如何修改Bazel工具链自动生成.bin与.hex文件？

核心问题修正 #

你之前错误关联了Objective-C的ACTION_NAMES，这和C/C++的链接后动作无关，正确的思路是通过自定义动作配置+Feature，让Bazel在链接完成后自动调用objcopy生成目标文件。

具体实现步骤 #

1. 在toolchain_config.bzl中添加objcopy动作配置

导入必要模块后，定义生成.bin和.hex的动作配置：

load("@bazel_tools//tools/build_defs/cc:action_names.bzl", "ACTION_NAMES")
load("@bazel_tools//tools/cpp:cc_toolchain_config_lib.bzl", "action_config", "feature", "flag_group", "flag_set", "tool_path")

# 定义生成bin文件的objcopy动作
def _objcopy_bin_action():
    return action_config(
        name = "objcopy_bin",
        action_name = "objcopy_bin",
        tools = [":objcopy"],  # 对应你在tool_path中定义的objcopy工具名
        flag_sets = [
            flag_set(
                flags = [
                    "-O", "binary",
                    "%{input}", "%{output}",
                ],
                inputs = ["%{input}"],
                outputs = ["%{output}"],
            ),
        ],
    )

# 定义生成hex文件的objcopy动作
def _objcopy_hex_action():
    return action_config(
        name = "objcopy_hex",
        action_name = "objcopy_hex",
        tools = [":objcopy"],
        flag_sets = [
            flag_set(
                flags = [
                    "-O", "ihex",
                    "%{input}", "%{output}",
                ],
                inputs = ["%{input}"],
                outputs = ["%{output}"],
            ),
        ],
    )

2. 创建Feature绑定动作

定义一个Feature，指定动作依赖链接动作，确保在链接完成后执行：

def _generate_bin_hex_feature():
    return feature(
        name = "generate_bin_hex",
        actions = ["objcopy_bin", "objcopy_hex"],
        requires = ["link"],  # 依赖链接动作，保证执行顺序
    )

3. 整合到工具链配置

在工具链实现函数中，添加上述动作配置和Feature：

def _cc_toolchain_config_impl(ctx):
    # 原有工具路径定义（确保objcopy已正确配置）
    tool_paths = [
        tool_path(name = "gcc", path = ctx.attr.gcc_path),
        tool_path(name = "ld", path = ctx.attr.ld_path),
        tool_path(name = "objcopy", path = ctx.attr.objcopy_path),
        # 补充as、ar等其他必要工具路径
    ]

    # 原有动作配置 + 新增的objcopy动作
    action_configs = [
        # 保留你已有的编译、链接等动作配置
        # ...
        _objcopy_bin_action(),
        _objcopy_hex_action(),
    ]

    # 原有Feature + 新增的生成bin/hex的Feature
    features = [
        # 保留你已有的Feature
        # ...
        _generate_bin_hex_feature(),
    ]

    return cc_common.create_cc_toolchain_config_info(
        ctx = ctx,
        toolchain_identifier = "arm-gcc-toolchain",
        host_system_name = "local",
        target_system_name = ctx.attr.target_system_name,
        target_cpu = ctx.attr.target_cpu,
        target_libc = ctx.attr.target_libc,
        compiler = "gcc",
        abi_version = "none",
        abi_libc_version = "none",
        tool_paths = tool_paths,
        action_configs = action_configs,
        features = features,
    )

4. 启用Feature

有两种方式启用该Feature：

• 单个目标启用：在BUILD文件的cc_binary中指定features：

  cc_binary(
      name = "hello_world",
      srcs = ["hello_world.c"],
      features = ["generate_bin_hex"],
      toolchain = "@your_toolchain//:toolchain",  # 替换为你的工具链标签
  )
  

• 全局启用：在.bazelrc中添加全局配置：

  build --features=generate_bin_hex
  

验证与排查 #

• 确保objcopy的工具路径在tool_paths中正确配置，Bazel能找到该工具
• 检查Feature是否被正确关联，可通过bazel build --verbose_failures查看动作执行日志
• 若仍未触发，可尝试在Feature中添加enabled = True强制启用，或检查工具链是否被正确加载

内容的提问来源于stack exchange，提问作者CNC