我正在尝试在我的 C++11 代码中使用一些 OpenMP 多线程功能，例如:
#pragma omp parallel for
当我尝试编译时:
clang++ -std=c++11 -stdlib=libc++ -fopenmp main.cpp -o main.o
我收到以下错误:
clang: error: unsupported option '-fopenmp'
我也尝试使用以下方法进行编译:
g++ -fopenmp main.cpp -o main.o
但这给出了完全相同的错误。
如果您能告知我如何在 Mac OS 10.12 上编译具有 OpenMP 功能的 C++11 代码，将不胜感激。此处和其他地方的帖子上的其他问题解释了为 OpenMP 编译 C 代码，但是，我找不到 C++11 的任何内容。
我在尝试安装 libiomp 时收到错误消息:
$ brew install libiomp
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/core).
==> Updated Formulae
ansible-cmdb djview4 khard oysttyer shyaml yazpp
asciinema2gif doctl macvim pazpar2 vala you-get
avro-c elixir mailhog python vdirsyncer youtube-dl
bash-git-prompt file-roller meson python3 vim
commandbox glib metaproxy rtv x265
consul-backinator gtkextra offlineimap s-search xonsh
Error: Could not link:
/usr/local/share/doc/homebrew
Please delete these paths and run `brew update`.
Error: Could not link:
/usr/local/share/man/man1/brew.1
Please delete these paths and run `brew update`.
Error: No available formula with the name "libiomp"
==> Searching for similarly named formulae...
Error: No similarly named formulae found.
==> Searching taps...
Error: No formulae found in taps.
如果我使用 g++-6 运行，基于 Mark Setchell 在下面的帖子，它可以正常工作，谢谢，但是我收到以下警告，希望有任何关于如何避免这些警告的建议:
$ /usr/local/bin/g++-6 -std=c++11 -fopenmp main.cpp -o main.o
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:4:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:4:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:89:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:89:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:551:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:551:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:1432:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:1432:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:1799:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:1799:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:1995:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:1995:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2033:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2033:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2425:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2425:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2559:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2559:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2597:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2597:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2672:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2672:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2837:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2837:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2962:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:2962:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:3139:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:3139:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:3442:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:3442:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:3588:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:3588:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:3630:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:3630:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:5253:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:5253:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:5452:11: warning: section "__textcoal_nt" is deprecated
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/jr/30r6h4cj4tl48q_cg9bt5f5h0000gn/T//ccq73Zfg.s:5452:11: note: change section name to "__text"
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
最佳答案
更新答案
自从我在下面给出最初的回答后，情况有所改善，您可以轻松地将 OpenMP 与 clang++ 编译器一起使用 - 好啊!
为此，首先使用 homebrew 安装 brew install libomp:
brew install libomp
然后在使用 clang++ 时，使用这些标志:
clang++ -Xpreprocessor -fopenmp main.cpp -o main -lomp
原答案
如果你想在 OSX 上编译 C++11 OpenMP 代码，最简单的方法是使用 gcc，你可以通过 homebrew 安装它。
首先，检查可用的选项:
brew options gcc
样本输出
--with-all-languages
Enable all compilers and languages, except Ada
--with-java
Build the gcj compiler
--with-jit
Build the jit compiler
--with-nls
Build with native language support (localization)
--without-fortran
Build without the gfortran compiler
--without-multilib
Build without multilib support
--HEAD
Install HEAD version
所以，我怀疑你想要:
brew install gcc --without-multilib --without-fortran
安装后，您需要确保您使用的是 homebrew 版本，而不是 Apple 提供的版本。您需要知道 homebrew 将所有内容安装在 /usr/local/bin 中，并且 C++ 编译器是 g++-6。所以，你要么需要编译:
/usr/local/bin/g++-6 -std=c++11 -fopenmp main.cpp -o main
或者，在您的登录配置文件中设置您的 PATH:
export PATH=/usr/local/bin:$PATH
那么你可以这样做:
g++-6 -std=c++11 -fopenmp ...
请注意，如果您选择上面的第二个选项(即 export PATH=... 选项)，您还需要在您的当前 session 一次即可激活它，或者注销并重新登录，因为您的配置文件命令仅在登录时执行。
AFAIK，不需要显式安装 libiomp - 不知道你为什么这样做。
关于c++ - 在 Mac OS 上使用 OpenMP 和 C++11，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39979836/