chanfried / pyclasvi

Python Clang AST Viewer

PyClASVi - Python Clang AST Viewer

Python Clang AST Viewer is a simple GUI program helping you to understand the Clang Abstract Syntax Tree

This tool is helpful if you want to use the Python binding for clang library, e.g. for a code generator. This binding use the c interface (not c++). So if you plan to use the c interface PyClASVi may also help you but be award the python binding may have some differences.

The goal is to make this program runable on all systems supported by Clang and Python independent of Clang and Python version or support at least as many different versions as possible. Currently PyClASVi is tested under Ubuntu and Windows 10 with Python 2.7 and Python 3 using different Clang versions starting at 3.3. Not all combinations are tested but I thing it works nearly everywhere with nearly every versions.

Getting Started

Depending on your operation system you need to install different things like:

• Python
• tk for Python
• Clang or just the library
• Compiler with standard header
• Clang Python binding

Linux

This was tested with Ubuntu 14.04 and 16.04.

First you need to install Clang, Clang Indexing Library Bindings for Python and tk for Python.

For Python 2 you can run this:

sudo apt-get install libclang1-3.8 python-clang-3.8 python-tk

Some older versions of Python clang binding do not support Python 3. For clang up to version 3.9 you can use libclang-py3 instead. For Python 3 you can run this:

sudo apt-get install clang-3.8 python3-pip python3-tk
sudo pip3 install libclang-py3==3.8

Instead of libclang1-3.8 you can install the complete compiler using clang-3.8 and of course you can use everey supported version.

Now you can run the file pyclasvi.py but you may get an error. Clang Python binding is looking for libclang.so or libclang-<version>.so but Ubuntu install something like libclang.so.1 or libclang-3.8.so.1. Use the -l option to set the used library. This is also fine if you have differed versions installed.

To run PyClASVi just call ./pyclasvi.py -l /usr/lib/llvm-3.8/lib/libclang.so.1.

You will see a tabbed window. The first tab is the Input frame. Select a file to parse and add some arguments for the Clang parser. There must be only one argument per line. It looks like you need also the standard includes like -I/usr/include and -I/usr/include/clang/3.8/include.

Press [Parse] to start the parser.

If all works fine there is no warning or error on the Error tab and the Output tab shows the AST on the left. Select one entry (Clang calls it Cursor) to find more information on the right.

Windows

First download and install Python (http://www.python.org). Do not use the embeddable zip file, it does not include Tcl/tk.

Also download and install Clang as part of the LLVM project (http://llvm.org/). If you check the option to set the PATH variable you don't need to do it later. LLVM do not install any standard libraries or headers so you need to install an extra compiler. As default VisualStudio is used.

Install clang python binding using pip. If you want a special version, e.g. 5.0, you can enter the following command.

py -m pip install clang==5.0

To run PyClASVi enter the following commands:

set PATH=%PATH%;C:\Program Files\LLVM\bin
py pyclasvi.py

You don't need the first line if you checked the corresponding option while installing LLVM.

Documentation

How to use Python Clang AST Viewer

How to use Python Clang

License

PyClASVi is distributed under the MIT License.