Implement gdbarch_stack_frame_destroyed_p for aarch64
The internal AdaCore testsuite has a test that checks that an
out-of-scope watchpoint is deleted. This fails on some aarch64
configurations, reporting an extra stop:
(gdb) continue
Continuing.
Thread 3 hit Watchpoint 2: result
Old value = 64
New value = 0
0x0000000040021648 in pck.get_val (seed=0, off_by_one=false) at [...]/pck.adb:13
13 end Get_Val;
I believe what is happening here is that the variable is stored at:
<efa> DW_AT_location : 2 byte block: 91 7c (DW_OP_fbreg: -4)
and the extra stop is reported just before a return, when the ldp
instruction is executed:
0x0000000040021644 <+204>: ldp x29, x30, [sp], #48
0x0000000040021648 <+208>: ret
This instruction modifies the frame base calculation, and so the test
picks up whatever memory is pointed to in the callee frame.
Implementing the gdbarch hook gdbarch_stack_frame_destroyed_p fixes
this problem.
As usual with this sort of patch, it has passed internal testing, but
I don't have a good way to try it with dejagnu. So, I don't know
whether some existing test covers this. I suspect there must be one,
but it's also worth noting that this test passes for aarch64 in some
configurations -- I don't know what causes one to fail and another to
succeed.
1 file changed
