225 lines
7 KiB
C
225 lines
7 KiB
C
/* Cache and manage the values of registers for GDB, the GNU debugger.
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Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, 2001
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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,
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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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/* FIND_SAVED_REGISTER ()
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Return the address in which frame FRAME's value of register REGNUM
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has been saved in memory. Or return zero if it has not been saved.
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If REGNUM specifies the SP, the value we return is actually
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the SP value, not an address where it was saved. */
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CORE_ADDR
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find_saved_register (struct frame_info *frame, int regnum)
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{
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register struct frame_info *frame1 = NULL;
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register CORE_ADDR addr = 0;
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if (frame == NULL) /* No regs saved if want current frame */
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return 0;
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#ifdef HAVE_REGISTER_WINDOWS
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/* We assume that a register in a register window will only be saved
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in one place (since the name changes and/or disappears as you go
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towards inner frames), so we only call get_frame_saved_regs on
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the current frame. This is directly in contradiction to the
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usage below, which assumes that registers used in a frame must be
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saved in a lower (more interior) frame. This change is a result
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of working on a register window machine; get_frame_saved_regs
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always returns the registers saved within a frame, within the
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context (register namespace) of that frame. */
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/* However, note that we don't want this to return anything if
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nothing is saved (if there's a frame inside of this one). Also,
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callers to this routine asking for the stack pointer want the
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stack pointer saved for *this* frame; this is returned from the
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next frame. */
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if (REGISTER_IN_WINDOW_P (regnum))
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{
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frame1 = get_next_frame (frame);
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if (!frame1)
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return 0; /* Registers of this frame are active. */
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/* Get the SP from the next frame in; it will be this
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current frame. */
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if (regnum != SP_REGNUM)
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frame1 = frame;
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FRAME_INIT_SAVED_REGS (frame1);
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return frame1->saved_regs[regnum]; /* ... which might be zero */
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}
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#endif /* HAVE_REGISTER_WINDOWS */
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/* Note that this next routine assumes that registers used in
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frame x will be saved only in the frame that x calls and
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frames interior to it. This is not true on the sparc, but the
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above macro takes care of it, so we should be all right. */
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while (1)
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{
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QUIT;
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frame1 = get_prev_frame (frame1);
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if (frame1 == 0 || frame1 == frame)
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break;
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FRAME_INIT_SAVED_REGS (frame1);
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if (frame1->saved_regs[regnum])
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addr = frame1->saved_regs[regnum];
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}
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return addr;
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}
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/* DEFAULT_GET_SAVED_REGISTER ()
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Find register number REGNUM relative to FRAME and put its (raw,
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target format) contents in *RAW_BUFFER. Set *OPTIMIZED if the
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variable was optimized out (and thus can't be fetched). Set *LVAL
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to lval_memory, lval_register, or not_lval, depending on whether
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the value was fetched from memory, from a register, or in a strange
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and non-modifiable way (e.g. a frame pointer which was calculated
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rather than fetched). Set *ADDRP to the address, either in memory
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on as a REGISTER_BYTE offset into the registers array.
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Note that this implementation never sets *LVAL to not_lval. But
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it can be replaced by defining GET_SAVED_REGISTER and supplying
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your own.
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The argument RAW_BUFFER must point to aligned memory. */
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static void
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default_get_saved_register (char *raw_buffer,
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int *optimized,
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CORE_ADDR *addrp,
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struct frame_info *frame,
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int regnum,
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enum lval_type *lval)
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{
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CORE_ADDR addr;
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if (!target_has_registers)
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error ("No registers.");
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/* Normal systems don't optimize out things with register numbers. */
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if (optimized != NULL)
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*optimized = 0;
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addr = find_saved_register (frame, regnum);
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if (addr != 0)
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{
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if (lval != NULL)
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*lval = lval_memory;
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if (regnum == SP_REGNUM)
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{
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if (raw_buffer != NULL)
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{
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/* Put it back in target format. */
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store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
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(LONGEST) addr);
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}
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if (addrp != NULL)
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*addrp = 0;
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return;
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}
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if (raw_buffer != NULL)
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target_read_memory (addr, raw_buffer, REGISTER_RAW_SIZE (regnum));
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}
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else
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{
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if (lval != NULL)
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*lval = lval_register;
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addr = REGISTER_BYTE (regnum);
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if (raw_buffer != NULL)
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read_register_gen (regnum, raw_buffer);
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}
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if (addrp != NULL)
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*addrp = addr;
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}
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#if !defined (GET_SAVED_REGISTER)
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#define GET_SAVED_REGISTER(raw_buffer, optimized, addrp, frame, regnum, lval) \
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default_get_saved_register(raw_buffer, optimized, addrp, frame, regnum, lval)
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#endif
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void
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get_saved_register (char *raw_buffer,
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int *optimized,
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CORE_ADDR *addrp,
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struct frame_info *frame,
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int regnum,
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enum lval_type *lval)
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{
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GET_SAVED_REGISTER (raw_buffer, optimized, addrp, frame, regnum, lval);
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}
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/* READ_RELATIVE_REGISTER_RAW_BYTES_FOR_FRAME
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Copy the bytes of register REGNUM, relative to the input stack frame,
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into our memory at MYADDR, in target byte order.
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The number of bytes copied is REGISTER_RAW_SIZE (REGNUM).
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Returns 1 if could not be read, 0 if could. */
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/* FIXME: This function increases the confusion between FP_REGNUM
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and the virtual/pseudo-frame pointer. */
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static int
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read_relative_register_raw_bytes_for_frame (int regnum,
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char *myaddr,
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struct frame_info *frame)
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{
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int optim;
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if (regnum == FP_REGNUM && frame)
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{
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/* Put it back in target format. */
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store_address (myaddr, REGISTER_RAW_SIZE (FP_REGNUM),
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(LONGEST) FRAME_FP (frame));
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return 0;
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}
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get_saved_register (myaddr, &optim, (CORE_ADDR *) NULL, frame,
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regnum, (enum lval_type *) NULL);
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if (register_cached (regnum) < 0)
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return 1; /* register value not available */
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return optim;
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}
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/* READ_RELATIVE_REGISTER_RAW_BYTES
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Copy the bytes of register REGNUM, relative to the current stack
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frame, into our memory at MYADDR, in target byte order.
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The number of bytes copied is REGISTER_RAW_SIZE (REGNUM).
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Returns 1 if could not be read, 0 if could. */
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int
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read_relative_register_raw_bytes (int regnum, char *myaddr)
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{
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return read_relative_register_raw_bytes_for_frame (regnum, myaddr,
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selected_frame);
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}
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