I've found a company that provides GCC based toolchains for ARM, MIPS but I don't know in what are they different from the vanilla GCC, of course, they bring other software pieces such as Eclipse, but when looking only at GCC and Binutils, are they different or just the same?
One big difference between a pre-compiled toolchain (like those provided by Code Sourcery, MontaVista, Wind River, etc) and one built from source is convenience. Building a toolchain from scratch, especially for cross-compiling purposes, is tedious and can be a complete pain. Also, the newest versions of glibc (or uClibc), gcc, and binutils aren’t always compatible as they're developed independently. There are open source tools to make this process easier (like crosstool-NG), but having a proven toolchain that’s been optimized for a certain platform can save a lot of time and headaches. This is especially true at the beginning of a new project. It also helps to have technical support when things go screwy. Of course…you have to pay for it most of the time.
That being said, compiling your own toolchain will most likely save you money and can allow more flexibility down the road. MontaVista, as far as I know, doesn’t include support for older platforms in their newest toolchain releases. For example, if you bought MontaVista Pro 4.X and it included a toolchain with gcc 3.3.X, that’s the toolchain you’re most likely going to be stuck with for the life of your project. Upgrading to a toolchain with gcc 4.X most likely wouldn’t be an option.
Hope that helps.
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As far as I understand(Correct me if i'm wrong), the output of a compiler depends on the Architecture version used, Compiler, and operating system.
Lets say Im using ubuntu release 16.04 x84-64 and compiling a c file with gcc version 5.4(or any other mix of OS,arch,compiler for the example) .
As I understood it until now, if I were to compile the same c file but with a different ubuntu release, with the same arch and compiler version it should have produced the same assembly code.
After a few tries I have got the impression that this is incorrect, how is this possible?
Does the output of a compiler depend on the release of the specific OS?
One of the examples is compiling https://github.com/tbuktu/libntru on 2 different ubuntu versions and receiving different assembly.
The different OS's may have different versions of the default libraries installed (which get linked into your final application). Thus the end result may be slightly different.
If you are just doing a few ubuntu versions the odds of differences goes down as the overall architecture differences may not be reflected either in your test or may not change on the same os family with the same compiler family for long periods of time. Where you are more likely to see differences in a test like that is as you get older versions of the same distro, newer/newest versions of the compiler are not ported/supported directly as an apt-get. maybe you can get them to work by hand building but gcc in particular is really bad about that their code only builds with relatively recent prior or following versions get too far apart and gcc cant build gcc. What I would first expect to see is strictly due to gcc version differences you start to see differences in the compiler.
A better test is take a simple .c file and build for windows any version (using the same version of gcc built for that system) and ubuntu/linux any version. Should more quickly see differences.
Two different compilers should show differences for reasonably sized projects, or knowledge based targeted small code samples, llvm/clang vs gcc for example. Different versions of the same compiler or compiler family will somewhat by definition show differences over time, does 6.x vs 6.x+1 gcc show differences well yes if you know where to look but often not, but gcc 3.x vs gcc 7.x should and then depending on the test you can narrow in from there.
You have compiler to compiler differences on the same os and system that are expected to show differences.
You have various reasons why system to system differences with the same compiler will show differences.
And then combinations of the above would naturally also show differences.
The bigger question is why do you care, the educational information is that you shouldn't expect the same C source code to build the same way if you change the compiler, compiler settings, or operating system. It can have anywhere from no differences to huge differences based on any of the above. Starting quite simply with optimization and other tuning settings and going from there.
I was wondering which compiler is better to use on Windows OS (8.1) in temrs of compatibility to c++11's (and later 14) functions, liberies and features (like lambdas) and is also comfortable to use (less bugs).
I am a university student hence I'm not looking at the subject product-wise (even though I do like to code a bit more than just projects for my studies).
I am currently using eclipse luna IDE if it matters.
Notice that compiler != IDE.
VC++ is one of the most populars on Windows and depending on its version it has a good support for C++11 features. Check the list on the msdn blog to find out if there's everything you need.
Gcc is also ported to Windows and you can install MinGW to use it (4.8.1.4 at the moment of writing this). It is pretty complete on C++11.
Clang is also available for the Windows platform and it is also complete on C++11 support (plus it has good diagnostic messages), but notice that you will have to use another linker since clang doesn't ship with one (although there is an ongoing effort to write it: http://lld.llvm.org/)
All the compilers I cited above are pretty stable but, based on my experience, if you're looking for latest and greatest C++11/14/17 features, you might just want to go for gcc or clang (VC++ is slower in adding support for newest features and the compiler is undergoing a huge update to modernize). Just keep in mind that these are compilers and not just IDEs, an IDE is a front-end supporting program that uses a compiler undercover to compile files.
To set up a C++11 compiler, I suggest installing MSYS2, it has a package manager (pacman) that can install fresh versions of GCC, GDB, Clang and many libraries like SDL, Lua etc. Very easy to use too.
As far as GCC vs CLang goes - I really tried hard to make CLang work (which is presumably faster and more friendly than GCC - produces better warnings, etc.), but failed. Issues were that CLang (which comes with MSYS2) is hard-coded to use GCC linker which produces some strange linker errors when using libstdc++ (std implementation from GCC). libc++ (a new implementation designed to work with CLang) didn't worked for me on Windows either.
So you either try build CLang from sources and hope that some configuration will work with C++11 library, OR just stick with GCC which works just fine out of the box.
As IDE, I suggest to take a look at CLion. It is very comfortable (infinitely more user-friendly and intuitive than Visual Studio, IMO). Just install it and point it to the mingw64 (or mingw32) folder of MSYS2, it will auto-detect everything for you.
It only works with CMake projects though.
I'm developing a GPS application under Linux, with ARM7 microprocessor.
Which compiler do you recommend? Do you know if there is any toolkit with libraries ready to develop GPS applications?
A friend of mine recommended gcc... what do you guys think about it?
Thank you
I don't think that the compiler matters that much. What is more important is your precise understanding of the library you are using, or of the actual device you are invoking.
However, I will recommend GCC, and I do recommend using a very recent version of GCC. For instance, GCC 4.6.2 is appearing these days, and there have been lot of work recently put in GCC to improve its perfomance for ARM processors. So, if possible, us a 4.6 GCC, not a 4.3 one (some hardware vendors don't give recent GCC with their ARM development kit; you should consider in that case building your GCC (and perhaps binutils) from their source code.
I know nothing about GPS itself.
Setup: I installed Cygwin with the GNU programming lineup (gcc, g++, make, and gdb) and successfully compiled an ran a program that I was working on. Then I decided to install boost into Cygwin because I will need to use typical boost stuff as my program develops. So, using the Cywing setup.exe, I installed boost. After this, the program that I had just successfully compiled and ran no longer worked. (And recall that it didn't depend upon boost.)
I found out that when boost installed, it also installed a new compiler, g++-4.exe, whereas previously I had been using r++-3.exe. Boost had also symbolically linked g++.exe to the new compiler. After I changed back the symbolic link my old program compiled correctly.
Is there any reason that I should be using g++-4 rather than g++-3?
g++ 3 is very old and the gcc community has long since dropped maintenance of it. (GCC 4.3 is currently the oldest maintained release series.) There have been lots of language conformance improvements in newer versions (both in accepting valid code and rejecting bad code), so you'll have an easier time going forward if you bite the bullet now. You can check the release notes for each series (e.g. for 4.0) for explanations of these improvements and the code changes they might require. Personally, I find programming much more enjoyable when I can reason about programs according to a precise language specification, and only rarely be forced to understand the quirks of a particular compiler.
Also, Boost support for g++ 3 seems to be nearing an end, as Boost 1.44 considers GCC 3(.4.6) as an "additional test compiler" on only a single platform (RHEL). Boost development is linear (not branched), so you can find yourself in a situation where you need to upgrade to get bug fixes, but then find that your platform is no longer supported.
MSYS and UNIX-like build systems apart; why does Mingw exist? What I mean is, why isn't win32/64 just another target available in "vanilla GCC"? Are there technical reasons for this or are they "political"? It would seem to me that there isn't really anything special about the Windows platform that would make a GCC port to it "incompatible" with the original GCC.
Mingw isn't just the compilers - it's also the libraries and headers (and whatever other support files you might need).
GCC is just a compiler. Mingw is a full environment.
MingW is intended to allow easy porting of Posix apps to windows. It's simply a "thinner" layer than CygWin, so not everything might work where windows too different. CygWin allows provides enough insulation that even the scripting tools to build and generate code run.
Edit:
Microsoft is very fond of making there own standards, and want to put there own brand on things for which open standards already exist. i.e. OpenGL -> DirectX, Java -> .net, OpenCL is the next standard they want to spurn. This makes them a bit of a pain for non sponsored project to support them as a target. They have always turned away from anything that allows easy cross platform development, because they only want you to develop your app for there OS. It's a marketing strategy, control the brand, control the platform, and make it painful for people to support other OSes. MingW is required because GCC can generate x86 code, but even the most basic runtime support is different than Posix based OSes.
well, while you can use cross compiler to produce win32/64 binary codes from GCC, someone has to port all the C runtime libraries across though. Both Mingw and Cygwin are created for this purpose.
From MinGW's main site
Offered in easily installed binary package format, for native deployment on MS-Windows, or user-built from source, for cross-hosted use on Unix or GNU/Linux, the suite exploits Microsoft's standard system DLLs to provide the C-Runtime and Windows API.