diff options
Diffstat (limited to 'gdb/frame.c')
| -rw-r--r-- | gdb/frame.c | 40 |
1 files changed, 7 insertions, 33 deletions
diff --git a/gdb/frame.c b/gdb/frame.c index 1d37891..a7da919 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -1,7 +1,7 @@ /* Cache and manage frames for GDB, the GNU debugger. Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, - 2001, 2002, 2003 Free Software Foundation, Inc. + 2001, 2002, 2003, 2004 Free Software Foundation, Inc. This file is part of GDB. @@ -1726,7 +1726,12 @@ legacy_get_prev_frame (struct frame_info *this_frame) /* Return a structure containing various interesting information about the frame that called THIS_FRAME. Returns NULL - if there is no such frame. */ + if there is no such frame. + + This function tests some target-independent conditions that should + terminate the frame chain, such as unwinding past main(). It + should not contain any target-dependent tests, such as checking + whether the program-counter is zero. */ struct frame_info * get_prev_frame (struct frame_info *this_frame) @@ -1943,37 +1948,6 @@ get_prev_frame (struct frame_info *this_frame) prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info); prev_frame->level = this_frame->level + 1; - /* Try to unwind the PC. If that doesn't work, assume we've reached - the oldest frame and simply return. Is there a better sentinal - value? The unwound PC value is then used to initialize the new - previous frame's type. - - Note that the pc-unwind is intentionally performed before the - frame chain. This is ok since, for old targets, both - frame_pc_unwind (nee, FRAME_SAVED_PC) and - DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures - have already been initialized (using - DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order - doesn't matter. - - By unwinding the PC first, it becomes possible to, in the case of - a dummy frame, avoid also unwinding the frame ID. This is - because (well ignoring the PPC) a dummy frame can be located - using THIS_FRAME's frame ID. */ - - if (frame_pc_unwind (this_frame) == 0) - { - /* The allocated PREV_FRAME will be reclaimed when the frame - obstack is next purged. */ - if (frame_debug) - { - fprintf_unfiltered (gdb_stdlog, "-> "); - fprint_frame (gdb_stdlog, NULL); - fprintf_unfiltered (gdb_stdlog, " // unwound PC zero }\n"); - } - return NULL; - } - /* Don't yet compute ->unwind (and hence ->type). It is computed on-demand in get_frame_type, frame_register_unwind, and get_frame_id. */ |