Bazel构建C++项目：Windows及跨平台链接bcrypt.lib适配Boost UUID

问题背景 #

使用Bazel开发C++应用，集成Boost UUID库时遇到以下问题：

• Windows下需链接Windows SDK中的bcrypt.lib，但当前cc_import配置会在本地目录查找库文件，导致多架构兼容问题
• 编译时出现LNK2019未解析外部符号错误，对应BCryptCloseAlgorithmProvider、BCryptGenRandom、BCryptOpenAlgorithmProvider函数

跨平台解决方案 #

Windows平台 #

要自动适配不同架构并正确指向Windows SDK中的bcrypt.lib，需通过select区分目标架构，并结合SDK路径配置：

硬编码SDK版本（适用于固定环境）

cc_import(
    name = "bcrypt",
    interface_library = select({
        "@bazel_tools//src/conditions:windows_x86_64": "C:/Program Files (x86)/Windows Kits/10/Lib/10.0.22621.0/um/x64/bcrypt.lib",
        "@bazel_tools//src/conditions:windows_x86": "C:/Program Files (x86)/Windows Kits/10/Lib/10.0.22621.0/um/x86/bcrypt.lib",
        "@bazel_tools//src/conditions:windows_arm64": "C:/Program Files (x86)/Windows Kits/10/Lib/10.0.22621.0/um/arm64/bcrypt.lib",
    }),
    system_provided = True,
)

cc_library(
    name = "your_lib",
    srcs = ["your_source.cpp"],
    deps = [
        ":bcrypt",
        "@boost//:uuid",  # 确保已引入Boost UUID依赖
    ],
)

注：替换10.0.22621.0为你实际安装的Windows SDK版本号

动态获取SDK版本（推荐，适配多环境）

通过Bazel内置工具函数自动获取SDK版本，避免硬编码：

load("@bazel_tools//tools/cpp:windows_cc_configure.bzl", "find_windows_sdk_version")

windows_sdk_version = find_windows_sdk_version()

cc_import(
    name = "bcrypt",
    interface_library = select({
        "@bazel_tools//src/conditions:windows_x86_64": "C:/Program Files (x86)/Windows Kits/10/Lib/%s/um/x64/bcrypt.lib" % windows_sdk_version,
        "@bazel_tools//src/conditions:windows_x86": "C:/Program Files (x86)/Windows Kits/10/Lib/%s/um/x86/bcrypt.lib" % windows_sdk_version,
        "@bazel_tools//src/conditions:windows_arm64": "C:/Program Files (x86)/Windows Kits/10/Lib/%s/um/arm64/bcrypt.lib" % windows_sdk_version,
    }),
    system_provided = True,
)

cc_library(
    name = "your_lib",
    srcs = ["your_source.cpp"],
    deps = [":bcrypt", "@boost//:uuid"],
)

macOS平台 #

macOS下Boost UUID的random_generator会自动调用系统随机数接口（如arc4random_buf），无需额外链接系统库，只需确保Boost UUID依赖正确：

cc_library(
    name = "your_lib",
    srcs = ["your_source.cpp"],
    deps = ["@boost//:uuid"],
)

Debian/Ubuntu等Linux平台 #

Linux下random_generator依赖OpenSSL的libcrypto库，可通过两种方式配置：

方式1：直接链接系统库

cc_library(
    name = "your_lib",
    srcs = ["your_source.cpp"],
    deps = ["@boost//:uuid"],
    linkopts = ["-lcrypto"],
)

方式2：通过Bazel依赖引入OpenSSL

若项目已集成OpenSSL的Bazel规则，直接依赖即可：

cc_library(
    name = "your_lib",
    srcs = ["your_source.cpp"],
    deps = [
        "@boost//:uuid",
        "@openssl//:crypto",
    ],
)

内容的提问来源于stack exchange，提问作者Adam