How to let the gtags support const definition search with emacs

Question

i use emacs for a long time, and also i use cscope for my code navigation, now i changed to global gtags, it is much advantage, like it is very fast, very precise to find the definition of a function, but i found it cannot find variable which defined by the "const", it always prompt the "tag not found", i have to use “find symbol” instead of “find definition”, but you know, i will got a lot search result, and i need to find out the definition from these so many results, so i just want to know whether there are some configration to let gtags support const definition search?