Portable C Compiler

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Portable C Compiler
Latest release	0.9.9 / January 27, 2008 (2008-01-27); 137 days ago
Written in	C
OS	Unix-like
Genre	C Compiler
License	BSD License
Website	http://pcc.ludd.ltu.se/

The Portable C Compiler (also known as pcc or sometimes pccm - portable C compiler machine) was an early compiler for the C programming language written by Stephen C. Johnson of Bell Labs^[1] in mid-1970s—based in part on ideas from earlier work by Alan Snyder in 1973.^[2]^[3]

One of the first compilers that could easily be adapted to output code for different computer architectures, the compiler had a long life span. It shipped with BSD Unix until the release of 4.4BSD in 1994—which replaced it with the GNU C Compiler. It was very influential in its day, so much so that at the beginning of the 1980s, the majority of C compilers were based on it.^[4]

1 Features
2 Current version
3 References
4 See also
5 External links

[edit] Features

The keys to the success of pcc were its portability and improved diagnostic capabilities:

The compiler was designed so that only a few of its source files were machine-dependent.
It was relatively robust to syntax errors and performed more thorough validity checks.

The first C compiler, written by Dennis Ritchie, had used a recursive descent parser, incorporated specific knowledge about the PDP-11, and relied on an optional machine-specific optimizer to improve the assembly-language code it had generated. In contrast, Johnson's "pcc" was based on a yacc parser generator and used a more general target machine model. Both compilers produced target-specific assembly language code, which they then assembled to produce linkable object modules.

[edit] Current version

A new version of pcc based on the original by S. C. Johnson is now maintained by Anders Magnusson. The compiler is provided under the BSD license. According to Magnusson:

“

…The big benefit of it (apart from that it's BSD licensed, for license geeks) is that it is fast, 5-10 times faster than gcc, while still producing reasonable code …it is also quite simple to port… ^[5]

”

This new version was added to the NetBSD pkgsrc and OpenBSD source trees in September 2007,^[6] and later into the main NetBSD source tree,^[7] and there has been some speculation that it might eventually be used to supplant the GNU C Compiler on BSD-based operating systems.^[8]