-#include <stdio.h>
+/* Target-machine dependent code for Hitachi H8/300, for GDB.
+ Copyright (C) 1988, 1990, 1991 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/*
+ Contributed by Steve Chamberlain
+ sac@cygnus.com
+ */
+
#include "defs.h"
+#include "frame.h"
+#include "obstack.h"
+#include "symtab.h"
+#define UNSIGNED_SHORT(X) ((X) & 0xffff)
/* an easy to debug H8 stack frame looks like:
0x6df2 push r2
subs r5,sp
*/
+
#define IS_PUSH(x) ((x & 0xff00)==0x6d00)
+#define IS_MOVE_FP(x) (x == 0x0d76)
+#define IS_MOV_SP_FP(x) (x == 0x0d76)
+#define IS_SUB2_SP(x) (x==0x1b87)
+#define IS_MOVK_R5(x) (x==0x7905)
+CORE_ADDR examine_prologue();
+
+void frame_find_saved_regs ();
CORE_ADDR h8300_skip_prologue(start_pc)
CORE_ADDR start_pc;
{
+
/* Skip past all push insns */
short int w;
- w = read_memory_integer(start_pc, 2);
+ w = read_memory_short(start_pc);
while (IS_PUSH(w))
{
start_pc+=2;
- w = read_memory_integer(start_pc, 2);
+ w = read_memory_short(start_pc);
}
-return start_pc;
-
-}
-h8300_pop_frame()
-{
- printf("pop frame\n");
+ /* Skip past a move to FP */
+ if (IS_MOVE_FP(w)) {
+ start_pc +=2 ;
+ w = read_memory_short(start_pc);
+ }
+
+ return start_pc;
}
+
int
print_insn(memaddr, stream)
CORE_ADDR memaddr;
/* Nothing is bigger than 8 bytes */
char data[8];
read_memory (memaddr, data, sizeof(data));
- return print_insn_h8300(memaddr, data , stream);
-
-
+ return print_insn_h8300(memaddr, data, stream);
}
+/* 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 us, the frame address is its stack pointer value, so we look up
+ the function prologue to determine the caller's sp value, and return it. */
+
+FRAME_ADDR
+FRAME_CHAIN (thisframe)
+ FRAME thisframe;
+{
+
+ frame_find_saved_regs (thisframe, (struct frame_saved_regs *) 0);
+ return thisframe->fsr->regs[SP_REGNUM];
+}
+
- FRAME_CHAIN()
- {
-
- printf("Frame chain\n");
-
- }
-
+
+/* Put here the code to store, into a struct frame_saved_regs,
+ the addresses of the saved registers of frame described by FRAME_INFO.
+ This includes special registers such as pc and fp saved in special
+ ways in the stack frame. sp is even more special:
+ the address we return for it IS the sp for the next frame.
+
+ We cache the result of doing this in the frame_cache_obstack, since
+ it is fairly expensive. */
+
+void
+frame_find_saved_regs (fi, fsr)
+ struct frame_info *fi;
+ struct frame_saved_regs *fsr;
+{
+ register CORE_ADDR next_addr;
+ register CORE_ADDR *saved_regs;
+ register int regnum;
+ register struct frame_saved_regs *cache_fsr;
+ extern struct obstack frame_cache_obstack;
+ CORE_ADDR ip;
+ struct symtab_and_line sal;
+ CORE_ADDR limit;
+
+ if (!fi->fsr)
+ {
+ cache_fsr = (struct frame_saved_regs *)
+ obstack_alloc (&frame_cache_obstack,
+ sizeof (struct frame_saved_regs));
+ bzero (cache_fsr, sizeof (struct frame_saved_regs));
+ fi->fsr = cache_fsr;
+
+ /* Find the start and end of the function prologue. If the PC
+ is in the function prologue, we only consider the part that
+ has executed already. */
+
+ ip = get_pc_function_start (fi->pc);
+ sal = find_pc_line (ip, 0);
+ limit = (sal.end && sal.end < fi->pc) ? sal.end: fi->pc;
+
+ /* This will fill in fields in *fi as well as in cache_fsr. */
+ examine_prologue (ip, limit, fi->frame, cache_fsr, fi);
+ }
+
+ if (fsr)
+ *fsr = *fi->fsr;
+}
+
+/* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
+ is not the address of a valid instruction, the address of the next
+ instruction beyond ADDR otherwise. *PWORD1 receives the first word
+ of the instruction.*/
+
+
+CORE_ADDR
+NEXT_PROLOGUE_INSN(addr, lim, pword1)
+CORE_ADDR addr;
+CORE_ADDR lim;
+short *pword1;
+{
+ if (addr < lim+8)
+ {
+ read_memory (addr, pword1, sizeof(*pword1));
+ SWAP_TARGET_AND_HOST (pword1, sizeof (short));
+ return addr + 2;
+ }
+
+ return 0;
+
+}
+
+/* Examine the prologue of a function. `ip' points to the first instruction.
+ `limit' is the limit of the prologue (e.g. the addr of the first
+ linenumber, or perhaps the program counter if we're stepping through).
+ `frame_sp' is the stack pointer value in use in this frame.
+ `fsr' is a pointer to a frame_saved_regs structure into which we put
+ info about the registers saved by this frame.
+ `fi' is a struct frame_info pointer; we fill in various fields in it
+ to reflect the offsets of the arg pointer and the locals pointer. */
+
+/* We will find two sorts of prologue, framefull and non framefull:
+
+ push r2
+ push r3
+ push fp
+ mov sp,fp
+ stack_ad
+
+ and
+ push x
+ push y
+ stack_ad
+
+*/
+
+static CORE_ADDR
+examine_prologue (ip, limit, after_prolog_fp, fsr, fi)
+ register CORE_ADDR ip;
+ register CORE_ADDR limit;
+ FRAME_ADDR after_prolog_fp;
+ struct frame_saved_regs *fsr;
+ struct frame_info *fi;
+{
+ register CORE_ADDR next_ip;
+ int r;
+ int i;
+ int have_fp = 0;
+
+ register int src;
+ register struct pic_prologue_code *pcode;
+ INSN_WORD insn_word;
+ int size, offset;
+ unsigned int reg_save_depth = 2; /* Number of things pushed onto
+ stack, starts at 2, 'cause the
+ PC is already there */
+
+ unsigned int auto_depth = 0; /* Number of bytes of autos */
+
+ char in_frame[NUM_REGS]; /* One for each reg */
+
+ memset(in_frame, 1, NUM_REGS);
+
+ if (after_prolog_fp == 0) {
+ after_prolog_fp = read_register(SP_REGNUM);
+ }
+ if (ip == 0 || ip & ~0xffff) return 0;
+
+ next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word);
+
+ /* Skip over any push instructions, and remember where they were saved */
+
+
+ while (next_ip && IS_PUSH(insn_word))
+ {
+ ip = next_ip;
+ in_frame[insn_word & 0x7] = reg_save_depth;
+ next_ip = NEXT_PROLOGUE_INSN(ip, limit, &insn_word);
+ reg_save_depth +=2;
+
+ }
+
+
+ /* Is this a move into the fp */
+ if (next_ip && IS_MOV_SP_FP(insn_word))
+ {
+ ip = next_ip;
+ next_ip = NEXT_PROLOGUE_INSN(ip, limit, &insn_word);
+ have_fp = 1;
+
+ }
+
+
+ /* Skip over any stack adjustment, happens either with a number of
+ sub#2,sp or a mov #x,r5 sub r5,sp */
+
+
+ if (next_ip && IS_SUB2_SP(insn_word))
+ {
+ while (next_ip && IS_SUB2_SP(insn_word))
+ {
+ auto_depth +=2 ;
+ ip = next_ip;
+ next_ip = NEXT_PROLOGUE_INSN(ip, limit, &insn_word);
+ }
+ }
+ else
+ {
+ if (next_ip && IS_MOVK_R5(insn_word))
+ {
+ ip = next_ip;
+ next_ip = NEXT_PROLOGUE_INSN(ip, limit, &insn_word);
+ auto_depth += insn_word;
+ ip +=4;
+
+ }
+ }
+
+
+
+ /* The args are always reffed based from the stack pointer */
+ fi->args_pointer = after_prolog_fp - auto_depth;
+ /* Locals are always reffed based from the fp */
+ fi->locals_pointer = after_prolog_fp ;
+ /* The PC is at a known place */
+ fi->from_pc = read_memory_short(after_prolog_fp + reg_save_depth-2 );
+
+
+ /* Rememeber any others too */
+
+ in_frame[PC_REGNUM] = 0;
+
+ for (r = 0; r < NUM_REGS; r++)
+ {
+ if (in_frame[r] != 1)
+ {
+ fsr->regs[r] = after_prolog_fp + reg_save_depth - in_frame[r] -2;
+ }
+ else
+ {
+ fsr->regs[r] = 0;
+ }
+ }
+ if (have_fp)
+ /* We keep the old FP in the SP spot */
+ fsr->regs[SP_REGNUM] = (read_memory_short(fsr->regs[6])) ;
+ else
+ fsr->regs[SP_REGNUM] = after_prolog_fp + reg_save_depth;
+
+ return (ip);
+}
+
+void
+init_extra_frame_info (fromleaf, fi)
+ int fromleaf;
+ struct frame_info *fi;
+{
+ fi->fsr = 0; /* Not yet allocated */
+ fi->args_pointer = 0; /* Unknown */
+ fi->locals_pointer = 0; /* Unknown */
+ fi->from_pc = 0;
+
+}
+/* Return the saved PC from this frame.
+
+ If the frame has a memory copy of SRP_REGNUM, use that. If not,
+ just use the register SRP_REGNUM itself. */
+
+CORE_ADDR
+frame_saved_pc (frame)
+FRAME frame;
+
+{
+ return frame->from_pc;
+}
+
+
+CORE_ADDR
+frame_locals_address (fi)
+ struct frame_info *fi;
+{
+ if (!fi->locals_pointer)
+ {
+ struct frame_saved_regs ignore;
+ get_frame_saved_regs(fi, &ignore);
+
+ }
+ return fi->locals_pointer;
+}
+
+/* Return the address of the argument block for the frame
+ described by FI. Returns 0 if the address is unknown. */
+
+CORE_ADDR
+frame_args_address (fi)
+ struct frame_info *fi;
+{
+ if (!fi->args_pointer)
+ {
+ struct frame_saved_regs ignore;
+ get_frame_saved_regs(fi, &ignore);
+
+ }
+
+ return fi->args_pointer;
+}
+
+
+void h8300_pop_frame()
+{
+ unsigned regnum;
+ struct frame_saved_regs fsr;
+ struct frame_info *fi;
+
+ FRAME frame = get_current_frame();
+ fi = get_frame_info(frame);
+ get_frame_saved_regs(fi, &fsr);
+
+ for (regnum = 0; regnum < NUM_REGS; regnum ++)
+ {
+ if(fsr.regs[regnum])
+ {
+ write_register(regnum, read_memory_short (fsr.regs[regnum]));
+ }
+
+ flush_cached_frames();
+ set_current_frame(create_new_frame(read_register(FP_REGNUM),
+ read_pc()));
+
+ }
+
+}
projects / deliverable / binutils-gdb.git / blobdiff