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MFC r338120: config(8): Allow escape-quoted empty strings
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1 %{
2 /*-
3  * Copyright (c) 1980, 1993
4  *      The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 4. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *      @(#)lang.l      8.1 (Berkeley) 6/6/93
31  * $FreeBSD$
32  */
33
34 #include <assert.h>
35 #include <ctype.h>
36 #include <err.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include "y.tab.h"
40 #include "config.h"
41
42 /*
43  * Data for returning to previous files from include files.
44  */
45 struct incl {
46         struct  incl *in_prev;  /* previous includes in effect, if any */
47         YY_BUFFER_STATE in_buf; /* previous lex state */
48         const   char *in_fname; /* previous file name */
49         int     in_lineno;      /* previous line number */
50         int     in_ateof;       /* token to insert at EOF */
51 };
52 static struct   incl *inclp;
53 static const    char *lastfile;
54
55 /*
56  * Key word table
57  */
58
59 struct kt {
60         const char *kt_name;
61         int kt_val;
62 } key_words[] = {
63         { "config",     CONFIG },
64         { "cpu",        CPU },
65         { "nocpu",      NOCPU },
66         { "device",     DEVICE },
67         { "devices",    DEVICE },
68         { "nodevice",   NODEVICE },
69         { "nodevices",  NODEVICE },
70         { "env",        ENV },
71         { "hints",      HINTS },
72         { "ident",      IDENT },
73         { "machine",    ARCH }, /* MACHINE is defined in /sys/param.h */
74         { "makeoption", MAKEOPTIONS },
75         { "makeoptions", MAKEOPTIONS },
76         { "nomakeoption", NOMAKEOPTION },
77         { "nomakeoptions", NOMAKEOPTION },
78         { "maxusers",   MAXUSERS },
79         { "profile",    PROFILE },
80         { "option",     OPTIONS },
81         { "options",    OPTIONS },
82         { "nooption",   NOOPTION },
83         { "nooptions",  NOOPTION },
84         { "include",    INCLUDE },
85         { "files",      FILES },
86         { 0, 0 },
87 };
88
89
90 static int endinclude(void);
91 int include(const char *, int);
92 int kw_lookup(char *);
93 unsigned int octal(const char *);
94 unsigned int hex(const char *);
95 int yyerror(const char *);
96
97 #define YY_DECL int yylex(void)
98 %}
99
100 %option nounput
101 %option noinput
102
103 ID      [A-Za-z_][-A-Za-z_0-9]*
104 PATH    [./][-/.%^A-Za-z_0-9]+
105 %START TOEOL
106 %%
107 {ID}            {
108                         int i;
109
110                         BEGIN 0;
111                         if ((i = kw_lookup(yytext)) == -1)
112                         {
113                                 yylval.str = strdup(yytext);
114                                 return ID;
115                         }
116                         return i;
117                 }
118 \\\"[^"]*\\\"   {
119                         BEGIN 0;
120                         yytext[yyleng-2] = '"';
121                         yytext[yyleng-1] = '\0';
122                         yylval.str = strdup(yytext + 1);
123                         return ID;
124                 }
125 \"[^"]+\"       {
126                         BEGIN 0;
127                         yytext[yyleng-1] = '\0';
128                         yylval.str = strdup(yytext + 1);
129                         return ID;
130                 }
131 <TOEOL>[^# \t\n]*       {
132                         BEGIN 0;
133                         yylval.str = strdup(yytext);
134                         return ID;
135                 }
136 0[0-7]*         {
137                         yylval.val = octal(yytext);
138                         return NUMBER;
139                 }
140 0x[0-9a-fA-F]+  {
141                         yylval.val = hex(yytext);
142                         return NUMBER;
143                 }
144 -?[1-9][0-9]*   {
145                         yylval.val = atoi(yytext);
146                         return NUMBER;
147                 }
148 "?"             {
149                         yylval.val = -1;
150                         return NUMBER;
151                 }
152 \n/[ \t]        {
153                         yyline++;
154                 }
155 \n              {
156                         yyline++;
157                         return SEMICOLON;
158                 }
159 #.*             {       /* Ignored (comment) */;        }
160 [ \t\f]*        {       /* Ignored (white space) */;    }
161 ";"             {       return SEMICOLON;               }
162 ","             {       return COMMA;                   }
163 "="             {       BEGIN TOEOL; return EQUALS;     }
164 "+="            {       BEGIN TOEOL; return PLUSEQUALS; }
165 <<EOF>>         {
166                         int tok;
167
168                         if (inclp == NULL)
169                                 return YY_NULL;
170                         tok = endinclude();
171                         if (tok != 0)
172                                 return tok;
173                         /* otherwise continue scanning */
174                 }
175 {PATH}          {
176                         BEGIN 0;
177                         yylval.str = strdup(yytext);
178                         return PATH;
179                 }
180 .               {       return yytext[0];               }
181
182 %%
183 /*
184  * kw_lookup
185  *      Look up a string in the keyword table.  Returns a -1 if the
186  *      string is not a keyword otherwise it returns the keyword number
187  */
188
189 int
190 kw_lookup(char *word)
191 {
192         struct kt *kp;
193
194         for (kp = key_words; kp->kt_name != 0; kp++)
195                 if (eq(word, kp->kt_name))
196                         return kp->kt_val;
197         return -1;
198 }
199
200 /*
201  * Number conversion routines
202  */
203
204 unsigned int
205 octal(const char *str)
206 {
207         unsigned int num;
208
209         (void) sscanf(str, "%o", &num);
210         return num;
211 }
212
213 unsigned int
214 hex(const char *str)
215 {
216         unsigned int num;
217
218         (void) sscanf(str+2, "%x", &num);
219         return num;
220 }
221
222 void
223 cfgfile_add(const char *fname)
224 {
225         struct cfgfile *cf;
226
227         cf = calloc(1, sizeof(*cf));
228         if (cf == NULL)
229                 err(EXIT_FAILURE, "calloc");
230         assert(cf != NULL);
231         asprintf(&cf->cfg_path, "%s", fname);
232         STAILQ_INSERT_TAIL(&cfgfiles, cf, cfg_next);
233 }
234
235 void
236 cfgfile_removeall(void)
237 {
238         struct cfgfile *cf;
239
240         while (!STAILQ_EMPTY(&cfgfiles)) {
241                 cf = STAILQ_FIRST(&cfgfiles);
242                 STAILQ_REMOVE_HEAD(&cfgfiles, cfg_next);
243                 if (cf->cfg_path != NULL)
244                         free(cf->cfg_path);
245                 free(cf);
246         }
247 }
248
249 /*
250  * Open the named file for inclusion at the current point.  Returns 0 on
251  * success (file opened and previous state pushed), nonzero on failure
252  * (fopen failed, complaint made).  The `ateof' parameter controls the
253  * token to be inserted at the end of the include file. If ateof == 0,
254  * then nothing is inserted.
255  */
256 int
257 include(const char *fname, int ateof)
258 {
259         FILE *fp;
260         struct incl *in;
261         struct includepath* ipath;
262         char *fnamebuf;
263
264         fnamebuf = NULL;
265         fp = fopen(fname, "r");
266         if (fp == NULL && fname[0] != '.' && fname[0] != '/') {
267                 asprintf(&fnamebuf, "../../conf/%s", fname);
268                 if (fnamebuf != NULL) {
269                         fp = fopen(fnamebuf, "r");
270                         if (fp == NULL)
271                                 free(fnamebuf);
272                 }
273         }
274         if (fp == NULL) {
275                 SLIST_FOREACH(ipath, &includepath, path_next) {
276                         asprintf(&fnamebuf, "%s/%s", ipath->path, fname);
277                         if (fnamebuf != NULL) {
278                                 fp = fopen(fnamebuf, "r");
279                         }
280                         if (fp != NULL)
281                                 break;
282                         free(fnamebuf);
283                 }
284         }
285         if (fp == NULL) {
286                 yyerror("cannot open included file");
287                 return (-1);
288         }
289         cfgfile_add(fnamebuf == NULL ? fname : fnamebuf);
290         in = malloc(sizeof(*in));
291         assert(in != NULL);
292         in->in_prev = inclp;
293         in->in_buf = YY_CURRENT_BUFFER;
294         in->in_fname = yyfile;
295         in->in_lineno = yyline;
296         in->in_ateof = ateof;
297         inclp = in;
298         yy_switch_to_buffer(yy_create_buffer(fp, YY_BUF_SIZE));
299         yyfile = fname;
300         yyline = 0;
301         return (0);
302 }
303
304 /*
305  * Terminate the most recent inclusion.
306  */
307 static int
308 endinclude(void)
309 {
310         struct incl *in;
311         int ateof;
312
313         in = inclp;
314         assert(in != NULL);
315         inclp = in->in_prev;
316         lastfile = yyfile;
317         yy_delete_buffer(YY_CURRENT_BUFFER);
318         (void)fclose(yyin);
319         yy_switch_to_buffer(in->in_buf);
320         yyfile = in->in_fname;
321         yyline = in->in_lineno;
322         ateof  = in->in_ateof;
323         free(in);
324
325         return (ateof);
326 }