19 ms·

Why is everyone itching to get off of GCC? Or is it all just posturing, to get GCC to work harder now that it has competition?

by lhnn 15y ago

getsat 15y ago
GCC is becoming larger and more unmaintainable with each release. Competition in this space has been pretty sorely lacking for quite some time. The OpenBSD folks are also pushing PCC as a GCC alternative. It'll be nice to have a BSD-licenced GCC equivalent for distribution with FreeBSD/OpenBSD, too. Clang also has REALLY great error messages compared to GCC. It will tell you exactly where you forgot a comma, semicolon, quote, etc. instead of randomly pointing to some line around the error in question.
- cliffbean 15y ago
  It is useful to keep in mind a common confusion. Apple and various BSD's stopped updating GCC around version 4.2, the last GPLv2 version, which is approximately 4 years old now. For people who only develop on those platforms, this is what "GCC" means. So when someone from Apple or someone with an obvious BSD bias talks about how much better clang is than "GCC", they're usually talking about how much better clang is than an old unmaintained version of GCC. clang does have strengths, but when we make comparisons, we should be clear about what it is we're comparing.
  - nknight 15y ago
    Unless there's been a concerted effort in the last ~year or so to improve GCC's error messages and compilation speed, clang's primary technical strengths remain unchanged relative to GCC. Saying we're comparing old versions isn't really useful unless the new versions have actually addressed the relevant issues.
    - cliffbean 15y ago
      Recent versions of GCC do, in fact, have improved error messages. For example, GCC 4.6 fixed a problem that the post I was replying to mentioned, where a missing semicolon after a struct definition would cause GCC to elicit an error message pointing to some other nearby line. If you're comparing clang to just GCC 4.2, then say that. If you've compared it with recent versions of GCC too, then say that.
      - adbge 15y ago
        $ gcc -v ... gcc version 4.6.2 20120120 (prerelease) (GCC) When it comes to diagnostics, GCC isn't even competitive.
- gillianseed 15y ago
  Well Clang/LLVM is also becoming larger with each release. As for GCC becoming more 'unmaintainable', can you point me to anything supporting that notion? It's certainly not unmaintainable now as proven by them regularly releasing new improved versions which serve as the de facto compiler toolchain for open source systems. Also when speaking of GCC and how old and full of cruft it is, you need to realize that it's code base is being continously improved with each new release with a strong focus on modularity. It's not the same codebase as it was back in 1987. I'm very happy Clang/LLVM exists and progressing at a great pace as I see increased availability of open source compiler toolchains as something awesome. Also LLVM really does have some great features like the best-in-class error reporting and it also serves an undeniable purpose as a jit framework for numerous projects. That said I don't understand those trying to push the idea of GCC being obsolete (unless they are nurturing some political/licence based crusade) as it's a very mature compiler toolchain targeting a large number of architectures and (atleast for me) quite importantly generating faster code than Clang/LLVM. Also the notion that companies would be afraid of GCC strikes me as odd given that we have Red Hat, IBM, Google, CodeSourcery, Suse etc employing full-time GCC developers. I hope to see these compiler toolchains continously going neck to neck in the future and thus provide the open source ecosystem with two first class options each with their respective strenghts.
  - Someone 15y ago
    "the notion that companies would be afraid of GCC strikes me as odd given that we have Red Hat, IBM, Google, CodeSourcery, Suse etc employing full-time GCC developers." Afraid? I expect that these companies have spent serious money on lawyers to figure out whether GPL 3 was acceptable for them before committing to it. Also, Mac OS supports OpenCL (http://en.wikipedia.org/wiki/OpenCL http://en.wikipedia.org/wiki/OpenCL). One could argue that that makes the compiler more a part of the OS than "just another application that runs on it". If they used GPL code there, a perceived risk could be that they could be forced to make their OS GPL.
falling 15y ago
sane error messages are worth the switch alone.
nas 15y ago
Even if everyone doesn't switch, having more than one widely used open-source C compiler would be healthy. If anything, it allows some non-portable code to be found and fixed. Also, competition is healthy. The different compiler developers can choose to focus on specific areas of improvement (e.g. compile speed vs executable speed) rather than a one-size-fits-all approach.
- gillianseed 15y ago
  Fully agreed, having two open source, free compiler toolchains with which you can fully build your software stack beats having to rely on just one. And like you said competition is always good. Of course that is why it's better if both compilers continue to flourish, which is what I'm hoping/expecting will be the case.
lambda 15y ago
This kind of work is valuable even without getting rid of GCC. Each compiler has a slightly different implementation of warnings; getting the code to compile under two compilers can find issues that you wouldn't find under just one compiler. It also increases flexibility for developers. Perhaps I prefer to use Clang for its better error messages, or because I find it easier to target at a new platform that I'm working on. If the code already runs under Clang, then that's work I don't have to do. Clang can also be used as an independent parser more easily for GCC, so tools that use it to generate code browsing information or the like benefit from the code already being parseable with Clang. Compiling under another compiler will also catch more of the cases in which you're depending on non-portable behavior or extensions, which increases the likelihood that you will be able to run it under static analyzers like Coverity, Clang Analyzer, Klee, Splint, or the like. Basically, beyond wanting to move away from GCC, there is real value in putting work into making sure that everything compiles under another compiler. It's like making sure your web site works on multiple browsers; it can help you catch errors earlier, allow people to use better debugging tools, widen your audience, and help future-proof you. Now, there are some people who are itching to get away from GCC. For one thing, it is a bigger, older, wartier project, that is harder to work with. People find Clang and LLVM more modular and extensible. For another, there are some companies that are deathly afraid of the GPLv3, and won't touch anything to do with it (Apple in particular, as well as some other embedded device manufacturers I believe). But there are many reasons for wanting to make sure that your software compiles under Clang, and not all of them mean that you want to ditch GCC, just that Clang provides additional value as well.

Why is everyone itching to get off of GCC? Or is it all just posturing, to get GCC to work harder now that it has competition?

by lhnn 15y ago

Why is everyone itching to get off of GCC? Or is it all just posturing, to get GCC to work harder now that it has competition?

getsat 15y ago

GCC is becoming larger and more unmaintainable with each release. Competition in this space has been pretty sorely lacking for quite some time. The OpenBSD folks are also pushing PCC as a GCC alternative. It'll be nice to have a BSD-licenced GCC equivalent for distribution with FreeBSD/OpenBSD, too. Clang also has REALLY great error messages compared to GCC. It will tell you exactly where you forgot a comma, semicolon, quote, etc. instead of randomly pointing to some line around the error in question.

cliffbean 15y ago
It is useful to keep in mind a common confusion. Apple and various BSD's stopped updating GCC around version 4.2, the last GPLv2 version, which is approximately 4 years old now. For people who only develop on those platforms, this is what "GCC" means. So when someone from Apple or someone with an obvious BSD bias talks about how much better clang is than "GCC", they're usually talking about how much better clang is than an old unmaintained version of GCC. clang does have strengths, but when we make comparisons, we should be clear about what it is we're comparing.
- nknight 15y ago
  Unless there's been a concerted effort in the last ~year or so to improve GCC's error messages and compilation speed, clang's primary technical strengths remain unchanged relative to GCC. Saying we're comparing old versions isn't really useful unless the new versions have actually addressed the relevant issues.
  - cliffbean 15y ago
    Recent versions of GCC do, in fact, have improved error messages. For example, GCC 4.6 fixed a problem that the post I was replying to mentioned, where a missing semicolon after a struct definition would cause GCC to elicit an error message pointing to some other nearby line. If you're comparing clang to just GCC 4.2, then say that. If you've compared it with recent versions of GCC too, then say that.
    - adbge 15y ago
      $ gcc -v ... gcc version 4.6.2 20120120 (prerelease) (GCC) When it comes to diagnostics, GCC isn't even competitive.
gillianseed 15y ago
Well Clang/LLVM is also becoming larger with each release. As for GCC becoming more 'unmaintainable', can you point me to anything supporting that notion? It's certainly not unmaintainable now as proven by them regularly releasing new improved versions which serve as the de facto compiler toolchain for open source systems. Also when speaking of GCC and how old and full of cruft it is, you need to realize that it's code base is being continously improved with each new release with a strong focus on modularity. It's not the same codebase as it was back in 1987. I'm very happy Clang/LLVM exists and progressing at a great pace as I see increased availability of open source compiler toolchains as something awesome. Also LLVM really does have some great features like the best-in-class error reporting and it also serves an undeniable purpose as a jit framework for numerous projects. That said I don't understand those trying to push the idea of GCC being obsolete (unless they are nurturing some political/licence based crusade) as it's a very mature compiler toolchain targeting a large number of architectures and (atleast for me) quite importantly generating faster code than Clang/LLVM. Also the notion that companies would be afraid of GCC strikes me as odd given that we have Red Hat, IBM, Google, CodeSourcery, Suse etc employing full-time GCC developers. I hope to see these compiler toolchains continously going neck to neck in the future and thus provide the open source ecosystem with two first class options each with their respective strenghts.
- Someone 15y ago
  "the notion that companies would be afraid of GCC strikes me as odd given that we have Red Hat, IBM, Google, CodeSourcery, Suse etc employing full-time GCC developers." Afraid? I expect that these companies have spent serious money on lawyers to figure out whether GPL 3 was acceptable for them before committing to it. Also, Mac OS supports OpenCL (http://en.wikipedia.org/wiki/OpenCL http://en.wikipedia.org/wiki/OpenCL). One could argue that that makes the compiler more a part of the OS than "just another application that runs on it". If they used GPL code there, a perceived risk could be that they could be forced to make their OS GPL.

falling 15y ago

sane error messages are worth the switch alone.

nas 15y ago

Even if everyone doesn't switch, having more than one widely used open-source C compiler would be healthy. If anything, it allows some non-portable code to be found and fixed. Also, competition is healthy. The different compiler developers can choose to focus on specific areas of improvement (e.g. compile speed vs executable speed) rather than a one-size-fits-all approach.

gillianseed 15y ago
Fully agreed, having two open source, free compiler toolchains with which you can fully build your software stack beats having to rely on just one. And like you said competition is always good. Of course that is why it's better if both compilers continue to flourish, which is what I'm hoping/expecting will be the case.

lambda 15y ago

This kind of work is valuable even without getting rid of GCC. Each compiler has a slightly different implementation of warnings; getting the code to compile under two compilers can find issues that you wouldn't find under just one compiler. It also increases flexibility for developers. Perhaps I prefer to use Clang for its better error messages, or because I find it easier to target at a new platform that I'm working on. If the code already runs under Clang, then that's work I don't have to do. Clang can also be used as an independent parser more easily for GCC, so tools that use it to generate code browsing information or the like benefit from the code already being parseable with Clang. Compiling under another compiler will also catch more of the cases in which you're depending on non-portable behavior or extensions, which increases the likelihood that you will be able to run it under static analyzers like Coverity, Clang Analyzer, Klee, Splint, or the like. Basically, beyond wanting to move away from GCC, there is real value in putting work into making sure that everything compiles under another compiler. It's like making sure your web site works on multiple browsers; it can help you catch errors earlier, allow people to use better debugging tools, widen your audience, and help future-proof you. Now, there are some people who are itching to get away from GCC. For one thing, it is a bigger, older, wartier project, that is harder to work with. People find Clang and LLVM more modular and extensible. For another, there are some companies that are deathly afraid of the GPLv3, and won't touch anything to do with it (Apple in particular, as well as some other embedded device manufacturers I believe). But there are many reasons for wanting to make sure that your software compiles under Clang, and not all of them mean that you want to ditch GCC, just that Clang provides additional value as well.