Nsight suddenly says " undefined reference to ..function"!!!

Hello, suddenly ,after running my program , the nsigh throws:

undefined reference to …function

.But my program :

  1. was running fine!
  2. runs fine from command line!

I did project clean but nothing!

How can I overcome this problem?
Is there any other solution?
A ‘deeper’ clean or something?


Hmm , it seems it wanted to add in a header:

#ifdef __cplusplus
#ifndef __CDT_PARSER__
	extern "C" {