编译构建工具-bazel

• bazel是什么：
  https://zhulao.gitee.io/blog/2019/04/05/%E7%BC%96%E8%AF%91%E6%9E%84%E5%BB%BA%E5%B7%A5%E5%85%B7-bazel/index.html

• 下载和安装：
  bazel的官网下有各种版本 https://github.com/bazelbuild/bazel/releases
  

官网：
https://github.com/bazelbuild/bazel

---

• bazel编译一个最简单的项目示例

目录：
tree -L 2
├── BUILD
├── WORKSPACE
├── build.sh
├── main.cpp
└── subdirectory
    ├── BUILD
    ├── file.h
    ├── file1.cpp
    └── file2.cpp

build文件

package(default_visibility = ["//visibility:public"])

cc_library(
    name = "my_project_lib",
    srcs = [
        "main.cpp",
    ],
    deps = [
        "//subdirectory:subdirectory_lib",
    ],
)

cc_binary(
    name = "my_project",
    deps = [
        ":my_project_lib",
    ],
)

main.cpp

#include <iostream>
#include "subdirectory/file.h"

int main() {
    std::cout << "Hello, World!" << std::endl;
    printMessage1();
    printMessage2();
    return 0;
}

子目录 subdirectory/BUILD

package(default_visibility = ["//visibility:public"])

cc_library(
    name = "subdirectory_lib",
    srcs = [
        "file1.cpp",
        "file2.cpp",
    ],
    hdrs = [
        "file.h",
    ],
)

subdirectory/file1.cpp

#include <iostream>

void printMessage1() {
    std::cout << "This is file1.cpp" << std::endl;
}

subdirectory/file2.cpp

#include <iostream>

void printMessage2() {
    std::cout << "This is file2.cpp" << std::endl;
}

subdirectory/file.h

#ifndef FILE_H
#define FILE_H

void printMessage1();

void printMessage2();

#endif // FILE_H

build.sh

# build 
bazel build :my_project

---

• 查看编译依赖：
  bazel query 可以打印出依赖图，对于复杂项目，这个可以命令可以快速分析出依赖

# query 
bazel query 'deps(//:my_project)'  -k --output=build > deps.log

deps.log

#~test/bazel_repo/BUILD:13:10
cc_binary(
  name = "my_project",
  deps = ["//:my_project_lib"],
)
# Rule my_project instantiated at (most recent call last):
#  ~test/bazel_repo/BUILD:13:10 in <toplevel>

#~test/bazel_repo/BUILD:3:11
cc_library(
  name = "my_project_lib",
  deps = ["//subdirectory:subdirectory_lib"],
  srcs = ["//:main.cpp"],
)
# Rule my_project_lib instantiated at (most recent call last):
#  ~test/bazel_repo/BUILD:3:11 in <toplevel>

#~test/bazel_repo/subdirectory/BUILD:3:11
cc_library(
  name = "subdirectory_lib",
  srcs = ["//subdirectory:file1.cpp", "//subdirectory:file2.cpp"],
  hdrs = ["//subdirectory:file.h"],
)

• 编译debug版本

# debug 
bazel build :my_project -c dbg 

• 编译指定依赖库：

package(default_visibility = ["//visibility:public"])

load("//bazel:cpplint.bzl", "cpplint")
load("//bazel:build.bzl", "cc_test")

cc_library(
    name = "service",
    srcs = glob(["*.cpp"]),
    hdrs = glob(["*.h"]),
    deps = [
        "//other/framework:framework",
        "@other_proto//:other_proto",
        "@brpc",
        "@glog",
    ],
)

• 编译指定依赖公共库
  WORKSPACE文件中声明了brpc的依赖。在WORKSPACE文件中添加以下内容：

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "brpc",
    urls = ["https://github.com/apache/incubator-brpc/archive/refs/tags/0.9.7.zip"],
    strip_prefix = "incubator-brpc-0.9.7",
)

load("@brpc//:workspace.bzl", "brpc_dependencies")

brpc_dependencies()

在你的BUILD文件中，将brpc添加为my_project_lib的依赖项。修改cc_library规则如下：

cc_library(
    name = "my_project_lib",
    srcs = [
        "main.cpp",
    ],
    hdrs = [
        "//subdirectory:file.h",
    ],
    deps = [
        "//subdirectory:subdirectory_lib",
        "@brpc//:brpc",
    ],
)

• 编译协议：

proto_library(
    name = "xxxx_proto_pb",
    srcs = glob([
        "xxxx_proto_pb/*.proto",
    ]),
)

cc_proto_library(
    name = "xxx_proto",
    deps = [":xxxx_proto_pb"],
)

• 项目构建：

#!/bin/bash

set -ex

function Build() {
    main_target="//xxxx:xxxx"
    other_targets="//test/yyy:yyyy"
    bazel build ${build_args} ${main_target}
    bazel build ${build_args} ${other_targets}
}

function Move() {
    cp ./start.sh ./output/
    cp -r ./conf ./output/
    cp ./bazel-bin/xxxx ./output/
} 

# main

rm -rf ./output && mkdir ./output 

build_args="--loading_phase_threads=1 --copt="-g" --copt="-O2""
build_args=${build_args}" --remote_http_cache=xxxxx" 

Build
Move