1061 lines
34 KiB
C
1061 lines
34 KiB
C
/* Target-dependent code for the MIPS architecture, for GDB, the GNU Debugger.
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Copyright 1988, 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
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Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
|
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and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
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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., 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "defs.h"
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#include "frame.h"
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#include "inferior.h"
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#include "symtab.h"
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#include "value.h"
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#include "gdbcmd.h"
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#include "language.h"
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#include "gdbcore.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "opcode/mips.h"
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#define VM_MIN_ADDRESS (unsigned)0x400000
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#if 0
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static int mips_in_lenient_prologue PARAMS ((CORE_ADDR, CORE_ADDR));
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#endif
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/* Some MIPS boards don't support floating point, so we permit the
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user to turn it off. */
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int mips_fpu = 1;
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/* Heuristic_proc_start may hunt through the text section for a long
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time across a 2400 baud serial line. Allows the user to limit this
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search. */
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static unsigned int heuristic_fence_post = 0;
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#define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */
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#define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */
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#define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset)
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#define PROC_FRAME_REG(proc) ((proc)->pdr.framereg)
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#define PROC_REG_MASK(proc) ((proc)->pdr.regmask)
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#define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask)
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#define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset)
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#define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset)
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#define PROC_PC_REG(proc) ((proc)->pdr.pcreg)
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#define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym)
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#define _PROC_MAGIC_ 0x0F0F0F0F
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#define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_)
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#define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_)
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struct linked_proc_info
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{
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struct mips_extra_func_info info;
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struct linked_proc_info *next;
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} *linked_proc_desc_table = NULL;
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#define READ_FRAME_REG(fi, regno) read_next_frame_reg((fi)->next, regno)
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static int
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read_next_frame_reg(fi, regno)
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FRAME fi;
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int regno;
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{
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/* If it is the frame for sigtramp we have a complete sigcontext
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immediately below the frame and we get the saved registers from there.
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If the stack layout for sigtramp changes we might have to change these
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constants and the companion fixup_sigtramp in mdebugread.c */
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#ifndef SIGFRAME_BASE
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#define SIGFRAME_BASE 0x12c /* sizeof(sigcontext) */
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#define SIGFRAME_PC_OFF (-SIGFRAME_BASE + 2 * 4)
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#define SIGFRAME_REGSAVE_OFF (-SIGFRAME_BASE + 3 * 4)
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#endif
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#ifndef SIGFRAME_REG_SIZE
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#define SIGFRAME_REG_SIZE 4
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#endif
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for (; fi; fi = fi->next)
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if (in_sigtramp(fi->pc, 0)) {
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int offset;
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if (regno == PC_REGNUM) offset = SIGFRAME_PC_OFF;
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else if (regno < 32) offset = (SIGFRAME_REGSAVE_OFF
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+ regno * SIGFRAME_REG_SIZE);
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else return 0;
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return read_memory_integer(fi->frame + offset, 4);
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}
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else if (regno == SP_REGNUM) return fi->frame;
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else if (fi->saved_regs->regs[regno])
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return read_memory_integer(fi->saved_regs->regs[regno], 4);
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return read_register(regno);
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}
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int
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mips_frame_saved_pc(frame)
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FRAME frame;
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{
|
||
mips_extra_func_info_t proc_desc = frame->proc_desc;
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int pcreg = proc_desc ? PROC_PC_REG(proc_desc) : RA_REGNUM;
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if (proc_desc && PROC_DESC_IS_DUMMY(proc_desc))
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return read_memory_integer(frame->frame - 4, 4);
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return read_next_frame_reg(frame, pcreg);
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}
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static struct mips_extra_func_info temp_proc_desc;
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static struct frame_saved_regs temp_saved_regs;
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/* This fencepost looks highly suspicious to me. Removing it also
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seems suspicious as it could affect remote debugging across serial
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lines. */
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static CORE_ADDR
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heuristic_proc_start(pc)
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CORE_ADDR pc;
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{
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CORE_ADDR start_pc = pc;
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CORE_ADDR fence = start_pc - heuristic_fence_post;
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if (start_pc == 0) return 0;
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if (heuristic_fence_post == UINT_MAX
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|| fence < VM_MIN_ADDRESS)
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fence = VM_MIN_ADDRESS;
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/* search back for previous return */
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for (start_pc -= 4; ; start_pc -= 4)
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if (start_pc < fence)
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{
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/* It's not clear to me why we reach this point when
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stop_soon_quietly, but with this test, at least we
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don't print out warnings for every child forked (eg, on
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decstation). 22apr93 rich@cygnus.com. */
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if (!stop_soon_quietly)
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{
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static int blurb_printed = 0;
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if (fence == VM_MIN_ADDRESS)
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warning("Hit beginning of text section without finding");
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else
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warning("Hit heuristic-fence-post without finding");
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warning("enclosing function for address 0x%x", pc);
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if (!blurb_printed)
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{
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printf_filtered ("\
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This warning occurs if you are debugging a function without any symbols\n\
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(for example, in a stripped executable). In that case, you may wish to\n\
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increase the size of the search with the `set heuristic-fence-post' command.\n\
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\n\
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Otherwise, you told GDB there was a function where there isn't one, or\n\
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(more likely) you have encountered a bug in GDB.\n");
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blurb_printed = 1;
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}
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}
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return 0;
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}
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else if (ABOUT_TO_RETURN(start_pc))
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break;
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start_pc += 8; /* skip return, and its delay slot */
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#if 0
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/* skip nops (usually 1) 0 - is this */
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while (start_pc < pc && read_memory_integer (start_pc, 4) == 0)
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start_pc += 4;
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#endif
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return start_pc;
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}
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static mips_extra_func_info_t
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heuristic_proc_desc(start_pc, limit_pc, next_frame)
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CORE_ADDR start_pc, limit_pc;
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FRAME next_frame;
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{
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CORE_ADDR sp = next_frame ? next_frame->frame : read_register (SP_REGNUM);
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CORE_ADDR cur_pc;
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int frame_size;
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int has_frame_reg = 0;
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int reg30 = 0; /* Value of $r30. Used by gcc for frame-pointer */
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unsigned long reg_mask = 0;
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if (start_pc == 0) return NULL;
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memset(&temp_proc_desc, '\0', sizeof(temp_proc_desc));
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memset(&temp_saved_regs, '\0', sizeof(struct frame_saved_regs));
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PROC_LOW_ADDR(&temp_proc_desc) = start_pc;
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if (start_pc + 200 < limit_pc) limit_pc = start_pc + 200;
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restart:
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frame_size = 0;
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for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4) {
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char buf[4];
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unsigned long word;
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int status;
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status = read_memory_nobpt (cur_pc, buf, 4);
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if (status) memory_error (status, cur_pc);
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word = extract_unsigned_integer (buf, 4);
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if ((word & 0xFFFF0000) == 0x27bd0000) /* addiu $sp,$sp,-i */
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frame_size += (-word) & 0xFFFF;
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else if ((word & 0xFFFF0000) == 0x23bd0000) /* addu $sp,$sp,-i */
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frame_size += (-word) & 0xFFFF;
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else if ((word & 0xFFE00000) == 0xafa00000) { /* sw reg,offset($sp) */
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int reg = (word & 0x001F0000) >> 16;
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reg_mask |= 1 << reg;
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temp_saved_regs.regs[reg] = sp + (word & 0xffff);
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}
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else if ((word & 0xFFFF0000) == 0x27be0000) { /* addiu $30,$sp,size */
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if ((word & 0xffff) != frame_size)
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reg30 = sp + (word & 0xffff);
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else if (!has_frame_reg) {
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int alloca_adjust;
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has_frame_reg = 1;
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reg30 = read_next_frame_reg(next_frame, 30);
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alloca_adjust = reg30 - (sp + (word & 0xffff));
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if (alloca_adjust > 0) {
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/* FP > SP + frame_size. This may be because
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* of an alloca or somethings similar.
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* Fix sp to "pre-alloca" value, and try again.
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*/
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sp += alloca_adjust;
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goto restart;
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}
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}
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}
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else if ((word & 0xFFE00000) == 0xafc00000) { /* sw reg,offset($30) */
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int reg = (word & 0x001F0000) >> 16;
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reg_mask |= 1 << reg;
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temp_saved_regs.regs[reg] = reg30 + (word & 0xffff);
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}
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}
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if (has_frame_reg) {
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PROC_FRAME_REG(&temp_proc_desc) = 30;
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PROC_FRAME_OFFSET(&temp_proc_desc) = 0;
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}
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else {
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PROC_FRAME_REG(&temp_proc_desc) = SP_REGNUM;
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PROC_FRAME_OFFSET(&temp_proc_desc) = frame_size;
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}
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PROC_REG_MASK(&temp_proc_desc) = reg_mask;
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PROC_PC_REG(&temp_proc_desc) = RA_REGNUM;
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return &temp_proc_desc;
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}
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static mips_extra_func_info_t
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find_proc_desc(pc, next_frame)
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CORE_ADDR pc;
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FRAME next_frame;
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{
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mips_extra_func_info_t proc_desc;
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struct block *b = block_for_pc(pc);
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struct symbol *sym;
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CORE_ADDR startaddr;
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find_pc_partial_function (pc, NULL, &startaddr, NULL);
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if (b == NULL)
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sym = NULL;
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else
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{
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if (startaddr > BLOCK_START (b))
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/* This is the "pathological" case referred to in a comment in
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print_frame_info. It might be better to move this check into
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symbol reading. */
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sym = NULL;
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else
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sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE,
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0, NULL);
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}
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if (sym)
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{
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/* IF this is the topmost frame AND
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* (this proc does not have debugging information OR
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* the PC is in the procedure prologue)
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* THEN create a "heuristic" proc_desc (by analyzing
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* the actual code) to replace the "official" proc_desc.
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*/
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proc_desc = (mips_extra_func_info_t)SYMBOL_VALUE(sym);
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if (next_frame == NULL) {
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struct symtab_and_line val;
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struct symbol *proc_symbol =
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PROC_DESC_IS_DUMMY(proc_desc) ? 0 : PROC_SYMBOL(proc_desc);
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if (proc_symbol) {
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val = find_pc_line (BLOCK_START
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(SYMBOL_BLOCK_VALUE(proc_symbol)),
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0);
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val.pc = val.end ? val.end : pc;
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}
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if (!proc_symbol || pc < val.pc) {
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mips_extra_func_info_t found_heuristic =
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heuristic_proc_desc(PROC_LOW_ADDR(proc_desc),
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pc, next_frame);
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if (found_heuristic) proc_desc = found_heuristic;
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}
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}
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}
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else
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{
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/* Is linked_proc_desc_table really necessary? It only seems to be used
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by procedure call dummys. However, the procedures being called ought
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to have their own proc_descs, and even if they don't,
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heuristic_proc_desc knows how to create them! */
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|
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register struct linked_proc_info *link;
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for (link = linked_proc_desc_table; link; link = link->next)
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if (PROC_LOW_ADDR(&link->info) <= pc
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&& PROC_HIGH_ADDR(&link->info) > pc)
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return &link->info;
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|
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if (startaddr == 0)
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startaddr = heuristic_proc_start (pc);
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||
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||
proc_desc =
|
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heuristic_proc_desc (startaddr, pc, next_frame);
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||
}
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||
return proc_desc;
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||
}
|
||
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mips_extra_func_info_t cached_proc_desc;
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||
|
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FRAME_ADDR
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mips_frame_chain(frame)
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FRAME frame;
|
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{
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mips_extra_func_info_t proc_desc;
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CORE_ADDR saved_pc = FRAME_SAVED_PC(frame);
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if (saved_pc == 0 || inside_entry_file (saved_pc))
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return 0;
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proc_desc = find_proc_desc(saved_pc, frame);
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if (!proc_desc)
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return 0;
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||
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cached_proc_desc = proc_desc;
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||
|
||
/* If no frame pointer and frame size is zero, we must be at end
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of stack (or otherwise hosed). If we don't check frame size,
|
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we loop forever if we see a zero size frame. */
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if (PROC_FRAME_REG (proc_desc) == SP_REGNUM
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&& PROC_FRAME_OFFSET (proc_desc) == 0
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/* The previous frame from a sigtramp frame might be frameless
|
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and have frame size zero. */
|
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&& !frame->signal_handler_caller)
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return 0;
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else
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return read_next_frame_reg(frame, PROC_FRAME_REG(proc_desc))
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+ PROC_FRAME_OFFSET(proc_desc);
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||
}
|
||
|
||
void
|
||
init_extra_frame_info(fci)
|
||
struct frame_info *fci;
|
||
{
|
||
extern struct obstack frame_cache_obstack;
|
||
/* Use proc_desc calculated in frame_chain */
|
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mips_extra_func_info_t proc_desc =
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fci->next ? cached_proc_desc : find_proc_desc(fci->pc, fci->next);
|
||
|
||
fci->saved_regs = (struct frame_saved_regs*)
|
||
obstack_alloc (&frame_cache_obstack, sizeof(struct frame_saved_regs));
|
||
memset (fci->saved_regs, 0, sizeof (struct frame_saved_regs));
|
||
fci->proc_desc =
|
||
proc_desc == &temp_proc_desc ? 0 : proc_desc;
|
||
if (proc_desc)
|
||
{
|
||
int ireg;
|
||
CORE_ADDR reg_position;
|
||
/* r0 bit means kernel trap */
|
||
int kernel_trap = PROC_REG_MASK(proc_desc) & 1;
|
||
|
||
/* Fixup frame-pointer - only needed for top frame */
|
||
/* This may not be quite right, if proc has a real frame register.
|
||
Get the value of the frame relative sp, procedure might have been
|
||
interrupted by a signal at it's very start. */
|
||
if (fci->pc == PROC_LOW_ADDR(proc_desc) && !PROC_DESC_IS_DUMMY(proc_desc))
|
||
fci->frame = READ_FRAME_REG(fci, SP_REGNUM);
|
||
else
|
||
fci->frame = READ_FRAME_REG(fci, PROC_FRAME_REG(proc_desc))
|
||
+ PROC_FRAME_OFFSET(proc_desc);
|
||
|
||
if (proc_desc == &temp_proc_desc)
|
||
*fci->saved_regs = temp_saved_regs;
|
||
else
|
||
{
|
||
/* What registers have been saved? Bitmasks. */
|
||
unsigned long gen_mask, float_mask;
|
||
|
||
gen_mask = kernel_trap ? 0xFFFFFFFF : PROC_REG_MASK(proc_desc);
|
||
float_mask = kernel_trap ? 0xFFFFFFFF : PROC_FREG_MASK(proc_desc);
|
||
|
||
if (/* In any frame other than the innermost, we assume that all
|
||
registers have been saved. This assumes that all register
|
||
saves in a function happen before the first function
|
||
call. */
|
||
fci->next == NULL
|
||
|
||
/* In a dummy frame we know exactly where things are saved. */
|
||
&& !PROC_DESC_IS_DUMMY (proc_desc)
|
||
|
||
/* Not sure exactly what kernel_trap means, but if it means
|
||
the kernel saves the registers without a prologue doing it,
|
||
we better not examine the prologue to see whether registers
|
||
have been saved yet. */
|
||
&& !kernel_trap)
|
||
{
|
||
/* We need to figure out whether the registers that the proc_desc
|
||
claims are saved have been saved yet. */
|
||
|
||
CORE_ADDR addr;
|
||
int status;
|
||
char buf[4];
|
||
unsigned long inst;
|
||
|
||
/* Bitmasks; set if we have found a save for the register. */
|
||
unsigned long gen_save_found = 0;
|
||
unsigned long float_save_found = 0;
|
||
|
||
for (addr = PROC_LOW_ADDR (proc_desc);
|
||
addr < fci->pc && (gen_mask != gen_save_found
|
||
|| float_mask != float_save_found);
|
||
addr += 4)
|
||
{
|
||
status = read_memory_nobpt (addr, buf, 4);
|
||
if (status)
|
||
memory_error (status, addr);
|
||
inst = extract_unsigned_integer (buf, 4);
|
||
if (/* sw reg,n($sp) */
|
||
(inst & 0xffe00000) == 0xafa00000
|
||
|
||
/* sw reg,n($r30) */
|
||
|| (inst & 0xffe00000) == 0xafc00000)
|
||
{
|
||
/* It might be possible to use the instruction to
|
||
find the offset, rather than the code below which
|
||
is based on things being in a certain order in the
|
||
frame, but figuring out what the instruction's offset
|
||
is relative to might be a little tricky. */
|
||
int reg = (inst & 0x001f0000) >> 16;
|
||
gen_save_found |= (1 << reg);
|
||
}
|
||
else if (/* swc1 freg,n($sp) */
|
||
(inst & 0xffe00000) == 0xe7a00000
|
||
|
||
/* swc1 freg,n($r30) */
|
||
|| (inst & 0xffe00000) == 0xe7c00000)
|
||
{
|
||
int reg = ((inst & 0x001f0000) >> 16);
|
||
float_save_found |= (1 << reg);
|
||
}
|
||
}
|
||
gen_mask = gen_save_found;
|
||
float_mask = float_save_found;
|
||
}
|
||
|
||
/* Fill in the offsets for the registers which gen_mask says
|
||
were saved. */
|
||
reg_position = fci->frame + PROC_REG_OFFSET (proc_desc);
|
||
for (ireg= 31; gen_mask; --ireg, gen_mask <<= 1)
|
||
if (gen_mask & 0x80000000)
|
||
{
|
||
fci->saved_regs->regs[ireg] = reg_position;
|
||
reg_position -= 4;
|
||
}
|
||
/* Fill in the offsets for the registers which float_mask says
|
||
were saved. */
|
||
reg_position = fci->frame + PROC_FREG_OFFSET (proc_desc);
|
||
|
||
/* The freg_offset points to where the first *double* register
|
||
is saved. So skip to the high-order word. */
|
||
reg_position += 4;
|
||
for (ireg = 31; float_mask; --ireg, float_mask <<= 1)
|
||
if (float_mask & 0x80000000)
|
||
{
|
||
fci->saved_regs->regs[FP0_REGNUM+ireg] = reg_position;
|
||
reg_position -= 4;
|
||
}
|
||
}
|
||
|
||
/* hack: if argument regs are saved, guess these contain args */
|
||
if ((PROC_REG_MASK(proc_desc) & 0xF0) == 0) fci->num_args = -1;
|
||
else if ((PROC_REG_MASK(proc_desc) & 0x80) == 0) fci->num_args = 4;
|
||
else if ((PROC_REG_MASK(proc_desc) & 0x40) == 0) fci->num_args = 3;
|
||
else if ((PROC_REG_MASK(proc_desc) & 0x20) == 0) fci->num_args = 2;
|
||
else if ((PROC_REG_MASK(proc_desc) & 0x10) == 0) fci->num_args = 1;
|
||
|
||
fci->saved_regs->regs[PC_REGNUM] = fci->saved_regs->regs[RA_REGNUM];
|
||
}
|
||
}
|
||
|
||
/* MIPS stack frames are almost impenetrable. When execution stops,
|
||
we basically have to look at symbol information for the function
|
||
that we stopped in, which tells us *which* register (if any) is
|
||
the base of the frame pointer, and what offset from that register
|
||
the frame itself is at.
|
||
|
||
This presents a problem when trying to examine a stack in memory
|
||
(that isn't executing at the moment), using the "frame" command. We
|
||
don't have a PC, nor do we have any registers except SP.
|
||
|
||
This routine takes two arguments, SP and PC, and tries to make the
|
||
cached frames look as if these two arguments defined a frame on the
|
||
cache. This allows the rest of info frame to extract the important
|
||
arguments without difficulty. */
|
||
|
||
FRAME
|
||
setup_arbitrary_frame (argc, argv)
|
||
int argc;
|
||
FRAME_ADDR *argv;
|
||
{
|
||
if (argc != 2)
|
||
error ("MIPS frame specifications require two arguments: sp and pc");
|
||
|
||
return create_new_frame (argv[0], argv[1]);
|
||
}
|
||
|
||
|
||
CORE_ADDR
|
||
mips_push_arguments(nargs, args, sp, struct_return, struct_addr)
|
||
int nargs;
|
||
value *args;
|
||
CORE_ADDR sp;
|
||
int struct_return;
|
||
CORE_ADDR struct_addr;
|
||
{
|
||
register i;
|
||
int accumulate_size = struct_return ? 4 : 0;
|
||
struct mips_arg { char *contents; int len; int offset; };
|
||
struct mips_arg *mips_args =
|
||
(struct mips_arg*)alloca(nargs * sizeof(struct mips_arg));
|
||
register struct mips_arg *m_arg;
|
||
for (i = 0, m_arg = mips_args; i < nargs; i++, m_arg++) {
|
||
extern value value_arg_coerce();
|
||
value arg = value_arg_coerce (args[i]);
|
||
m_arg->len = TYPE_LENGTH (VALUE_TYPE (arg));
|
||
/* This entire mips-specific routine is because doubles must be aligned
|
||
* on 8-byte boundaries. It still isn't quite right, because MIPS decided
|
||
* to align 'struct {int a, b}' on 4-byte boundaries (even though this
|
||
* breaks their varargs implementation...). A correct solution
|
||
* requires an simulation of gcc's 'alignof' (and use of 'alignof'
|
||
* in stdarg.h/varargs.h).
|
||
*/
|
||
if (m_arg->len > 4) accumulate_size = (accumulate_size + 7) & -8;
|
||
m_arg->offset = accumulate_size;
|
||
accumulate_size = (accumulate_size + m_arg->len + 3) & -4;
|
||
m_arg->contents = VALUE_CONTENTS(arg);
|
||
}
|
||
accumulate_size = (accumulate_size + 7) & (-8);
|
||
if (accumulate_size < 16) accumulate_size = 16;
|
||
sp -= accumulate_size;
|
||
for (i = nargs; m_arg--, --i >= 0; )
|
||
write_memory(sp + m_arg->offset, m_arg->contents, m_arg->len);
|
||
if (struct_return)
|
||
{
|
||
char buf[TARGET_PTR_BIT / HOST_CHAR_BIT];
|
||
|
||
store_address (buf, sizeof buf, struct_addr);
|
||
write_memory (sp, buf, sizeof buf);
|
||
}
|
||
return sp;
|
||
}
|
||
|
||
/* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */
|
||
#define MASK(i,j) (((1 << ((j)+1))-1) ^ ((1 << (i))-1))
|
||
|
||
void
|
||
mips_push_dummy_frame()
|
||
{
|
||
char buffer[MAX_REGISTER_RAW_SIZE];
|
||
int ireg;
|
||
struct linked_proc_info *link = (struct linked_proc_info*)
|
||
xmalloc(sizeof(struct linked_proc_info));
|
||
mips_extra_func_info_t proc_desc = &link->info;
|
||
CORE_ADDR sp = read_register (SP_REGNUM);
|
||
CORE_ADDR save_address;
|
||
link->next = linked_proc_desc_table;
|
||
linked_proc_desc_table = link;
|
||
#define PUSH_FP_REGNUM 16 /* must be a register preserved across calls */
|
||
#define GEN_REG_SAVE_MASK MASK(1,16)|MASK(24,28)|(1<<31)
|
||
#define GEN_REG_SAVE_COUNT 22
|
||
#define FLOAT_REG_SAVE_MASK MASK(0,19)
|
||
#define FLOAT_REG_SAVE_COUNT 20
|
||
#define SPECIAL_REG_SAVE_COUNT 4
|
||
/*
|
||
* The registers we must save are all those not preserved across
|
||
* procedure calls. Dest_Reg (see tm-mips.h) must also be saved.
|
||
* In addition, we must save the PC, and PUSH_FP_REGNUM.
|
||
* (Ideally, we should also save MDLO/-HI and FP Control/Status reg.)
|
||
*
|
||
* Dummy frame layout:
|
||
* (high memory)
|
||
* Saved PC
|
||
* Saved MMHI, MMLO, FPC_CSR
|
||
* Saved R31
|
||
* Saved R28
|
||
* ...
|
||
* Saved R1
|
||
* Saved D18 (i.e. F19, F18)
|
||
* ...
|
||
* Saved D0 (i.e. F1, F0)
|
||
* CALL_DUMMY (subroutine stub; see tm-mips.h)
|
||
* Parameter build area (not yet implemented)
|
||
* (low memory)
|
||
*/
|
||
PROC_REG_MASK(proc_desc) = GEN_REG_SAVE_MASK;
|
||
PROC_FREG_MASK(proc_desc) = mips_fpu ? FLOAT_REG_SAVE_MASK : 0;
|
||
PROC_REG_OFFSET(proc_desc) = /* offset of (Saved R31) from FP */
|
||
-sizeof(long) - 4 * SPECIAL_REG_SAVE_COUNT;
|
||
PROC_FREG_OFFSET(proc_desc) = /* offset of (Saved D18) from FP */
|
||
-sizeof(double) - 4 * (SPECIAL_REG_SAVE_COUNT + GEN_REG_SAVE_COUNT);
|
||
/* save general registers */
|
||
save_address = sp + PROC_REG_OFFSET(proc_desc);
|
||
for (ireg = 32; --ireg >= 0; )
|
||
if (PROC_REG_MASK(proc_desc) & (1 << ireg))
|
||
{
|
||
store_unsigned_integer (buffer, REGISTER_RAW_SIZE (ireg),
|
||
read_register (ireg));
|
||
write_memory (save_address, buffer, REGISTER_RAW_SIZE (ireg));
|
||
save_address -= 4;
|
||
}
|
||
/* save floating-points registers starting with high order word */
|
||
save_address = sp + PROC_FREG_OFFSET(proc_desc) + 4;
|
||
for (ireg = 32; --ireg >= 0; )
|
||
if (PROC_FREG_MASK(proc_desc) & (1 << ireg))
|
||
{
|
||
store_unsigned_integer (buffer, 4, read_register (ireg + FP0_REGNUM));
|
||
write_memory (save_address, buffer, 4);
|
||
save_address -= 4;
|
||
}
|
||
write_register (PUSH_FP_REGNUM, sp);
|
||
PROC_FRAME_REG(proc_desc) = PUSH_FP_REGNUM;
|
||
PROC_FRAME_OFFSET(proc_desc) = 0;
|
||
store_unsigned_integer (buffer, REGISTER_RAW_SIZE (PC_REGNUM),
|
||
read_register (PC_REGNUM));
|
||
write_memory (sp - 4, buffer, REGISTER_RAW_SIZE (PC_REGNUM));
|
||
store_unsigned_integer (buffer, REGISTER_RAW_SIZE (HI_REGNUM),
|
||
read_register (HI_REGNUM));
|
||
write_memory (sp - 8, buffer, REGISTER_RAW_SIZE (HI_REGNUM));
|
||
store_unsigned_integer (buffer, REGISTER_RAW_SIZE (LO_REGNUM),
|
||
read_register (LO_REGNUM));
|
||
write_memory (sp - 12, buffer, REGISTER_RAW_SIZE (LO_REGNUM));
|
||
store_unsigned_integer
|
||
(buffer,
|
||
REGISTER_RAW_SIZE (FCRCS_REGNUM),
|
||
mips_fpu ? read_register (FCRCS_REGNUM) : 0);
|
||
write_memory (sp - 16, buffer, REGISTER_RAW_SIZE (FCRCS_REGNUM));
|
||
sp -= 4 * (GEN_REG_SAVE_COUNT
|
||
+ (mips_fpu ? FLOAT_REG_SAVE_COUNT : 0)
|
||
+ SPECIAL_REG_SAVE_COUNT);
|
||
write_register (SP_REGNUM, sp);
|
||
PROC_LOW_ADDR(proc_desc) = sp - CALL_DUMMY_SIZE + CALL_DUMMY_START_OFFSET;
|
||
PROC_HIGH_ADDR(proc_desc) = sp;
|
||
SET_PROC_DESC_IS_DUMMY(proc_desc);
|
||
PROC_PC_REG(proc_desc) = RA_REGNUM;
|
||
}
|
||
|
||
void
|
||
mips_pop_frame()
|
||
{
|
||
register int regnum;
|
||
FRAME frame = get_current_frame ();
|
||
CORE_ADDR new_sp = frame->frame;
|
||
|
||
mips_extra_func_info_t proc_desc = frame->proc_desc;
|
||
|
||
write_register (PC_REGNUM, FRAME_SAVED_PC(frame));
|
||
if (proc_desc)
|
||
{
|
||
for (regnum = 32; --regnum >= 0; )
|
||
if (PROC_REG_MASK(proc_desc) & (1 << regnum))
|
||
write_register (regnum,
|
||
read_memory_integer (frame->saved_regs->regs[regnum],
|
||
4));
|
||
for (regnum = 32; --regnum >= 0; )
|
||
if (PROC_FREG_MASK(proc_desc) & (1 << regnum))
|
||
write_register (regnum + FP0_REGNUM,
|
||
read_memory_integer (frame->saved_regs->regs[regnum + FP0_REGNUM], 4));
|
||
}
|
||
write_register (SP_REGNUM, new_sp);
|
||
flush_cached_frames ();
|
||
/* We let mips_init_extra_frame_info figure out the frame pointer */
|
||
set_current_frame (create_new_frame (0, read_pc ()));
|
||
|
||
if (proc_desc && PROC_DESC_IS_DUMMY(proc_desc))
|
||
{
|
||
struct linked_proc_info *pi_ptr, *prev_ptr;
|
||
|
||
for (pi_ptr = linked_proc_desc_table, prev_ptr = NULL;
|
||
pi_ptr != NULL;
|
||
prev_ptr = pi_ptr, pi_ptr = pi_ptr->next)
|
||
{
|
||
if (&pi_ptr->info == proc_desc)
|
||
break;
|
||
}
|
||
|
||
if (pi_ptr == NULL)
|
||
error ("Can't locate dummy extra frame info\n");
|
||
|
||
if (prev_ptr != NULL)
|
||
prev_ptr->next = pi_ptr->next;
|
||
else
|
||
linked_proc_desc_table = pi_ptr->next;
|
||
|
||
free (pi_ptr);
|
||
|
||
write_register (HI_REGNUM, read_memory_integer(new_sp - 8, 4));
|
||
write_register (LO_REGNUM, read_memory_integer(new_sp - 12, 4));
|
||
if (mips_fpu)
|
||
write_register (FCRCS_REGNUM, read_memory_integer(new_sp - 16, 4));
|
||
}
|
||
}
|
||
|
||
static void
|
||
mips_print_register (regnum, all)
|
||
int regnum, all;
|
||
{
|
||
unsigned char raw_buffer[MAX_REGISTER_RAW_SIZE];
|
||
|
||
/* Get the data in raw format. */
|
||
if (read_relative_register_raw_bytes (regnum, raw_buffer))
|
||
{
|
||
printf_filtered ("%s: [Invalid]", reg_names[regnum]);
|
||
return;
|
||
}
|
||
|
||
/* If an even floating pointer register, also print as double. */
|
||
if (regnum >= FP0_REGNUM && regnum < FP0_REGNUM+32
|
||
&& !((regnum-FP0_REGNUM) & 1)) {
|
||
char dbuffer[MAX_REGISTER_RAW_SIZE];
|
||
|
||
read_relative_register_raw_bytes (regnum, dbuffer);
|
||
read_relative_register_raw_bytes (regnum+1, dbuffer+4);
|
||
#ifdef REGISTER_CONVERT_TO_TYPE
|
||
REGISTER_CONVERT_TO_TYPE(regnum, builtin_type_double, dbuffer);
|
||
#endif
|
||
printf_filtered ("(d%d: ", regnum-FP0_REGNUM);
|
||
val_print (builtin_type_double, dbuffer, 0,
|
||
gdb_stdout, 0, 1, 0, Val_pretty_default);
|
||
printf_filtered ("); ");
|
||
}
|
||
fputs_filtered (reg_names[regnum], gdb_stdout);
|
||
|
||
/* The problem with printing numeric register names (r26, etc.) is that
|
||
the user can't use them on input. Probably the best solution is to
|
||
fix it so that either the numeric or the funky (a2, etc.) names
|
||
are accepted on input. */
|
||
if (regnum < 32)
|
||
printf_filtered ("(r%d): ", regnum);
|
||
else
|
||
printf_filtered (": ");
|
||
|
||
/* If virtual format is floating, print it that way. */
|
||
if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (regnum)) == TYPE_CODE_FLT
|
||
&& ! INVALID_FLOAT (raw_buffer, REGISTER_VIRTUAL_SIZE(regnum))) {
|
||
val_print (REGISTER_VIRTUAL_TYPE (regnum), raw_buffer, 0,
|
||
gdb_stdout, 0, 1, 0, Val_pretty_default);
|
||
}
|
||
/* Else print as integer in hex. */
|
||
else
|
||
{
|
||
long val;
|
||
|
||
val = extract_signed_integer (raw_buffer,
|
||
REGISTER_RAW_SIZE (regnum));
|
||
|
||
if (val == 0)
|
||
printf_filtered ("0");
|
||
else if (all)
|
||
/* FIXME: We should be printing this in a fixed field width, so that
|
||
registers line up. */
|
||
printf_filtered (local_hex_format(), val);
|
||
else
|
||
printf_filtered ("%s=%ld", local_hex_string(val), val);
|
||
}
|
||
}
|
||
|
||
/* Replacement for generic do_registers_info. */
|
||
void
|
||
mips_do_registers_info (regnum, fpregs)
|
||
int regnum;
|
||
int fpregs;
|
||
{
|
||
if (regnum != -1) {
|
||
mips_print_register (regnum, 0);
|
||
printf_filtered ("\n");
|
||
}
|
||
else {
|
||
for (regnum = 0; regnum < NUM_REGS; ) {
|
||
if ((!fpregs) && regnum >= FP0_REGNUM && regnum <= FCRIR_REGNUM) {
|
||
regnum++;
|
||
continue;
|
||
}
|
||
mips_print_register (regnum, 1);
|
||
regnum++;
|
||
if ((regnum & 3) == 0 || regnum == NUM_REGS)
|
||
printf_filtered (";\n");
|
||
else
|
||
printf_filtered ("; ");
|
||
}
|
||
}
|
||
}
|
||
/* Return number of args passed to a frame. described by FIP.
|
||
Can return -1, meaning no way to tell. */
|
||
|
||
int
|
||
mips_frame_num_args(fip)
|
||
FRAME fip;
|
||
{
|
||
#if 0
|
||
struct chain_info_t *p;
|
||
|
||
p = mips_find_cached_frame(FRAME_FP(fip));
|
||
if (p->valid)
|
||
return p->the_info.numargs;
|
||
#endif
|
||
return -1;
|
||
}
|
||
|
||
#if 0
|
||
/* Is this a branch with a delay slot? */
|
||
static int
|
||
is_delayed (insn)
|
||
unsigned long insn;
|
||
{
|
||
int i;
|
||
for (i = 0; i < NUMOPCODES; ++i)
|
||
if (mips_opcodes[i].pinfo != INSN_MACRO
|
||
&& (insn & mips_opcodes[i].mask) == mips_opcodes[i].match)
|
||
break;
|
||
return (i < NUMOPCODES
|
||
&& (mips_opcodes[i].pinfo & (INSN_UNCOND_BRANCH_DELAY
|
||
| INSN_COND_BRANCH_DELAY
|
||
| INSN_COND_BRANCH_LIKELY)));
|
||
}
|
||
#endif
|
||
|
||
/* To skip prologues, I use this predicate. Returns either PC itself
|
||
if the code at PC does not look like a function prologue; otherwise
|
||
returns an address that (if we're lucky) follows the prologue. If
|
||
LENIENT, then we must skip everything which is involved in setting
|
||
up the frame (it's OK to skip more, just so long as we don't skip
|
||
anything which might clobber the registers which are being saved.
|
||
We must skip more in the case where part of the prologue is in the
|
||
delay slot of a non-prologue instruction). */
|
||
|
||
CORE_ADDR
|
||
mips_skip_prologue (pc, lenient)
|
||
CORE_ADDR pc;
|
||
int lenient;
|
||
{
|
||
unsigned long inst;
|
||
int offset;
|
||
int seen_sp_adjust = 0;
|
||
|
||
/* Skip the typical prologue instructions. These are the stack adjustment
|
||
instruction and the instructions that save registers on the stack
|
||
or in the gcc frame. */
|
||
for (offset = 0; offset < 100; offset += 4)
|
||
{
|
||
char buf[4];
|
||
int status;
|
||
|
||
status = read_memory_nobpt (pc + offset, buf, 4);
|
||
if (status)
|
||
memory_error (status, pc + offset);
|
||
inst = extract_unsigned_integer (buf, 4);
|
||
|
||
#if 0
|
||
if (lenient && is_delayed (inst))
|
||
continue;
|
||
#endif
|
||
|
||
if ((inst & 0xffff0000) == 0x27bd0000) /* addiu $sp,$sp,offset */
|
||
seen_sp_adjust = 1;
|
||
else if ((inst & 0xFFE00000) == 0xAFA00000 && (inst & 0x001F0000))
|
||
continue; /* sw reg,n($sp) */
|
||
/* reg != $zero */
|
||
else if ((inst & 0xFFE00000) == 0xE7A00000) /* swc1 freg,n($sp) */
|
||
continue;
|
||
else if ((inst & 0xF3E00000) == 0xA3C00000 && (inst & 0x001F0000))
|
||
/* sx reg,n($s8) */
|
||
continue; /* reg != $zero */
|
||
else if (inst == 0x03A0F021) /* move $s8,$sp */
|
||
continue;
|
||
else if ((inst & 0xFF9F07FF) == 0x00800021) /* move reg,$a0-$a3 */
|
||
continue;
|
||
else if ((inst & 0xffff0000) == 0x3c1c0000) /* lui $gp,n */
|
||
continue;
|
||
else if ((inst & 0xffff0000) == 0x279c0000) /* addiu $gp,$gp,n */
|
||
continue;
|
||
else if (inst == 0x0399e021 /* addu $gp,$gp,$t9 */
|
||
|| inst == 0x033ce021) /* addu $gp,$t9,$gp */
|
||
continue;
|
||
else
|
||
break;
|
||
}
|
||
return pc + offset;
|
||
|
||
/* FIXME schauer. The following code seems no longer necessary if we
|
||
always skip the typical prologue instructions. */
|
||
|
||
#if 0
|
||
if (seen_sp_adjust)
|
||
return pc + offset;
|
||
|
||
/* Well, it looks like a frameless. Let's make sure.
|
||
Note that we are not called on the current PC,
|
||
but on the function`s start PC, and I have definitely
|
||
seen optimized code that adjusts the SP quite later */
|
||
b = block_for_pc(pc);
|
||
if (!b) return pc;
|
||
|
||
f = lookup_symbol(MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE, 0, NULL);
|
||
if (!f) return pc;
|
||
/* Ideally, I would like to use the adjusted info
|
||
from mips_frame_info(), but for all practical
|
||
purposes it will not matter (and it would require
|
||
a different definition of SKIP_PROLOGUE())
|
||
|
||
Actually, it would not hurt to skip the storing
|
||
of arguments on the stack as well. */
|
||
if (((mips_extra_func_info_t)SYMBOL_VALUE(f))->pdr.frameoffset)
|
||
return pc + 4;
|
||
|
||
return pc;
|
||
#endif
|
||
}
|
||
|
||
#if 0
|
||
/* The lenient prologue stuff should be superceded by the code in
|
||
init_extra_frame_info which looks to see whether the stores mentioned
|
||
in the proc_desc have actually taken place. */
|
||
|
||
/* Is address PC in the prologue (loosely defined) for function at
|
||
STARTADDR? */
|
||
|
||
static int
|
||
mips_in_lenient_prologue (startaddr, pc)
|
||
CORE_ADDR startaddr;
|
||
CORE_ADDR pc;
|
||
{
|
||
CORE_ADDR end_prologue = mips_skip_prologue (startaddr, 1);
|
||
return pc >= startaddr && pc < end_prologue;
|
||
}
|
||
#endif
|
||
|
||
/* Given a return value in `regbuf' with a type `valtype',
|
||
extract and copy its value into `valbuf'. */
|
||
void
|
||
mips_extract_return_value (valtype, regbuf, valbuf)
|
||
struct type *valtype;
|
||
char regbuf[REGISTER_BYTES];
|
||
char *valbuf;
|
||
{
|
||
int regnum;
|
||
|
||
regnum = TYPE_CODE (valtype) == TYPE_CODE_FLT && mips_fpu ? FP0_REGNUM : 2;
|
||
|
||
memcpy (valbuf, regbuf + REGISTER_BYTE (regnum), TYPE_LENGTH (valtype));
|
||
#ifdef REGISTER_CONVERT_TO_TYPE
|
||
REGISTER_CONVERT_TO_TYPE(regnum, valtype, valbuf);
|
||
#endif
|
||
}
|
||
|
||
/* Given a return value in `regbuf' with a type `valtype',
|
||
write it's value into the appropriate register. */
|
||
void
|
||
mips_store_return_value (valtype, valbuf)
|
||
struct type *valtype;
|
||
char *valbuf;
|
||
{
|
||
int regnum;
|
||
char raw_buffer[MAX_REGISTER_RAW_SIZE];
|
||
|
||
regnum = TYPE_CODE (valtype) == TYPE_CODE_FLT && mips_fpu ? FP0_REGNUM : 2;
|
||
memcpy(raw_buffer, valbuf, TYPE_LENGTH (valtype));
|
||
|
||
#ifdef REGISTER_CONVERT_FROM_TYPE
|
||
REGISTER_CONVERT_FROM_TYPE(regnum, valtype, raw_buffer);
|
||
#endif
|
||
|
||
write_register_bytes(REGISTER_BYTE (regnum), raw_buffer, TYPE_LENGTH (valtype));
|
||
}
|
||
|
||
/* These exist in mdebugread.c. */
|
||
extern CORE_ADDR sigtramp_address, sigtramp_end;
|
||
extern void fixup_sigtramp PARAMS ((void));
|
||
|
||
/* Exported procedure: Is PC in the signal trampoline code */
|
||
|
||
int
|
||
in_sigtramp (pc, ignore)
|
||
CORE_ADDR pc;
|
||
char *ignore; /* function name */
|
||
{
|
||
if (sigtramp_address == 0)
|
||
fixup_sigtramp ();
|
||
return (pc >= sigtramp_address && pc < sigtramp_end);
|
||
}
|
||
|
||
static void reinit_frame_cache_sfunc PARAMS ((char *, int,
|
||
struct cmd_list_element *));
|
||
|
||
/* Just like reinit_frame_cache, but with the right arguments to be
|
||
callable as an sfunc. */
|
||
static void
|
||
reinit_frame_cache_sfunc (args, from_tty, c)
|
||
char *args;
|
||
int from_tty;
|
||
struct cmd_list_element *c;
|
||
{
|
||
reinit_frame_cache ();
|
||
}
|
||
|
||
void
|
||
_initialize_mips_tdep ()
|
||
{
|
||
struct cmd_list_element *c;
|
||
|
||
/* Let the user turn off floating point and set the fence post for
|
||
heuristic_proc_start. */
|
||
|
||
add_show_from_set
|
||
(add_set_cmd ("mipsfpu", class_support, var_boolean,
|
||
(char *) &mips_fpu,
|
||
"Set use of floating point coprocessor.\n\
|
||
Turn off to avoid using floating point instructions when calling functions\n\
|
||
or dealing with return values.", &setlist),
|
||
&showlist);
|
||
|
||
/* We really would like to have both "0" and "unlimited" work, but
|
||
command.c doesn't deal with that. So make it a var_zinteger
|
||
because the user can always use "999999" or some such for unlimited. */
|
||
c = add_set_cmd ("heuristic-fence-post", class_support, var_zinteger,
|
||
(char *) &heuristic_fence_post,
|
||
"\
|
||
Set the distance searched for the start of a function.\n\
|
||
If you are debugging a stripped executable, GDB needs to search through the\n\
|
||
program for the start of a function. This command sets the distance of the\n\
|
||
search. The only need to set it is when debugging a stripped executable.",
|
||
&setlist);
|
||
/* We need to throw away the frame cache when we set this, since it
|
||
might change our ability to get backtraces. */
|
||
c->function.sfunc = reinit_frame_cache_sfunc;
|
||
add_show_from_set (c, &showlist);
|
||
}
|