I have been trying to compile a simple hello world program in c++ using clang. Now in the past I have been able to do this using the command:
clang -lc++ hello.cpp -o hello
When I try this I get the error:
/usr/bin/ld: cannot find -lc++
Clang: error : linker command failed with exit code 1
If I use g++ it compiles without errors. Why is this problem occurring with clang?
You need to install libc++ library.
Try if are using ubuntu:
sudo bash -c "cat >> /etc/apt/sources.list" << LLVMAPT
# LLVM
deb http://llvm.org/apt/trusty/ llvm-toolchain-trusty main
deb-src http://llvm.org/apt/trusty/ llvm-toolchain-trusty main
# 3.5
deb http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.5 main
deb-src http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.5 main
# 3.6
deb http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.6 main
deb-src http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.6 main
LLVMAPT
wget -O - http://llvm.org/apt/llvm-snapshot.gpg.key|sudo apt-key add -
sudo apt-get update -y
sudo apt-get install -y clang-3.6 lldb-3.6 libc++-dev libc++abi-dev
If the script above doesnt work or you do not use ubuntu then please check this websites to download that library:
http://libcxx.llvm.org/
http://libcxx.llvm.org/docs/BuildingLibcxx.html
Clang compiles C language and Clang++ compiles C++. Those are different languages, so you need a separate compiler for each of them.
Some time ago I was having trouble with this as well. I tried linking loads of libraries (-lstdc++ etc), building stdlib from source, etc, but nothing worked. This was a judge problem until I realized that I had to use clang++.
So you too, you need clang++, not clang.
Related
I had to downgrade my GCC to version 4.7 because I had this kind of problem when compiling matConvnet
Warning: You are using gcc version '5.4.0'. The version of gcc is not supported. The version currently supported with MEX is '4.7.x'. For a list of currently supported compilers see: http://www.mathworks.com/support/compilers/current_release.
So, I did the following steps to make GCC 4.7.0 the default compiler of my machine:
sudo apt-get install gcc-4.7
sudo rm /usr/bin/gcc
ln -s /usr/bin/gcc-4.7 /usr/bin/gcc
However, when I try to compile Matconvnet again I had the following error:
Error using vl_compilenn>mex_compile (line 434)
No supported compiler or SDK was found. For options, visit http://www.mathworks.com/support/compilers/R2016a/glnxa64.html.
Error in vl_compilenn (line 387)
parfor i = 1:numel(horzcat(lib_src, mex_src))
What I missed in my procedure?
EDIT: I realized that the problem is with the g++ compiler
when I do the mex -setup C++ command in MATLAB I have this error:
Error using mex
No supported compiler or SDK was found. For options, visit http://www.mathworks.com/support/compilers/R2016a/glnxa64.html.
When I do the which g++ command it returns me nothing. When I apt-get install g++ the following returns to me:
g++ is already the newest version (4:5.3.1-1ubuntu1).
What I can do to make MATLAB recognize my g++ compiler?
It's probably way to late for an answer, but when I had a similar problem, the following seemed to be the solution:
sudo apt-get install --reinstall gcc
sudo apt-get install --reinstall g++
Hope it helps everyone who stumbles upon this.
I've tried several solutions found on google search, but nothing seems to work. Here is a shot of my vim --version and I currently have python 2.7.5 installed:
Huge version without GUI. Features included (+) or not (-):
+arabic +file_in_path +mouse_sgr +tag_binary
+autocmd +find_in_path -mouse_sysmouse +tag_old_static
-balloon_eval +float +mouse_urxvt -tag_any_white
-browse +folding +mouse_xterm -tcl
++builtin_terms -footer +multi_byte +terminfo
+byte_offset +fork() +multi_lang +termresponse
+cindent +gettext -mzscheme +textobjects
-clientserver -hangul_input +netbeans_intg +title
-clipboard +iconv +path_extra -toolbar
+cmdline_compl +insert_expand -perl +user_commands
+cmdline_hist +jumplist +persistent_undo +vertsplit
+cmdline_info +keymap +postscript +virtualedit
+comments +langmap +printer +visual
+conceal +libcall +profile +visualextra
+cryptv +linebreak -python +viminfo
+cscope +lispindent -python3 +vreplace
+cursorbind +listcmds +quickfix +wildignore
+cursorshape +localmap +reltime +wildmenu
+dialog_con -lua +rightleft +windows
+diff +menu -ruby +writebackup
+digraphs +mksession +scrollbind -X11
-dnd +modify_fname +signs -xfontset
-ebcdic +mouse +smartindent -xim
+emacs_tags -mouseshape -sniff -xsmp
+eval +mouse_dec +startuptime -xterm_clipboard
+ex_extra -mouse_gpm +statusline -xterm_save
+extra_search -mouse_jsbterm -sun_workshop
+farsi +mouse_netterm +syntax
system vimrc file: "$VIM/vimrc"
user vimrc file: "$HOME/.vimrc"
2nd user vimrc file: "~/.vim/vimrc"
user exrc file: "$HOME/.exrc"
fall-back for $VIM: "/usr/local/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -I/usr/local/include -g - O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
Linking: gcc -L/usr/local/lib -Wl,--as-needed -o vim -lm -ltinfo - lnsl -ldl
I followed some points on this thread and it got me up and running. I think there are steps you can probably skip, but I have found this to be a working solution:
1) Remove installed vim
yum remove (all things vimish)
2) Remove other vim footprints
find / -name vim
3) Add software collection utility
yum -y install scl-utils
4) Add python repo
rpm -Uvh https://www.softwarecollections.org/en/scls/rhscl/python33/epel-7-x86_64/download/rhscl-python33-epel-7-x86_64.noarch.rpm
4) Install python
yum -y install python33
5) Install gvim
yum install gvim
6) Install vim-enhanced
yum install vim-enhanced.x86_64
7) Install sudo
yum install sudo
In vim do a :echo has('python') and it should return 1 which means you now have python support. **Please be aware that you will be uninstalling sudo if you uninstall vim-minimal. I think you should be okay if you copy your settings from visudo and repost after reinstalling sudo.
8) If the following occurs:
bash: /usr/local/bin/vim: No such file or directory
then do the following commands:
hash vim
vim
Details for this fix at this link
I am trying to link boost::asio using terminal (I'm also using a text editor).
What I tried
I did some researches on Internet (I didn't found nothing about my distro) - I found I must install that library by executing the following command on the terminal:
sudo pacman -S libboost-all-dev
This is the output I get:
error: the following package was not found: libboost-all-dev
Final question
How can I install and link correctly boost::asio with my .cpp file?
Notes:
I'm using Archlinux
To find a package in Arch Linux, do:
sudo pacman -Ss boost
This will list packages with the string boost. Or, you can look up on the package website: https://www.archlinux.org/packages/extra/x86_64/boost/
One thing you should understand about boost is that a majority of its modules are header-only; if the linker complains about undefined references then you would have to link the required files. To link boost-asio, you would do
g++ -lboost-system <source> <exe>
How to install boost in Arch Linux
You cannot link libraries inside your *.cpp files. You should enumerate required libraries using the -l option in the g++ command line.
g++ -lboos-asio -lboost-system myfile.cpp -o myapp
$ gcc 12.c -fopenmp
12.c:9:9: fatal error: 'omp.h' file not found
#include<omp.h>
^
1 error generated.
While compiling openMP programs I get the above error. I am using OS X Yosemite. I first tried by installing native gcc compiler by typing gcc in terminal and later downloaded Xcode too still I got the same error. Then I downloaded gcc through:
$ brew install gcc
Still I'm getting the same error. I did try changing the compiler path too still it shows:
$ which gcc
/usr/bin/gcc
So how do I compile programs with gcc?
EDIT: As of 13 Aug 2017 the --without-multilib option is no longer present in Homebrew and should not be used. The standard installation
brew install gcc
will provide a gcc installation that can be used to compile OpenMP programs. As below it will be installed into /usr/local/bin as gcc-<version>. The current gcc version available from Homebrew (as of writing) will install as gcc-8. You can compile programs with OpenMP support using it via
gcc-8 -fopenmp hello.c
Alternatively you could put an alias in your .bashrcfile as
alias gcc='gcc-8'
and then compile using
gcc -fopenmp hello.c
Note: I'm leaving the original post here in case it is useful to somebody.
The standard gcc available on OS X through XCode and Clang doesn't support OpenMP. To install the Homebrew version of gcc with OpenMP support you need to install it with
brew install gcc --without-multilib
or as pointed out by #Mark Setchell
brew reinstall gcc --without-multilib
This will install it to the /usr/local/bin directory. Homebrew will install it as gcc-<version> so as not to clobber the gcc bundled with XCode.
I finally did some research and I finally came across a solution here: <omp.h> library isn't found in the GCC version (4.2.1) in Mavericks.
I got a new gcc complier from http://hpc.sourceforge.net/
Then I placed a new executable folder by
$ sudo tar -xvf gcc-4.9-bin.tar -C /
Later I switched to it by
export PATH=/usr/local/bin:$PATH that seemed to do the trick!
I get the error message:
make[2]: g++: Command not found
which I know means it cannot find the C++ compiler. However, in Netbeans if I go to the configuration to choose my C++ compiler it shows the following being in /usr/bin:
g++4.6
g++4.7
g++4.8
but it doesn't have just g++.
Tried sudo aptitude install g++ but it didnt work.
If I do g++ --version I get:
The program 'g++' can be found in the following packages:
* g++
* pentium-builder
1) Verify you can run "g++" from the command line,
2) type whereis g++ to get the path,
3) Make sure you have the NetBeans C++ plugin installed
Go to Tools->Options->C++->Build Tools
4) Configure the path in NetBeans
Usually, /usr/bin/g++ is a symlink to some /usr/bin/g++-4.7 (or g++-4.8 etc...); just make it again (which is usually provided by the g++ virtual package on Debian or Ubuntu), e.g.
% sudo -s
# cd /usr/bin
# ln -sv g++-4.8 g++
Above % and # are shell prompts that you should not type.
Of course, don't forget the sudo apt-get install g++ etc...
BTW, you might put that link from $HOME/bin/g++ to /usr/bin/g++-4.8 and you don't need root permission for that.
(sometimes, these symlinks go indirectly thru /etc/alternatives etc...)
Your issue is a sysadmin issue; you should rather ask it (with a big lot more details) on askubuntu or superuser; it is off-topic on Stack Overflow.
BTW, NetBeans is not a compiler, but an editor (sometimes called IDE). You could use something better/simpler (e.g. emacs or vim) with e.g. make as a builder (to be run inside a terminal). Before using NetBeans ensure that g++ -v is working alone in some terminal