A Safe Dialect of C Download! Cyclone Version 0.3 (4.9MB, 18 Apr 2002) Read! the documentation (download) Join! Cyclone mailing lists or send comments Cyclone is mirrored at Cornell and AT&T Labs Research.

Synopsis

Cyclone is a programming language based on C that is safe, meaning that it rules out programs that have buffer overflows, dangling pointers, format string attacks, and so on. High-level, type-safe languages, such as Java, Scheme, or ML also provide safety, but they don't give the same control over data representations and memory management that C does (witness the fact that the run-time systems for these languages are usually written in C.) Furthermore, porting legacy C code to these languages or interfacing with legacy C libraries is a difficult and error-prone process. The goal of Cyclone is to give programmers the same low-level control and performance of C without sacrificing safety, and to make it easy to port or interface with legacy C code.

Cyclone achieves safety while remaining compatible with C by:

• Enforcing type safety (e.g., a cast from t1 to t2 is allowed only if it is safe to view a t1 as a t2)
• Not changing data representation or calling conventions
• Providing region-based, manual memory management
• Using a combination of type information and run-time checks to prevent array-bound violations
• Wrapping the C standard library with appropriate run-time checks as necessary (e.g., has a FILE already been closed)

• Tagged unions
• Parametric polymorphism
• Pattern matching
• Exceptions
• Anonymous structs equivalent by structure
• Parameterized typedefs
• An extensive library for container types and other common utilities
• A lexer generator and parser generator
• Function-level debugging with gdb and profiling with gprof

Software Distribution

The Cyclone compiler and tools, as well as some benchmark programs, are freely available for download.

System Requirements:

• Cyclone is currently supported on x86 Linux, and on Windows using Cygwin (version 1.3.3). Other platforms may or may not work (our install process tries to detect your configuration and automatically create the necessary platform-specific information).  We have had some success on BSD, Irix, and Solaris systems, but your mileage may vary.  In particular, system-dependent behavior is largely untested.
• You need to extract the files from the "gzipped tarball" using gunzip and tar; under Windows, you can also do this with Winzip.
• You need GNU make, a fairly recent version of gcc (we recommend version 2.95), a bash or ksh shell, and various common utilities (awk, sed, grep). If you are using Cygwin, all of these come with it. gcc and the utilities must be in your path. Other make programs and C compilers will not work.
• See the file INSTALL in the distribution for details.

Licensing: The files in the distribution come from a variety of sources and so come under a variety of licenses. Please see each file and directory for its licensing terms.

Papers

Cyclone: A Safe Dialect of C, Trevor Jim, Greg Morrisett, Dan Grossman, Michael Hicks, James Cheney, and Yanling Wang.  USENIX Annual Technical Conference, Monterey, CA, June 2002. To appear. 
PS PDF DVI

Region-based Memory Management in Cyclone, Dan Grossman, Greg Morrisett, Trevor Jim, Michael Hicks, Yanling Wang, and James Cheney.  ACM Conference on Programming Language Design and Implementation, Berlin, Germany, June, 2002. To appear. 
PS PDF DVI 
Cornell CS Technical Report TR2001-1856 contains the full definition and safety proof for the formal language sketched in the paper: PS PDF DVI

More information

Go to http://lists.cs.cornell.edu/mailman/listinfo/ to subscribe/unsubscribe, or click the links below to send a message (only list members may submit to Cyclone-l).

• Cyclone-l: public discussion on the Cyclone language
• Cyclone-announce-l: announcements of new code distributions
• Cyclone-bugs-l: for reporting bugs and providing comments

Credits: Cyclone is a joint project of AT&T Labs Research and Greg Morrisett's group at Cornell University; see the Acknowledgments section of the documentation for details. Here are some links to personal web pages:

Related projects: There are a number of projects with goals or techniques similar to Cyclone; we discuss some of them here.

Press: Cyclone has been of recent interest in the press. 

• Will software development get hit by a Cyclone? John Viega, Security Focus (www.securityfocus.com), December 7, 2001.
• "Cyclone" blows computer bugs out of code, Will Knight, New Scientist magazine on-line (NewScientist.com), November 16, 2001.
  This article led to a flurry of interest on Slashdot (the papers above address many of the concerns and questions posted during the discussion here).
• Secure future all at C, James Middleton, vnunet.com, November 21, 2001.
• New Cyclone Programming Language: Bugs be Gone! Mark Joseph Edwards, NT Security on-line, November 19, 2001.

Users: Cyclone currently enjoys a small user community.  Please let us know if you are using Cyclone and for what purpose so that we might add your project to our list below.

• In-kernel Network Monitoring at UPenn and AT&T
• MediaNet at Maryland and Cornell.  MediaNet is an overlay network that provides distributed streaming data services, accounting for user-specified Quality of Service criteria.  Its servers are written in Cyclone.
• The Open Kernel Environment (OKE) at the Leiden Institute of Advanced Computer Science