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author | lost |
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date | Sat, 17 Jan 2009 16:55:53 +0000 |
parents | 1f598d89b9b0 |
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/* lwval.c 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 implementations associated with the expression evaluator used by LWASM. */ #include <malloc.h> #define __lwval_c_seen__ #include "lwval.h" LWVAL *lwval_construct_int(int value) { LWVAL *v; v = malloc(sizeof(LWVAL)); if (!v) return NULL; v -> lwval_type = LWVAL_TYPE_INT; v -> dt.lwval_int = value; return v; } LWVAL *lwval_construct_err(int errno) { LWVAL *v; v = malloc(sizeof(LWVAL)); if (!v) return NULL; v -> lwval_type = LWVAL_TYPE_ERR; v -> dt.lwval_int = errno; return v; } LWVAL *lwval_construct_nan(void) { LWVAL *v; v = malloc(sizeof(LWVAL)); if (!v) return NULL; v -> lwval_type = LWVAL_TYPE_NAN; return v; } LWVAL *lwval_construct_undef(void) { LWVAL *v; v = malloc(sizeof(LWVAL)); if (!v) return NULL; v -> lwval_type = LWVAL_TYPE_UNDEF; return v; } LWVAL *lwval_construct_expr(LWVAL *v1, LWVAL *v2, int op) { LWVAL *v; v = malloc(sizeof(LWVAL)); if (!v) return NULL; v -> lwval_type = LWVAL_TYPE_EXPR; v -> dt.expr.v1 = v1; v -> dt.expr.v2 = v2; v -> dt.expr.op = op; return v; } void lwval_destroy(LWVAL *value) { if (value) { lwval_clear(value); free(value); } } // performs a deep copy of an LWVAL, including ALL referenced values void lwval_dup(LWVAL *v1, LWVAL *v2) { lwval_clear(v2); switch (v1 -> lwval_type) { case LWVAL_TYPE_INT: case LWVAL_TYPE_ERR: v2 -> dt.lwval_int = v1 -> dt.lwval_int; break; case LWVAL_TYPE_EXPR: v2 -> dt.expr.op = v1 -> dt.expr.op; if (v1 -> dt.expr.v1) { v2 -> dt.expr.v1 = lwval_construct_undef(); lwval_dup(v1 -> dt.expr.v1, v2 -> dt.expr.v1); } else v2 -> dt.expr.v1 = NULL; if (v1 -> dt.expr.v2) { v2 -> dt.expr.v2 = lwval_construct_undef(); lwval_dup(v1 -> dt.expr.v2, v2 -> dt.expr.v2); } else v2 -> dt.expr.v2 = NULL; break; } v2 -> lwval_type = v1 -> lwval_type; } void lwval_clear(LWVAL *value) { switch (value -> lwval_type) { case LWVAL_TYPE_EXPR: lwval_destroy(value -> dt.expr.v1); lwval_destroy(value -> dt.expr.v2); break; } value -> lwval_type = LWVAL_TYPE_UNDEF; } // for integer, simply negate value // for expr, change to "-1 * (expr)" // everything else: error LWVAL *lwval_neg(LWVAL *v1) { switch (v1 -> lwval_type) { case LWVAL_TYPE_INT: v1 -> dt.lwval_int = -(v1 -> dt.lwval_int); break; case LWVAL_TYPE_EXPR: { LWVAL *v, *v2; v = lwval_construct_undef(); lwval_dup(v1, v); lwval_clear(v1); v2 = lwval_construct_expr(lwval_construct_int(-1), v, '*'); lwval_dup(v2, v1); lwval_destroy(v2); } break; default: lwval_clear(v1); v1 -> lwval_type = LWVAL_TYPE_ERR; v1 -> dt.lwval_int = 1; } return v1; } // v1 + v2 -> v1 LWVAL *lwval_add(LWVAL *v1, LWVAL *v2) { } // v1 - v2 -> v1 LWVAL *lwval_sub(LWVAL *v1, LWVAL *v2) { } // v1 * v2 -> v1 LWVAL *lwval_mul(LWVAL *v1, LWVAL *v2) { } // v1 / v2 -> v1 LWVAL *lwval_div(LWVAL *v1, LWVAL *v2) { } // v1 % v2 -> v1 LWVAL *lwval_mod(LWVAL *v1, LWVAL *v2) { }