6dc42492b6
Fix frame off-by-one bug. * frame-unwind.h (frame_this_id_ftype): Replace frame_unwind_id_ftype. (frame_prev_register_ftype): Replace frame_unwind_reg_ftype. (struct frame_unwind): Replace "id" with "this_id". Replace "reg" with "prev_register". * frame-unwind.c (frame_unwind_find_by_pc): Return legacy_saved_regs_unwind instead of trad_frame_unwind. Update comment. * dummy-frame.c (cached_find_dummy_frame): Delete function. (dummy_frame_this_id): Replace dummy_frame_id_unwind. (dummy_frame_prev_register): Replace dummy_frame_register_unwind. (dummy_frame_unwind): Update. * sentinel-frame.c (sentinel_frame_prev_register): Replace sentinel_frame_register_unwind. (sentinel_frame_this_id): Replace sentinel_frame_id_unwind. (sentinel_frame_unwinder): Update. * frame.h (legacy_saved_regs_unwind): Replace trad_frame_unwind. (struct frame_info): Rename "unwind_cache" to "prologue_cache". * frame.c (create_sentinel_frame): Update. Initialize "prologue_cache" instead of "unwind_cache". (frame_register_unwind): Call this frame's prev_register with the next frame and this frame's prologue cache. (get_prev_frame): Simplify. Always call prev frame's this_id with this frame and prev frame's prologue cache. Document that this call is shifted one to the left when compared to the frame_register_unwind call. (legacy_saved_regs_prev_register): Replace frame_saved_regs_register_unwind. (legacy_saved_regs_this_id): Replace frame_saved_regs_id_unwind. (legacy_saved_regs_unwinder): Replace trad_frame_unwinder. (legacy_saved_regs_unwind): Replace trad_frame_unwind. * d10v-tdep.c (d10v_frame_this_id): Replace d10v_frame_id_unwind. (d10v_frame_unwind): Update. (d10v_frame_prev_register): Replace d10v_frame_register_unwind. (d10v_frame_unwind_cache): Replace this "fi" with "next_frame". (saved_regs_unwinder): Replace this "frame" with "next_frame", and "saved_regs" with "this_saved_regs".
138 lines
5.4 KiB
C
138 lines
5.4 KiB
C
/* Definitions for a frame unwinder, for GDB, the GNU debugger.
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Copyright 2003 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#if !defined (FRAME_UNWIND_H)
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#define FRAME_UNWIND_H 1
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struct frame_info;
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struct frame_id;
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struct frame_unwind;
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struct gdbarch;
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struct regcache;
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/* Return the frame unwind methods for the function that contains PC,
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or NULL if this this unwinder can't handle this frame. */
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typedef const struct frame_unwind *(frame_unwind_p_ftype) (CORE_ADDR pc);
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/* Add a frame unwinder to the list. The predicates are polled in the
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order that they are appended. The initial list contains the dummy
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frame's predicate. */
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extern void frame_unwind_append_predicate (struct gdbarch *gdbarch,
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frame_unwind_p_ftype *p);
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/* Iterate through the list of frame unwinders until one returns an
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implementation. */
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extern const struct frame_unwind *frame_unwind_find_by_pc (struct gdbarch
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*gdbarch,
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CORE_ADDR pc);
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/* The following unwind functions assume a chain of frames forming the
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sequence: (outer) prev <-> this <-> next (inner). All the
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functions are called with called with the next frame's `struct
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frame_info' and and this frame's prologue cache.
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THIS frame's register values can be obtained by unwinding NEXT
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frame's registers (a recursive operation).
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THIS frame's prologue cache can be used to cache information such
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as where this frame's prologue stores the previous frame's
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registers. */
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/* Assuming the frame chain: (outer) prev <-> this <-> next (inner);
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use the NEXT frame, and its register unwind method, to determine
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the frame ID of THIS frame.
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A frame ID provides an invariant that can be used to re-identify an
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instance of a frame. It is a combination of the frame's `base' and
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the frame's function's code address.
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Traditionally, THIS frame's ID was determined by examining THIS
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frame's function's prologue, and identifying the register/offset
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used as THIS frame's base.
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Example: An examination of THIS frame's prologue reveals that, on
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entry, it saves the PC(+12), SP(+8), and R1(+4) registers
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(decrementing the SP by 12). Consequently, the frame ID's base can
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be determined by adding 12 to the THIS frame's stack-pointer, and
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the value of THIS frame's SP can be obtained by unwinding the NEXT
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frame's SP.
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THIS_PROLOGUE_CACHE can be used to share any prolog analysis data
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with the other unwind methods. Memory for that cache should be
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allocated using frame_obstack_zalloc(). */
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typedef void (frame_this_id_ftype) (struct frame_info *next_frame,
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void **this_prologue_cache,
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struct frame_id *this_id);
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/* Assuming the frame chain: (outer) prev <-> this <-> next (inner);
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use the NEXT frame, and its register unwind method, to unwind THIS
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frame's registers (returning the value of the specified register
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REGNUM in the previous frame).
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Traditionally, THIS frame's registers were unwound by examining
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THIS frame's function's prologue and identifying which registers
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that prolog code saved on the stack.
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Example: An examination of THIS frame's prologue reveals that, on
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entry, it saves the PC(+12), SP(+8), and R1(+4) registers
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(decrementing the SP by 12). Consequently, the value of the PC
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register in the previous frame is found in memory at SP+12, and
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THIS frame's SP can be obtained by unwinding the NEXT frame's SP.
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Why not pass in THIS_FRAME? By passing in NEXT frame and THIS
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cache, the supplied parameters are consistent with the sibling
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function THIS_ID.
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Can the code call ``frame_register (get_prev_frame (NEXT_FRAME))''?
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Won't the call frame_register (THIS_FRAME) be faster? Well,
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ignoring the possability that the previous frame does not yet
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exist, the ``frame_register (FRAME)'' function is expanded to
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``frame_register_unwind (get_next_frame (FRAME)'' and hence that
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call will expand to ``frame_register_unwind (get_next_frame
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(get_prev_frame (NEXT_FRAME)))''. Might as well call
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``frame_register_unwind (NEXT_FRAME)'' directly.
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THIS_PROLOGUE_CACHE can be used to share any prolog analysis data
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with the other unwind methods. Memory for that cache should be
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allocated using frame_obstack_zalloc(). */
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typedef void (frame_prev_register_ftype) (struct frame_info *next_frame,
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void **this_prologue_cache,
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int prev_regnum,
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int *optimized,
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enum lval_type * lvalp,
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CORE_ADDR *addrp,
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int *realnump, void *valuep);
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struct frame_unwind
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{
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/* Should the frame's type go here? */
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/* Should an attribute indicating the frame's address-in-block go
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here? */
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frame_this_id_ftype *this_id;
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frame_prev_register_ftype *prev_register;
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};
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#endif
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