I'm using the Bochs emulator and for my class we're using gcc 4.2.1. I believe I've gotten Bochs running, but now I need to compile our programs which are compatible with gcc 4.2/.1.
I understand OSX uses an alias for gcc 4.2.1, but how can I use gcc specifically and not clang?
Edit: GCC 4.6.3 not 4.2.1 sorry
You can install previous version of gcc pretty easily using homebrew.
If you have homebrew installed you can get gcc 4.9 by running
brew install gcc#4.9
After it is installed gcc will still map to the clang that came with your mac. The newly installed gcc will be installed at /usr/local/bin and be called something like gcc-4.
You can find the exact executable name using
ls /usr/local/bin | grep gcc
Hopefully 4.9 is close enough to 4.6 for your purposes.
I've already visited the following answer but my question is different.
Install GNU GCC on mac
Mac OS ships with Clang and somehow /usr/bin/gcc is linked to Clang tool I assume because of this line.
gcc
clang: error: no input files
Any idea on how can I install https://gcc.gnu.org/ standalone on my system?
gcc --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk/usr/include/c++/4.2.1
Apple LLVM version 9.0.0 (clang-900.0.38)
Target: x86_64-apple-darwin17.2.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
Any idea on how can I install https://gcc.gnu.org/ standalone on my system?
Generally speaking: Don't. That isn't a standard configuration; Clang is the recommended compiler for current macOS systems.
If you have a very good reason, you can use Homebrew to install GCC (brew install gcc). Keep in mind that it cannot be used to build native macOS applications.
I currently have gcc (Ubuntu 5.2.1-22ubuntu2) 5.2.1 20151010. For some reason I have to install gcc (GCC) 4.4.7 20120313. How Can I do this?
Thanks.
gcc versions can coexists, you don't need to uninstall the system one.
try apt-get install gcc-4.7
After installing you'll need to change your makefile or your env to point to the proper tool chain instead of default gcc
You should visit https://www.gnu.org/software/gcc/gcc-4.4/ to search for the version you want.
https://www.gnu.org/software/gcc/mirrors.html
has a list of mirrors where you can download the source files for whichever version you want. You can then easily build it yourself.
Note that the version you need is GCC 4.4.7 and NOT GCC 4.7.
I'm new to Homebrew (I usually use Macports, but I'm trying out Homebrew on a 2nd computer), and I wish to install the openmpi (or mpich2) package. Steps are as follows (carried out on Mac OS X Yosemite with Xcode 6 installed):
brew install gcc
brew install openmpi
However, I suspect the linking may have been done incorrectly, due to the following reasons:
The symbolic link for /usr/local/bin/gcc is missing:
$ which gcc
/usr/bin/gcc
$ gcc --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/c++/4.2.1
Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin14.0.0
Thread model: posix
$ which gcc-4.9
/usr/local/bin/gcc-4.9
$ gcc-4.9 --version
gcc-4.9 (Homebrew gcc 4.9.2) 4.9.2
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
mpicc may have been linked to the Apple gcc:
$ which mpicc
/usr/local/bin/mpicc
$ mpicc --version
Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin14.0.0
Thread model: posix
My questions are as follows:
How do I get the /usr/local/bin/gcc symbolic link? Or is Homebrew deliberately avoiding this for certain reasons? e.g. if Homebrew is compiling all its packages using Apple gcc, which is assumed to be in the path, would changing the path to gcc-4.9 mean that Homebrew now compiles its packages with gcc-4.9 instead?
Is the Homebrew-installed Open MPI linked to the Apple gcc (and not the Homebrew gcc)? If yes, is it possible (or advisable) to change the linking?
Alternatively, how necessary is it to fix the linkages? Could I run into certain problems if I choose not to fix it? For example, I'm considering using ln -s to forcibly create the /usr/local/bin/gcc symbolic link. But is this a good idea (*)?
(*) I understand there are likely to be issues when linking object files created by different compilers. So with (1), (2) and (3), I'm hoping to find a solution that avoids combinations whereby I'm creating object files with different compilers (some with gcc-4.9 and some with the Apple gcc).
You need to do the following:
1) Add environment variables for homebrew (you can also add these lines to your ~\.bashrc):
$ export HOMEBREW_CC=gcc-4.9
$ export HOMEBREW_CXX=g++-4.9
2) Rebuild and reinstall openmpi and its dependencies from source
$ brew reinstall openmpi --build-from-source
3) In the end you will get a message like:
==> Reinstalling open-mpi
==> Using Homebrew-provided fortran compiler.
This may be changed by setting the FC environment variable.
==> Downloading http://www.open-mpi.org/software/ompi/v1.8/downloads/openmpi-1.8.
Already downloaded: /Library/Caches/Homebrew/open-mpi-1.8.4.tar.bz2
==> ./configure --prefix=/usr/local/Cellar/open-mpi/1.8.4 --disable-silent-rules
==> make all
==> make check
==> make install
Warning: open-mpi dependency gcc was built with a different C++ standard
library (libstdc++ from clang). This may cause problems at runtime.
🍺 /usr/local/Cellar/open-mpi/1.8.4: 785 files, 23M, built in 41.2 minutes
$ mpicc --showme
gcc-4.9 -I/usr/local/Cellar/open-mpi/1.8.4/include -L/usr/local/opt/libevent/lib -L/usr/local/Cellar/open-mpi/1.8.4/lib -lmpi
On my MacBook I had some conflicts with XCode 6.2, which were solved following this instructions
If you want to install mpich
$ unlink openmpi
$ brew unlink gcc
$ brew install homebrew/versions/gcc5
$ brew install mpich --build-from-source
$ mpicc -v
mpicc for MPICH version 3.2
Using built-in specs.
COLLECT_GCC=gcc-5
COLLECT_LTO_WRAPPER=/usr/local/Cellar/gcc5/5.4.0/libexec/gcc/x86_64-apple-darwin14.5.0/5.4.0/lto-wrapper
Target: x86_64-apple-darwin14.5.0
Configured with: ../configure --build=x86_64-apple-darwin14.5.0 --prefix=/usr/local/Cellar/gcc5/5.4.0 --libdir=/usr/local/Cellar/gcc5/5.4.0/lib/gcc/5 --enable-languages=c,c++,objc,obj-c++,fortran --program-suffix=-5 --with-gmp=/usr/local/opt/gmp --with-mpfr=/usr/local/opt/mpfr --with-mpc=/usr/local/opt/libmpc --with-isl=/usr/local/opt/isl014 --with-system-zlib --enable-libstdcxx-time=yes --enable-stage1-checking --enable-checking=release --enable-lto --disable-werror --with-pkgversion='Homebrew gcc5 5.4.0' --with-bugurl=https://github.com/Homebrew/homebrew-versions/issues --enable-plugin --disable-nls --enable-multilib
Thread model: posix
gcc version 5.4.0 (Homebrew gcc5 5.4.0)
It would probably be cleaner if you simply modify the configuration file for the Open MPI compiler wrapper and make it invoke gcc-4.9 instead of simply gcc. As I have no idea where exactly Homebrew puts Open MPI and therefore cannot give you the correct path directly, you should search for it:
$ find /usr/local -name mpicc-wrapper-data.txt
Once you have found mpicc-wrapper-data.txt, find the line that starts with compiler= and modify it to read:
compiler=gcc-4.9
You should also modify all other files that match the shell glob mpi*-wrapper-data.txt and modify the compiler=... line accordingly. Use g++-4.9 in mpic++, mpicxx, and mpiCC. Use gfortran-4.9 (if installed) in mpif77 and mpif90 (for Open MPI versions < 1.8) or for mpifort (for versions >= 1.8).
Mixing object code produced by different compilers on the same platform should be fine as long as all of them adhere to the same ABI, which is more or less the case with Clang and GCC. In the end, all programs are linked against the system libraries that come with OS X and those are compiled with Clang only.
When I enter
brew install gcc49
I see:
Warning: gcc49-4.9.0 already installed
and when I check my gcc version with gcc -v
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 5.1 (clang-503.0.38) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin12.5.0
Thread model: posix
Is there something else I have to do besides install gcc49 via homebrew to be able to use it?