字符串文字汇编 [英] Compilation of string literals

问题描述

为什么要用空格，制表符或 \n分隔的两个字符串文字正确无误地编译？

Why can two string literals separated by a space, tab or "\n" be compiled without an error?

int main()
{
   char * a = "aaaa"  "bbbb";
} 

aaaa是一个字符*
bbbb是一个char *

"aaaa" is a char* "bbbb" is a char*

没有特定的串联规则来处理两个字符串文字。很显然，以下代码在编译期间会出现错误：

There is no specific concatenation rule to process two string literals. And obviously the following code gives an error during compilation:

#include <iostream>
int main()
{
   char * a = "aaaa";
   char * b = "bbbb";
   std::cout << a b;
}

此级联对所有编译器通用吗？ aaaa的零终止在哪里？

Is this concatenation common to all compilers? Where is the null termination of "aaaa"? Is "aaaabbbb" a continuous block of RAM?

推荐答案

如果看到例如此翻译阶段参考在第6阶段中确实做到了：

If you see e.g. this translation phase reference in phase 6 it does:

将相邻的字符串文字串联在一起。

Adjacent string literals are concatenated.

这就是这里发生的情况。您有两个相邻的字符串文字，它们被串联为一个字符串文字。

And that's exactly what happens here. You have two adjacent string literals, and they are concatenated into a single string literal.

这是标准行为。

它仅适用于字符串文字，不适用于两个指针变量。

It only works for string literals, not two pointer variables, as you noticed.

这篇关于字符串文字汇编的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！