How to get "g++ -mx32" to work on RHEL 7.2 - c++

I am new to x64_86, but forced to use it because RedHat dropped its 32-bit OS support in RHEL 7.x. I have to complile a lot of code, and am not ready to jump to x64 yet (because I do not need 64-bit addresses and do not want to face all related porting issues). So I have considered using -m32 and -mx32, and decided that -mx32 is the best route for me. However, while -m32 works fine on my build machine, when I use -mx32, I get this error:
In file included from /usr/include/features.h:399:0,
from /usr/include/string.h:25,
from zz.cpp:1:
/usr/include/gnu/stubs.h:13:28: fatal error: gnu/stubs-x32.h: No such file or directory
# include <gnu/stubs-x32.h>
^
compilation terminated.
I searched the web for solutions and some links indicate that I have to install some mysterious "multilib" rpms for g++ and gcc, however, I cannot find these anywhere. Others suggest that I have to install Linux in the x32 mode and build libgcc for x32, which sound extreme. Any ideas or leads? Did someone actually try g++ -mx32? Maybe it is not even supported on the RH platform... Thanks!
P.S. In order to get the "-m32" option to work I had to install:
yum install glibc-devel.i686 libgcc.i686 libstdc++-devel.i686 ncurses-devel.i686
This one fails (yum cannot find these RPMs) - allegedly these are required for -mx32 to work:
yum install gcc-multilib g++-multilib
:(

Multilib is indeed your answer, but do not know why your repo does not support it. I installed mine via apt-get:
sudo apt-get install gcc-multilib
Although it uses 64-bit instructions, it uses the 32-bit ABI so annoyingly will not run under WSL (Windows Linux subsystem), which only supports the 64-bit one.

Related

How to recover system gcc compiler on centos 6

I am running centos 6 on a cluster. I installed the latest gcc-8.2.0. and made a link "ln -sf /usr/bin/gcc-8.2 gcc".
I did the same for g++ and gfortran.
I wanted to reinstall gcc-8.2.0 and went ahead to
make clean
in the gcc-8.2 directory.
When I try
./configure
I get that C compiler cannot create executables
The links I made are broken.
The system gcc-4.4.7 cannot be found
which gcc
gives no gcc
sudo yum install gcc gcc-c++
gives gcc is already installed.
I tried to install an rpm, which fails because of dependencies.
I have pg compilers installed in /opt/pgi
When I configure with
CC=/path to/pgi/bin/pgcc FC=/path to/pgi/bin/pgfortran ./configure
I still get C compiler cannot create executables
I tried the following c++ programm
#include <iostream>
using namespace std;
int main() {
cout << "Hello world!" << endl;
return 0;
}
With the command
/opt/pgi/linux_86_64/12.08/bin/pgcpp hello.cpp -o hello
It gives compilation error that float.h not found. On another linux PC with working gcc, the program works with the command
g++ hello.cpp -o hello
I will appreciate any assistance to either find the systemgcc or use pg compilers to compile gcc if possible
I admit it is a big mess which will require OS reinstallation and reconfiguration. But then I did
sudo yum install compat-gcc-34
Now I have gcc34 and configure of gcc-8.2 goes through without "c compiler cannot create executables". (Note that the ./configure referred to in earlier post was actually
../gcc_8_2_release/configure
inside "gcc_8_2_release_build, so gcc was not being built in its source directory.
The problem I have now is with make, which needs g++, giving error
uint_t(64) or int_t(64) not found.
Thanks all who have gone through this post, for your patience.
Any assistance will be appreciated.
Here is how I got out of this mess.
With the following two commands
sudo yum install compat-gcc-34-c++
sudo yum install compat-gcc-34-g77
I was able to install the older version of gcc, c++ and g77. Then I was able to build gcc-8.2.
Now I have a functional system with the latest gcc, yes it may need re-installation/re-configuring but it is fully functional.
I have learnt a lot and very much appreciate the comments and guidelines of #Basile. However, at one point he was rather negative and discouraging.
But thanks to my belief and perseverance, and more importantly browsing the knowledge shared by others, I have been able to recover what I was beginning to be convinced was a lost cause.
Thanks all.
This is more a sysadmin question than a programming one.
My recommendations:
don't mess your /usr/bin/. Leave your package manager yum to fill it -and never add anything inside it without yum ; so remove manually any symlinks you made there (by mistake)
reinstall the old system gcc 4.4 and g++ 4.4 (using yum)
rebuild your GCC 8 from scratch from its source code. Configure it with --program-suffix=-8 (but no --prefix, or a --prefix=$HOME/soft/ if you don't have root access). So it will install /usr/local/bin/gcc-8 and /usr/local/bin/g++-8 etc... (or, if you have given --prefix=$HOME/soft/ , a $HOME/soft/bin/gcc-8 etc...)
create a $HOME/bin/ if you don't have already one
be sure to have $HOME/bin/ early in your $PATH (before /usr/bin/)
add a symlink ln -sv /usr/local/bin/gcc-8 $HOME/bin/gcc and likewise for g++ etc..
Then, when you type gcc you are getting that symlink to /usr/local/bin/gcc-8 etc.
If you cannot write to /usr/local/ (e.g. because you don't have root permission...) you could pass --prefix=$HOME/soft/ to GCC 8 .../configure then replace /usr/local/ above with $HOME/soft/
If you are the sysadmin and can write to /usr/local/ and have to set up things for many users: add a symlink ln -s /usr/local/bin/gcc-8 /usr/local/bin/gcc etc and ask your users to put /usr/local/bin/ in their $PATH before /usr/bin/
BTW, notice that it is explicitly documented that GCC 8 (or others) need to be built outside of its source tree: in Installing GCC you can read:
First, we highly recommend that GCC be built into a separate directory from the sources which does not reside within the source tree.
(the "highly recommend" should be considered as a polite way to say "you absolutely should")
So your ./configure was another mistake.
It could happen that you messed up your system more seriously than you thought (and perhaps you need to reinstall, or to call Redhat support).
PS. I don't know Redhat (used it only in the previous century). My favorite distro is Debian/testing or Debian/unstable (and my computers are desktops, not clusters).
This problem was solved by the following commands
sudo yum install compat-gcc-34-c++
sudo yum install compat-gcc-34-g77
Once this older version of gcc is installed, the latest version, gcc-8.2 was built and the system is no longer messed terribly. It is very healthy and fit.

How to use previous versions of g++

I am currently running a debian Jessy whose g++'s version is 4.9. For some reason I need to compile a code in g++-4.7 or previous version.
I got the files of gcc-4.7 and g++-4.7 from a debian wheezy of a friend who has g++-4.7.
I tried to make the apt-get install, it seemed to have worked for the gcc but not for the g++. I put the files in the /bin, but he doesn't seem to locate the g++-4.7 package.
When I try to compile my code I specify g++-4.7 but get the error :
g++: error trying to exec 'cc1plus': execvp: No such file or directory
Any idea how to figure this out?
My advise is to add the wheezy repositories to /etc/apt/sources.list and then install g++-4.7 using apt-get. Using this method you will also get bugfixes etc.
I guess, currently you're just having dependency Problems. These will be solved when you use apt-get.
It is very easy to install gcc from sources. Remember that you have also to use a binutils version which maps to the gcc version. Mostly it is possible to run older gcc versions on actual binutils, but I have also seen a problem during install.
I have installed a long list of gcc versions in /opt/
Simply copy an older gcc version somewhere in the file system can result in problems with using the correct library versions.
If you install different gcc versions and also the related libraries e.g.libstdc++ , don't forget to update your library data base ( ldconfig/LD_LIBRARY_PATH/...) Maybe http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html can help.

mingw without g++ compiler

i am new to linux and I have the following question:
I am trying to install MINGW in Ubuntu.
I ran the command:
sudo apt-get install mingw-w64
It was installed, and if i put the command gcc it runs ok. The problem is g++ command does not work. I guess it is because i don't have the c++ compiler (as I read in similar questions in stackoverflow).
I read too that you can use the next command:
mingw-get install g++
but i don't have the executable program for this command.
My question is, how can I install that executable? or is there another way to update my mingw so I can use the g++ compiler?
Hope I have explained myself correctly. Thank you for any help I receive.
mingw-get is a windows specific package manager, it is not needed when you use a native linux package manager such as APT.
Installing package mingw-w64 depends on package g++-mingw-w64, which depends on g++-mingw-w64-i686 and g++-mingw-w64-x86-64.
These packages install the mingw cross compilers as
/usr/bin/x86_64-w64-mingw32-g++-posix
/usr/bin/x86_64-w64-mingw32-g++-win32
/usr/bin/i686-w64-mingw32-g++-posix
/usr/bin/i686-w64-mingw32-g++-win32
Older versions of mingw cross compiler shipped /usr/bin/i586-mingw32msvc-c++, which is replaced by i686-w64-mingw32-c++-win32
You can usually use this toolchain in a project by running ./configure CXX=i686-w64-mingw32-c++-win32 or make CXX=i686-w64-mingw32-c++-win32
Note: the above description is correct for the most recent toolchain in Debian unstable. It may need some minor tweaking for older systems.

How do I install g++ on MacOS X?

I want to compile C++ code on MacOS X, using the g++ compiler. How do I install it?
That's the compiler that comes with Apple's XCode tools package. They've hacked on it a little, but basically it's just g++.
You can download XCode for free (well, mostly, you do have to sign up to become an ADC member, but that's free too) here: http://developer.apple.com/technology/xcode.html
Edit 2013-01-25: This answer was correct in 2010. It needs an update.
While XCode tools still has a command-line C++ compiler, In recent versions of OS X (I think 10.7 and later) have switched to clang/llvm (mostly because Apple wants all the benefits of Open Source without having to contribute back and clang is BSD licensed). Secondly, I think all you have to do to install XCode is to download it from the App store. I'm pretty sure it's free there.
So, in order to get g++ you'll have to use something like homebrew (seemingly the current way to install Open Source software on the Mac (though homebrew has a lot of caveats surrounding installing gcc using it)), fink (basically Debian's apt system for OS X/Darwin), or MacPorts (Basically, OpenBSDs ports system for OS X/Darwin) to get it.
Fink definitely has the right packages. On 2016-12-26, it had gcc 5 and gcc 6 packages.
I'm less familiar with how MacPorts works, though some initial cursory investigation indicates they have the relevant packages as well.
Installing XCode requires:
Enrolling on the Apple website (not fun)
Downloading a 4.7G installer
To install g++ *WITHOUT* having to download the MASSIVE 4.7G xCode install, try this package:
https://github.com/kennethreitz/osx-gcc-installer
The DMG files linked on that page are ~270M and much quicker to install. This was perfect for me, getting homebrew up and running with a minimum of hassle.
The github project itself is basically a script that repackages just the critical chunks of xCode for distribution. In order to run that script and build the DMG files, you'd need to already have an XCode install, which would kind of defeat the point, so the pre-built DMG files are hosted on the project page.
Type g++(or make) on terminal.
This will prompt for you to install the developer tools, if they are missing.
Also the size will be very less when compared to xcode
Download Xcode, which is free with an ADC online membership (also free):
http://developer.apple.com/technology/xcode.html
xcode is now available for free from the app store. Just "buy it" (for free) and it will download. To get the command line tools go into preferences/downloads and "install command line compiler tools".
Instead of gcc you are using clang, but it works the same.
Here is how to do it on the newer mac chips and how to switch from clang(default) to g++
Install g++ through home-brew.
Check out the version you just installed, probably 12th or higher
You can make a symbolic link from g++-12 to g++
In order to do it, just type in your terminal:
sudo ln -s $(which g++-12) /usr/local/bin/g++.
Now open a new terminal and check your version again and you should see g++ instead of clang
g++ --version

How to compile for Windows on Linux with gcc/g++?

I have written some effects in C++ (g++) using freeglut on Linux, and I compile them with
g++ -Wall -lglut part8.cpp -o part8
So I was wondering if it is possible to have g++ make static compiled Windows executables that contains everything needed?
I don't have Windows, so it would be really cool, if I could do that on Linux :)
mingw32 exists as a package for Linux. You can cross-compile and -link Windows applications with it. There's a tutorial here at the Code::Blocks forum. Mind that the command changes to x86_64-w64-mingw32-gcc-win32, for example.
Ubuntu, for example, has MinGW in its repositories:
$ apt-cache search mingw
[...]
g++-mingw-w64 - GNU C++ compiler for MinGW-w64
gcc-mingw-w64 - GNU C compiler for MinGW-w64
mingw-w64 - Development environment targeting 32- and 64-bit Windows
[...]
Suggested method gave me error on Ubuntu 16.04: E: Unable to locate package mingw32
===========================================================================
To install this package on Ubuntu please use following:
sudo apt-get install mingw-w64
After install you can use it:
x86_64-w64-mingw32-g++
Please note!
For 64-bit use: x86_64-w64-mingw32-g++
For 32-bit use: i686-w64-mingw32-g++
One option of compiling for Windows in Linux is via mingw. I found a very helpful tutorial here.
To install mingw32 on Debian based systems, run the following command:
sudo apt-get install mingw32
To compile your code, you can use something like:
i586-mingw32msvc-g++ -o myApp.exe myApp.cpp
You'll sometimes want to test the new Windows application directly in Linux. You can use wine for that, although you should always keep in mind that wine could have bugs. This means that you might not be sure that a bug is in wine, your program, or both, so only use wine for general testing.
To install wine, run:
sudo apt-get install wine
Install a cross compiler, like mingw64 from your package manager.
Then compile in the following way: instead of simply calling gcc call i686-w64-mingw32-gcc for 32-bit Windows or x86_64-w64-mingw32-gcc" for 64-bit Windows. I would also use the --static option, as the target system may not have all the libraries.
If you want to compile other language, like Fortran, replace -gcc with -gfortran in the previous commands.
I've used mingw on Linux to make Windows executables in C, I suspect C++ would work as well.
I have a project, ELLCC, that packages clang and other things as a cross compiler tool chain. I use it to compile clang (C++), binutils, and GDB for Windows. Follow the download link at ellcc.org for pre-compiled binaries for several Linux hosts.
From: https://fedoraproject.org/wiki/MinGW/Tutorial
As of Fedora 17 it is possible to easily build (cross-compile) binaries for the win32 and win64 targets. This is realized using the mingw-w64 toolchain: http://mingw-w64.sf.net/. Using this toolchain allows you to build binaries for the following programming languages: C, C++, Objective-C, Objective-C++ and Fortran.
"Tips and tricks for using the Windows cross-compiler": https://fedoraproject.org/wiki/MinGW/Tips
For Fedora:
# Fedora 18 or greater
sudo dnf group install "MinGW cross-compiler"
# Or (not recommended, because of its deprecation)
sudo yum groupinstall -y "MinGW cross-compiler"