12b0b6deed
and special_addr_p. (frame_id_build, frame_id_build_special): Update comments. (frame_id_build_wild): New prototype. * frame.c (frame_id_build, frame_id_build_special): Fill in new struct frame_id fields. (frame_id_build_wild): New function. (frame_id_eq, frame_id_inner): Use new struct frame_id fields.
2250 lines
75 KiB
C
2250 lines
75 KiB
C
/* Cache and manage frames for GDB, the GNU debugger.
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Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000,
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2001, 2002, 2003, 2004 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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#include "defs.h"
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#include "frame.h"
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#include "target.h"
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#include "value.h"
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#include "inferior.h" /* for inferior_ptid */
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#include "regcache.h"
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#include "gdb_assert.h"
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#include "gdb_string.h"
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#include "user-regs.h"
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#include "gdb_obstack.h"
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#include "dummy-frame.h"
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#include "sentinel-frame.h"
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#include "gdbcore.h"
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#include "annotate.h"
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#include "language.h"
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#include "frame-unwind.h"
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#include "frame-base.h"
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#include "command.h"
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#include "gdbcmd.h"
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#include "observer.h"
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static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame);
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/* We keep a cache of stack frames, each of which is a "struct
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frame_info". The innermost one gets allocated (in
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wait_for_inferior) each time the inferior stops; current_frame
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points to it. Additional frames get allocated (in get_prev_frame)
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as needed, and are chained through the next and prev fields. Any
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time that the frame cache becomes invalid (most notably when we
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execute something, but also if we change how we interpret the
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frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything
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which reads new symbols)), we should call reinit_frame_cache. */
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struct frame_info
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{
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/* Level of this frame. The inner-most (youngest) frame is at level
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0. As you move towards the outer-most (oldest) frame, the level
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increases. This is a cached value. It could just as easily be
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computed by counting back from the selected frame to the inner
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most frame. */
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/* NOTE: cagney/2002-04-05: Perhaps a level of ``-1'' should be
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reserved to indicate a bogus frame - one that has been created
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just to keep GDB happy (GDB always needs a frame). For the
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moment leave this as speculation. */
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int level;
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/* The frame's type. */
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/* FIXME: cagney/2004-05-01: Should instead just use ->unwind->type.
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Unfortunately, legacy_get_prev_frame is still explicitly setting
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the type. Eliminate that method and this field can be
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eliminated. */
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enum frame_type type;
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/* For each register, address of where it was saved on entry to the
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frame, or zero if it was not saved on entry to this frame. This
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includes special registers such as pc and fp saved in special
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ways in the stack frame. The SP_REGNUM is even more special, the
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address here is the sp for the previous frame, not the address
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where the sp was saved. */
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/* Allocated by frame_saved_regs_zalloc () which is called /
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initialized by DEPRECATED_FRAME_INIT_SAVED_REGS(). */
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CORE_ADDR *saved_regs; /*NUM_REGS + NUM_PSEUDO_REGS*/
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/* Anything extra for this structure that may have been defined in
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the machine dependent files. */
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/* Allocated by frame_extra_info_zalloc () which is called /
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initialized by DEPRECATED_INIT_EXTRA_FRAME_INFO */
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struct frame_extra_info *extra_info;
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/* The frame's low-level unwinder and corresponding cache. The
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low-level unwinder is responsible for unwinding register values
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for the previous frame. The low-level unwind methods are
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selected based on the presence, or otherwise, of register unwind
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information such as CFI. */
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void *prologue_cache;
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const struct frame_unwind *unwind;
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/* Cached copy of the previous frame's resume address. */
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struct {
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int p;
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CORE_ADDR value;
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} prev_pc;
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/* Cached copy of the previous frame's function address. */
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struct
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{
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CORE_ADDR addr;
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int p;
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} prev_func;
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/* This frame's ID. */
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struct
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{
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int p;
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struct frame_id value;
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} this_id;
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/* The frame's high-level base methods, and corresponding cache.
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The high level base methods are selected based on the frame's
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debug info. */
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const struct frame_base *base;
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void *base_cache;
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/* Pointers to the next (down, inner, younger) and previous (up,
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outer, older) frame_info's in the frame cache. */
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struct frame_info *next; /* down, inner, younger */
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int prev_p;
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struct frame_info *prev; /* up, outer, older */
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};
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/* Flag to control debugging. */
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static int frame_debug;
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/* Flag to indicate whether backtraces should stop at main et.al. */
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static int backtrace_past_main;
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static unsigned int backtrace_limit = UINT_MAX;
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void
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fprint_frame_id (struct ui_file *file, struct frame_id id)
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{
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fprintf_unfiltered (file, "{stack=0x%s,code=0x%s,special=0x%s}",
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paddr_nz (id.stack_addr),
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paddr_nz (id.code_addr),
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paddr_nz (id.special_addr));
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}
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static void
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fprint_frame_type (struct ui_file *file, enum frame_type type)
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{
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switch (type)
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{
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case UNKNOWN_FRAME:
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fprintf_unfiltered (file, "UNKNOWN_FRAME");
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return;
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case NORMAL_FRAME:
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fprintf_unfiltered (file, "NORMAL_FRAME");
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return;
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case DUMMY_FRAME:
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fprintf_unfiltered (file, "DUMMY_FRAME");
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return;
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case SIGTRAMP_FRAME:
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fprintf_unfiltered (file, "SIGTRAMP_FRAME");
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return;
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default:
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fprintf_unfiltered (file, "<unknown type>");
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return;
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};
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}
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static void
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fprint_frame (struct ui_file *file, struct frame_info *fi)
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{
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if (fi == NULL)
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{
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fprintf_unfiltered (file, "<NULL frame>");
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return;
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}
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fprintf_unfiltered (file, "{");
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fprintf_unfiltered (file, "level=%d", fi->level);
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fprintf_unfiltered (file, ",");
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fprintf_unfiltered (file, "type=");
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fprint_frame_type (file, fi->type);
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fprintf_unfiltered (file, ",");
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fprintf_unfiltered (file, "unwind=");
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if (fi->unwind != NULL)
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gdb_print_host_address (fi->unwind, file);
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else
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fprintf_unfiltered (file, "<unknown>");
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fprintf_unfiltered (file, ",");
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fprintf_unfiltered (file, "pc=");
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if (fi->next != NULL && fi->next->prev_pc.p)
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fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_pc.value));
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else
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fprintf_unfiltered (file, "<unknown>");
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fprintf_unfiltered (file, ",");
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fprintf_unfiltered (file, "id=");
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if (fi->this_id.p)
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fprint_frame_id (file, fi->this_id.value);
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else
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fprintf_unfiltered (file, "<unknown>");
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fprintf_unfiltered (file, ",");
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fprintf_unfiltered (file, "func=");
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if (fi->next != NULL && fi->next->prev_func.p)
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fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_func.addr));
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else
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fprintf_unfiltered (file, "<unknown>");
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fprintf_unfiltered (file, "}");
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}
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/* Return a frame uniq ID that can be used to, later, re-find the
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frame. */
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struct frame_id
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get_frame_id (struct frame_info *fi)
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{
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if (fi == NULL)
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{
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return null_frame_id;
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}
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if (!fi->this_id.p)
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{
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gdb_assert (!legacy_frame_p (current_gdbarch));
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if (frame_debug)
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fprintf_unfiltered (gdb_stdlog, "{ get_frame_id (fi=%d) ",
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fi->level);
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/* Find the unwinder. */
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if (fi->unwind == NULL)
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{
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fi->unwind = frame_unwind_find_by_frame (fi->next,
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&fi->prologue_cache);
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/* FIXME: cagney/2004-05-01: Should instead just use
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->unwind->type. Unfortunately, legacy_get_prev_frame is
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still explicitly setting the type. Eliminate that method
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and this field can be eliminated. */
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fi->type = fi->unwind->type;
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}
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/* Find THIS frame's ID. */
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fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->this_id.value);
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fi->this_id.p = 1;
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if (frame_debug)
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{
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fprintf_unfiltered (gdb_stdlog, "-> ");
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fprint_frame_id (gdb_stdlog, fi->this_id.value);
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fprintf_unfiltered (gdb_stdlog, " }\n");
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}
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}
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return fi->this_id.value;
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}
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struct frame_id
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frame_unwind_id (struct frame_info *next_frame)
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{
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/* Use prev_frame, and not get_prev_frame. The latter will truncate
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the frame chain, leading to this function unintentionally
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returning a null_frame_id (e.g., when a caller requests the frame
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ID of "main()"s caller. */
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return get_frame_id (get_prev_frame_1 (next_frame));
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}
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const struct frame_id null_frame_id; /* All zeros. */
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struct frame_id
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frame_id_build_special (CORE_ADDR stack_addr, CORE_ADDR code_addr,
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CORE_ADDR special_addr)
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{
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struct frame_id id = null_frame_id;
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id.stack_addr = stack_addr;
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id.stack_addr_p = 1;
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id.code_addr = code_addr;
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id.code_addr_p = 1;
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id.special_addr = special_addr;
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id.special_addr_p = 1;
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return id;
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}
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struct frame_id
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frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr)
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{
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struct frame_id id = null_frame_id;
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id.stack_addr = stack_addr;
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id.stack_addr_p = 1;
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id.code_addr = code_addr;
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id.code_addr_p = 1;
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return id;
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}
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struct frame_id
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frame_id_build_wild (CORE_ADDR stack_addr)
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{
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struct frame_id id = null_frame_id;
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id.stack_addr = stack_addr;
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id.stack_addr_p = 1;
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return id;
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}
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int
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frame_id_p (struct frame_id l)
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{
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int p;
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/* The frame is valid iff it has a valid stack address. */
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p = l.stack_addr_p;
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if (frame_debug)
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{
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fprintf_unfiltered (gdb_stdlog, "{ frame_id_p (l=");
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fprint_frame_id (gdb_stdlog, l);
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fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", p);
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}
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return p;
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}
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int
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frame_id_eq (struct frame_id l, struct frame_id r)
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{
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int eq;
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if (!l.stack_addr_p || !r.stack_addr_p)
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/* Like a NaN, if either ID is invalid, the result is false.
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Note that a frame ID is invalid iff it is the null frame ID. */
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eq = 0;
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else if (l.stack_addr != r.stack_addr)
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/* If .stack addresses are different, the frames are different. */
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eq = 0;
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else if (!l.code_addr_p || !r.code_addr_p)
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/* An invalid code addr is a wild card, always succeed. */
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eq = 1;
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else if (l.code_addr != r.code_addr)
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/* If .code addresses are different, the frames are different. */
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eq = 0;
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else if (!l.special_addr_p || !r.special_addr_p)
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/* An invalid special addr is a wild card (or unused), always succeed. */
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eq = 1;
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else if (l.special_addr == r.special_addr)
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/* Frames are equal. */
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eq = 1;
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else
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/* No luck. */
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eq = 0;
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if (frame_debug)
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{
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fprintf_unfiltered (gdb_stdlog, "{ frame_id_eq (l=");
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fprint_frame_id (gdb_stdlog, l);
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fprintf_unfiltered (gdb_stdlog, ",r=");
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fprint_frame_id (gdb_stdlog, r);
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fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", eq);
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}
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return eq;
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}
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int
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frame_id_inner (struct frame_id l, struct frame_id r)
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{
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int inner;
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if (!l.stack_addr_p || !r.stack_addr_p)
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/* Like NaN, any operation involving an invalid ID always fails. */
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inner = 0;
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else
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/* Only return non-zero when strictly inner than. Note that, per
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comment in "frame.h", there is some fuzz here. Frameless
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functions are not strictly inner than (same .stack but
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different .code and/or .special address). */
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inner = INNER_THAN (l.stack_addr, r.stack_addr);
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if (frame_debug)
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{
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fprintf_unfiltered (gdb_stdlog, "{ frame_id_inner (l=");
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fprint_frame_id (gdb_stdlog, l);
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fprintf_unfiltered (gdb_stdlog, ",r=");
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fprint_frame_id (gdb_stdlog, r);
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fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", inner);
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}
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return inner;
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}
|
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|
|
struct frame_info *
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frame_find_by_id (struct frame_id id)
|
|
{
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struct frame_info *frame;
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|
|
|
/* ZERO denotes the null frame, let the caller decide what to do
|
|
about it. Should it instead return get_current_frame()? */
|
|
if (!frame_id_p (id))
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return NULL;
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|
|
|
for (frame = get_current_frame ();
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|
frame != NULL;
|
|
frame = get_prev_frame (frame))
|
|
{
|
|
struct frame_id this = get_frame_id (frame);
|
|
if (frame_id_eq (id, this))
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|
/* An exact match. */
|
|
return frame;
|
|
if (frame_id_inner (id, this))
|
|
/* Gone to far. */
|
|
return NULL;
|
|
/* Either we're not yet gone far enough out along the frame
|
|
chain (inner(this,id)), or we're comparing frameless functions
|
|
(same .base, different .func, no test available). Struggle
|
|
on until we've definitly gone to far. */
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
CORE_ADDR
|
|
frame_pc_unwind (struct frame_info *this_frame)
|
|
{
|
|
if (!this_frame->prev_pc.p)
|
|
{
|
|
CORE_ADDR pc;
|
|
if (gdbarch_unwind_pc_p (current_gdbarch))
|
|
{
|
|
/* The right way. The `pure' way. The one true way. This
|
|
method depends solely on the register-unwind code to
|
|
determine the value of registers in THIS frame, and hence
|
|
the value of this frame's PC (resume address). A typical
|
|
implementation is no more than:
|
|
|
|
frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
|
|
return extract_unsigned_integer (buf, size of ISA_PC_REGNUM);
|
|
|
|
Note: this method is very heavily dependent on a correct
|
|
register-unwind implementation, it pays to fix that
|
|
method first; this method is frame type agnostic, since
|
|
it only deals with register values, it works with any
|
|
frame. This is all in stark contrast to the old
|
|
FRAME_SAVED_PC which would try to directly handle all the
|
|
different ways that a PC could be unwound. */
|
|
pc = gdbarch_unwind_pc (current_gdbarch, this_frame);
|
|
}
|
|
else if (this_frame->level < 0)
|
|
{
|
|
/* FIXME: cagney/2003-03-06: Old code and a sentinel
|
|
frame. Do like was always done. Fetch the PC's value
|
|
directly from the global registers array (via read_pc).
|
|
This assumes that this frame belongs to the current
|
|
global register cache. The assumption is dangerous. */
|
|
pc = read_pc ();
|
|
}
|
|
else if (DEPRECATED_FRAME_SAVED_PC_P ())
|
|
{
|
|
/* FIXME: cagney/2003-03-06: Old code, but not a sentinel
|
|
frame. Do like was always done. Note that this method,
|
|
unlike unwind_pc(), tries to handle all the different
|
|
frame cases directly. It fails. */
|
|
pc = DEPRECATED_FRAME_SAVED_PC (this_frame);
|
|
}
|
|
else
|
|
internal_error (__FILE__, __LINE__, "No gdbarch_unwind_pc method");
|
|
this_frame->prev_pc.value = pc;
|
|
this_frame->prev_pc.p = 1;
|
|
if (frame_debug)
|
|
fprintf_unfiltered (gdb_stdlog,
|
|
"{ frame_pc_unwind (this_frame=%d) -> 0x%s }\n",
|
|
this_frame->level,
|
|
paddr_nz (this_frame->prev_pc.value));
|
|
}
|
|
return this_frame->prev_pc.value;
|
|
}
|
|
|
|
CORE_ADDR
|
|
frame_func_unwind (struct frame_info *fi)
|
|
{
|
|
if (!fi->prev_func.p)
|
|
{
|
|
/* Make certain that this, and not the adjacent, function is
|
|
found. */
|
|
CORE_ADDR addr_in_block = frame_unwind_address_in_block (fi);
|
|
fi->prev_func.p = 1;
|
|
fi->prev_func.addr = get_pc_function_start (addr_in_block);
|
|
if (frame_debug)
|
|
fprintf_unfiltered (gdb_stdlog,
|
|
"{ frame_func_unwind (fi=%d) -> 0x%s }\n",
|
|
fi->level, paddr_nz (fi->prev_func.addr));
|
|
}
|
|
return fi->prev_func.addr;
|
|
}
|
|
|
|
CORE_ADDR
|
|
get_frame_func (struct frame_info *fi)
|
|
{
|
|
return frame_func_unwind (fi->next);
|
|
}
|
|
|
|
static int
|
|
do_frame_unwind_register (void *src, int regnum, void *buf)
|
|
{
|
|
frame_unwind_register (src, regnum, buf);
|
|
return 1;
|
|
}
|
|
|
|
void
|
|
frame_pop (struct frame_info *this_frame)
|
|
{
|
|
struct regcache *scratch_regcache;
|
|
struct cleanup *cleanups;
|
|
|
|
if (DEPRECATED_POP_FRAME_P ())
|
|
{
|
|
/* A legacy architecture that has implemented a custom pop
|
|
function. All new architectures should instead be using the
|
|
generic code below. */
|
|
DEPRECATED_POP_FRAME;
|
|
}
|
|
else
|
|
{
|
|
/* Make a copy of all the register values unwound from this
|
|
frame. Save them in a scratch buffer so that there isn't a
|
|
race between trying to extract the old values from the
|
|
current_regcache while at the same time writing new values
|
|
into that same cache. */
|
|
struct regcache *scratch = regcache_xmalloc (current_gdbarch);
|
|
struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch);
|
|
regcache_save (scratch, do_frame_unwind_register, this_frame);
|
|
/* FIXME: cagney/2003-03-16: It should be possible to tell the
|
|
target's register cache that it is about to be hit with a
|
|
burst register transfer and that the sequence of register
|
|
writes should be batched. The pair target_prepare_to_store()
|
|
and target_store_registers() kind of suggest this
|
|
functionality. Unfortunately, they don't implement it. Their
|
|
lack of a formal definition can lead to targets writing back
|
|
bogus values (arguably a bug in the target code mind). */
|
|
/* Now copy those saved registers into the current regcache.
|
|
Here, regcache_cpy() calls regcache_restore(). */
|
|
regcache_cpy (current_regcache, scratch);
|
|
do_cleanups (cleanups);
|
|
}
|
|
/* We've made right mess of GDB's local state, just discard
|
|
everything. */
|
|
flush_cached_frames ();
|
|
}
|
|
|
|
void
|
|
frame_register_unwind (struct frame_info *frame, int regnum,
|
|
int *optimizedp, enum lval_type *lvalp,
|
|
CORE_ADDR *addrp, int *realnump, void *bufferp)
|
|
{
|
|
struct frame_unwind_cache *cache;
|
|
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "\
|
|
{ frame_register_unwind (frame=%d,regnum=%d(%s),...) ",
|
|
frame->level, regnum,
|
|
frame_map_regnum_to_name (frame, regnum));
|
|
}
|
|
|
|
/* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
|
|
that the value proper does not need to be fetched. */
|
|
gdb_assert (optimizedp != NULL);
|
|
gdb_assert (lvalp != NULL);
|
|
gdb_assert (addrp != NULL);
|
|
gdb_assert (realnump != NULL);
|
|
/* gdb_assert (bufferp != NULL); */
|
|
|
|
/* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame
|
|
is broken. There is always a frame. If there, for some reason,
|
|
isn't a frame, there is some pretty busted code as it should have
|
|
detected the problem before calling here. */
|
|
gdb_assert (frame != NULL);
|
|
|
|
/* Find the unwinder. */
|
|
if (frame->unwind == NULL)
|
|
{
|
|
frame->unwind = frame_unwind_find_by_frame (frame->next,
|
|
&frame->prologue_cache);
|
|
/* FIXME: cagney/2004-05-01: Should instead just use ->unwind->type.
|
|
Unfortunately, legacy_get_prev_frame is still explicitly setting
|
|
the type. Eliminate that method and this field can be
|
|
eliminated. */
|
|
frame->type = frame->unwind->type;
|
|
}
|
|
|
|
/* Ask this frame to unwind its register. See comment in
|
|
"frame-unwind.h" for why NEXT frame and this unwind cache are
|
|
passed in. */
|
|
frame->unwind->prev_register (frame->next, &frame->prologue_cache, regnum,
|
|
optimizedp, lvalp, addrp, realnump, bufferp);
|
|
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "->");
|
|
fprintf_unfiltered (gdb_stdlog, " *optimizedp=%d", (*optimizedp));
|
|
fprintf_unfiltered (gdb_stdlog, " *lvalp=%d", (int) (*lvalp));
|
|
fprintf_unfiltered (gdb_stdlog, " *addrp=0x%s", paddr_nz ((*addrp)));
|
|
fprintf_unfiltered (gdb_stdlog, " *bufferp=");
|
|
if (bufferp == NULL)
|
|
fprintf_unfiltered (gdb_stdlog, "<NULL>");
|
|
else
|
|
{
|
|
int i;
|
|
const unsigned char *buf = bufferp;
|
|
fprintf_unfiltered (gdb_stdlog, "[");
|
|
for (i = 0; i < register_size (current_gdbarch, regnum); i++)
|
|
fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
|
|
fprintf_unfiltered (gdb_stdlog, "]");
|
|
}
|
|
fprintf_unfiltered (gdb_stdlog, " }\n");
|
|
}
|
|
}
|
|
|
|
void
|
|
frame_register (struct frame_info *frame, int regnum,
|
|
int *optimizedp, enum lval_type *lvalp,
|
|
CORE_ADDR *addrp, int *realnump, void *bufferp)
|
|
{
|
|
/* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
|
|
that the value proper does not need to be fetched. */
|
|
gdb_assert (optimizedp != NULL);
|
|
gdb_assert (lvalp != NULL);
|
|
gdb_assert (addrp != NULL);
|
|
gdb_assert (realnump != NULL);
|
|
/* gdb_assert (bufferp != NULL); */
|
|
|
|
/* Ulgh! Old code that, for lval_register, sets ADDRP to the offset
|
|
of the register in the register cache. It should instead return
|
|
the REGNUM corresponding to that register. Translate the . */
|
|
if (DEPRECATED_GET_SAVED_REGISTER_P ())
|
|
{
|
|
DEPRECATED_GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame,
|
|
regnum, lvalp);
|
|
/* Compute the REALNUM if the caller wants it. */
|
|
if (*lvalp == lval_register)
|
|
{
|
|
int regnum;
|
|
for (regnum = 0; regnum < NUM_REGS + NUM_PSEUDO_REGS; regnum++)
|
|
{
|
|
if (*addrp == register_offset_hack (current_gdbarch, regnum))
|
|
{
|
|
*realnump = regnum;
|
|
return;
|
|
}
|
|
}
|
|
internal_error (__FILE__, __LINE__,
|
|
"Failed to compute the register number corresponding"
|
|
" to 0x%s", paddr_d (*addrp));
|
|
}
|
|
*realnump = -1;
|
|
return;
|
|
}
|
|
|
|
/* Obtain the register value by unwinding the register from the next
|
|
(more inner frame). */
|
|
gdb_assert (frame != NULL && frame->next != NULL);
|
|
frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
|
|
realnump, bufferp);
|
|
}
|
|
|
|
void
|
|
frame_unwind_register (struct frame_info *frame, int regnum, void *buf)
|
|
{
|
|
int optimized;
|
|
CORE_ADDR addr;
|
|
int realnum;
|
|
enum lval_type lval;
|
|
frame_register_unwind (frame, regnum, &optimized, &lval, &addr,
|
|
&realnum, buf);
|
|
}
|
|
|
|
void
|
|
get_frame_register (struct frame_info *frame,
|
|
int regnum, void *buf)
|
|
{
|
|
frame_unwind_register (frame->next, regnum, buf);
|
|
}
|
|
|
|
LONGEST
|
|
frame_unwind_register_signed (struct frame_info *frame, int regnum)
|
|
{
|
|
char buf[MAX_REGISTER_SIZE];
|
|
frame_unwind_register (frame, regnum, buf);
|
|
return extract_signed_integer (buf, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum));
|
|
}
|
|
|
|
LONGEST
|
|
get_frame_register_signed (struct frame_info *frame, int regnum)
|
|
{
|
|
return frame_unwind_register_signed (frame->next, regnum);
|
|
}
|
|
|
|
ULONGEST
|
|
frame_unwind_register_unsigned (struct frame_info *frame, int regnum)
|
|
{
|
|
char buf[MAX_REGISTER_SIZE];
|
|
frame_unwind_register (frame, regnum, buf);
|
|
return extract_unsigned_integer (buf, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum));
|
|
}
|
|
|
|
ULONGEST
|
|
get_frame_register_unsigned (struct frame_info *frame, int regnum)
|
|
{
|
|
return frame_unwind_register_unsigned (frame->next, regnum);
|
|
}
|
|
|
|
void
|
|
frame_unwind_unsigned_register (struct frame_info *frame, int regnum,
|
|
ULONGEST *val)
|
|
{
|
|
char buf[MAX_REGISTER_SIZE];
|
|
frame_unwind_register (frame, regnum, buf);
|
|
(*val) = extract_unsigned_integer (buf, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum));
|
|
}
|
|
|
|
void
|
|
put_frame_register (struct frame_info *frame, int regnum, const void *buf)
|
|
{
|
|
struct gdbarch *gdbarch = get_frame_arch (frame);
|
|
int realnum;
|
|
int optim;
|
|
enum lval_type lval;
|
|
CORE_ADDR addr;
|
|
frame_register (frame, regnum, &optim, &lval, &addr, &realnum, NULL);
|
|
if (optim)
|
|
error ("Attempt to assign to a value that was optimized out.");
|
|
switch (lval)
|
|
{
|
|
case lval_memory:
|
|
{
|
|
/* FIXME: write_memory doesn't yet take constant buffers.
|
|
Arrrg! */
|
|
char tmp[MAX_REGISTER_SIZE];
|
|
memcpy (tmp, buf, register_size (gdbarch, regnum));
|
|
write_memory (addr, tmp, register_size (gdbarch, regnum));
|
|
break;
|
|
}
|
|
case lval_register:
|
|
regcache_cooked_write (current_regcache, realnum, buf);
|
|
break;
|
|
default:
|
|
error ("Attempt to assign to an unmodifiable value.");
|
|
}
|
|
}
|
|
|
|
/* frame_register_read ()
|
|
|
|
Find and return the value of REGNUM for the specified stack frame.
|
|
The number of bytes copied is DEPRECATED_REGISTER_RAW_SIZE
|
|
(REGNUM).
|
|
|
|
Returns 0 if the register value could not be found. */
|
|
|
|
int
|
|
frame_register_read (struct frame_info *frame, int regnum, void *myaddr)
|
|
{
|
|
int optimized;
|
|
enum lval_type lval;
|
|
CORE_ADDR addr;
|
|
int realnum;
|
|
frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr);
|
|
|
|
/* FIXME: cagney/2002-05-15: This test is just bogus.
|
|
|
|
It indicates that the target failed to supply a value for a
|
|
register because it was "not available" at this time. Problem
|
|
is, the target still has the register and so get saved_register()
|
|
may be returning a value saved on the stack. */
|
|
|
|
if (register_cached (regnum) < 0)
|
|
return 0; /* register value not available */
|
|
|
|
return !optimized;
|
|
}
|
|
|
|
|
|
/* Map between a frame register number and its name. A frame register
|
|
space is a superset of the cooked register space --- it also
|
|
includes builtin registers. */
|
|
|
|
int
|
|
frame_map_name_to_regnum (struct frame_info *frame, const char *name, int len)
|
|
{
|
|
return user_reg_map_name_to_regnum (get_frame_arch (frame), name, len);
|
|
}
|
|
|
|
const char *
|
|
frame_map_regnum_to_name (struct frame_info *frame, int regnum)
|
|
{
|
|
return user_reg_map_regnum_to_name (get_frame_arch (frame), regnum);
|
|
}
|
|
|
|
/* Create a sentinel frame. */
|
|
|
|
static struct frame_info *
|
|
create_sentinel_frame (struct regcache *regcache)
|
|
{
|
|
struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
|
|
frame->type = SENTINEL_FRAME;
|
|
frame->level = -1;
|
|
/* Explicitly initialize the sentinel frame's cache. Provide it
|
|
with the underlying regcache. In the future additional
|
|
information, such as the frame's thread will be added. */
|
|
frame->prologue_cache = sentinel_frame_cache (regcache);
|
|
/* For the moment there is only one sentinel frame implementation. */
|
|
frame->unwind = sentinel_frame_unwind;
|
|
/* Link this frame back to itself. The frame is self referential
|
|
(the unwound PC is the same as the pc), so make it so. */
|
|
frame->next = frame;
|
|
/* Make the sentinel frame's ID valid, but invalid. That way all
|
|
comparisons with it should fail. */
|
|
frame->this_id.p = 1;
|
|
frame->this_id.value = null_frame_id;
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "{ create_sentinel_frame (...) -> ");
|
|
fprint_frame (gdb_stdlog, frame);
|
|
fprintf_unfiltered (gdb_stdlog, " }\n");
|
|
}
|
|
return frame;
|
|
}
|
|
|
|
/* Info about the innermost stack frame (contents of FP register) */
|
|
|
|
static struct frame_info *current_frame;
|
|
|
|
/* Cache for frame addresses already read by gdb. Valid only while
|
|
inferior is stopped. Control variables for the frame cache should
|
|
be local to this module. */
|
|
|
|
static struct obstack frame_cache_obstack;
|
|
|
|
void *
|
|
frame_obstack_zalloc (unsigned long size)
|
|
{
|
|
void *data = obstack_alloc (&frame_cache_obstack, size);
|
|
memset (data, 0, size);
|
|
return data;
|
|
}
|
|
|
|
CORE_ADDR *
|
|
frame_saved_regs_zalloc (struct frame_info *fi)
|
|
{
|
|
fi->saved_regs = (CORE_ADDR *)
|
|
frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS);
|
|
return fi->saved_regs;
|
|
}
|
|
|
|
CORE_ADDR *
|
|
deprecated_get_frame_saved_regs (struct frame_info *fi)
|
|
{
|
|
return fi->saved_regs;
|
|
}
|
|
|
|
/* Return the innermost (currently executing) stack frame. This is
|
|
split into two functions. The function unwind_to_current_frame()
|
|
is wrapped in catch exceptions so that, even when the unwind of the
|
|
sentinel frame fails, the function still returns a stack frame. */
|
|
|
|
static int
|
|
unwind_to_current_frame (struct ui_out *ui_out, void *args)
|
|
{
|
|
struct frame_info *frame = get_prev_frame (args);
|
|
/* A sentinel frame can fail to unwind, e.g., because its PC value
|
|
lands in somewhere like start. */
|
|
if (frame == NULL)
|
|
return 1;
|
|
current_frame = frame;
|
|
return 0;
|
|
}
|
|
|
|
struct frame_info *
|
|
get_current_frame (void)
|
|
{
|
|
/* First check, and report, the lack of registers. Having GDB
|
|
report "No stack!" or "No memory" when the target doesn't even
|
|
have registers is very confusing. Besides, "printcmd.exp"
|
|
explicitly checks that ``print $pc'' with no registers prints "No
|
|
registers". */
|
|
if (!target_has_registers)
|
|
error ("No registers.");
|
|
if (!target_has_stack)
|
|
error ("No stack.");
|
|
if (!target_has_memory)
|
|
error ("No memory.");
|
|
if (current_frame == NULL)
|
|
{
|
|
struct frame_info *sentinel_frame =
|
|
create_sentinel_frame (current_regcache);
|
|
if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame,
|
|
NULL, RETURN_MASK_ERROR) != 0)
|
|
{
|
|
/* Oops! Fake a current frame? Is this useful? It has a PC
|
|
of zero, for instance. */
|
|
current_frame = sentinel_frame;
|
|
}
|
|
}
|
|
return current_frame;
|
|
}
|
|
|
|
/* The "selected" stack frame is used by default for local and arg
|
|
access. May be zero, for no selected frame. */
|
|
|
|
struct frame_info *deprecated_selected_frame;
|
|
|
|
/* Return the selected frame. Always non-NULL (unless there isn't an
|
|
inferior sufficient for creating a frame) in which case an error is
|
|
thrown. */
|
|
|
|
struct frame_info *
|
|
get_selected_frame (void)
|
|
{
|
|
if (deprecated_selected_frame == NULL)
|
|
/* Hey! Don't trust this. It should really be re-finding the
|
|
last selected frame of the currently selected thread. This,
|
|
though, is better than nothing. */
|
|
select_frame (get_current_frame ());
|
|
/* There is always a frame. */
|
|
gdb_assert (deprecated_selected_frame != NULL);
|
|
return deprecated_selected_frame;
|
|
}
|
|
|
|
/* This is a variant of get_selected_frame() which can be called when
|
|
the inferior does not have a frame; in that case it will return
|
|
NULL instead of calling error(). */
|
|
|
|
struct frame_info *
|
|
deprecated_safe_get_selected_frame (void)
|
|
{
|
|
if (!target_has_registers || !target_has_stack || !target_has_memory)
|
|
return NULL;
|
|
return get_selected_frame ();
|
|
}
|
|
|
|
/* Select frame FI (or NULL - to invalidate the current frame). */
|
|
|
|
void
|
|
select_frame (struct frame_info *fi)
|
|
{
|
|
struct symtab *s;
|
|
|
|
deprecated_selected_frame = fi;
|
|
/* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the
|
|
frame is being invalidated. */
|
|
if (deprecated_selected_frame_level_changed_hook)
|
|
deprecated_selected_frame_level_changed_hook (frame_relative_level (fi));
|
|
|
|
/* FIXME: kseitz/2002-08-28: It would be nice to call
|
|
selected_frame_level_changed_event() right here, but due to limitations
|
|
in the current interfaces, we would end up flooding UIs with events
|
|
because select_frame() is used extensively internally.
|
|
|
|
Once we have frame-parameterized frame (and frame-related) commands,
|
|
the event notification can be moved here, since this function will only
|
|
be called when the user's selected frame is being changed. */
|
|
|
|
/* Ensure that symbols for this frame are read in. Also, determine the
|
|
source language of this frame, and switch to it if desired. */
|
|
if (fi)
|
|
{
|
|
/* We retrieve the frame's symtab by using the frame PC. However
|
|
we cannot use the frame PC as-is, because it usually points to
|
|
the instruction following the "call", which is sometimes the
|
|
first instruction of another function. So we rely on
|
|
get_frame_address_in_block() which provides us with a PC which
|
|
is guaranteed to be inside the frame's code block. */
|
|
s = find_pc_symtab (get_frame_address_in_block (fi));
|
|
if (s
|
|
&& s->language != current_language->la_language
|
|
&& s->language != language_unknown
|
|
&& language_mode == language_mode_auto)
|
|
{
|
|
set_language (s->language);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Return the register saved in the simplistic ``saved_regs'' cache.
|
|
If the value isn't here AND a value is needed, try the next inner
|
|
most frame. */
|
|
|
|
static void
|
|
legacy_saved_regs_prev_register (struct frame_info *next_frame,
|
|
void **this_prologue_cache,
|
|
int regnum, int *optimizedp,
|
|
enum lval_type *lvalp, CORE_ADDR *addrp,
|
|
int *realnump, void *bufferp)
|
|
{
|
|
/* HACK: New code is passed the next frame and this cache.
|
|
Unfortunately, old code expects this frame. Since this is a
|
|
backward compatibility hack, cheat by walking one level along the
|
|
prologue chain to the frame the old code expects.
|
|
|
|
Do not try this at home. Professional driver, closed course. */
|
|
struct frame_info *frame = next_frame->prev;
|
|
gdb_assert (frame != NULL);
|
|
|
|
if (deprecated_get_frame_saved_regs (frame) == NULL)
|
|
{
|
|
/* If nothing has initialized the saved regs, do it now. */
|
|
gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
|
|
DEPRECATED_FRAME_INIT_SAVED_REGS (frame);
|
|
gdb_assert (deprecated_get_frame_saved_regs (frame) != NULL);
|
|
}
|
|
|
|
if (deprecated_get_frame_saved_regs (frame) != NULL
|
|
&& deprecated_get_frame_saved_regs (frame)[regnum] != 0)
|
|
{
|
|
if (regnum == SP_REGNUM)
|
|
{
|
|
/* SP register treated specially. */
|
|
*optimizedp = 0;
|
|
*lvalp = not_lval;
|
|
*addrp = 0;
|
|
*realnump = -1;
|
|
if (bufferp != NULL)
|
|
/* NOTE: cagney/2003-05-09: In-lined store_address() with
|
|
it's body - store_unsigned_integer(). */
|
|
store_unsigned_integer (bufferp, DEPRECATED_REGISTER_RAW_SIZE (regnum),
|
|
deprecated_get_frame_saved_regs (frame)[regnum]);
|
|
}
|
|
else
|
|
{
|
|
/* Any other register is saved in memory, fetch it but cache
|
|
a local copy of its value. */
|
|
*optimizedp = 0;
|
|
*lvalp = lval_memory;
|
|
*addrp = deprecated_get_frame_saved_regs (frame)[regnum];
|
|
*realnump = -1;
|
|
if (bufferp != NULL)
|
|
{
|
|
#if 1
|
|
/* Save each register value, as it is read in, in a
|
|
frame based cache. */
|
|
void **regs = (*this_prologue_cache);
|
|
if (regs == NULL)
|
|
{
|
|
int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS)
|
|
* sizeof (void *));
|
|
regs = frame_obstack_zalloc (sizeof_cache);
|
|
(*this_prologue_cache) = regs;
|
|
}
|
|
if (regs[regnum] == NULL)
|
|
{
|
|
regs[regnum]
|
|
= frame_obstack_zalloc (DEPRECATED_REGISTER_RAW_SIZE (regnum));
|
|
read_memory (deprecated_get_frame_saved_regs (frame)[regnum], regs[regnum],
|
|
DEPRECATED_REGISTER_RAW_SIZE (regnum));
|
|
}
|
|
memcpy (bufferp, regs[regnum], DEPRECATED_REGISTER_RAW_SIZE (regnum));
|
|
#else
|
|
/* Read the value in from memory. */
|
|
read_memory (deprecated_get_frame_saved_regs (frame)[regnum], bufferp,
|
|
DEPRECATED_REGISTER_RAW_SIZE (regnum));
|
|
#endif
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* No luck. Assume this and the next frame have the same register
|
|
value. Pass the unwind request down the frame chain to the next
|
|
frame. Hopefully that frame will find the register's location. */
|
|
frame_register_unwind (next_frame, regnum, optimizedp, lvalp, addrp,
|
|
realnump, bufferp);
|
|
}
|
|
|
|
static void
|
|
legacy_saved_regs_this_id (struct frame_info *next_frame,
|
|
void **this_prologue_cache,
|
|
struct frame_id *id)
|
|
{
|
|
/* A developer is trying to bring up a new architecture, help them
|
|
by providing a default unwinder that refuses to unwind anything
|
|
(the ID is always NULL). In the case of legacy code,
|
|
legacy_get_prev_frame() will have previously set ->this_id.p, so
|
|
this code won't be called. */
|
|
(*id) = null_frame_id;
|
|
}
|
|
|
|
const struct frame_unwind legacy_saved_regs_unwinder = {
|
|
/* Not really. It gets overridden by legacy_get_prev_frame(). */
|
|
UNKNOWN_FRAME,
|
|
legacy_saved_regs_this_id,
|
|
legacy_saved_regs_prev_register
|
|
};
|
|
const struct frame_unwind *legacy_saved_regs_unwind = &legacy_saved_regs_unwinder;
|
|
|
|
/* Determine the frame's type based on its PC. */
|
|
|
|
static enum frame_type
|
|
frame_type_from_pc (CORE_ADDR pc)
|
|
{
|
|
/* NOTE: cagney/2004-05-08: Eliminating this function depends on all
|
|
architectures being forced to use the frame-unwind code. */
|
|
if (deprecated_pc_in_call_dummy (pc))
|
|
return DUMMY_FRAME;
|
|
else
|
|
return NORMAL_FRAME;
|
|
}
|
|
|
|
/* Create an arbitrary (i.e. address specified by user) or innermost frame.
|
|
Always returns a non-NULL value. */
|
|
|
|
struct frame_info *
|
|
create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
|
|
{
|
|
struct frame_info *fi;
|
|
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog,
|
|
"{ create_new_frame (addr=0x%s, pc=0x%s) ",
|
|
paddr_nz (addr), paddr_nz (pc));
|
|
}
|
|
|
|
fi = frame_obstack_zalloc (sizeof (struct frame_info));
|
|
|
|
fi->next = create_sentinel_frame (current_regcache);
|
|
|
|
/* Select/initialize both the unwind function and the frame's type
|
|
based on the PC. */
|
|
fi->unwind = frame_unwind_find_by_frame (fi->next, &fi->prologue_cache);
|
|
if (fi->unwind->type != UNKNOWN_FRAME)
|
|
fi->type = fi->unwind->type;
|
|
else
|
|
fi->type = frame_type_from_pc (pc);
|
|
|
|
fi->this_id.p = 1;
|
|
deprecated_update_frame_base_hack (fi, addr);
|
|
deprecated_update_frame_pc_hack (fi, pc);
|
|
|
|
if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
|
|
DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi);
|
|
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, fi);
|
|
fprintf_unfiltered (gdb_stdlog, " }\n");
|
|
}
|
|
|
|
return fi;
|
|
}
|
|
|
|
/* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
|
|
innermost frame). Be careful to not fall off the bottom of the
|
|
frame chain and onto the sentinel frame. */
|
|
|
|
struct frame_info *
|
|
get_next_frame (struct frame_info *this_frame)
|
|
{
|
|
if (this_frame->level > 0)
|
|
return this_frame->next;
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
/* Observer for the target_changed event. */
|
|
|
|
void
|
|
frame_observer_target_changed (struct target_ops *target)
|
|
{
|
|
flush_cached_frames ();
|
|
}
|
|
|
|
/* Flush the entire frame cache. */
|
|
|
|
void
|
|
flush_cached_frames (void)
|
|
{
|
|
/* Since we can't really be sure what the first object allocated was */
|
|
obstack_free (&frame_cache_obstack, 0);
|
|
obstack_init (&frame_cache_obstack);
|
|
|
|
current_frame = NULL; /* Invalidate cache */
|
|
select_frame (NULL);
|
|
annotate_frames_invalid ();
|
|
if (frame_debug)
|
|
fprintf_unfiltered (gdb_stdlog, "{ flush_cached_frames () }\n");
|
|
}
|
|
|
|
/* Flush the frame cache, and start a new one if necessary. */
|
|
|
|
void
|
|
reinit_frame_cache (void)
|
|
{
|
|
flush_cached_frames ();
|
|
|
|
/* FIXME: The inferior_ptid test is wrong if there is a corefile. */
|
|
if (PIDGET (inferior_ptid) != 0)
|
|
{
|
|
select_frame (get_current_frame ());
|
|
}
|
|
}
|
|
|
|
/* Create the previous frame using the deprecated methods
|
|
INIT_EXTRA_INFO, and INIT_FRAME_PC. */
|
|
|
|
static struct frame_info *
|
|
legacy_get_prev_frame (struct frame_info *this_frame)
|
|
{
|
|
CORE_ADDR address = 0;
|
|
struct frame_info *prev;
|
|
int fromleaf;
|
|
|
|
/* Don't frame_debug print legacy_get_prev_frame() here, just
|
|
confuses the output. */
|
|
|
|
/* Allocate the new frame.
|
|
|
|
There is no reason to worry about memory leaks, should the
|
|
remainder of the function fail. The allocated memory will be
|
|
quickly reclaimed when the frame cache is flushed, and the `we've
|
|
been here before' check, in get_prev_frame() will stop repeated
|
|
memory allocation calls. */
|
|
prev = FRAME_OBSTACK_ZALLOC (struct frame_info);
|
|
prev->level = this_frame->level + 1;
|
|
|
|
/* Do not completely wire it in to the frame chain. Some (bad) code
|
|
in INIT_FRAME_EXTRA_INFO tries to look along frame->prev to pull
|
|
some fancy tricks (of course such code is, by definition,
|
|
recursive).
|
|
|
|
On the other hand, methods, such as get_frame_pc() and
|
|
get_frame_base() rely on being able to walk along the frame
|
|
chain. Make certain that at least they work by providing that
|
|
link. Of course things manipulating prev can't go back. */
|
|
prev->next = this_frame;
|
|
|
|
/* NOTE: cagney/2002-11-18: Should have been correctly setting the
|
|
frame's type here, before anything else, and not last, at the
|
|
bottom of this function. The various
|
|
DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC, and
|
|
DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds
|
|
that handle the frame not being correctly set from the start.
|
|
Unfortunately those same work-arounds rely on the type defaulting
|
|
to NORMAL_FRAME. Ulgh! The new frame code does not have this
|
|
problem. */
|
|
prev->type = UNKNOWN_FRAME;
|
|
|
|
/* A legacy frame's ID is always computed here. Mark it as valid. */
|
|
prev->this_id.p = 1;
|
|
|
|
/* Handle sentinel frame unwind as a special case. */
|
|
if (this_frame->level < 0)
|
|
{
|
|
/* 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, DEPRECATED_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. */
|
|
|
|
deprecated_update_frame_pc_hack (prev, frame_pc_unwind (this_frame));
|
|
if (get_frame_pc (prev) == 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 legacy PC zero }\n");
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Set the unwind functions based on that identified PC. Ditto
|
|
for the "type" but strongly prefer the unwinder's frame type. */
|
|
prev->unwind = frame_unwind_find_by_frame (prev->next,
|
|
&prev->prologue_cache);
|
|
if (prev->unwind->type == UNKNOWN_FRAME)
|
|
prev->type = frame_type_from_pc (get_frame_pc (prev));
|
|
else
|
|
prev->type = prev->unwind->type;
|
|
|
|
/* Find the prev's frame's ID. */
|
|
if (prev->type == DUMMY_FRAME
|
|
&& gdbarch_unwind_dummy_id_p (current_gdbarch))
|
|
{
|
|
/* When unwinding a normal frame, the stack structure is
|
|
determined by analyzing the frame's function's code (be
|
|
it using brute force prologue analysis, or the dwarf2
|
|
CFI). In the case of a dummy frame, that simply isn't
|
|
possible. The The PC is either the program entry point,
|
|
or some random address on the stack. Trying to use that
|
|
PC to apply standard frame ID unwind techniques is just
|
|
asking for trouble. */
|
|
/* Use an architecture specific method to extract the prev's
|
|
dummy ID from the next frame. Note that this method uses
|
|
frame_register_unwind to obtain the register values
|
|
needed to determine the dummy frame's ID. */
|
|
prev->this_id.value = gdbarch_unwind_dummy_id (current_gdbarch,
|
|
this_frame);
|
|
}
|
|
else
|
|
{
|
|
/* We're unwinding a sentinel frame, the PC of which is
|
|
pointing at a stack dummy. Fake up the dummy frame's ID
|
|
using the same sequence as is found a traditional
|
|
unwinder. Once all architectures supply the
|
|
unwind_dummy_id method, this code can go away. */
|
|
prev->this_id.value = frame_id_build (deprecated_read_fp (),
|
|
read_pc ());
|
|
}
|
|
|
|
/* Check that the unwound ID is valid. */
|
|
if (!frame_id_p (prev->this_id.value))
|
|
{
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, NULL);
|
|
fprintf_unfiltered (gdb_stdlog,
|
|
" // unwound legacy 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 `sentinel'. Leave it until
|
|
after the switch to storing the frame ID, instead of the
|
|
frame base, in the frame object. */
|
|
|
|
/* Link it in. */
|
|
this_frame->prev = prev;
|
|
|
|
/* FIXME: cagney/2002-01-19: This call will go away. Instead of
|
|
initializing extra info, all frames will use the frame_cache
|
|
(passed to the unwind functions) to store additional frame
|
|
info. Unfortunately legacy targets can't use
|
|
legacy_get_prev_frame() to unwind the sentinel frame and,
|
|
consequently, are forced to take this code path and rely on
|
|
the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to
|
|
initialize the inner-most frame. */
|
|
if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
|
|
{
|
|
DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev);
|
|
}
|
|
|
|
if (prev->type == NORMAL_FRAME)
|
|
prev->this_id.value.code_addr
|
|
= get_pc_function_start (prev->this_id.value.code_addr);
|
|
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, prev);
|
|
fprintf_unfiltered (gdb_stdlog, " } // legacy innermost frame\n");
|
|
}
|
|
return prev;
|
|
}
|
|
|
|
/* This code only works on normal frames. A sentinel frame, where
|
|
the level is -1, should never reach this code. */
|
|
gdb_assert (this_frame->level >= 0);
|
|
|
|
/* On some machines it is possible to call a function without
|
|
setting up a stack frame for it. On these machines, we
|
|
define this macro to take two args; a frameinfo pointer
|
|
identifying a frame and a variable to set or clear if it is
|
|
or isn't leafless. */
|
|
|
|
/* Still don't want to worry about this except on the innermost
|
|
frame. This macro will set FROMLEAF if THIS_FRAME is a frameless
|
|
function invocation. */
|
|
if (this_frame->level == 0)
|
|
/* FIXME: 2002-11-09: Frameless functions can occur anywhere in
|
|
the frame chain, not just the inner most frame! The generic,
|
|
per-architecture, frame code should handle this and the below
|
|
should simply be removed. */
|
|
fromleaf = (DEPRECATED_FRAMELESS_FUNCTION_INVOCATION_P ()
|
|
&& DEPRECATED_FRAMELESS_FUNCTION_INVOCATION (this_frame));
|
|
else
|
|
fromleaf = 0;
|
|
|
|
if (fromleaf)
|
|
/* A frameless inner-most frame. The `FP' (which isn't an
|
|
architecture frame-pointer register!) of the caller is the same
|
|
as the callee. */
|
|
/* FIXME: 2002-11-09: There isn't any reason to special case this
|
|
edge condition. Instead the per-architecture code should handle
|
|
it locally. */
|
|
/* FIXME: cagney/2003-06-16: This returns the inner most stack
|
|
address for the previous frame, that, however, is wrong. It
|
|
should be the inner most stack address for the previous to
|
|
previous frame. This is because it is the previous to previous
|
|
frame's innermost stack address that is constant through out
|
|
the lifetime of the previous frame (trust me :-). */
|
|
address = get_frame_base (this_frame);
|
|
else
|
|
{
|
|
/* Two macros defined in tm.h specify the machine-dependent
|
|
actions to be performed here.
|
|
|
|
First, get the frame's chain-pointer.
|
|
|
|
If that is zero, the frame is the outermost frame or a leaf
|
|
called by the outermost frame. This means that if start
|
|
calls main without a frame, we'll return 0 (which is fine
|
|
anyway).
|
|
|
|
Nope; there's a problem. This also returns when the current
|
|
routine is a leaf of main. This is unacceptable. We move
|
|
this to after the ffi test; I'd rather have backtraces from
|
|
start go curfluy than have an abort called from main not show
|
|
main. */
|
|
if (DEPRECATED_FRAME_CHAIN_P ())
|
|
address = DEPRECATED_FRAME_CHAIN (this_frame);
|
|
else
|
|
{
|
|
/* Someone is part way through coverting an old architecture
|
|
to the new frame code. Implement FRAME_CHAIN the way the
|
|
new frame will. */
|
|
/* Find PREV frame's unwinder. */
|
|
prev->unwind = frame_unwind_find_by_frame (this_frame,
|
|
&prev->prologue_cache);
|
|
/* FIXME: cagney/2004-05-01: Should instead just use
|
|
->unwind->type. Unfortunately, legacy_get_prev_frame is
|
|
still explicitly setting the type. Eliminate that method
|
|
and this field can be eliminated. */
|
|
prev->type = prev->unwind->type;
|
|
/* Find PREV frame's ID. */
|
|
prev->unwind->this_id (this_frame,
|
|
&prev->prologue_cache,
|
|
&prev->this_id.value);
|
|
prev->this_id.p = 1;
|
|
address = prev->this_id.value.stack_addr;
|
|
}
|
|
|
|
if (!legacy_frame_chain_valid (address, this_frame))
|
|
{
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, NULL);
|
|
fprintf_unfiltered (gdb_stdlog,
|
|
" // legacy frame chain invalid }\n");
|
|
}
|
|
return NULL;
|
|
}
|
|
}
|
|
if (address == 0)
|
|
{
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, NULL);
|
|
fprintf_unfiltered (gdb_stdlog,
|
|
" // legacy frame chain NULL }\n");
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Link in the already allocated prev frame. */
|
|
this_frame->prev = prev;
|
|
deprecated_update_frame_base_hack (prev, address);
|
|
|
|
/* This change should not be needed, FIXME! We should determine
|
|
whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
|
|
after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple
|
|
way to express what goes on here.
|
|
|
|
DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places:
|
|
create_new_frame (where the PC is already set up) and here (where
|
|
it isn't). DEPRECATED_INIT_FRAME_PC is only called from here,
|
|
always after DEPRECATED_INIT_EXTRA_FRAME_INFO.
|
|
|
|
The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO
|
|
requires the PC value (which hasn't been set yet). Some other
|
|
machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO
|
|
before they can do DEPRECATED_INIT_FRAME_PC. Phoo.
|
|
|
|
Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
|
|
DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme:
|
|
|
|
SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
|
|
(deprecated_read_fp ()), read_pc ()). Machines with extra frame
|
|
info would do that (or the local equivalent) and then set the
|
|
extra fields.
|
|
|
|
SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
|
|
create_new_frame would no longer init extra frame info;
|
|
SETUP_ARBITRARY_FRAME would have to do that.
|
|
|
|
INIT_PREV_FRAME(fromleaf, prev) Replace
|
|
DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC.
|
|
This should also return a flag saying whether to keep the new
|
|
frame, or whether to discard it, because on some machines (e.g.
|
|
mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID
|
|
called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good
|
|
way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID
|
|
into the extra fields of the new frame). std_frame_pc(fromleaf,
|
|
prev)
|
|
|
|
This is the default setting for INIT_PREV_FRAME. It just does
|
|
what the default DEPRECATED_INIT_FRAME_PC does. Some machines
|
|
will call it from INIT_PREV_FRAME (either at the beginning, the
|
|
end, or in the middle). Some machines won't use it.
|
|
|
|
kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
|
|
|
|
/* NOTE: cagney/2002-11-09: Just ignore the above! There is no
|
|
reason for things to be this complicated.
|
|
|
|
The trick is to assume that there is always a frame. Instead of
|
|
special casing the inner-most frame, create a fake frame
|
|
(containing the hardware registers) that is inner to the
|
|
user-visible inner-most frame (...) and then unwind from that.
|
|
That way architecture code can use the standard
|
|
frame_XX_unwind() functions and not differentiate between the
|
|
inner most and any other case.
|
|
|
|
Since there is always a frame to unwind from, there is always
|
|
somewhere (THIS_FRAME) to store all the info needed to construct
|
|
a new (previous) frame without having to first create it. This
|
|
means that the convolution below - needing to carefully order a
|
|
frame's initialization - isn't needed.
|
|
|
|
The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least
|
|
for a more up-to-date architecture, always calls
|
|
FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but
|
|
without first needing the frame! Instead of the convolution
|
|
below, we could have simply called FRAME_SAVED_PC() and been done
|
|
with it! Note that FRAME_SAVED_PC() is being superseded by
|
|
frame_pc_unwind() and that function does have somewhere to cache
|
|
that PC value. */
|
|
|
|
if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
|
|
DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf, prev);
|
|
|
|
/* This entry is in the frame queue now, which is good since
|
|
FRAME_SAVED_PC may use that queue to figure out its value (see
|
|
tm-sparc.h). We want the PC saved in the inferior frame. */
|
|
if (DEPRECATED_INIT_FRAME_PC_P ())
|
|
deprecated_update_frame_pc_hack (prev,
|
|
DEPRECATED_INIT_FRAME_PC (fromleaf,
|
|
prev));
|
|
|
|
/* If ->frame and ->pc are unchanged, we are in the process of
|
|
getting ourselves into an infinite backtrace. Some architectures
|
|
check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems
|
|
like there is no reason this can't be an architecture-independent
|
|
check. */
|
|
if (get_frame_base (prev) == get_frame_base (this_frame)
|
|
&& get_frame_pc (prev) == get_frame_pc (this_frame))
|
|
{
|
|
this_frame->prev = NULL;
|
|
obstack_free (&frame_cache_obstack, prev);
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, NULL);
|
|
fprintf_unfiltered (gdb_stdlog,
|
|
" // legacy this.id == prev.id }\n");
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Initialize the code used to unwind the frame PREV based on the PC
|
|
(and probably other architectural information). The PC lets you
|
|
check things like the debug info at that point (dwarf2cfi?) and
|
|
use that to decide how the frame should be unwound.
|
|
|
|
If there isn't a FRAME_CHAIN, the code above will have already
|
|
done this. */
|
|
if (prev->unwind == NULL)
|
|
prev->unwind = frame_unwind_find_by_frame (prev->next,
|
|
&prev->prologue_cache);
|
|
|
|
/* If the unwinder provides a frame type, use it. Otherwise
|
|
continue on to that heuristic mess. */
|
|
if (prev->unwind->type != UNKNOWN_FRAME)
|
|
{
|
|
prev->type = prev->unwind->type;
|
|
if (prev->type == NORMAL_FRAME)
|
|
/* FIXME: cagney/2003-06-16: would get_frame_pc() be better? */
|
|
prev->this_id.value.code_addr
|
|
= get_pc_function_start (prev->this_id.value.code_addr);
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, prev);
|
|
fprintf_unfiltered (gdb_stdlog, " } // legacy with unwound type\n");
|
|
}
|
|
return prev;
|
|
}
|
|
|
|
/* NOTE: cagney/2002-11-18: The code segments, found in
|
|
create_new_frame() and get_prev_frame(), that initialize the
|
|
frame's type is subtly different. The latter only updates ->type
|
|
when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
|
|
get_prev_frame() overriding the frame's type when the INIT code
|
|
has previously set it. This is really somewhat bogus. The
|
|
initialization, as seen in create_new_frame(), should occur
|
|
before the INIT function has been called. */
|
|
if (deprecated_pc_in_call_dummy (get_frame_pc (prev)))
|
|
prev->type = DUMMY_FRAME;
|
|
|
|
if (prev->type == NORMAL_FRAME)
|
|
prev->this_id.value.code_addr
|
|
= get_pc_function_start (prev->this_id.value.code_addr);
|
|
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, prev);
|
|
fprintf_unfiltered (gdb_stdlog, " } // legacy with confused type\n");
|
|
}
|
|
|
|
return prev;
|
|
}
|
|
|
|
/* Return a "struct frame_info" corresponding to the frame that called
|
|
THIS_FRAME. Returns NULL if there is no such frame.
|
|
|
|
Unlike get_prev_frame, this function always tries to unwind the
|
|
frame. */
|
|
|
|
static struct frame_info *
|
|
get_prev_frame_1 (struct frame_info *this_frame)
|
|
{
|
|
struct frame_info *prev_frame;
|
|
struct frame_id this_id;
|
|
|
|
gdb_assert (this_frame != NULL);
|
|
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame_1 (this_frame=");
|
|
if (this_frame != NULL)
|
|
fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level);
|
|
else
|
|
fprintf_unfiltered (gdb_stdlog, "<NULL>");
|
|
fprintf_unfiltered (gdb_stdlog, ") ");
|
|
}
|
|
|
|
/* Only try to do the unwind once. */
|
|
if (this_frame->prev_p)
|
|
{
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, this_frame->prev);
|
|
fprintf_unfiltered (gdb_stdlog, " // cached \n");
|
|
}
|
|
return this_frame->prev;
|
|
}
|
|
this_frame->prev_p = 1;
|
|
|
|
/* If any of the old frame initialization methods are around, use
|
|
the legacy get_prev_frame() method. */
|
|
if (legacy_frame_p (current_gdbarch))
|
|
{
|
|
prev_frame = legacy_get_prev_frame (this_frame);
|
|
return prev_frame;
|
|
}
|
|
|
|
/* Check that this frame's ID was valid. If it wasn't, don't try to
|
|
unwind to the prev frame. Be careful to not apply this test to
|
|
the sentinel frame. */
|
|
this_id = get_frame_id (this_frame);
|
|
if (this_frame->level >= 0 && !frame_id_p (this_id))
|
|
{
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, NULL);
|
|
fprintf_unfiltered (gdb_stdlog, " // this ID is NULL }\n");
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Check that this frame's ID isn't inner to (younger, below, next)
|
|
the next frame. This happens when a frame unwind goes backwards.
|
|
Exclude signal trampolines (due to sigaltstack the frame ID can
|
|
go backwards) and sentinel frames (the test is meaningless). */
|
|
if (this_frame->next->level >= 0
|
|
&& this_frame->next->type != SIGTRAMP_FRAME
|
|
&& frame_id_inner (this_id, get_frame_id (this_frame->next)))
|
|
error ("Previous frame inner to this frame (corrupt stack?)");
|
|
|
|
/* Check that this and the next frame are not identical. If they
|
|
are, there is most likely a stack cycle. As with the inner-than
|
|
test above, avoid comparing the inner-most and sentinel frames. */
|
|
if (this_frame->level > 0
|
|
&& frame_id_eq (this_id, get_frame_id (this_frame->next)))
|
|
error ("Previous frame identical to this frame (corrupt stack?)");
|
|
|
|
/* Allocate the new frame but do not wire it in to the frame chain.
|
|
Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
|
|
frame->next to pull some fancy tricks (of course such code is, by
|
|
definition, recursive). Try to prevent it.
|
|
|
|
There is no reason to worry about memory leaks, should the
|
|
remainder of the function fail. The allocated memory will be
|
|
quickly reclaimed when the frame cache is flushed, and the `we've
|
|
been here before' check above will stop repeated memory
|
|
allocation calls. */
|
|
prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
|
|
prev_frame->level = this_frame->level + 1;
|
|
|
|
/* Don't yet compute ->unwind (and hence ->type). It is computed
|
|
on-demand in get_frame_type, frame_register_unwind, and
|
|
get_frame_id. */
|
|
|
|
/* Don't yet compute the frame's ID. It is computed on-demand by
|
|
get_frame_id(). */
|
|
|
|
/* The unwound frame ID is validate at the start of this function,
|
|
as part of the logic to decide if that frame should be further
|
|
unwound, and not here while the prev frame is being created.
|
|
Doing this makes it possible for the user to examine a frame that
|
|
has an invalid frame ID.
|
|
|
|
Some very old VAX code noted: [...] For the sake of argument,
|
|
suppose that the stack is somewhat trashed (which is one reason
|
|
that "info frame" exists). So, return 0 (indicating we don't
|
|
know the address of the arglist) if we don't know what frame this
|
|
frame calls. */
|
|
|
|
/* Link it in. */
|
|
this_frame->prev = prev_frame;
|
|
prev_frame->next = this_frame;
|
|
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "-> ");
|
|
fprint_frame (gdb_stdlog, prev_frame);
|
|
fprintf_unfiltered (gdb_stdlog, " }\n");
|
|
}
|
|
|
|
return prev_frame;
|
|
}
|
|
|
|
/* Debug routine to print a NULL frame being returned. */
|
|
|
|
static void
|
|
frame_debug_got_null_frame (struct ui_file *file,
|
|
struct frame_info *this_frame,
|
|
const char *reason)
|
|
{
|
|
if (frame_debug)
|
|
{
|
|
fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame=");
|
|
if (this_frame != NULL)
|
|
fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level);
|
|
else
|
|
fprintf_unfiltered (gdb_stdlog, "<NULL>");
|
|
fprintf_unfiltered (gdb_stdlog, ") -> // %s}\n", reason);
|
|
}
|
|
}
|
|
|
|
/* Return a structure containing various interesting information about
|
|
the frame that called THIS_FRAME. Returns NULL if there is entier
|
|
no such frame or the frame fails any of a set of target-independent
|
|
condition that should terminate the frame chain (e.g., as unwinding
|
|
past main()).
|
|
|
|
This function should not contain target-dependent tests, such as
|
|
checking whether the program-counter is zero. */
|
|
|
|
struct frame_info *
|
|
get_prev_frame (struct frame_info *this_frame)
|
|
{
|
|
struct frame_info *prev_frame;
|
|
|
|
/* Return the inner-most frame, when the caller passes in NULL. */
|
|
/* NOTE: cagney/2002-11-09: Not sure how this would happen. The
|
|
caller should have previously obtained a valid frame using
|
|
get_selected_frame() and then called this code - only possibility
|
|
I can think of is code behaving badly.
|
|
|
|
NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
|
|
block_innermost_frame(). It does the sequence: frame = NULL;
|
|
while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
|
|
it couldn't be written better, I don't know.
|
|
|
|
NOTE: cagney/2003-01-11: I suspect what is happening in
|
|
block_innermost_frame() is, when the target has no state
|
|
(registers, memory, ...), it is still calling this function. The
|
|
assumption being that this function will return NULL indicating
|
|
that a frame isn't possible, rather than checking that the target
|
|
has state and then calling get_current_frame() and
|
|
get_prev_frame(). This is a guess mind. */
|
|
if (this_frame == NULL)
|
|
{
|
|
/* NOTE: cagney/2002-11-09: There was a code segment here that
|
|
would error out when CURRENT_FRAME was NULL. The comment
|
|
that went with it made the claim ...
|
|
|
|
``This screws value_of_variable, which just wants a nice
|
|
clean NULL return from block_innermost_frame if there are no
|
|
frames. I don't think I've ever seen this message happen
|
|
otherwise. And returning NULL here is a perfectly legitimate
|
|
thing to do.''
|
|
|
|
Per the above, this code shouldn't even be called with a NULL
|
|
THIS_FRAME. */
|
|
frame_debug_got_null_frame (gdb_stdlog, this_frame, "this_frame NULL");
|
|
return current_frame;
|
|
}
|
|
|
|
/* There is always a frame. If this assertion fails, suspect that
|
|
something should be calling get_selected_frame() or
|
|
get_current_frame(). */
|
|
gdb_assert (this_frame != NULL);
|
|
|
|
/* Make sure we pass an address within THIS_FRAME's code block to
|
|
inside_main_func(). Otherwise, we might stop unwinding at a
|
|
function which has a call instruction as its last instruction if
|
|
that function immediately precedes main(). */
|
|
if (this_frame->level >= 0
|
|
&& !backtrace_past_main
|
|
&& inside_main_func (get_frame_address_in_block (this_frame)))
|
|
/* Don't unwind past main(), but 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(), that just happens. */
|
|
{
|
|
frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside main func");
|
|
return NULL;
|
|
}
|
|
|
|
if (this_frame->level > backtrace_limit)
|
|
{
|
|
error ("Backtrace limit of %d exceeded", backtrace_limit);
|
|
}
|
|
|
|
/* If we're already inside the entry function for the main objfile,
|
|
then it isn't valid. Don't apply this test to a dummy frame -
|
|
dummy frame PCs typically land in the entry func. Don't apply
|
|
this test to the sentinel frame. Sentinel frames should always
|
|
be allowed to unwind. */
|
|
/* NOTE: cagney/2003-02-25: Don't enable until someone has found
|
|
hard evidence that this is needed. */
|
|
/* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func() -
|
|
wasn't checking for "main" in the minimal symbols. With that
|
|
fixed asm-source tests now stop in "main" instead of halting the
|
|
backtrace in weird and wonderful ways somewhere inside the entry
|
|
file. Suspect that tests for inside the entry file/func were
|
|
added to work around that (now fixed) case. */
|
|
/* NOTE: cagney/2003-07-15: danielj (if I'm reading it right)
|
|
suggested having the inside_entry_func test use the
|
|
inside_main_func() msymbol trick (along with entry_point_address()
|
|
I guess) to determine the address range of the start function.
|
|
That should provide a far better stopper than the current
|
|
heuristics. */
|
|
/* NOTE: cagney/2003-07-15: Need to add a "set backtrace
|
|
beyond-entry-func" command so that this can be selectively
|
|
disabled. */
|
|
if (0
|
|
#if 0
|
|
&& backtrace_beyond_entry_func
|
|
#endif
|
|
&& this_frame->type != DUMMY_FRAME && this_frame->level >= 0
|
|
&& inside_entry_func (this_frame))
|
|
{
|
|
frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside entry func");
|
|
return NULL;
|
|
}
|
|
|
|
return get_prev_frame_1 (this_frame);
|
|
}
|
|
|
|
CORE_ADDR
|
|
get_frame_pc (struct frame_info *frame)
|
|
{
|
|
gdb_assert (frame->next != NULL);
|
|
return frame_pc_unwind (frame->next);
|
|
}
|
|
|
|
/* Return an address of that falls within the frame's code block. */
|
|
|
|
CORE_ADDR
|
|
frame_unwind_address_in_block (struct frame_info *next_frame)
|
|
{
|
|
/* A draft address. */
|
|
CORE_ADDR pc = frame_pc_unwind (next_frame);
|
|
|
|
/* If THIS frame is not inner most (i.e., NEXT isn't the sentinel),
|
|
and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS
|
|
frame's PC ends up pointing at the instruction fallowing the
|
|
"call". Adjust that PC value so that it falls on the call
|
|
instruction (which, hopefully, falls within THIS frame's code
|
|
block. So far it's proved to be a very good approximation. See
|
|
get_frame_type() for why ->type can't be used. */
|
|
if (next_frame->level >= 0
|
|
&& get_frame_type (next_frame) == NORMAL_FRAME)
|
|
--pc;
|
|
return pc;
|
|
}
|
|
|
|
CORE_ADDR
|
|
get_frame_address_in_block (struct frame_info *this_frame)
|
|
{
|
|
return frame_unwind_address_in_block (this_frame->next);
|
|
}
|
|
|
|
static int
|
|
pc_notcurrent (struct frame_info *frame)
|
|
{
|
|
/* If FRAME is not the innermost frame, that normally means that
|
|
FRAME->pc points at the return instruction (which is *after* the
|
|
call instruction), and we want to get the line containing the
|
|
call (because the call is where the user thinks the program is).
|
|
However, if the next frame is either a SIGTRAMP_FRAME or a
|
|
DUMMY_FRAME, then the next frame will contain a saved interrupt
|
|
PC and such a PC indicates the current (rather than next)
|
|
instruction/line, consequently, for such cases, want to get the
|
|
line containing fi->pc. */
|
|
struct frame_info *next = get_next_frame (frame);
|
|
int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME);
|
|
return notcurrent;
|
|
}
|
|
|
|
void
|
|
find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal)
|
|
{
|
|
(*sal) = find_pc_line (get_frame_pc (frame), pc_notcurrent (frame));
|
|
}
|
|
|
|
/* Per "frame.h", return the ``address'' of the frame. Code should
|
|
really be using get_frame_id(). */
|
|
CORE_ADDR
|
|
get_frame_base (struct frame_info *fi)
|
|
{
|
|
return get_frame_id (fi).stack_addr;
|
|
}
|
|
|
|
/* High-level offsets into the frame. Used by the debug info. */
|
|
|
|
CORE_ADDR
|
|
get_frame_base_address (struct frame_info *fi)
|
|
{
|
|
if (get_frame_type (fi) != NORMAL_FRAME)
|
|
return 0;
|
|
if (fi->base == NULL)
|
|
fi->base = frame_base_find_by_frame (fi->next);
|
|
/* Sneaky: If the low-level unwind and high-level base code share a
|
|
common unwinder, let them share the prologue cache. */
|
|
if (fi->base->unwind == fi->unwind)
|
|
return fi->base->this_base (fi->next, &fi->prologue_cache);
|
|
return fi->base->this_base (fi->next, &fi->base_cache);
|
|
}
|
|
|
|
CORE_ADDR
|
|
get_frame_locals_address (struct frame_info *fi)
|
|
{
|
|
void **cache;
|
|
if (get_frame_type (fi) != NORMAL_FRAME)
|
|
return 0;
|
|
/* If there isn't a frame address method, find it. */
|
|
if (fi->base == NULL)
|
|
fi->base = frame_base_find_by_frame (fi->next);
|
|
/* Sneaky: If the low-level unwind and high-level base code share a
|
|
common unwinder, let them share the prologue cache. */
|
|
if (fi->base->unwind == fi->unwind)
|
|
cache = &fi->prologue_cache;
|
|
else
|
|
cache = &fi->base_cache;
|
|
return fi->base->this_locals (fi->next, cache);
|
|
}
|
|
|
|
CORE_ADDR
|
|
get_frame_args_address (struct frame_info *fi)
|
|
{
|
|
void **cache;
|
|
if (get_frame_type (fi) != NORMAL_FRAME)
|
|
return 0;
|
|
/* If there isn't a frame address method, find it. */
|
|
if (fi->base == NULL)
|
|
fi->base = frame_base_find_by_frame (fi->next);
|
|
/* Sneaky: If the low-level unwind and high-level base code share a
|
|
common unwinder, let them share the prologue cache. */
|
|
if (fi->base->unwind == fi->unwind)
|
|
cache = &fi->prologue_cache;
|
|
else
|
|
cache = &fi->base_cache;
|
|
return fi->base->this_args (fi->next, cache);
|
|
}
|
|
|
|
/* Level of the selected frame: 0 for innermost, 1 for its caller, ...
|
|
or -1 for a NULL frame. */
|
|
|
|
int
|
|
frame_relative_level (struct frame_info *fi)
|
|
{
|
|
if (fi == NULL)
|
|
return -1;
|
|
else
|
|
return fi->level;
|
|
}
|
|
|
|
enum frame_type
|
|
get_frame_type (struct frame_info *frame)
|
|
{
|
|
/* Some legacy code, e.g, mips_init_extra_frame_info() wants
|
|
to determine the frame's type prior to it being completely
|
|
initialized. Don't attempt to lazily initialize ->unwind for
|
|
legacy code. It will be initialized in legacy_get_prev_frame(). */
|
|
if (frame->unwind == NULL && !legacy_frame_p (current_gdbarch))
|
|
{
|
|
/* Initialize the frame's unwinder because that's what
|
|
provides the frame's type. */
|
|
frame->unwind = frame_unwind_find_by_frame (frame->next,
|
|
&frame->prologue_cache);
|
|
/* FIXME: cagney/2004-05-01: Should instead just use
|
|
->unwind->type. Unfortunately, legacy_get_prev_frame is
|
|
still explicitly setting the type. Eliminate that method and
|
|
this field can be eliminated. */
|
|
frame->type = frame->unwind->type;
|
|
}
|
|
if (frame->type == UNKNOWN_FRAME)
|
|
return NORMAL_FRAME;
|
|
else
|
|
return frame->type;
|
|
}
|
|
|
|
struct frame_extra_info *
|
|
get_frame_extra_info (struct frame_info *fi)
|
|
{
|
|
return fi->extra_info;
|
|
}
|
|
|
|
struct frame_extra_info *
|
|
frame_extra_info_zalloc (struct frame_info *fi, long size)
|
|
{
|
|
fi->extra_info = frame_obstack_zalloc (size);
|
|
return fi->extra_info;
|
|
}
|
|
|
|
void
|
|
deprecated_update_frame_pc_hack (struct frame_info *frame, CORE_ADDR pc)
|
|
{
|
|
if (frame_debug)
|
|
fprintf_unfiltered (gdb_stdlog,
|
|
"{ deprecated_update_frame_pc_hack (frame=%d,pc=0x%s) }\n",
|
|
frame->level, paddr_nz (pc));
|
|
/* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
|
|
maintaining a locally allocated frame object. Since such frames
|
|
are not in the frame chain, it isn't possible to assume that the
|
|
frame has a next. Sigh. */
|
|
if (frame->next != NULL)
|
|
{
|
|
/* While we're at it, update this frame's cached PC value, found
|
|
in the next frame. Oh for the day when "struct frame_info"
|
|
is opaque and this hack on hack can just go away. */
|
|
frame->next->prev_pc.value = pc;
|
|
frame->next->prev_pc.p = 1;
|
|
}
|
|
}
|
|
|
|
void
|
|
deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base)
|
|
{
|
|
if (frame_debug)
|
|
fprintf_unfiltered (gdb_stdlog,
|
|
"{ deprecated_update_frame_base_hack (frame=%d,base=0x%s) }\n",
|
|
frame->level, paddr_nz (base));
|
|
/* See comment in "frame.h". */
|
|
frame->this_id.value.stack_addr = base;
|
|
}
|
|
|
|
struct frame_info *
|
|
deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs,
|
|
long sizeof_extra_info)
|
|
{
|
|
struct frame_info *frame = XMALLOC (struct frame_info);
|
|
memset (frame, 0, sizeof (*frame));
|
|
frame->this_id.p = 1;
|
|
make_cleanup (xfree, frame);
|
|
if (sizeof_saved_regs > 0)
|
|
{
|
|
frame->saved_regs = xcalloc (1, sizeof_saved_regs);
|
|
make_cleanup (xfree, frame->saved_regs);
|
|
}
|
|
if (sizeof_extra_info > 0)
|
|
{
|
|
frame->extra_info = xcalloc (1, sizeof_extra_info);
|
|
make_cleanup (xfree, frame->extra_info);
|
|
}
|
|
return frame;
|
|
}
|
|
|
|
/* Memory access methods. */
|
|
|
|
void
|
|
get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr, void *buf,
|
|
int len)
|
|
{
|
|
read_memory (addr, buf, len);
|
|
}
|
|
|
|
LONGEST
|
|
get_frame_memory_signed (struct frame_info *this_frame, CORE_ADDR addr,
|
|
int len)
|
|
{
|
|
return read_memory_integer (addr, len);
|
|
}
|
|
|
|
ULONGEST
|
|
get_frame_memory_unsigned (struct frame_info *this_frame, CORE_ADDR addr,
|
|
int len)
|
|
{
|
|
return read_memory_unsigned_integer (addr, len);
|
|
}
|
|
|
|
int
|
|
safe_frame_unwind_memory (struct frame_info *this_frame,
|
|
CORE_ADDR addr, void *buf, int len)
|
|
{
|
|
/* NOTE: read_memory_nobpt returns zero on success! */
|
|
return !read_memory_nobpt (addr, buf, len);
|
|
}
|
|
|
|
/* Architecture method. */
|
|
|
|
struct gdbarch *
|
|
get_frame_arch (struct frame_info *this_frame)
|
|
{
|
|
return current_gdbarch;
|
|
}
|
|
|
|
/* Stack pointer methods. */
|
|
|
|
CORE_ADDR
|
|
get_frame_sp (struct frame_info *this_frame)
|
|
{
|
|
return frame_sp_unwind (this_frame->next);
|
|
}
|
|
|
|
CORE_ADDR
|
|
frame_sp_unwind (struct frame_info *next_frame)
|
|
{
|
|
/* Normality - an architecture that provides a way of obtaining any
|
|
frame inner-most address. */
|
|
if (gdbarch_unwind_sp_p (current_gdbarch))
|
|
return gdbarch_unwind_sp (current_gdbarch, next_frame);
|
|
/* Things are looking grim. If it's the inner-most frame and there
|
|
is a TARGET_READ_SP, then that can be used. */
|
|
if (next_frame->level < 0 && TARGET_READ_SP_P ())
|
|
return TARGET_READ_SP ();
|
|
/* Now things are really are grim. Hope that the value returned by
|
|
the SP_REGNUM register is meaningful. */
|
|
if (SP_REGNUM >= 0)
|
|
{
|
|
ULONGEST sp;
|
|
frame_unwind_unsigned_register (next_frame, SP_REGNUM, &sp);
|
|
return sp;
|
|
}
|
|
internal_error (__FILE__, __LINE__, "Missing unwind SP method");
|
|
}
|
|
|
|
|
|
int
|
|
legacy_frame_p (struct gdbarch *current_gdbarch)
|
|
{
|
|
if (DEPRECATED_INIT_FRAME_PC_P ()
|
|
|| DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()
|
|
|| DEPRECATED_FRAME_CHAIN_P ())
|
|
/* No question, it's a legacy frame. */
|
|
return 1;
|
|
if (gdbarch_unwind_dummy_id_p (current_gdbarch))
|
|
/* No question, it's not a legacy frame (provided none of the
|
|
deprecated methods checked above are present that is). */
|
|
return 0;
|
|
if (DEPRECATED_TARGET_READ_FP_P ()
|
|
|| DEPRECATED_FP_REGNUM >= 0)
|
|
/* Assume it's legacy. If you're trying to convert a legacy frame
|
|
target to the new mechanism, get rid of these. legacy
|
|
get_prev_frame() requires these when unwind_frame_id() isn't
|
|
available. */
|
|
return 1;
|
|
/* Default to assuming that it's brand new code, and hence not
|
|
legacy. Force it down the non-legacy path so that the new code
|
|
uses the new frame mechanism from day one. Dummy frames won't
|
|
work very well but we can live with that. */
|
|
return 0;
|
|
}
|
|
|
|
extern initialize_file_ftype _initialize_frame; /* -Wmissing-prototypes */
|
|
|
|
static struct cmd_list_element *set_backtrace_cmdlist;
|
|
static struct cmd_list_element *show_backtrace_cmdlist;
|
|
|
|
static void
|
|
set_backtrace_cmd (char *args, int from_tty)
|
|
{
|
|
help_list (set_backtrace_cmdlist, "set backtrace ", -1, gdb_stdout);
|
|
}
|
|
|
|
static void
|
|
show_backtrace_cmd (char *args, int from_tty)
|
|
{
|
|
cmd_show_list (show_backtrace_cmdlist, from_tty, "");
|
|
}
|
|
|
|
void
|
|
_initialize_frame (void)
|
|
{
|
|
obstack_init (&frame_cache_obstack);
|
|
|
|
observer_attach_target_changed (frame_observer_target_changed);
|
|
|
|
add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, "\
|
|
Set backtrace specific variables.\n\
|
|
Configure backtrace variables such as the backtrace limit",
|
|
&set_backtrace_cmdlist, "set backtrace ",
|
|
0/*allow-unknown*/, &setlist);
|
|
add_prefix_cmd ("backtrace", class_maintenance, show_backtrace_cmd, "\
|
|
Show backtrace specific variables\n\
|
|
Show backtrace variables such as the backtrace limit",
|
|
&show_backtrace_cmdlist, "show backtrace ",
|
|
0/*allow-unknown*/, &showlist);
|
|
|
|
add_setshow_boolean_cmd ("past-main", class_obscure,
|
|
&backtrace_past_main, "\
|
|
Set whether backtraces should continue past \"main\".\n\
|
|
Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
|
|
the backtrace at \"main\". Set this variable if you need to see the rest\n\
|
|
of the stack trace.", "\
|
|
Show whether backtraces should continue past \"main\".\n\
|
|
Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
|
|
the backtrace at \"main\". Set this variable if you need to see the rest\n\
|
|
of the stack trace.",
|
|
NULL, NULL, &set_backtrace_cmdlist,
|
|
&show_backtrace_cmdlist);
|
|
|
|
add_setshow_uinteger_cmd ("limit", class_obscure,
|
|
&backtrace_limit, "\
|
|
Set an upper bound on the number of backtrace levels.\n\
|
|
No more than the specified number of frames can be displayed or examined.\n\
|
|
Zero is unlimited.", "\
|
|
Show the upper bound on the number of backtrace levels.",
|
|
NULL, NULL, &set_backtrace_cmdlist,
|
|
&show_backtrace_cmdlist);
|
|
|
|
/* Debug this files internals. */
|
|
add_show_from_set (add_set_cmd ("frame", class_maintenance, var_zinteger,
|
|
&frame_debug, "Set frame debugging.\n\
|
|
When non-zero, frame specific internal debugging is enabled.", &setdebuglist),
|
|
&showdebuglist);
|
|
}
|