What version of LLVM does the latest emscripten use?
I googled for this quite a while but could not find any info. The background is that I've got some C++ code that requires clang-5.0 - what are the chances that it would compile with emscripten? Or at least code that needs clang-4.0?
The latest version of emscripten uses clang version 4:
$ emcc -v
emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 1.37.21
clang version 4.0.0 (https://github.com/kripken/emscripten-fastcomp-clang.git 974b55fd84ca447c4297fc3b00cefb6394571d18) (https://github.com/kripken/emscripten-fastcomp.git 087c6b7b18b7b769d4ad8f2ac3e0dd0ae6b924c2) (emscripten 1.37.21 : 1.37.21)
Target: x86_64-apple-darwin16.7.0
Thread model: posix
However, you can build WebAssembly without emscripten, by using the clang, llc, s2wasm and wasm tools separately as documented in this gist.
Another good alternative is the wasm-toolchain project:
https://github.com/tpimh/wasm-toolchain
With this installed, I have clang version 6:
$ ./clang --version
clang version 6.0.0 (http://llvm.org/git/clang.git 9411957410813aeefc1bb299abcb856ce1ef8aae) (http://llvm.org/git/llvm.git 68b21d6108df63d65d6735e9686d53cca844e37a)
Target: x86_64-apple-darwin16.7.0
Thread model: posix
Related
I'm trying to install Riak from source on macOS (https://docs.riak.com/riak/kv/2.2.3/setup/installing/mac-osx.1.html#installing-from-source).
There is a note:
Riak will not compile with Clang. Please make sure that your default
C/C++ compiler is GCC
How do I find out which compiler is the default and how to change it?
macOS Catalina (10.15.4), which command prints:
$ which clang
/usr/bin/clang
$ which gcc
/usr/bin/gcc
On macOS Catalina (and prior versions, and most likely subsequent versions too), there are two aspects to the problem and some suggested solutions.
What is the name of the compiler used by make by default?
$ mkdir junk
$ cd junk
$ > x.cpp
$ > y.c
$ make x y
c++ x.cpp -o x
cc y.c -o y
$ cd ..
$ rm -fr junk
This shows that the names used by make are cc and c++. Those are not obviously clang or clang++, but neither are they obviously gcc and g++.
$ which cc c++
/usr/bin/cc
/usr/bin/c++
$
Which compiler is it really?
Which compiler really lives behind the names cc, c++, gcc, g++, clang, and clang++? We can check which compiler these really are by getting them to identify their version:
$ for compiler in cc c++ gcc g++ clang clang++
> do
> which $compiler
> $compiler --version
> done
/usr/bin/cc
Apple clang version 11.0.0 (clang-1100.0.33.17)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
/usr/bin/c++
Apple clang version 11.0.0 (clang-1100.0.33.17)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
/usr/bin/gcc
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple clang version 11.0.0 (clang-1100.0.33.17)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
/usr/bin/g++
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple clang version 11.0.0 (clang-1100.0.33.17)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
/usr/bin/clang
Apple clang version 11.0.0 (clang-1100.0.33.17)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
/usr/bin/clang++
Apple clang version 11.0.0 (clang-1100.0.33.17)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
$
As you can see, the versions installed in /usr/bin are all the same compiler, and that compiler is clang or clang++.
This was run on a machine with macOS Mojave 10.14.6 and XCode 11.3.1. The latest version of XCode — 11.4.1 — is only available on Catalina. However, the general conclusion is the same — all the C and C++ compilers are really clang and clang++ in disguise.
How do you get GNU GCC onto your machine?
How do you get a real GNU GCC — a real GCC, not clang in disguise — onto your machine?
Use Brew to install GCC (I've not checked which version of GCC is current).
Or use MacPorts (again, I've not checked which version of GCC is current).
If you're adventuresome, do it yourself (but I've not yet succeeded at building GCC 9.3.0 on Catalina; I have a GCC 9.2.0 built on macOS Mojave 10.14.x that works OK on Catalina though — with one environment variable needed to locate the headers).
Maybe Fink — it lists GCC 8.4 as being made available in 2020; I don't know about newer versions.
Be aware that Apple has taken to hiding the system header files miles out of the way (not in /usr/include — and you can't modify that part of the file system to add a symlink to where they've hidden them):
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include
(You mean you couldn't guess that? Me neither!)
How do you change the default compiler?
Once you have GCC installed somewhere appropriate, you need to ensure you use the 'real' GCC and not the 'fake' in /usr/bin. You do that in part by ensuring that the bin directory for the 'real' GCC occurs on your PATH before /usr/bin. I have GCC 9.3.0 installed under /opt/gcc/v9.3.0, so /opt/gcc/v9.3.0/bin appears on my PATH long before /usr/bin does.
You also need to ensure that the configuration for riak (the software you're installing) uses the correct compilers. If there's a ./configure script, run it with the correct path specified for the compilers. For example, I might use:
./configure CC=/opt/gcc/v9.3.0/bin/gcc CXX=/opt/gcc/v9.3.0/bin/g++
You can also set these values as environment variables.
If it uses cmake or some other configuration package, you'll need to consult the installation instructions. That's usually README or sometimes INSTALL.
See also (increasingly older posts):
Can't compile a C program on a Mac after upgrade to Catalina
Can't compile a C program on a Mac after upgrade to Mojave
Install GNU GCC on a Mac
I'm running max os x 10.11.6 and want to include openmp in my programs, meaning compile with -fopenmp which is giving me the error:
clang: error: unsupported option '-fopenmp'
clan --version is giving me:
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
According to
https://clang-omp.github.io/
clang supports openmp from version 3.7 onwards.
My first question is how does "clang-800.0.42.1" relate to "clang 3.7", so do I actually have open mp support?
My second question is, according to this simple example:
http://blog.llvm.org/2015/05/openmp-support_22.html
I have to tell clang where the omp header files and libs are located as well as add the libs to DYLD_LIBRARY_PATH. But what are the files and libs exactly called and where can I find them? I'm running default xcode without any homebrew/special compiler stuff installed.
Thx for the help!
I tried upgrading to El-Capitan and Xcode 7.0 and now gfortran doesn't work. Everytime I run gfortran, I get errors which google search doesn't seem to resolve so I'm asking stack overflow:
I'm trying to compile a minimal example program:
program hello
print *, "Hello World"
end program hello
When I run gfortran test.f
gfortran: warning: couldn’t understand kern.osversion ‘15.0.0
ld: library not found for -lgcc_s.10.4
collect2: error: ld returned 1 exit status
I'm not worried about the warning but the error of the ld is what's really bothering me. There's libgcc_s.10.4.tbd in the /usr/lib folder but it seems not be used by gfortran.
Can anyone help me resolve this as I would like to use gfortran for compiling some libraries?
MORE info: running gfortran -v outputs
gfortran: warning: couldn’t understand kern.osversion ‘15.0.0
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-apple-darwin12.2.0/4.8.0/lto-wrapper
Target: x86_64-apple-darwin12.2.0
Configured with: ../gcc-4.8-20120930/configure --enable languages=c++,fortran
Thread model: posix
gcc version 4.8.0 20120930 (experimental) (GCC)
The version of gfortran you have (4.8 installed into /usr/local) is not a version of GCC that apple would have distributed with Xcode (afaik they never made it to a version of GCC that new before switching to llvm, which has no Fortran front-end. The version of gcc distributed with Xcode 7 on el capitan identifies itself as:
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 7.0.0 (clang-700.0.72)
Target: x86_64-apple-darwin15.0.0
Thread model: posix
Your version came from somewhere else and is old enough to not know the x86_64-apple-darwin15.0.0 target. You'll need to update that compiler to get a working gfortran. Both macports and homebrew provide easy installations of various versions of gcc/gfortran on OS X el capitan, and I'd recommend using one of those to install gcc. Alternatively you can track down whatever you used to install gcc 4.8 before and see if they provide an update for el capitan.
According to the documentation, clang supports options to emit optimisation reports:
When the pass makes a transformation (-Rpass).
When the pass fails to make a transformation (-Rpass-missed).
When the pass determines whether or not to make a transformation (-Rpass-analysis).
They provide the following example command line:
$ clang -O2 -Rpass=inline code.cc -o code
When I try this, I get an error:
$ clang src/test/tests.cpp -Rpass=inline
clang: error: unknown argument: '-Rpass=inline'
scons: *** [build/test/tests.o] Error 1
scons: building terminated because of errors.
My clang version is:
$ clang --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
Is this option not available on Mac OS? Is the documentation erroneous? Or am I doing it wrong? If so, how to do it right?
Works for Debian clang-3.5.0-6, so this is probably Apple clang restriction.
% clang++ -O2 -Rpass=inline foo.cpp
foo.cpp:11:2: remark: _ZN1CC2Ev inlined into main [-Rpass=inline]
P* p = new C();
^
% clang --version
Debian clang version 3.5.0-6 (tags/RELEASE_350/final) (based on LLVM 3.5.0)
Target: i386-pc-linux-gnu
Thread model: posix
Originally, I used clang++ with -std=c++11 compile my C++11 code, everything was OK. Recently, I updated the Xcode in AppStore, I compiled the SAME program in command line again, it doesn't work anymore, it shows errors like below:
/usr/include/c++/4.2.1/bits/stl_construct.h:81:38: error: no matching
constructor for initialization of
'std::basic_string'
::new(static_cast(__p)) T1(_value);
It seems the clang++ is using gcc's header files, apparently, gcc's version is very old. However, if I compile the same program by using Xcode, everything is fine.
It seems, at command line , the clang++ can't find the correct header files anymore.
More information, running command clang++ --version, following output:
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin12.5.0 Thread model: posix
which clang++
/usr/bin/clang++
RESOLVED with option -stdlib=libc++