I recently heard a google employee come speak at my university about how google's main codebase is compiled using clang, and their janitorial work is done using clang mapreduce [1]. Furthermore, that google employee talked about how google is working with the LLVM team to integrate the toolchain into visual studio for cross-platform compilation [2]. Pretty cool stuff!

[1] (similar talk) https://www.youtube.com/watch?v=mVbDzTM21BQ

[2] http://llvm.org/docs/GettingStartedVS.html

" google is working with the LLVM team to integrate the toolchain into visual studio "

the 3 giants are working together...

GCC has support for plugins since version 4.5, which is over four years old. Also, the error messages have improved greatly in the last releases.

You really want to have the infrastructure argument about which is a better compiler infrastructure?

Even GCC developers (like I was ) don't really question it.

The only thing GCC buys you right now, at all, is slightly better performance (it varies depending on your benchmark) and support for a larger variety of odd embedded systems.

On the other hand, LLVM is very easy to modify, can be built as a library (as can clang), has a sane, well defined IR, etc.

Did I say that gcc has the better infrastructure, the more modern code base, better modularity? I don't think so. That would actually be pretty weird, given that its code base is nearing 30 years of history. But I hope that it is still allowed to say that GCC has made progress the past few years. And I think it is worth refuting claims like "you cannot access the AST in gcc", since this is simply not true anymore. Yes, actually dealing with the AST is baroque, but you can access it nonetheless. There are nice plugins for GCC, like Melt or the python-plugin which make this easier, though. Also, there's the license/freedom thingy, which might not interest you, but others do care about such things.

"Did I say that gcc has the better infrastructure, the more modern code base, better modularity? I don't think so. "

Your reply certainly implied you thought GCC was fine along the same axises your parent said clang was better.

"But I hope that it is still allowed to say that GCC has made progress the past few years." You are talking to a guy who helped make some of this progress (for example, I helped build the tree-ssa project that brought a language independent middle IR and SSA optimizers to GCC). It's certainly made progress, but that progress had been fought about for the 5 years before that. At the same time, GCC lost good developers during these fights due to wanting to get stuff done and not deal with politics.

"Also, there's the license/freedom thingy, which might not interest you, but others do care about such things."

Actually, it interests me immensely. I helped with things like the libstdc++ exception, etc. Besides being a compiler guy, i'm an open source lawyer.

But in the end, I choose stuff based on technical merits first, freedom second. You are of course, welcome to do as you please.

> Your reply certainly implied you thought GCC was fine along the same axises your parent said clang was better.

No. I simply corrected a false statement regarding gcc. I did not compare it to clang at all. I have no illusions how gcc does compare to clang w.r.t. to code quality, modularity, etc. As I've said: it would be weird if it were otherwise. It's really not hard to beat gcc in that area.

> You are talking to a guy who helped make some of this progress

Thank you (no irony intended).

> Actually, it interests me immensely.

It may interest you, but as you say yourself:

> But in the end, I choose stuff based on technical merits first, freedom second

>You are of course, welcome to do as you please.

Will do, thanks.

> Besides being a compiler guy, i'm an open source lawyer.

Apologies for replying in-thread (I couldn't find contact in your profile). Would it be possible to ask you a few questions about a perhaps-novel compiler licensing question for an open source application we're developing (we're a commercial entity and can pay for your time)? If so you can reach me at the email in my profile.

If you spend a long time damaging your project's internal organization, expect to spend a long time digging back out.

Clang brought new life into C and C++ eco-systems, specially in the sense that since we cannot get rid of C for the time being, at least we can improve the tooling around it to make it safer.

But sometimes I wonder if the license doesn't play a role as well.

Why would you want to get rid of C?

To make certain classes of bugs impossible. What will end up hapenning with all code that must be kept is that ever stricter compilers and static analyzers will find the unsafe code and it will be fixed piece by piece.

The license played no role in this switch :)

I have no idea whether it's true, but on the topic of gcc's inferiority in the matter of error messages, this source claims it's no longer true: https://gcc.gnu.org/wiki/ClangDiagnosticsComparison

Of course, given the source, apply salt :-).

I dont know about C++, but for C Clang certainly feels like it has better error messages than the variant of GCC that the distro the Uni defaults to has, If nothing else, because of the colour.

Are the versions you're using up to date, however?

None of these reasons matter at all for production builds. The production build needs to happen only once per release, and the only things that count are performance and reliability.

The last time I checked gcc still had better performance than CLang, but things might have changed since then.

You don't want to build your nightlies with one compiler and then switch to a different one just for the final release.

1. It depends on your benchmarks. There are some it's behind on, some it's ahead on.

2. LLVM is a lot easier to improve.