1 /* $NetBSD: parser1.c,v 1.6 2003/08/07 11:17:28 agc Exp $ */ 2 3 /* 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Edward Wang at The University of California, Berkeley. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)parser1.c 8.1 (Berkeley) 6/6/93"; 39 #else 40 __RCSID("$NetBSD: parser1.c,v 1.6 2003/08/07 11:17:28 agc Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 #include "defs.h" 45 #include "parser.h" 46 47 void 48 p_start(void) 49 { 50 char flag = 1; 51 52 (void) s_gettok(); 53 for (;;) { 54 p_statementlist(flag); 55 if (token == T_EOF || p_abort()) 56 break; 57 flag = 0; 58 p_synerror(); 59 while (token != T_EOL && token != T_EOF) { 60 if (token == T_STR) 61 str_free(token_str); 62 (void) s_gettok(); 63 } 64 if (token == T_EOL) 65 (void) s_gettok(); 66 p_clearerr(); 67 } 68 } 69 70 void 71 p_statementlist(char flag) 72 { 73 for (; p_statement(flag) >= 0; p_clearerr()) 74 ; 75 } 76 77 int 78 p_statement(char flag) 79 { 80 switch (token) { 81 case T_EOL: 82 (void) s_gettok(); 83 return 0; 84 case T_IF: 85 return p_if(flag); 86 default: 87 return p_expression(flag); 88 } 89 } 90 91 int 92 p_if(char flag) 93 { 94 struct value t; 95 char true = 0; 96 97 top: 98 (void) s_gettok(); 99 100 if (p_expr(&t, flag) < 0) { 101 p_synerror(); 102 return -1; 103 } 104 switch (t.v_type) { 105 case V_NUM: 106 true = !true && t.v_num != 0; 107 break; 108 case V_STR: 109 p_error("if: Numeric value required."); 110 str_free(t.v_str); 111 case V_ERR: 112 flag = 0; 113 break; 114 } 115 116 if (token != T_THEN) { 117 p_synerror(); 118 return -1; 119 } 120 121 (void) s_gettok(); 122 p_statementlist(flag && true); 123 if (p_erred()) 124 return -1; 125 126 if (token == T_ELSIF) 127 goto top; 128 129 if (token == T_ELSE) { 130 (void) s_gettok(); 131 p_statementlist(flag && !true); 132 if (p_erred()) 133 return -1; 134 } 135 136 if (token == T_ENDIF) { 137 (void) s_gettok(); 138 return 0; 139 } 140 141 p_synerror(); 142 return -1; 143 } 144 145 int 146 p_expression(char flag) 147 { 148 struct value t; 149 char *cmd; 150 151 switch (token) { 152 case T_NUM: 153 t.v_type = V_NUM; 154 t.v_num = token_num; 155 (void) s_gettok(); 156 break; 157 case T_STR: 158 t.v_type = V_STR; 159 t.v_str = token_str; 160 (void) s_gettok(); 161 break; 162 default: 163 if (p_expr(&t, flag) < 0) 164 return -1; 165 if (token == T_EOF) { 166 val_free(t); 167 return 0; 168 } 169 } 170 if (token != T_ASSIGN && p_convstr(&t) < 0) 171 return -1; 172 cmd = t.v_type == V_STR ? t.v_str : 0; 173 if ((*(token == T_ASSIGN ? p_assign : p_function))(cmd, &t, flag) < 0) { 174 if (cmd) 175 str_free(cmd); 176 return -1; 177 } 178 if (cmd) 179 str_free(cmd); 180 val_free(t); 181 if (token == T_EOL) 182 (void) s_gettok(); 183 else if (token != T_EOF) { 184 p_synerror(); 185 return -1; 186 } 187 return 0; 188 } 189 190 int 191 p_convstr(struct value *v) 192 { 193 if (v->v_type != V_NUM) 194 return 0; 195 if ((v->v_str = str_itoa(v->v_num)) == 0) { 196 p_memerror(); 197 v->v_type = V_ERR; 198 return -1; 199 } 200 v->v_type = V_STR; 201 return 0; 202 } 203 204 void 205 p_synerror(void) 206 { 207 if (!cx.x_synerred) { 208 cx.x_synerred = cx.x_erred = 1; 209 error("Syntax error."); 210 } 211 } 212 213 void 214 p_error(const char *msg, ...) 215 { 216 va_list ap; 217 218 va_start(ap, msg); 219 if (!cx.x_erred) { 220 cx.x_erred = 1; 221 verror(msg, ap); 222 } 223 va_end(ap); 224 } 225 226 void 227 p_memerror(void) 228 { 229 cx.x_erred = cx.x_abort = 1; 230 error("Out of memory."); 231 } 232