Gin实践 番外 Golang交叉编译

项目地址:https://github.com/EDDYCJY/go… (快上车,支持一波)

原文地址:Golang交叉编译

前言

连载九 讲解构建Scratch镜像时,我们编译可执行文件用了另外一个形式的命令,不知道你有没有疑问?

$ CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o go-gin-example .

说明

我们将讲解命令各个参数的作用,希望你在阅读时,将每一项串联起来,你会发现这就是交叉编译相关的小知识

也就是 Golang 令人心动的特性之一跨平台编译

一、CGO_ENABLED

作用:

用于标识(声明) cgo 工具是否可用

意义:

存在交叉编译的情况时,cgo 工具是不可用的。在标准go命令的上下文环境中,交叉编译意味着程序构建环境的目标计算架构的标识与程序运行环境的目标计算架构的标识不同,或者程序构建环境的目标操作系统的标识与程序运行环境的目标操作系统的标识不同

小结:

结合案例来说,我们是在宿主机编译的可执行文件,而在 Scratch 镜像运行的可执行文件;显然两者的计算机架构、运行环境标识你无法确定它是否一致(毕竟构建的 docker 镜像还可以给他人使用),那么我们就要进行交叉编译,而交叉编译不支持 cgo,因此这里要禁用掉它

关闭 cgo 后,在构建过程中会忽略 cgo 并静态链接所有的依赖库,而开启 cgo 后,方式将转为动态链接

补充:

golang 是默认开启 cgo 工具的,可执行 go env 命令查看

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/root/.cache/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
...
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
...

二、GOOS

用于标识(声明)程序构建环境的目标操作系统

如:

  • linux
  • windows

三、GOARCH

用于标识(声明)程序构建环境的目标计算架构

若不设置,默认值与程序运行环境的目标计算架构一致(案例就是采用的默认值)

如:

  • amd64
  • 386
系统GOOSGOARCH
Windows 32位windows386
Windows 64位windowsamd64
OS X 32位darwin386
OS X 64位darwinamd64
Linux 32位linux386
Linux 64位linuxamd64

四、GOHOSTOS

用于标识(声明)程序运行环境的目标操作系统

五、GOHOSTARCH

用于标识(声明)程序运行环境的目标计算架构

六、go build

-a

强制重新编译,简单来说,就是不利用缓存或已编译好的部分文件,直接所有包都是最新的代码重新编译和关联

-installsuffix

作用:

在软件包安装的目录中增加后缀标识,以保持输出与默认版本分开

补充:

如果使用 -race 标识,则后缀就会默认设置为 -race 标识,用于区别 race 和普通的版本

-o

指定编译后的可执行文件名称

小结

大部分参数指令,都有一定关联性,且与交叉编译的知识点相关,可以好好品味一下

最后可以看看 go build help 加深了解

$ go help build
usage: go build [-o output] [-i] [build flags] [packages]
...
    -a
        force rebuilding of packages that are already up-to-date.
    -n
        print the commands but do not run them.
    -p n
        the number of programs, such as build commands or
        test binaries, that can be run in parallel.
        The default is the number of CPUs available.
    -race
        enable data race detection.
        Supported only on linux/amd64, freebsd/amd64, darwin/amd64 and windows/amd64.
    -msan
        enable interoperation with memory sanitizer.
        Supported only on linux/amd64,
        and only with Clang/LLVM as the host C compiler.
    -v
        print the names of packages as they are compiled.
    -work
        print the name of the temporary work directory and
        do not delete it when exiting.
    -x
        print the commands.

    -asmflags '[pattern=]arg list'
        arguments to pass on each go tool asm invocation.
    -buildmode mode
        build mode to use. See 'go help buildmode' for more.
    -compiler name
        name of compiler to use, as in runtime.Compiler (gccgo or gc).
    -gccgoflags '[pattern=]arg list'
        arguments to pass on each gccgo compiler/linker invocation.
    -gcflags '[pattern=]arg list'
        arguments to pass on each go tool compile invocation.
    -installsuffix suffix
        a suffix to use in the name of the package installation directory,
        in order to keep output separate from default builds.
        If using the -race flag, the install suffix is automatically set to race
        or, if set explicitly, has _race appended to it. Likewise for the -msan
        flag. Using a -buildmode option that requires non-default compile flags
        has a similar effect.
    -ldflags '[pattern=]arg list'
        arguments to pass on each go tool link invocation.
    -linkshared
        link against shared libraries previously created with
        -buildmode=shared.
    -pkgdir dir
        install and load all packages from dir instead of the usual locations.
        For example, when building with a non-standard configuration,
        use -pkgdir to keep generated packages in a separate location.
    -tags 'tag list'
        a space-separated list of build tags to consider satisfied during the
        build. For more information about build tags, see the description of
        build constraints in the documentation for the go/build package.
    -toolexec 'cmd args'
        a program to use to invoke toolchain programs like vet and asm.
        For example, instead of running asm, the go command will run
        'cmd args /path/to/asm <arguments for asm>'.
...

参考

本系列示例代码

本系列目录

书籍

  • Go并发编程实战 第二版
    原文作者:煎鱼
    原文地址: https://segmentfault.com/a/1190000013989448
    本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
点赞