C++ files end with .c can not addressed by global

[Rong Yue]

Hi,

 In my working environment, C++ files are ending in .c.h. When I use 
gtags, all class definitions are not listed. I tried to set ~/.globalrc, 
but then when I use gtags, it complaints

gtags: label 'default' not found.

Please help!

Thanks,

-Rong