I'm using GNU Arm Embedded Toolchain 10-2020-q4-major (arm-none-eabi-* 10.2.1) and I would like to take advantage of modern c++ features.
So I'm trying to find out which c++ features (language core features as well as libstdc++ features) are available with this particular toolchain. I read through this matrix https://gcc.gnu.org/projects/cxx-status.html, and they don't seem to distinguish between different compiler ports.
How could I find if I could use C++17 or C++20 features for example ?
Regards,
Hugo
As you can see on the gcc.gnu site you listed, all of the C++17 and C++20 features are listed. The "Available in GCC?" specifies which version of the GCC compiler is required to have a given feature available. It is essentially not your toolchain, but the compiler (as part of that tool chain) that defines your feature set.
In your given case, that you are using a GCC compiler for arm-non-eabi architecture, does not change this feature set, the version of the compiler does. So, with your arm-non-eabi-g++-10.2.1 you should have all the features for that compiler version available.
Related
I need a portable way to determine alignment requirements of a structure, where portability includes legacy versions of GCC. Parts of project are stuck with embedded platforms supporting pre-C++11 standard only, as early as GCC v.3.6.
There is a non-ISO __alignof__ (a macro? a function?) analog of C++11 operator alignof which I can use, but what is the earliest version of GCC compiler would support it? Were there alternatives or changes in naming?
The oldest version of GCC with documentation available online at gcc.gnu.org is 2.95.3. That version does support __alignof__ extension.
Given
Cross-platform C++ project that has to build on some ancient windows mobile platforms. However the development is done with GCC.
Problem
Every time that C++11 feature is used it will build locally but fail on the build server (mobile windows).
Question
Is it possible to configure GCC to somehow warn if C++11 feature is used in our code-base (excluding other source-dependencies).
What have you tried?
I know about using -std=c++98 -pedantic, but:
I would like to use the latest compiler standard on Linux platform
There are some linux-only third-party dependencies (build from the source) that require C++11
Build the code you need to be C++98 compatible using C++98 flags.
Build the code you need to be C++11 compatible using C++11 flags.
Examine the documentation of the compiler and standard library used to ensure ABI compatibility between code built with C++98 and C++11; you may have to (for example) use C++98 strings in your C++11 code in order to have ABI compatibility, assuming you pass std::strings between the C++98 and C++11 code bases.
You cannot both use C++11 and not use C++11 when building the same file, unless you build it twice. Which is also an option; build the C++98 compatible stuff twice, once with C++latest and once with C++98. Throw away the C++98 build after halting on errors and warnings.
I am trying to install MongoDB driver and is reading this following section
https://github.com/mongodb/mongo-cxx-driver/wiki/Download-and-Compile-the-Legacy-Driver
SCons Options when Compiling the C++ Driver
Select options as appropriate for your environment. Please note that some flags may not be available on older versions.
Important note about C++11/C++14: The boost libraries do not offer a stable ABI across different versions of the C++ standard. As a result, you must ensure that your application, the C++ driver, and boost are all built with the same language standard. In particular, if you are building the C++ driver with C++11 enabled, you must also build your application with C++11 enabled, and link against a C++11 compiled boost. Note that on most systems, the system or package installed boost distribution is not built with C++11, and is therefore incompatible with a C++11 build of the legacy driver.
Important note about the C++ standard library: Much like the C++11 issues, it is again critical that all three components (your application, boost, and the C++ driver) be built against the same C++ runtime library. You cannot mix components that have linked against libc++ with those that have linked against libstdc++.
Important 26compat Note: If you are using the 26compat branch, the install-mongoclient target is only enabled when the --full flag is provided. Similarly, you must use the --use-system-boost flag when building 26compat.*
My main question, I am trying to find out what standard my visual studio 2015 is running on when I build solution. I have tried to read around but I think I misunderstood the concept of C++11 and C++14. On Microsoft page it mentioned that VS2015 supports C++11,C++14 and C++17. But how do I know what am I using now? I can't find a way to explicitly configure. I am new to C++ and have been coding Java for many years. C++ is confusing to me because there are so many variety such as compilers and standards. Please help me understand and possibly find out what standard I am running.
The text is mostly nonsense.
ABI's are dictated by compilers, not standards. There is no ABI for C++11, there's one for GCC and a different one for MSVC2015.
"C++11 enabled" is a setting on GCC, and it does affect their ABI. The same applies to libc++ versus libstdc++, neither is part of the C++11 standard. Also, the mixing of build environments and the OS ("system Boost version") is mostly a Linux thing.
MSVC++ isn't GCC, and it doesn't use libstdc++, so all this does not affect you. And Boost versions aren't even a MSVC++ setting anymore, for the last few versions library configuration has been a per-project setting instead. (Tip: Create a Boost.vsprops file for that)
I am having trouble understanding the different compilers that are available to me.
I mainly use Xcode for writing and compiling, and in Xcode's preferences, there are all of these options for C++ compilation:
C++ Language Dialect:
C++98[-std=c++98] through C++14[-std=c++14]
GNU++98[-std=gnu++98] through GNU++14[-std=gnu++14]
C++ Standard Library:
libstdc++ (GNU C++ standard library)
libc++ (LLVM C++ standard library with C++11 support)
Can someone explain what exactly all of that ^ is?
I understand that (and correct me if I'm wrong), that apple no longer distributes GCC with Xcode and use Clang instead?
If that were the case, then why does Xcode have the option for GNU C++ standard library? Doesn't GNU make GCC?
What compiler is invoked when I run C++ code in my local terminal with g++ filename.cpp?
Is there any way to make sure that this g++ "compiler" is up to date?
What's the difference between compiling with g++ in the terminal and using Xcode?
Also, what would be the difference if I tried running C++ programs with Clang?
My class requires us to test our programs on the department's server's compiler via ssh from my terminal. The server is a Unix machine and I know that its compiler is GNU's GCC compiler and we also access it using g++. Does this mean that the local g++ in my terminal is also GCC?
edit: Grammar
1.
C++ language dialect
C++98[-std=c++98] through C++14[-std=c++14]
GNU++98[-std=gnu++98] through GNU++14[-std=gnu++14]
The C++ language has evolved over time. These are the various versions of the language that are available to you. If you have to be compatible with something old, you might be forced to use an old one. Otherwise you'd probably want ot use the newest available, which is c++14 in the list above. 14 stands for 2014, 98 for 1998 - it is supposed to represent the year that version of the standard was blessed.
In addition to standard C++ there are non-standard extensions. Gnu is a compiler "manufacturer", the "GNU" above is the non-stanadard extensions as specified by GNU for a particular documented version.
C++ Standard Library:
libstdc++ (GNU C++ standard library)
libc++ (LLVM C++ standard library with C++11 support)
In addition to the base language, the standard library is also a part of the standard. These are two different implementations of the standard library. The first is by GNU, the second by llvm. llvm are a different compiler manufacturer.
On osx you'd probably use libc++ as I believe the llvm compiler (clang++) is now standard there. The llvm compiler will support the gnu extensions if you need them. You probably don't. Just use the latest version of whatever is default.
Yes
two different pieces, the compiler and the standard library. You can use clang++ with libstd++
g++ -v will tell you
not really. Update xcode to the newest or start looking at homebrew or ports to get the latest and greatest they package of whatever compiler you like.
Probably the same compiler, you can set it either to point at any compiler you have installed. So what each points at is your choice.
both g++ and clang++ are standards compliant. You're unlikely to notice much difference. They will complile the same source files into equivalent binaries.
run g++ -v in any terminal to see exactly what it is.
I am considering the use of some C++11 features (like auto for instance) in some cross-platform projects (Windows+Mac). On Windows, Visual Studio supports parts of the upcoming C++11 standard that would allow me to simplify parts of the code base so naturally I would be interested in starting to use these features.
But as far as I am aware, the current XCode version (3.2.4 + GCC 4.2) does not support any C++11 features at all. Can I upgrade the GCC version or the CLang version somehow? Or should I just bite my tongue and wait for Apple to package a new version sometime in the future?
Xcode 4.2 had finally added support for C++0X:
In the project build settings screen, switch on "All" options.
In the "Build Options" section, set compiler to "Apple LLVM compiler 3.0".
Scroll down to "Apple LLVM Compiler 3.0 - Language" section and set "C++ Language Dialect" to "C++0X" and "C++ Standard Library" to "libc++".
The std::move(), move constructor and R-Value reference are known to work as expected, and I'm testing on the std::thread and std::atomic.
======= Update 2012: =======
Start with Clang - Many C++11 features are now available in Clang. It's included with Xcode.
======= Original answer from Jan 2011: =======
intel's compiler may be the cleanest way to go at this time.
http://software.intel.com/en-us/articles/intel-composer-xe/
clang's promising, but not particularly stable or featured wrt c++0x features. c++ is still very new for clang.
gcc: relatively mature, but you'll have to write and maintain your compiler plugins for xcode.
you can also specify custom scripts, but that is a pain to maintain... unless you go all out and create an adaptor tool.
Xcode uses the GCC or the Clang C++ compilers. Any features supported by those compilers are fair game. GCC's C++ compatibility page is here and the Clang C++ compatibility page is here.
I've found auto, decltype(), range based "for (:)" work in a cross platform project (LLVM for MacOSX,iOS, gcc/linux, MSVC 10/windows).
lambdas & variadic macros don't appear to work under LLVM yet sadly.