Use Gcc on Macos

strong suggest install gcc with macport .

use HomeBrew maybe miss some headers.

first need install macport

also need xcode

xcode-select --install

install gcc

sudo port install gcc@13

select gcc as default compiler on macos

sudo port select --set gcc mp-gcc13

now you can check if the gcc is your.

gcc --version

which gcc

for CMAKE

also need set CC and CXX that Cmake need them to detect .

1. set CC and CXX in your shell env.

    export CC=/opt/local/bin/gcc-mp-13
    export CXX=/opt/local/bin/g++-mp-13
    export CMAKE_C_COMPILER=/opt/local/bin/gcc-mp-13
    export CMAKE_CXX_COMPILER=/opt/local/bin/g++-mp-13
   

2. set CC and CXX in your CMakeLists.txt

set(CMAKE_C_COMPILER /opt/local/bin/gcc-mp-13)
set(CMAKE_CXX_COMPILER /opt/local/bin/g++-mp-13)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -stdlib=libc++")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -stdlib=libc++")
set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -stdlib=libc++")