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view src/lwval.h @ 22:b704f7ffc8ba
Added reading of input file for pass1
author | lost |
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date | Fri, 02 Jan 2009 00:43:19 +0000 |
parents | 4f14eae64d38 |
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/* lwval.h Copyright © 2008 William Astle This file is part of LWASM. LWASM 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 3 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, see <http://www.gnu.org/licenses/>. */ /* This file contains definitions associated with the expression evaluator used by LWASM. The core of the entire expression handler is the opaque type LWVAL, pointers to which are passed around to keep track of values. A value may be a simple integer or it could be a more complex expression linked by operators or it could be a polynomial expression. Simple integers are merely a degenerate case of polynomials. The package understands the following operations: addition subtraction multiplication division modulus parentheses unary negation unary "positive" bitwise and bitwise or bitwise not (1's complement) bitwise exclusive or Infix operators can be expressed as LWVAL <op> LWVAL. Thus, the order of operations is only relevant when initially parsing the expression. The order of evaluation is determined by what appears on either side of the <op> as an LWVAL may be an expression. */ #ifndef __lwval_h_seen__ #define __lwval_h_seen__ typedef struct lwval LWVAL; struct lwval_dt_expr { LWVAL *v1; // first value LWVAL *v2; // second value int op; // operator }; union lwval_dt { int lwval_int; // integer type data char *lwval_var; // pointer to variable name struct lwval_dt_expr expr; // expression }; enum { LWVAL_TYPE_UNDEF, // undefined LWVAL_TYPE_NAN, // not a number LWVAL_TYPE_INT, // integer LWVAL_TYPE_VAR, // variable (symbol) LWVAL_TYPE_EXPR, // expression LWVAL_TYPE_ERR // error }; struct lwval { int lwval_type; // data type union lwval_dt dt; // type specific stuff }; #ifndef __lwval_c_seen__ #define __lwval_extern__ extern #else #define __lwval_extern__ #endif __lwval_extern__ LWVAL *lwval_construct_int(int value); __lwval_extern__ LWVAL *lwval_construct_err(int errno); __lwval_extern__ LWVAL *lwval_construct_nan(void); __lwval_extern__ LWVAL *lwval_construct_expr(LWVAL *v1, LWVAL *v2, int op); __lwval_extern__ LWVAL *lwval_construct_undef(void); __lwval_extern__ void lwval_clear(LWVAL *value); __lwval_extern__ void lwval_destroy(LWVAL *value); __lwval_extern__ void lwval_dup(LWVAL *v1, LWVAL *v2); // operators - operate on v1 and v2 in order, result goes into // v1; return v1 __lwval_extern__ LWVAL *lwval_add(LWVAL *v1, LWVAL *v2); __lwval_extern__ LWVAL *lwval_sub(LWVAL *v1, LWVAL *v2); __lwval_extern__ LWVAL *lwval_mul(LWVAL *v1, LWVAL *v2); __lwval_extern__ LWVAL *lwval_div(LWVAL *v1, LWVAL *v2); __lwval_extern__ LWVAL *lwval_mod(LWVAL *v1, LWVAL *v2); __lwval_extern__ LWVAL *lwval_neg(LWVAL *v1); #undef __lwval_extern__ #endif //__lwval_h_seen__