在gcc内联汇编中调用一个函数 [英] Calling a function in gcc inline assembly

问题描述

说，我想在gcc的内联汇编中调用带有以下签名的函数。我该怎么做？

  int some_function（void * arg）; 
  

解决方案

p>

  void * x; 
 asm（..写入寄存器％0的代码：= r（x）：... 
 int r = some_function（x）; 
 asm（..使用结果的代码...：...：r（r），... 
  

也就是说，你不想在内联asm中执行函数调用，这样你就不必担心调用约定的细节或者堆栈框架管理。

Say, I want to call a function with the following signature in inline assembly of gcc. How can I do that?

int some_function( void * arg );

解决方案

Generally you'll want to do something like

void *x;
asm(".. code that writes to register %0" : "=r"(x) : ...
int r = some_function(x);
asm(".. code that uses the result..." : ... : "r"(r), ...

That is, you don't want to do the function call in the inline asm at all. That way you don't have to worry about details of the calling conventions, or stack frame management.

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