> -----Original Message----- > From: gcc-help-owner@xxxxxxxxxxx [mailto:gcc-help-owner@xxxxxxxxxxx] On > Behalf Of Vijayaraghavan Murali > Sent: Tuesday, May 10, 2011 10:49 AM > To: gcc-help@xxxxxxxxxxx > Subject: RE: Live range information > > > > Thanks for your quick reply. Maybe I should have worded my question > better, > but I'm not looking for the scope of a variable but its live range. For > eg, > > main() { > <1> int a, b, c, d; > <2> b = a*2; > <3> c = b+3; > <4> d = c*b; > } > > Here the scope of a is the entire function, but its live range is only > till > 2, because it's not used after that. > > To restate my requirement to avoid confusion: for a program point, does > gcc > provide the list of variables live at it? Don't know for sure, but I would doubt that since finding that out equals a breadth-first search across the AST for each variable and further I can't imagine any use a optimizer could have for that information. Therefore it would be a useless operation that only consumes time for nothing. Someone correct me please if I'm wrong! :-) Anyway I'm only familiar with compiler/optimizer theory and not with the gcc implementation. If you feel to do so, you should peek at the sourcecode of gcc to find out more. > > Thanks! > > ------------------------- > Vijayaraghavan Murali > http://www.comp.nus.edu.sg/~mvijayar > > > > Dominik Psenner wrote: > > > > Hi > > > > The scope of variables is well defined in the abstract syntax tree > within > > gcc. Thus after gcc has parsed the code, you should be able to easily > > extract that information. > > > > Greetings, > > D. > > > >> -----Original Message----- > >> From: gcc-help-owner@xxxxxxxxxxx [mailto:gcc-help-owner@xxxxxxxxxxx] On > >> Behalf Of Vijayaraghavan Murali > >> Sent: Tuesday, May 10, 2011 9:33 AM > >> To: gcc-help@xxxxxxxxxxx > >> Subject: Live range information > >> > >> > >> Hi, > >> > >> I'm wondering if there is a way to make gcc dump variables' live range > >> information (using DWARF or otherwise). To be precise what I'm looking > >> for > >> is something like: 'a' is live from line 3 to 10, 'b' is live from line > 4 > >> to > >> 8, etc in some specified format. Is this possible in gcc? > >> > >> Thanks! > >> > >> ------------------------- > >> Vijayaraghavan Murali > >> http://www.comp.nus.edu.sg/~mvijayar > >> -- > >> View this message in context: http://old.nabble.com/Live-range- > >> information-tp31583370p31583370.html > >> Sent from the gcc - Help mailing list archive at Nabble.com. > > > > > > > > > > -- > View this message in context: http://old.nabble.com/Live-range- > information-tp31583370p31583805.html > Sent from the gcc - Help mailing list archive at Nabble.com.
