Apple Mach-O Linker Warning direct access in ... to global weak symbol

Question

I'm using xcode 4.2 with ios 5.0 sdk building iphone app. Also, I import opencv library, and write some *.cpp codes with opencv functions. However, I got a lots similar "apple mach-o linker waring"

For instance -

ld: warning: direct access in __ZN15CvBlobTrackerCCC2Ev to global weak symbol __ZTV9CvBlobSeq means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.

ld: warning: direct access in __ZN18CvBlobTrackerAuto1C2EP23CvBlobTrackerAutoParam1 to global weak symbol __ZTV9CvBlobSeq means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.

How do I solve this? Thanks!

edit: just find out- xcode with boost : linker(Id) Warning about visibility settings

Holcombe

possible duplicate of xcode with boost : linker(Id) Warning about visibility settings – Collayer

Answer 1

Apple Mach-O Linker Warning comes in following cases

1.When the concerned file was not linked to target properly. 2.When the concerned file framework is not linked with code. 3.Replication of file so that compiler gets confusion

Please check your case against them.

If any one find any other reasons which I have not listed above please add it to the list.

Shroudlaid