* findvar.c (value_of_register, value_from_register),

[deliverable/binutils-gdb.git] / gdb / config / mips / tm-mips.h

/* Definitions to make GDB run on a mips box under 4.3bsd.
   Copyright 1986, 1987, 1989, 1991, 1992, 1993 Free Software Foundation, Inc.
   Contributed by Per Bothner (bothner@cs.wisc.edu) at U.Wisconsin
   and by Alessandro Forin (af@cs.cmu.edu) at CMU..

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.  */

#include <bfd.h>
#include "coff/sym.h"		/* Needed for PDR below.  */
#include "coff/symconst.h"

#if !defined (TARGET_BYTE_ORDER)
#define TARGET_BYTE_ORDER LITTLE_ENDIAN
#endif

/* Floating point is IEEE compliant */
#define IEEE_FLOAT

/* Some MIPS boards are provided both with and without a floating
   point coprocessor; we provide a user settable variable to tell gdb
   whether there is one or not.  */
extern int mips_fpu;

/* Offset from address of function to start of its code.
   Zero on most machines.  */

#define FUNCTION_START_OFFSET 0

/* Advance PC across any function entry prologue instructions
   to reach some "real" code.  */

#define SKIP_PROLOGUE(pc)	pc = mips_skip_prologue (pc, 0)
extern CORE_ADDR mips_skip_prologue PARAMS ((CORE_ADDR addr, int lenient));

/* Immediately after a function call, return the saved pc.
   Can't always go through the frames for this because on some machines
   the new frame is not set up until the new function executes
   some instructions.  */

#define SAVED_PC_AFTER_CALL(frame)	read_register(RA_REGNUM)

/* Are we currently handling a signal */

#define IN_SIGTRAMP(pc, name)	in_sigtramp(pc, name)

/* Stack grows downward.  */

#define INNER_THAN <

#define BIG_ENDIAN 4321
#if TARGET_BYTE_ORDER == BIG_ENDIAN
#define BREAKPOINT {0, 0x5, 0, 0xd}
#else
#define BREAKPOINT {0xd, 0, 0x5, 0}
#endif

/* Amount PC must be decremented by after a breakpoint.
   This is often the number of bytes in BREAKPOINT
   but not always.  */

#define DECR_PC_AFTER_BREAK 0

/* Nonzero if instruction at PC is a return instruction. "j ra" on mips. */

#define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 4) == 0x3e00008)

/* This is taken care of in print_floating [IEEE_FLOAT].  */

#define INVALID_FLOAT(p,l) 0

/* Say how long (all) registers are.  */

#define REGISTER_TYPE long

/* Number of machine registers */

#define NUM_REGS 80

/* Initializer for an array of names of registers.
   There should be NUM_REGS strings in this initializer.  */

#define REGISTER_NAMES 	\
    {	"zero",	"at",	"v0",	"v1",	"a0",	"a1",	"a2",	"a3", \
	"t0",	"t1",	"t2",	"t3",	"t4",	"t5",	"t6",	"t7", \
	"s0",	"s1",	"s2",	"s3",	"s4",	"s5",	"s6",	"s7", \
	"t8",	"t9",	"k0",	"k1",	"gp",	"sp",	"s8",	"ra", \
	"sr",	"lo",	"hi",	"bad",	"cause","pc",    \
	"f0",   "f1",   "f2",   "f3",   "f4",   "f5",   "f6",   "f7", \
	"f8",   "f9",   "f10",  "f11",  "f12",  "f13",  "f14",  "f15", \
	"f16",  "f17",  "f18",  "f19",  "f20",  "f21",  "f22",  "f23",\
	"f24",  "f25",  "f26",  "f27",  "f28",  "f29",  "f30",  "f31",\
	"fsr",  "fir",  "fp",   "inx",  "rand", "tlblo","ctxt", "tlbhi",\
	"epc",  "prid"\
    }

/* Register numbers of various important registers.
   Note that some of these values are "real" register numbers,
   and correspond to the general registers of the machine,
   and some are "phony" register numbers which are too large
   to be actual register numbers as far as the user is concerned
   but do serve to get the desired values when passed to read_register.  */

#define ZERO_REGNUM 0		/* read-only register, always 0 */
#define V0_REGNUM 2		/* Function integer return value */
#define A0_REGNUM 4		/* Loc of first arg during a subr call */
#define SP_REGNUM 29		/* Contains address of top of stack */
#define RA_REGNUM 31		/* Contains return address value */
#define PS_REGNUM 32		/* Contains processor status */
#define HI_REGNUM 34            /* Multiple/divide temp */
#define LO_REGNUM 33            /* ... */
#define BADVADDR_REGNUM 35	/* bad vaddr for addressing exception */
#define CAUSE_REGNUM 36		/* describes last exception */
#define PC_REGNUM 37		/* Contains program counter */
#define FP0_REGNUM 38           /* Floating point register 0 (single float) */
#define FCRCS_REGNUM 70         /* FP control/status */
#define FCRIR_REGNUM 71         /* FP implementation/revision */
#define FP_REGNUM 72		/* Pseudo register that contains true address of executing stack frame */
#define	FIRST_EMBED_REGNUM 73	/* First supervisor register for embedded use */
#define	LAST_EMBED_REGNUM 79	/* Last one */

/* Define DO_REGISTERS_INFO() to do machine-specific formatting
   of register dumps. */

#define DO_REGISTERS_INFO(_regnum, fp) mips_do_registers_info(_regnum, fp)

/* Total amount of space needed to store our copies of the machine's
   register state, the array `registers'.  */
#define REGISTER_BYTES (NUM_REGS*4)

/* Index within `registers' of the first byte of the space for
   register N.  */

#define REGISTER_BYTE(N) ((N) * 4)

/* Number of bytes of storage in the actual machine representation
   for register N.  On mips, all regs are 4 bytes.  */

#define REGISTER_RAW_SIZE(N) 4

/* Number of bytes of storage in the program's representation
   for register N.  On mips, all regs are 4 bytes.  */

#define REGISTER_VIRTUAL_SIZE(N) 4

/* Largest value REGISTER_RAW_SIZE can have.  */

#define MAX_REGISTER_RAW_SIZE 8

/* Largest value REGISTER_VIRTUAL_SIZE can have.  */

#define MAX_REGISTER_VIRTUAL_SIZE 8

/* Return the GDB type object for the "standard" data type
   of data in register N.  */

#define REGISTER_VIRTUAL_TYPE(N) \
	(((N) >= FP0_REGNUM && (N) < FP0_REGNUM+32)  \
	 ? builtin_type_float : builtin_type_int) \

#if HOST_BYTE_ORDER == BIG_ENDIAN
/* All mips targets store doubles in a register pair with the least
   significant register in the lower numbered register.
   If the host is big endian, double register values need conversion between
   memory and register formats.  */

#define REGISTER_CONVERT_TO_TYPE(n, type, buffer)			\
  do {if ((n) >= FP0_REGNUM && (n) < FP0_REGNUM + 32 && 		\
	  TYPE_CODE(type) == TYPE_CODE_FLT && TYPE_LENGTH(type) == 8) { \
        char __temp[4];							\
	memcpy (__temp, ((char *)(buffer))+4, 4);			\
	memcpy (((char *)(buffer))+4, (buffer), 4); 			\
	memcpy (((char *)(buffer)), __temp, 4); }} while (0)

#define REGISTER_CONVERT_FROM_TYPE(n, type, buffer)			\
  do {if ((n) >= FP0_REGNUM && (n) < FP0_REGNUM + 32 &&			\
	  TYPE_CODE(type) == TYPE_CODE_FLT && TYPE_LENGTH(type) == 8) { \
        char __temp[4];							\
	memcpy (__temp, ((char *)(buffer))+4, 4);			\
	memcpy (((char *)(buffer))+4, (buffer), 4); 			\
	memcpy (((char *)(buffer)), __temp, 4); }} while (0)
#endif

/* Store the address of the place in which to copy the structure the
   subroutine will return.  Handled by mips_push_arguments.  */

#define STORE_STRUCT_RETURN(addr, sp)	/**/

/* Extract from an array REGBUF containing the (raw) register state
   a function return value of type TYPE, and copy that, in virtual format,
   into VALBUF.  XXX floats */

#define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
  mips_extract_return_value(TYPE, REGBUF, VALBUF)

/* Write into appropriate registers a function return value
   of type TYPE, given in virtual format.  */

#define STORE_RETURN_VALUE(TYPE,VALBUF) \
  mips_store_return_value(TYPE, VALBUF)

/* Extract from an array REGBUF containing the (raw) register state
   the address in which a function should return its structure value,
   as a CORE_ADDR (or an expression that can be used as one).  */
/* The address is passed in a0 upon entry to the function, but when
   the function exits, the compiler has copied the value to v0.  This
   convention is specified by the System V ABI, so I think we can rely
   on it.  */

#define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) \
  (extract_address (REGBUF + REGISTER_BYTE (V0_REGNUM), \
		    REGISTER_RAW_SIZE (V0_REGNUM)))

/* Structures are returned by ref in extra arg0 */
#define USE_STRUCT_CONVENTION(gcc_p, type)	1

\f
/* Describe the pointer in each stack frame to the previous stack frame
   (its caller).  */

/* FRAME_CHAIN takes a frame's nominal address
   and produces the frame's chain-pointer. */

#define FRAME_CHAIN(thisframe) (FRAME_ADDR)mips_frame_chain(thisframe)

/* Define other aspects of the stack frame.  */


/* A macro that tells us whether the function invocation represented
   by FI does not have a frame on the stack associated with it.  If it
   does not, FRAMELESS is set to 1, else 0.  */
/* We handle this differently for mips, and maybe we should not */

#define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS)  {(FRAMELESS) = 0;}

/* Saved Pc.  */

#define FRAME_SAVED_PC(FRAME)	(mips_frame_saved_pc(FRAME))

#define FRAME_ARGS_ADDRESS(fi)	(fi)->frame

#define FRAME_LOCALS_ADDRESS(fi) (fi)->frame

/* Return number of args passed to a frame.
   Can return -1, meaning no way to tell.  */

#define FRAME_NUM_ARGS(num, fi)	(num = mips_frame_num_args(fi))

/* Return number of bytes at start of arglist that are not really args.  */

#define FRAME_ARGS_SKIP 0

/* 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.  */

#define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) ( \
  (frame_saved_regs) = *(frame_info)->saved_regs, \
  (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame)

\f
/* Things needed for making the inferior call functions.  */

/* Stack has strict alignment. However, use PUSH_ARGUMENTS
   to take care of it. */
/*#define STACK_ALIGN(addr)	(((addr)+3)&~3)*/

#define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
    sp = mips_push_arguments(nargs, args, sp, struct_return, struct_addr)

/* Push an empty stack frame, to record the current PC, etc.  */

#define PUSH_DUMMY_FRAME 	mips_push_dummy_frame()

/* Discard from the stack the innermost frame, restoring all registers.  */

#define POP_FRAME		mips_pop_frame()

#define MK_OP(op,rs,rt,offset) (((op)<<26)|((rs)<<21)|((rt)<<16)|(offset))
#define CALL_DUMMY_SIZE (16*4)
#define Dest_Reg 2
#define CALL_DUMMY {\
 MK_OP(0,RA_REGNUM,0,8),	/* jr $ra # Fake ABOUT_TO_RETURN ...*/\
 0,				/* nop 	  #  ... to stop raw backtrace*/\
 0x27bd0000,			/* addu	sp,?0 # Pseudo prologue */\
/* Start here: */\
 MK_OP(061,SP_REGNUM,12,0),	/* lwc1 $f12,0(sp) # Reload FP regs*/\
 MK_OP(061,SP_REGNUM,13,4),	/* lwc1 $f13,4(sp) */\
 MK_OP(061,SP_REGNUM,14,8),	/* lwc1 $f14,8(sp) */\
 MK_OP(061,SP_REGNUM,15,12),	/* lwc1 $f15,12(sp) */\
 MK_OP(043,SP_REGNUM,4,0),	/* lw $r4,0(sp) # Reload first 4 args*/\
 MK_OP(043,SP_REGNUM,5,4),	/* lw $r5,4(sp) */\
 MK_OP(043,SP_REGNUM,6,8),	/* lw $r6,8(sp) */\
 MK_OP(043,SP_REGNUM,7,12),	/* lw $r7,12(sp) */\
 (017<<26)| (Dest_Reg << 16),	/* lui $r31,<target upper 16 bits>*/\
 MK_OP(13,Dest_Reg,Dest_Reg,0),	/* ori $r31,$r31,<lower 16 bits>*/ \
 (Dest_Reg<<21) | (31<<11) | 9,	/* jalr $r31 */\
 MK_OP(043,SP_REGNUM,7,12),	/* lw $r7,12(sp) */\
 0x5000d,			/* bpt */\
}

#define CALL_DUMMY_START_OFFSET 12

/* Insert the specified number of args and function address
   into a call sequence of the above form stored at DUMMYNAME.  */

#if TARGET_BYTE_ORDER == BIG_ENDIAN
/* For big endian mips machines the loading of FP values depends on whether
   they are single or double precision. */
#define FIX_CALL_DUMMY(dummyname, start_sp, fun, nargs, args, rettype, gcc_p) \
  do {									\
    ((int*)(dummyname))[11] |= ((unsigned long)(fun)) >> 16;		\
    ((int*)(dummyname))[12] |= (unsigned short)(fun);			\
    if (! mips_fpu) {							\
      ((int *) (dummyname))[3] = 0; ((int *) (dummyname))[4] = 0;	\
      ((int *) (dummyname))[5] = 0; ((int *) (dummyname))[6] = 0;	\
    } else {								\
      if (nargs > 0 &&							\
	  TYPE_CODE(VALUE_TYPE(args[0])) == TYPE_CODE_FLT &&		\
	  TYPE_LENGTH(VALUE_TYPE(args[0])) == 8) {			\
	((int *) (dummyname))[3] = MK_OP(061,SP_REGNUM,12,4);		\
	((int *) (dummyname))[4] = MK_OP(061,SP_REGNUM,13,0);		\
      }									\
      if (nargs > 1 &&							\
	  TYPE_CODE(VALUE_TYPE(args[1])) == TYPE_CODE_FLT &&		\
	  TYPE_LENGTH(VALUE_TYPE(args[1])) == 8) {			\
	((int *) (dummyname))[5] = MK_OP(061,SP_REGNUM,14,12);		\
	((int *) (dummyname))[6] = MK_OP(061,SP_REGNUM,15,8);		\
      }									\
    }									\
  } while (0)
#else
#define FIX_CALL_DUMMY(dummyname, start_sp, fun, nargs,	args, rettype, gcc_p)\
  do \
    { \
      ((int*)(dummyname))[11] |= ((unsigned long)(fun)) >> 16; \
      ((int*)(dummyname))[12] |= (unsigned short)(fun); \
      if (! mips_fpu) \
	{ \
	  ((int *) (dummyname))[3] = 0; \
	  ((int *) (dummyname))[4] = 0; \
	  ((int *) (dummyname))[5] = 0; \
	  ((int *) (dummyname))[6] = 0; \
	} \
    } \
  while (0)
#endif

/* There's a mess in stack frame creation.  See comments in blockframe.c
   near reference to INIT_FRAME_PC_FIRST.  */

#define	INIT_FRAME_PC(fromleaf, prev) /* nada */

#define INIT_FRAME_PC_FIRST(fromleaf, prev) \
  (prev)->pc = ((fromleaf) ? SAVED_PC_AFTER_CALL ((prev)->next) : \
	      (prev)->next ? FRAME_SAVED_PC ((prev)->next) : read_pc ());

/* Special symbol found in blocks associated with routines.  We can hang
   mips_extra_func_info_t's off of this.  */

#define MIPS_EFI_SYMBOL_NAME "__GDB_EFI_INFO__"

/* Specific information about a procedure.
   This overlays the MIPS's PDR records, 
   mipsread.c (ab)uses this to save memory */

typedef struct mips_extra_func_info {
	long	numargs;	/* number of args to procedure (was iopt) */
	PDR	pdr;		/* Procedure descriptor record */
} *mips_extra_func_info_t;

#define EXTRA_FRAME_INFO \
  mips_extra_func_info_t proc_desc; \
  int num_args;\
  struct frame_saved_regs *saved_regs;

#define INIT_EXTRA_FRAME_INFO(fromleaf, fci) init_extra_frame_info(fci)

#define	PRINT_EXTRA_FRAME_INFO(fi) \
  { \
    if (fi && fi->proc_desc && fi->proc_desc->pdr.framereg < NUM_REGS) \
      printf_filtered (" frame pointer is at %s+%d\n", \
                       reg_names[fi->proc_desc->pdr.framereg], \
                                 fi->proc_desc->pdr.frameoffset); \
  }

/* It takes two values to specify a frame on the MIPS.  Sigh.

   In fact, at the moment, the *PC* is the primary value that sets up
   a frame.  The PC is looked up to see what function it's in; symbol
   information from that function tells us which register is the frame
   pointer base, and what offset from there is the "virtual frame pointer".
   (This is usually an offset from SP.)  FIXME -- this should be cleaned
   up so that the primary value is the SP, and the PC is used to disambiguate
   multiple functions with the same SP that are at different stack levels. */

#define SETUP_ARBITRARY_FRAME(argc, argv) setup_arbitrary_frame (argc, argv)
/* FIXME:  Depends on equivalence between FRAME and "struct frame_info *",
   and equivalence between CORE_ADDR and FRAME_ADDR. */
extern struct frame_info *setup_arbitrary_frame PARAMS ((int, CORE_ADDR *));

/* Convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */

#define STAB_REG_TO_REGNUM(num) ((num) < 32 ? (num) : (num)+FP0_REGNUM-38)

/* Convert a ecoff register number to a gdb REGNUM */

#define ECOFF_REG_TO_REGNUM(num) ((num) < 32 ? (num) : (num)+FP0_REGNUM-32)