Current Path : /sys/ddb/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/ddb/db_expr.c |
/*- * Mach Operating System * Copyright (c) 1991,1990 Carnegie Mellon University * All Rights Reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * Author: David B. Golub, Carnegie Mellon University * Date: 7/90 */ #include <sys/cdefs.h> __FBSDID("$FreeBSD: release/9.1.0/sys/ddb/db_expr.c 195699 2009-07-14 22:48:30Z rwatson $"); #include <sys/param.h> #include <ddb/ddb.h> #include <ddb/db_lex.h> #include <ddb/db_access.h> #include <ddb/db_command.h> static boolean_t db_add_expr(db_expr_t *valuep); static boolean_t db_mult_expr(db_expr_t *valuep); static boolean_t db_shift_expr(db_expr_t *valuep); static boolean_t db_term(db_expr_t *valuep); static boolean_t db_unary(db_expr_t *valuep); static boolean_t db_term(db_expr_t *valuep) { int t; t = db_read_token(); if (t == tIDENT) { if (!db_value_of_name(db_tok_string, valuep) && !db_value_of_name_pcpu(db_tok_string, valuep) && !db_value_of_name_vnet(db_tok_string, valuep)) { db_error("Symbol not found\n"); /*NOTREACHED*/ } return (TRUE); } if (t == tNUMBER) { *valuep = (db_expr_t)db_tok_number; return (TRUE); } if (t == tDOT) { *valuep = (db_expr_t)db_dot; return (TRUE); } if (t == tDOTDOT) { *valuep = (db_expr_t)db_prev; return (TRUE); } if (t == tPLUS) { *valuep = (db_expr_t) db_next; return (TRUE); } if (t == tDITTO) { *valuep = (db_expr_t)db_last_addr; return (TRUE); } if (t == tDOLLAR) { if (!db_get_variable(valuep)) return (FALSE); return (TRUE); } if (t == tLPAREN) { if (!db_expression(valuep)) { db_error("Syntax error\n"); /*NOTREACHED*/ } t = db_read_token(); if (t != tRPAREN) { db_error("Syntax error\n"); /*NOTREACHED*/ } return (TRUE); } db_unread_token(t); return (FALSE); } static boolean_t db_unary(db_expr_t *valuep) { int t; t = db_read_token(); if (t == tMINUS) { if (!db_unary(valuep)) { db_error("Syntax error\n"); /*NOTREACHED*/ } *valuep = -*valuep; return (TRUE); } if (t == tSTAR) { /* indirection */ if (!db_unary(valuep)) { db_error("Syntax error\n"); /*NOTREACHED*/ } *valuep = db_get_value((db_addr_t)*valuep, sizeof(void *), FALSE); return (TRUE); } db_unread_token(t); return (db_term(valuep)); } static boolean_t db_mult_expr(db_expr_t *valuep) { db_expr_t lhs, rhs; int t; if (!db_unary(&lhs)) return (FALSE); t = db_read_token(); while (t == tSTAR || t == tSLASH || t == tPCT || t == tHASH) { if (!db_term(&rhs)) { db_error("Syntax error\n"); /*NOTREACHED*/ } if (t == tSTAR) lhs *= rhs; else { if (rhs == 0) { db_error("Divide by 0\n"); /*NOTREACHED*/ } if (t == tSLASH) lhs /= rhs; else if (t == tPCT) lhs %= rhs; else lhs = ((lhs+rhs-1)/rhs)*rhs; } t = db_read_token(); } db_unread_token(t); *valuep = lhs; return (TRUE); } static boolean_t db_add_expr(db_expr_t *valuep) { db_expr_t lhs, rhs; int t; if (!db_mult_expr(&lhs)) return (FALSE); t = db_read_token(); while (t == tPLUS || t == tMINUS) { if (!db_mult_expr(&rhs)) { db_error("Syntax error\n"); /*NOTREACHED*/ } if (t == tPLUS) lhs += rhs; else lhs -= rhs; t = db_read_token(); } db_unread_token(t); *valuep = lhs; return (TRUE); } static boolean_t db_shift_expr(db_expr_t *valuep) { db_expr_t lhs, rhs; int t; if (!db_add_expr(&lhs)) return (FALSE); t = db_read_token(); while (t == tSHIFT_L || t == tSHIFT_R) { if (!db_add_expr(&rhs)) { db_error("Syntax error\n"); /*NOTREACHED*/ } if (rhs < 0) { db_error("Negative shift amount\n"); /*NOTREACHED*/ } if (t == tSHIFT_L) lhs <<= rhs; else { /* Shift right is unsigned */ lhs = (unsigned) lhs >> rhs; } t = db_read_token(); } db_unread_token(t); *valuep = lhs; return (TRUE); } int db_expression(db_expr_t *valuep) { return (db_shift_expr(valuep)); }