1 /* $OpenBSD: parsevar.c,v 1.14 2010/07/19 19:46:44 espie Exp $ */ 2 /* $NetBSD: parse.c,v 1.29 1997/03/10 21:20:04 christos Exp $ */ 3 4 /* 5 * Copyright (c) 2001 Marc Espie. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBSD 20 * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <ctype.h> 30 #include <stddef.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include "config.h" 34 #include "defines.h" 35 #include "var.h" 36 #include "varname.h" 37 #include "error.h" 38 #include "cmd_exec.h" 39 #include "parsevar.h" 40 41 static const char *find_op1(const char *); 42 static const char *find_op2(const char *); 43 static bool parse_variable_assignment(const char *, int); 44 45 static const char * 46 find_op1(const char *p) 47 { 48 for(;; p++) { 49 if (isspace(*p) || *p == '$' || *p == '\0') 50 break; 51 if (p[strspn(p, "?:!+")] == '=') 52 break; 53 if (p[0] == ':' && p[1] == 's' && p[2] == 'h') 54 break; 55 } 56 return p; 57 } 58 59 static const char * 60 find_op2(const char *p) 61 { 62 for(;; p++) { 63 if (isspace(*p) || *p == '$' || *p == '\0') 64 break; 65 if (p[strspn(p, "?:!+")] == '=') 66 break; 67 } 68 return p; 69 } 70 71 static bool 72 parse_variable_assignment(const char *line, int ctxt) 73 { 74 const char *arg; 75 char *res1 = NULL, *res2 = NULL; 76 #define VAR_INVALID -1 77 #define VAR_NORMAL 0 78 #define VAR_SUBST 1 79 #define VAR_APPEND 2 80 #define VAR_SHELL 4 81 #define VAR_OPT 8 82 int type; 83 struct Name name; 84 85 arg = VarName_Get(line, &name, NULL, true, 86 FEATURES(FEATURE_SUNSHCMD) ? find_op1 : find_op2); 87 88 while (isspace(*arg)) 89 arg++; 90 91 type = VAR_NORMAL; 92 93 while (*arg != '=') { 94 /* Check operator type. */ 95 switch (*arg++) { 96 case '+': 97 if (type & (VAR_OPT|VAR_APPEND)) 98 type = VAR_INVALID; 99 else 100 type |= VAR_APPEND; 101 break; 102 103 case '?': 104 if (type & (VAR_OPT|VAR_APPEND)) 105 type = VAR_INVALID; 106 else 107 type |= VAR_OPT; 108 break; 109 110 case ':': 111 if (FEATURES(FEATURE_SUNSHCMD) && 112 strncmp(arg, "sh", 2) == 0) { 113 type = VAR_SHELL; 114 arg += 2; 115 while (*arg != '=' && *arg != '\0') 116 arg++; 117 } else { 118 if (type & VAR_SUBST) 119 type = VAR_INVALID; 120 else 121 type |= VAR_SUBST; 122 } 123 break; 124 125 case '!': 126 if (type & VAR_SHELL) 127 type = VAR_INVALID; 128 else 129 type |= VAR_SHELL; 130 break; 131 132 default: 133 type = VAR_INVALID; 134 break; 135 } 136 if (type == VAR_INVALID) { 137 VarName_Free(&name); 138 return false; 139 } 140 } 141 142 arg++; 143 while (isspace(*arg)) 144 arg++; 145 /* If the variable already has a value, we don't do anything. */ 146 if ((type & VAR_OPT) && Var_Definedi(name.s, name.e)) { 147 VarName_Free(&name); 148 return true; 149 } 150 if (type & VAR_SHELL) { 151 char *err; 152 153 if (strchr(arg, '$') != NULL) { 154 char *sub; 155 /* There's a dollar sign in the command, so perform 156 * variable expansion on the whole thing. */ 157 sub = Var_Subst(arg, NULL, true); 158 res1 = Cmd_Exec(sub, &err); 159 free(sub); 160 } else 161 res1 = Cmd_Exec(arg, &err); 162 163 if (err) 164 Parse_Error(PARSE_WARNING, err, arg); 165 arg = res1; 166 } 167 if (type & VAR_SUBST) { 168 /* 169 * Allow variables in the old value to be undefined, but leave 170 * their invocation alone -- this is done by forcing 171 * errorIsOkay to be false. 172 * XXX: This can cause recursive variables, but that's not 173 * hard to do, and this allows someone to do something like 174 * 175 * CFLAGS = $(.INCLUDES) 176 * CFLAGS := -I.. $(CFLAGS) 177 * 178 * And not get an error. 179 */ 180 bool saved = errorIsOkay; 181 182 errorIsOkay = false; 183 /* ensure the variable is set to something to avoid `variable 184 * is recursive' errors. */ 185 if (!Var_Definedi(name.s, name.e)) 186 Var_Seti_with_ctxt(name.s, name.e, "", ctxt); 187 188 res2 = Var_Subst(arg, NULL, false); 189 errorIsOkay = saved; 190 191 arg = res2; 192 } 193 194 if (type & VAR_APPEND) 195 Var_Appendi_with_ctxt(name.s, name.e, arg, ctxt); 196 else 197 Var_Seti_with_ctxt(name.s, name.e, arg, ctxt); 198 199 VarName_Free(&name); 200 free(res2); 201 free(res1); 202 return true; 203 } 204 205 bool 206 Parse_As_Var_Assignment(const char *line) 207 { 208 return parse_variable_assignment(line, VAR_GLOBAL); 209 } 210 211 bool 212 Parse_CmdlineVar(const char *line) 213 { 214 bool result; 215 bool saved = errorIsOkay; 216 217 errorIsOkay = false; 218 result = parse_variable_assignment(line, VAR_CMD); 219 errorIsOkay = saved; 220 return result; 221 } 222 223