https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38534
--- Comment #36 from Lukas Grätz <[email protected]> --- (In reply to Jakub Jelinek from comment #35) > If I hand edit the gcc trunk + PR114116 patch assembly, add to bar > + .cfi_undefined 3 > + .cfi_undefined 12 > + .cfi_undefined 13 > + .cfi_undefined 14 > + .cfi_undefined 15 > then bt in gdb shows > #2 0x00000000004011d2 in baz (a=a@entry=42, b=b@entry=43, c=c@entry=44, > d=<error reading variable: value has been optimized out>, > e=<error reading variable: value has been optimized out>, f=<error > reading variable: value has been optimized out>, g=48, h=49) at /tmp/1.c:38 I can confirm that. What bothers me, is the wording "d=<error .... optimized out>" and not just "d=<optimized out>". (gdb) run Starting program: bar-artificial-mod Program received signal SIGABRT, Aborted. (gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x00007ffff7dcd859 in __GI_abort () at abort.c:79 #2 0x00000000004011b1 in bar () at bar-artificial.c:30 #3 0x00000000004011d2 in baz (a=a@entry=42, b=b@entry=43, c=c@entry=44, d=<error reading variable: value has been optimised out>, e=<error reading variable: value has been optimised out>, f=<error reading variable: value has been optimised out>, g=48, h=49) at bar-artificial.c:38 #4 0x00000000004012aa in qux () at bar-artificial.c:55 #5 0x00000000004012e4 in main () at bar-artificial.c:62 (gdb) p a No symbol "a" in current context. (gdb) p b No symbol "b" in current context. > and everything in qux live across the call is <optimized out> as well, > (gdb) p $r12 > $10 = <not saved> > etc. while without that > (gdb) p a > $1 = <optimized out> > (gdb) p b > $2 = <optimized out> > (gdb) p c > $3 = <optimized out> > (gdb) p d > $4 = -559038737 > (gdb) p e > $5 = -559038737 > (gdb) p f > $6 = -559038737 > (gdb) p g > $7 = -559038737 > (gdb) p h > $8 = -559038737 > (gdb) p $r12 > $9 = 3735928559 Where did you set the breakpoint? When I set it somewhere in qux (after a,b,c,... were initialized), I get conclusive results: (gdb) break bar-artificial.c:52 Breakpoint 1 at 0x40124a: file bar-artificial.c, line 52. (gdb) run Breakpoint 1, qux () at bar-artificial.c:52 52 corge (__builtin_alloca (foo (52))); (gdb) p a $1 = 42 (gdb) p b $2 = 43 (gdb) p c $3 = 44 (gdb) p d $4 = 45 (gdb) p e $5 = 46 (gdb) p f $6 = 47 (gdb) p g $7 = 48 (gdb) p h $8 = 49 (gdb) p $r12 $9 = 46
