/*

  Copyright (C) 2000,2004 Silicon Graphics, Inc.  All Rights Reserved.

  This program is free software; you can redistribute it and/or modify it
  under the terms of version 2.1 of the GNU Lesser General Public License 
  as published by the Free Software Foundation.

  This program is distributed in the hope that it would be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

  Further, this software is distributed without any warranty that it is
  free of the rightful claim of any third person regarding infringement 
  or the like.  Any license provided herein, whether implied or 
  otherwise, applies only to this software file.  Patent licenses, if
  any, provided herein do not apply to combinations of this program with 
  other software, or any other product whatsoever.  

  You should have received a copy of the GNU Lesser General Public 
  License along with this program; if not, write the Free Software 
  Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, 
  USA.

  Contact information:  Silicon Graphics, Inc., 1500 Crittenden Lane,
  Mountain View, CA 94043, or:

  http://www.sgi.com

  For further information regarding this notice, see:

  http://oss.sgi.com/projects/GenInfo/NoticeExplan

*/



#include "config.h"
#include "libdwarfdefs.h"
#include <stdio.h>
#include <string.h>
#include "pro_incl.h"
#include "pro_expr.h"

/*
    This function creates a new expression 
    struct that can be used to build up a
    location expression.
*/
Dwarf_P_Expr
dwarf_new_expr(Dwarf_P_Debug dbg, Dwarf_Error * error)
{
    Dwarf_P_Expr ret_expr;

    if (dbg == NULL) {
	_dwarf_p_error(NULL, error, DW_DLE_DBG_NULL);
	return (NULL);
    }

    ret_expr = (Dwarf_P_Expr)
	_dwarf_p_get_alloc(dbg, sizeof(struct Dwarf_P_Expr_s));
    if (ret_expr == NULL) {
	_dwarf_p_error(dbg, error, DW_DLE_ALLOC_FAIL);
	return (NULL);
    }

    ret_expr->ex_dbg = dbg;

    return (ret_expr);
}


Dwarf_Unsigned
dwarf_add_expr_gen(Dwarf_P_Expr expr,
		   Dwarf_Small opcode,
		   Dwarf_Unsigned val1,
		   Dwarf_Unsigned val2, Dwarf_Error * error)
{
    char encode_buffer[2 * ENCODE_SPACE_NEEDED];	/* 2* since
							   used to
							   concatenate
							   2 leb's
							   below */
    char encode_buffer2[ENCODE_SPACE_NEEDED];
    int res;
    Dwarf_P_Debug dbg = expr->ex_dbg;

    /* 
       Give the buffer where the operands are first going to be
       assembled the largest alignment. */
    Dwarf_Unsigned operand_buffer[10];

    /* 
       Size of the byte stream buffer that needs to be memcpy-ed. */
    int operand_size;

    /* 
       Points to the byte stream for the first operand, and finally to
       the buffer that is memcp-ed into the Dwarf_P_Expr_s struct. */
    Dwarf_Small *operand;

    /* Size of the byte stream for second operand. */
    int operand2_size;

    /* Points to next byte to be written in Dwarf_P_Expr_s struct. */
    Dwarf_Small *next_byte_ptr;

    /* Offset past the last byte written into Dwarf_P_Expr_s. */
    int next_byte_offset;

    /* ***** BEGIN CODE ***** */

    if (expr == NULL) {
	_dwarf_p_error(NULL, error, DW_DLE_EXPR_NULL);
	return (DW_DLV_NOCOUNT);
    }

    if (expr->ex_dbg == NULL) {
	_dwarf_p_error(NULL, error, DW_DLE_DBG_NULL);
	return (DW_DLV_NOCOUNT);
    }

    operand = NULL;
    operand_size = 0;

    switch (opcode) {
    case DW_OP_reg0:
    case DW_OP_reg1:
    case DW_OP_reg2:
    case DW_OP_reg3:
    case DW_OP_reg4:
    case DW_OP_reg5:
    case DW_OP_reg6:
    case DW_OP_reg7:
    case DW_OP_reg8:
    case DW_OP_reg9:
    case DW_OP_reg10:
    case DW_OP_reg11:
    case DW_OP_reg12:
    case DW_OP_reg13:
    case DW_OP_reg14:
    case DW_OP_reg15:
    case DW_OP_reg16:
    case DW_OP_reg17:
    case DW_OP_reg18:
    case DW_OP_reg19:
    case DW_OP_reg20:
    case DW_OP_reg21:
    case DW_OP_reg22:
    case DW_OP_reg23:
    case DW_OP_reg24:
    case DW_OP_reg25:
    case DW_OP_reg26:
    case DW_OP_reg27:
    case DW_OP_reg28:
    case DW_OP_reg29:
    case DW_OP_reg30:
    case DW_OP_reg31:
	break;

    case DW_OP_breg0:
    case DW_OP_breg1:
    case DW_OP_breg2:
    case DW_OP_breg3:
    case DW_OP_breg4:
    case DW_OP_breg5:
    case DW_OP_breg6:
    case DW_OP_breg7:
    case DW_OP_breg8:
    case DW_OP_breg9:
    case DW_OP_breg10:
    case DW_OP_breg11:
    case DW_OP_breg12:
    case DW_OP_breg13:
    case DW_OP_breg14:
    case DW_OP_breg15:
    case DW_OP_breg16:
    case DW_OP_breg17:
    case DW_OP_breg18:
    case DW_OP_breg19:
    case DW_OP_breg20:
    case DW_OP_breg21:
    case DW_OP_breg22:
    case DW_OP_breg23:
    case DW_OP_breg24:
    case DW_OP_breg25:
    case DW_OP_breg26:
    case DW_OP_breg27:
    case DW_OP_breg28:
    case DW_OP_breg29:
    case DW_OP_breg30:
    case DW_OP_breg31:
	res = _dwarf_pro_encode_signed_leb128_nm(val1,
						 &operand_size,
						 encode_buffer,
						 sizeof(encode_buffer));
	if (res != DW_DLV_OK) {
	    _dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	    return (DW_DLV_NOCOUNT);
	}
	operand = (Dwarf_Small *) encode_buffer;
	break;

    case DW_OP_regx:
	res = _dwarf_pro_encode_leb128_nm(val1, &operand_size,
					  encode_buffer,
					  sizeof(encode_buffer));
	if (res != DW_DLV_OK) {
	    _dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	    return (DW_DLV_NOCOUNT);
	}
	operand = (Dwarf_Small *) encode_buffer;
	break;

    case DW_OP_lit0:
    case DW_OP_lit1:
    case DW_OP_lit2:
    case DW_OP_lit3:
    case DW_OP_lit4:
    case DW_OP_lit5:
    case DW_OP_lit6:
    case DW_OP_lit7:
    case DW_OP_lit8:
    case DW_OP_lit9:
    case DW_OP_lit10:
    case DW_OP_lit11:
    case DW_OP_lit12:
    case DW_OP_lit13:
    case DW_OP_lit14:
    case DW_OP_lit15:
    case DW_OP_lit16:
    case DW_OP_lit17:
    case DW_OP_lit18:
    case DW_OP_lit19:
    case DW_OP_lit20:
    case DW_OP_lit21:
    case DW_OP_lit22:
    case DW_OP_lit23:
    case DW_OP_lit24:
    case DW_OP_lit25:
    case DW_OP_lit26:
    case DW_OP_lit27:
    case DW_OP_lit28:
    case DW_OP_lit29:
    case DW_OP_lit30:
    case DW_OP_lit31:
	break;

    case DW_OP_addr:
	_dwarf_p_error(expr->ex_dbg, error, DW_DLE_BAD_EXPR_OPCODE);
	return (DW_DLV_NOCOUNT);

    case DW_OP_const1u:
    case DW_OP_const1s:
	operand = (Dwarf_Small *) & operand_buffer[0];
	WRITE_UNALIGNED(dbg, operand, &val1, sizeof(val1), 1);
	operand_size = 1;
	break;

    case DW_OP_const2u:
    case DW_OP_const2s:
	operand = (Dwarf_Small *) & operand_buffer[0];
	WRITE_UNALIGNED(dbg, operand, &val1, sizeof(val1), 2);
	operand_size = 2;
	break;

    case DW_OP_const4u:
    case DW_OP_const4s:
	operand = (Dwarf_Small *) & operand_buffer[0];
	WRITE_UNALIGNED(dbg, operand, &val1, sizeof(val1), 4);
	operand_size = 4;
	break;

    case DW_OP_const8u:
    case DW_OP_const8s:
	operand = (Dwarf_Small *) & operand_buffer[0];
	WRITE_UNALIGNED(dbg, operand, &val1, sizeof(val1), 8);
	operand_size = 8;
	break;

    case DW_OP_constu:
	res = _dwarf_pro_encode_leb128_nm(val1,
					  &operand_size,
					  encode_buffer,
					  sizeof(encode_buffer));
	if (res != DW_DLV_OK) {
	    _dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	    return (DW_DLV_NOCOUNT);
	}
	operand = (Dwarf_Small *) encode_buffer;
	break;

    case DW_OP_consts:
	res = _dwarf_pro_encode_signed_leb128_nm(val1,
						 &operand_size,
						 encode_buffer,
						 sizeof(encode_buffer));
	if (res != DW_DLV_OK) {
	    _dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	    return (DW_DLV_NOCOUNT);
	}
	operand = (Dwarf_Small *) encode_buffer;
	break;

    case DW_OP_fbreg:
	res = _dwarf_pro_encode_signed_leb128_nm(val1,
						 &operand_size,
						 encode_buffer,
						 sizeof(encode_buffer));
	if (res != DW_DLV_OK) {
	    _dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	    return (DW_DLV_NOCOUNT);
	}
	operand = (Dwarf_Small *) encode_buffer;
	break;

    case DW_OP_bregx:
	res = _dwarf_pro_encode_leb128_nm(val1, &operand_size,
					  encode_buffer,
					  sizeof(encode_buffer));
	if (res != DW_DLV_OK) {
	    _dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	    return (DW_DLV_NOCOUNT);
	}
	operand = (Dwarf_Small *) encode_buffer;
	/* put this one directly into 'operand' at tail of prev value */
	res = _dwarf_pro_encode_signed_leb128_nm(val2, &operand2_size,
						 ((char *) operand) +
						 operand_size,
						 sizeof
						 (encode_buffer2));
	if (res != DW_DLV_OK) {
	    _dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	    return (DW_DLV_NOCOUNT);
	}
	operand_size += operand2_size;

    case DW_OP_dup:
    case DW_OP_drop:
	break;

    case DW_OP_pick:
	operand = (Dwarf_Small *) & operand_buffer[0];
	/* Cast of val1 to pointer is ok as if val1 does not point into 
	   our (process) address space we are in big trouble anyway
	   (internal error in libdwarf or in libdwarf caller). Compiler 
	   may warn about cast to pointer. */
	WRITE_UNALIGNED(dbg, operand, (const void *) val1,
			sizeof(val1), 1);
	operand_size = 1;
	break;

    case DW_OP_over:
    case DW_OP_swap:
    case DW_OP_rot:
    case DW_OP_deref:
    case DW_OP_xderef:
	break;

    case DW_OP_deref_size:
    case DW_OP_xderef_size:
	operand = (Dwarf_Small *) & operand_buffer[0];
	/* Cast of val1 to pointer is ok as if val1 does not point into 
	   our (process) address space we are in big trouble anyway
	   (internal error in libdwarf or in libdwarf caller). Compiler 
	   may warn about cast to pointer. */
	WRITE_UNALIGNED(dbg, operand, (const void *) val1,
			sizeof(val1), 1);
	operand_size = 1;
	break;

    case DW_OP_abs:
    case DW_OP_and:
    case DW_OP_div:
    case DW_OP_minus:
    case DW_OP_mod:
    case DW_OP_mul:
    case DW_OP_neg:
    case DW_OP_not:
    case DW_OP_or:
    case DW_OP_plus:
	break;

    case DW_OP_plus_uconst:
	res = _dwarf_pro_encode_leb128_nm(val1, &operand_size,
					  encode_buffer,
					  sizeof(encode_buffer));
	if (res != DW_DLV_OK) {
	    _dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	    return (DW_DLV_NOCOUNT);
	}
	operand = (Dwarf_Small *) encode_buffer;
	break;

    case DW_OP_shl:
    case DW_OP_shr:
    case DW_OP_shra:
    case DW_OP_xor:
	break;

    case DW_OP_le:
    case DW_OP_ge:
    case DW_OP_eq:
    case DW_OP_lt:
    case DW_OP_gt:
    case DW_OP_ne:
	break;

    case DW_OP_skip:
    case DW_OP_bra:
	/* FIX: unhandled! OP_bra, OP_skip! */
	_dwarf_p_error(expr->ex_dbg, error, DW_DLE_BAD_EXPR_OPCODE);
	return (DW_DLV_NOCOUNT);

    case DW_OP_piece:
	res = _dwarf_pro_encode_leb128_nm(val1, &operand_size,
					  encode_buffer,
					  sizeof(encode_buffer));
	if (res != DW_DLV_OK) {
	    _dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	    return (DW_DLV_NOCOUNT);
	}
	operand = (Dwarf_Small *) encode_buffer;
	break;

    case DW_OP_nop:
	break;

    default:
	_dwarf_p_error(expr->ex_dbg, error, DW_DLE_BAD_EXPR_OPCODE);
	return (DW_DLV_NOCOUNT);
    }

    next_byte_offset = expr->ex_next_byte_offset + operand_size + 1;

    if (next_byte_offset > MAXIMUM_LOC_EXPR_LENGTH) {
	_dwarf_p_error(expr->ex_dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	return (DW_DLV_NOCOUNT);
    }

    next_byte_ptr =
	&(expr->ex_byte_stream[0]) + expr->ex_next_byte_offset;

    *next_byte_ptr = opcode;
    next_byte_ptr++;
    memcpy(next_byte_ptr, operand, operand_size);

    expr->ex_next_byte_offset = next_byte_offset;
    return (next_byte_offset);
}

Dwarf_Unsigned
dwarf_add_expr_addr_b(Dwarf_P_Expr expr,
		      Dwarf_Unsigned addr,
		      Dwarf_Unsigned sym_index, Dwarf_Error * error)
{
    Dwarf_P_Debug dbg;
    Dwarf_Small *next_byte_ptr;
    Dwarf_Unsigned next_byte_offset;
    int upointer_size;

    if (expr == NULL) {
	_dwarf_p_error(NULL, error, DW_DLE_EXPR_NULL);
	return (DW_DLV_NOCOUNT);
    }

    dbg = expr->ex_dbg;
    if (dbg == NULL) {
	_dwarf_p_error(NULL, error, DW_DLE_DBG_NULL);
	return (DW_DLV_NOCOUNT);
    }

    upointer_size = dbg->de_pointer_size;
    next_byte_offset = expr->ex_next_byte_offset + upointer_size + 1;
    if (next_byte_offset > MAXIMUM_LOC_EXPR_LENGTH) {
	_dwarf_p_error(dbg, error, DW_DLE_EXPR_LENGTH_BAD);
	return (DW_DLV_NOCOUNT);
    }

    next_byte_ptr =
	&(expr->ex_byte_stream[0]) + expr->ex_next_byte_offset;

    *next_byte_ptr = DW_OP_addr;
    next_byte_ptr++;
    WRITE_UNALIGNED(dbg, next_byte_ptr, (const void *) &addr,
		    sizeof(addr), upointer_size);

    if (expr->ex_reloc_offset != 0) {
	_dwarf_p_error(dbg, error, DW_DLE_MULTIPLE_RELOC_IN_EXPR);
	return (DW_DLV_NOCOUNT);
    }

    expr->ex_reloc_sym_index = sym_index;
    expr->ex_reloc_offset = expr->ex_next_byte_offset + 1;

    expr->ex_next_byte_offset = next_byte_offset;
    return (next_byte_offset);
}

Dwarf_Unsigned
dwarf_add_expr_addr(Dwarf_P_Expr expr,
		    Dwarf_Unsigned addr,
		    Dwarf_Signed sym_index, Dwarf_Error * error)
{
    return
	dwarf_add_expr_addr_b(expr, addr, (Dwarf_Unsigned) sym_index,
			      error);
}


Dwarf_Unsigned
dwarf_expr_current_offset(Dwarf_P_Expr expr, Dwarf_Error * error)
{
    if (expr == NULL) {
	_dwarf_p_error(NULL, error, DW_DLE_EXPR_NULL);
	return (DW_DLV_NOCOUNT);
    }

    if (expr->ex_dbg == NULL) {
	_dwarf_p_error(NULL, error, DW_DLE_DBG_NULL);
	return (DW_DLV_NOCOUNT);
    }

    return (expr->ex_next_byte_offset);
}


Dwarf_Addr
dwarf_expr_into_block(Dwarf_P_Expr expr,
		      Dwarf_Unsigned * length, Dwarf_Error * error)
{
    if (expr == NULL) {
	_dwarf_p_error(NULL, error, DW_DLE_EXPR_NULL);
	return (DW_DLV_BADADDR);
    }

    if (expr->ex_dbg == NULL) {
	_dwarf_p_error(NULL, error, DW_DLE_DBG_NULL);
	return (DW_DLV_BADADDR);
    }

    if (length != NULL)
	*length = expr->ex_next_byte_offset;
    /* The following cast from pointer to integer is ok as long as
       Dwarf_Addr is at least as large as a pointer. Which is a
       requirement of libdwarf so must be satisfied (some compilers
       emit a warning about the following line). */
    return ((Dwarf_Addr) & (expr->ex_byte_stream[0]));
}
