g ++ -E选项输出 [英] g++ -E option output

问题描述

使用此选项，我在预处理后接收文件。有很多行：

 ＃91/usr/include/stdint.h3 4 
  

这些数字是什么意思？首先我认为＃91 是包含文件的行数，但不是它。 $ 3 要官方文档，该行的格式为：

 ＃linenum档案名称标志
  

linenum 指定以下行源自 filename 在该行号。然后有四个标志：

• 1 - 开始一个新文件
• 
  
• 2 - 返回档案


• 3 - 系统头文件


• 4 - 视为包装在 externC code>



所以让我们来解释你的linemarker：

 ＃91/usr/include/stdint.h3 4 
  

以下行源自 /usr/include/stdint.h 的第91行。它是一个系统头文件，应该被视为包装在 externC。

Using this option I receive files after preprocessing. There are many lines like:

# 91 "/usr/include/stdint.h" 3 4

What do the numbers mean? First I thought that #91 is the number of line where file is included, but that is not it. And about 3 4 I have no idea at all.

解决方案

According to the official documentation, the line is of the format:

# linenum filename flags

The linenum specifies that the following line originated in filename at that line number. Then there are four flags:

• 1 - Start of a new file
• 2 - Returning to a file
• 3 - System header file
• 4 - Treat as being wrapped in extern "C"

So let's interpret your linemarker:

# 91 "/usr/include/stdint.h" 3 4

The following line originated from line 91 of /usr/include/stdint.h. It is a system header file and should be treated as wrapped in extern "C".

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