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| author | Eli Bendersky <eliben@gmail.com> | 2012-12-25 05:34:22 -0800 |
|---|---|---|
| committer | Eli Bendersky <eliben@gmail.com> | 2012-12-25 05:34:22 -0800 |
| commit | 0d0b4d5b4886f2739f468862412fcf74f4d60bd6 (patch) | |
| tree | 81a2094a05313d33eb4aef5caab1eb9b941ef3fc /README.rst | |
| parent | 933525181bdbb81b4a3b7aea011b9cb6ff223693 (diff) | |
| download | pycparser-0d0b4d5b4886f2739f468862412fcf74f4d60bd6.tar.gz | |
renaming README file to be auto-rendered by bitbucket
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diff --git a/README.rst b/README.rst new file mode 100644 index 0000000..3e48630 --- /dev/null +++ b/README.rst @@ -0,0 +1,159 @@ +===============
+pycparser v2.09
+===============
+
+:Author: `Eli Bendersky <http://eli.thegreenplace.net>`_
+
+
+.. contents::
+ :backlinks: none
+
+.. sectnum::
+
+
+Introduction
+============
+
+What is pycparser?
+------------------
+
+``pycparser`` is a parser for the C language, written in pure Python. It is a module designed to be easily integrated into applications that need to parse C source code.
+
+What is it good for?
+--------------------
+
+Anything that needs C code to be parsed. The following are some uses for ``pycparser``, taken from real user reports:
+
+* C code obfuscator
+* Front-end for various specialized C compilers
+* Static code checker
+* Automatic unit-test discovery
+* Adding specialized extensions to the C language
+
+``pycparser`` is unique in the sense that it's written in pure Python - a very high level language that's easy to experiment with and tweak. To people familiar with Lex and Yacc, ``pycparser``'s code will be simple to understand.
+
+
+Which version of C does pycparser support?
+------------------------------------------
+
+``pycparser`` aims to support the full C99 language (according to the standard ISO/IEC 9899). This is a new feature in the version 2.x series - earlier versions only supported C89. For more information on the change, read `this wiki page <http://code.google.com/p/pycparser/wiki/C99support>`_.
+
+``pycparser`` doesn't support any GCC extensions. See the `FAQ <http://code.google.com/p/pycparser/wiki/FAQ>`_ for more details.
+
+What grammar does pycparser follow?
+-----------------------------------
+
+``pycparser`` very closely follows the C grammar provided in the end of the C99 standard document
+
+How is pycparser licensed?
+--------------------------
+
+`New BSD License <http://www.opensource.org/licenses/bsd-license.php>`_
+
+Contact details
+---------------
+
+Drop me an email to eliben@gmail.com for any questions regarding ``pycparser``. For reporting problems with ``pycparser`` or submitting feature requests, the best way is to open an issue on the `pycparser page at Google Code <http://code.google.com/p/pycparser/>`_.
+
+
+Installing
+==========
+
+Prerequisites
+-------------
+
+* ``pycparser`` was tested on Python 2.6, 2.7 and 3.2, on both Linux and Windows. It should work on any later version (in both the 2.x and 3.x lines) as well.
+* ``pycparser`` uses the PLY module for the actual lexer and parser construction. Install PLY from `its website <http://www.dabeaz.com/ply/>`_.
+
+Installation process
+--------------------
+
+Installing ``pycparser`` is very simple. Once you download it from its `website <http://code.google.com/p/pycparser/>`_ and unzip the package, you just have to execute the standard ``python setup.py install``. The setup script will then place the ``pycparser`` module into ``site-packages`` in your Python's installation library.
+
+Alternatively, since ``pycparser`` is listed in the `Python Package Index <http://pypi.python.org/pypi/pycparser>`_ (PyPI), you can install it using your favorite Python packaging/distribution tool, for example with::
+
+ > pip install pycparser
+
+It's recommended to run ``_build_tables.py`` in the ``pycparser`` code directory after installation to make sure the parsing tables of PLY are pre-generated. This can make your code run faster.
+
+Known problems
+--------------
+
+* Some users who've installed a new version of ``pycparser`` over an existing version ran into a problem using the newly installed library. This has to do with parse tables staying around as ``.pyc`` files from the older version. If you see unexplained errors from ``pycparser`` after an upgrade, remove it (by deleting the ``pycparser`` directory in your Python's ``site-packages``, or wherever you installed it) and install again.
+
+Using
+=====
+
+Interaction with the C preprocessor
+-----------------------------------
+
+In order to be compilable, C code must be preprocessed by the C preprocessor - ``cpp``. ``cpp`` handles preprocessing directives like ``#include`` and ``#define``, removes comments, and does other minor tasks that prepare the C code for compilation.
+
+For all but the most trivial snippets of C code, ``pycparser``, like a C compiler, must receive preprocessed C code in order to function correctly. If you import the top-level ``parse_file`` function from the ``pycparser`` package, it will interact with ``cpp`` for you, as long as it's in your PATH, or you provide a path to it.
+
+On the vast majority of Linux systems, ``cpp`` is installed and is in the PATH. If you're on Windows and don't have ``cpp`` somewhere, you can use the one provided in the ``utils`` directory in ``pycparser``'s distribution. This ``cpp`` executable was compiled from the `LCC distribution <http://www.cs.princeton.edu/software/lcc/>`_, and is provided under LCC's license terms.
+
+What about the standard C library headers?
+------------------------------------------
+
+C code almost always includes various header files from the standard C library, like ``stdio.h``. While, with some effort, ``pycparser`` can be made to parse the standard headers from any C compiler, it's much simpler to use the provided "fake" standard includes in ``utils/fake_libc_include``. These are standard C header files that contain only the bare necessities to allow valid parsing of the files that use them. As a bonus, since they're minimal, it can significantly improve the performance of parsing large C files.
+
+The key point to understand here is that ``pycparser`` doesn't really care aabout the semantics of types. It only needs to know whether some token encountered in the source is a previously defined type. This is essential in order to be able to parse C correctly.
+
+See the ``using_cpp_libc.py`` example for more details.
+
+Basic usage
+-----------
+
+Take a look at the ``examples`` directory of the distribution for a few examples of using ``pycparser``. These should be enough to get you started.
+
+Advanced usage
+--------------
+
+The public interface of ``pycparser`` is well documented with comments in ``pycparser/c_parser.py``. For a detailed overview of the various AST nodes created by the parser, see ``pycparser/_c_ast.cfg``.
+
+There's also a `FAQ available here <http://code.google.com/p/pycparser/wiki/FAQ>`_. In any case, you can always drop me an `email <eliben@gmail.com>`_ for help.
+
+Modifying
+=========
+
+There are a few points to keep in mind when modifying ``pycparser``:
+
+* The code for ``pycparser``'s AST nodes is automatically generated from a configuration file - ``_c_ast.cfg``, by ``_ast_gen.py``. If you modify the AST configuration, make sure to re-generate the code.
+* Make sure you understand the optimized mode of ``pycparser`` - for that you must read the docstring in the constructor of the ``CParser`` class. For development you should create the parser without optimizations, so that it will regenerate the Yacc and Lex tables when you change the grammar.
+
+
+Package contents
+================
+
+Once you unzip the ``pycparser`` package, you'll see the following files and directories:
+
+README.txt/html:
+ This README file.
+
+setup.py:
+ Installation script
+
+examples/:
+ A directory with some examples of using ``pycparser``
+
+pycparser/:
+ The ``pycparser`` module source code.
+
+tests/:
+ Unit tests.
+
+utils/cpp.exe:
+ A Windows executable of the C pre-processor suitable for working with pycparser
+
+utils/fake_libc_include:
+ Minimal standard C library include files that should allow to parse any C code.
+
+utils/internal/:
+ Internal utilities for my own use. You probably don't need them.
+
+Contributors
+============
+
+Some people have contributed to ``pycparser`` by opening issues on bugs they've found and/or submitting patches. The list of contributors is at `this pycparser Wiki page <http://code.google.com/p/pycparser/wiki/Contributors>`_.
+
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