I downloaded Clang 3.6.2 from this website and am trying to set it up with Code::Blocks under Windows. Unfortunately, it fails to compile a simple "hello world" program on the grounds that it doesn't know where iostream is.
Looking through the install folder, it does not appear to include a standard library with it. Why? And how do I get it?
The standard library is NOT part of the compiler itself. It is part of the runtime environment on a particular platform. Sure, some organisations put together a "kit" with all the necessary parts to build an application - there may even be someone that packages a Clang compiler with a suitable runtime.
In general, you should be able to download the Windows SDK and get the relevant header files there - and if you use clang-cl, it should be largely compatible with the MSVC compiler [or provide clang or clang++ with the correct -fms-compatibility or whatever it is called].
Or as suggested in the other answer, use libcxx, but it's not 100% complete for Windows.
They do have a c++ standard library: libcxx.llvm.org. But it's not fully supported on the windows platform.
Related
I'm new to Windows programming and found that lots of prebuilt libraries for Windows offer libraries like lib-mingw, lib-vc2019, lib-vc2017...
Could anyone help to point out
what is the difference? Which library should I use in what case?
If I want to use Clang on Windows, which one should I use?
Why these different libraries rarely seen on Linux (let's say
Ubuntu), does package managers like apt hide this detail? In other word, why there's no such thing like lib-gcc.a, lib-clang.a on Linux platform?
Mingw (GCC), VC2019 and VC2017 are different compilers. Use the library corresponding to your compiler.
I'm not sure but I think none of them will work with Clang. At least on Linux GCC and Clang are very similar. I mean they are mostly binary compatible, many same compiler flags, many same compiler extensions. Clang tried to make it possible to easily replace GCC in your build pipeline. But all these information is for Linux.
These libraries are not seen on Linux because all these compilers are Windows compilers
You can always build a library with your compiler to use it in your project with your compiler (if you have the sources).
If it's a third party closed source library and you are a paying customer you can ask if they build it for you. It's usually better the add a new compiler to the build pipeline than to lose a customer.
I was doing a c++ homework which would be compiled with g++4.4.7, but I have some downgrade problem, so I decided to compile it with higher g++ version, but I don't know what library can be used in g++4.4.7, are there any document I can check?
By the way, can vector be included in g++ 4.4.7 ?
Downgrading your compiler can be a mess. I wouldn't recommend it. I also wouldn't recommend teaching with such an outdated compiler.
Personally, I would go for one out of 2 approaches: install an old Linux version that comes with this Gcc version in a virtual machine or if it's a handful of files, use compiler explorer.
For virtualization, I only have experience with virtualbox, however other good alternatives exist. You search for a Linux distro that has that version of Gcc and install a temporary computer that way. Once the course is finished, you throw the machine out and your current system ain't affected.
The easier alternative is to simply plug your files in compiler explorer, it has a lot of different compiler versions including the compiler you need.
It does require you to enter file by file, so I would recommend writing a script to (recursively) resolve your local includes and create a simple preprocessed file that you can plug in the site.
For sure, write your code with a supported version of c++, don't use c++2a features when coding.
I recently downloaded mingw from http://www.mingw.org/ and installed its c++ compiler and dependencies, which include installing standard library headers. I have also successfully compiled a hello world program, compilation is fine, and common old headers are there and work fine (such as string.h).
However, when I attempted to #include <any>, it threw an error that any.h does not exist. And sure enough, when I look in mingw\include\, there is no any.h (and I see other things missing, such as variant.h).
I've looked through the mingw package manager, and I have the standard library stuff installed, and there's nothing else relevant to install. Does minGW support C++17? If so, how can I get these newer header files? It seems like this should be something really obvious.
You need mingw-w64, which provides more recent GCC versions:
http://mingw-w64.org
You can find a 7.2.0 download here:
http://mingw-w64.org/doku.php/download/mingw-builds
The any feature requires C++17 support, so if your compiler implementation actually does support it, you probably want to specify it on the command line like this:
g++ -std=c++17 a.cpp
Of course, this requires a modern C++ compiler, like that you can get from nuwen.net.
I have searched Google but haven't found quite a direct answer to my queries.
I have been reading C++ Primer and I'm still quite new to the language, but despite how good the book is it discusses the use of the standard library but doesn't really describe where it is or where it comes from (it hasn't yet anyway). So, where is the standard library? Where are the header files that let me access it? When I downloaded CodeBlocks, did the STL come with it? Or does it automatically come with my OS?
Somewhat related, but what exactly is MinGW that came with Cobeblocks? Here it says
MinGW is a C/C++ compiler suite which allows you to create Windows executables without dependency on such DLLs
So at the most basic level is it just a collection of "things" needed to let me make C++ programs?
Apologies for the quite basic question.
"When I downloaded CodeBlocks, did the STL come with it?"
Despite it's not called the STL, but the C++ standard library, it comes with your c++ compiler implementation (and optionally packaged with the CodeBlocks IDE).
You have to differentiate IDE and compiler toolchain. CodeBlocks (the Integrated Development Environment) can be configured to use a number of different compiler toolchains (e.g. Clang or MSVC).
"Or does it automatically come with my OS?"
No, usually not. Especially not for Windows OS
"So, where is the standard library? Where are the header files that let me access it?"
They come with the compiler toolchain you're currently using for your CodeBlocks project.
Supposed this is the MinGW GCC toolchain and it's installed in the default directory, you'll find the libraries under a directory like (that's what I have)
C:\MinGW\lib\gcc\mingw32\4.8.1
and the header files at
C:\MinGW\lib\gcc\mingw32\4.8.1\include\c++
"So at the most basic level is it just a collection of "things" needed to let me make C++ programs?"
It's the Minimalist GNU toolchain for Windows. It usually comes along with the GCC (GNU C/C++ compiler toolchain), plus the MSYS minimalist GNU tools environment (including GNU make, shell, etc.).
When you have installed a C++ implementation you'll have something which implements everything necessary to use C++ source files and turn them into something running. How that is done exactly depends on the specific C++ implementation. Most often, there is a compiler which processes individual source file and translates them into object files which are then combined by a linker to produce an actual running program. That is by no means required and, e.g., cling directly interprets C++ code without compiling.
All this is just to clarify that there is no one way how C++ is implemented although the majority of contemporary C++ implementations follow the approach of compiler/linker and provide libraries as a collection of files with declarations and library files providing implementations of these declarations.
Where the C++ standard library is located and where its declarations are to be found entirely depends on the C++ implementations. Oddly, all C++ implementations I have encountered so far except cling do use a compiler and all these compilers support a -E option (although it is spelled /E for MSVC++) which preprocesses a C++ file. The typically quite large output shows locations of included files pointing at the location of the declarations. That is, something like this executed on a command line yields a file with the information about the locations:
compiler -E input.cpp > input.ii
How the compiler compiler is actually named entirely depends on the C++ implementation and is something like g++, clang++, etc. The file input.cpp is supposed to contain a suitable include directive for one of the standard C++ library headers, e.g.
#include <iostream>
Searching in the output input.ii should reveal the location of this header. Of course, it is possible that the declarations are made available by the compiler without actually including a file but just making declarations visible. There used to be a compiler like this (TenDRA) but I'm not aware of any contemporary compiler doing this (with modules being considered for standardization these may come back in the future, though).
Where the actual library file with the objects implementing the various declarations is located is an entirely different question and locating these tends to be a bit more involved.
The C++ implementation is probably installed somehow when installing CodeBlocks. I think it is just one package. On systems with a package management system like dpkg on some Linuxes it would be quite reasonable to just have the IDE have a dependency on the compiler (e.g., gcc for CodeBlocks) and have the compiler have a dependency on the standard C++ library (libstdc++ for gcc) and have the package management system sort out how things are installed.
There are several implementations of the C++ standard library. Some of the more popular ones are libstdc++, which comes packaged with GCC, libc++, which can be used with Clang, or Visual Studio's implementation by Microsoft. They use a licensed version of Dinkumware's implementation. MinGW contains a port of GCC. CodeBlocks, an IDE, allows you to choose a setup which comes packaged with a version of MinGW, or one without. Either way, you can still set up the IDE to use a different compiler if you choose. Part of the standard library implementation will also be header files, not just binaries, because a lot of it is template code (which can only be implemented in header files.)
I recommend you read the documentation for the respective technologies because they contain a lot of information, more than a tutorial or book would:
libstdc++ faq
MinGW faq
MSDN
I want to know a programming language that doesn't require a runtime/dependency to be installed on the target system. My primary target is Windows XP and above.
I tried Autohotkey but it dosent have many advance functions.
Firstly, please confirm that does 'C++' requires to install a runtime/dependency on the target system is is Win XP or later. Secondly, please suggest me an alternative to C++ that doesnt require a dependency to be installed.
UPDATE: I will be using CodeBlocks! Does the C++ code compiled with that requires a dependency?
UPDATE: Sorry for the misconception, by CodeBlocks I mean the default compiler of CodeBlocks (ie: GNU GCC Compiler or MinGW).
Everything usually depends on the project, not the language. For example, programs compiled in Visual Studio's C++ uses some runtime libraries to work properly. However, you can configure the project in such way, that these libraries are included in the executable file, thus not needing additional dependencies. Delphi works similarly.
Here's the setting for Visual Studio Project:
If you choose option with "DLL", your program will require runtime DLLs. Otherwise it will be standalone, the runtimes will be incorporated into your binary file.
Edit: In response to question edit
I'll repeat myself: it depends on project, not the compiler or IDE.
If you want to create a program that does not require anything else in order to run, except for base operating system (no .NET, no Java, no Perl, no runtime libraries, etc), then your best bet is to use C or C++ and compile your program as single statically compiled executable.
It is rather difficult to achieve in practice, but it can be done.
Codeblocks is not a compiler, but an IDE, that can use different compilers.
The most common one is MinGW.
To complie with minGW so that all the standard libraries are statically linked you shold configure your project (see "project settings") so the the linker options include the -static flag.
You can even be more specific by stecifying
-static-libgcc
-static-libstdc++