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