如何在Linux 32位计算机上解决REG_EIP未声明(在此函数中首次使用)错误？

void print_registers(FILE *fd,ucontext_t *ctx,bool fpu = falsE)
{
        const char *flags_str[] = {
                "CF","PF","AF","ZF","SF","TP","IF","DF","OF","NT","RF","VM","AC","VIF","VIP","ID"
        };

        greg_t *regs = ctx->uc_mcontext.gregs;

        void *eip[1] = { (void*)regs[REG_EIP] };

        char **symbol = BACktrace_symbols(eip,1);

        fprintf(fd,"Registers:\neip is at ");

         BACktrace_symbols_fd(eip,1,fd->_fileno);

        size_type flags = regs[REG_EFL];
        fprintf(fd,"eflags: %x [ ",flags);
        for (size_type i = 0; i < sizeof(flags_str) / sizeof(flags_str[0]); ++i) {
                if (!flags_str[i]) conTinue;
                if (flags & (1 << i)) fprintf(fd,"%s ",flags_str[i]);
        }
        size_type iopl = (flags & 0x3000) >> 12;

            fprintf(fd,"] iopl: %i\n"
                                        "eax: %08x\tebx: %08x\tecx: %08x\tedx: %08x\n"
                                        "esi: %08x\tedi: %08x\tebp: %08x\tesp: %08x\n"
                                        "cs: %04x\tgs: %04x\tfs: %04x\n"
                                        "ds: %04x\tes: %04x\tss: %04x\n",iopl,regs[REG_EAX],regs[REG_EBX],regs[REG_ECX],regs[REG_EDX],regs[REG_ESI],regs[REG_EDI],regs[REG_EBP],regs[REG_ESP],regs[REG_CS],regs[REG_GS],regs[REG_FS],regs[REG_DS],regs[REG_ES],regs[REG_SS]);
                    }
                }

我通过添加尝试了代码

#include<sys/ucontext.h>

以及

#define _GNU_sourcE
                 #ifndef REG_EIP
                 #define REG_EIP 0x23b46F
                 #endif

但是,出现的错误是：

‘REG_EIP’ undeclared (first use in this function) 
 (Each undeclared identifier is reported only once  for each function it appears in.)

并且所有寄存器都出现错误

我尝试了很多文件……但无法得到解决方案.
任何人都可以共享解决此错误的详细信息.

感谢所有的回复者