| /* Cache and manage the values of registers for GDB, the GNU debugger. |
| |
| Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, |
| 2001, 2002 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., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "defs.h" |
| #include "frame.h" |
| #include "target.h" |
| #include "value.h" |
| #include "inferior.h" /* for inferior_ptid */ |
| #include "regcache.h" |
| |
| /* FIND_SAVED_REGISTER () |
| |
| Return the address in which frame FRAME's value of register REGNUM |
| has been saved in memory. Or return zero if it has not been saved. |
| If REGNUM specifies the SP, the value we return is actually |
| the SP value, not an address where it was saved. */ |
| |
| CORE_ADDR |
| find_saved_register (struct frame_info *frame, int regnum) |
| { |
| register struct frame_info *frame1 = NULL; |
| register CORE_ADDR addr = 0; |
| |
| if (frame == NULL) /* No regs saved if want current frame */ |
| return 0; |
| |
| /* Note that this next routine assumes that registers used in |
| frame x will be saved only in the frame that x calls and |
| frames interior to it. This is not true on the sparc, but the |
| above macro takes care of it, so we should be all right. */ |
| while (1) |
| { |
| QUIT; |
| frame1 = get_next_frame (frame); |
| if (frame1 == 0) |
| break; |
| frame = frame1; |
| FRAME_INIT_SAVED_REGS (frame1); |
| if (frame1->saved_regs[regnum]) |
| addr = frame1->saved_regs[regnum]; |
| } |
| |
| return addr; |
| } |
| |
| /* DEFAULT_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). 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). Set *ADDRP to the address, either in memory |
| on as a REGISTER_BYTE offset into the registers array. |
| |
| Note that this implementation never sets *LVAL to not_lval. But |
| it can be replaced by defining GET_SAVED_REGISTER and supplying |
| your own. |
| |
| The argument RAW_BUFFER must point to aligned memory. */ |
| |
| static void |
| default_get_saved_register (char *raw_buffer, |
| int *optimized, |
| CORE_ADDR *addrp, |
| struct frame_info *frame, |
| int regnum, |
| enum lval_type *lval) |
| { |
| CORE_ADDR addr; |
| |
| if (!target_has_registers) |
| error ("No registers."); |
| |
| /* Normal systems don't optimize out things with register numbers. */ |
| if (optimized != NULL) |
| *optimized = 0; |
| addr = find_saved_register (frame, regnum); |
| if (addr != 0) |
| { |
| if (lval != NULL) |
| *lval = lval_memory; |
| if (regnum == SP_REGNUM) |
| { |
| if (raw_buffer != NULL) |
| { |
| /* Put it back in target format. */ |
| store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), |
| (LONGEST) addr); |
| } |
| if (addrp != NULL) |
| *addrp = 0; |
| return; |
| } |
| if (raw_buffer != NULL) |
| target_read_memory (addr, raw_buffer, REGISTER_RAW_SIZE (regnum)); |
| } |
| else |
| { |
| if (lval != NULL) |
| *lval = lval_register; |
| addr = REGISTER_BYTE (regnum); |
| if (raw_buffer != NULL) |
| read_register_gen (regnum, raw_buffer); |
| } |
| if (addrp != NULL) |
| *addrp = addr; |
| } |
| |
| #if !defined (GET_SAVED_REGISTER) |
| #define GET_SAVED_REGISTER(raw_buffer, optimized, addrp, frame, regnum, lval) \ |
| default_get_saved_register(raw_buffer, optimized, addrp, frame, regnum, lval) |
| #endif |
| |
| void |
| get_saved_register (char *raw_buffer, |
| int *optimized, |
| CORE_ADDR *addrp, |
| struct frame_info *frame, |
| int regnum, |
| enum lval_type *lval) |
| { |
| GET_SAVED_REGISTER (raw_buffer, optimized, addrp, frame, regnum, lval); |
| } |
| |
| /* frame_register_read () |
| |
| Find and return the value of REGNUM for the specified stack frame. |
| The number of bytes copied is REGISTER_RAW_SIZE (REGNUM). |
| |
| Returns 0 if the register value could not be found. */ |
| |
| int |
| frame_register_read (struct frame_info *frame, int regnum, void *myaddr) |
| { |
| int optim; |
| get_saved_register (myaddr, &optim, (CORE_ADDR *) NULL, frame, |
| regnum, (enum lval_type *) NULL); |
| |
| /* FIXME: cagney/2002-04-10: This test is just bogus. It is no |
| indication of the validity of the register. The value could |
| easily be found (on the stack) even though the corresponding |
| register isn't available. */ |
| if (register_cached (regnum) < 0) |
| return 0; /* register value not available */ |
| |
| return !optim; |
| } |