The constructor of CPP disassembly analysis

The subclass constructor calls the parent class first. The subclass retains a piece of space for the parent class.

An example is given to analyze:

Class A  {public  :      A ()  {     }      ~a () {    cout<< "~a" <<endl;   }  };     Class B:public A  {public      :          B (a &a): _a (a)          {                       }          ~b ()          {              cout<< "~b" <<endl;          }      Private:          A _a;      };         int main (void)   {          a A;       It is simple to define a when a constructor          b b (a) is called;

Here's the disassembly code.

1: #include <iostream>2:using namespace Std;3:class A4: {5:public:6: A () 00401240 push EBP00401241 mov ebp,esp00401243 Sub esp,44h00401246 push ebx00401247 push esi004 01248 push edi00401249 push ecx0040124a Lea EDI,[EBP-44H]0040124D mov ecx,11h0040125  2 mov eax,0cccccccch00401257 rep stos dword ptr [edi]00401259 pop ecx0040125a mov DWORD PTR [ebp-4],ecx7: {8:cout << ' A construct ' << endl;0040125d push offset @ILT +35 (s Td::endl) (00401028) 00401262 push offset string "A construct" (0043201c) 00401267 push offset std::cout (         00439528) 0040126C call @ILT +180 (std::operator<<) (004010b9) 00401271 add esp,800401274 mov ecx,eax00401276 call @ILT +120 (std::basic_ostream<char,std::char_traits<char> >::operator<<) (0040107d) 9:}0040127B mov eax,dword ptr [ebp-4]0040127e pop edi0040127f pop esi00401280 pop ebx004         01281 Add esp,44h00401284 cmp ebp,esp00401286 call __CHKESP (004096E0) 0040128B mov  esp,ebp0040128d pop ebp0040128e ret10:a operator= (const A &a) One by one: {12:cout << "operator =" << Endl;13:return a;14:}15:a (const a& a) copy constructor 004013b0 push EBP   004013B1 mov ebp,esp004013b3 Sub esp,44h004013b6 push ebx004013b7 push ESI004013B8          Push EDI004013B9 push ecx004013ba Lea EDI,[EBP-44H]004013BD mov ecx,11h004013c2 mov Eax,0cccccccch004013c7 Rep stos dword ptr [edi]004013c9 pop ECX004013CA mov dword ptr [E bp-4],ecx16: {17:cout << "const a&" << ENDL;004013CD push offset @ILT +35 (std::en  DL) (00401028) 004013d2 Push offset string "Const a&" (00432030) 004013d7 push offset std::cout (00439528) 004013DC call        @ILT +180 (std::operator<<) (004010b9) 004013E1 add ESP,8004013E4 mov ecx,eax004013e6 call    @ILT +120 (std::basic_ostream<char,std::char_traits<char> >::operator<<) (0040107d):}004013eb    mov Eax,dword ptr [ebp-4]004013ee pop edi004013ef pop esi004013f0 pop ebx004013f1 Add ESP,44H004013F4 cmp Ebp,esp004013f6 call __CHKESP (004096e0) 004013FB mov esp,e         BP004013FD Pop ebp004013fe ret 419: ~a (): {004012b0 push EBP004012B1 mov Ebp,esp004012b3 Sub Esp,44h004012b6 push ebx004012b7 push esi004012b8 push edi004 012B9 push ecx004012ba Lea EDI,[EBP-44H]004012BD mov ECX,11H004012C2 mov eax,0ccccc Ccch004012c7 Rep STOs   DWORD ptr [EDI]004012C9 pop ECX004012CA mov dword ptr [ebp-4],ecx21:cout<< "~a" < &LT;ENDL;004012CD Push offset @ILT +35 (Std::endl) (00401028) 004012D2 push offset string "~a" (0043202c) 00   4012d7 Push offset std::cout (00439528) 004012DC call @ILT +180 (std::operator<<) (004010B9) 004012E1 Add ESP,8004012E4 mov ecx,eax004012e6 call @ILT +120 (Std::basic_ostream<char,std::char_trai   Ts<char> >::operator<<) (0040107d):}004012eb pop edi004012ec pop esi004012ed Pop ebx004012ee Add esp,44h004012f1 cmp ebp,esp004012f3 call __CHKESP (004096E0) 0040 12F8 mov esp,ebp004012fa pop ebp004012fb ret23:};24:25:class b:public A26: {27:public        : 28:b (a &a): _a (a): {00401310 push ebp00401311 mov ebp,esp00401313 push 0ffh00401315 push       Offset [Email protected]@[email protected]@@@z (0041fd79) 0040131A mov eax,fs:[00000000]00401320 Push eax00401321 mov dword ptr fs:[0],esp00401328 Sub esp,44h0040132b push ebx00401 32C push esi0040132d push edi0040132e push ecx0040132f Lea edi,[ebp-50h]00401332 mo V ecx,11h00401337 mov eax,0cccccccch0040133c rep stos dword ptr [edi]0040133e pop ecx0040 133F mov dword ptr [ebp-10h],ecx00401342 mov ecx,dword ptr [ebp-10h]00401345 call @ILT +80 (A:: A) (00401055) General Constructor Class B has a Class A object.   0040134A mov dword ptr [ebp-4],000401351 mov eax,dword ptr [ebp+8]00401354 push eax00401355           mov Ecx,dword ptr [ebp-10h]00401358 call @ILT +165 (a::a) (004010AA) copy constructor://_a = a;31:   }0040135D mov dword ptr [ebp-4],0ffffffffh00401364 mov eax,dword ptr [ebp-10h]00401367mov ecx,dword ptr [ebp-0ch]0040136a mov dword ptr fs:[0],ecx00401371 pop edi00401372 pop esi00401373 pop ebx00401374 Add esp,50h00401377 cmp ebp,esp00401379 call __chk           ESP (004096E0) 0040137E mov esp,ebp00401380 pop ebp00401381 ret 432: ~b () 33: {00401420 push ebp00401421 mov ebp,esp00401423 push 0ffh00401425 push offset [EMA Il protected]@[email protected] (0041fda2) 0040142A mov eax,fs:[00000000]00401430 push eax0040 1431 mov DWORD ptr fs:[0],esp00401438 Sub esp,44h0040143b push ebx0040143c push Esi0 040143D push edi0040143e push ecx0040143f Lea edi,[ebp-50h]00401442 mov ecx,11h00401 447 mov eax,0cccccccch0040144c rep stos dword ptr [edi]0040144e pop ecx0040144f mov dwo Rd PTR [ebp-10h],ecx00401452 mov dword ptr [ebp-4],134:cout<< "~b" <<endl;00401459 push offset @ILT +35 (Std::endl)   (00401028) 0040145E push offset string "~b" (0043203c) 00401463 push offset std::cout (00439528) 00401468   Call @ILT +180 (std::operator<<) (004010b9) 0040146D add esp,800401470 mov ecx,eax00401472           Call @ILT +120 (std::basic_ostream<char,std::char_traits<char> >::operator<<) (0040107d) 35: }00401477 mov byte ptr [ebp-4],00040147b mov ecx,dword ptr [ebp-10h]0040147e call @ILT +1 Ten (A::~a) (00401073) 00401483 mov dword ptr [ebp-4],0ffffffffh0040148a mov ecx,dword ptr [ebp-10h]00401  48D call @ILT +110 (a::~a) (00401073) 00401492 mov ecx,dword ptr [ebp-0ch]00401495 mov dword ptr fs:[0],ecx0040149c pop edi0040149d pop esi0040149e pop ebx0040149f add esp,50h004 014A2 CMP        EBP,ESP004014A4 call __chkesp (004096e0) 004014a9 mov esp,ebp004014ab pop ebp004014ac   RET36:PRIVATE:37:A _a;38:};39:40:int main (void): {00401190 push ebp00401191         MOV ebp,esp00401193 push 0ffh00401195 push offset __ehhandler$_main (0041fd59) 0040119A mov EAX,FS:[00000000]004011A0 push EAX004011A1 mov dword ptr fs:[0],esp004011a8 Sub Esp,4ch0   04011AB push ebx004011ac push esi004011ad push edi004011ae Lea EDI,[EBP-58H]004011B1       MOV ECX,13H004011B6 mov EAX,0CCCCCCCCH004011BB rep stos dword ptr [Edi]42:a A;         It is simple to define a when a constructor is called 004011BD Lea ecx,[ebp-10h]004011c0 call @ILT +80 (a::a) (00401055) 004011C5 mov         DWORD ptr [Ebp-4],043:b B (a); 004011CC Lea EAX,[EBP-10H]004011CF push eax004011d0 Lea ecx,[ebp-14h]004011d3 call @ILT +155 (b::b) (004010a0) 44:return 0;004011d8 mov dword ptr [EBP-18H],0004011DF Lea Ecx,[ebp-14h]004011e2 call @ILT +130 (b::~b) (00401087) 004011E7 mov dword ptr [EBP-4],0FFFFFF Ffh004011ee Lea ECX,[EBP-10H]004011F1 call @ILT +110 (a::~a) (00401073) 004011F6 mov eax,dword p          TR [ebp-18h]45:}004011F9 mov ecx,dword ptr [EBP-0CH]004011FC mov dword ptr fs:[0],ecx00401203 pop edi00401204 pop esi00401205 pop ebx00401206 add esp,58h00401209 cmp ebp,e sp0040120b call __chkesp (004096e0) 00401210 mov esp,ebp00401212 pop ebp00401213 ret@ilt+145         (_main): 00401096 jmp Main (00401190) @ILT +155 ([email protected]@[email protected]@@@z): 004010a0 jmp B::b (00401310) @ILT +165 ([email protected]@[email protected]@@z): 004010AA jmp a::a (004013b0) replication function @ilt+110 ([email Protected]@[email protected]): 00401073 jmp a::~a (004012b0) @ILT +130 ([Email protected]@[email prot         Ected]: 00401087 jmp b::~b (00401420) @ILT +80 ([email protected]@[email protected]): 00401055 jmp A::a (00401240) General constructors

The constructor of CPP disassembly analysis