Assembly Language for Beginners

3.18. C++

Listing 3.89: Optimizing MSVC 2008 /Ob0

?dump@box@@QAEXXZ PROC ; box::dump, COMDAT
; _this$ = ecx
mov eax, DWORD PTR [ecx+12]
mov edx, DWORD PTR [ecx+8]
push eax
mov eax, DWORD PTR [ecx+4]
mov ecx, DWORD PTR [ecx]
push edx
push eax
push ecx

; 'this is box. color=%d, width=%d, height=%d, depth=%d', 0aH, 00H ; `string'
push OFFSET ??_C@_0DG@NCNGAADL@this?5is?5box?4?5color?$DN?$CFd?0?5width?$DN?$CFd?0@
call _printf
add esp, 20
ret 0
?dump@box@@QAEXXZ ENDP ; box::dump

Listing 3.90: Optimizing MSVC 2008 /Ob0

?dump@sphere@@QAEXXZ PROC ; sphere::dump, COMDAT
; _this$ = ecx
mov eax, DWORD PTR [ecx+4]
mov ecx, DWORD PTR [ecx]
push eax
push ecx

; 'this is sphere. color=%d, radius=%d', 0aH, 00H
push OFFSET ??_C@_0CF@EFEDJLDC@this?5is?5sphere?4?5color?$DN?$CFd?0?5radius@
call _printf
add esp, 12
ret 0
?dump@sphere@@QAEXXZ ENDP ; sphere::dump

So, here is the memory layout:

(base classobject)

offset description

+0x0 int color

(inherited classes)

box:

offset description

+0x0 int color

+0x4 int width

+0x8 int height

+0xC int depth

sphere:

offset description

+0x0 int color

+0x4 int radius

Let’s seemain()function body:

Listing 3.91: Optimizing MSVC 2008 /Ob0

PUBLIC _main
_TEXT SEGMENT
_s$ = -24 ; size = 8
_b$ = -16 ; size = 16
_main PROC
sub esp, 24
push 30
push 20
push 10
push 1