How to supress warning on the line on Objective-C compiler?

Question

How to supress a warning on the line on Objective-C compiler?

...
[[UIWebDocumentView class] jr_swizzleMethod:@selector(canPerformAction:withSender:) withMethod:@selector(myCanPerformAction:withSender:) error:nil]; // warning here
...

NSObject has this method (as category). But compiler thinks that UIWebDocumentView doesn't. This is a compiller's issue. Is there any directive to suppress warnings on a block of the code?

The warning:

Receiver 'UIWebDocumentView' is a forward class and corresponding @interface may not exist

P.S. UIWebDocumentView is a private API - so can't use performSelector method tu supress the warning.

Please your question and add the line and the **exact warning text**. — Adam Rosenfield, Nov 08 '12 at 18:04
[@selector - With Multiple Arguments?](http://stackoverflow.com/questions/2297613/selector-with-multiple-arguments) — Black Frog, Nov 08 '12 at 18:10
Suppressing the warning is the wrong thing to do much of the time. The *correct* fix is to make sure you're `#import`ing the correct header files so that the compiler is aware of the category. — Adam Rosenfield, Nov 08 '12 at 18:15

score 4 · Answer 1 · answered Nov 08 '12 at 18:17

4

Generally, you can ignore warnings for a single line of code like this:

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
[foo bar];
#pragma clang diagnostic pop

replace -Warc-performSelector-leaks with the actual warning.

Since you didn't post the exact warning you have to figure out the -WarnLevel on your own.

answered Nov 08 '12 at 18:17

Matthias Bauch

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I have added the actual warning to the question. – Dmitry Nov 08 '12 at 18:22
The warning is: `Receiver 'UIWebDocumentView' is a forward class and corresponding @interface may not exist.` – Dmitry Nov 08 '12 at 18:25

score 2 · Accepted Answer · answered Nov 08 '12 at 18:55

2

The easiest way to fix this is just to get the class a different way:

[NSClassFromString(@"UIWebDocumentView") jr_swizzleMethod:@selector(canPerformAction:withSender:) withMethod:@selector(myCanPerformAction:withSender:) error:nil]; // warning here

answered Nov 08 '12 at 18:55

rob mayoff

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How to supress warning on the line on Objective-C compiler?

2 Answers2