【C语言常识】mdk:Pragmas recognized by the compiler

た入场券 2022-06-16 06:43 324阅读 0赞

出处：官方编译器手册

See the following topics in the *Compiler Reference*:

Pragmas for saving and restoring the pragma state

*  *\#pragma pop*
 *  *\#pragma push*.

Pragmas controlling optimization goals

*  *\#pragma Onum*
 *  *\#pragma Ospace*
 *  *\#pragma Otime*.

Pragmas controlling code generation

*  *\#pragma arm*
 *  *\#pragma thumb*
 *  *\#pragma exceptions\_unwind, \#pragma no\_exceptions\_unwind*.

Pragmas controlling loop unrolling:

*  *\#pragma unroll \[(n)\]*
 *  *\#pragma unroll\_completely*.

Pragmas controlling *`PreCompiled Header`* (PCH) processing

*  *\#pragma hdrstop*
 *  *\#pragma no\_pch*.

Pragmas controlling anonymous structures and unions

*  *\#pragma anon\_unions, \#pragma no\_anon\_unions*.

Pragmas controlling diagnostic messages

*  *\#pragma diag\_default tag\[,tag,...\]*
 *  *\#pragma diag\_error tag\[,tag,...\]*
 *  *\#pragma diag\_remark tag\[,tag,...\]*
 *  *\#pragma diag\_suppress tag\[,tag,...\]*
 *  *\#pragma diag\_warning tag\[, tag, ...\]*.

Miscellaneous pragmas

*  *\#pragma arm section \[section\_type\_list\]*
 *  *\#pragma import(\_\_use\_full\_stdio)*
 *  *\#pragma inline, \#pragma no\_inline*
 *  *\#pragma once*
 *  *\#pragma pack(n)*
 *  *\#pragma softfp\_linkage, \#pragma no\_softfp\_linkage*
 *  *\#pragma import symbol\_name*.

其中，有一个可以定义具体某个函数的优化级

\#pragma Onum  
  
This pragma changes the optimization level.  
  
\#pragma Onum  
where:  
  
num  
is the new optimization level.  
The value of num is 0, 1, 2 or 3.  
This pragma enables you to assign optimization levels to individual functions.  
The pragma must be placed outside the function.  
  
  
  
\#pragma Ospace  
This pragma instructs the compiler to perform optimizations to reduce image size at the expense of a possible increase in execution time.  
This pragma enables you to assign optimization goals to individual functions.  
The pragma must be placed outside the function.  
  
  
\#pragma Otime  
This pragma instructs the compiler to perform optimizations to reduce execution time at the expense of a possible increase in image size.  
This pragma enables you to assign optimization goals to individual functions.  
The pragma must be placed outside the function.

2018.02.12

有时候用别的人库，偶尔会有一些警告，虽然不妨碍用，但是看着不爽，还不想动被人的库，怎么办呢？有命令可以屏蔽掉

这个警告，看着舒服些。

\--diag\_suppress=61,68,550,767,111

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[20180212162542680]: /images/20220616/ac8f9b49543d430483e35ac6d0feae30.png