教程：适用于 Bazel，基于 FIDL 的绑定库

本教程适用于使用 SDK 且希望使用基于 FIDL 的自动生成的绑定库的驱动程序作者。本教程假定您熟悉以下内容：

• FIDL 教程 - 生成的绑定库
• 为驱动程序创建新的绑定库

相同点和不同点是什么？

上述链接教程中介绍的大多数概念和示例也适用于 SDK 用户。

仅有的几点区别如下：

• 如果基于 FIDL 的绑定库 fuchsia_fidl_bind_library 的 Bazel 目标并非来自 SDK，则需要手动添加 FIDL 库。
• 如果 FIDL 库不是来自 SDK，则需要手动添加绑定库代码生成目标 fuchsia_bind_cc_library 的 Bazel 目标。

示例

本部分中的示例展示了一个手动定义的 FIDL 库，以及如何使用生成的绑定库及其关联的生成代码为子驱动程序创建绑定规则，并从父驱动程序访问这些绑定库值的常量。

BUILD.bazel

FIDL 库

# This is a FIDL library that we manually define.
fuchsia_fidl_library(
    name = "examples.gizmo",
    srcs = [
        "testfidl.fidl",
    ],
    library = "examples.gizmo",
)

# The C++ bindings for the FIDL library.
fuchsia_fidl_llcpp_library(
    name = "examples.gizmo_cc",
    library = ":examples.gizmo",
    visibility = ["//visibility:public"],
    deps = [
        "@fuchsia_sdk//pkg/fidl_cpp_v2",
        "@fuchsia_sdk//pkg/fidl_cpp_wire",
    ],
)

# We have to manually create the bind library from it.
fuchsia_fidl_bind_library(
    name = "examples.gizmo_bindlib",
    library = ":examples.gizmo",
    visibility = ["//visibility:public"],
)

# We have to manually create the C++ lib for the FIDL based bind library we created.
fuchsia_bind_cc_library(
    name = "examples.gizmo_bindlib_cc",
    library = ":examples.gizmo_bindlib",
    visibility = ["//visibility:public"],
)

家长司机

fuchsia_cc_driver(
    name = "parent_driver",
    srcs = [
        "gizmo_server.h",
        "parent-driver.cc",
        "parent-driver.h",
    ],
    deps = [
        # This is a C++ lib from our manually created bind library.
        "//src/bind_library/lib:examples.gizmo.bind_cc",
        # This is a C++ lib from our manually created FIDL based bind library.
        "//src/bind_library/lib:examples.gizmo_bindlib_cc",
        "//src/bind_library/lib:examples.gizmo_cc",
        # This is a C++ lib from an SDK FIDL based bind library.
        "@fuchsia_sdk//fidl/fuchsia.device.fs:fuchsia.device.fs_bindlib_cc",
        "@fuchsia_sdk//pkg/driver_component_cpp",
    ],
)

子绑定规则

fuchsia_driver_bind_bytecode(
    name = "bind_bytecode",
    output = "child-driver.bindbc",
    rules = "child-driver.bind",
    deps = [
        # This bind library is one we created manually.
        "//src/bind_library/lib:examples.gizmo.bind",
        # This bind library is from a FIDL library that we created manually.
        "//src/bind_library/lib:examples.gizmo_bindlib",
        # This bind library is from an SDK FIDL library.
        "@fuchsia_sdk//fidl/fuchsia.device.fs:fuchsia.device.fs_bindlib",
    ],
)

parent-driver.cc

#include <bind/examples/gizmo/bind/cpp/bind.h>
#include <bind/examples/gizmo/cpp/bind.h>
#include <bind/fuchsia/device/fs/cpp/bind.h>

...

properties[4] = fdf::MakeProperty(arena, bind_fuchsia_device_fs::EXPORTER,
                                  bind_fuchsia_device_fs::EXPORTER_ZIRCONTRANSPORT);
properties[5] = fdf::MakeProperty(arena, bind_examples_gizmo::TESTINGPROTOCOL,
                                  bind_examples_gizmo::TESTINGPROTOCOL_ZIRCONTRANSPORT);

子级驱动程序.bind

using fuchsia.device.fs;
using examples.gizmo;

...

fuchsia.device.fs.Exporter == fuchsia.device.fs.Exporter.ZirconTransport;
examples.gizmo.TestingProtocol == examples.gizmo.TestingProtocol.ZirconTransport;