gistfile1.txt

#import <stdio.h>

int main(int argc, char **argv) {
  void(^doHello)() = ^{
    printf("Hello\n");
  };
  doHello();
  return 0;
}



__text:00001F10 ; Attributes: bp-based frame
__text:00001F10
__text:00001F10 ; int __cdecl main(int argc, char **argv)
__text:00001F10                 public _main
__text:00001F10 _main           proc near
__text:00001F10
__text:00001F10 var_zero        = dword ptr -18h
__text:00001F10 var_blockptr    = dword ptr -14h
__text:00001F10 var_argv        = dword ptr -10h
__text:00001F10 var_argc        = dword ptr -0Ch
__text:00001F10 var_unused      = dword ptr -8
__text:00001F10 argc            = dword ptr  8
__text:00001F10 argv            = dword ptr  0Ch
__text:00001F10
__text:00001F10                 push    ebp
__text:00001F11                 mov     ebp, esp
__text:00001F13                 push    esi
__text:00001F14                 sub     esp, 24h        ; set 0x24 byte stack
__text:00001F14                                         ; esp is extended (32-bit) stack pointer
__text:00001F17                 call    $+5
__text:00001F1C                 pop     eax
__text:00001F1D                 mov     ecx, [ebp+argv]
__text:00001F20                 mov     edx, [ebp+argc]
__text:00001F23                 mov     esi, 0
__text:00001F28                 lea     eax, [eax+104h] ; copy block pointer to register
__text:00001F2E                 mov     [ebp+var_unused], 0
__text:00001F35                 mov     [ebp+var_argc], edx ; args are moved to vars on stack
__text:00001F38                 mov     [ebp+var_argv], ecx
__text:00001F3B                 mov     [ebp+var_blockptr], eax
__text:00001F3E                 mov     eax, [ebp+var_blockptr] ; <-- that's awful redundant isn't it clang?
__text:00001F41                 mov     ecx, eax
__text:00001F43                 mov     [esp], ecx      ; put block pointer first on stack
__text:00001F46                 mov     [ebp+var_zero], esi ; esi is zero, from 1F23
__text:00001F46                                         ; weird that return code is setup before func is called?
__text:00001F49                 call    [eax+BlockStruct.invoke] ; blockFunc(var_blockptr)
__text:00001F4C                 mov     eax, [ebp+var_zero] ; set eax to zero (eax holds return code)
__text:00001F4F                 add     esp, 24h        ; empty stack
__text:00001F52                 pop     esi
__text:00001F53                 pop     ebp
__text:00001F54                 retn
__text:00001F54 _main           endp
__text:00001F54
__text:00001F54 ; ---------------------------------------------------------------------------
__text:00001F55                 align 10h
__text:00001F60
__text:00001F60 ; =============== S U B R O U T I N E =======================================
__text:00001F60
__text:00001F60 ; Attributes: bp-based frame
__text:00001F60
__text:00001F60 ; int __cdecl __main_block_invoke_0(void *blockptr)
__text:00001F60 ___main_block_invoke_0 proc near        ; DATA XREF: __const:___block_literal_globalo
__text:00001F60
__text:00001F60 var_printf_ret  = dword ptr -8
__text:00001F60 var_blockptr    = dword ptr -4
__text:00001F60 blockptr        = dword ptr  8
__text:00001F60
__text:00001F60                 push    ebp
__text:00001F61                 mov     ebp, esp
__text:00001F63                 sub     esp, 18h        ; sets up 0x18 byte stack
__text:00001F66                 call    $+5
__text:00001F6B                 pop     eax
__text:00001F6C                 mov     ecx, [ebp+blockptr]
__text:00001F6F                 lea     eax, (aHello - 1F6Bh)[eax] ; "Hello\n"
__text:00001F75                 mov     [esp], eax      ; moves "Hello\n"* to first stack position
__text:00001F78                 mov     [ebp+var_blockptr], ecx
__text:00001F7B                 call    _printf         ; printf("Hello\n")
__text:00001F80                 mov     [ebp+var_printf_ret], eax ; return value from printf is stored, unused
__text:00001F83                 add     esp, 18h
__text:00001F86                 pop     ebp
__text:00001F87                 retn
__text:00001F87 ___main_block_invoke_0 endp
__text:00001F87
__text:00001F87 __text          ends
__text:00001F87