where is the definition of struct gcc_options?

[zet]

Hello, All

I am reading the source of gcc(version 4.8.2), there is a important
symbol 'global_options' whose type is struct gcc_options
in cc1' entry function toplev_main().

I have build the gcc with make -g -O0, in gdb use ptype i can get the
content of struct gcc_options,
but in vim I cannot find its definition.

$ ctags -R/ cscope -R

And other symbol jump is correct, just struct gcc_options.
Did I missing something?

thx

-- 
业精于勤,荒于嬉.