-ARM64    http://infocenter.arm.com/help/topic/com.arm.doc.den0024a/DEN0024A_v8_architecture_PG.pdf (7.2.1 Floating-point) (4.6.1 Floating-point register organization in AArch64)    use struct and union to describe diagram in the above link, nice!    -X86    https://en.wikipedia.org/wiki/X86_calling_conventions    RDI, RSI, RDX, RCX, R8, R9, XMM0–7*/// x86_64 is XMM, arm64 is qtypedef union FPMReg_ {    __int128_t q;    struct {        double d1; // Holds the double (LSB).        double d2;    } d;    struct {        float f1; // Holds the float (LSB).        float f2;        float f3;        float f4;    } f;} FPReg;// just ref how to backup/restore registersstruct RegState_ {    uint64_t bp;    uint64_t ret;    union {        uint64_t arr[7];        struct {            uint64_t rax;            uint64_t rdi;            uint64_t rsi;            uint64_t rdx;            uint64_t rcx;            uint64_t r8;            uint64_t r9;        } regs;    } general;    uint64_t _; // for align        union {        FPReg arr[8];        struct {            FPReg xmm0;            FPReg xmm1;            FPReg xmm2;            FPReg xmm3;            FPReg xmm4;            FPReg xmm5;            FPReg xmm6;            FPReg xmm7;        } regs;    } floating;};typedef struct pa_list_ {    struct RegState_ *regs; // Registers saved when function is called.    unsigned char *stack; // Address of current argument.    int ngrn; // The Next General-purpose Register Number.    int nsrn; // The Next SIMD and Floating-point Register Number.} pa_list;

    arg1: object-address(need to parse >> class)    arg2: method string address    arg3: method signature*/vm_address_t hookBefore(struct RegState_ *rs){    gettimeofday(&start,NULL);    // TODO: parse args    pa_list args = (pa_list){        rs,        reinterpret_cast<unsigned char *>(rs->bp),        2,        0};    ThreadCallStack *cs = getThreadCallStack(threadKey);    ReturnPayload *rp = cs->rp;    vm_address_t xaddr = (uint64_t)orig_objc_msgSend;    rp->addr = xaddr;    rp->ret = rs->ret;    rp->bp = rs->bp;    rp->isTrace = 0;    rp->key = rs->ret & rs->bp;    if (1 || pthread_main_np())    {        /*             pay attention!!! as `objc_msgSend` invoked so often, the `filter` code snippet that use `c` to write it must be fast!!!.        */        do        {               // check method string address, can be narrow the scope.            char *methodSelector = reinterpret_cast<char *>(rs->general.regs.rsi);            if(!(methodSelector && checkAddressRange((vm_address_t)methodSelector, macho_load_addr, macho_load_end_addr)))                break;            // check object's class address            vm_address_t class_addr = macho_objc_getClass(rs->general.regs.rdi);            if (!(class_addr && checkAddressRange(class_addr, macho_load_addr, macho_load_end_addr)))                break;            // check `call count filter`            if(check_freq_filter((unsigned long)methodSelector))                break;                        // // test for wechat            // if(!strncmp(methodSelector, "onRevokeMsg", 9))            //     debug_break();            // check exclude            // check method_name first, no need parse object.            if (!checkLogFilters_MethodName(NULL, methodSelector, FT_EXINLUDE))                break;            objc_class_info_t *xobjc_class_info;            xobjc_class_info = mem->parse_OBJECT(rs->general.regs.rdi);            if(!xobjc_class_info)                break;                        // check class name, need parse object            if (!checkLogFilters_ClassName(xobjc_class_info->class_name, NULL, FT_EXINLUDE))                break;            objc_method_info_t * objc_method_info;            objc_method_info = search_method_name(&(xobjc_class_info->methods), methodSelector);            if (!objc_method_info)                break;            if(check_thread_filter(cs->thread))                break;            // add to `method call count cache`            add_freq_filter((unsigned long)methodSelector, objc_method_info);            // may be can pass into 'objc_method_info_t' without 'class_name' and 'method_name'            CallRecord *cr = pushCallRecord(xobjc_class_info->class_name, methodSelector, reinterpret_cast<void *>(rs->bp), reinterpret_cast<void *>(rs->ret), cs);            if(!cr)                break;            printCallRcord(cr, cs);            rp->isTrace = 1;        } while(0);    }    gettimeofday(&end,NULL);    time_cost += (end.tv_sec-start.tv_sec)+(end.tv_usec-start.tv_usec)/1000000.0;    return reinterpret_cast<unsigned long>(rp);}

vm_address_t hookAfter(struct RegState_ *rs){    pa_list args = (pa_list){        rs,        reinterpret_cast<unsigned char *>(rs->bp),        2,        0};    ThreadCallStack *cs = getThreadCallStack(threadKey);    CallRecord *cr = popCallRecordSafe(cs, (void *)rs->bp);    if (cr)    {        // printCallRcordReturnValue(cr, cs, rs);        return reinterpret_cast<unsigned long>(cr->ret);    }    else    {        cr = popCallRecord(cs);        return reinterpret_cast<unsigned long>(cr->ret);    }}