前置處理器
Definition
5.1.1.1 Program structure p1:
A C program need not all be translated at the same time.
The text of the program is kept in units called source files, (or preprocessing files) in this International Standard.
在ISO, 程式的文本是由
source file
(orpreprocessing file
)為單位所組成。
A source file together with all the headers and source files included via the preprocessing directive #include is known as a preprocessing translation unit. After preprocessing, a preprocessing translation unit is called a translation unit.
一個source file是透過preprocessing directive
#
將其從preprocessing translation unit 轉譯成 translation unit
External Declaration
),headers和source files包含進來。包含進來的方式有:
#include
directive將header
的內容貼到translation unit中。History
在ISO C之前早期的C 語言編譯器, 發展於1972-1973 年間,被稱為 “Very early C compilers” 的實作中,不存在 C preprocessor (!)