function calling convention

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Parameter Pass Order

1. Right-to-left in the stack: __stdcall,__cdecl,__thiscall,__fastcall

2. From left to right into the stack: __pascal

Main description __stdcall and __cdecl difference

1...__stdcall The called function itself is responsible for stack balancing

2...__CDECL Call function is responsible for the stack balance of the function

The __stdcall function itself is responsible for stack balancing *********************////////////////

Int  __stdcall a (int v1,int xx) {return 5;} Int main () {int t=a (5,1); return 0;} /**/--- c:\users\hekun\desktop\cppp\cppp\ source .cpp -------------------------------------int  _ _stdcall a (INT V1,INT XX) {001713c0  push         ebp  001713c1  mov         ebp,esp   001713C3  sub         esp,0C0h   001713c9  push        ebx  001713ca   push        esi  001713cb  push         edi  001713CC  lea          edi,[ebp-0C0h]  001713D2  mov          ecx,30h  001713D7  mov         eax,0CCCCCCCCh   001713dc  rep stos    dword ptr es:[edi]  return  5;001713de  mov         eax,5  } 001713e3  pop         edi  001713e4   pop         esi  001713E5  pop          ebx  001713E6  mov          esp,ebp  001713E8  pop          ebp  001713E9  ret          8  /* stack balance   function parameters occupy 8 bytes */--- c:\users\hekun\desktop\cppp\cppp\ source .cpp --------------------- ----------------Int maiN () {00171400  push        ebp  00171401   mov         ebp,esp  00171403  sub          esp,0CCh  00171409  push         ebx  0017140A  push         esi  0017140b  push        edi   0017140C  lea         edi,[ebp-0CCh]   00171412  mov         ecx,33h  00171417   mov         eax,0CCCCCCCCh  0017141C   rep stos    dword ptr es:[edi]  int t=a (5,1); 0017141E   push        1  00171420  push         5  00171422  call        a  ( 01711E0H)   /*  Call function a*/00171427  mov          dword ptr [t],eax  /* return value is located in register eax*/return 0;0017142a  xor          eax,eax  }0017142C  pop          edi  0017142D  pop          esi  0017142e  pop         ebx   0017142F  add         esp,0CCh   00171435  cmp         ebp,esp  00171437   call        __rtc_checkesp  (017113Bh)   0017143C  mov          esp,ebp  0017143E  pop          ebp  0017143f  ret

? __cdecl ? The calling function is responsible for stack balancing *********************////////////////

Int  __cdecl a (int v1,int xx) {return 5;} Int main () {int t=a (5,1); return 0;} /* Disassembly */--- c:\users\hekun\desktop\cppp\cppp\ source .cpp -------------------------------------int   __cdecl a (INT V1,INT XX) {00f313c0  push         EBP  00F313C1  MOV         EBP, esp  00f313c3  sub         esp,0c0h   00F313C9  push        ebx  00F313CA   push        esi  00F313CB  push         edi  00F313CC  lea          edi,[ebp-0C0h]  00F313D2  mov          ecx,30h  00f313d7  mov         eax,0cccccccch   00f313dc  rep stos    dword ptr es:[edi]  return  5;00f313de  mov         eax,5  } 00f313e3  pop         edi  00f313e4   pop         esi  00F313E5  pop          ebx  00F313E6  mov          esp,ebp  00F313E8  pop          ebp  00F313E9  ret  --- c:\users\hekun\desktop\cppp\cppp\ SOURCE .cpp -------------------------------------Int main () {00f31400  push         ebp  00F31401  mov         ebp,esp   00f31403  sub         esp,0cch  00f31409   push        ebx  00F3140A  push         esi  00F3140B  push         edi  00F3140C  lea          edi,[ebp-0CCh]  00F31412  mov          Ecx,33h  00f31417  mov         eax,0cccccccch   00F3141C  rep stos    dword ptr es:[edi]   Int t=a (5,1);00f3141e  push        1   00f31420  push        5  00f31422  call         a  (0f311e5h)   /*  call function  a  */00F31427  add          esp,8     /*  because it is  __cdecl   Call way   So the caller  main  responsible for stack balancing, function a  back   immediately stack balance (8 bytes)    argument function can only be such a call, because only the caller knows   Parameter Actual size */00f3142a  mov         dword ptr  [t],eax  return 0;00F3142D  xor          eax,eax  }00f3142f  pop         edi   00F31430  pop         esi   00f31431  pop         ebx  00f31432   add         esp,0cch  00f31438  cmp          ebp,esp  00f3143a  call        _ _rtc_checkesp  (0F3113BH)   00F3143F  mov          esp,ebp  00F31441  pop          Ebp  00f31442  ret

__fastcall call parameters up to 8 bytes at a time put register ECX and edx rest parameters into the stack

function calling convention