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 <assert.h>
26 #include <ctype.h>
27 #include <limits.h>
28 #include <ncurses.h>
29 #include <stdarg.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 
34 typedef struct {
35 	union {
36 		char	*str;
37 		int	 num;
38 	};
39 	int lineno;
40 	int colno;
41 } yystype;
42 #define YYSTYPE yystype
43 
44 static char *current_style;
45 static int current_bg, current_fg;
46 
47 static const char *path;
48 
49 FILE *yyfp;
50 
51 int parse_errors = 0;
52 
53 static void yyerror(const char *, ...);
54 static int yylex(void);
55 static void setprfx(int, const char *);
56 static void setvari(char *, int);
57 static void setvars(char *, char *);
58 static int colorname(const char *);
59 static void setcolor(int, int, const char *);
60 
61 %}
62 
63 %token TSET
64 %token TSTYLE TPRFX TCONT TBG TFG TATTR TBOLD TUNDERLINE
65 %token TBIND TUNBIND
66 
67 %token <str> TSTRING
68 %token <num> TNUMBER
69 
70 %%
71 
72 grammar		: /* empty */
73 		| grammar '\n'
74 		| grammar rule '\n'
75 		| error '\n'
76 		;
77 
78 rule		: set
79 		| style {
80 			free(current_style);
81 			current_style = NULL;
82 		}
83 		| bind
84 		| unbind
85 		;
86 
87 set		: TSET TSTRING '=' TSTRING	{ setvars($2, $4); }
88 		| TSET TSTRING '=' TNUMBER	{ setvari($2, $4); }
89 		;
90 
91 style		: TSTYLE TSTRING { current_style = $2; } stylespec ;
92 stylespec	: styleopt | '{' styleopts '}' ;
93 
94 styleopts	: /* empty */
95 		| styleopts '\n'
96 		| styleopts styleopt '\n'
97 		;
98 
99 styleopt	: TPRFX TSTRING	{ setprfx(0, $2); }
100 		| TCONT TSTRING	{ setprfx(1, $2); }
101 		| TBG TSTRING {
102 			setcolor(0, 1, $2);
103 			setcolor(1, 1, $2);
104 			free($2);
105 		}
106 		| TFG TSTRING {
107 			setcolor(0, 0, $2);
108 			setcolor(1, 0, $2);
109 			free($2);
110 		}
111 		| TATTR TBOLD			{ printf("style attr setted to bold\n"); }
112 		| TATTR TUNDERLINE		{ printf("style attr setted to underline\n"); }
113 		;
114 
115 bind		: TBIND TSTRING TSTRING TSTRING	{ printf("TODO: bind %s %s %s\n", $2, $3, $4); }
116 		;
117 
118 unbind		: TUNBIND TSTRING TSTRING	{ printf("TODO: unbind %s %s\n", $2, $3); }
119 		;
120 
121 %%
122 
123 void
124 yyerror(const char *fmt, ...)
125 {
126 	va_list va;
127 
128 	fprintf(stderr, "%s:%d ", path, yylval.lineno+1);
129 	va_start(va, fmt);
130 	vfprintf(stderr, fmt, va);
131 	va_end(va);
132 	fprintf(stderr, "\n");
133 	parse_errors++;
134 }
135 
136 static struct keyword {
137 	const char *word;
138 	int token;
139 } keywords[] = {
140 	{ "set", TSET },
141 	{ "style", TSTYLE },
142 	{ "prefix", TPRFX },
143 	{ "cont", TCONT },
144 	{ "bg", TBG },
145 	{ "fg", TFG },
146 	{ "attr", TATTR },
147 	{ "bold", TBOLD },
148 	{ "underline", TUNDERLINE },
149 	{ "bind", TBIND },
150 	{ "unbind", TUNBIND },
151 };
152 
153 int
154 yylex(void)
155 {
156 	char buf[1024], *ebuf, *p, *str;
157 	const char *errstr;
158 	int c, quotes = 0, escape = 0, qpos = -1, nonkw = 0;
159 	size_t i;
160 
161 	p = buf;
162 	ebuf = buf + sizeof(buf);
163 
164 repeat:
165 	/* skip whitespace first */
166 	for (c = getc(yyfp); c == ' ' || c == '\t' || c == '\f'; c = getc(yyfp))
167 		yylval.colno++;
168 
169 	/* check for special one-character constructions */
170 	switch (c) {
171 	case '\n':
172 		yylval.colno = 0;
173 		yylval.lineno++;
174 		/* fallthrough */
175 	case '{':
176 	case '}':
177 	case '=':
178 		return c;
179 	case '#':
180 		/* skip comments; NUL is allowed; no continuation */
181 		while ((c = getc(yyfp)) != '\n')
182 			if (c == EOF)
183 				goto eof;
184 		yylval.colno = 0;
185 		yylval.lineno++;
186 		return c;
187 	case EOF:
188 		goto eof;
189 	}
190 
191 	/* parsing next word */
192 	for (;; c = getc(yyfp), yylval.colno++) {
193 		switch (c) {
194 		case '\0':
195 			yyerror("unallowed character NULL in column %d",
196 			    yylval.colno+1);
197 			escape = 0;
198 			continue;
199 		case '\\':
200 			escape = !escape;
201 			if (escape)
202 				continue;
203 			break;
204 		case '\n':
205 			if (quotes)
206 				yyerror("unterminated quotes in column %d",
207 				    yylval.colno+1);
208 			if (escape) {
209 				nonkw = 1;
210 				escape = 0;
211 				yylval.colno = 0;
212 				yylval.lineno++;
213 			}
214 			goto eow;
215 		case EOF:
216 			if (escape)
217 				yyerror("unterminated escape in column %d",
218 				    yylval.colno);
219 			if (quotes)
220 				yyerror("unterminated quotes in column %d",
221 				    qpos + 1);
222 			goto eow;
223 		case '{':
224 		case '}':
225 		case '=':
226 		case '#':
227 		case ' ':
228 		case '\t':
229 			if (!escape && !quotes)
230 				goto eow;
231 			break;
232 		case '"':
233 			if (!escape) {
234 				quotes = !quotes;
235 				if (quotes) {
236 					nonkw = 1;
237 					qpos = yylval.colno;
238 				}
239 				continue;
240 			}
241 		}
242 		*p++ = c;
243 		if (p == ebuf) {
244 			yyerror("line too long");
245 			p = buf;
246 		}
247 		escape = 0;
248 	}
249 
250 eow:
251 	*p = 0;
252 	if (c != EOF)
253 		ungetc(c, yyfp);
254 	if (p == buf) {
255 		/*
256 		 * There could be a number of reason for empty buffer,
257 		 * and we handle all of them here, to avoid cluttering
258 		 * the main loop.
259 		 */
260 		if (c == EOF)
261 			goto eof;
262 		else if (qpos == -1) /* accept, e.g., empty args: cmd foo args "" */
263 			goto repeat;
264 	}
265 	if (!nonkw) {
266 		for (i = 0; i < sizeof(keywords) / sizeof(keywords[0]); i++) {
267 			if (strcmp(buf, keywords[i].word) == 0)
268 				return keywords[i].token;
269 		}
270 	}
271 	c = *buf;
272 	if (!nonkw && (c == '-' || isdigit(c))) {
273 		yylval.num = strtonum(buf, INT_MIN, INT_MAX, &errstr);
274 		if (errstr != NULL)
275 			yyerror("number is %s: %s", errstr, buf);
276 		return TNUMBER;
277 	}
278 	if ((str = strdup(buf)) == NULL)
279 		err(1, "%s", __func__);
280 	yylval.str = str;
281 	return TSTRING;
282 
283 eof:
284 	if (ferror(yyfp))
285 		yyerror("input error reading config");
286 	return 0;
287 }
288 
289 static void
290 setprfx(int cont, const char *name)
291 {
292 	assert(current_style != NULL);
293 
294 	if (!config_setprfx(current_style, cont, name))
295 		yyerror("invalid style %s", name);
296 }
297 
298 static void
299 setvari(char *var, int val)
300 {
301 	if (!config_setvari(var, val))
302 		yyerror("invalid variable or value: %s = %d",
303 		    var, val);
304 
305 	free(var);
306 }
307 
308 static void
309 setvars(char *var, char *val)
310 {
311         if (!config_setvars(var, val))
312 		yyerror("invalid variable or value: %s = \"%s\"",
313 		    var, val);
314 
315 	free(var);
316 }
317 
318 static int
319 colorname(const char *name)
320 {
321 	struct {
322 		const char	*name;
323 		short		 val;
324 	} *i, colors[] = {
325 		{ "default",	0 },
326 		{ "black",	COLOR_BLACK },
327 		{ "red",	COLOR_RED },
328 		{ "green",	COLOR_GREEN },
329 		{ "yellow",	COLOR_YELLOW },
330 		{ "blue",	COLOR_BLUE },
331 		{ "magenta",	COLOR_MAGENTA },
332 		{ "cyan",	COLOR_CYAN },
333 		{ "white",	COLOR_WHITE },
334 		{ NULL, 0 },
335 	};
336 
337 	for (i = colors; i->name != NULL; ++i) {
338 		if (!strcmp(i->name, name))
339 			return i->val;
340 	}
341 
342 	yyerror("unknown color name \"%s\"", name);
343 	return -1;
344 }
345 
346 void
347 setcolor(int prfx, int bg, const char *color)
348 {
349 	int c;
350 
351 	assert(current_style != NULL);
352 
353 	if ((c = colorname(color)) == -1)
354 		return;
355 
356 	if (!config_setcolor(current_style, prfx, bg, c))
357 		yyerror("can't set color \"%s\" for %s", color,
358 		    current_style);
359 }
360 
361 void
362 parseconfig(const char *filename, int fonf)
363 {
364 	/*
365 	char c;
366 	printf("proceed?\n");
367 	read(0, &c, 1);
368 	*/
369 
370 	if ((yyfp = fopen(filename, "r")) == NULL) {
371 		if (fonf)
372 			err(1, "%s", filename);
373 		return;
374 	}
375 
376 	path = filename;
377 	yyparse();
378 	fclose(yyfp);
379 	if (parse_errors)
380 		exit(1);
381 }