CHAPTER 51. C++ CHAPTER 51. C++
Listing 51.27: MSVC 2012: this destructor function is called before exit??Fs@@YAXXZ PROC
push ecx
cmp DWORD PTR ?s@@3V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A+20, 16
jb SHORT $LN23@dynamic
push esi
mov esi, DWORD PTR ?s@@3V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A
lea ecx, DWORD PTR $T2[esp+8]
call ??0?$_Wrap_alloc@V?$allocator@D@std@@@std@@QAE@XZ
push OFFSET ?s@@3V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A ; s
lea ecx, DWORD PTR $T2[esp+12]
call ??$destroy@PAD@?$_Wrap_alloc@V?$allocator@D@std@@@std@@QAEXPAPAD@Z
lea ecx, DWORD PTR $T1[esp+8]
call ??0?$_Wrap_alloc@V?$allocator@D@std@@@std@@QAE@XZ
push esi
call ??3@YAXPAX@Z ; operator delete
add esp, 4
pop esi
$LN23@dynamic:
mov DWORD PTR ?s@@3V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A+20, 15
mov DWORD PTR ?s@@3V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A+16, 0
mov BYTE PTR ?s@@3V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A, 0
pop ecx
ret 0
??Fs@@YAXXZ ENDP
In fact, a special function with all constructors of global variables is called fromCRT, before main(). More than that: with
the help of atexit() another function is registered, which contain calls to all destructors of such global variables.
GCC works likewise:
Listing 51.28: GCC 4.8.1main:
push ebp
mov ebp, esp
and esp, -16
sub esp, 16
mov eax, DWORD PTR s
mov DWORD PTR [esp], eax
call puts
xor eax, eax
leave
ret
.LC0:
.string "a string"
_GLOBALsub_I_s:
sub esp, 44
lea eax, [esp+31]
mov DWORD PTR [esp+8], eax
mov DWORD PTR [esp+4], OFFSET FLAT:.LC0
mov DWORD PTR [esp], OFFSET FLAT:s
call _ZNSsC1EPKcRKSaIcE
mov DWORD PTR [esp+8], OFFSET FLAT:dso_handle
mov DWORD PTR [esp+4], OFFSET FLAT:s
mov DWORD PTR [esp], OFFSET FLAT:_ZNSsD1Ev
call cxa_atexit
add esp, 44
ret
.LFE645:
.size _GLOBAL__sub_I_s, .-_GLOBALsub_I_s
.section .init_array,"aw"
.align 4
.long _GLOBAL__sub_I_s
.globl s
.bss
.align 4
.type s, @object
.size s, 4
s:
.zero 4