e5a2ac8b3f
struct frame to make it possible to use frame_saved_args in EXTRA_FRAME_INFO macro. * v850-tdep.c config/v850/tm-v850.h: Lotsa new functions and macros to make frame operations (such as backtrace) work.
254 lines
6.7 KiB
C
254 lines
6.7 KiB
C
/* Target-dependent code for the NEC V850 for GDB, the GNU debugger.
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Copyright 1986, 1996
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Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* ??? Support for calling functions from gdb in sparc64 is unfinished. */
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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 "obstack.h"
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#include "target.h"
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#include "value.h"
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#include "bfd.h"
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#include "gdb_string.h"
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#include "gdbcore.h"
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/* This function actually figures out the frame address for a given pc and
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sp. This is tricky on the v850 because we only use an explicit frame
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pointer when using alloca(). The only reliable way to get this info is to
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examine the prologue.
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*/
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void
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v850_init_extra_frame_info (fi)
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struct frame_info *fi;
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{
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struct symtab_and_line sal;
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CORE_ADDR func_addr, prologue_end, current_pc;
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int reg;
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int frameoffset;
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int framereg;
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if (fi->next)
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fi->pc = v850_find_callers_reg (fi->next, RP_REGNUM);
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/* First, figure out the bounds of the prologue so that we can limit the
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search to something reasonable. */
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if (find_pc_partial_function (fi->pc, NULL, &func_addr, NULL))
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{
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sal = find_pc_line (func_addr, 0);
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prologue_end = sal.end;
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}
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else
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prologue_end = func_addr + 100; /* We're in the boondocks */
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prologue_end = min (prologue_end, fi->pc);
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/* Now, search the prologue looking for instructions that setup fp, save
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rp, adjust sp and such. */
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framereg = SP_REGNUM;
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frameoffset = 0;
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memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs);
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for (current_pc = func_addr; current_pc < prologue_end; current_pc += 2)
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{
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int insn;
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insn = read_memory_integer (current_pc, 2);
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if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240)) /* add <imm>,sp */
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frameoffset = (insn & 0x1f) | ~0x1f;
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else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM)) /* addi <imm>,sp,sp */
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{
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current_pc += 2;
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frameoffset = read_memory_integer (current_pc, 2);
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}
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else if (insn == ((FP_REGNUM << 11) | 0x0000 | 12)) /* mov r12,r2 */
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framereg = FP_REGNUM; /* Setting up fp */
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else if ((insn & 0x07ff) == (0x0760 | SP_REGNUM)) /* st.w <reg>,<offset>[sp] */
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{
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reg = (insn >> 11) & 0x1f; /* Extract <reg> */
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current_pc += 2;
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insn = read_memory_integer (current_pc, 2) & ~1;
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fi->fsr.regs[reg] = insn + frameoffset;
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}
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else if ((insn & 0x07ff) == (0x0760 | FP_REGNUM)) /* st.w <reg>,<offset>[fp] */
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{
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reg = (insn >> 11) & 0x1f; /* Extract <reg> */
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current_pc += 2;
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insn = read_memory_integer (current_pc, 2) & ~1;
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fi->fsr.regs[reg] = insn;
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}
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}
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#if 0
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if (!fi->next)
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fi->frame = read_register (framereg);
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else
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if (framereg == SP_REGNUM)
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fi->frame = fi->next->frame;
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else
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fi->frame = v850_find_callers_reg (fi, framereg);
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if (framereg == SP_REGNUM)
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fi->frame -= frameoffset;
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#else
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if (!fi->next && framereg == SP_REGNUM)
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fi->frame = read_register (framereg) - frameoffset;
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#endif
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for (reg = 0; reg < NUM_REGS; reg++)
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if (fi->fsr.regs[reg] != 0)
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fi->fsr.regs[reg] += fi->frame;
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}
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/* Find the caller of this frame. We do this by seeing if RP_REGNUM is saved
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in the stack anywhere, otherwise we get it from the registers. */
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CORE_ADDR
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v850_find_callers_reg (fi, regnum)
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struct frame_info *fi;
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int regnum;
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{
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for (; fi; fi = fi->next)
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if (fi->fsr.regs[regnum] != 0)
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return read_memory_integer (fi->fsr.regs[regnum], 4);
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return read_register (regnum);
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}
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CORE_ADDR
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v850_frame_chain (fi)
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struct frame_info *fi;
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{
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CORE_ADDR callers_pc, callers_sp;
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struct frame_info temp_fi;
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CORE_ADDR func_addr, prologue_end, current_pc;
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int frameoffset;
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/* First, find out who called us */
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callers_pc = v850_find_callers_reg (fi, RP_REGNUM);
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/* Next, figure out where his prologue is. */
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if (find_pc_partial_function (callers_pc, NULL, &func_addr, NULL))
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{
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struct symtab_and_line sal;
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sal = find_pc_line (func_addr, 0);
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prologue_end = sal.end;
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}
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else
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prologue_end = func_addr + 100; /* We're in the boondocks */
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prologue_end = min (prologue_end, callers_pc);
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/* Now, figure out the frame location of the caller by examining his prologue.
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We're looking for either a load of the frame pointer register, or a stack
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adjustment. */
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frameoffset = 0;
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for (current_pc = func_addr; current_pc < prologue_end; current_pc += 2)
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{
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int insn;
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insn = read_memory_integer (current_pc, 2);
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if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240)) /* add <imm>,sp */
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frameoffset = (insn & 0x1f) | ~0x1f;
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else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM)) /* addi <imm>,sp,sp */
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{
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current_pc += 2;
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frameoffset = read_memory_integer (current_pc, 2);
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}
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else if (insn == ((FP_REGNUM << 11) | 0x0000 | 12)) /* mov r12,r2 */
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return v850_find_callers_reg (fi, FP_REGNUM); /* It's using a frame pointer reg */
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else if ((insn & 0x07ff) == (0x0760 | SP_REGNUM)) /* st.w <reg>,<offset>[sp] */
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current_pc += 2;
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else if ((insn & 0x07ff) == (0x0760 | FP_REGNUM)) /* st.w <reg>,<offset>[fp] */
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current_pc += 2;
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}
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return fi->frame - frameoffset;
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}
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CORE_ADDR
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v850_skip_prologue (pc)
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CORE_ADDR pc;
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{
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CORE_ADDR func_addr, func_end;
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/* See what the symbol table says */
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if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
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{
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struct symtab_and_line sal;
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sal = find_pc_line (func_addr, 0);
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if (sal.end < func_end)
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return sal.end;
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else
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/* The line after the prologue is after the end of the function. In
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this case, there probably isn't a prologue. */
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return pc;
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}
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/* We can't find the start of this function, so there's nothing we can do. */
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return pc;
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}
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struct frame_info *
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v850_pop_frame (frame)
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struct frame_info *frame;
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{
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int regnum;
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write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
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for (regnum = 0; regnum < NUM_REGS; regnum++)
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if (frame->fsr.regs[regnum] != 0)
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write_register (regnum, read_memory_integer (frame->fsr.regs[regnum], 4));
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write_register (SP_REGNUM, FRAME_FP (frame));
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flush_cached_frames ();
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return NULL;
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}
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void
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_initialize_sparc_tdep ()
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{
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tm_print_insn = print_insn_v850;
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}
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