1109 lines
32 KiB
C
1109 lines
32 KiB
C
/* Get info from stack frames;
|
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convert between frames, blocks, functions and pc values.
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Copyright 1986, 1987, 1988, 1989, 1991, 1994, 1995, 1996, 1997
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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, Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "symtab.h"
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#include "bfd.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "frame.h"
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#include "gdbcore.h"
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#include "value.h" /* for read_register */
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#include "target.h" /* for target_has_stack */
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#include "inferior.h" /* for read_pc */
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#include "annotate.h"
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/* Is ADDR inside the startup file? Note that if your machine
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has a way to detect the bottom of the stack, there is no need
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to call this function from FRAME_CHAIN_VALID; the reason for
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doing so is that some machines have no way of detecting bottom
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of stack.
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A PC of zero is always considered to be the bottom of the stack. */
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int
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inside_entry_file (addr)
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CORE_ADDR addr;
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{
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if (addr == 0)
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return 1;
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if (symfile_objfile == 0)
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return 0;
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#if CALL_DUMMY_LOCATION == AT_ENTRY_POINT
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/* Do not stop backtracing if the pc is in the call dummy
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at the entry point. */
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/* FIXME: Won't always work with zeros for the last two arguments */
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if (PC_IN_CALL_DUMMY (addr, 0, 0))
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return 0;
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#endif
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return (addr >= symfile_objfile -> ei.entry_file_lowpc &&
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addr < symfile_objfile -> ei.entry_file_highpc);
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}
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/* Test a specified PC value to see if it is in the range of addresses
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that correspond to the main() function. See comments above for why
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we might want to do this.
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Typically called from FRAME_CHAIN_VALID.
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A PC of zero is always considered to be the bottom of the stack. */
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int
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inside_main_func (pc)
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CORE_ADDR pc;
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{
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if (pc == 0)
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return 1;
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if (symfile_objfile == 0)
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return 0;
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/* If the addr range is not set up at symbol reading time, set it up now.
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This is for FRAME_CHAIN_VALID_ALTERNATE. I do this for coff, because
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it is unable to set it up and symbol reading time. */
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if (symfile_objfile -> ei.main_func_lowpc == INVALID_ENTRY_LOWPC &&
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symfile_objfile -> ei.main_func_highpc == INVALID_ENTRY_HIGHPC)
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{
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struct symbol *mainsym;
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mainsym = lookup_symbol ("main", NULL, VAR_NAMESPACE, NULL, NULL);
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if (mainsym && SYMBOL_CLASS(mainsym) == LOC_BLOCK)
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{
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symfile_objfile->ei.main_func_lowpc = BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym));
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symfile_objfile->ei.main_func_highpc = BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym));
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}
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}
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return (symfile_objfile -> ei.main_func_lowpc <= pc &&
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symfile_objfile -> ei.main_func_highpc > pc);
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}
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/* Test a specified PC value to see if it is in the range of addresses
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that correspond to the process entry point function. See comments
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in objfiles.h for why we might want to do this.
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Typically called from FRAME_CHAIN_VALID.
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A PC of zero is always considered to be the bottom of the stack. */
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int
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inside_entry_func (pc)
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CORE_ADDR pc;
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{
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if (pc == 0)
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return 1;
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if (symfile_objfile == 0)
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return 0;
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#if CALL_DUMMY_LOCATION == AT_ENTRY_POINT
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/* Do not stop backtracing if the pc is in the call dummy
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at the entry point. */
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/* FIXME: Won't always work with zeros for the last two arguments */
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if (PC_IN_CALL_DUMMY (pc, 0, 0))
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return 0;
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#endif
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return (symfile_objfile -> ei.entry_func_lowpc <= pc &&
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symfile_objfile -> ei.entry_func_highpc > pc);
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}
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/* Info about the innermost stack frame (contents of FP register) */
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static struct frame_info *current_frame;
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/* Cache for frame addresses already read by gdb. Valid only while
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inferior is stopped. Control variables for the frame cache should
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be local to this module. */
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struct obstack frame_cache_obstack;
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/* Return the innermost (currently executing) stack frame. */
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struct frame_info *
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get_current_frame ()
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{
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if (current_frame == NULL)
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{
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if (target_has_stack)
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current_frame = create_new_frame (read_fp (), read_pc ());
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else
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error ("No stack.");
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}
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return current_frame;
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}
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void
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set_current_frame (frame)
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struct frame_info *frame;
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{
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current_frame = frame;
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}
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/* Create an arbitrary (i.e. address specified by user) or innermost frame.
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Always returns a non-NULL value. */
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struct frame_info *
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create_new_frame (addr, pc)
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CORE_ADDR addr;
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CORE_ADDR pc;
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{
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struct frame_info *fi;
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char *name;
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fi = (struct frame_info *)
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obstack_alloc (&frame_cache_obstack,
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sizeof (struct frame_info));
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/* Arbitrary frame */
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fi->next = NULL;
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fi->prev = NULL;
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fi->frame = addr;
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fi->pc = pc;
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find_pc_partial_function (pc, &name, (CORE_ADDR *)NULL,(CORE_ADDR *)NULL);
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fi->signal_handler_caller = IN_SIGTRAMP (fi->pc, name);
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#ifdef INIT_EXTRA_FRAME_INFO
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INIT_EXTRA_FRAME_INFO (0, fi);
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#endif
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return fi;
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}
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/* Return the frame that called FI.
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If FI is the original frame (it has no caller), return 0. */
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struct frame_info *
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get_prev_frame (frame)
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struct frame_info *frame;
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{
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return get_prev_frame_info (frame);
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}
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/* Return the frame that FRAME calls (NULL if FRAME is the innermost
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frame). */
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struct frame_info *
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get_next_frame (frame)
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struct frame_info *frame;
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{
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return frame->next;
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}
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/* Flush the entire frame cache. */
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void
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flush_cached_frames ()
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{
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/* Since we can't really be sure what the first object allocated was */
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obstack_free (&frame_cache_obstack, 0);
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obstack_init (&frame_cache_obstack);
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current_frame = NULL; /* Invalidate cache */
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select_frame (NULL, -1);
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annotate_frames_invalid ();
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}
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/* Flush the frame cache, and start a new one if necessary. */
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void
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reinit_frame_cache ()
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{
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flush_cached_frames ();
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/* FIXME: The inferior_pid test is wrong if there is a corefile. */
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if (inferior_pid != 0)
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{
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select_frame (get_current_frame (), 0);
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}
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}
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/* If a machine allows frameless functions, it should define a macro
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FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) in param.h. FI is the struct
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frame_info for the frame, and FRAMELESS should be set to nonzero
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if it represents a frameless function invocation. */
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/* Return nonzero if the function for this frame lacks a prologue. Many
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machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
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function. */
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int
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frameless_look_for_prologue (frame)
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struct frame_info *frame;
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{
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CORE_ADDR func_start, after_prologue;
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func_start = get_pc_function_start (frame->pc);
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if (func_start)
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{
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func_start += FUNCTION_START_OFFSET;
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after_prologue = func_start;
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#ifdef SKIP_PROLOGUE_FRAMELESS_P
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/* This is faster, since only care whether there *is* a prologue,
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not how long it is. */
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SKIP_PROLOGUE_FRAMELESS_P (after_prologue);
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#else
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SKIP_PROLOGUE (after_prologue);
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#endif
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return after_prologue == func_start;
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}
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else if (frame->pc == 0)
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/* A frame with a zero PC is usually created by dereferencing a NULL
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function pointer, normally causing an immediate core dump of the
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inferior. Mark function as frameless, as the inferior has no chance
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of setting up a stack frame. */
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return 1;
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else
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/* If we can't find the start of the function, we don't really
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know whether the function is frameless, but we should be able
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to get a reasonable (i.e. best we can do under the
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circumstances) backtrace by saying that it isn't. */
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return 0;
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}
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/* Default a few macros that people seldom redefine. */
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#if !defined (INIT_FRAME_PC)
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#define INIT_FRAME_PC(fromleaf, prev) \
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prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
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prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
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#endif
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#ifndef FRAME_CHAIN_COMBINE
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#define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
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#endif
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/* Return a structure containing various interesting information
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about the frame that called NEXT_FRAME. Returns NULL
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if there is no such frame. */
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struct frame_info *
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get_prev_frame_info (next_frame)
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struct frame_info *next_frame;
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{
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CORE_ADDR address = 0;
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struct frame_info *prev;
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int fromleaf = 0;
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char *name;
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/* If the requested entry is in the cache, return it.
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Otherwise, figure out what the address should be for the entry
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we're about to add to the cache. */
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if (!next_frame)
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{
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#if 0
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/* This screws value_of_variable, which just wants a nice clean
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NULL return from block_innermost_frame if there are no frames.
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I don't think I've ever seen this message happen otherwise.
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And returning NULL here is a perfectly legitimate thing to do. */
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if (!current_frame)
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{
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error ("You haven't set up a process's stack to examine.");
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}
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#endif
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return current_frame;
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}
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/* If we have the prev one, return it */
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if (next_frame->prev)
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return next_frame->prev;
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/* On some machines it is possible to call a function without
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setting up a stack frame for it. On these machines, we
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define this macro to take two args; a frameinfo pointer
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identifying a frame and a variable to set or clear if it is
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or isn't leafless. */
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#ifdef FRAMELESS_FUNCTION_INVOCATION
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/* Still don't want to worry about this except on the innermost
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frame. This macro will set FROMLEAF if NEXT_FRAME is a
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frameless function invocation. */
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if (!(next_frame->next))
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{
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FRAMELESS_FUNCTION_INVOCATION (next_frame, fromleaf);
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if (fromleaf)
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address = FRAME_FP (next_frame);
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}
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#endif
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if (!fromleaf)
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{
|
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/* Two macros defined in tm.h specify the machine-dependent
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actions to be performed here.
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First, get the frame's chain-pointer.
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If that is zero, the frame is the outermost frame or a leaf
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called by the outermost frame. This means that if start
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calls main without a frame, we'll return 0 (which is fine
|
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anyway).
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Nope; there's a problem. This also returns when the current
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routine is a leaf of main. This is unacceptable. We move
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this to after the ffi test; I'd rather have backtraces from
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start go curfluy than have an abort called from main not show
|
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main. */
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address = FRAME_CHAIN (next_frame);
|
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if (!FRAME_CHAIN_VALID (address, next_frame))
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return 0;
|
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address = FRAME_CHAIN_COMBINE (address, next_frame);
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}
|
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if (address == 0)
|
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return 0;
|
||
|
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prev = (struct frame_info *)
|
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obstack_alloc (&frame_cache_obstack,
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sizeof (struct frame_info));
|
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|
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if (next_frame)
|
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next_frame->prev = prev;
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prev->next = next_frame;
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prev->prev = (struct frame_info *) 0;
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prev->frame = address;
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prev->signal_handler_caller = 0;
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/* This change should not be needed, FIXME! We should
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determine whether any targets *need* INIT_FRAME_PC to happen
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after INIT_EXTRA_FRAME_INFO and come up with a simple way to
|
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express what goes on here.
|
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INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
|
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(where the PC is already set up) and here (where it isn't).
|
||
INIT_FRAME_PC is only called from here, always after
|
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INIT_EXTRA_FRAME_INFO.
|
||
|
||
The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
|
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value (which hasn't been set yet). Some other machines appear to
|
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require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
|
||
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We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
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||
an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
|
||
|
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Assuming that some machines need INIT_FRAME_PC after
|
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INIT_EXTRA_FRAME_INFO, one possible scheme:
|
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|
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SETUP_INNERMOST_FRAME()
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Default version is just create_new_frame (read_fp ()),
|
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read_pc ()). Machines with extra frame info would do that (or the
|
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local equivalent) and then set the extra fields.
|
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SETUP_ARBITRARY_FRAME(argc, argv)
|
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Only change here is that create_new_frame would no longer init extra
|
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frame info; SETUP_ARBITRARY_FRAME would have to do that.
|
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INIT_PREV_FRAME(fromleaf, prev)
|
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Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. This should
|
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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 FRAME_CHAIN_VALID called *before*
|
||
INIT_EXTRA_FRAME_INFO (there is no good way to get information
|
||
deduced in 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 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. */
|
||
|
||
#ifdef INIT_FRAME_PC_FIRST
|
||
INIT_FRAME_PC_FIRST (fromleaf, prev);
|
||
#endif
|
||
|
||
#ifdef INIT_EXTRA_FRAME_INFO
|
||
INIT_EXTRA_FRAME_INFO(fromleaf, prev);
|
||
#endif
|
||
|
||
/* 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. */
|
||
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 FRAME_CHAIN or thereabouts, but it seems like there is no reason
|
||
this can't be an architecture-independent check. */
|
||
if (next_frame != NULL)
|
||
{
|
||
if (prev->frame == next_frame->frame
|
||
&& prev->pc == next_frame->pc)
|
||
{
|
||
next_frame->prev = NULL;
|
||
obstack_free (&frame_cache_obstack, prev);
|
||
return NULL;
|
||
}
|
||
}
|
||
|
||
find_pc_partial_function (prev->pc, &name,
|
||
(CORE_ADDR *)NULL,(CORE_ADDR *)NULL);
|
||
if (IN_SIGTRAMP (prev->pc, name))
|
||
prev->signal_handler_caller = 1;
|
||
|
||
return prev;
|
||
}
|
||
|
||
CORE_ADDR
|
||
get_frame_pc (frame)
|
||
struct frame_info *frame;
|
||
{
|
||
return frame->pc;
|
||
}
|
||
|
||
#if defined (FRAME_FIND_SAVED_REGS)
|
||
/* Find the addresses in which registers are saved in FRAME. */
|
||
|
||
void
|
||
get_frame_saved_regs (frame, saved_regs_addr)
|
||
struct frame_info *frame;
|
||
struct frame_saved_regs *saved_regs_addr;
|
||
{
|
||
FRAME_FIND_SAVED_REGS (frame, *saved_regs_addr);
|
||
}
|
||
#endif
|
||
|
||
/* Return the innermost lexical block in execution
|
||
in a specified stack frame. The frame address is assumed valid. */
|
||
|
||
struct block *
|
||
get_frame_block (frame)
|
||
struct frame_info *frame;
|
||
{
|
||
CORE_ADDR pc;
|
||
|
||
pc = frame->pc;
|
||
if (frame->next != 0 && frame->next->signal_handler_caller == 0)
|
||
/* We are not in the innermost frame and we were not interrupted
|
||
by a signal. We need to subtract one to get the correct block,
|
||
in case the call instruction was the last instruction of the block.
|
||
If there are any machines on which the saved pc does not point to
|
||
after the call insn, we probably want to make frame->pc point after
|
||
the call insn anyway. */
|
||
--pc;
|
||
return block_for_pc (pc);
|
||
}
|
||
|
||
struct block *
|
||
get_current_block ()
|
||
{
|
||
return block_for_pc (read_pc ());
|
||
}
|
||
|
||
CORE_ADDR
|
||
get_pc_function_start (pc)
|
||
CORE_ADDR pc;
|
||
{
|
||
register struct block *bl;
|
||
register struct symbol *symbol;
|
||
register struct minimal_symbol *msymbol;
|
||
CORE_ADDR fstart;
|
||
|
||
if ((bl = block_for_pc (pc)) != NULL &&
|
||
(symbol = block_function (bl)) != NULL)
|
||
{
|
||
bl = SYMBOL_BLOCK_VALUE (symbol);
|
||
fstart = BLOCK_START (bl);
|
||
}
|
||
else if ((msymbol = lookup_minimal_symbol_by_pc (pc)) != NULL)
|
||
{
|
||
fstart = SYMBOL_VALUE_ADDRESS (msymbol);
|
||
}
|
||
else
|
||
{
|
||
fstart = 0;
|
||
}
|
||
return (fstart);
|
||
}
|
||
|
||
/* Return the symbol for the function executing in frame FRAME. */
|
||
|
||
struct symbol *
|
||
get_frame_function (frame)
|
||
struct frame_info *frame;
|
||
{
|
||
register struct block *bl = get_frame_block (frame);
|
||
if (bl == 0)
|
||
return 0;
|
||
return block_function (bl);
|
||
}
|
||
|
||
/* Return the blockvector immediately containing the innermost lexical block
|
||
containing the specified pc value, or 0 if there is none.
|
||
PINDEX is a pointer to the index value of the block. If PINDEX
|
||
is NULL, we don't pass this information back to the caller. */
|
||
|
||
struct blockvector *
|
||
blockvector_for_pc (pc, pindex)
|
||
register CORE_ADDR pc;
|
||
int *pindex;
|
||
{
|
||
register struct block *b;
|
||
register int bot, top, half;
|
||
register struct symtab *s;
|
||
struct blockvector *bl;
|
||
|
||
/* First search all symtabs for one whose file contains our pc */
|
||
s = find_pc_symtab (pc);
|
||
if (s == 0)
|
||
return 0;
|
||
|
||
bl = BLOCKVECTOR (s);
|
||
b = BLOCKVECTOR_BLOCK (bl, 0);
|
||
|
||
/* Then search that symtab for the smallest block that wins. */
|
||
/* Use binary search to find the last block that starts before PC. */
|
||
|
||
bot = 0;
|
||
top = BLOCKVECTOR_NBLOCKS (bl);
|
||
|
||
while (top - bot > 1)
|
||
{
|
||
half = (top - bot + 1) >> 1;
|
||
b = BLOCKVECTOR_BLOCK (bl, bot + half);
|
||
if (BLOCK_START (b) <= pc)
|
||
bot += half;
|
||
else
|
||
top = bot + half;
|
||
}
|
||
|
||
/* Now search backward for a block that ends after PC. */
|
||
|
||
while (bot >= 0)
|
||
{
|
||
b = BLOCKVECTOR_BLOCK (bl, bot);
|
||
if (BLOCK_END (b) > pc)
|
||
{
|
||
if (pindex)
|
||
*pindex = bot;
|
||
return bl;
|
||
}
|
||
bot--;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Return the innermost lexical block containing the specified pc value,
|
||
or 0 if there is none. */
|
||
|
||
struct block *
|
||
block_for_pc (pc)
|
||
register CORE_ADDR pc;
|
||
{
|
||
register struct blockvector *bl;
|
||
int index;
|
||
|
||
bl = blockvector_for_pc (pc, &index);
|
||
if (bl)
|
||
return BLOCKVECTOR_BLOCK (bl, index);
|
||
return 0;
|
||
}
|
||
|
||
/* Return the function containing pc value PC.
|
||
Returns 0 if function is not known. */
|
||
|
||
struct symbol *
|
||
find_pc_function (pc)
|
||
CORE_ADDR pc;
|
||
{
|
||
register struct block *b = block_for_pc (pc);
|
||
if (b == 0)
|
||
return 0;
|
||
return block_function (b);
|
||
}
|
||
|
||
/* These variables are used to cache the most recent result
|
||
* of find_pc_partial_function. */
|
||
|
||
static CORE_ADDR cache_pc_function_low = 0;
|
||
static CORE_ADDR cache_pc_function_high = 0;
|
||
static char *cache_pc_function_name = 0;
|
||
|
||
/* Clear cache, e.g. when symbol table is discarded. */
|
||
|
||
void
|
||
clear_pc_function_cache()
|
||
{
|
||
cache_pc_function_low = 0;
|
||
cache_pc_function_high = 0;
|
||
cache_pc_function_name = (char *)0;
|
||
}
|
||
|
||
/* Finds the "function" (text symbol) that is smaller than PC but
|
||
greatest of all of the potential text symbols. Sets *NAME and/or
|
||
*ADDRESS conditionally if that pointer is non-null. If ENDADDR is
|
||
non-null, then set *ENDADDR to be the end of the function
|
||
(exclusive), but passing ENDADDR as non-null means that the
|
||
function might cause symbols to be read. This function either
|
||
succeeds or fails (not halfway succeeds). If it succeeds, it sets
|
||
*NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
|
||
If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero
|
||
and returns 0. */
|
||
|
||
int
|
||
find_pc_partial_function (pc, name, address, endaddr)
|
||
CORE_ADDR pc;
|
||
char **name;
|
||
CORE_ADDR *address;
|
||
CORE_ADDR *endaddr;
|
||
{
|
||
struct partial_symtab *pst;
|
||
struct symbol *f;
|
||
struct minimal_symbol *msymbol;
|
||
struct partial_symbol *psb;
|
||
struct obj_section *sec;
|
||
|
||
if (pc >= cache_pc_function_low && pc < cache_pc_function_high)
|
||
goto return_cached_value;
|
||
|
||
/* If sigtramp is in the u area, it counts as a function (especially
|
||
important for step_1). */
|
||
#if defined SIGTRAMP_START
|
||
if (IN_SIGTRAMP (pc, (char *)NULL))
|
||
{
|
||
cache_pc_function_low = SIGTRAMP_START (pc);
|
||
cache_pc_function_high = SIGTRAMP_END (pc);
|
||
cache_pc_function_name = "<sigtramp>";
|
||
|
||
goto return_cached_value;
|
||
}
|
||
#endif
|
||
|
||
msymbol = lookup_minimal_symbol_by_pc (pc);
|
||
pst = find_pc_psymtab (pc);
|
||
if (pst)
|
||
{
|
||
/* Need to read the symbols to get a good value for the end address. */
|
||
if (endaddr != NULL && !pst->readin)
|
||
{
|
||
/* Need to get the terminal in case symbol-reading produces
|
||
output. */
|
||
target_terminal_ours_for_output ();
|
||
PSYMTAB_TO_SYMTAB (pst);
|
||
}
|
||
|
||
if (pst->readin)
|
||
{
|
||
/* Checking whether the msymbol has a larger value is for the
|
||
"pathological" case mentioned in print_frame_info. */
|
||
f = find_pc_function (pc);
|
||
if (f != NULL
|
||
&& (msymbol == NULL
|
||
|| (BLOCK_START (SYMBOL_BLOCK_VALUE (f))
|
||
>= SYMBOL_VALUE_ADDRESS (msymbol))))
|
||
{
|
||
cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
|
||
cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
|
||
cache_pc_function_name = SYMBOL_NAME (f);
|
||
goto return_cached_value;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Now that static symbols go in the minimal symbol table, perhaps
|
||
we could just ignore the partial symbols. But at least for now
|
||
we use the partial or minimal symbol, whichever is larger. */
|
||
psb = find_pc_psymbol (pst, pc);
|
||
|
||
if (psb
|
||
&& (msymbol == NULL ||
|
||
(SYMBOL_VALUE_ADDRESS (psb)
|
||
>= SYMBOL_VALUE_ADDRESS (msymbol))))
|
||
{
|
||
/* This case isn't being cached currently. */
|
||
if (address)
|
||
*address = SYMBOL_VALUE_ADDRESS (psb);
|
||
if (name)
|
||
*name = SYMBOL_NAME (psb);
|
||
/* endaddr non-NULL can't happen here. */
|
||
return 1;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Not in the normal symbol tables, see if the pc is in a known section.
|
||
If it's not, then give up. This ensures that anything beyond the end
|
||
of the text seg doesn't appear to be part of the last function in the
|
||
text segment. */
|
||
|
||
sec = find_pc_section (pc);
|
||
|
||
if (!sec)
|
||
msymbol = NULL;
|
||
|
||
/* Must be in the minimal symbol table. */
|
||
if (msymbol == NULL)
|
||
{
|
||
/* No available symbol. */
|
||
if (name != NULL)
|
||
*name = 0;
|
||
if (address != NULL)
|
||
*address = 0;
|
||
if (endaddr != NULL)
|
||
*endaddr = 0;
|
||
return 0;
|
||
}
|
||
|
||
cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol);
|
||
cache_pc_function_name = SYMBOL_NAME (msymbol);
|
||
|
||
/* Use the lesser of the next minimal symbol, or the end of the section, as
|
||
the end of the function. */
|
||
|
||
if (SYMBOL_NAME (msymbol + 1) != NULL
|
||
&& SYMBOL_VALUE_ADDRESS (msymbol + 1) < sec->endaddr)
|
||
cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + 1);
|
||
else
|
||
/* We got the start address from the last msymbol in the objfile.
|
||
So the end address is the end of the section. */
|
||
cache_pc_function_high = sec->endaddr;
|
||
|
||
return_cached_value:
|
||
if (address)
|
||
*address = cache_pc_function_low;
|
||
if (name)
|
||
*name = cache_pc_function_name;
|
||
if (endaddr)
|
||
*endaddr = cache_pc_function_high;
|
||
return 1;
|
||
}
|
||
|
||
/* Return the innermost stack frame executing inside of BLOCK,
|
||
or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
|
||
|
||
struct frame_info *
|
||
block_innermost_frame (block)
|
||
struct block *block;
|
||
{
|
||
struct frame_info *frame;
|
||
register CORE_ADDR start;
|
||
register CORE_ADDR end;
|
||
|
||
if (block == NULL)
|
||
return NULL;
|
||
|
||
start = BLOCK_START (block);
|
||
end = BLOCK_END (block);
|
||
|
||
frame = NULL;
|
||
while (1)
|
||
{
|
||
frame = get_prev_frame (frame);
|
||
if (frame == NULL)
|
||
return NULL;
|
||
if (frame->pc >= start && frame->pc < end)
|
||
return frame;
|
||
}
|
||
}
|
||
|
||
/* Return the full FRAME which corresponds to the given CORE_ADDR
|
||
or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
|
||
|
||
struct frame_info *
|
||
find_frame_addr_in_frame_chain (frame_addr)
|
||
CORE_ADDR frame_addr;
|
||
{
|
||
struct frame_info *frame = NULL;
|
||
|
||
if (frame_addr == (CORE_ADDR)0)
|
||
return NULL;
|
||
|
||
while (1)
|
||
{
|
||
frame = get_prev_frame (frame);
|
||
if (frame == NULL)
|
||
return NULL;
|
||
if (FRAME_FP (frame) == frame_addr)
|
||
return frame;
|
||
}
|
||
}
|
||
|
||
#ifdef SIGCONTEXT_PC_OFFSET
|
||
/* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
|
||
|
||
CORE_ADDR
|
||
sigtramp_saved_pc (frame)
|
||
struct frame_info *frame;
|
||
{
|
||
CORE_ADDR sigcontext_addr;
|
||
char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
|
||
int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
|
||
int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
|
||
|
||
/* Get sigcontext address, it is the third parameter on the stack. */
|
||
if (frame->next)
|
||
sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next)
|
||
+ FRAME_ARGS_SKIP
|
||
+ sigcontext_offs,
|
||
ptrbytes);
|
||
else
|
||
sigcontext_addr = read_memory_integer (read_register (SP_REGNUM)
|
||
+ sigcontext_offs,
|
||
ptrbytes);
|
||
|
||
/* Don't cause a memory_error when accessing sigcontext in case the stack
|
||
layout has changed or the stack is corrupt. */
|
||
target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
|
||
return extract_unsigned_integer (buf, ptrbytes);
|
||
}
|
||
#endif /* SIGCONTEXT_PC_OFFSET */
|
||
|
||
#ifdef USE_GENERIC_DUMMY_FRAMES
|
||
|
||
/*
|
||
* GENERIC DUMMY FRAMES
|
||
*
|
||
* The following code serves to maintain the dummy stack frames for
|
||
* inferior function calls (ie. when gdb calls into the inferior via
|
||
* call_function_by_hand). This code saves the machine state before
|
||
* the call in host memory, so we must maintain an independant stack
|
||
* and keep it consistant etc. I am attempting to make this code
|
||
* generic enough to be used by many targets.
|
||
*
|
||
* The cheapest and most generic way to do CALL_DUMMY on a new target
|
||
* is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to zero,
|
||
* and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember to define
|
||
* PUSH_RETURN_ADDRESS, because no call instruction will be being
|
||
* executed by the target.
|
||
*/
|
||
|
||
static struct dummy_frame *dummy_frame_stack = NULL;
|
||
|
||
/* Function: find_dummy_frame(pc, fp, sp)
|
||
Search the stack of dummy frames for one matching the given PC, FP and SP.
|
||
This is the work-horse for pc_in_call_dummy and read_register_dummy */
|
||
|
||
char *
|
||
generic_find_dummy_frame (pc, fp)
|
||
CORE_ADDR pc;
|
||
CORE_ADDR fp;
|
||
{
|
||
struct dummy_frame * dummyframe;
|
||
|
||
if (pc != entry_point_address ())
|
||
return 0;
|
||
|
||
for (dummyframe = dummy_frame_stack; dummyframe != NULL;
|
||
dummyframe = dummyframe->next)
|
||
if (fp == dummyframe->fp || fp == dummyframe->sp)
|
||
/* The frame in question lies between the saved fp and sp, inclusive */
|
||
return dummyframe->regs;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Function: pc_in_call_dummy (pc, fp)
|
||
Return true if this is a dummy frame created by gdb for an inferior call */
|
||
|
||
int
|
||
generic_pc_in_call_dummy (pc, fp)
|
||
CORE_ADDR pc;
|
||
CORE_ADDR fp;
|
||
{
|
||
/* if find_dummy_frame succeeds, then PC is in a call dummy */
|
||
return (generic_find_dummy_frame (pc, fp) != 0);
|
||
}
|
||
|
||
/* Function: read_register_dummy
|
||
Find a saved register from before GDB calls a function in the inferior */
|
||
|
||
CORE_ADDR
|
||
generic_read_register_dummy (pc, fp, regno)
|
||
CORE_ADDR pc;
|
||
CORE_ADDR fp;
|
||
int regno;
|
||
{
|
||
char *dummy_regs = generic_find_dummy_frame (pc, fp);
|
||
|
||
if (dummy_regs)
|
||
return extract_address (&dummy_regs[REGISTER_BYTE (regno)],
|
||
REGISTER_RAW_SIZE(regno));
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
/* Save all the registers on the dummy frame stack. Most ports save the
|
||
registers on the target stack. This results in lots of unnecessary memory
|
||
references, which are slow when debugging via a serial line. Instead, we
|
||
save all the registers internally, and never write them to the stack. The
|
||
registers get restored when the called function returns to the entry point,
|
||
where a breakpoint is laying in wait. */
|
||
|
||
void
|
||
generic_push_dummy_frame ()
|
||
{
|
||
struct dummy_frame *dummy_frame;
|
||
CORE_ADDR fp = (get_current_frame ())->frame;
|
||
|
||
/* check to see if there are stale dummy frames,
|
||
perhaps left over from when a longjump took us out of a
|
||
function that was called by the debugger */
|
||
|
||
dummy_frame = dummy_frame_stack;
|
||
while (dummy_frame)
|
||
if (dummy_frame->fp INNER_THAN fp) /* stale -- destroy! */
|
||
{
|
||
dummy_frame_stack = dummy_frame->next;
|
||
free (dummy_frame);
|
||
dummy_frame = dummy_frame_stack;
|
||
}
|
||
else
|
||
dummy_frame = dummy_frame->next;
|
||
|
||
dummy_frame = xmalloc (sizeof (struct dummy_frame));
|
||
dummy_frame->pc = read_register (PC_REGNUM);
|
||
dummy_frame->sp = read_register (SP_REGNUM);
|
||
dummy_frame->fp = fp;
|
||
read_register_bytes (0, dummy_frame->regs, REGISTER_BYTES);
|
||
dummy_frame->next = dummy_frame_stack;
|
||
dummy_frame_stack = dummy_frame;
|
||
}
|
||
|
||
/* Function: pop_dummy_frame
|
||
Restore the machine state from a saved dummy stack frame. */
|
||
|
||
void
|
||
generic_pop_dummy_frame ()
|
||
{
|
||
struct dummy_frame *dummy_frame = dummy_frame_stack;
|
||
|
||
/* FIXME: what if the first frame isn't the right one, eg..
|
||
because one call-by-hand function has done a longjmp into another one? */
|
||
|
||
if (!dummy_frame)
|
||
error ("Can't pop dummy frame!");
|
||
dummy_frame_stack = dummy_frame->next;
|
||
write_register_bytes (0, dummy_frame->regs, REGISTER_BYTES);
|
||
free (dummy_frame);
|
||
}
|
||
|
||
/* Function: frame_chain_valid
|
||
Returns true for a user frame or a call_function_by_hand dummy frame,
|
||
and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
|
||
|
||
int
|
||
generic_frame_chain_valid (fp, fi)
|
||
CORE_ADDR fp;
|
||
struct frame_info *fi;
|
||
{
|
||
if (PC_IN_CALL_DUMMY(FRAME_SAVED_PC(fi), fp, fp))
|
||
return 1; /* don't prune CALL_DUMMY frames */
|
||
else /* fall back to default algorithm (see frame.h) */
|
||
return (fp != 0
|
||
&& fi->frame INNER_THAN fp
|
||
&& !inside_entry_file (FRAME_SAVED_PC(fi)));
|
||
}
|
||
|
||
/* Function: get_saved_register
|
||
Find register number REGNUM relative to FRAME and put its (raw,
|
||
target format) contents in *RAW_BUFFER.
|
||
|
||
Set *OPTIMIZED if the variable was optimized out (and thus can't be
|
||
fetched). Note that this is never set to anything other than zero
|
||
in this implementation.
|
||
|
||
Set *LVAL to lval_memory, lval_register, or not_lval, depending on
|
||
whether the value was fetched from memory, from a register, or in a
|
||
strange and non-modifiable way (e.g. a frame pointer which was
|
||
calculated rather than fetched). We will use not_lval for values
|
||
fetched from generic dummy frames.
|
||
|
||
Set *ADDRP to the address, either in memory on as a REGISTER_BYTE
|
||
offset into the registers array. If the value is stored in a dummy
|
||
frame, set *ADDRP to zero.
|
||
|
||
To use this implementation, define a function called
|
||
"get_saved_register" in your target code, which simply passes all
|
||
of its arguments to this function.
|
||
|
||
The argument RAW_BUFFER must point to aligned memory. */
|
||
|
||
void
|
||
generic_get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval)
|
||
char *raw_buffer;
|
||
int *optimized;
|
||
CORE_ADDR *addrp;
|
||
struct frame_info *frame;
|
||
int regnum;
|
||
enum lval_type *lval;
|
||
{
|
||
CORE_ADDR addr;
|
||
struct frame_saved_regs fsr;
|
||
|
||
if (!target_has_registers)
|
||
error ("No registers.");
|
||
|
||
/* Normal systems don't optimize out things with register numbers. */
|
||
if (optimized != NULL)
|
||
*optimized = 0;
|
||
|
||
if (addrp) /* default assumption: not found in memory */
|
||
*addrp = 0;
|
||
|
||
/* Note: since the current frame's registers could only have been
|
||
saved by frames INTERIOR TO the current frame, we skip examining
|
||
the current frame itself: otherwise, we would be getting the
|
||
previous frame's registers which were saved by the current frame. */
|
||
|
||
while (frame && ((frame = frame->next) != NULL))
|
||
{
|
||
if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
|
||
{
|
||
if (lval) /* found it in a CALL_DUMMY frame */
|
||
*lval = not_lval;
|
||
if (raw_buffer)
|
||
memcpy (raw_buffer,
|
||
generic_find_dummy_frame (frame->pc, frame->frame) +
|
||
REGISTER_BYTE (regnum),
|
||
REGISTER_RAW_SIZE (regnum));
|
||
return;
|
||
}
|
||
|
||
FRAME_FIND_SAVED_REGS(frame, fsr);
|
||
if (fsr.regs[regnum] != 0)
|
||
{
|
||
if (lval) /* found it saved on the stack */
|
||
*lval = lval_memory;
|
||
if (regnum == SP_REGNUM)
|
||
{
|
||
if (raw_buffer) /* SP register treated specially */
|
||
store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
|
||
fsr.regs[regnum]);
|
||
}
|
||
else
|
||
{
|
||
if (addrp) /* any other register */
|
||
*addrp = fsr.regs[regnum];
|
||
if (raw_buffer)
|
||
read_memory (fsr.regs[regnum], raw_buffer,
|
||
REGISTER_RAW_SIZE (regnum));
|
||
}
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* If we get thru the loop to this point, it means the register was
|
||
not saved in any frame. Return the actual live-register value. */
|
||
|
||
if (lval) /* found it in a live register */
|
||
*lval = lval_register;
|
||
if (addrp)
|
||
*addrp = REGISTER_BYTE (regnum);
|
||
if (raw_buffer)
|
||
read_register_gen (regnum, raw_buffer);
|
||
}
|
||
#endif /* USE_GENERIC_DUMMY_FRAMES */
|
||
|
||
void
|
||
_initialize_blockframe ()
|
||
{
|
||
obstack_init (&frame_cache_obstack);
|
||
}
|