├── demo.gif ├── examples ├── .DS_Store ├── complex_structure.py ├── ambiguous_types.py └── arithmetics.py ├── requirements.txt ├── gct ├── constants.py ├── __init__.py ├── __main__.py ├── url.py ├── syntax_tree.py ├── package_config.py ├── parse.py ├── network.py ├── api.py ├── type_check.py └── utils.py ├── pyproject.toml ├── .gitignore ├── README.md └── LICENSE /demo.gif: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/QasimWani/gct/HEAD/demo.gif -------------------------------------------------------------------------------- /examples/.DS_Store: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/QasimWani/gct/HEAD/examples/.DS_Store -------------------------------------------------------------------------------- /requirements.txt: -------------------------------------------------------------------------------- 1 | argparse==1.4.0 2 | graphviz==0.20.1 3 | networkx==2.8.8 4 | platform==1.0.8 -------------------------------------------------------------------------------- /gct/constants.py: -------------------------------------------------------------------------------- 1 | ROOT_NODE = -1 2 | ROOT_NODE_LINENO = -1 3 | NODE_NAMES_TO_IGNORE = {"super"} 4 | SELF_NODE_NAME = "self" 5 | TEMP_FOLDER = "temp" 6 | GRAPH_FOLDER_DEFAULT_NAME = "gct_graph" 7 | -------------------------------------------------------------------------------- /gct/__init__.py: -------------------------------------------------------------------------------- 1 | """Top-level package for GCT.""" 2 | # gct/__init__.py 3 | 4 | __app_name__ = "gct" 5 | __version__ = "0.1.6" 6 | 7 | ( 8 | SUCCESS, 9 | DIR_ERROR, 10 | FILE_ERROR, 11 | DB_READ_ERROR, 12 | DB_WRITE_ERROR, 13 | JSON_ERROR, 14 | ID_ERROR, 15 | ) = range(7) 16 | 17 | ERRORS = { 18 | DIR_ERROR: "config directory error", 19 | FILE_ERROR: "config file error", 20 | DB_READ_ERROR: "database read error", 21 | DB_WRITE_ERROR: "database write error", 22 | ID_ERROR: "to-do id error", 23 | } 24 | 25 | 26 | # Make sure that all python packages are installed 27 | from .package_config import installer 28 | 29 | installer() 30 | -------------------------------------------------------------------------------- /examples/complex_structure.py: -------------------------------------------------------------------------------- 1 | class A: 2 | def a(): 3 | pass 4 | 5 | class B: 6 | def b(): 7 | pass 8 | 9 | class C: 10 | def c(): 11 | pass 12 | 13 | class D: 14 | def d(): 15 | pass 16 | 17 | 18 | class E: 19 | def e(): 20 | pass 21 | 22 | 23 | class F: 24 | def f(): 25 | pass 26 | 27 | 28 | class G: 29 | def h(): 30 | pass 31 | 32 | def i(): 33 | pass 34 | 35 | def j(): 36 | pass 37 | 38 | class K: 39 | def l(): 40 | pass 41 | 42 | def m(): 43 | pass 44 | 45 | def n(): 46 | pass 47 | -------------------------------------------------------------------------------- /pyproject.toml: -------------------------------------------------------------------------------- 1 | [build-system] 2 | requires = [ 3 | "setuptools>=61.0", 4 | "argparse==1.4.0", 5 | "graphviz==0.20.1", 6 | "networkx", 7 | "requests" 8 | ] 9 | 10 | build-backend = "setuptools.build_meta" 11 | 12 | [project] 13 | name = "gct-py" 14 | version = "0.1.6" 15 | authors = [ 16 | { name="Qasim Wani", email="qasim@vt.edu" }, 17 | ] 18 | description = "Visualize Python code at lightning speed" 19 | readme = "README.md" 20 | requires-python = ">=3.7" 21 | classifiers = [ 22 | "Programming Language :: Python :: 3", 23 | "License :: OSI Approved :: GNU General Public License v3 (GPLv3)", 24 | "Operating System :: OS Independent", 25 | ] 26 | [tool.poetry.scripts] 27 | gct = "gct.__main__:main" 28 | 29 | [project.urls] 30 | "Homepage" = "https://gctpy.com" 31 | "Bug Tracker" = "https://github.com/QasimWani/gct/issues" 32 | -------------------------------------------------------------------------------- /examples/ambiguous_types.py: -------------------------------------------------------------------------------- 1 | class Preferences: 2 | def __init__(self) -> None: 3 | super().__init__() 4 | 5 | def func(self): 6 | pass 7 | 8 | def preferences(self): 9 | pass 10 | 11 | 12 | class Utility: 13 | def __init__(self) -> None: 14 | pass 15 | 16 | def func(self): 17 | pass 18 | 19 | def utility(self): 20 | pass 21 | 22 | 23 | class Meta: 24 | def __init__(self) -> None: 25 | pass 26 | 27 | def func(self): 28 | pass 29 | 30 | def meta(self): 31 | pass 32 | 33 | 34 | def func(): 35 | pass 36 | 37 | 38 | # def call_preferences_and_utility(): 39 | # preferences = Preferences() 40 | # utility = Utility() 41 | # preferences.func() 42 | # utility.func() 43 | 44 | 45 | def call_preferences_and_meta(): 46 | preferences = Preferences() 47 | meta = Meta() 48 | preferences.func() 49 | meta.func() 50 | 51 | 52 | def call_utility(): 53 | utility = Utility() 54 | utility.func() 55 | 56 | 57 | def call_all_functions(): 58 | Preferences.func() 59 | Utility.func() 60 | Meta.func() 61 | func() 62 | -------------------------------------------------------------------------------- /gct/__main__.py: -------------------------------------------------------------------------------- 1 | """ 2 | Wrapper around api.py to run GCT on any file/URL. 3 | """ 4 | import sys 5 | 6 | sys.path.append("../gct") 7 | 8 | import gct.api as api 9 | from gct.url import fetch_valid_url 10 | import argparse 11 | from gct.constants import TEMP_FOLDER, GRAPH_FOLDER_DEFAULT_NAME 12 | from gct import __version__ 13 | 14 | parser = argparse.ArgumentParser() 15 | parser.add_argument( 16 | "--input", 17 | "-i", 18 | type=str, 19 | required=True, 20 | help="File path or URL to visualize", 21 | ) 22 | 23 | parser.add_argument( 24 | "--destination_folder", 25 | "-d", 26 | type=str, 27 | default=f"{TEMP_FOLDER}", 28 | help="Folder path to save resulting GCT graph to", 29 | ) 30 | 31 | parser.add_argument( 32 | "--version", 33 | "-v", 34 | action="version", 35 | version=f"GCT version: {__version__}", 36 | ) 37 | 38 | 39 | def main(): 40 | args = parser.parse_args() 41 | 42 | # Download file if URL is valid 43 | status = fetch_valid_url(args.input) 44 | path = status["url"] 45 | if not status["valid"]: 46 | path = args.input 47 | 48 | graph, _ = api.run(path) 49 | 50 | api.render( 51 | graph, 52 | file_path=f"{args.destination_folder}/{GRAPH_FOLDER_DEFAULT_NAME}", 53 | output_format="pdf", 54 | ) 55 | 56 | 57 | if __name__ == "__main__": 58 | main() 59 | -------------------------------------------------------------------------------- /gct/url.py: -------------------------------------------------------------------------------- 1 | """ Ported from gct-server """ 2 | import urllib.request 3 | 4 | 5 | def fetch_valid_url(url: str): 6 | """Make sure valid URL. Parses github URLs to raw githubusercontent URLs.""" 7 | status = {"valid": False, "url": None} 8 | if url is None or len(url.strip()) == 0 or not url.startswith("http"): 9 | return status 10 | 11 | # Handle github raw URL. 12 | host = urllib.request.urlparse(url).hostname 13 | if host.startswith("raw.githubusercontent.com"): 14 | # Try to open the URL. 15 | status["valid"] = try_open_url(url) 16 | status["url"] = url 17 | return status 18 | if host.startswith("github.com"): 19 | # Try to open the URL. 20 | is_valid = try_open_url(url) 21 | if not is_valid: 22 | status["url"] = url 23 | return status 24 | # Convert to raw githubusercontent URL. 25 | url = url.replace("github.com", "raw.githubusercontent.com") 26 | url = url.replace("/blob/", "/") 27 | status["valid"] = try_open_url(url) 28 | status["url"] = url 29 | return status 30 | else: 31 | status["valid"] = try_open_url(url) 32 | status["url"] = url 33 | return status 34 | 35 | 36 | def try_open_url(url: str): 37 | try: 38 | urllib.request.urlopen(url) 39 | return True 40 | except Exception as e: 41 | print(e) 42 | return False 43 | -------------------------------------------------------------------------------- /gct/syntax_tree.py: -------------------------------------------------------------------------------- 1 | import ast 2 | from gct.network import Node 3 | from collections import deque 4 | 5 | 6 | class FunctionCallVisitor(ast.NodeVisitor): 7 | """Extract all function calls""" 8 | 9 | def __init__(self): 10 | self._name = deque() 11 | 12 | @property 13 | def name(self): 14 | # return self._name[-1] 15 | return ".".join(self._name) 16 | 17 | @name.deleter 18 | def name(self): 19 | self._name.clear() 20 | 21 | def visit_Name(self, node): 22 | self._name.appendleft(node.id) 23 | 24 | def visit_Attribute(self, node): 25 | try: 26 | self._name.appendleft(node.attr) 27 | self._name.appendleft(node.value.id) 28 | except AttributeError: 29 | self.generic_visit(node) 30 | 31 | 32 | class UserDefinedFuncVisitor(ast.NodeVisitor): 33 | """Extract all user defined functions and classes""" 34 | 35 | def __init__(self): 36 | self.node: Node = None 37 | 38 | def create_node(self, node: ast.AST, node_name: str, type: str): 39 | end_lineno = node.lineno - 1 if "end_lineno" in dir(node) else str(None) 40 | self.node = Node(node.lineno - 1, end_lineno, node_name, type) 41 | 42 | def visit_Lambda(self, node: ast.Lambda): 43 | raise NotImplementedError("Lambda functions are not supported yet") 44 | self.create_node(node, "lambda", "function") 45 | 46 | def visit_FunctionDef(self, node: ast.FunctionDef): 47 | self.create_node(node, node.name, "function") 48 | 49 | def visit_AsyncFunctionDef(self, node: ast.AsyncFunctionDef): 50 | self.create_node(node, node.name, "function") 51 | 52 | def visit_ClassDef(self, node: ast.ClassDef): 53 | self.create_node(node, node.name, "class") 54 | -------------------------------------------------------------------------------- /gct/package_config.py: -------------------------------------------------------------------------------- 1 | import platform 2 | import subprocess 3 | 4 | GRAPHVIZ_INSTRUCTIONS_LINK = "https://github.com/QasimWani/gct/blob/main/README.md#step-2-skip-if-already-installed-install-graphviz-executable" 5 | GCT_ISSUE_LINK = "https://github.com/QasimWani/gct/issues/new" 6 | 7 | 8 | def _install_pip_package(package: str): 9 | try: 10 | __import__(package) 11 | except ImportError: 12 | subprocess.check_call(["pip", "install", package]) 13 | 14 | 15 | def _is_graphviz_installed(): 16 | """Function that checks if graphviz is installed""" 17 | try: 18 | subprocess.Popen(["dot", "-V"], stdout=subprocess.PIPE, stderr=subprocess.PIPE) 19 | return True 20 | except Exception as e: 21 | print("Graphviz not installed. See instructions for graphviz:", e) 22 | return False 23 | 24 | 25 | def _is_dot_installed(): 26 | if _is_graphviz_installed(): 27 | return 28 | 29 | system = platform.system() 30 | if system == "Windows": 31 | message = "Graphviz package not install. Try running 'choco install -y graphviz'. \n If the error persists, install graphviz from here: https://graphviz.org/download" 32 | elif system == "Darwin": # macOS 33 | message = "Graphviz package not install. Try running 'brew install graphviz'. \n If the error persists, install graphviz from here: https://graphviz.org/download" 34 | else: # assume Linux or other Unix-like system 35 | message = "Graphviz package not install. Try running 'apt-get install graphviz'. \n If the error persists, install graphviz from here: https://graphviz.org/download" 36 | 37 | message += f"\nFor any other errors, please post an issue (response time <= 10 minutes): {GCT_ISSUE_LINK}" 38 | raise Exception(message) 39 | 40 | 41 | # Install python packages and graphviz dist. if they don't exist. 42 | def installer(): 43 | PACKAGES = ["argparse", "graphviz", "networkx", "platform", "requests"] 44 | for package in PACKAGES: 45 | _install_pip_package(package) 46 | 47 | _is_dot_installed() 48 | -------------------------------------------------------------------------------- /examples/arithmetics.py: -------------------------------------------------------------------------------- 1 | from typing import Union 2 | 3 | # define a new type `ArithmeticInput` that can be either int or float 4 | # Note: you can't do: type('ArithmeticInput', (int, float), {}) 5 | # because you're int and float have a common base class which creates lay-out conflict. 6 | ArithmeticInput = Union[int, float] 7 | 8 | 9 | class Math: 10 | """Simple class that defines basic numerical operations""" 11 | 12 | def __init__(self) -> None: 13 | self._buffer = [] 14 | 15 | @property 16 | def buffer(self): 17 | return self._buffer 18 | 19 | def _add_output_to_buffer(self, result: ArithmeticInput): 20 | self.buffer.append(result) 21 | 22 | def add(self, op1: ArithmeticInput, op2: ArithmeticInput): 23 | ans = op1 + op2 24 | self._add_output_to_buffer(ans) 25 | return ans 26 | 27 | def sub(self, op1: ArithmeticInput, op2: ArithmeticInput): 28 | ans = op1 - op2 29 | self._add_output_to_buffer(ans) 30 | return ans 31 | 32 | def mul(self, op1: ArithmeticInput, op2: ArithmeticInput): 33 | ans = op1 * op2 34 | self._add_output_to_buffer(ans) 35 | return ans 36 | 37 | def div(self, op1: ArithmeticInput, op2: ArithmeticInput): 38 | def is_division_by_zero(num): 39 | if num == 0: 40 | return True 41 | 42 | if is_division_by_zero(op2): 43 | return float("inf") 44 | 45 | ans = op1 / op2 46 | self._add_output_to_buffer(ans) 47 | return ans 48 | 49 | def output_basic_operations(self, op1: ArithmeticInput, op2: ArithmeticInput): 50 | assert isinstance(op1, (int, float)), "`op1` Must be either int or float" 51 | assert isinstance(op2, (int, float)), "`op2` Must be either int or float" 52 | self.add(op1, op2) 53 | self.sub(op1, op2) 54 | self.mul(op1, op2) 55 | self.div(op1, op2) 56 | 57 | 58 | if __name__ == "__main__": 59 | math = Math() 60 | op1, op2 = 10, 5 61 | math.output_basic_operations(op1, op2) 62 | memory = math.buffer 63 | print(memory) 64 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | # Byte-compiled / optimized / DLL files 2 | __pycache__/ 3 | *.py[cod] 4 | *$py.class 5 | 6 | # C extensions 7 | *.so 8 | 9 | # Distribution / packaging 10 | .Python 11 | build/ 12 | develop-eggs/ 13 | dist/ 14 | downloads/ 15 | eggs/ 16 | .eggs/ 17 | lib/ 18 | lib64/ 19 | parts/ 20 | sdist/ 21 | var/ 22 | wheels/ 23 | pip-wheel-metadata/ 24 | share/python-wheels/ 25 | *.egg-info/ 26 | .installed.cfg 27 | *.egg 28 | MANIFEST 29 | 30 | # PyInstaller 31 | # Usually these files are written by a python script from a template 32 | # before PyInstaller builds the exe, so as to inject date/other infos into it. 33 | *.manifest 34 | *.spec 35 | 36 | # Installer logs 37 | pip-log.txt 38 | pip-delete-this-directory.txt 39 | 40 | # Unit test / coverage reports 41 | htmlcov/ 42 | .tox/ 43 | .nox/ 44 | .coverage 45 | .coverage.* 46 | .cache 47 | nosetests.xml 48 | coverage.xml 49 | *.cover 50 | *.py,cover 51 | .hypothesis/ 52 | .pytest_cache/ 53 | 54 | # Translations 55 | *.mo 56 | *.pot 57 | 58 | # Django stuff: 59 | *.log 60 | local_settings.py 61 | db.sqlite3 62 | db.sqlite3-journal 63 | 64 | # Flask stuff: 65 | instance/ 66 | .webassets-cache 67 | 68 | # Scrapy stuff: 69 | .scrapy 70 | 71 | # Sphinx documentation 72 | docs/_build/ 73 | 74 | # PyBuilder 75 | target/ 76 | 77 | # Jupyter Notebook 78 | .ipynb_checkpoints 79 | 80 | # IPython 81 | profile_default/ 82 | ipython_config.py 83 | 84 | # pyenv 85 | .python-version 86 | 87 | # pipenv 88 | # According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control. 89 | # However, in case of collaboration, if having platform-specific dependencies or dependencies 90 | # having no cross-platform support, pipenv may install dependencies that don't work, or not 91 | # install all needed dependencies. 92 | #Pipfile.lock 93 | 94 | # PEP 582; used by e.g. github.com/David-OConnor/pyflow 95 | __pypackages__/ 96 | 97 | # Celery stuff 98 | celerybeat-schedule 99 | celerybeat.pid 100 | 101 | # SageMath parsed files 102 | *.sage.py 103 | 104 | # Environments 105 | .env 106 | .venv 107 | env/ 108 | venv/ 109 | ENV/ 110 | env.bak/ 111 | venv.bak/ 112 | 113 | # Spyder project settings 114 | .spyderproject 115 | .spyproject 116 | 117 | # Rope project settings 118 | .ropeproject 119 | 120 | # mkdocs documentation 121 | /site 122 | 123 | # mypy 124 | .mypy_cache/ 125 | .dmypy.json 126 | dmypy.json 127 | 128 | # Pyre type checker 129 | .pyre/ 130 | 131 | # Ignore temp folder 132 | temp/ 133 | 134 | # Ignore .vscode 135 | .vscode/ -------------------------------------------------------------------------------- /gct/parse.py: -------------------------------------------------------------------------------- 1 | import ast 2 | import gct.utils as utils 3 | from gct.syntax_tree import FunctionCallVisitor, UserDefinedFuncVisitor 4 | from gct.network import Node, Graph 5 | import gct.constants as constants 6 | from gct.type_check import Metadata 7 | 8 | 9 | def extract(tree: ast, raw_code: "list[str]"): 10 | """2 pass algorithm""" 11 | 12 | node_line_map: "dict[int, Node]" = { 13 | constants.ROOT_NODE: Node(constants.ROOT_NODE_LINENO, len(raw_code), "root") 14 | } 15 | node_creation_graph = Graph() 16 | edge_creation_graph = Graph() 17 | 18 | # Node creation 19 | for node in ast.walk(tree): 20 | if isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef, ast.ClassDef)): 21 | func_visitor = UserDefinedFuncVisitor() 22 | func_visitor.visit(node) 23 | node_line_map[func_visitor.node.line_start] = func_visitor.node 24 | 25 | # Node connection 26 | for start_lineno, node in node_line_map.items(): 27 | node: Node = node 28 | if ( 29 | start_lineno == constants.ROOT_NODE_LINENO 30 | ): # root node has no parent. skip connection 31 | continue 32 | parent_lineno: int = utils.get_immediate_parent(raw_code, start_lineno) 33 | parent_node: Node = node_line_map[parent_lineno] 34 | 35 | node_creation_graph.add_edge(parent_node, node) 36 | # Edge connection 37 | for node in ast.walk(tree): 38 | if isinstance(node, ast.Call): 39 | call_visitor = FunctionCallVisitor() 40 | call_visitor.visit(node.func) 41 | 42 | # 1. find immediate parent (i.e. scope of where this function was called) 43 | # 2. find what function is being called (i.e. scope of where this function was defined) 44 | # 3. connect (1) to (2) via `Edge` 45 | 46 | line_start_source_function = utils.get_immediate_parent( 47 | raw_code, node.lineno - 1, call_visitor.name 48 | ) 49 | 50 | source_node: Node = None 51 | 52 | if line_start_source_function in node_line_map: 53 | source_node = node_line_map[line_start_source_function] 54 | else: 55 | continue # skip if source function is not defined in the file 56 | 57 | potential_target_nodes = utils.find_function_of_interest( 58 | call_visitor.name, 59 | Metadata( 60 | tree, 61 | raw_code, 62 | node_creation_graph, 63 | node_line_map, 64 | line_start_source_function, 65 | ), 66 | ) 67 | 68 | # ignore all root connections for now 69 | if source_node.line_start == constants.ROOT_NODE_LINENO: 70 | continue 71 | 72 | # create an edge for each potential target node with source node 73 | for target_node in potential_target_nodes: 74 | edge_creation_graph.add_edge(source_node, target_node) 75 | 76 | return node_creation_graph, edge_creation_graph 77 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | 2 | 3 |
4 | 5 | # Graphical Code Tracer 6 |

7 | 8 | users 9 | 10 | 11 | license 12 | 13 | 14 | license 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 |

23 | 24 | Graphical Code Tracer (gct) is the world's first visual static code analyzer. 25 | 26 | Within **seconds** it can tell you how your functions and classes are connected to each other! 27 | 28 | ![](/demo.gif) 29 | 30 | 31 | 32 | [Getting started](#getting-started) • 33 | [Installation](#installation) • 34 | [Configuration](#configuration) 35 | 36 |
37 | 38 | ## Getting started 39 | 40 | 41 | ### Usecases: 42 | 1. Onboard to new codebases faster. 43 | 2. Debug code faster [Twitter thread](https://twitter.com/qasim31wani/status/1609677492347981825) 44 | 3. Create share-able versions of your code. Using gctpy.com, you can instantly share your UML diagrams across teams. 45 | 46 | 47 | Generate graph for any python file 48 | ```sh 49 | python -m gct -i path/to/file.py # run gct on a local file 50 | python -m gct -i https://github.com/user_name/path/to/file.py # run gct on a file hosted on a web server 51 | ``` 52 | 53 | 54 | ## Installation 55 | 56 | ### *Step 1: Install GCT Python package* 57 | 58 | ``` 59 | pip install gct-py 60 | ``` 61 | 62 | 63 | ### *Step 2: Install Graphviz executable* 64 | 65 | GCT generates graphs using [graphviz](https://graphviz.org). To get accurate graphs, we highly 66 | recommend using latest graphviz version available for your OS. 67 | 68 | **Skip this step** if you've already installed graphviz executable version. Check the dot version by running: `dot -V`. 69 | 70 |
71 | Windows 72 | 73 | Install graphviz by downloading executable (version >=6.0.1) from [graphviz](https://graphviz.org/download/#windows) website. 74 | 75 |
76 | 77 |
78 | MacOS 79 | 80 | (Optional) more details: [graphviz](https://graphviz.org/download/#mac). 81 | 82 | ``` 83 | brew install graphviz 84 | ``` 85 | 86 |
87 | 88 |
89 | Linux 90 | 91 | (optional) more details: [graphviz](https://graphviz.org/download/#linux). 92 | 93 | ``` 94 | sudo apt install graphviz 95 | ``` 96 | 97 |
98 | 99 | 100 | ## Configuration 101 | 102 | Customize the experience by aliasing `gct`: 103 | ``` 104 | alias gct='python -m gct -i' 105 | gct path/to/file.py 106 | ``` 107 | 108 | 109 | 110 | 111 | -------------------------------------------------------------------------------- /gct/network.py: -------------------------------------------------------------------------------- 1 | import networkx as nx 2 | import uuid 3 | 4 | 5 | class Node: 6 | def __init__( 7 | self, 8 | line_start: int, 9 | line_end: int, 10 | name: str, 11 | type: str = None, 12 | ): 13 | self.line_start = line_start 14 | self.line_end = line_end 15 | self.name = name 16 | self.type = type # options: [function, class] 17 | self.id = uuid.uuid1().hex 18 | 19 | def __repr__(self) -> str: 20 | return f"{self.name} #{self.line_start + 1}" 21 | 22 | 23 | class Graph: 24 | def __init__(self): 25 | self.G = nx.DiGraph() 26 | self._level_clustering = {} 27 | 28 | @property 29 | def level_clustering(self): 30 | return self._level_clustering 31 | 32 | def add_edge(self, node1: Node, node2: Node): 33 | self.G.add_edge(node1, node2) 34 | 35 | def get_all_nodes(self) -> "list[Node]": 36 | return list(self.G.nodes) 37 | 38 | def get_root_node(self) -> Node: 39 | if not self.get_all_nodes(): 40 | return None 41 | return self.get_all_nodes()[0] 42 | 43 | def get_parent_node(self, node: Node) -> Node: 44 | """ 45 | > Given a node, return the parent node 46 | 47 | :param node: The node to get the parent of 48 | :type node: Node 49 | :return: The parent node of the node passed in. 50 | """ 51 | try: 52 | return list(self.G.predecessors(node))[0] 53 | except: 54 | return None # root node 55 | 56 | def get_children_nodes(self, node: Node) -> "list[Node]": 57 | return list(self.G.successors(node)) 58 | 59 | def group_nodes_by_level(self): 60 | if self._level_clustering: 61 | return 62 | 63 | for node in self.get_all_nodes(): 64 | parent_node = self.get_parent_node(node) 65 | if parent_node is None: 66 | continue 67 | self._level_clustering[parent_node] = self.get_children_nodes(parent_node) 68 | 69 | def is_leaf_node(self, node: Node) -> bool: 70 | return len(self.get_children_nodes(node)) == 0 71 | 72 | def print_graph_by_levels(self): 73 | """ 74 | Print the graph by levels. 75 | Example: 76 | ``` 77 | class A: 78 | def b(): 79 | def c(): 80 | def d(): 81 | pass 82 | class B: 83 | def test(): 84 | pass 85 | ``` 86 | Running `print_graph_by_levels()` will print: 87 | ``` 88 | --- A(1, 8, class) --- 89 | b(2, 5, function) 90 | c(3, 5, function) 91 | d(4, 5, function) 92 | B(6, 8, class) 93 | --- B(6, 8, class) --- 94 | test(7, 8, function) 95 | ``` 96 | Note how the nodes are printed by breath-first search order & not depth-first. 97 | Ideally, the output should look something like this: 98 | ``` 99 | --- A(1, 8, class) --- 100 | b(2, 5, function) 101 | c(3, 5, function) 102 | d(4, 5, function) 103 | --- B(6, 8, class) --- 104 | test(7, 8, function) 105 | ``` 106 | But you can leverage information stored in `self._level_clustering` to do this. 107 | """ 108 | self.group_nodes_by_level() 109 | 110 | for parent_node, children_nodes in self._level_clustering.items(): 111 | parent_node: Node = parent_node 112 | children_nodes: "list[Node]" = children_nodes 113 | 114 | print(f"--- {parent_node} ---") 115 | for child_node in children_nodes: 116 | print(f"\t{child_node}") 117 | -------------------------------------------------------------------------------- /gct/api.py: -------------------------------------------------------------------------------- 1 | """ 2 | Graphical Code Tracer (GCT) is a static code analysis tool that generates 3 | a graphical representation of a Python program. It shows how different parts 4 | of the program interact with each other. GCT is built on top of the AST module 5 | and thus isn't always 100% accurate due to the dynamic nature of Python. 6 | 7 | GCT, however, still provides a good overview of the program and can be used 8 | to quickly identify potential bugs, understand the general flow of a program, 9 | and onboard new developers to any python codebase. 10 | 11 | GCT is currently limited to file-level tracing. This means that it can only 12 | trace functions and classes that are defined in the same file. If you enjoy 13 | GCT, please consider contributing to the project to extend its functionality. 14 | https://github.com/QasimWani/gct 15 | 16 | 17 | Running GCT on any python3 file is as simple as: 18 | 19 | >>> import gct.api as api 20 | >>> path = "example/arithmetics.py" 21 | >>> graph, code = api.run(path) 22 | >>> api.render(graph, file_name="temp/graph", output_format="pdf") 23 | 24 | If you want to load the svg object in memory instead of saving it to a file, 25 | leave `file_name` in api.run as None. 26 | >>> svg_as_string = api.run(graph) 27 | 28 | """ 29 | import graphviz 30 | 31 | import gct.utils as utils 32 | from gct.parse import extract 33 | import time 34 | from gct.constants import TEMP_FOLDER, GRAPH_FOLDER_DEFAULT_NAME 35 | 36 | 37 | def run(resource_name: str) -> "list[graphviz.Digraph, str]": 38 | """ 39 | Runs GCT on a given resource and returns the graphviz object. 40 | @Parameter: 41 | 1. resource_name: str = Path to the file/URL to generate graph for. 42 | @Returns: 43 | 1. graphviz.Digraph object. To render the graph, call the render() method on the object. 44 | 2. str: The raw code corresponding to `resource_name`. 45 | """ 46 | # Flush temp folder. If it doesn't exist, create it. 47 | utils.flush(f"{TEMP_FOLDER}/") 48 | 49 | start_time = time.time() 50 | 51 | # Get the AST and raw code 52 | tree, raw_code = utils.parse_file(resource_name) 53 | # Extract relevant components -- node connection and edge mapping 54 | node_representation, edge_representation = extract(tree, raw_code) 55 | # Heirarchical clustering 56 | node_representation.group_nodes_by_level() 57 | # Define graphviz graph 58 | g = graphviz.Digraph("G", filename=f"{TEMP_FOLDER}/graph", engine="dot") 59 | g.attr(compound="true", rankdir="LR", ranksep="1.0") 60 | 61 | # Create visual graph representation 62 | root = node_representation.get_root_node() 63 | if root: 64 | utils.add_subgraphs(node_representation, g, root) 65 | 66 | # create edges 67 | edges = list(edge_representation.G.edges) 68 | for u, v in edges: 69 | g.edge(u.id, v.id) 70 | 71 | print(f"Successfully generated graph in {time.time() - start_time:.2f} seconds") 72 | return g, "\n".join(raw_code) 73 | 74 | raise Exception("No user-defined functions/class definitions found.") 75 | 76 | 77 | def render( 78 | graph: graphviz.Digraph, file_path: str = None, output_format: str = "svg" 79 | ) -> str: 80 | """ 81 | Renders the graphviz object to a file. 82 | @Parameters: 83 | 1. graphviz_object: graphviz.Digraph = Graphviz object to render. 84 | 2. file_path: str = file path to save the output to. If None, the svg output (str) will be returned. 85 | 3. output_format: str = Output format. Defaults to svg. Other formats include "png", "pdf". 86 | """ 87 | updated_file_path = ( 88 | f"{TEMP_FOLDER}/{GRAPH_FOLDER_DEFAULT_NAME}" 89 | if file_path is None 90 | else file_path 91 | ) 92 | 93 | graph.render(updated_file_path, format=output_format, view=file_path is not None) 94 | 95 | if file_path is None: 96 | # Read the svg file and return it as a string 97 | with open(f"{updated_file_path}.{output_format}", "r") as f: 98 | result = f.read() 99 | utils.flush(f"{TEMP_FOLDER}/") 100 | return result 101 | 102 | return "" 103 | -------------------------------------------------------------------------------- /gct/type_check.py: -------------------------------------------------------------------------------- 1 | import ast 2 | from gct.network import Node, Graph 3 | from gct.constants import NODE_NAMES_TO_IGNORE 4 | from collections import namedtuple 5 | 6 | 7 | class Metadata( 8 | namedtuple( 9 | "Metadata", ["tree", "raw_code", "node_graph", "node_line_map", "parent_lineno"] 10 | ) 11 | ): 12 | tree: ast 13 | raw_code: "list[str]" 14 | node_graph: Graph 15 | node_line_map: "dict[int, Node]" 16 | parent_lineno: int # Line number where function of interest is defined 17 | 18 | 19 | def helper_search_definition(tree, variable_name): 20 | """ 21 | Recursive function to search for the definition of a variable in an AST. 22 | Note: This only searches the latest definition of a variable since Python is dynamically typed. 23 | So the results may not be accurate if the variable is redefined. 24 | 25 | E.g.: 26 | ``` 27 | class A: 28 | def func(self): 29 | pass 30 | var = A() 31 | x = var.func() 32 | ``` 33 | In this case, we want to find the definition of `var` in the AST. 34 | Using the AST, we can find the definition of `var` in the `Assign` node. 35 | We can also have multiple targets in the assignment. E.g: 36 | ``` 37 | class A: 38 | def func(self): 39 | pass 40 | temp, var = None, A() 41 | x = var.func() 42 | ``` 43 | In this case, var is defined in the `Assign` node with two targets. This is stored as an ast.Tuple node. 44 | So we must traverse through all the elements in the tuple to find the definition corresponding to `var`. 45 | """ 46 | 47 | # Iterate through the nodes in the AST 48 | for node in ast.iter_child_nodes(tree): 49 | # Both cases work only if the node is of type `Assign` 50 | if isinstance(node, ast.Assign): 51 | 52 | for target in node.targets: 53 | # case I: target is a single variable 54 | if isinstance(target, ast.Name) and target.id == variable_name: 55 | return node 56 | 57 | # case II: target is a tuple 58 | if isinstance(target, ast.Tuple): 59 | for el in target.elts: 60 | if isinstance(el, ast.Name) and el.id == variable_name: 61 | return node 62 | 63 | # Recursively search for the definition in child nodes 64 | definition = helper_search_definition(node, variable_name) 65 | if definition: 66 | return definition 67 | return None 68 | 69 | 70 | def search_for_definition(tree: ast, name: str) -> list: 71 | """ 72 | Find where a variable has been defined. 73 | @Parameters: 74 | 1. tree: ast = AST of the file. 75 | 2. name: str = name of variable to search for. 76 | @Returns: list of potential targets for the variable. If empty, no target has been found. 77 | """ 78 | if name in NODE_NAMES_TO_IGNORE: 79 | return [] 80 | 81 | result = helper_search_definition(tree, name) 82 | potential_target_nodes = [] 83 | 84 | if not result: 85 | return potential_target_nodes 86 | try: 87 | if isinstance(result.value, ast.Call): 88 | if isinstance(result.value.func, ast.Attribute): 89 | potential_target_nodes.append(result.value.func.attr) 90 | else: 91 | if isinstance(result.value.func, ast.Name): 92 | potential_target_nodes.append(result.value.func.id) 93 | elif isinstance( 94 | result.value.func, ast.Subscript 95 | ): # BUG: this is a hacky fix for the case where the function is a subscript 96 | potential_target_nodes.append(result.value.func.value.id) 97 | elif isinstance(result.value, ast.Tuple): 98 | for node in result.value.elts: 99 | if isinstance(node, ast.Call): 100 | potential_target_nodes.append(node.func.id) 101 | elif isinstance(node, ast.Name): 102 | potential_target_nodes.append(node.id) 103 | except Exception as e: 104 | print(f"Error: {e}") 105 | 106 | return potential_target_nodes 107 | 108 | 109 | def get_prefix_and_suffix(name: str) -> "tuple[str, str]": 110 | """ 111 | Given a function name, return the prefix and suffix. 112 | E.g.: 113 | ``` 114 | 1. Class.func --> prefix is `Class` and suffix is `func` 115 | 2. func --> prefix is None and suffix is `func` 116 | 3. module.Class.func --> prefix is `module.Class` and suffix is `func` 117 | ``` 118 | Note: we ignore (3) for now since GCT currently only handles file-level tracing. This means that we're also 119 | not including subclasses that belong to the same file. It's pretty uncommon to have multiple subclasses in the same file. 120 | So to keep things simple for now and optimize for the common case, it's fine to ignore this. But in the future, 121 | this should be handled. 122 | 123 | @Parameters: 124 | 1. name: str = name of function of interest. 125 | @Returns: tuple of prefix and suffix. 126 | """ 127 | prefix = None 128 | suffix = name 129 | 130 | if "." in name: 131 | splits = name.split(".") 132 | if len(splits) == 2: 133 | prefix, suffix = splits 134 | else: 135 | suffix = splits[-1] 136 | return prefix, suffix 137 | 138 | 139 | def infer_complex_mappings(prefix: str, suffix: str, metadata: Metadata): 140 | """ 141 | Infer mappings for complex cases. 142 | E.g.: 143 | ``` 144 | 1. Class.func 145 | 2. c.func(), where c = Class 146 | ``` 147 | Case I is trivial. We just need to find the node with prefix. And get all chldren from that node that has suffix. 148 | Case II is a bit more tricky. We need to find the code definition of c, and then find the node with correct prefix. 149 | From there, we can get all children with suffix. 150 | @Parameters: 151 | 1. prefix: str = prefix of function name. 152 | 2. suffix: str = suffix of function name. 153 | 3. metadata: Metadata = metadata for the file. 154 | """ 155 | tree: ast = metadata.tree 156 | node_graph: Graph = metadata.node_graph 157 | node_line_map: "dict[int, Node]" = metadata.node_line_map 158 | potential_target_nodes: "list[Node]" = [] 159 | 160 | # Case I: prefix is a class/method name 161 | prefix_target_nodes = find_nodes_by_name(prefix, node_line_map.values()) 162 | # get children nodes for each prefix node 163 | for node in prefix_target_nodes: 164 | children_nodes = node_graph.get_children_nodes(node) 165 | suffix_target_nodes = find_nodes_by_name(suffix, children_nodes) 166 | potential_target_nodes.extend(suffix_target_nodes) 167 | 168 | # Case II: prefix is a variable 169 | if not potential_target_nodes: 170 | potential_names = search_for_definition(tree, prefix) 171 | 172 | for potential_name in potential_names: 173 | prefix_target_nodes = find_nodes_by_name( 174 | potential_name, node_line_map.values() 175 | ) 176 | for node in prefix_target_nodes: 177 | children_nodes = node_graph.get_children_nodes(node) 178 | suffix_target_nodes = find_nodes_by_name(suffix, children_nodes) 179 | potential_target_nodes.extend(suffix_target_nodes) 180 | 181 | return potential_target_nodes 182 | 183 | 184 | def find_nodes_by_name(target_node_name: str, nodes: "list[Node]") -> "list[Node]": 185 | """ 186 | Find all nodes with the given name. 187 | @Parameters: 188 | 1. target_node_name: str = name of node to search for. 189 | 2. nodes: list[Node] = list of nodes to search through. 190 | @Returns: list of nodes with the given `target_node_name`. 191 | """ 192 | potential_target_nodes: "list[Node]" = [] 193 | for node in nodes: 194 | if node.name == target_node_name: 195 | potential_target_nodes.append(node) 196 | return potential_target_nodes 197 | 198 | 199 | def infer_direct_mappings(node_line_map: "dict[int, Node]", name: str) -> "list[Node]": 200 | """ 201 | Handles the case where the function of interest is a direct mapping to a node. 202 | E.g.: 203 | ``` 204 | def func(): 205 | pass 206 | func() 207 | ``` 208 | In this case, `func` is a direct mapping to the `Node` object corresponding to the function definition. 209 | 210 | @Parameters: 211 | 1. node_line_map: dict[int, Node] = maps line number to Node object. 212 | 2. suffix: str = suffix of function of interest. 213 | @Returns: list of potential targets for the function of interest. 214 | """ 215 | return find_nodes_by_name(name, node_line_map.values()) 216 | -------------------------------------------------------------------------------- /gct/utils.py: -------------------------------------------------------------------------------- 1 | import ast 2 | from gct.network import Node, Graph 3 | import random 4 | import gct.type_check as type_check 5 | import gct.constants as constants 6 | import graphviz 7 | import os 8 | import shutil 9 | import requests 10 | 11 | 12 | def generate_random_color(): 13 | """Generate random color in hex format with alpha channel set to 60""" 14 | return f"#{random.randint(0, 255):02x}{random.randint(0, 255):02x}{random.randint(0, 255):02x}60" 15 | 16 | 17 | def save_code_to_file(code: str, resource: str): 18 | if "/" in resource: 19 | resource = resource.split("/")[-1] 20 | if not resource.endswith(".py"): 21 | resource = resource + ".py" 22 | with open(f"{constants.TEMP_FOLDER}/{resource}", "w") as f: 23 | f.write(code) 24 | 25 | 26 | def flush(path: str): 27 | # if folder doesn't exist, create it and exit. If it does exist, remove all files and create a new temp folder. 28 | if not os.path.exists(path): 29 | os.mkdir(path) 30 | else: 31 | for file in os.listdir(path): 32 | file_path = os.path.join(path, file) 33 | try: 34 | if os.path.isfile(file_path) or os.path.islink(file_path): 35 | os.unlink(file_path) 36 | elif os.path.isdir(file_path): 37 | shutil.rmtree(file_path) 38 | except Exception as e: 39 | print("Failed to delete %s. Reason: %s" % (file_path, e)) 40 | 41 | 42 | def parse_file(resource: str): 43 | """ 44 | A resource can either be: 45 | 1. URL - in which case we fetch the code and parse it. 46 | 2. Path to a file - in which case we read the file and parse it. 47 | 3. Raw code - in which case we parse it directly. 48 | """ 49 | if resource.startswith("http"): 50 | response = requests.get(resource) 51 | tree = ast.parse(response.text, filename=resource) 52 | return tree, response.text.splitlines() 53 | elif resource.endswith(".py"): 54 | with open(resource, "r") as f: 55 | tree = ast.parse(f.read(), filename=resource) 56 | f.seek(0) 57 | return tree, f.readlines() 58 | else: 59 | tree = ast.parse(resource) 60 | return tree, resource.splitlines() 61 | 62 | 63 | def get_indent_number(line: str): 64 | return len(line) - len(line.lstrip()) 65 | 66 | 67 | def get_end_of_function(lines: "list[str]", lineno: int): 68 | """ 69 | Fetches the end of a function definition by comparing indentation number of the 70 | first line with the indentation of potential end function. 71 | @Parameters: 72 | 1. filename: str = file containing function. 73 | 2. lineno: int = line number (0-based indexing) where function of interest starts from. 74 | @Returns: line number where the function ends. 75 | """ 76 | start_indent = get_indent_number(lines[lineno]) 77 | for i in range(lineno + 1, len(lines)): 78 | line = lines[i] 79 | if ( 80 | get_indent_number(line) <= start_indent 81 | and line.strip() 82 | and not line.strip().startswith(")") 83 | ): 84 | return i - 1 85 | return len(lines) - 1 86 | 87 | 88 | def fetch_full_function(lines: "list[str]", start_lineno: int) -> "list[str]": 89 | end_lineno = get_end_of_function(lines, start_lineno) 90 | return lines[start_lineno : end_lineno + 1] 91 | 92 | 93 | def is_call_node_in_function_of_interest( 94 | lines: "list[str]", call_node_name: str 95 | ) -> bool: 96 | if not call_node_name: 97 | # used in node connection logic. In this case, since we only consider 98 | # function calls, we don't need to check if call_node_name is defined 99 | # since it's guaranteed that the function node name is unique and only 100 | # defined once in the output of `fetch_full_function` 101 | return True 102 | 103 | for line in lines: 104 | # check if a line is comment 105 | if line.strip().startswith("#"): 106 | continue 107 | if call_node_name in line: 108 | return True 109 | return False 110 | 111 | 112 | def is_line_function_or_class(line: str): 113 | if line.lstrip().split(" ")[0] == "def" or line.lstrip().split(" ")[0] == "class": 114 | return True 115 | return False 116 | 117 | 118 | def get_immediate_parent(lines: "list[str]", lineno: int, call_node_name: str = None): 119 | """ 120 | Given a function, fx, find the most immediate parent node. 121 | In this case, most immediate parent node is the first instance where 122 | the indentation number is lesser than fx. 123 | E.g.: 124 | ``` 125 | def X(): #1 126 | def Y(): #2 127 | //code #3 128 | ``` 129 | In this case, if `Y` is our function of interest, the most immediate 130 | parent node is function `X` defined at line #1. Core logic is similar 131 | to `get_end_of_function`, except now we traverse upwards. 132 | Note that this is not usually the case. Take for example: 133 | ``` 134 | def X(): #1 135 | if True: 136 | def Y(): #2 137 | //code #3 138 | ``` 139 | Based on logic above, the most immediate parent node to `Y` should be `if True`, 140 | but that is not a function or class. Hence, we need to traverse upwards until 141 | we find a function, class, or we reach the root node. Root node is when indentation 142 | level is 0. 143 | To summarize, the two cases to consider: 144 | 1. Root node: indentation level is 0 --> return -1 145 | 2. Function or class node: return line number for that function/class 146 | 147 | @Parameters: 148 | 1. lines: list[str] = relevant lines of code. 149 | 2. lineno:int = line number (0-based indexing) where function of interests starts from. 150 | 3. call_node_name: str = name of function of interest. 151 | @Returns: line number of immediate parent node. 152 | """ 153 | assert lineno < len(lines), "lineno out of range" 154 | 155 | if lineno < 0: 156 | return -1 # root node 157 | 158 | start_indent = get_indent_number(lines[lineno]) 159 | 160 | if start_indent == 0: # at root level 161 | return -1 162 | 163 | for i in range(lineno, -1, -1): 164 | line = lines[i] 165 | 166 | ind_num = get_indent_number(line) 167 | if ind_num >= start_indent or not line.strip(): 168 | continue 169 | if is_line_function_or_class(line): 170 | # check if call_node_name is defined in the extracted function 171 | function_of_interest = fetch_full_function(lines, i) 172 | if is_call_node_in_function_of_interest( 173 | function_of_interest, call_node_name 174 | ): 175 | return i 176 | if ind_num == 0 and not line.strip().startswith(")"): # root node 177 | return -1 178 | 179 | raise ValueError(f"No parent found. source line: {lineno}") 180 | 181 | 182 | def find_function_of_interest(name: str, metadata: type_check.Metadata) -> "list[Node]": 183 | """ 184 | Given a function name, find the function of interest in the node_line_map. 185 | Ignoring class definition calls for now. 186 | 187 | @Parameters: 188 | 1. node_line_map: dict[int, Node] = maps line number to Node object. 189 | 2. name: str = name of function of interest. 190 | @Returns: list of potential target `Node` for function of interest. 191 | """ 192 | prefix, suffix = type_check.get_prefix_and_suffix(name) 193 | 194 | potential_target_nodes: "list[Node]" = [] 195 | 196 | if prefix: 197 | if prefix == constants.SELF_NODE_NAME: 198 | # get 2nd level parent node 199 | bilevel_parent_lineno = get_immediate_parent( 200 | metadata.raw_code, metadata.parent_lineno, name 201 | ) 202 | # get node name at bilevel parent node line number 203 | if bilevel_parent_lineno != constants.ROOT_NODE_LINENO: 204 | bilevel_parent_node = metadata.node_line_map[bilevel_parent_lineno] 205 | prefix = bilevel_parent_node.name 206 | 207 | potential_target_nodes = type_check.infer_complex_mappings( 208 | prefix, suffix, metadata 209 | ) 210 | else: 211 | potential_target_nodes = type_check.infer_direct_mappings( 212 | metadata.node_line_map, suffix 213 | ) 214 | 215 | return potential_target_nodes 216 | 217 | 218 | def add_subgraphs( 219 | node_representation: Graph, 220 | graphviz_graph: graphviz.Digraph, 221 | root: Node, 222 | visited: set = set(), 223 | ): 224 | """Recursively traverse (depth-first) the graph, `g`, and add corresponding subgraph to `root`.""" 225 | 226 | for node in node_representation.G.successors(root): 227 | node: Node = node 228 | if node in visited: 229 | continue 230 | visited.add(node) 231 | if not node_representation.is_leaf_node(node): # create subgraph 232 | with graphviz_graph.subgraph(name=f"{node.id}") as c: 233 | c.node(node.id, style="invis", fontsize="0") 234 | 235 | bgcolor = "transparent" 236 | text = node.__repr__() 237 | if node.type == "class": 238 | text = f"< {text} >" 239 | bgcolor = generate_random_color() 240 | 241 | c.attr( 242 | style="rounded", 243 | label=text, 244 | color="black", 245 | cluster="true", 246 | bgcolor=bgcolor, 247 | ) 248 | add_subgraphs(node_representation, c, node, visited) 249 | else: 250 | text = node.__repr__() 251 | style = "rounded" 252 | bgcolor = "transparent" 253 | shape = "" 254 | 255 | if node.type == "class": 256 | text = f"< {node.__repr__()} >" 257 | style = "rounded, filled" 258 | shape = "box" 259 | bgcolor = generate_random_color() 260 | 261 | graphviz_graph.node( 262 | node.id, 263 | text, 264 | style=style, 265 | shape=shape, 266 | fillcolor=bgcolor, 267 | ) 268 | 269 | add_subgraphs(node_representation, graphviz_graph, node, visited) 270 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. 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No Surrender of Others' Freedom. 541 | 542 | If conditions are imposed on you (whether by court order, agreement or 543 | otherwise) that contradict the conditions of this License, they do not 544 | excuse you from the conditions of this License. If you cannot convey a 545 | covered work so as to satisfy simultaneously your obligations under this 546 | License and any other pertinent obligations, then as a consequence you may 547 | not convey it at all. For example, if you agree to terms that obligate you 548 | to collect a royalty for further conveying from those to whom you convey 549 | the Program, the only way you could satisfy both those terms and this 550 | License would be to refrain entirely from conveying the Program. 551 | 552 | 13. Use with the GNU Affero General Public License. 553 | 554 | Notwithstanding any other provision of this License, you have 555 | permission to link or combine any covered work with a work licensed 556 | under version 3 of the GNU Affero General Public License into a single 557 | combined work, and to convey the resulting work. The terms of this 558 | License will continue to apply to the part which is the covered work, 559 | but the special requirements of the GNU Affero General Public License, 560 | section 13, concerning interaction through a network will apply to the 561 | combination as such. 562 | 563 | 14. Revised Versions of this License. 564 | 565 | The Free Software Foundation may publish revised and/or new versions of 566 | the GNU General Public License from time to time. Such new versions will 567 | be similar in spirit to the present version, but may differ in detail to 568 | address new problems or concerns. 569 | 570 | Each version is given a distinguishing version number. If the 571 | Program specifies that a certain numbered version of the GNU General 572 | Public License "or any later version" applies to it, you have the 573 | option of following the terms and conditions either of that numbered 574 | version or of any later version published by the Free Software 575 | Foundation. If the Program does not specify a version number of the 576 | GNU General Public License, you may choose any version ever published 577 | by the Free Software Foundation. 578 | 579 | If the Program specifies that a proxy can decide which future 580 | versions of the GNU General Public License can be used, that proxy's 581 | public statement of acceptance of a version permanently authorizes you 582 | to choose that version for the Program. 583 | 584 | Later license versions may give you additional or different 585 | permissions. However, no additional obligations are imposed on any 586 | author or copyright holder as a result of your choosing to follow a 587 | later version. 588 | 589 | 15. Disclaimer of Warranty. 590 | 591 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY 592 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT 593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY 594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, 595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 596 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM 597 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF 598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 599 | 600 | 16. Limitation of Liability. 601 | 602 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS 604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY 605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE 606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF 607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD 608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF 610 | SUCH DAMAGES. 611 | 612 | 17. Interpretation of Sections 15 and 16. 613 | 614 | If the disclaimer of warranty and limitation of liability provided 615 | above cannot be given local legal effect according to their terms, 616 | reviewing courts shall apply local law that most closely approximates 617 | an absolute waiver of all civil liability in connection with the 618 | Program, unless a warranty or assumption of liability accompanies a 619 | copy of the Program in return for a fee. 620 | 621 | END OF TERMS AND CONDITIONS 622 | 623 | How to Apply These Terms to Your New Programs 624 | 625 | If you develop a new program, and you want it to be of the greatest 626 | possible use to the public, the best way to achieve this is to make it 627 | free software which everyone can redistribute and change under these terms. 628 | 629 | To do so, attach the following notices to the program. It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | 635 | Copyright (C) 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see . 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | Copyright (C) 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | . 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | . 675 | --------------------------------------------------------------------------------