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 char *current_style;
43 static const char *path;
44 
45 FILE *yyfp;
46 
47 int parse_errors = 0;
48 
49 static void yyerror(const char *, ...);
50 static int yylex(void);
51 static void setprfx(int, const char *);
52 
53 %}
54 
55 %token TSET
56 %token TSTYLE TPRFX TCONT TBG TFG TATTR TBOLD TUNDERLINE
57 %token TBIND TUNBIND
58 
59 %token <str> TSTRING
60 %token <num> TNUMBER
61 
62 %%
63 
64 grammar		: /* empty */
65 		| grammar '\n'
66 		| grammar rule '\n'
67 		| error '\n'
68 		;
69 
70 rule		: set
71 		| style		{ free(current_style); current_style = NULL; }
72 		| bind
73 		| unbind
74 		;
75 
76 set		: TSET TSTRING '=' TSTRING	{ printf("set %s = \"%s\"\n", $2, $4); }
77 		| TSET TSTRING '=' TNUMBER	{ printf("set %s = %d\n", $2, $4); }
78 		;
79 
80 style		: TSTYLE TSTRING { current_style = $2; } styleopt
81 		| TSTYLE TSTRING { current_style = $2; } '{' styleopts '}'
82 		;
83 
84 styleopts	: /* empty */
85 		| styleopts '\n'
86 		| styleopts styleopt '\n'
87 		;
88 
89 styleopt	: TPRFX TSTRING			{ setprfx(0, $2); }
90 		| TCONT TSTRING			{ setprfx(1, $2); }
91 		| TBG TSTRING			{ printf("style background setted to \"%s\"\n", $2); }
92 		| TFG TSTRING			{ printf("style foreground setted to \"%s\"\n", $2); }
93 		| TATTR TBOLD			{ printf("style attr setted to bold\n"); }
94 		| TATTR TUNDERLINE		{ printf("style attr setted to underline\n"); }
95 		;
96 
97 bind		: TBIND TSTRING TSTRING TSTRING	{ printf("TODO: bind %s %s %s\n", $2, $3, $4); }
98 		;
99 
100 unbind		: TUNBIND TSTRING TSTRING	{ printf("TODO: unbind %s %s\n", $2, $3); }
101 		;
102 
103 %%
104 
105 void
106 yyerror(const char *fmt, ...)
107 {
108 	va_list va;
109 
110 	fprintf(stderr, "%s:%d ", path, yylval.lineno+1);
111 	va_start(va, fmt);
112 	vfprintf(stderr, fmt, va);
113 	va_end(va);
114 	fprintf(stderr, "\n");
115 	parse_errors++;
116 }
117 
118 static struct keyword {
119 	const char *word;
120 	int token;
121 } keywords[] = {
122 	{ "set", TSET },
123 	{ "style", TSTYLE },
124 	{ "prefix", TPRFX },
125 	{ "cont", TCONT },
126 	{ "background", TBG },
127 	{ "foreground", TFG },
128 	{ "attr", TATTR },
129 	{ "bold", TBOLD },
130 	{ "underline", TUNDERLINE },
131 	{ "bind", TBIND },
132 	{ "unbind", TUNBIND },
133 };
134 
135 int
136 yylex(void)
137 {
138 	char buf[1024], *ebuf, *p, *str;
139 	const char *errstr;
140 	int c, quotes = 0, escape = 0, qpos = -1, nonkw = 0;
141 	size_t i;
142 
143 	p = buf;
144 	ebuf = buf + sizeof(buf);
145 
146 repeat:
147 	/* skip whitespace first */
148 	for (c = getc(yyfp); c == ' ' || c == '\t' || c == '\f'; c = getc(yyfp))
149 		yylval.colno++;
150 
151 	/* check for special one-character constructions */
152 	switch (c) {
153 	case '\n':
154 		yylval.colno = 0;
155 		yylval.lineno++;
156 		/* fallthrough */
157 	case '{':
158 	case '}':
159 	case '=':
160 		return c;
161 	case '#':
162 		/* skip comments; NUL is allowed; no continuation */
163 		while ((c = getc(yyfp)) != '\n')
164 			if (c == EOF)
165 				goto eof;
166 		yylval.colno = 0;
167 		yylval.lineno++;
168 		return c;
169 	case EOF:
170 		goto eof;
171 	}
172 
173 	/* parsing next word */
174 	for (;; c = getc(yyfp), yylval.colno++) {
175 		switch (c) {
176 		case '\0':
177 			yyerror("unallowed character NULL in column %d",
178 			    yylval.colno+1);
179 			escape = 0;
180 			continue;
181 		case '\\':
182 			escape = !escape;
183 			if (escape)
184 				continue;
185 			break;
186 		case '\n':
187 			if (quotes)
188 				yyerror("unterminated quotes in column %d",
189 				    yylval.colno+1);
190 			if (escape) {
191 				nonkw = 1;
192 				escape = 0;
193 				yylval.colno = 0;
194 				yylval.lineno++;
195 			}
196 			goto eow;
197 		case EOF:
198 			if (escape)
199 				yyerror("unterminated escape in column %d",
200 				    yylval.colno);
201 			if (quotes)
202 				yyerror("unterminated quotes in column %d",
203 				    qpos + 1);
204 			goto eow;
205 		case '{':
206 		case '}':
207 		case '=':
208 		case '#':
209 		case ' ':
210 		case '\t':
211 			if (!escape && !quotes)
212 				goto eow;
213 			break;
214 		case '"':
215 			if (!escape) {
216 				quotes = !quotes;
217 				if (quotes) {
218 					nonkw = 1;
219 					qpos = yylval.colno;
220 				}
221 				continue;
222 			}
223 		}
224 		*p++ = c;
225 		if (p == ebuf) {
226 			yyerror("line too long");
227 			p = buf;
228 		}
229 		escape = 0;
230 	}
231 
232 eow:
233 	*p = 0;
234 	if (c != EOF)
235 		ungetc(c, yyfp);
236 	if (p == buf) {
237 		/*
238 		 * There could be a number of reason for empty buffer,
239 		 * and we handle all of them here, to avoid cluttering
240 		 * the main loop.
241 		 */
242 		if (c == EOF)
243 			goto eof;
244 		else if (qpos == -1) /* accept, e.g., empty args: cmd foo args "" */
245 			goto repeat;
246 	}
247 	if (!nonkw) {
248 		for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) {
249 			if (strcmp(buf, keywords[i].word) == 0)
250 				return keywords[i].token;
251 		}
252 	}
253 	c = *buf;
254 	if (!nonkw && (c == '-' || isdigit(c))) {
255 		yylval.num = strtonum(buf, INT_MIN, INT_MAX, &errstr);
256 		if (errstr != NULL)
257 			yyerror("number is %s: %s", errstr, buf);
258 		return TNUMBER;
259 	}
260 	if ((str = strdup(buf)) == NULL)
261 		err(1, "%s", __func__);
262 	yylval.str = str;
263 	return TSTRING;
264 
265 eof:
266 	if (ferror(yyfp))
267 		yyerror("input error reading config");
268 	return 0;
269 }
270 
271 static void
272 setprfx(int cont, const char *name)
273 {
274 	if (current_style == NULL) {
275 		warnx("current_style = NULL!");
276 		abort();
277 	}
278 
279 	if (!config_setprfx(current_style, cont, name))
280 		yyerror("invalid style %s", name);
281 }
282 
283 void
284 parseconfig(const char *filename, int fonf)
285 {
286 	if ((yyfp = fopen(filename, "r")) == NULL) {
287 		if (fonf)
288 			err(1, "%s", filename);
289 		return;
290 	}
291 
292 	path = filename;
293 	yyparse();
294 	fclose(yyfp);
295 	if (parse_errors)
296 		exit(1);
297 }