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GCC Compiler Finally Supplanted by PCC?
Sunnz writes "The leaner, lighter, faster, and most importantly, BSD Licensed, Compiler PCC has been imported into OpenBSD's CVS and NetBSD's pkgsrc. The compiler is based on the original Portable C Compiler by S. C. Johnson, written in the late 70's. Even though much of the compiler has been rewritten, some of the basics still remain. It is currently not bug-free, but it compiles on x86 platform, and work is being done on it to take on GCC's job."
I notice that TFS doesn't say that anyone is actually able to compile anything (other than PCC) with it. The BSD folks would love to have a BSD-licensed drop-in replacement for GCC; but it doesn't sound like this is it. Not yet at least.
./build.sh or whatever).
Wake me up when you're able to use PCC instead of GCC to do a 'make world' (or
pcc will take YEARS to get the functionality and optimizations that gcc has. Even if it compiles slowly and sometimes generates dumb code.
Either way, they'd much, much better off if they imported LLVM and redirected their compiler brain power to clang.
PCC is interesting, but it's based on technology from the 70's, doesn't support a lot of interesting architectures, and has no optimizer to speak of.
If you're interested in advanced compiler technology, check out LLVM, which is an ground up redesign of an optimizer and retargettable code generator. LLVM supports interprocedural cross-file optimizations, can be used for jit compilation (or not, at your choice) and has many other capabilities. The LLVM optimizer/code generator can already beat the performance of GCC compiled code in many cases, sometimes substantially.
For front-ends, LLVM supports two major ones for C family of languages: 1) llvm-gcc, which uses the GCC front-end to compile C/C++/ObjC code. This gives LLVM full compatibility with a broad range of crazy GNU extensions as well as full support for C++ and ObjC. 2) clang, which is a ground-up rewrite of a C/ObjC frontend (C++ will come later) that provides many advantages over GCC, including dramatically faster compilation and better warning/error information.
While LLVM is technologically ahead of both PCC and GCC, the biggest thing it has going is both size of community and the commercial contributors that are sponsoring work on the project.
-Chris
It has less to do with the license and more to do with GCC's increasingly spotty support for some of the hardware platforms that NetBSD and OpenBSD run on. That and GCC internals are a maintenance nightmare, and its development process is getting even less commmunity-driven than it was before (which was never that much). Asking for a new compiler warning might take anywhere from a day to years just to get a response. The license is definitely gravy though.
The BSD license that PCC is under, I understand, is actually a problem even to the BSD folks: PCC is actually extremely old (it was originally written for the PDP11!) and apparently it still carries the advertising clause.
I believe it was de Raadt that once mentioned he'd prefer a non-optimizing compiler that produced simple, bullet-proof, bug-free code, i.e., in terms of the OS and its base tools, he prefers correct to fast.
Well that explains a lot. And here I was thinking that all modern compilers were designed correctly with a front-end and back-end. So much for academics.
Actually, the post you're replying to is total bollocks. GCC has had a clear divide between front and back end (not to mention a source-language independent middle layer for performing optimizations) since I first looked at it in about 1996. Each layer is hideously complex, but they are all there.
Auctually if I could write in C as well as him, I would do so more often. The problem is not him writing in C, its other people writing in C that are not as good as him. Do to the scope of his work, him writing in C does not lead to more bad C being written. So I'm auctually thankful he is coding in C.
That being said, he should encourage lesser programmers (including myself) to specifically not code in C.
--- Justin Dearing http://www.justaprogrammer.net/ We're just programmers.
You couldn't have gotten that statement any MORE WRONG if you had tried.
GCC's "production quality" is an on-again, off-again thing. Through most of v3.x it had too many bugs to count, and was inherently unreliable. It couldn't even compile ITSELF with the most basic optimizations or the resulting binary would generate incorrect code. Up until v4 it also misaligned stack variable. It had, and still has, MANY bugs. That GCC successfully compiles code at all is almost entirely due to it being so popular that everyone knows it, and works around its bugs without even thinking about it.
It has never had GOOD support for any other platforms than x86. Remember the RedHat GCC2.96 fiasco? They forked it because they needed it to support more platforms than it currently did. And even through v3.x the non-x86 ports of GCC had even more bugs than on x86, commonly falling apart if you attempt to use any optimizations. Now, they're DROPPING support for those platform entirely, which is a big problem for developers of operating systems for those platforms.
"Improved" is pretty vague. HURD has probably been "improved" for every minute of it's existence as well... Meanwhile the far younger ICC (Intel's compiler) beats the pants off of GCC without even trying.
What's more, GCC's "improvements" come at great cost. If you're a full-time developer, for the final release you want optimized code, but while developing, you want to compile and be able to test code frequently, and so as quickly as humanly possible. GCCv3+, even with all optimizations disabled, takes far, far longer to compile binaries than even older versions of GCC, and as it says, something like 10X slower than PCC.
The license issue is only incidental. These (and other) problems pushed them away from using GCC. Since they happen to be BSD developers, they'd prefer their work to be BSD licensed, and so it is.
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