1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Edward Wang at The University of California, Berkeley. 7 * 8 * %sccs.include.redist.c% 9 */ 10 11 #ifndef lint 12 static char sccsid[] = "@(#)parser1.c 8.1 (Berkeley) 06/06/93"; 13 #endif /* not lint */ 14 15 #include "parser.h" 16 17 p_start() 18 { 19 char flag = 1; 20 21 (void) s_gettok(); 22 for (;;) { 23 p_statementlist(flag); 24 if (token == T_EOF || p_abort()) 25 break; 26 flag = 0; 27 p_synerror(); 28 while (token != T_EOL && token != T_EOF) { 29 if (token == T_STR) 30 str_free(token_str); 31 (void) s_gettok(); 32 } 33 if (token == T_EOL) 34 (void) s_gettok(); 35 p_clearerr(); 36 } 37 } 38 39 p_statementlist(flag) 40 char flag; 41 { 42 for (; p_statement(flag) >= 0; p_clearerr()) 43 ; 44 } 45 46 p_statement(flag) 47 char flag; 48 { 49 switch (token) { 50 case T_EOL: 51 (void) s_gettok(); 52 return 0; 53 case T_IF: 54 return p_if(flag); 55 default: 56 return p_expression(flag); 57 } 58 } 59 60 p_if(flag) 61 char flag; 62 { 63 struct value t; 64 char true = 0; 65 66 top: 67 (void) s_gettok(); 68 69 if (p_expr(&t, flag) < 0) { 70 p_synerror(); 71 return -1; 72 } 73 switch (t.v_type) { 74 case V_NUM: 75 true = !true && t.v_num != 0; 76 break; 77 case V_STR: 78 p_error("if: Numeric value required."); 79 str_free(t.v_str); 80 case V_ERR: 81 flag = 0; 82 break; 83 } 84 85 if (token != T_THEN) { 86 p_synerror(); 87 return -1; 88 } 89 90 (void) s_gettok(); 91 p_statementlist(flag && true); 92 if (p_erred()) 93 return -1; 94 95 if (token == T_ELSIF) 96 goto top; 97 98 if (token == T_ELSE) { 99 (void) s_gettok(); 100 p_statementlist(flag && !true); 101 if (p_erred()) 102 return -1; 103 } 104 105 if (token == T_ENDIF) { 106 (void) s_gettok(); 107 return 0; 108 } 109 110 p_synerror(); 111 return -1; 112 } 113 114 p_expression(flag) 115 char flag; 116 { 117 struct value t; 118 char *cmd; 119 int p_function(), p_assign(); 120 121 switch (token) { 122 case T_NUM: 123 t.v_type = V_NUM; 124 t.v_num = token_num; 125 (void) s_gettok(); 126 break; 127 case T_STR: 128 t.v_type = V_STR; 129 t.v_str = token_str; 130 (void) s_gettok(); 131 break; 132 default: 133 if (p_expr(&t, flag) < 0) 134 return -1; 135 if (token == T_EOF) { 136 val_free(t); 137 return 0; 138 } 139 } 140 if (token != T_ASSIGN && p_convstr(&t) < 0) 141 return -1; 142 cmd = t.v_type == V_STR ? t.v_str : 0; 143 if ((*(token == T_ASSIGN ? p_assign : p_function))(cmd, &t, flag) < 0) { 144 if (cmd) 145 str_free(cmd); 146 return -1; 147 } 148 if (cmd) 149 str_free(cmd); 150 val_free(t); 151 if (token == T_EOL) 152 (void) s_gettok(); 153 else if (token != T_EOF) { 154 p_synerror(); 155 return -1; 156 } 157 return 0; 158 } 159 160 p_convstr(v) 161 register struct value *v; 162 { 163 if (v->v_type != V_NUM) 164 return 0; 165 if ((v->v_str = str_itoa(v->v_num)) == 0) { 166 p_memerror(); 167 v->v_type = V_ERR; 168 return -1; 169 } 170 v->v_type = V_STR; 171 return 0; 172 } 173 174 p_synerror() 175 { 176 if (!cx.x_synerred) { 177 cx.x_synerred = cx.x_erred = 1; 178 error("Syntax error."); 179 } 180 } 181 182 /*VARARGS1*/ 183 p_error(msg, a, b, c) 184 char *msg; 185 { 186 if (!cx.x_erred) { 187 cx.x_erred = 1; 188 error(msg, a, b, c); 189 } 190 } 191 192 p_memerror() 193 { 194 cx.x_erred = cx.x_abort = 1; 195 error("Out of memory."); 196 } 197