diff options
Diffstat (limited to 'gdb/frame.c')
| -rw-r--r-- | gdb/frame.c | 140 |
1 files changed, 78 insertions, 62 deletions
diff --git a/gdb/frame.c b/gdb/frame.c index 900b51518c5..847226a12bc 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -53,17 +53,50 @@ static int backtrace_below_main; struct frame_id get_frame_id (struct frame_info *fi) { + struct frame_id id; if (fi == NULL) { + /* Should never happen! */ return null_frame_id; } - else + if (!fi->id_p) { - struct frame_id id; - id.base = fi->frame; - id.pc = fi->pc; - return id; + gdb_assert (!legacy_frame_p (current_gdbarch)); + + /* Find THIS frame's ID. */ + fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->id); + fi->id_p = 1; + + /* Check that the unwound ID is valid. */ + if (!frame_id_p (fi->id) && frame_debug) + fprintf_unfiltered (gdb_stdlog, + "Unwound frame ID invalid\n"); + + /* Check that the new frame isn't inner to (younger, below, next) + the old frame. If that happens the frame unwind is going + backwards. */ + /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since + that doesn't have a valid frame ID. Should instead set the + sentinel frame's frame ID to a true `sentinel'. Leave it + until after the switch to storing the frame ID, instead of + the frame base, in the frame object. */ + if (fi->level >= 0 && frame_id_p (fi->id) && fi->next->id_p + && frame_id_inner (fi->id, get_frame_id (fi->next))) + error ("Unwound frame inner-to selected frame (corrupt stack?)"); + + /* Note that, due to frameless functions, the stronger test of + the new frame being outer to the old frame can't be used - + frameless functions differ by only their PC value. */ + + /* FIXME: cagney/2002-12-18: Instead of this hack, should only + store the frame ID in PREV_FRAME. Unfortunatly, some + architectures (HP/UX) still reply on EXTRA_FRAME_INFO and, + hence, still poke at the "struct frame_info" object directly. */ + fi->frame = fi->id.base; } + id.base = fi->frame; + id.pc = fi->pc; + return id; } const struct frame_id null_frame_id; /* All zeros. */ @@ -1452,6 +1485,39 @@ get_prev_frame (struct frame_info *this_frame) return NULL; } + /* If THIS frame ended up with a NULL frame ID, don't bother trying + to unwind it. */ + if (this_frame->level >= 0 && !frame_id_p (get_frame_id (this_frame))) + { + if (frame_debug) + fprintf_filtered (gdb_stdlog, + "Outermost frame - next ID is NULL\n"); + return NULL; + } + + /* Check that THIS frame isn't inner to (younger, below, next) the + NEXT frame. If that happens the frame unwind went backwards. */ + /* FIXME: cagney/2003-02-25: Instead of ignoring the sentinel frame + (since that doesn't have a valid frame ID), the code should set + the sentinel frame's frame ID to a true `sentinel'. Leave it + until after the switch to storing the frame ID, instead of the + frame base, in the frame object. */ + if (this_frame->level > 0 + && frame_id_inner (get_frame_id (this_frame), + get_frame_id (this_frame->next))) + error ("This frame inner-to next frame (corrupt stack?)"); + + /* Check that THIS and NEXT frame are different. If they are not, + there is most likely a stack cycle. */ + /* FIXME: cagney/2003-03-17: Can't yet do this check. The + frame_id_eq() method doesn't yet use function addresses when + comparing IDs. */ + if (0 + && this_frame->level > 0 + && frame_id_eq (get_frame_id (this_frame), + get_frame_id (this_frame->next))) + error ("This frame identical to next frame (corrupt stack?)"); + /* If any of the old frame initialization methods are around, use the legacy get_prev_frame method. */ if (legacy_frame_p (current_gdbarch)) @@ -1509,63 +1575,7 @@ get_prev_frame (struct frame_info *this_frame) prev_frame->unwind = frame_unwind_find_by_pc (current_gdbarch, prev_frame->pc); - /* Find the prev's frame's ID. */ - - /* The callee expects to be invoked with: - - this->unwind->this_id (this->next, &this->cache, &this->id); - - The below is carefully shifted one frame `to the left' so that - both the unwind->this_id and unwind->prev_register methods are - consistently invoked with NEXT_FRAME and THIS_PROLOGUE_CACHE. - - Also note that, while the PC for this new previous frame was - unwound first (see above), the below is the first call that - [potentially] requires analysis of the new previous frame's - prologue. Consequently, it is this call, that typically ends up - initializing the previous frame's prologue cache. */ - prev_frame->unwind->this_id (this_frame, - &prev_frame->prologue_cache, - &prev_frame->id); - - /* Check that the unwound ID is valid. */ - if (!frame_id_p (prev_frame->id)) - { - if (frame_debug) - fprintf_unfiltered (gdb_stdlog, - "Outermost frame - unwound frame ID invalid\n"); - return NULL; - } - - /* Check that the new frame isn't inner to (younger, below, next) - the old frame. If that happens the frame unwind is going - backwards. */ - /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since that - doesn't have a valid frame ID. Should instead set the sentinel - frame's frame ID to a true `sentinel'. Leave it until after the - switch to storing the frame ID, instead of the frame base, in the - frame object. */ - if (this_frame->level >= 0 - && frame_id_inner (prev_frame->id, get_frame_id (this_frame))) - error ("Unwound frame inner-to selected frame (corrupt stack?)"); - - /* FIXME: cagney/2003-03-14: Should check that this and next frame's - IDs are different (i.e., !frame_id_eq()). Can't yet do that as - the EQ function doesn't yet compare PC values. */ - - /* FIXME: cagney/2003-03-14: Should delay the evaluation of the - frame ID until when it is needed. That way the inner most frame - can be created without needing to do prologue analysis. */ - - /* Note that, due to frameless functions, the stronger test of the - new frame being outer to the old frame can't be used - frameless - functions differ by only their PC value. */ - - /* FIXME: cagney/2002-12-18: Instead of this hack, should only store - the frame ID in PREV_FRAME. Unfortunatly, some architectures - (HP/UX) still reply on EXTRA_FRAME_INFO and, hence, still poke at - the "struct frame_info" object directly. */ - prev_frame->frame = prev_frame->id.base; + /* The PREV's frame ID is computed on-demand in get_frame_id(). */ /* Link it in. */ this_frame->prev = prev_frame; @@ -1608,6 +1618,12 @@ find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal) CORE_ADDR get_frame_base (struct frame_info *fi) { + if (!fi->id_p) + { + /* Force the ID code to (indirectly) initialize the ->frame + pointer. */ + get_frame_id (fi); + } return fi->frame; } |