<omp.h> library isn't found in the GCC version (4.2.1) in Mavericks

问题

I have a problem with GCC. I want to update it to a new version, from the 4.2.1, to program with parallel programming. However, in this version there is no library . How can I download an updated version?

The error that the terminal give me is:

omp_hello.c:11:10: fatal error: 'omp.h' file not found
#include <omp.h>
         ^
1 error generated.

回答1:

1. download gcc-4.9-bin.tar.gz download or newer from http://hpc.sourceforge.net/: http://prdownloads.sourceforge.net/hpc/gcc-4.9-bin.tar.gz

2. cd to your downloads folder and un-gzip the archive gunzip gcc-4.9-bin.tar.gz (Google Chrome would do that automatically)

3. in the same folder run sudo tar -xvf gcc-4.9-bin.tar -C / - this will place new executable to /usr/local/bin

4. add the following to ~/.bash_profile: export PATH=/usr/local/bin:$PATH

5. open new terminal and run which gcc. This should point to /usr/local/bin/gcc

回答2:

I got this message when I tried to reinstall GCC via Homebrew.

GCC has been built with multilib support. Notably, OpenMP may not work: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60670

If you need OpenMP support you may want to brew reinstall gcc --without-multilib

So, if you have Homebrew installed, you could try (on the terminal):

brew reinstall gcc --without-multilib

This process may take a while !

回答3:

According to this thread on apple's forums, try using gcc-4.9-bin.tar .

First install the gcc-4.9 and type "xcode-select --install" on your terminal.

Then, use "/usr/local/bin/gcc " as compiler.

回答4:

I solve it just adding aliases to .bash_profile

# Aliases in order to use brew gcc
alias gcc='gcc-5'
alias cc='gcc-5'
alias g++='g++-5'
alias c++='c++-5'

来源：https://stackoverflow.com/questions/20340117/omp-h-library-isnt-found-in-the-gcc-version-4-2-1-in-mavericks