[LarrySDonald]

It does sound like a bit of a strange assertion. gcc is amazingly core to so much and (in this case importantly) so much commercial. Not even the linux kernel itself has this many things that need it to be continued.

Could it be ousted? Sure, if a gnu (or otherwise foss) competitor steps up and does it better (good luck..) but in that case, no problem. Could it be that the gnu/linux distributions and applications running the majority of the internet will have to rely on a proprietary compiler or die? That's just wildin' - issues aside that's nothing even any of the major corporations could really suggest.

[eropple]

if a gnu (or otherwise foss) competitor steps up and does it better (good luck..)

There is a pretty compelling argument that LLVM and Clang are doing precisely that. And the "toolability" referred to in the article is a big part of that. Clang complete[1] is an example of using Clang to do things that the GNU toolchain thinks are perfectly doable with a box of regex. (Spoilers: they're so not.)

[1] - http://www.vim.org/scripts/script.php?script_id=3302

[hosay123]

It would take an immensely ballsy release engineer to approve switching from GCC to clang even for a modestly sized, mature codebase. I can think of at least two Fortune 500s where this will almost certainly never happen: the potential cost incurred by the change would far outweigh just hiring a team to keep the old compiler alive, at least in the medium term.

[Scaevolus]

Google and Apple already have.

Switching compilers isn't that difficult, especially when they're as reliable as GCC and Clang.

[barkingcat]

Freebsd has switched over to clang - and that os is used as the basis for many types of embedded devices such as network routers.

[gillianseed]

FreeBSD has had a long outspoken goal of not relying on GPL in the base system, an ideological choice. The transition to clang/llvm has also been very long and will (if everything goes as planned) be finalized in FreeBSD 10.

https://wiki.freebsd.org/GPLinBase

Apple (as they would not accept GPLv3) was stuck with shipping the very old GCC 4.2.1, also Apple wanted to be able to incorporate the compiler toolchain into their proprietary solutions like XCode, something GPL obviously won't allow. Hence funding LLVM while starting work on Clang made sense for them, but again not a choice made (purely) on technological merits.

[vor_]

> Hence funding LLVM while starting work on Clang made sense for them, but again not a choice made (purely) on technological merits.

I think it's inaccurate to portray the move away from GCC as simply political with happy side effects, though avoiding the GPL3 was certainly a prime motivation. Greg Parker has stated on Apple developer mailing lists that the adoption of Clang/LLVM has allowed them to rapidly improve the Objective-C language, and that there are more Apple employees working on the language and compiler today than 10 years ago.

[alperakgun]

as far as i understand freebsd is there just because some license fanatics want to maintain a commercial-izable alternative to linux. they switching to clang doesn't mean much, because it is most probably a dogmatic, ideological move.

[X-Istence]

I at one point suggested it was the license as well, but cpercival at the time corrected me:

http://news.ycombinator.com/item?id=1351634

[icebraining]

Please stop with the accusations of dogmatism. Regardless of whether you agree with their goals or not, the reasons behind avoiding GPLv3 licensed components are very pragmatic.

[belorn]

The common myths and fear about GPLv3 are far from pragmatic.

I can understand those that only want permissive licensed software for components. This make sense, as otherwise the copyright license will put some requirements when distributing copies of the new work. If its proprietary components, you got to buy a license. If its copyleft components, you got to use a particular license.

But if we are talking about gplv2 vs gplv3, only a very small subset of people will ever have to care about the differences between those two licenses. It actually only comes down to two questions.

1: Are you planning to sell a product, but want to keep root access to the device after its being sold, while at the same time directly preventing giving the same access to the new owner who bought your device?

2: Are you in a patent license agreement with an other company over patents you pay for and which cover aspect of the new product?

If your answer is No and No, to those two questions, you can regard GPLv2 and GPLv3 as identical licenses. Its that simple.

[viraptor]

There's also an issue of code contribution that some people will not experience or know about. I'm working at a large company and I can contribute to any FOSS project... unless it's gpl3 or requires a copyright assignment. In that case I have to go via a review process taking weeks to complete and involving 2 levels of management. Or I can simply fork locally, patch and never contribute back (this happens almost every time).

I doubt this is rare inside of large corporations.

[sirclueless]

#2 in particular seems impossible to ensure. There's no way to say "No" with any confidence. If you make a product, and someone comes to you with a patent claim asking for money, you put yourself in the position of completely rewriting your project or taking the claim all the way to court on merit. Violating a patent does not require intent, so unless you have intimate knowledge of every possible patent claim that could be made, and you are willing to fight all of them all of the way, you might as well start right off the bat without GPLv3.

[vor_]

An ironic statement considering the backstory behind GCC's obfuscation and complexity.

[bzbarsky]

It really depends on the code.

Mozilla switched its Mac builds from gcc 4.2 (or rather the Apple fork of it) to clang, because the cost of doing the switch was lower than the cost of avoiding all the bugs in said fork of gcc 4.2 that didn't exist in the other three compilers the codebase also had to compile with (gcc 4.4 on Linux and MSVC).

[X-Istence]

FreeBSD is making the change, most of the code for the company I work for is only compiled with clang ... we do government work.

[Hello71]

You mean like FreeBSD?

[cpeterso]

Mozilla switched from gcc to clang on Mac OS X (starting with Firefox 17 last year):

https://groups.google.com/forum/#!topic/mozilla.dev.platform...

[taligent]

I'm confused but didn't Apple just do this for two operating systems.

And then moved their entire OSX and iOS development community as well ?

[hosay123]

Apple manufacture consumer entertainment devices that are neither safety critical in nature nor difficult to field test. Think more along the lines of Boeing, Northrop Grumman or Raytheon.

[cwzwarich]

There is a whole industry of people providing operating systems and compilers for high assurance embedded development, led by companies like Green Hill Software. Nobody would ship a safety critical embedded project using either GCC or Clang.

At the highest levels of safety, the DO-178B standard for aviations systems requires compilers to generate code in a way that has a fixed structural relationship between source and output patterns, where each pattern is independently verified, so that every output instruction is directly traceable to a source instruction. All other code generated by the compiler has to be manually verified. This eliminates the use of most of the optimization techniques found in modern compilers. Also, the emphasis on Worst-Case Execution Time (WCET) verification means that performance improvements only matter if your WCET estimates can incorporate them.

[orionblastar]

Back in 1996-1997 I was a federal contractor working as a software consultant and analyst using several different systems for logistics and provisioning for the US Army to downsize a base to a different state.

We used different operating systems and different databases and programming languages to create a redundant system that solved the same problem or generated the same report. We would have at least three programs running with three different technologies and if the reports were all the same, the system was in good shape, but if one of the reports differed somehow we knew we had to check and fix something.

We did use SunOS/Solaris, HPUX, Linux (Slakware IIRC), DOS/Windows 3.0, Windows 95, Windows NT, etc. In some cases there were C programs using the native C compiler with whatever Unix system that was in use, and in the case of Windows or DOS we used whatever language or software was available. I worked in Clipper, DBase, Oracle PL/SQL, SQL Server, MS-Access, and sometimes even flat text files downloaded from mainframes or FTP sites on the Military network that needed converting to different databases. As a federal contractor I was limited in what I could do, for example my PC did not have a CD drive and they would not allow ODBC drivers to be installed. I did not have administrative access but instead access to a maintenance account that others shared to work with databases that was limited in many ways.

My point is you work with whatever they give you to work with, you may be limited in what you do, but you use what you have available. So yes you might be limited to GCC on a Linux system and no root access to install CLANG or LLVM.

[csense]

> PC did not have a CD drive

Was this before or after Bradley Manning? (I think he used a CD-RW drive on a "secure" computer to extract the data he sent to Wikileaks.)

> account that others shared

Shared account? Really? Sounds like top-notch security in action. [/sarcasm]

> no root access to install CLANG or LLVM

You don't need root access, you can just do:

./configure --prefix=$HOME/clang

or whatever the equivalent is if clang uses a different build system.

If /home is mounted noexec, that's a real problem, but if you're doing software development, noexec would mean you couldn't run the programs you're writing either.

Of course, just because there's no technical reason you can't do something, doesn't mean there isn't a nontechnical / political reason you shouldn't. If you'd made a project change as large as using a different compiler without approval from (or at least notification to) higher up, you might have gotten in trouble.

[iso-8859-1]

You don't need root to install Clang/LLVM.

[plafl]

Actually VxWorks uses gcc (and make for the build system). At level A I think you are required that your tests have 100% coverage, at machine instruction level, but I don't remember there must be that kind of fixed relationship between source code and output from the compiler. I have developed only for level B and have never been involved in toolchain verification, so maybe there is something I am missing.

[foobarqux]

> Nobody would ship a safety critical embedded project using either GCC or Clang.

They would and they do.

I'm not sure what the second paragraph is trying to say. GCC (and Clang) optimizations can be turned off selectively or entirely altogether.

DO-178B doesn't prohibit optimizations in general.

[tjr]

I was writing some networking code for an avionics project in C, and stumbled upon a bug in GCC that was causing structures to be packed incorrectly in memory. The bug had long been fixed in newer versions of GCC, but it's so time-consuming and money-consuming to approve new compilers for avionics use that we just had to work around the bug.

If upgrading from one version of GCC to another is a big deal, I can only imagine how excited avionics stakeholders wouldn't be to switch compilers altogether.

It may happen eventually, but then again... it may not. Just so long as they are happy to use some GCC build from 2002 or whatever, and just so long as there's no pressing need to use something else, why should they take on the effort and expense of switching?

[wooster]

I'd be surprised and disappointed if those companies were using GCC to compile avionics code written in C++.

[0x0]

Really, why? What should they have been using - at least just a few years ago before LLVM became mainstream?

[frisco]

Probably icc (Intel's C++ compiler), MSVC++, or one of IBM's (i.e., xlcc).

[wooster]

cwzwarich's comment above covers it pretty well.

[gillianseed]

What else do you propose they should be using?

[jfb]

Does your back hurt from moving those goalposts?

[hosay123]

Are you objecting to the removal of "overpriced" (irrelevant opinion) or the addition of specific examples?

[jfb]

You made a claim ("It would take an immensely ballsy release engineer to approve switching from GCC to clang even for a modestly sized, mature codebase"); people pointed out counter-examples (Apple and Google); you move the goalposts. Would it have killed you to admit that you were wrong in the post as written?