GCC Switches From C to C++

According to a post on the GNU Compiler Collection list, GCC is now built as a C++ program by default. This is the fruition of much effort, and the goal now is to clean up the GCC internals that are reportedly pretty type-unsafe by rewriting them using C++ classes and templates.

Comments

Compiler bootstrapping?

[Ynot_82]

How will this affect bootstrapping the GCC on bare systems?

Been a while since I've delved into LFS or the like, but I'd think GCC being C++ based would seriously complicate things as it's now got more dependencies.

libgcc and libsupc++

[tepples]

What does a distribution license have to do with a compiler?

Division support in C on some platforms (such as ARM) and exception support in C++ rely on libraries called libgcc and libsupc++. These libraries are GPLv3 with an exception. Were it not for the exception, anything compiled with the would either be GPL (because of libgcc and libsupc++) or produce a linker error (because the libraries are called and not present). The exception applies only if the compiler has not been modified to introduce non-free optimization passes performed in an independent process. See GCC Exception FAQ.

Who does believes in GPL cuties? Apple, FreeBSD, 6 year olds, anybody else?

You can add Nintendo. See the case of Pajama Sam for Wii, where Atari was willing to distribute the source code to a GPL interpreter used for the game but Nintendo didn't want GPL software on its platform.

Re:too bad GCC is not relevant anymore thanks to L

[petermgreen]

AIUI GCC is now GPLv3, the libraries it ships with are GPLv3 with exceptions that allow using them to build non-GPL programs. However they were paranoid about the idea that people would try and save gcc's internal state to disk and then run it through a propietry backend. So they crafted a complex exception that tries to forbid that while allowing most other combinations of gcc with propietry tools.

Re:too bad GCC is not relevant anymore thanks to L

[DeathToBill]

Well, let's see. I personally work with control systems using x86, MIPS, PowerPC and ARM architectures, running Linux, VxWorks, QNX and WinCE (various combinations). They all have GCC toolchains, although we admittedly don't use it for CE.

If you're thinking microcontrollers, then GCC supports AVR, 68000-series, MicroBlaze, MSP430, ARM again...

Now, personally, my refrigerator has an analog thermostat, so, technically, you are right. If it had a thermostat implemented on a CPU, then I'd think there's a very good chance it was compiled with GCC.

What exactly "programmed in GCC" might mean is left for the reader to speculate on.

Re:RTFA

[Joce640k]

Yeah. I'm not a fan of C++, though the compiler spends so little time running that this shouldn't pose much of a problem with bloat and clunk. On the other hand, loading C++ stuff is an abomination that takes eternity due to massive mangling (a problem Michael Meeks has spent a lot of time trying to marginalize with Bdirect linking, faster hash algorithms, etc), and the compiler gets run repeatedly.

I'm not sure mangling is really as much of a problem people make it out to be. It *did* cause problems trying to mix binaries from different compilers but I don't think it was ever really a performance problem. If linking is slower it's because the programs are larger.

OTOH name mangling is a massive benefit to programmers. Writing big programs is a huge pain in the butt if every single function/variable has to have a unique name. Namespaces are one of the reasons C++ programs scale so much better then C programs.

An observation of "procedural" coders

[GodfatherofSoul]

I've never understood the hostility towards OOP. I've always seen it as nothing more than another great tool to use, but so many posters act as if OOP is some false god brainwashing the masses. My theory is they're taking the act of embracing OOP as synonymous with insulting C.

Look at the added java.io.PrintStream.printf() method that uses a variable argument list. Someone had to be a special kind of asshole to adulterate a strongly-typed OO-language with that bullshit when the obvious OO solution is an array for a second argument. That's the kind of modification made when someone is making a political point, not a design improvement.

Re: progress

[Greyfox]

I hadn't really looked at it much through the course of my career -- most of my employers wanted C or Java, not C++. Having only recently started with it, I'm finding it to be about as sharp a weapon as C, but with the ability to be far more type safe. It really isn't that difficult to get a grasp on it. You just need to understand its pass-by rules, which are moderately more complex than Java's. You also need to be able to understand the STL and use it effectively. You also need some object oriented design experience if you're doing your own design work.

The third party libraries for it are pretty nice these days, too. I'd rather do threading in C++ with boost::thread than in Java. I've found boost::regex and boost::program_options to be a joy to work with as well. Eigen is also very nice if you need a math library.

Overall I've been quite enjoying working with it. It's not nearly as intimidating as it first appears, and the stuff you really need to know about it is pretty simple and easy to learn.