gcc-plugin

1. Get Start

dnf install gcc-plugin-devel

cpp

// plugin.cc
#include <gcc-plugin.h>
#include <plugin-version.h>

int plugin_is_GPL_compatible;

int plugin_init(plugin_name_args *plugin_info, plugin_gcc_version *version) {
    if (!plugin_default_version_check(version, &gcc_version)) {
        printf("incompatible gcc/plugin versions\n");
        return 1;
    }
    printf("Hello world!\n");
    return 0;
}

1.1. 直接编译

编译插件

g++ plugin.cc -c -o plugin.o -I`g++ -print-file-name=plugin`/include -std=c++17 -Wall -fPIC
g++ plugin.o -fPIC -shared -o libplugin.so

使用插件

g++ test.cc -o test -fplugin=libplugin.so

编译 test.cc 时会出现 Hello world!

1.2. cmake 构建

编译插件（plugin 目录）

cmake

cmake_minimum_required(VERSION 3.10)
project(plugin VERSION 1.0)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

add_library(${PROJECT_NAME} SHARED plugin.cc)

execute_process(COMMAND g++ "-print-file-name=plugin" OUTPUT_VARIABLE gcc_plugin_dir)
string(STRIP ${gcc_plugin_dir} gcc_plugin_dir)

target_compile_features(${PROJECT_NAME} PRIVATE cxx_std_20)
target_compile_options(${PROJECT_NAME} PRIVATE -Wall -I${gcc_plugin_dir}/include)

编译并使用插件

mkdir -p build
cmake -B build . && cmake --build build -- "$@"
g++ test.cc -o build/test -fplugin=build/plugin/libplugin.so

1.3. clang-format 修改

context.h 头文件不是自包含的，加上 SortIncludes: false 禁止头文件排序

2. 基本结构

cpp

int plugin_is_GPL_compatible; // 不用管
int plugin_init(plugin_name_args *plugin_info, plugin_gcc_version *version); // 插件加载时执行

回调函数，在 plugin_init 里注册，注册函数 register_callback 的签名：

cpp

void register_callback(const char *plugin_name, int event, plugin_callback_func callback, void *user_data);

3. 事件

3.1. 包含头文件

PLUGIN_INCLUDE_FILE

所有 #include 会触发

cpp

#include <gcc-plugin.h>
#include <plugin-version.h>

int plugin_is_GPL_compatible;

void file_included(void *gcc_data, void *user_data) {
    printf("file included: %s\n", (char *)gcc_data);
}

int plugin_init(plugin_name_args *plugin_info, plugin_gcc_version *version) {
    if (!plugin_default_version_check(version, &gcc_version)) {
        printf("incompatible gcc/plugin versions\n");
        return 1;
    }
    const char *plugin_name = plugin_info->base_name;
    register_callback(plugin_name, PLUGIN_INCLUDE_FILE, file_included, NULL);
    return 0;
}

3.2. 声明

PLUGIN_FINISH_DECL

函数声明 function_decl
变量声明和定义 var_decl

cpp

#include <gcc-plugin.h>
#include <plugin-version.h>
#include <tree-pass.h>
#include <context.h>
#include <tree.h>

int plugin_is_GPL_compatible;

void finish_decl(void *event, void *__unused__) {
    tree decl = (tree)event;
    const char *file = DECL_SOURCE_FILE(decl);
    int line = DECL_SOURCE_LINE(decl);
    int column = DECL_SOURCE_COLUMN(decl);
    const char *name = DECL_NAME(decl) != NULL_TREE
                           ? IDENTIFIER_POINTER(DECL_NAME(decl))
                           : "<unamed>";
    const char *type = get_tree_code_name(TREE_CODE(decl));
    printf("%s:%d:%d: %s (%s)\n", file, line, column, name, type);
}

int plugin_init(plugin_name_args *plugin_info, plugin_gcc_version *version) {
    if (!plugin_default_version_check(version, &gcc_version)) {
        printf("incompatible gcc/plugin versions\n");
        return 1;
    }
    const char *const plugin_name = plugin_info->base_name;
    register_callback(plugin_name, PLUGIN_FINISH_DECL, finish_decl, NULL);
    return 0;
}

gcc-plugin ​

1. Get Start ​

1.1. 直接编译 ​

1.2. cmake 构建 ​

1.3. clang-format 修改 ​

2. 基本结构 ​

3. 事件 ​

3.1. 包含头文件 ​

3.2. 声明 ​