+/* Target-dependent code for the Mitsubishi m32r for GDB, the GNU debugger.
+ Copyright 1996, 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 "inferior.h"
+#include "obstack.h"
+#include "target.h"
+#include "value.h"
+#include "bfd.h"
+#include "gdb_string.h"
+#include "gdbcore.h"
+#include "symfile.h"
+
+struct dummy_frame
+{
+ struct dummy_frame *next;
+
+ CORE_ADDR fp;
+ CORE_ADDR sp;
+ CORE_ADDR rp;
+ CORE_ADDR pc;
+};
+
+void
+m32r_frame_find_saved_regs PARAMS ((struct frame_info *fi,
+ struct frame_saved_regs *regaddr))
+{
+ *regaddr = fi->fsr;
+}
+
+static struct dummy_frame *dummy_frame_stack = NULL;
+
+/* Find end of function prologue */
+
+CORE_ADDR
+m32r_skip_prologue (pc)
+ CORE_ADDR pc;
+{
+ CORE_ADDR func_addr, func_end;
+ struct symtab_and_line sal;
+
+ /* See what the symbol table says */
+
+ if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
+ {
+ 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;
+}
+
+/* This function decodes the target function prologue to determine
+ 1) the size of the stack frame, and 2) which registers are saved on it.
+ It saves the offsets of saved regs in the frame_saved_regs argument,
+ and returns the frame size.
+*/
+
+static unsigned long
+m32r_scan_prologue (fi, fsr)
+ struct frame_info *fi;
+ struct frame_saved_regs *fsr;
+{
+ struct symtab_and_line sal;
+ CORE_ADDR prologue_start, prologue_end, current_pc;
+ unsigned long framesize;
+
+ /* this code essentially duplicates skip_prologue,
+ but we need the start address below. */
+
+ if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
+ {
+ sal = find_pc_line (prologue_start, 0);
+
+ if (sal.line == 0) /* no line info, use current PC */
+ prologue_end = fi->pc;
+ else if (sal.end < prologue_end) /* next line begins after fn end */
+ prologue_end = sal.end; /* (probably means no prologue) */
+ }
+ else
+ prologue_end = prologue_start + 100; /* We're in the boondocks */
+
+ prologue_end = min (prologue_end, fi->pc);
+
+ /* Now, search the prologue looking for instructions that setup fp, save
+ rp (and other regs), adjust sp and such. */
+
+ framesize = 0;
+ memset (fsr->regs, '\000', sizeof fsr->regs);
+
+ for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2)
+ {
+ int insn;
+ int regno;
+
+ insn = read_memory_unsigned_integer (current_pc, 2);
+ if (insn & 0x80) /* Four byte instruction? */
+ current_pc += 2;
+
+ if ((insn & 0xf0ff) == 0x207f) { /* st reg, @-sp */
+ framesize += 4;
+ regno = ((insn >> 8) & 0xf);
+ fsr->regs[regno] = framesize;
+ }
+ else if ((insn >> 8) == 0x4f) { /* addi sp */
+ framesize += -((char) (insn & 0xff)); /* offset */
+ break; /* end of stack adjustments */
+ }
+ }
+ return framesize;
+}
+
+/* This function actually figures out the frame address for a given pc and
+ sp. This is tricky on the v850 because we only use an explicit frame
+ pointer when using alloca(). The only reliable way to get this info is to
+ examine the prologue.
+*/
+
+void
+m32r_init_extra_frame_info (fi)
+ struct frame_info *fi;
+{
+ int reg;
+ int framesize;
+
+ if (fi->next)
+ fi->pc = FRAME_SAVED_PC (fi->next);
+
+ framesize = m32r_scan_prologue (fi, &fi->fsr);
+
+ if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL))
+ fi->frame = dummy_frame_stack->sp;
+ else if (!fi->next)
+ fi->frame = read_register (SP_REGNUM);
+
+ for (reg = 0; reg < NUM_REGS; reg++)
+ if (fi->fsr.regs[reg] != 0)
+ fi->fsr.regs[reg] = fi->frame + framesize - fi->fsr.regs[reg];
+}
+
+/* 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. */
+
+CORE_ADDR
+m32r_find_callers_reg (fi, regnum)
+ struct frame_info *fi;
+ int regnum;
+{
+#if 0
+ /* XXX - Won't work if multiple dummy frames are active */
+ if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL))
+ switch (regnum)
+ {
+ case SP_REGNUM:
+ return dummy_frame_stack->sp;
+ break;
+ case FP_REGNUM:
+ return dummy_frame_stack->fp;
+ break;
+ case RP_REGNUM:
+ return dummy_frame_stack->pc;
+ break;
+ case PC_REGNUM:
+ return dummy_frame_stack->pc;
+ break;
+ }
+
+#endif
+ for (; fi; fi = fi->next)
+ if (fi->fsr.regs[regnum] != 0)
+ return read_memory_integer (fi->fsr.regs[regnum], 4);
+ return read_register (regnum);
+}
+
+/* Given a GDB frame, determine the address of the calling function's frame.
+ This will be used to create a new GDB frame struct, and then
+ INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
+ For m32r, simply get the saved FP off the stack.
+ */
+
+CORE_ADDR
+m32r_frame_chain (fi)
+ struct frame_info *fi;
+{
+ CORE_ADDR saved_fp = fi->fsr.regs[FP_REGNUM];
+
+ if (saved_fp == 0)
+ return 0; /* frameless assembly language fn (such as _start) */
+
+ return read_memory_integer (saved_fp, 4);
+}
+
+/* All we do here is record SP and FP on the call dummy stack */
+
+void
+m32r_push_dummy_frame ()
+{
+ struct dummy_frame *dummy_frame;
+
+ dummy_frame = xmalloc (sizeof (struct dummy_frame));
+
+ dummy_frame->fp = read_register (FP_REGNUM);
+ dummy_frame->sp = read_register (SP_REGNUM);
+ dummy_frame->rp = read_register (RP_REGNUM);
+ dummy_frame->pc = read_register (PC_REGNUM);
+ dummy_frame->next = dummy_frame_stack;
+ dummy_frame_stack = dummy_frame;
+}
+
+/*
+ * MISSING FUNCTION HEADER COMMENT
+ */
+
+int
+m32r_pc_in_call_dummy (pc)
+ CORE_ADDR pc;
+{
+ return dummy_frame_stack
+ && pc >= CALL_DUMMY_ADDRESS ()
+ && pc <= CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK;
+}
+
+/* Discard from the stack the innermost frame,
+ restoring all saved registers. */
+
+struct frame_info *
+m32r_pop_frame (frame)
+ struct frame_info *frame;
+{
+ int regnum;
+
+#if 0
+ if (PC_IN_CALL_DUMMY (frame->pc, NULL, NULL))
+ {
+ struct dummy_frame *dummy_frame;
+
+ dummy_frame = dummy_frame_stack;
+ if (!dummy_frame)
+ error ("Can't pop dummy frame!");
+
+ dummy_frame_stack = dummy_frame->next;
+
+ write_register (FP_REGNUM, dummy_frame->fp);
+ write_register (SP_REGNUM, dummy_frame->sp);
+ write_register (RP_REGNUM, dummy_frame->rp);
+ write_register (PC_REGNUM, dummy_frame->pc);
+
+ free (dummy_frame);
+
+ flush_cached_frames ();
+
+ return NULL;
+ }
+
+#endif
+ 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_integer (frame->fsr.regs[regnum], 4));
+
+ write_register (SP_REGNUM, read_register (FP_REGNUM));
+ if (read_register (PSW_REGNUM) & 0x80)
+ write_register (SPU_REGNUM, read_register (SP_REGNUM));
+ else
+ write_register (SPI_REGNUM, read_register (SP_REGNUM));
+ /* registers_changed (); */
+ flush_cached_frames ();
+
+ return NULL;
+}
+
+/* Put arguments in the right places, and setup return address register (RP) to
+ point at a convenient place to put a breakpoint. First four args go in
+ R6->R9, subsequent args go into sp + 16 -> sp + ... Structs are passed by
+ reference. 64 bit quantities (doubles and long longs) may be split between
+ the regs and the stack. When calling a function that returns a struct, a
+ pointer to the struct is passed in as a secret first argument (always in R6).
+
+ By the time we get here, stack space has been allocated for the args, but
+ not for the struct return pointer. */
+
+CORE_ADDR
+m32r_push_arguments (nargs, args, sp, struct_return, struct_addr)
+ int nargs;
+ value_ptr *args;
+ CORE_ADDR sp;
+ unsigned char struct_return;
+ CORE_ADDR struct_addr;
+{
+ int argreg;
+ int argnum;
+
+ argreg = ARG0_REGNUM;
+
+#if 0
+ if (struct_return)
+ {
+ write_register (argreg++, struct_addr);
+ sp -= 4;
+ }
+
+ for (argnum = 0; argnum < nargs; argnum++)
+ {
+ int len;
+ char *val;
+ char valbuf[4];
+
+ if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT
+ && TYPE_LENGTH (VALUE_TYPE (*args)) > 8)
+ {
+ store_address (valbuf, 4, VALUE_ADDRESS (*args));
+ len = 4;
+ val = valbuf;
+ }
+ else
+ {
+ len = TYPE_LENGTH (VALUE_TYPE (*args));
+ val = (char *)VALUE_CONTENTS (*args);
+ }
+
+ while (len > 0)
+ if (argreg <= ARGLAST_REGNUM)
+ {
+ CORE_ADDR regval;
+
+ regval = extract_address (val, REGISTER_RAW_SIZE (argreg));
+ write_register (argreg, regval);
+
+ len -= REGISTER_RAW_SIZE (argreg);
+ val += REGISTER_RAW_SIZE (argreg);
+ argreg++;
+ }
+ else
+ {
+ write_memory (sp + argnum * 4, val, 4);
+
+ len -= 4;
+ val += 4;
+ }
+ args++;
+ }
+
+ write_register (RP_REGNUM, entry_point_address ());
+
+#endif
+ return sp;
+}
+\f
+void
+_initialize_m32r_tdep ()
+{
+ tm_print_insn = print_insn_m32r;
+}