Hello Gnu Global,
I was wondering if it would be hard to modify gtags so that it would remember the references (for variables) as being "modified/written" or being "read". Then, global can, possibly with a flag show us just the references that are modifying a variable or just reading the variable or either/other (such as the symbol's presence in declaration of a function, or definition in a class/struct.)
I tried to look at gtags.c, but I could not frankly make enough sense to know just how to go about this. It seems schema of GRTAGS db would have to change a bit to add at least a column for "type_of_symbol_reference"?