{
/* We're doing a "next". */
- if (pc_in_sigtramp (stop_pc)
+ if (legacy_frame_p (current_gdbarch)
+ && pc_in_sigtramp (stop_pc)
&& frame_id_inner (step_frame_id,
frame_id_build (read_sp (), 0)))
- /* We stepped out of a signal handler, and into its
- calling trampoline. This is misdetected as a
- subroutine call, but stepping over the signal
- trampoline isn't such a bad idea. In order to do that,
- we have to ignore the value in step_frame_id, since
- that doesn't represent the frame that'll reach when we
- return from the signal trampoline. Otherwise we'll
- probably continue to the end of the program. */
+ /* NOTE: cagney/2004-03-15: This is only needed for legacy
+ systems. On non-legacy systems step_over_function doesn't
+ use STEP_FRAME_ID and hence the below update "hack" isn't
+ needed. */
+ /* We stepped out of a signal handler, and into its calling
+ trampoline. This is misdetected as a subroutine call, but
+ stepping over the signal trampoline isn't such a bad idea.
+ In order to do that, we have to ignore the value in
+ step_frame_id, since that doesn't represent the frame
+ that'll reach when we return from the signal trampoline.
+ Otherwise we'll probably continue to the end of the
+ program. */
step_frame_id = null_frame_id;
step_over_function (ecs);
However, if the callee is recursing, we want to be careful not to
catch returns of those recursive calls, but only of THIS instance
- of the call.
+ of the caller.
To do this, we set the step_resume bp's frame to our current
- caller's frame (step_frame_id, which is set by the "next" or
- "until" command, before execution begins). */
+ caller's frame (obtained by doing a frame ID unwind). */
static void
step_over_function (struct execution_control_state *ecs)
check_for_old_step_resume_breakpoint ();
- if (frame_id_p (step_frame_id)
- && !IN_SOLIB_DYNSYM_RESOLVE_CODE (sr_sal.pc))
- /* NOTE: cagney/2004-02-27: Use the global state's idea of the
- stepping frame ID. I suspect this is done as it is lighter
- weight than a call to get_prev_frame. */
- sr_id = step_frame_id;
- else if (legacy_frame_p (current_gdbarch))
- /* NOTE: cagney/2004-02-27: This is the way it was 'cos this is
- the way it always was. It should be using the unwound (or
- caller's) ID, and not this (or the callee's) ID. It appeared
- to work because: legacy architectures used the wrong end of the
- frame for the ID.stack (inner-most rather than outer-most) so
- that the callee's id.stack (un adjusted) matched the caller's
- id.stack giving the "correct" id; more often than not
- !IN_SOLIB_DYNSYM_RESOLVE_CODE and hence the code above (it was
- originally later in the function) fixed the ID by using global
- state. */
- sr_id = get_frame_id (get_current_frame ());
+ /* NOTE: cagney/2004-03-15: Code using the current value of
+ "step_frame_id", instead of unwinding that frame ID, removed (at
+ least for non-legacy platforms). On s390 GNU/Linux, after taking
+ a signal, the program is directly resumed at the signal handler
+ and, consequently, the PC would point at at the first instruction
+ of that signal handler but STEP_FRAME_ID would [incorrectly] at
+ the interrupted code when it should point at the signal
+ trampoline. By always and locally doing a frame ID unwind, it's
+ possible to assert that the code is always using the correct
+ ID. */
+ if (legacy_frame_p (current_gdbarch))
+ {
+ if (frame_id_p (step_frame_id)
+ && !IN_SOLIB_DYNSYM_RESOLVE_CODE (sr_sal.pc))
+ /* NOTE: cagney/2004-02-27: Use the global state's idea of the
+ stepping frame ID. I suspect this is done as it is lighter
+ weight than a call to get_prev_frame. */
+ /* NOTE: cagney/2004-03-15: See comment above about how this
+ is also broken. */
+ sr_id = step_frame_id;
+ else
+ /* NOTE: cagney/2004-03-15: This is the way it was 'cos this
+ is the way it always was. It should be using the unwound
+ (or caller's) ID, and not this (or the callee's) ID. It
+ appeared to work because: legacy architectures used the
+ wrong end of the frame for the ID.stack (inner-most rather
+ than outer-most) so that the callee's id.stack (un
+ adjusted) matched the caller's id.stack giving the
+ "correct" id; more often than not
+ !IN_SOLIB_DYNSYM_RESOLVE_CODE and hence the code above (it
+ was originally later in the function) fixed the ID by using
+ global state. */
+ sr_id = get_frame_id (get_current_frame ());
+ }
else
sr_id = get_frame_id (get_prev_frame (get_current_frame ()));
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