Question

希望使用x86架构的nasm示例，该示例可以创建大小为“ n”的数组，其中“ n”是用户希望在运行时拥有数组大小的数字

extern _printf
extern _scanf
extern _scanf
global _main

section .data
    array:  10,5,4
    msg:    db  "enter the size of the array: ",10,0
    size:   db 10
    format: db "%i",0
section .text
    _main:
          push msg
          call _printf
          add esp, 4

          push size
          push format
          call _scanf
          add esp, 8

    ret

Answer 1

您的意思是否像BSS中的import React from 'react'; import { Route, Redirect } from 'react-router-dom'; import auth from '../_helpers/auth'; class PrivateRoute extends React.Component { getComponent = () => { const { component: Component, location } = this.props; if (auth.isAuthenticated) { return ( <Component {...this.props} /> ); } return ( <Redirect to={{ pathname: '/public', state: { from: location, }, }} /> ); } render() { const { ...rest } = this.props; return ( <Route {...rest} render={this.getComponent()} /> ); } }，用户可以使用resd n来构建程序以将NASM宏设置为常量？您可以使用nasm -felf -Dn=1024提供默认值。

如果您想要运行时可变的数组大小，则显然不能将其存储在静态存储中（除非您大量过度分配并且仅使用需要的数组任何部分。在为延迟分配空间的系统上很好） BSS。）

Answer 2

如果您满意Windows的示例，请参见EuroAssembler中的以下程序。它会创建3128字节长的 AllocArray.exe ，它将保留并初始化BSS部分中的请求大小。

AllocArray PROGRAM Format=PE, IconFile=, Entry=Main:
           INCLUDE winapi.htm, cpuext32.htm
%MaxPossibleLength %SETA 1_000_000 ; Specify the maximal acceptable allocation here.
[.text]
Main: StdOutput ="Enter the size of the array (1..%MaxPossibleLength): "
      StdInput EnterredLength    ; Let the user to set array length.
      LodD EnterredLength        ; Convert the enterred decimal number to integer in EAX.
      CMP EAX,%MaxPossibleLength
      JA Main:
      MOV [LengthOfTheArray],EAX
      StoD AllocatedLength       ; Convert the integer EAX to decimal.
      XOR EAX,EAX
      STOSB                      ; Zero-terminate the decimal number.
      MOV EDI,TheArray:
      MOV ECX,[LengthOfTheArray]
      MOV EAX,0x5A5A5A5A
      REP STOSD                  ; Initialize the array with 5A.
      StdOutput ="The array of ", AllocatedLength, =" DWORDs is now allocated statically."
      TerminateProgram
[.bss]
EnterredLength:   DB 16 * BYTE  
AllocatedLength:  DB 16 * BYTE  
LengthOfTheArray: DD DWORD
TheArray:         DD %MaxPossibleLength * DWORD
      ENDPROGRAM AllocArray

如何声明用户在nasm中指示的大小的数组？

2 个答案: