#pragma warn Macro Directive in C | Suppress Warning Messages

Topics : How to Suppress Warning Messages in C ?

1. What is Warning Message in C ?
2. What is Error and Message in C ?
3. #pragma warn Directive in C
4. Live Example
5. List of Warning Codes in ANSI

Warning Message :

• A warning is a non-critical condition that does not require immediate attention.
• Warning can be ignored.
• Waring will never stop your execution of C Program.

Error Message

• An Error is a critical condition that requires immediate attention.
• Error messages cannot be ignored.
• Compile Error won’t let you to run C Program.
• run Time Error will terminate current execution of C program

#pragma warn Macro Directive in C

1. In c there are many warning messages which can be on or off with help of #pragma warn.

Syntax :

#pragma warn +xxx
#pragma warn –xxx
#pragma warn .xxx

Where

+ means on
- means off
. means on/off (toggle)

1. xxx is indicate particular warning code in thee alphabet.
2. Example : rvl warning code means function should return a value.

Live Example :

#include<stdio.h>
#pragma warn –rvl
int main(){
printf("It will not show any warning message");
}

Explanation :

1. -rvl mean suppress warning message .
2. rvl means : “Function should return a value“.
3. We have specified return type of main as “Integer” but we are not going to return a value.
4. Usually this program will show warning message.
5. We have suppressed warning already (-rvl) so we won’t get any warning message.
6. Standard notation and there actual meaning is shown inside following table -

List of Warning Codes in C