669 lines
18 KiB
C
669 lines
18 KiB
C
/* Get info from stack frames;
|
||
convert between frames, blocks, functions and pc values.
|
||
Copyright (C) 1986, 1987, 1988, 1989 Free Software Foundation, Inc.
|
||
|
||
This file is part of GDB.
|
||
|
||
This program is free software; you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 2 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program; if not, write to the Free Software
|
||
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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||
|
||
#include <stdio.h>
|
||
#include "defs.h"
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#include "param.h"
|
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#include "symtab.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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/* Required by INIT_EXTRA_FRAME_INFO on 88k. */
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#include <setjmp.h>
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#include <obstack.h>
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|
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CORE_ADDR read_pc (); /* In infcmd.c */
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/* Start and end of object file containing the entry point.
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STARTUP_FILE_END is the first address of the next file.
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This file is assumed to be a startup file
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and frames with pc's inside it
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are treated as nonexistent.
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||
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||
Setting these variables is necessary so that backtraces do not fly off
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the bottom of the stack. */
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CORE_ADDR startup_file_start;
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||
CORE_ADDR startup_file_end;
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||
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/* Is ADDR outside 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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int
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||
outside_startup_file (addr)
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CORE_ADDR addr;
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{
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return !(addr >= startup_file_start && addr < startup_file_end);
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}
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/* Address of innermost stack frame (contents of FP register) */
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||
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static FRAME current_frame;
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||
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/*
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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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*/
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struct obstack frame_cache_obstack;
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/* Return the innermost (currently executing) stack frame. */
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FRAME
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get_current_frame ()
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{
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/* We assume its address is kept in a general register;
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param.h says which register. */
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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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FRAME frame;
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{
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current_frame = frame;
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}
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FRAME
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create_new_frame (addr, pc)
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FRAME_ADDR addr;
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CORE_ADDR pc;
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{
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struct frame_info *fci; /* Same type as FRAME */
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fci = (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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fci->next = (struct frame_info *) 0;
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fci->prev = (struct frame_info *) 0;
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fci->frame = addr;
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fci->next_frame = 0; /* Since arbitrary */
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fci->pc = pc;
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#ifdef INIT_EXTRA_FRAME_INFO
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INIT_EXTRA_FRAME_INFO (fci);
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#endif
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return fci;
|
||
}
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/* Return the frame that called FRAME.
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If FRAME is the original frame (it has no caller), return 0. */
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FRAME
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get_prev_frame (frame)
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FRAME frame;
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{
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||
/* We're allowed to know that FRAME and "struct frame_info *" are
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the same */
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return get_prev_frame_info (frame);
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}
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||
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/* Return the frame that FRAME calls (0 if FRAME is the innermost
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frame). */
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||
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FRAME
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get_next_frame (frame)
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FRAME frame;
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{
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||
/* We're allowed to know that FRAME and "struct frame_info *" are
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the same */
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return frame->next;
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}
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/*
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* Flush the entire frame cache.
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*/
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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 = (struct frame_info *) 0; /* Invalidate cache */
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}
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/* Flush the frame cache, and start a new one if necessary. */
|
||
void
|
||
reinit_frame_cache ()
|
||
{
|
||
FRAME fr = current_frame;
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||
flush_cached_frames ();
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||
if (fr)
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||
set_current_frame ( create_new_frame (read_register (FP_REGNUM),
|
||
read_pc ()));
|
||
}
|
||
|
||
/* Return a structure containing various interesting information
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about a specified stack frame. */
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/* How do I justify including this function? Well, the FRAME
|
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identifier format has gone through several changes recently, and
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it's not completely inconceivable that it could happen again. If
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it does, have this routine around will help */
|
||
|
||
struct frame_info *
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get_frame_info (frame)
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FRAME frame;
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||
{
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return frame;
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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
|
||
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 has 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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||
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int
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frameless_look_for_prologue (frame)
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||
FRAME 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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||
FUNCTION_START_OFFSET);
|
||
if (func_start)
|
||
{
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||
after_prologue = func_start;
|
||
#ifdef SKIP_PROLOGUE_FRAMELESS_P
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/* This is faster, since only care whether there *is* a prologue,
|
||
not how long it is. */
|
||
SKIP_PROLOGUE_FRAMELESS_P (after_prologue);
|
||
#else
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||
SKIP_PROLOGUE (after_prologue);
|
||
#endif
|
||
return after_prologue == func_start;
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||
}
|
||
else
|
||
/* 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
|
||
circumstances) backtrace by saying that it isn't. */
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||
return 0;
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||
}
|
||
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||
#if !defined (INIT_FRAME_PC)
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||
#define INIT_FRAME_PC(fromleaf, prev) \
|
||
prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
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||
prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
|
||
#endif
|
||
|
||
/* Return a structure containing various interesting information
|
||
about the frame that called NEXT_FRAME. Returns NULL
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||
if there is no such frame. */
|
||
|
||
struct frame_info *
|
||
get_prev_frame_info (next_frame)
|
||
FRAME next_frame;
|
||
{
|
||
FRAME_ADDR address;
|
||
struct frame_info *prev;
|
||
int fromleaf = 0;
|
||
|
||
/* If the requested entry is in the cache, return it.
|
||
Otherwise, figure out what the address should be for the entry
|
||
we're about to add to the cache. */
|
||
|
||
if (!next_frame)
|
||
{
|
||
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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return current_frame;
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||
}
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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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||
FRAMELESS_FUNCTION_INVOCATION (next_frame, fromleaf);
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||
if (fromleaf)
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||
address = next_frame->frame;
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||
}
|
||
#endif
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||
|
||
if (!fromleaf)
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||
{
|
||
/* Two macros defined in tm.h specify the machine-dependent
|
||
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
|
||
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
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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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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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if (next_frame)
|
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next_frame->prev = prev;
|
||
prev->next = next_frame;
|
||
prev->prev = (struct frame_info *) 0;
|
||
prev->frame = address;
|
||
prev->next_frame = prev->next ? prev->next->frame : 0;
|
||
|
||
#ifdef INIT_EXTRA_FRAME_INFO
|
||
INIT_EXTRA_FRAME_INFO(prev);
|
||
#endif
|
||
|
||
/* This entry is in the frame queue now, which is good since
|
||
FRAME_SAVED_PC may use that queue to figure out it's value
|
||
(see m-sparc.h). We want the pc saved in the inferior frame. */
|
||
INIT_FRAME_PC(fromleaf, prev);
|
||
|
||
return prev;
|
||
}
|
||
|
||
CORE_ADDR
|
||
get_frame_pc (frame)
|
||
FRAME frame;
|
||
{
|
||
struct frame_info *fi;
|
||
fi = get_frame_info (frame);
|
||
return fi->pc;
|
||
}
|
||
|
||
#if defined (FRAME_FIND_SAVED_REGS)
|
||
/* Find the addresses in which registers are saved in FRAME. */
|
||
|
||
void
|
||
get_frame_saved_regs (frame_info_addr, saved_regs_addr)
|
||
struct frame_info *frame_info_addr;
|
||
struct frame_saved_regs *saved_regs_addr;
|
||
{
|
||
FRAME_FIND_SAVED_REGS (frame_info_addr, *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)
|
||
FRAME frame;
|
||
{
|
||
struct frame_info *fi;
|
||
CORE_ADDR pc;
|
||
|
||
fi = get_frame_info (frame);
|
||
|
||
pc = fi->pc;
|
||
if (fi->next_frame != 0)
|
||
/* We are not in the innermost frame. 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 fi->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 = block_for_pc (pc);
|
||
register struct symbol *symbol;
|
||
if (bl == 0 || (symbol = block_function (bl)) == 0)
|
||
{
|
||
register int misc_index = find_pc_misc_function (pc);
|
||
if (misc_index >= 0)
|
||
return misc_function_vector[misc_index].address;
|
||
return 0;
|
||
}
|
||
bl = SYMBOL_BLOCK_VALUE (symbol);
|
||
return BLOCK_START (bl);
|
||
}
|
||
|
||
/* Return the symbol for the function executing in frame FRAME. */
|
||
|
||
struct symbol *
|
||
get_frame_function (frame)
|
||
FRAME 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-zero.
|
||
Returns 0 if it couldn't find anything, 1 if it did. On a zero
|
||
return, *NAME and *ADDRESS are always set to zero. On a 1 return,
|
||
*NAME and *ADDRESS contain real information. */
|
||
|
||
int
|
||
find_pc_partial_function (pc, name, address)
|
||
CORE_ADDR pc;
|
||
char **name;
|
||
CORE_ADDR *address;
|
||
{
|
||
struct partial_symtab *pst;
|
||
struct symbol *f;
|
||
int miscfunc;
|
||
struct partial_symbol *psb;
|
||
|
||
if (pc >= cache_pc_function_low && pc < cache_pc_function_high)
|
||
{
|
||
if (address)
|
||
*address = cache_pc_function_low;
|
||
if (name)
|
||
*name = cache_pc_function_name;
|
||
return 1;
|
||
}
|
||
|
||
pst = find_pc_psymtab (pc);
|
||
if (pst)
|
||
{
|
||
if (pst->readin)
|
||
{
|
||
/* The information we want has already been read in.
|
||
We can go to the already readin symbols and we'll get
|
||
the best possible answer. */
|
||
f = find_pc_function (pc);
|
||
if (!f)
|
||
{
|
||
return_error:
|
||
/* No available symbol. */
|
||
if (name != 0)
|
||
*name = 0;
|
||
if (address != 0)
|
||
*address = 0;
|
||
return 0;
|
||
}
|
||
|
||
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);
|
||
if (name)
|
||
*name = cache_pc_function_name;
|
||
if (address)
|
||
*address = cache_pc_function_low;
|
||
return 1;
|
||
}
|
||
|
||
/* Get the information from a combination of the pst
|
||
(static symbols), and the misc function vector (extern
|
||
symbols). */
|
||
miscfunc = find_pc_misc_function (pc);
|
||
psb = find_pc_psymbol (pst, pc);
|
||
|
||
if (!psb && miscfunc == -1)
|
||
{
|
||
goto return_error;
|
||
}
|
||
if (psb
|
||
&& (miscfunc == -1
|
||
|| (SYMBOL_VALUE_ADDRESS (psb)
|
||
>= misc_function_vector[miscfunc].address)))
|
||
{
|
||
/* This case isn't being cached currently. */
|
||
if (address)
|
||
*address = SYMBOL_VALUE_ADDRESS (psb);
|
||
if (name)
|
||
*name = SYMBOL_NAME (psb);
|
||
return 1;
|
||
}
|
||
}
|
||
else
|
||
/* Must be in the misc function stuff. */
|
||
{
|
||
miscfunc = find_pc_misc_function (pc);
|
||
if (miscfunc == -1)
|
||
goto return_error;
|
||
}
|
||
|
||
{
|
||
if (misc_function_vector[miscfunc].type == mf_text)
|
||
cache_pc_function_low = misc_function_vector[miscfunc].address;
|
||
else
|
||
/* It is a transfer table for Sun shared libraries. */
|
||
cache_pc_function_low = pc - FUNCTION_START_OFFSET;
|
||
}
|
||
cache_pc_function_name = misc_function_vector[miscfunc].name;
|
||
if (miscfunc < misc_function_count /* && FIXME mf_text again? */ )
|
||
cache_pc_function_high = misc_function_vector[miscfunc+1].address;
|
||
else
|
||
cache_pc_function_high = cache_pc_function_low + 1;
|
||
if (address)
|
||
*address = cache_pc_function_low;
|
||
if (name)
|
||
*name = cache_pc_function_name;
|
||
return 1;
|
||
}
|
||
|
||
/* Find the misc function whose address is the largest
|
||
while being less than PC. Return its index in misc_function_vector.
|
||
Returns -1 if PC is not in suitable range. */
|
||
|
||
int
|
||
find_pc_misc_function (pc)
|
||
register CORE_ADDR pc;
|
||
{
|
||
register int lo = 0;
|
||
register int hi = misc_function_count-1;
|
||
register int new;
|
||
|
||
/* Note that the last thing in the vector is always _etext. */
|
||
/* Actually, "end", now that non-functions
|
||
go on the misc_function_vector. */
|
||
|
||
/* Above statement is not *always* true - fix for case where there are */
|
||
/* no misc functions at all (ie no symbol table has been read). */
|
||
if (hi < 0) return -1; /* no misc functions recorded */
|
||
|
||
/* trivial reject range test */
|
||
if (pc < misc_function_vector[0].address ||
|
||
pc > misc_function_vector[hi].address)
|
||
return -1;
|
||
|
||
/* Note that the following search will not return hi if
|
||
pc == misc_function_vector[hi].address. If "end" points to the
|
||
first unused location, this is correct and the above test
|
||
simply needs to be changed to
|
||
"pc >= misc_function_vector[hi].address". */
|
||
do {
|
||
new = (lo + hi) >> 1;
|
||
if (misc_function_vector[new].address == pc)
|
||
return new; /* an exact match */
|
||
else if (misc_function_vector[new].address > pc)
|
||
hi = new;
|
||
else
|
||
lo = new;
|
||
} while (hi-lo != 1);
|
||
|
||
/* if here, we had no exact match, so return the lower choice */
|
||
return lo;
|
||
}
|
||
|
||
/* Return the innermost stack frame executing inside of the specified block,
|
||
or zero if there is no such frame. */
|
||
|
||
FRAME
|
||
block_innermost_frame (block)
|
||
struct block *block;
|
||
{
|
||
struct frame_info *fi;
|
||
register FRAME frame;
|
||
register CORE_ADDR start = BLOCK_START (block);
|
||
register CORE_ADDR end = BLOCK_END (block);
|
||
|
||
frame = 0;
|
||
while (1)
|
||
{
|
||
frame = get_prev_frame (frame);
|
||
if (frame == 0)
|
||
return 0;
|
||
fi = get_frame_info (frame);
|
||
if (fi->pc >= start && fi->pc < end)
|
||
return frame;
|
||
}
|
||
}
|
||
|
||
void
|
||
_initialize_blockframe ()
|
||
{
|
||
obstack_init (&frame_cache_obstack);
|
||
}
|