using Carbon api on mac error:Undefined symbols for architecture x86_64

[fong]

Hi

I'm using Qt5.3(qt-opensource-mac-x64-clang-5.3.1.dmg) on mac os x 10.10.1,xcode6

I need to use the GetKeys() in carbon in a staticlib,so I did the following:
1).add header file in .cpp

#include <Carbon/Carbon.h>

#include <Carbon/Carbon.h>

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2).add framework include in xxx.pro

LIBS += -framework Carbon

LIBS += -framework Carbon

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mylib compiles ok,but when myapp to link the lib, it throws error:

Undefined symbols for architecture x86_64:
  "_GetKeys", referenced from:
      Platform::get_keyboard_modifiers() in libxxx.a(platform.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Undefined symbols for architecture x86_64:
  "_GetKeys", referenced from:
      Platform::get_keyboard_modifiers() in libxxx.a(platform.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

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I've tryed to add QMAKE_LFLAGS += -L/System/Library/Frameworks/Carbon in xxx.pro,but it didn't work.

can anyone tell me why,or is there a way in Qt to take the place of Carbon/GetKeys()?
Thanks