Initial creation of sourceware repositorygdb-4_18-branchpoint

1 files changed, 552 insertions, 0 deletions

diff --git a/gdb/fr30-tdep.c b/gdb/fr30-tdep.c
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+/* Target-dependent code for the Fujitsu FR30.
+   Copyright 1999, 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"
+
+/* Function: pop_frame
+   This routine gets called when either the user uses the `return'
+   command, or the call dummy breakpoint gets hit.  */
+
+void
+fr30_pop_frame ()
+{
+  struct frame_info *frame = get_current_frame();
+  int regnum;
+  CORE_ADDR sp = read_register(SP_REGNUM);
+
+  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, sp + frame->framesize);
+    }
+  flush_cached_frames ();
+}
+
+/* Function: skip_prologue
+   Return the address of the first code past the prologue of the function.  */
+
+CORE_ADDR
+fr30_skip_prologue(CORE_ADDR pc)
+{
+  CORE_ADDR func_addr, func_end;
+
+  /* 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;
+	}
+    }
+
+/* Either we didn't find the start of this function (nothing we can do),
+   or there's no line info, or the line after the prologue is after
+   the end of the function (there probably isn't a prologue). */
+
+  return pc;
+}
+
+
+/* Function: push_arguments
+   Setup arguments and RP for a call to the target.  First four args
+   go in FIRST_ARGREG -> LAST_ARGREG, subsequent args go on stack...
+   Structs are passed by reference.  XXX not right now Z.R.
+   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 FIRST_ARGREG).
+
+   Stack space for the args has NOT been allocated: that job is up to us.
+*/
+
+CORE_ADDR
+fr30_push_arguments(nargs, args, sp, struct_return, struct_addr)
+     int         nargs;
+     value_ptr * args;
+     CORE_ADDR   sp;
+     int         struct_return;
+     CORE_ADDR   struct_addr;
+{
+  int argreg;
+  int argnum;
+  int stack_offset;
+  struct stack_arg {
+      char *val;
+      int len;
+      int offset;
+    };
+  struct stack_arg *stack_args =
+      (struct stack_arg*)alloca (nargs * sizeof (struct stack_arg));
+  int nstack_args = 0;
+
+  argreg = FIRST_ARGREG;
+
+  /* the struct_return pointer occupies the first parameter-passing reg */
+  if (struct_return)
+      write_register (argreg++, struct_addr);
+
+  stack_offset = 0;
+
+  /* Process args from left to right.  Store as many as allowed in
+	registers, save the rest to be pushed on the stack */
+  for(argnum = 0; argnum < nargs; argnum++)
+    {
+      char *         val;
+      value_ptr      arg = args[argnum];
+      struct type *  arg_type = check_typedef (VALUE_TYPE (arg));
+      struct type *  target_type = TYPE_TARGET_TYPE (arg_type);
+      int            len = TYPE_LENGTH (arg_type);
+      enum type_code typecode = TYPE_CODE (arg_type);
+      CORE_ADDR      regval;
+      int newarg;
+
+      val = (char *) VALUE_CONTENTS (arg);
+
+	{
+	  /* Copy the argument to general registers or the stack in
+	     register-sized pieces.  Large arguments are split between
+	     registers and stack.  */
+	  while (len > 0)
+	    {
+	      if (argreg <= LAST_ARGREG)
+		{
+	          int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE;
+		  regval = extract_address (val, partial_len);
+
+		  /* It's a simple argument being passed in a general
+		     register.  */
+		  write_register (argreg, regval);
+		  argreg++;
+	          len -= partial_len;
+	          val += partial_len;
+		}
+	      else
+		{
+		  /* keep for later pushing */
+		  stack_args[nstack_args].val = val;
+		  stack_args[nstack_args++].len = len;
+		  break;
+		}
+	    }
+	}
+    }
+    /* now do the real stack pushing, process args right to left */
+    while(nstack_args--)
+      {
+	sp -= stack_args[nstack_args].len;
+	write_memory(sp, stack_args[nstack_args].val,
+		stack_args[nstack_args].len);
+      }
+
+  /* Return adjusted stack pointer.  */
+  return sp;
+}
+
+_initialize_fr30_tdep()
+{
+	extern int print_insn_fr30(bfd_vma, disassemble_info *);
+
+	tm_print_insn = print_insn_fr30;
+}
+
+/* Function: check_prologue_cache
+   Check if prologue for this frame's PC has already been scanned.
+   If it has, copy the relevant information about that prologue and
+   return non-zero.  Otherwise do not copy anything and return zero.
+
+   The information saved in the cache includes:
+     * the frame register number;
+     * the size of the stack frame;
+     * the offsets of saved regs (relative to the old SP); and
+     * the offset from the stack pointer to the frame pointer
+
+   The cache contains only one entry, since this is adequate
+   for the typical sequence of prologue scan requests we get.
+   When performing a backtrace, GDB will usually ask to scan
+   the same function twice in a row (once to get the frame chain,
+   and once to fill in the extra frame information).
+*/
+
+static struct frame_info prologue_cache;
+
+static int
+check_prologue_cache (fi)
+     struct frame_info * fi;
+{
+  int i;
+
+  if (fi->pc == prologue_cache.pc)
+    {
+      fi->framereg = prologue_cache.framereg;
+      fi->framesize = prologue_cache.framesize;
+      fi->frameoffset = prologue_cache.frameoffset;
+      for (i = 0; i <= NUM_REGS; i++)
+	fi->fsr.regs[i] = prologue_cache.fsr.regs[i];
+      return 1;
+    }
+  else
+    return 0;
+}
+
+
+/* Function: save_prologue_cache
+   Copy the prologue information from fi to the prologue cache.
+*/
+
+static void
+save_prologue_cache (fi)
+     struct frame_info * fi;
+{
+  int i;
+
+  prologue_cache.pc          = fi->pc;
+  prologue_cache.framereg    = fi->framereg;
+  prologue_cache.framesize   = fi->framesize;
+  prologue_cache.frameoffset = fi->frameoffset;
+  
+  for (i = 0; i <= NUM_REGS; i++) {
+    prologue_cache.fsr.regs[i] = fi->fsr.regs[i];
+  }
+}
+
+
+/* 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 void
+fr30_scan_prologue (fi)
+     struct frame_info * fi;
+{
+  int sp_offset, fp_offset;
+  CORE_ADDR prologue_start, prologue_end, current_pc;
+
+  /* Check if this function is already in the cache of frame information. */
+  if (check_prologue_cache (fi))
+    return;
+
+  /* Assume there is no frame until proven otherwise.  */
+  fi->framereg    = SP_REGNUM;
+  fi->framesize   = 0;
+  fi->frameoffset = 0;
+
+  /* Find the function prologue.  If we can't find the function in
+     the symbol table, peek in the stack frame to find the PC.  */
+  if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
+    {
+      /* Assume the prologue is everything between the first instruction
+         in the function and the first source line.  */
+      struct symtab_and_line 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
+    {
+      /* XXX Z.R. What now??? The following is entirely bogus */
+      prologue_start = (read_memory_integer (fi->frame, 4) & 0x03fffffc) - 12;
+      prologue_end = prologue_start + 40;
+    }
+
+  /* Now search the prologue looking for instructions that set up the
+     frame pointer, adjust the stack pointer, and save registers.  */
+
+  sp_offset = fp_offset = 0;
+  for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2)
+    {
+      unsigned int insn;
+
+      insn = read_memory_unsigned_integer (current_pc, 2);
+
+      if ((insn & 0xfe00) == 0x8e00)			/* stm0 or stm1 */
+	{
+	  int reg, mask = insn & 0xff;
+
+	  /* scan in one sweep - create virtual 16-bit mask from either insn's mask */
+          if((insn & 0x0100) == 0)
+	    {
+	      mask <<= 8;  /* stm0 - move to upper byte in virtual mask */
+	    }
+
+	  /* Calculate offsets of saved registers (to be turned later into addresses). */
+	  for (reg = R4_REGNUM; reg <= R11_REGNUM; reg++)
+	    if (mask & (1 << (15 - reg)))
+	      {
+		sp_offset -= 4;
+		fi->fsr.regs[reg] = sp_offset;
+	      }
+	}
+      else if((insn & 0xfff0) == 0x1700)		/* st rx,@-r15 */
+        {
+	  int reg = insn & 0xf;
+
+	  sp_offset -= 4;
+	  fi->fsr.regs[reg] = sp_offset;
+	}
+      else if((insn & 0xff00) == 0x0f00)		/* enter */
+        {
+	  fp_offset = fi->fsr.regs[FP_REGNUM] = sp_offset - 4;
+	  sp_offset -= 4 * (insn & 0xff);
+	  fi->framereg = FP_REGNUM;
+	}
+      else if(insn == 0x1781)				/* st rp,@-sp */
+	{
+		sp_offset -= 4;
+		fi->fsr.regs[RP_REGNUM] = sp_offset;
+	}
+      else if(insn == 0x170e)				/* st fp,@-sp */
+	{
+		sp_offset -= 4;
+		fi->fsr.regs[FP_REGNUM] = sp_offset;
+	}
+      else if(insn == 0x8bfe)				/* mov sp,fp */
+	{
+	  fi->framereg = FP_REGNUM;
+	}
+      else if((insn & 0xff00) == 0xa300)		/* addsp xx */
+	{
+	  sp_offset += 4 * (signed char)(insn & 0xff);
+	}
+      else if((insn & 0xff0f) == 0x9b00 &&		/* ldi:20 xx,r0 */
+	read_memory_unsigned_integer(current_pc+4, 2)
+	  == 0xac0f)					/* sub r0,sp */
+	{
+	  /* large stack adjustment */
+	  sp_offset -= (((insn & 0xf0) << 12) | read_memory_unsigned_integer(current_pc+2, 2));
+	  current_pc += 4;
+	}
+      else if(insn == 0x9f80 &&				/* ldi:32 xx,r0 */
+	read_memory_unsigned_integer(current_pc+6, 2)
+	  == 0xac0f)					/* sub r0,sp */
+	{
+	  /* large stack adjustment */
+	  sp_offset -=
+		(read_memory_unsigned_integer(current_pc+2, 2) << 16 |
+			read_memory_unsigned_integer(current_pc+4, 2));
+	  current_pc += 6;
+	}
+    }
+
+  /* The frame size is just the negative of the offset (from the original SP)
+     of the last thing thing we pushed on the stack.  The frame offset is
+     [new FP] - [new SP].  */
+  fi->framesize = -sp_offset;
+  fi->frameoffset = fp_offset - sp_offset;
+  
+  save_prologue_cache (fi);
+}
+
+/* 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 fr30_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
+fr30_init_extra_frame_info (fi)
+     struct frame_info * fi;
+{
+  int reg;
+
+  if (fi->next)
+    fi->pc = FRAME_SAVED_PC (fi->next);
+
+  memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs);
+
+  if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
+    {
+      /* We need to setup fi->frame here because run_stack_dummy gets it wrong
+	 by assuming it's always FP.  */
+      fi->frame       = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM);
+      fi->framesize   = 0;
+      fi->frameoffset = 0;
+      return;
+    }
+      fr30_scan_prologue (fi);
+
+      if (!fi->next)			/* this is the innermost frame? */
+	fi->frame = read_register (fi->framereg);
+      else			 	/* not the innermost frame */
+	/* If we have an FP,  the callee saved it. */
+	if (fi->framereg == FP_REGNUM)
+	  if (fi->next->fsr.regs[fi->framereg] != 0)
+	    fi->frame = read_memory_integer (fi->next->fsr.regs[fi->framereg],
+					     4);
+      /* Calculate actual addresses of saved registers using offsets determined
+         by fr30_scan_prologue.  */
+      for (reg = 0; reg < NUM_REGS; reg++)
+	if (fi->fsr.regs[reg] != 0) {
+	  fi->fsr.regs[reg] += fi->frame + fi->framesize - fi->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
+fr30_find_callers_reg (fi, regnum)
+     struct frame_info *fi;
+     int regnum;
+{
+  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: 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 fr30_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
+fr30_frame_chain (fi)
+     struct frame_info * fi;
+{
+  CORE_ADDR fn_start, callers_pc, fp;
+  struct frame_info caller_fi;
+  int framereg;
+
+  /* is this a dummy frame? */
+  if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
+    return fi->frame;	/* dummy frame same as caller's frame */
+
+  /* is caller-of-this a dummy frame? */
+  callers_pc = FRAME_SAVED_PC(fi);  /* find out who called us: */
+  fp = fr30_find_callers_reg (fi, FP_REGNUM);
+  if (PC_IN_CALL_DUMMY (callers_pc, fp, fp))	
+    return fp;		/* dummy frame's frame may bear no relation to ours */
+
+  if (find_pc_partial_function (fi->pc, 0, &fn_start, 0))
+    if (fn_start == entry_point_address ())
+      return 0;		/* in _start fn, don't chain further */
+
+  framereg = fi->framereg;
+
+  /* If the caller is the startup code, we're at the end of the chain.  */
+  if (find_pc_partial_function (callers_pc, 0, &fn_start, 0))
+    if (fn_start == entry_point_address ())
+      return 0;
+
+  memset (& caller_fi, 0, sizeof (caller_fi));
+  caller_fi.pc = callers_pc;
+  fr30_scan_prologue (& caller_fi);
+  framereg = caller_fi.framereg;
+
+  /* If the caller used a frame register, return its value.
+     Otherwise, return the caller's stack pointer.  */
+  if (framereg == FP_REGNUM)
+    return fr30_find_callers_reg (fi, framereg);
+  else
+    return fi->frame + fi->framesize;
+}
+
+/* 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
+fr30_frame_saved_pc (fi)
+     struct frame_info *fi;
+{
+  if (PC_IN_CALL_DUMMY(fi->pc, fi->frame, fi->frame))
+    return generic_read_register_dummy(fi->pc, fi->frame, PC_REGNUM);
+  else
+    return fr30_find_callers_reg (fi, RP_REGNUM);
+}
+
+/* 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
+fr30_fix_call_dummy (dummy, sp, fun, nargs, args, type, gcc_p)
+     char *dummy;
+     CORE_ADDR sp;
+     CORE_ADDR fun;
+     int nargs;
+     value_ptr *args;
+     struct type *type;
+     int gcc_p;
+{
+  long offset24;
+
+  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);
+  return 0;
+}