-/* Target-dependent code for the NEC MN10300 for GDB, the GNU debugger.
- Copyright 1996, Free Software Foundation, Inc.
+/* Target-dependent code for the Matsushita MN10300 for GDB, the GNU debugger.
+ Copyright 1996, 1997 Free Software Foundation, Inc.
This file is part of GDB.
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. */
-
-/* Contributed by Geoffrey Noer, noer@cygnus.com */
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "frame.h"
struct pifsr *pifsrs;
};
+static CORE_ADDR mn10300_scan_prologue PARAMS ((CORE_ADDR pc,
+ struct prologue_info *fs));
+\f
+/* Function: scan_prologue
+ Scan the prologue of the function that contains PC, and record what
+ we find in PI. PI->fsr must be zeroed by the called. Returns the
+ pc after the prologue. Note that the addresses saved in pi->fsr
+ are actually just frame relative (negative offsets from the frame
+ pointer). This is because we don't know the actual value of the
+ frame pointer yet. In some circumstances, the frame pointer can't
+ be determined till after we have scanned the prologue. */
+
static CORE_ADDR
mn10300_scan_prologue (pc, pi)
CORE_ADDR pc;
struct prologue_info *pi;
{
+ CORE_ADDR func_addr, prologue_end, current_pc;
+ struct pifsr *pifsr;
+ int fp_used;
+
+ printf("mn10300_scan_prologue start\n");
+
+ /* First, figure out the bounds of the prologue so that we can limit the
+ search to something reasonable. */
+
+ if (find_pc_partial_function (pc, NULL, &func_addr, NULL))
+ {
+ struct symtab_and_line sal;
+
+ sal = find_pc_line (func_addr, 0);
+
+ if (func_addr == entry_point_address ())
+ pi->start_function = 1;
+ else
+ pi->start_function = 0;
+
+#if 0
+ if (sal.line == 0)
+ prologue_end = pc;
+ else
+ prologue_end = sal.end;
+#else
+ prologue_end = pc;
+#endif
+ }
+ else
+ { /* We're in the boondocks */
+ func_addr = pc - 100;
+ prologue_end = pc;
+ }
+
+ prologue_end = min (prologue_end, pc);
+
+ /* Now, search the prologue looking for instructions that setup fp, save
+ rp, adjust sp and such. We also record the frame offset of any saved
+ registers. */
+
+ pi->frameoffset = 0;
+ pi->framereg = SP_REGNUM;
+ fp_used = 0;
+ pifsr = pi->pifsrs;
+
+ for (current_pc = func_addr; current_pc < prologue_end; current_pc += 2)
+ {
+ int insn;
+
+ insn = read_memory_unsigned_integer (current_pc, 2);
+
+ if ((insn & 0x07c0) == 0x0780 /* jarl or jr */
+ || (insn & 0xffe0) == 0x0060 /* jmp */
+ || (insn & 0x0780) == 0x0580) /* branch */
+ break; /* Ran into end of prologue */
+ if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240)) /* add <imm>,sp */
+ pi->frameoffset = ((insn & 0x1f) ^ 0x10) - 0x10;
+ else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM)) /* addi <imm>,sp,sp */
+ pi->frameoffset = read_memory_integer (current_pc + 2, 2);
+ else if (insn == ((FP_REGNUM << 11) | 0x0000 | 12)) /* mov r12,fp */
+ {
+ fp_used = 1;
+ pi->framereg = FP_REGNUM;
+ }
+ else if ((insn & 0x07ff) == (0x0760 | SP_REGNUM) /* st.w <reg>,<offset>[sp] */
+ || (fp_used
+ && (insn & 0x07ff) == (0x0760 | FP_REGNUM))) /* st.w <reg>,<offset>[fp] */
+ if (pifsr)
+ {
+ pifsr->framereg = insn & 0x1f;
+ pifsr->reg = (insn >> 11) & 0x1f; /* Extract <reg> */
+
+ pifsr->offset = read_memory_integer (current_pc + 2, 2) & ~1;
+
+ pifsr++;
+ }
+
+ if ((insn & 0x0780) >= 0x0600) /* Four byte instruction? */
+ current_pc += 2;
+ }
+
+ if (pifsr)
+ pifsr->framereg = 0; /* Tie off last entry */
+
+ printf("mn10300_scan_prologue end \n");
+
+ return current_pc;
}
+/* Function: init_extra_frame_info
+ Setup the frame's frame pointer, pc, and frame addresses for saved
+ registers. Most of the work is done in scan_prologue().
+
+ Note that when we are called for the last frame (currently active frame),
+ that fi->pc and fi->frame will already be setup. However, fi->frame will
+ be valid only if this routine uses FP. For previous frames, fi-frame will
+ always be correct (since that is derived from mn10300_frame_chain ()).
+
+ We can be called with the PC in the call dummy under two circumstances.
+ First, during normal backtracing, second, while figuring out the frame
+ pointer just prior to calling the target function (see run_stack_dummy). */
+
void
mn10300_init_extra_frame_info (fi)
struct frame_info *fi;
{
+ struct prologue_info pi;
+ struct pifsr pifsrs[NUM_REGS + 1], *pifsr;
+ int reg;
+
+ printf("mn10300_init_extra_frame_info start\n");
+
+ if (fi->next)
+ fi->pc = FRAME_SAVED_PC (fi->next);
+
+ memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs);
+
+ /* The call dummy doesn't save any registers on the stack, so we can return
+ now. */
+ if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
+ return;
+
+ pi.pifsrs = pifsrs;
+
+ mn10300_scan_prologue (fi->pc, &pi);
+
+ if (!fi->next && pi.framereg == SP_REGNUM)
+ fi->frame = read_register (pi.framereg) - pi.frameoffset;
+
+ for (pifsr = pifsrs; pifsr->framereg; pifsr++)
+ {
+ fi->fsr.regs[pifsr->reg] = pifsr->offset + fi->frame;
+
+ if (pifsr->framereg == SP_REGNUM)
+ fi->fsr.regs[pifsr->reg] += pi.frameoffset;
+ }
+
+ printf("mn10300_init_extra_frame_info end\n");
}
+/* Function: frame_chain
+ Figure out the frame prior to FI. Unfortunately, this involves
+ scanning the prologue of the caller, which will also be done
+ shortly by mn10300_init_extra_frame_info. For the dummy frame, we
+ just return the stack pointer that was in use at the time the
+ function call was made. */
+
CORE_ADDR
mn10300_frame_chain (fi)
struct frame_info *fi;
{
+ struct prologue_info pi;
+ CORE_ADDR callers_pc, fp;
+
+ printf("mn10300_frame_chain start\n");
+
+ /* First, find out who called us */
+ callers_pc = FRAME_SAVED_PC (fi);
+ /* If caller is a call-dummy, then our FP bears no relation to his FP! */
+ fp = mn10300_find_callers_reg (fi, FP_REGNUM);
+ if (PC_IN_CALL_DUMMY(callers_pc, fp, fp))
+ return fp; /* caller is call-dummy: return oldest value of FP */
+
+ /* Caller is NOT a call-dummy, so everything else should just work.
+ Even if THIS frame is a call-dummy! */
+ pi.pifsrs = NULL;
+
+ mn10300_scan_prologue (callers_pc, &pi);
+
+ printf("mn10300_frame_chain end\n");
+
+ if (pi.start_function)
+ return 0; /* Don't chain beyond the start function */
+
+ if (pi.framereg == FP_REGNUM)
+ return mn10300_find_callers_reg (fi, pi.framereg);
+
+ return fi->frame - pi.frameoffset;
}
+/* Function: find_callers_reg
+ Find REGNUM on the stack. Otherwise, it's in an active register.
+ One thing we might want to do here is to check REGNUM against the
+ clobber mask, and somehow flag it as invalid if it isn't saved on
+ the stack somewhere. This would provide a graceful failure mode
+ when trying to get the value of caller-saves registers for an inner
+ frame. */
+
CORE_ADDR
mn10300_find_callers_reg (fi, regnum)
struct frame_info *fi;
int regnum;
{
+ printf("mn10300_find_callers_reg\n");
+
+ for (; fi; fi = fi->next)
+ if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
+ return generic_read_register_dummy (fi->pc, fi->frame, regnum);
+ else if (fi->fsr.regs[regnum] != 0)
+ return read_memory_unsigned_integer (fi->fsr.regs[regnum],
+ REGISTER_RAW_SIZE(regnum));
+
+ return read_register (regnum);
}
+/* Function: skip_prologue
+ Return the address of the first code past the prologue of the function. */
+
CORE_ADDR
mn10300_skip_prologue (pc)
CORE_ADDR pc;
{
+ CORE_ADDR func_addr, func_end;
+
+ printf("mn10300_skip_prologue\n");
+
+ /* See what the symbol table says */
+
+ if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
+ {
+ struct symtab_and_line sal;
+
+ sal = find_pc_line (func_addr, 0);
+
+ if (sal.line != 0 && sal.end < func_end)
+ return sal.end;
+ else
+ /* Either there's no line info, or the line after the prologue is after
+ the end of the function. In this case, there probably isn't a
+ prologue. */
+ return pc;
+ }
+
+/* We can't find the start of this function, so there's nothing we can do. */
+ return pc;
}
/* Function: pop_frame
mn10300_pop_frame (frame)
struct frame_info *frame;
{
+ int regnum;
+
+ printf("mn10300_pop_frame start\n");
+
+ if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame))
+ generic_pop_dummy_frame ();
+ else
+ {
+ write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
+
+ for (regnum = 0; regnum < NUM_REGS; regnum++)
+ if (frame->fsr.regs[regnum] != 0)
+ write_register (regnum,
+ read_memory_unsigned_integer (frame->fsr.regs[regnum],
+ REGISTER_RAW_SIZE(regnum)));
+
+ write_register (SP_REGNUM, FRAME_FP (frame));
+ }
+
+ flush_cached_frames ();
+
+ printf("mn10300_pop_frame end\n");
}
+/* Function: push_arguments
+ Setup arguments for a call to the target. Arguments go in
+ order on the stack.
+*/
+
CORE_ADDR
mn10300_push_arguments (nargs, args, sp, struct_return, struct_addr)
int nargs;
unsigned char struct_return;
CORE_ADDR struct_addr;
{
+ int argnum = 0;
+ int len = 0;
+ int stack_offset = 0; /* copy args to this offset onto stack */
+
+ printf("mn10300_push_arguments start\n");
+
+ /* First, just for safety, make sure stack is aligned */
+ sp &= ~3;
+
+ /* Now make space on the stack for the args. */
+ for (argnum = 0; argnum < nargs; argnum++)
+ len += ((TYPE_LENGTH(VALUE_TYPE(args[argnum])) + 3) & ~3);
+
+ sp -= len;
+
+ /* Push all arguments onto the stack. */
+ for (argnum = 0; argnum < nargs; argnum++)
+ {
+ int len;
+ char *val;
+
+ if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT
+ && TYPE_LENGTH (VALUE_TYPE (*args)) > 8)
+ {
+ /* for now, pretend structs aren't special */
+ len = TYPE_LENGTH (VALUE_TYPE (*args));
+ val = (char *)VALUE_CONTENTS (*args);
+ }
+ else
+ {
+ len = TYPE_LENGTH (VALUE_TYPE (*args));
+ val = (char *)VALUE_CONTENTS (*args);
+ }
+
+ while (len > 0)
+ {
+ write_memory (sp + stack_offset, val, 4);
+
+ len -= 4;
+ val += 4;
+ stack_offset += 4;
+ }
+ args++;
+ }
+
+ printf("mn10300_push_arguments end\n");
+
+ return sp;
}
+/* Function: push_return_address (pc)
+ Set up the return address for the inferior function call.
+ Needed for targets where we don't actually execute a JSR/BSR instruction */
+
CORE_ADDR
mn10300_push_return_address (pc, sp)
CORE_ADDR pc;
CORE_ADDR sp;
{
+ printf("mn10300_push_return_address\n");
+
+ /* write_register (RP_REGNUM, CALL_DUMMY_ADDRESS ()); */
+ return sp;
}
+/* Function: frame_saved_pc
+ Find the caller of this frame. We do this by seeing if RP_REGNUM
+ is saved in the stack anywhere, otherwise we get it from the
+ registers. If the inner frame is a dummy frame, return its PC
+ instead of RP, because that's where "caller" of the dummy-frame
+ will be found. */
+
CORE_ADDR
mn10300_frame_saved_pc (fi)
struct frame_info *fi;
{
+ printf("mn10300_frame_saved_pc\n");
+
+/* if (PC_IN_CALL_DUMMY(fi->pc, fi->frame, fi->frame)) */
+ return generic_read_register_dummy(fi->pc, fi->frame, PC_REGNUM);
+/* else
+ return mn10300_find_callers_reg (fi, RP_REGNUM);
+*/
}
void
int regnum;
enum lval_type *lval;
{
+ printf("get_saved_register\n");
+
generic_get_saved_register (raw_buffer, optimized, addrp,
frame, regnum, lval);
}
+/* Function: fix_call_dummy
+ Pokes the callee function's address into the CALL_DUMMY assembly stub.
+ Assumes that the CALL_DUMMY looks like this:
+ jarl <offset24>, r31
+ trap
+ */
+
int
mn10300_fix_call_dummy (dummy, sp, fun, nargs, args, type, gcc_p)
char *dummy;
struct type *type;
int gcc_p;
{
+ long offset24;
+
+ printf("mn10300_fix_call_dummy start\n");
+
+ offset24 = (long) fun - (long) entry_point_address ();
+ offset24 &= 0x3fffff;
+ offset24 |= 0xff800000; /* jarl <offset24>, r31 */
+
+ store_unsigned_integer ((unsigned int *)&dummy[2], 2, offset24 & 0xffff);
+ store_unsigned_integer ((unsigned int *)&dummy[0], 2, offset24 >> 16);
+
+ printf("mn10300_fix_call_dummy end\n");
+
+ return 0;
}
void
_initialize_mn10300_tdep ()
{
+ printf("_initialize_mn10300_tdep\n");
+
tm_print_insn = print_insn_mn10300;
}
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