实现offsetof的gcc插件

#include <gcc-plugin.h>
#include <tree.h>
#include <tree-pass.h>
#include <context.h>
#include <plugin-version.h>
#include <function.h>
#include <tree-pretty-print.h>
#include <tree-pass.h>
#include <tree-iterator.h>
#include <gimple.h>
#include <gimple-pretty-print.h>
#include <gimple-expr.h>
#include <gimple-iterator.h>
#include <gimple-ssa.h>
#include <gimple-ssa-strength-reduction.h>
#include <gimple-ssa-warn-undef.h>
#include <gimple-ssa-ccp.h>
#include <gimple-ssa-sprintf.h>
#include <gimple-ssa-sccvn.h>
#include <gimple-ssa-sccp.h>
#include <gimple-ssa-isolate-constants.h>
#include <gimple-ssa-sccp-verify.h>
#include <gimple-ssa-sccp-verify.h>
#include <gimple-ssa-sccp-verify.h>

int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
{
    // 插件初始化逻辑
    return 0;
}

int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
{
    // 注册GCC Pass
    register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &offsetof_pass_info);
    return 0;
}

static struct opt_pass offsetof_pass = {
    .type = GIMPLE_PASS,
    .name = "offsetof_pass",
    .gate = gate_true,
    .execute = execute_offsetof_pass,
    .sub = NULL,
    .next = NULL
};

static unsigned int execute_offsetof_pass(void)
{
    // 结构体成员偏移量计算逻辑
    return 0;
}

int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
{
    // 注册GCC Pass
    register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &offsetof_pass_info);
    // 添加GCC Pass到GCC Pass Manager
    struct register_pass_info pass_info;
    pass_info.pass = &offsetof_pass;
    pass_info.reference_pass_name = "ssa";
    pass_info.ref_pass_instance_number = 1;
    pass_info.pos_op = PASS_POS_INSERT_AFTER;
    register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &pass_info);
    return 0;
}

$ gcc -shared -o offsetof_plugin.so offsetof_plugin.c -fPIC -I /path/to/gcc/include -L /path/to/gcc/lib -l gcc

$ gcc -fplugin=./offsetof_plugin.so -o output source.c