CentOS 7下的xmake如何调用SCL中的gcc？

[MIngPAPA]

CentOS 7 有一套SCL Repo来匹配高版本的gcc

# yum install -y  centos-release-scl
# yum install  -y devtoolset-8

然后通过scl enable devtoolset-8 bash 来激活gcc-8环境。

$ which gcc
/opt/rh/devtoolset-8/root/usr/bin/gcc
$ which g++
/opt/rh/devtoolset-8/root/usr/bin/g++
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/opt/rh/devtoolset-8/root/usr/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,lto --prefix=/opt/rh/devtoolset-8/root/usr --mandir=/opt/rh/devtoolset-8/root/usr/share/man --infodir=/opt/rh/devtoolset-8/root/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --with-linker-hash-style=gnu --with-default-libstdcxx-abi=gcc4-compatible --enable-plugin --enable-initfini-array --with-isl=/builddir/build/BUILD/gcc-8.3.1-20190311/obj-x86_64-redhat-linux/isl-install --disable-libmpx --enable-gnu-indirect-function --with-tune=generic --with-arch_32=x86-64 --build=x86_64-redhat-linux
Thread model: posix
gcc version 8.3.1 20190311 (Red Hat 8.3.1-3) (GCC)

xmake要如何读取此工具链？

[waruqi]

都在 path 里了，直接 xmake 不就好了么，还需要做什么。。

[MIngPAPA]

就是跑个默认的hello word。
这是xmake.lua默认的配置

$ cat xmake.lua
add_rules("mode.debug", "mode.release")

target("hello")
    set_kind("binary")
    add_files("src/*.cpp")

$ xmake  build
checking for platform ... linux
checking for architecture ... x86_64
error: target(hello): toolchain not found!

$ which g++
/opt/rh/devtoolset-8/root/usr/bin/g++

[waruqi]

执行下面的命令，给我完整 logs

xmake f -c -vD
xmake -rvD

[MIngPAPA]

感谢您的帮助😊😊 看上去调用的还是/usr/bin/gcc

$ xmake f -c -vD
checking for platform ... linux
checking for architecture ... x86_64
checking for gcc ... /usr/bin/gcc
checkinfo: runv(dmd --version) failed(127)
checking for dmd ... no
checkinfo: runv(ldc2 --version) failed(127)
checking for ldc2 ... no
checkinfo: runv(gdc --version) failed(127)
checking for gdc ... no
checkinfo: runv(zig version) failed(127)
checking for zig ... no
checkinfo: runv(zig version) failed(127)
checking for zig ... no
configure
{
    buildir = build
    mode = release
    ndk_stdcxx = true
    arch = x86_64
    kind = static
    ccache = true
    plat = linux
    host = linux
    clean = true
}

$ xmake -rvD
checking for gcc ... /usr/bin/gcc
checking for the c++ compiler (cxx) ... gcc
checking for /usr/bin/gcc ... ok
checking for flags (-fPIC) ... ok
> gcc "-fPIC"
checking for flags (-fvisibility-inlines-hidden) ... ok
> gcc "-fvisibility-inlines-hidden"
checking for flags (-O3) ... ok
> gcc "-O3"
checking for flags (-DNDEBUG) ... ok
> gcc "-DNDEBUG"
[ 25%]: cache compiling.release src/main.cpp
/usr/bin/gcc -c -m64 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG -o build/.objs/hello/linux/x86_64/release/src/main.cpp.o src/main.cpp
checking for flags (-MMD -MF) ... ok
> gcc "-MMD" "-MF" "/dev/null"
checking for flags (-fdiagnostics-color=always) ... ok
> gcc "-fdiagnostics-color=always"
checking for g++ ... /usr/bin/g++
checking for the linker (ld) ... g++
checking for /usr/bin/g++ ... ok
checking for flags (-fPIC) ... ok
> g++ "-fPIC"
[ 50%]: linking.release hello
/usr/bin/g++ -o build/linux/x86_64/release/hello build/.objs/hello/linux/x86_64/release/src/main.cpp.o -m64 -s

build cache stats:
cache directory: build/.build_cache
cache hit rate: 0%
cache hit: 0
cache miss: 1
new cached files: 1
remote cache hit: 0
remote new cached files: 0
preprocess failed: 0
compile fallback count: 0

[100%]: build ok!

$ which g++
/opt/rh/devtoolset-8/root/usr/bin/g++

[waruqi]

默认就是从 $PATH 和 $CC 里面取的，你可以改下 PATH，或者 $CC 或者 xmake f --cc= --cxx --ld= 改下

[MIngPAPA]

非常感谢！
利用这个命令解决了编译问题！
参考到了 #962

$ xmake  f --cc=$(which gcc) --cxx=$(which g++) --ld=$(which g++)
checking for platform ... linux
checking for architecture ... x86_64

 $ xmake -rvD
checking for /opt/rh/devtoolset-8/root/usr/bin/g++ ... ok
checking for flags (-fPIC) ... ok
> g++ "-fPIC"
checking for flags (-fvisibility-inlines-hidden) ... ok
> g++ "-fvisibility-inlines-hidden"
checking for flags (-O3) ... ok
> g++ "-O3"
checking for flags (-DNDEBUG) ... ok
> g++ "-DNDEBUG"
[ 25%]: cache compiling.release src/main.cpp
/opt/rh/devtoolset-8/root/usr/bin/g++ -c -m64 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -std=c++17 -DNDEBUG -o build/.objs/hello/linux/x86_64/release/src/main.cpp.o src/main.cpp
checking for flags (-MMD -MF) ... ok
> g++ "-MMD" "-MF" "/dev/null"
checking for flags (-fdiagnostics-color=always) ... ok
> g++ "-fdiagnostics-color=always"
checking for flags (-fPIC) ... ok
> g++ "-fPIC"
[ 50%]: linking.release hello
/opt/rh/devtoolset-8/root/usr/bin/g++ -o build/linux/x86_64/release/hello build/.objs/hello/linux/x86_64/release/src/main.cpp.o -m64 -s

build cache stats:
cache directory: build/.build_cache
cache hit rate: 0%
cache hit: 0
cache miss: 1
new cached files: 1
remote cache hit: 0
remote new cached files: 0
preprocess failed: 0
compile fallback count: 0

[100%]: build ok!