C Metaprogramming Utilities

This package provides utilities for manipulating C programs.

1 Getting Started

The easiest way to get started using the C metaprogramming utilities is with the main module:

(require (planet dherman/c:3:2))

This module provides everything in the entire package. Subsequent sections of this manual describe the functionality of the individual libraries included, which can also be required individually.

Examples:

> (define time.h     (header      (struct tm ([int tm_sec]                  [int tm_min]                  [int tm_hour]                  [int tm_mday]                  [int tm_mon]                  [int tm_year]                  [int tm_wday]                  [int tm_yday]                  [int tm_isdst])))) > (define time     (compile-header time.h                     (system-compiler #:include<> '("time.h") gcc))) > (layout-offset (time 'tm) 'tm_year) 20

Binary layout information is especially useful for interacting with the foreign library—see FFI: Racket Foreign Interface. For example, the procedures ptr-ref and ptr-set! can be used to read and write from arbitrary addresses, which can be computed using layout information.

2 Libraries Provided by this Package

This package includes:

• A library of abstract syntax for the C99 language–see (part "syntax")

• A library for parsing C99 programs–see (part "parsing")

• A (preliminary) library providing S-expression syntax for C–see (part "pc")

• A library for compiling and running C programs with an external compiler–see (part "eval")

• A library for compiling C header information–see (part "header")

3 Known Limitations

The parser does not recognize the C preprocessor. I may attempt to implement the preprocessor in the future, but there’s no guarantee at this point.

The grammar does not support any extensions for GCC, MSVC, or any other specific C implementations. I intend to add support for these extensions on a by-need basis. Specific requests (as well as patches) are welcome.

External compilation is currently limited to GCC. I intend to add support for additional compilers on a by-need basis; patches are welcome.

4 Feedback and Bug Reports

Before sending feedback or bug reports, please consult the current set of registered issues. If you cannot find your issue there, feel free to file a new bug report in the online issue database.

Any other feedback may be emailed to me, Dave Herman, at dherman@ccs.neu.edu.

5 History

• Version 0.1 (2009-02-01) - Initial release. Reasonably usable for header extraction.

• Version 0.2 (2009-03-09) - Full C99 parser implemented.

• Version 0.3 (2009-03-31) - Some cleanup of the AST API.

• Version 0.4 (2009-09-16) - Fixed parser bug 202: the grammar should be complete now.