本篇的所有代码放在：https://github.com/backendcloud/example/tree/master/bazel-genrule
创建一个简单的 c hello 项目
代码语言：javascript复制 ⚡ root@backendcloud ~/bazel-genrule touch WORKSPACE
⚡ root@backendcloud ~/bazel-genrule more dir/*
::::::::::::::
dir/BUILD.bazel
::::::::::::::# dir/BUILDcc_binary(
name = "hello_bazel",
srcs = ["main.c"],)::::::::::::::
dir/main.c
::::::::::::::
// dir/main.c#include <stdio.h>int main(int argc, char **argv) {
printf("Hello Bazel.n");
return 0;} ⚡ root@backendcloud ~/bazel-genrule bazel run //dir:hello_bazel
INFO: Analyzed target //dir:hello_bazel (36 packages loaded, 161 targets configured).
INFO: Found 1 target...
Target //dir:hello_bazel up-to-date:
bazel-bin/dir/hello_bazel
INFO: Elapsed time: 2.158s, Critical Path: 0.08s
INFO: 6 processes: 4 internal, 2 linux-sandbox.
INFO: Build completed successfully, 6 total actions
INFO: Build completed successfully, 6 total actions
Hello Bazel.
⚡ root@backendcloud ~/bazel-genrule bazel build //dir:hello_bazel
INFO: Analyzed target //dir:hello_bazel (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
Target //dir:hello_bazel up-to-date:
bazel-bin/dir/hello_bazel
INFO: Elapsed time: 0.128s, Critical Path: 0.00s
INFO: 1 process: 1 internal.
INFO: Build completed successfully, 1 total action
⚡ root@backendcloud ~/bazel-genrule tree bazel-bin
bazel-bin
└── dir
├── hello_bazel
├── hello_bazel-2.params
├── hello_bazel.runfiles
│ ├── __main__
│ │ └── dir
│ │ └── hello_bazel -> /root/.cache/bazel/_bazel_root/ad9cc06f8fa63e04295f7fabfff7160e/execroot/__main__/bazel-out/k8-fastbuild/bin/dir/hello_bazel
│ └── MANIFEST
├── hello_bazel.runfiles_manifest
└── _objs
└── hello_bazel
├── main.pic.d
└── main.pic.o6 directories, 7 files
⚡ root@backendcloud ~/bazel-genrule cp bazel-bin/dir/hello_bazel.runfiles/__main__/dir/hello_bazel .
⚡ root@backendcloud ~/bazel-genrule ./hello_bazel
Hello Bazel.使用 genrule 执行一条命令
genrule 的 参数 分为：sources，a tool（例如一个内置命令，一个shell脚本），一条命令，outputs
代码语言：javascript复制genrule :: (name, sources, tool, command) -> output下面的例子是cp一个点c文件，再运行一个写有sed功能的脚本。
代码语言：javascript复制 ⚡ root@backendcloud ~/bazel-genrule more dir2/*
::::::::::::::
dir2/BUILD.bazel
::::::::::::::
genrule(
name = "copy_of_main",
srcs = ["main.c"],
outs = ["copy_of_main.c"],
cmd = "cp $< $@",)::::::::::::::
dir2/main.c
::::::::::::::#include <stdio.h>int main(int argc, char **argv) {
printf("Hello Blaze.n");
return 0;}< 表示 input sources main.c，
代码语言：javascript复制 ⚡ root@backendcloud ~/bazel-genrule bazel build //dir2:copy_of_main
INFO: Analyzed target //dir2:copy_of_main (2 packages loaded, 3 targets configured).
INFO: Found 1 target...
Target //dir2:copy_of_main up-to-date:
bazel-bin/dir2/copy_of_main.c
INFO: Elapsed time: 0.261s, Critical Path: 0.01s
INFO: 2 processes: 1 internal, 1 linux-sandbox.
INFO: Build completed successfully, 2 total actions
⚡ root@backendcloud ~/bazel-genrule tree bazel-bin
bazel-bin
├── dir│ ├── hello_bazel
│ ├── hello_bazel-2.params
│ ├── hello_bazel.runfiles
│ │ ├── __main__
│ │ │ └── dir│ │ │ └── hello_bazel -> /root/.cache/bazel/_bazel_root/ad9cc06f8fa63e04295f7fabfff7160e/execroot/__main__/bazel-out/k8-fastbuild/bin/dir/hello_bazel
│ │ └── MANIFEST
│ ├── hello_bazel.runfiles_manifest
│ └── _objs
│ └── hello_bazel
│ ├── main.pic.d
│ └── main.pic.o
└── dir2
└── copy_of_main.c7 directories, 8 files
⚡ root@backendcloud ~/bazel-genrule cat bazel-bin/dir2/copy_of_main.c#include <stdio.h>int main(int argc, char **argv) {
printf("Hello Blaze.n");
return 0;}代码语言：javascript复制文件成功复制。
⚡ root@backendcloud ~/bazel-genrule more dir2/*
::::::::::::::
dir2/BUILD.bazel
::::::::::::::
genrule(
name = "copy_of_main",
srcs = ["main.c"],
outs = ["copy_of_main.c"],
cmd = "cp $< $@",)genrule(
name = "renamed_main",
srcs = ["copy_of_main.c"],
outs = ["renamed_main.c"],
tools = ["substitute.sh"],
cmd = "$(location substitute.sh) 'Blaze' 'Bazel' $< $@",)::::::::::::::
dir2/main.c
::::::::::::::#include <stdio.h>int main(int argc, char **argv) {
printf("Hello Blaze.n");
return 0;}::::::::::::::
dir2/substitute.sh
::::::::::::::#!/bin/bashsed "s/$1/$2/" $3 > $4
⚡ root@backendcloud ~/bazel-genrule bazel build //dir2:renamed_main
INFO: Analyzed target //dir2:renamed_main (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
ERROR: /root/bazel-genrule/dir2/BUILD.bazel:8:8: Executing genrule //dir2:renamed_main failed: (Exit 126): bash failed: error executing command /bin/bash -c 'source external/bazel_tools/tools/genrule/genrule-setup.sh; dir2/substitute.sh '''Blaze''' '''Bazel''' bazel-out/k8-fastbuild/bin/dir2/copy_of_main.c bazel-out/k8-fastbuild/bin/dir2/renamed_main.c'Use --sandbox_debug to see verbose messages from the sandbox and retain the sandbox build root for debugging
/bin/bash: line 1: dir2/substitute.sh: Permission denied
Target //dir2:renamed_main failed to build
Use --verbose_failures to see the command lines of failed build steps.
INFO: Elapsed time: 0.104s, Critical Path: 0.01s
INFO: 2 processes: 2 internal.
FAILED: Build did NOT complete successfully上面报错是因为没有权限，赋予权限。chmod u x substitute.sh
✘ ⚡ root@backendcloud ~/bazel-genrule chmod 777 dir2/substitute.sh
⚡ root@backendcloud ~/bazel-genrule bazel build //dir2:renamed_main
INFO: Analyzed target //dir2:renamed_main (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
Target //dir2:renamed_main up-to-date:
bazel-bin/dir2/renamed_main.c
INFO: Elapsed time: 0.103s, Critical Path: 0.01s
INFO: 2 processes: 1 internal, 1 linux-sandbox.
INFO: Build completed successfully, 2 total actions
⚡ root@backendcloud ~/bazel-genrule tree bazel-bin
bazel-bin
├── dir│ ├── hello_bazel
│ ├── hello_bazel-2.params
│ ├── hello_bazel.runfiles
│ │ ├── __main__
│ │ │ └── dir│ │ │ └── hello_bazel -> /root/.cache/bazel/_bazel_root/ad9cc06f8fa63e04295f7fabfff7160e/execroot/__main__/bazel-out/k8-fastbuild/bin/dir/hello_bazel
│ │ └── MANIFEST
│ ├── hello_bazel.runfiles_manifest
│ └── _objs
│ └── hello_bazel
│ ├── main.pic.d
│ └── main.pic.o
└── dir2
├── copy_of_main.c
└── renamed_main.c7 directories, 9 files
⚡ root@backendcloud ~/bazel-genrule cat bazel-bin/dir2/renamed_main.c#include <stdio.h>int main(int argc, char **argv) {
printf("Hello Bazel.n");
return 0;}加上cc_binary，执行完成的BUILD流程：
代码语言：javascript复制 ⚡ root@backendcloud ~/bazel-genrule more dir2/*
::::::::::::::
dir2/BUILD.bazel
::::::::::::::
genrule(
name = "copy_of_main",
srcs = ["main.c"],
outs = ["copy_of_main.c"],
cmd = "cp $< $@",)genrule(
name = "renamed_main",
srcs = ["copy_of_main.c"],
outs = ["renamed_main.c"],
tools = ["substitute.sh"],
cmd = "$(location substitute.sh) 'Blaze' 'Bazel' $< $@",)cc_binary(
name = "hello_bazel",
srcs = [":renamed_main"],)::::::::::::::
dir2/main.c
::::::::::::::#include <stdio.h>int main(int argc, char **argv) {
printf("Hello Blaze.n");
return 0;}::::::::::::::
dir2/substitute.sh
::::::::::::::#!/bin/bashsed "s/$1/$2/" $3 > $4
⚡ root@backendcloud ~/bazel-genrule bazel run //dir2:hello_bazel
INFO: Analyzed target //dir2:hello_bazel (34 packages loaded, 160 targets configured).
INFO: Found 1 target...
Target //dir2:hello_bazel up-to-date:
bazel-bin/dir2/hello_bazel
INFO: Elapsed time: 0.366s, Critical Path: 0.06s
INFO: 6 processes: 4 internal, 2 linux-sandbox.
INFO: Build completed successfully, 6 total actions
INFO: Build completed successfully, 6 total actions
Hello Bazel.
