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view src/expr.h @ 257:e27279180a73 2.x
Added support for include path to LWASM
author | lost |
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date | Tue, 22 Dec 2009 04:53:20 +0000 |
parents | 718998b673ee |
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/* expr.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/>. */ /* Definitions for expression evaluator */ #ifndef __expr_h_seen__ #define __expr_h_seen__ #ifndef __expr_c_seen__ #define __expr_E__ extern #else #define __expr_E__ #endif // term types #define LWASM_TERM_NONE 0 #define LWASM_TERM_OPER 1 // an operator #define LWASM_TERM_INT 2 // 32 bit signed integer #define LWASM_TERM_SYM 3 // symbol reference #define LWASM_TERM_SECBASE 4 // section base reference // operator types #define LWASM_OPER_NONE 0 #define LWASM_OPER_PLUS 1 // + #define LWASM_OPER_MINUS 2 // - #define LWASM_OPER_TIMES 3 // * #define LWASM_OPER_DIVIDE 4 // / #define LWASM_OPER_MOD 5 // % #define LWASM_OPER_INTDIV 6 // \ (don't end line with \) #define LWASM_OPER_BWAND 7 // bitwise AND #define LWASM_OPER_BWOR 8 // bitwise OR #define LWASM_OPER_BWXOR 9 // bitwise XOR #define LWASM_OPER_AND 10 // boolean AND #define LWASM_OPER_OR 11 // boolean OR #define LWASM_OPER_NEG 12 // - unary negation (2's complement) #define LWASM_OPER_COM 13 // ^ unary 1's complement // term structure typedef struct lwasm_expr_term_s { int term_type; // type of term (see above) char *symbol; // name of a symbol int value; // value of the term (int) or operator number (OPER) } lwasm_expr_term_t; // type for an expression evaluation stack typedef struct lwasm_expr_stack_node_s lwasm_expr_stack_node_t; struct lwasm_expr_stack_node_s { lwasm_expr_term_t *term; lwasm_expr_stack_node_t *prev; lwasm_expr_stack_node_t *next; }; typedef struct lwasm_expr_stack_s { lwasm_expr_stack_node_t *head; lwasm_expr_stack_node_t *tail; } lwasm_expr_stack_t; __expr_E__ void lwasm_expr_term_free(lwasm_expr_term_t *t); __expr_E__ lwasm_expr_term_t *lwasm_expr_term_create_oper(int oper); __expr_E__ lwasm_expr_term_t *lwasm_expr_term_create_sym(char *sym); __expr_E__ lwasm_expr_term_t *lwasm_expr_term_create_int(int val); __expr_E__ lwasm_expr_term_t *lwasm_expr_term_create_secbase(void); __expr_E__ lwasm_expr_term_t *lwasm_expr_term_dup(lwasm_expr_term_t *t); __expr_E__ void lwasm_expr_stack_free(lwasm_expr_stack_t *s); __expr_E__ lwasm_expr_stack_t *lwasm_expr_stack_create(void); __expr_E__ void lwasm_expr_stack_push(lwasm_expr_stack_t *s, lwasm_expr_term_t *t); __expr_E__ lwasm_expr_term_t *lwasm_expr_stack_pop(lwasm_expr_stack_t *s); /* Evaluate an expression. The result is an lwasm_expr_stack_t pointer. If the expression evaluates to a constant result, the stack will contain exactly one value which will be a constant. Otherwise, the stack will contain the expression with all operations that can be evaluated completely evaluated. You must call lwasm_expr_stack_free() on the result when you are finished with it. */ __expr_E__ lwasm_expr_stack_t *lwasm_expr_eval(const char *inp, const char **outp, lwasm_expr_stack_t *(*sfunc)(char *sym, void *state), void *state); // simplify expression __expr_E__ int lwasm_expr_reval(lwasm_expr_stack_t *s, lwasm_expr_stack_t *(*sfunc)(char *sym, void *state), void *state); // useful macros // is the expression "simple" (one term)? #define lwasm_expr_is_simple(s) ((s) -> head == (s) -> tail) // is the expression constant? #define lwasm_expr_is_constant(s) (lwasm_expr_is_simple(s) && (!((s) -> head) || (s) -> head -> term -> term_type == LWASM_TERM_INT)) // get the constant value of an expression or 0 if not constant #define lwasm_expr_get_value(s) (lwasm_expr_is_constant(s) ? ((s) -> head ? (s) -> head -> term -> value : 0) : 0) #undef __expr_E__ #endif // __expr_h_seen__