suppress instance method override linker warning f

问题:

I have a library that started throwing a couple linker warnings under XCode 4.4. The warnings are along the lines of "ld: warning: instance method 'methodName:' in category from overrides method from class in "

The framework still work fine, and I assume the company that wrote it will correct this in the next release, but for the time being these warnings are very annoying. Is there any way to turn them off without disabling all linker warnings?

回答1:

There are two options I have come up with by adding flags to "Other Linker Flags" in the Xcode build settings area:

1) Adding -Xlinker -w will suppress all linker warnings, no matter the type (this is the -w flag to ld(1)). Obviously that will quiet this particular warning, but all other ld warnings as well.

2) Adding -Xlinker -no_objc_category_merging will skip the optimization step where the linker combines all category methods into the base class during linking, which would then occur at runtime instead. Tiny bit slower on startup probably, but it would probably still be faster than method swizzling at runtime, and since it is during this step that ld(1) issues the warning, it will skip that too.

It appears that ld does not have a way to surgically suppress any individual warning the way the compiler does, although it has specialty flags for a couple of them or groups of them (none of which help with this one). Neither solution above is probably recommended for production code, but in some situations, one or the other might help.

回答2:

If an option for hiding that warning exists it would be under:

Project Navigator(the file list on the left )-> [Project name](the one with the blue icon) -> Build Settings -> Apple LLVM compiler 3.1 - Warnings

Also:

In Xcode, how to suppress all warnings in specific source files?