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Can you name a C++ compiler?
C++ is arguably the best primary language available today for non web based applications that are large, complicated, and advanced. But what should one use to compile their C++ code? Can you even name a single C++ compiler?C++ was created by Bjarne Stroustrup in 1983 at AT&T. But instead of making a compiler for it, they opted to make a C++ to C translator and dubbed it Cfront. In 1985, Bjarne Stroustrup released a book on his language, moving the language onto center stage. But still there was no compiler to be found, only a translator.
Now translators aren't so bad. After all, they give the programmer many additional features over the base language, such as new types, operators, and other goodies. These extras make it easier to breathe in the art of programming. In fact, there exist many preprocessors and language extensions today using translators to make life easier. Qt for example brings their own C++ extensions to the table such as "slot functions" which works with a preprocessor, translating code to pure C++ and adding any extra functions and data as needed. Now for minor additions, or for translators to C++ which deal with clearly defined objects, generated C++ code is pretty good. But when dealing with entirely new constructs added to a language, generated code can be very bad depending on the circumstance it's in, or not be as optimized as it could be if the compiler understood which high level constructs the code is coming from.
For these reasons, having a real compiler is better than a translator. But what was the first actual compiler for C++? It might come as a surprise to some, but the first C++ compiler was actually GCC, in 1987, 2 years after C++ was exposed to the world. However what C++ itself was - was determined by each new version of Cfront, and GCC did what it could to produce identical results (with extra features on top of course). Over time other C++ compilers came out, each bringing its own slew of extra features to the table, and some of them even acting differently than Cfront did.
In 1992, Microsoft's Visual C++ was released, and it understood code quite a bit differently than Cfront, causing many compatibility issues, and earning a new meaning to MSVC++ - Microsoft Vs. C++. Adding to these compatibility problems was many new features being proposed all the time such as templates, and Cfront development (the de facto standard) stopping in 1993, as it was deemed impossible to keep building upon a translation framework for such a complicated language. Since there was so many different implementations out there, and the "standard" one decided to throw in the towel, the International Organization for Standardization (ISO) decided to step in and standardize C++ as it did with C in 1989.
The ISO finished the standardization of C++ in 1997, and published the new specification in 1998. From this point on, the only real C++ is the one standardized in 1998 (although a second standard of C++ is being worked on to be completed in the next few years), and nothing else can be accurately labeled C++. So now we're about a decade later, guess how many C++ compilers there are?
And the correct answer to the above question is none! If you want to turn to GCC, it still doesn't support the "export" keyword, nor does it handle certain complicated classes entirely right. If you turn to MSVC, until very recently, their implementation of the Standard Template Library was quite shoddy, and was pretty bad with templates in general. More recent MSVCs still have issues though, see here for a short list from Microsoft itself. Aside from Microsoft's list, I'm told by some that they also found some other issues that aren't listed. And for some strange reason, MSVC doesn't even handle scope properly by default for variables created in headers to a block, and instead has an option to enable proper scoping separately. Whose bright idea was it to make improper scoping the default?
So if you want to write a real C++ program today, what exactly should you use? Well, lucky for us, Edison Design Group decided to do what AT&T deemed impossible, and make an up to date fully standards compliant C++ to C translator. Although EDG themselves don't distribute it to the general market. If you want to be able to build your C and C++ code properly, currently, your only choice is to find a complete setup around EDG's translator, such as Comeau C/C++.
Drawbacks with Comeau C/C++ though is that it isn't free. GCC is free, and Microsoft now also offers free versions of their C/C++ compiler, while Comeau C/C++ costs $50 per platform. Comeau C/C++ also isn't as portable as GCC, and doesn't operate properly on a fraction of the OSs that GCC does. Being a translator, it also suffers from the less optimal code generation issues, not to mention longer build times due to more memory usage and more steps involved. Comeau C/C++ also doesn't work by itself, but on install has to configure itself on top of an existing compiler already installed such as GCC or MSVC.
Scary how we don't even have a compiler for the first standardization of C++ and they're already working on a second standardization. C also had a second standardization done in 1999, but is mostly supported by GCC, and will probably be fully supported soon enough. C99 of course is also supported by Comeau C/C++ and works by translating C99 to C89 as needed.
Although the important question we have to ask is not "where are the C++ compilers?", but will we ever see a C++ compiler? GCC for example has their own propaganda written up over how much they support the in progress second C++ standard, without even worrying about the first standard, or even showing a page of how far that is completed yet. Even Microsoft has a page describing some of their caveats. The only little snippet GCC has is this.
Even more disconcerting is that RMS, the idiotic hypocritical redefinitional head of the FSF says he prefers not to have support for "export" in GCC, and prefers it if GCC doesn't follow the standard. His chutzpa is so bad, that he even asked the standards committee if they can change the standard to reflect what he's implemented in GCC, and remove the export keyword altogether, since he doesn't want it to be there.
Of course someone may wonder what is the big fuss about the export keyword anyway. Good C/C++ programmers know that when breaking up functions into different files, it's best to put sizable functions in the C/C++ file, and prototypes for them in the header files for other functions elsewhere to use. The export keyword is supposed to tell the C++ compiler that the current function uses templates, and it needs to have a special uncompiled (but perhaps middle representation) version of the function saved separately to be able to link with other code that calls that function properly.
The problem with export here is that some of the code won't be compiled until link time, meaning a more annoying link process, and the possibility of compile errors at link time. So we have to decide which is the lesser of two evils, either start sticking code in headers files (as people are now forced to do), or have code compile at link time (which people like RMS don't even want to give us the freedom to do). Or do we? Is there perhaps another implementation option?
For MSVC, where Visual Studio itself, annoyingly, won't let you compile a file without having a whole project for it can in fact use this to its advantage. Since it has a full file list, and also keeps class lists and other things such as function prototypes handy for auto completion and tool tip hints, it already knows where it has to grab actual code from. An IDE like Visual Studio just has to pass its compiler the actual file to compile, and a list of other files to pull templates from, and it's all transparent to the programmer. Any compiler could do this, although it would probably get quite annoying if you have to specify all the locations by hand. Of course a sane default might be to try to find '.cpp' files to match any template function prototype in a header file included by the current C++ file that is being compiled.
Post your thoughts on this subject, and any other ideas you might have to sanely implement the export keyword in C++ without running into some of the cons listed above.
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