Mac OS系统下升级gcc后切换

1、brew search gcc 查看已安装和可安装的gcc版本

(base)  ~  brew search gcc
Warning: Error searching on GitHub: curl failed!   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                Dload  Upload   Total   Spent    Left  Speed
 0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
curl: (35) LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to api.github.com:443

==> Formulae
gcc ✔            gcc@4.9 ✔        gcc@5            gcc@6            gcc@7 ✔          gcc@8            x86_64-elf-gcc
==> Casks
gcc-arm-embedded

2、 brew install gcc@7 安装相应版本的gcc

​ brew cask install gcc-arm-embedded 安装相应版本的arm版本gcc

3、切换gcc版本

修改gcc版本

修改环境变量：~/.bash_profile；在文件末尾添加三句话

alias gcc="gcc-7"  

alias cc="gcc-7" 

alias g++="g++-7"

alias c++="c++-7"

4、arm-gcc命令

命令行输入： arm-none-eabi-gcc -v ,查看相关命令

Using built-in specs.
COLLECT_GCC=arm-none-eabi-gcc
COLLECT_LTO_WRAPPER=/usr/local/Caskroom/gcc-arm-embedded/9-2019-q4-major/gcc-arm-none-eabi-9-2019-q4-major/bin/../lib/gcc/arm-none-eabi/9.2.1/lto-wrapper
Target: arm-none-eabi
Configured with: /tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/src/gcc/configure --target=arm-none-eabi --prefix=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/install-native --libexecdir=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/install-native/lib --infodir=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/install-native/share/doc/gcc-arm-none-eabi/info --mandir=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/install-native/share/doc/gcc-arm-none-eabi/man --htmldir=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/install-native/share/doc/gcc-arm-none-eabi/html --pdfdir=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/install-native/share/doc/gcc-arm-none-eabi/pdf --enable-languages=c,c++ --enable-plugins --disable-decimal-float --disable-libffi --disable-libgomp --disable-libmudflap --disable-libquadmath --disable-libssp --disable-libstdcxx-pch --disable-nls --disable-shared --disable-threads --disable-tls --with-gnu-as --with-gnu-ld --with-newlib --with-headers=yes --with-python-dir=share/gcc-arm-none-eabi --with-sysroot=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/install-native/arm-none-eabi --build=x86_64-apple-darwin10 --host=x86_64-apple-darwin10 --with-gmp=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/build-native/host-libs/usr --with-mpfr=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/build-native/host-libs/usr --with-mpc=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/build-native/host-libs/usr --with-isl=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/build-native/host-libs/usr --with-libelf=/tmp/jenkins-GCC-9-pipeline-100_20191030_1572397548/build-native/host-libs/usr --with-host-libstdcxx='-static-libgcc -Wl,-lstdc++ -lm' --with-pkgversion='GNU Tools for Arm Embedded Processors 9-2019-q4-major' --with-multilib-list=rmprofile
Thread model: single
gcc version 9.2.1 20191025 (release) [ARM/arm-9-branch revision 277599] (GNU Tools for Arm Embedded Processors 9-2019-q4-major)