I've noticed that if I compile my C++ programs using (a recent Debian
snapshot of) the gcc trunk [0], and try to debug the resulting
program, then I've noticed (there are no doubt other issues):
(1) gdb doesn't seem to know about most local variables / function
parameters: trying to print them by name doesn't work ("No
symbol ... in current context); "i loc" and "i args" show nothing.
(2) gdb can't find many functions in my program: referring to them
by name doesn't work,and searching using "i fun ..." with an
appropriate pattern gives nothing.
(3) When printing backtraces, etc, gdb spits out warnings like:
warning: (Internal error: pc 0x429e7a in read in psymtab, but not in symtab.)
(4) Backtraces sometimes seem to be missing frames that I don't
think are due to inlining/tail-calls/whatever.
I.e., things are fairly clearly "messed up."
This behavior seems to be the case no matter what optimization flags I
use (from no -O flag at all, to -O3; I always use -g).
If I recompile my program using gcc 4.7, then gdb works as expected
(local variables, functions, no warnings spat, etc). This is true
regardless of optimization level.
Is there some change in trunk gcc that requires a newer gdb or something...?
gcc snapshot version (has the problems):
gcc (Debian 20130123-1) 4.8.0 20130123 (experimental) [trunk revision 195409]
gdb normal version (no problems)
gcc (Debian 4.7.2-5) 4.7.2
gdb version:
GNU gdb (GDB) 7.4.1-debian
Thanks,
-miles
--
"Whatever you do will be insignificant, but it is very important that
you do it." Mahatma Gandhi
