Reverse Engineering for Beginners

CHAPTER 51. C++ CHAPTER 51. C++

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X=garbage

Y=garbage

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X=1st element

Y=1st element

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X=2nd element

Y=2nd element

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X=3rd element

Y=3rd element

Variable std::list

list.end() list.begin()

GCC has its dummy element at the end of the list, while MSVC’s is at the beginning.

Listing 51.31: Optimizing MSVC 2012 /Fa2.asm /GS- /Ob1

_l$ = -16 ; size = 8
_t1$ = -8 ; size = 8
_main PROC
sub esp, 16
push ebx
push esi
push edi
push 0
push 0
lea ecx, DWORD PTR _l$[esp+36]
mov DWORD PTR _l$[esp+40], 0
; allocate first "garbage" element
call ?_Buynode0@?$_List_alloc@$0A@U?$_List_base_types@Ua@@V?⤦
Ç$allocator@Ua@@@std@@@std@@@std@@QAEPAU?$_List_node@Ua@@PAX@2@PAU32@0@Z ; std::⤦
Ç_List_alloc<0,std::_List_base_types<a,std::allocator > >::_Buynode0
mov edi, DWORD PTR impprintf
mov ebx, eax
push OFFSET $SG40685 ; '* empty list:'
mov DWORD PTR _l$[esp+32], ebx
call edi ; printf
lea eax, DWORD PTR _l$[esp+32]
push eax
call ?dump_List_val@@YAXPAI@Z ; dump_List_val
mov esi, DWORD PTR [ebx]
add esp, 8
lea eax, DWORD PTR _t1$[esp+28]
push eax
push DWORD PTR [esi+4]
lea ecx, DWORD PTR _l$[esp+36]
push esi
mov DWORD PTR _t1$[esp+40], 1 ; data for a new node
mov DWORD PTR _t1$[esp+44], 2 ; data for a new node
; allocate new node
call ??$_Buynode@ABUa@@@?$_List_buy@Ua@@V?$allocator@Ua@@@std@@@std@@QAEPAU?⤦
Ç$_List_node@Ua@@PAX@1@PAU21@0ABUa@@@Z ; std::_List_buy<a,std::allocator >::_Buynode<a ⤦
Çconst &>
mov DWORD PTR [esi+4], eax
mov ecx, DWORD PTR [eax+4]
mov DWORD PTR _t1$[esp+28], 3 ; data for a new node
mov DWORD PTR [ecx], eax
mov esi, DWORD PTR [ebx]
lea eax, DWORD PTR _t1$[esp+28]
push eax
push DWORD PTR [esi+4]
lea ecx, DWORD PTR _l$[esp+36]
push esi
mov DWORD PTR _t1$[esp+44], 4 ; data for a new node