Merge pull request #288 from matrix-org/markjh/unused_definitions

Remove some of the unused definitions from synapse

1 files changed, 142 insertions, 0 deletions

diff --git a/scripts-dev/definitions.py b/scripts-dev/definitions.py
new file mode 100755
index 0000000000..f0d0cd8a3f
--- /dev/null
+++ b/scripts-dev/definitions.py
@@ -0,0 +1,142 @@
+#! /usr/bin/python
+
+import ast
+import yaml
+
+class DefinitionVisitor(ast.NodeVisitor):
+    def __init__(self):
+        super(DefinitionVisitor, self).__init__()
+        self.functions = {}
+        self.classes = {}
+        self.names = {}
+        self.attrs = set()
+        self.definitions = {
+            'def': self.functions,
+            'class': self.classes,
+            'names': self.names,
+            'attrs': self.attrs,
+        }
+
+    def visit_Name(self, node):
+        self.names.setdefault(type(node.ctx).__name__, set()).add(node.id)
+
+    def visit_Attribute(self, node):
+        self.attrs.add(node.attr)
+        for child in ast.iter_child_nodes(node):
+            self.visit(child)
+
+    def visit_ClassDef(self, node):
+        visitor = DefinitionVisitor()
+        self.classes[node.name] = visitor.definitions
+        for child in ast.iter_child_nodes(node):
+            visitor.visit(child)
+
+    def visit_FunctionDef(self, node):
+        visitor = DefinitionVisitor()
+        self.functions[node.name] = visitor.definitions
+        for child in ast.iter_child_nodes(node):
+            visitor.visit(child)
+
+
+def non_empty(defs):
+    functions = {name: non_empty(f) for name, f in defs['def'].items()}
+    classes = {name: non_empty(f) for name, f in defs['class'].items()}
+    result = {}
+    if functions: result['def'] = functions
+    if classes: result['class'] = classes
+    names = defs['names']
+    uses = []
+    for name in names.get('Load', ()):
+        if name not in names.get('Param', ()) and name not in names.get('Store', ()):
+            uses.append(name)
+    uses.extend(defs['attrs'])
+    if uses: result['uses'] = uses
+    result['names'] = names
+    result['attrs'] = defs['attrs']
+    return result
+
+
+def definitions_in_code(input_code):
+    input_ast = ast.parse(input_code)
+    visitor = DefinitionVisitor()
+    visitor.visit(input_ast)
+    definitions = non_empty(visitor.definitions)
+    return definitions
+
+
+def definitions_in_file(filepath):
+    with open(filepath) as f:
+        return definitions_in_code(f.read())
+
+
+def defined_names(prefix, defs, names):
+    for name, funcs in defs.get('def', {}).items():
+        names.setdefault(name, {'defined': []})['defined'].append(prefix + name)
+        defined_names(prefix + name + ".", funcs, names)
+
+    for name, funcs in defs.get('class', {}).items():
+        names.setdefault(name, {'defined': []})['defined'].append(prefix + name)
+        defined_names(prefix + name + ".", funcs, names)
+
+
+def used_names(prefix, defs, names):
+    for name, funcs in defs.get('def', {}).items():
+        used_names(prefix + name + ".", funcs, names)
+
+    for name, funcs in defs.get('class', {}).items():
+        used_names(prefix + name + ".", funcs, names)
+
+    for used in defs.get('uses', ()):
+        if used in names:
+            names[used].setdefault('used', []).append(prefix.rstrip('.'))
+
+
+if __name__ == '__main__':
+    import sys, os, argparse, re
+
+    parser = argparse.ArgumentParser(description='Find definitions.')
+    parser.add_argument(
+        "--unused", action="store_true", help="Only list unused definitions"
+    )
+    parser.add_argument(
+        "--ignore", action="append", metavar="REGEXP", help="Ignore a pattern"
+    )
+    parser.add_argument(
+        "--pattern", action="append", metavar="REGEXP",
+        help="Search for a pattern"
+    )
+    parser.add_argument(
+        "directories", nargs='+', metavar="DIR",
+        help="Directories to search for definitions"
+    )
+    args = parser.parse_args()
+
+    definitions = {}
+    for directory in args.directories:
+        for root, dirs, files in os.walk(directory):
+            for filename in files:
+                if filename.endswith(".py"):
+                    filepath = os.path.join(root, filename)
+                    definitions[filepath] = definitions_in_file(filepath)
+
+    names = {}
+    for filepath, defs in definitions.items():
+        defined_names(filepath + ":", defs, names)
+
+    for filepath, defs in definitions.items():
+        used_names(filepath + ":", defs, names)
+
+    patterns = [re.compile(pattern) for pattern in args.pattern or ()]
+    ignore = [re.compile(pattern) for pattern in args.ignore or ()]
+
+    result = {}
+    for name, definition in names.items():
+        if patterns and not any(pattern.match(name) for pattern in patterns):
+            continue
+        if ignore and any(pattern.match(name) for pattern in ignore):
+            continue
+        if args.unused and definition.get('used'):
+            continue
+        result[name] = definition
+
+    yaml.dump(result, sys.stdout, default_flow_style=False)