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Re: RFC: Mostly kill FRAME_CHAIN_VALID, add user knob
- From: Andrew Cagney <ac131313 at redhat dot com>
- To: Daniel Jacobowitz <drow at mvista dot com>
- Cc: gdb-patches at sources dot redhat dot com
- Date: Fri, 10 Jan 2003 15:10:35 -0500
- Subject: Re: RFC: Mostly kill FRAME_CHAIN_VALID, add user knob
- References: <20021226191541.GA8483@nevyn.them.org>
FYI, on the unwind branch, I'm adding the below to get_prev_frame()
/* There is always a frame. If this assertion fails, suspect that
something should be calling get_selected_frame() or
gdb_assert (next_frame != NULL);
if (next_frame->level >= 0
/* && !backtrace_below_main */
&& inside_main_func (next_frame->pc))
/* Don't unwind past main(), always unwind the sentinel frame.
Note, this is done _before_ the frame has been marked as
previously unwound. That way if the user later decides to
allow unwinds past main(), it can just happen. */
/* Only try to do the unwind once. */
next_frame->prev_p = 1;
Should eliminate that need to flush the frame cache everytime that
command is issued (should be able to merge it into current code as well).
Looking at the other checks:
/* If we're already inside the entry function for the main objfile,
then it isn't valid. */
if (inside_entry_func (get_frame_pc (fi)))
I'd better add that one as well (but, I think, after ->prev_p). Note
that this and the test below do the same thing, so only one is needed.
It is just that one stops things a frame later.
/* If we're inside the entry file, it isn't valid. */
/* NOTE/drow 2002-12-25: should there be a way to disable this check?
it assumes a single small entry file, and the way some debug readers
(e.g. dbxread) figure out which object is the entry file is somewhat
if (inside_entry_file (frame_pc_unwind (fi)))
Should this one be dropped? If the user specified unwind past main,
then they problably want _start() included in the backtrace. It's
presence also makes the other inside_entry_file() test redundant.
PS: The command/variable should be `backtrace-*above*-main', or perhaphs
`backtrace-before-main' (before ~= prev).