self, *arg, **kwargs):
         raise RuntimeError('The `%s` function may not be called'
@@ -104,7 +104,7 @@ class ConfigureSandbox(dict):
         self._paths = []
         self._templates = set()
         # Store the real function and its dependencies, behind each
-        # DummyFunction generated from @depends.
+        # DependsFunction generated from @depends.
         self._depends = {}
         self._seen = set()
 
@@ -231,7 +231,7 @@ class ConfigureSandbox(dict):
                 hasattr(self, '%s_impl' % key)):
             raise KeyError('Cannot reassign builtins')
 
-        if (not isinstance(value, DummyFunction) and
+        if (not isinstance(value, DependsFunction) and
                 value not in self._templates and
                 not issubclass(value, Exception)):
             raise KeyError('Cannot assign `%s` because it is neither a '
@@ -240,7 +240,7 @@ class ConfigureSandbox(dict):
         return super(ConfigureSandbox, self).__setitem__(key, value)
 
     def _resolve(self, arg, need_help_dependency=True):
-        if isinstance(arg, DummyFunction):
+        if isinstance(arg, DependsFunction):
             assert arg in self._depends
             func, deps = self._depends[arg]
             assert not inspect.isgeneratorfunction(func)
@@ -328,7 +328,7 @@ class ConfigureSandbox(dict):
                 dependencies.append(arg)
                 assert arg in self._option_values or self._help
                 resolved_arg = self._option_values.get(arg)
-            elif isinstance(arg, DummyFunction):
+            elif isinstance(arg, DependsFunction):
                 assert arg in self._depends
                 dependencies.append(arg)
                 arg, _ = self._depends[arg]
@@ -345,12 +345,12 @@ class ConfigureSandbox(dict):
                 raise ConfigureError(
                     'Cannot decorate generator functions with @depends')
             func, glob = self._prepare_function(func)
-            dummy = wraps(func)(DummyFunction())
+            dummy = wraps(func)(DependsFunction())
             self._depends[dummy] = func, dependencies
             with_help = self._help_option in dependencies
             if with_help:
                 for arg in args:
-                    if isinstance(arg, DummyFunction):
+                    if isinstance(arg, DependsFunction):
                         _, deps = self._depends[arg]
                         if self._help_option not in deps:
                             raise ConfigureError(
@@ -488,7 +488,7 @@ class ConfigureSandbox(dict):
         # Don't do anything when --help was on the command line
         if self._help:
             return
-        if not reason and isinstance(value, DummyFunction):
+        if not reason and isinstance(value, DependsFunction):
             deps = self._depends[value][1]
             possible_reasons = [d for d in deps if d != self._help_option]
             if len(possible_reasons) == 1:
@@ -496,7 +496,7 @@ class ConfigureSandbox(dict):
                     reason = (self._raw_options.get(possible_reasons[0]) or
                               possible_reasons[0].option)
 
-        if not reason or not isinstance(value, DummyFunction):
+        if not reason or not isinstance(value, DependsFunction):
             raise ConfigureError(
                 "Cannot infer what implies '%s'. Please add a `reason` to "
                 "the `imply_option` call."