1 /*
2  * Much of the design is taken from doas (parse.y rev 1.29)
3  *
4  * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
5  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  *
19  */
20 
21 %{
22 
23 #include "telescope.h"
24 
25 #include <ctype.h>
26 #include <limits.h>
27 #include <stdarg.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 
32 typedef struct {
33 	union {
34 		char	*str;
35 		int	 num;
36 	};
37 	int lineno;
38 	int colno;
39 } yystype;
40 #define YYSTYPE yystype
41 
42 static const char *path;
43 
44 FILE *yyfp;
45 
46 int parse_errors = 0;
47 
48 static void yyerror(const char *, ...);
49 static int yylex(void);
50 
51 %}
52 
53 %token TSET
54 %token TSTYLE TPRFX TCONT TBG TFG TATTR TBOLD TUNDERLINE
55 %token TBIND TUNBIND
56 
57 %token <str> TSTRING
58 %token <num> TNUMBER
59 
60 %%
61 
62 grammar		: /* empty */
63 		| grammar '\n'
64 		| grammar rule '\n'
65 		| error '\n'
66 		;
67 
68 rule		: set | style | bind | unbind ;
69 
70 set		: TSET TSTRING '=' TSTRING	{ printf("set %s = \"%s\"\n", $2, $4); }
71 		| TSET TSTRING '=' TNUMBER	{ printf("set %s = %d\n", $2, $4); }
72 		;
73 
74 style		: TSTYLE TSTRING { printf("(%s) ", $2); }	styleopt
75 		| TSTYLE TSTRING { printf("[%s]\n", $2); }	'{' styleopts '}'
76 		;
77 
78 styleopts	: /* empty */
79 		| styleopts '\n'
80 		| styleopts styleopt '\n'
81 		;
82 
83 styleopt	: TPRFX TSTRING			{ printf("style prefix setted to \"%s\"\n", $2); }
84 		| TCONT TSTRING			{ printf("style cont setted to \"%s\"\n", $2); }
85 		| TBG TSTRING			{ printf("style background setted to \"%s\"\n", $2); }
86 		| TFG TSTRING			{ printf("style foreground setted to \"%s\"\n", $2); }
87 		| TATTR TBOLD			{ printf("style attr setted to bold\n"); }
88 		| TATTR TUNDERLINE		{ printf("style attr setted to underline\n"); }
89 		;
90 
91 bind		: TBIND TSTRING TSTRING TSTRING	{ printf("TODO: bind %s %s %s\n", $2, $3, $4); }
92 		;
93 
94 unbind		: TUNBIND TSTRING TSTRING	{ printf("TODO: unbind %s %s\n", $2, $3); }
95 		;
96 
97 %%
98 
99 void
100 yyerror(const char *fmt, ...)
101 {
102 	va_list va;
103 
104 	fprintf(stderr, "%s:%d ", path, yylval.lineno+1);
105 	va_start(va, fmt);
106 	vfprintf(stderr, fmt, va);
107 	va_end(va);
108 	fprintf(stderr, "\n");
109 	parse_errors++;
110 }
111 
112 static struct keyword {
113 	const char *word;
114 	int token;
115 } keywords[] = {
116 	{ "set", TSET },
117 	{ "style", TSTYLE },
118 	{ "prefix", TPRFX },
119 	{ "cont", TCONT },
120 	{ "background", TBG },
121 	{ "foreground", TFG },
122 	{ "attr", TATTR },
123 	{ "bold", TBOLD },
124 	{ "underline", TUNDERLINE },
125 	{ "bind", TBIND },
126 	{ "unbind", TUNBIND },
127 };
128 
129 int
130 yylex(void)
131 {
132 	char buf[1024], *ebuf, *p, *str;
133 	const char *errstr;
134 	int c, quotes = 0, escape = 0, qpos = -1, nonkw = 0;
135 	size_t i;
136 
137 	p = buf;
138 	ebuf = buf + sizeof(buf);
139 
140 repeat:
141 	/* skip whitespace first */
142 	for (c = getc(yyfp); c == ' ' || c == '\t' || c == '\f'; c = getc(yyfp))
143 		yylval.colno++;
144 
145 	/* check for special one-character constructions */
146 	switch (c) {
147 	case '\n':
148 		yylval.colno = 0;
149 		yylval.lineno++;
150 		/* fallthrough */
151 	case '{':
152 	case '}':
153 	case '=':
154 		return c;
155 	case '#':
156 		/* skip comments; NUL is allowed; no continuation */
157 		while ((c = getc(yyfp)) != '\n')
158 			if (c == EOF)
159 				goto eof;
160 		yylval.colno = 0;
161 		yylval.lineno++;
162 		return c;
163 	case EOF:
164 		goto eof;
165 	}
166 
167 	/* parsing next word */
168 	for (;; c = getc(yyfp), yylval.colno++) {
169 		switch (c) {
170 		case '\0':
171 			yyerror("unallowed character NULL in column %d",
172 			    yylval.colno+1);
173 			escape = 0;
174 			continue;
175 		case '\\':
176 			escape = !escape;
177 			if (escape)
178 				continue;
179 			break;
180 		case '\n':
181 			if (quotes)
182 				yyerror("unterminated quotes in column %d",
183 				    yylval.colno+1);
184 			if (escape) {
185 				nonkw = 1;
186 				escape = 0;
187 				yylval.colno = 0;
188 				yylval.lineno++;
189 			}
190 			goto eow;
191 		case EOF:
192 			if (escape)
193 				yyerror("unterminated escape in column %d",
194 				    yylval.colno);
195 			if (quotes)
196 				yyerror("unterminated quotes in column %d",
197 				    qpos + 1);
198 			goto eow;
199 		case '{':
200 		case '}':
201 		case '=':
202 		case '#':
203 		case ' ':
204 		case '\t':
205 			if (!escape && !quotes)
206 				goto eow;
207 			break;
208 		case '"':
209 			if (!escape) {
210 				quotes = !quotes;
211 				if (quotes) {
212 					nonkw = 1;
213 					qpos = yylval.colno;
214 				}
215 				continue;
216 			}
217 		}
218 		*p++ = c;
219 		if (p == ebuf) {
220 			yyerror("line too long");
221 			p = buf;
222 		}
223 		escape = 0;
224 	}
225 
226 eow:
227 	*p = 0;
228 	if (c != EOF)
229 		ungetc(c, yyfp);
230 	if (p == buf) {
231 		/*
232 		 * There could be a number of reason for empty buffer,
233 		 * and we handle all of them here, to avoid cluttering
234 		 * the main loop.
235 		 */
236 		if (c == EOF)
237 			goto eof;
238 		else if (qpos == -1) /* accept, e.g., empty args: cmd foo args "" */
239 			goto repeat;
240 	}
241 	if (!nonkw) {
242 		for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) {
243 			if (strcmp(buf, keywords[i].word) == 0)
244 				return keywords[i].token;
245 		}
246 	}
247 	c = *buf;
248 	if (!nonkw && (c == '-' || isdigit(c))) {
249 		yylval.num = strtonum(buf, INT_MIN, INT_MAX, &errstr);
250 		if (errstr != NULL)
251 			yyerror("number is %s: %s", errstr, buf);
252 		return TNUMBER;
253 	}
254 	if ((str = strdup(buf)) == NULL)
255 		err(1, "%s", __func__);
256 	yylval.str = str;
257 	return TSTRING;
258 
259 eof:
260 	if (ferror(yyfp))
261 		yyerror("input error reading config");
262 	return 0;
263 }
264 
265 void
266 parseconfig(const char *filename, int fonf)
267 {
268 	if ((yyfp = fopen(filename, "r")) == NULL) {
269 		if (fonf)
270 			err(1, "%s", filename);
271 		return;
272 	}
273 
274 	path = filename;
275 	yyparse();
276 	fclose(yyfp);
277 	if (parse_errors)
278 		exit(1);
279 }