xref: /openbmc/linux/scripts/kconfig/lexer.l (revision fe4549b1)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
4  */
5 %option nostdinit noyywrap never-interactive full ecs
6 %option 8bit nodefault yylineno
7 %x ASSIGN_VAL HELP STRING
8 %{
9 
10 #include <assert.h>
11 #include <limits.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 
16 #include "lkc.h"
17 #include "parser.tab.h"
18 
19 #define YY_DECL		static int yylex1(void)
20 
21 #define START_STRSIZE	16
22 
23 static struct {
24 	struct file *file;
25 	int lineno;
26 } current_pos;
27 
28 static int prev_prev_token = T_EOL;
29 static int prev_token = T_EOL;
30 static char *text;
31 static int text_size, text_asize;
32 
33 struct buffer {
34 	struct buffer *parent;
35 	YY_BUFFER_STATE state;
36 };
37 
38 static struct buffer *current_buf;
39 
40 static int last_ts, first_ts;
41 
42 static char *expand_token(const char *in, size_t n);
43 static void append_expanded_string(const char *in);
44 static void zconf_endhelp(void);
45 static void zconf_endfile(void);
46 
47 static void new_string(void)
48 {
49 	text = xmalloc(START_STRSIZE);
50 	text_asize = START_STRSIZE;
51 	text_size = 0;
52 	*text = 0;
53 }
54 
55 static void append_string(const char *str, int size)
56 {
57 	int new_size = text_size + size + 1;
58 	if (new_size > text_asize) {
59 		new_size += START_STRSIZE - 1;
60 		new_size &= -START_STRSIZE;
61 		text = xrealloc(text, new_size);
62 		text_asize = new_size;
63 	}
64 	memcpy(text + text_size, str, size);
65 	text_size += size;
66 	text[text_size] = 0;
67 }
68 
69 static void alloc_string(const char *str, int size)
70 {
71 	text = xmalloc(size + 1);
72 	memcpy(text, str, size);
73 	text[size] = 0;
74 }
75 
76 static void warn_ignored_character(char chr)
77 {
78 	fprintf(stderr,
79 	        "%s:%d:warning: ignoring unsupported character '%c'\n",
80 	        current_file->name, yylineno, chr);
81 }
82 %}
83 
84 n	[A-Za-z0-9_-]
85 
86 %%
87 	char open_quote = 0;
88 
89 #.*			/* ignore comment */
90 [ \t]*			/* whitespaces */
91 \\\n			/* escaped new line */
92 \n			return T_EOL;
93 "bool"			return T_BOOL;
94 "choice"		return T_CHOICE;
95 "comment"		return T_COMMENT;
96 "config"		return T_CONFIG;
97 "def_bool"		return T_DEF_BOOL;
98 "def_tristate"		return T_DEF_TRISTATE;
99 "default"		return T_DEFAULT;
100 "depends"		return T_DEPENDS;
101 "endchoice"		return T_ENDCHOICE;
102 "endif"			return T_ENDIF;
103 "endmenu"		return T_ENDMENU;
104 "help"			return T_HELP;
105 "hex"			return T_HEX;
106 "if"			return T_IF;
107 "imply"			return T_IMPLY;
108 "int"			return T_INT;
109 "mainmenu"		return T_MAINMENU;
110 "menu"			return T_MENU;
111 "menuconfig"		return T_MENUCONFIG;
112 "modules"		return T_MODULES;
113 "on"			return T_ON;
114 "optional"		return T_OPTIONAL;
115 "prompt"		return T_PROMPT;
116 "range"			return T_RANGE;
117 "select"		return T_SELECT;
118 "source"		return T_SOURCE;
119 "string"		return T_STRING;
120 "tristate"		return T_TRISTATE;
121 "visible"		return T_VISIBLE;
122 "||"			return T_OR;
123 "&&"			return T_AND;
124 "="			return T_EQUAL;
125 "!="			return T_UNEQUAL;
126 "<"			return T_LESS;
127 "<="			return T_LESS_EQUAL;
128 ">"			return T_GREATER;
129 ">="			return T_GREATER_EQUAL;
130 "!"			return T_NOT;
131 "("			return T_OPEN_PAREN;
132 ")"			return T_CLOSE_PAREN;
133 ":="			return T_COLON_EQUAL;
134 "+="			return T_PLUS_EQUAL;
135 \"|\'			{
136 				open_quote = yytext[0];
137 				new_string();
138 				BEGIN(STRING);
139 			}
140 {n}+			{
141 				alloc_string(yytext, yyleng);
142 				yylval.string = text;
143 				return T_WORD;
144 			}
145 ({n}|$)+		{
146 				/* this token includes at least one '$' */
147 				yylval.string = expand_token(yytext, yyleng);
148 				if (strlen(yylval.string))
149 					return T_WORD;
150 				free(yylval.string);
151 			}
152 .			warn_ignored_character(*yytext);
153 
154 <ASSIGN_VAL>{
155 	[^[:blank:]\n]+.*	{
156 		alloc_string(yytext, yyleng);
157 		yylval.string = text;
158 		return T_ASSIGN_VAL;
159 	}
160 	\n	{ BEGIN(INITIAL); return T_EOL; }
161 	.
162 }
163 
164 <STRING>{
165 	"$".*	append_expanded_string(yytext);
166 	[^$'"\\\n]+	{
167 		append_string(yytext, yyleng);
168 	}
169 	\\.?	{
170 		append_string(yytext + 1, yyleng - 1);
171 	}
172 	\'|\"	{
173 		if (open_quote == yytext[0]) {
174 			BEGIN(INITIAL);
175 			yylval.string = text;
176 			return T_WORD_QUOTE;
177 		} else
178 			append_string(yytext, 1);
179 	}
180 	\n	{
181 		fprintf(stderr,
182 			"%s:%d:warning: multi-line strings not supported\n",
183 			zconf_curname(), zconf_lineno());
184 		unput('\n');
185 		BEGIN(INITIAL);
186 		yylval.string = text;
187 		return T_WORD_QUOTE;
188 	}
189 	<<EOF>>	{
190 		BEGIN(INITIAL);
191 		yylval.string = text;
192 		return T_WORD_QUOTE;
193 	}
194 }
195 
196 <HELP>{
197 	[ \t]+	{
198 		int ts, i;
199 
200 		ts = 0;
201 		for (i = 0; i < yyleng; i++) {
202 			if (yytext[i] == '\t')
203 				ts = (ts & ~7) + 8;
204 			else
205 				ts++;
206 		}
207 		last_ts = ts;
208 		if (first_ts) {
209 			if (ts < first_ts) {
210 				zconf_endhelp();
211 				return T_HELPTEXT;
212 			}
213 			ts -= first_ts;
214 			while (ts > 8) {
215 				append_string("        ", 8);
216 				ts -= 8;
217 			}
218 			append_string("        ", ts);
219 		}
220 	}
221 	[ \t]*\n/[^ \t\n] {
222 		zconf_endhelp();
223 		return T_HELPTEXT;
224 	}
225 	[ \t]*\n	{
226 		append_string("\n", 1);
227 	}
228 	[^ \t\n].* {
229 		while (yyleng) {
230 			if ((yytext[yyleng-1] != ' ') && (yytext[yyleng-1] != '\t'))
231 				break;
232 			yyleng--;
233 		}
234 		append_string(yytext, yyleng);
235 		if (!first_ts)
236 			first_ts = last_ts;
237 	}
238 	<<EOF>>	{
239 		zconf_endhelp();
240 		return T_HELPTEXT;
241 	}
242 }
243 
244 <<EOF>>	{
245 	BEGIN(INITIAL);
246 
247 	if (prev_token != T_EOL && prev_token != T_HELPTEXT)
248 		fprintf(stderr, "%s:%d:warning: no new line at end of file\n",
249 			current_file->name, yylineno);
250 
251 	if (current_file) {
252 		zconf_endfile();
253 		return T_EOL;
254 	}
255 	fclose(yyin);
256 	yyterminate();
257 }
258 
259 %%
260 
261 /* second stage lexer */
262 int yylex(void)
263 {
264 	int token;
265 
266 repeat:
267 	token = yylex1();
268 
269 	if (prev_token == T_EOL || prev_token == T_HELPTEXT) {
270 		if (token == T_EOL) {
271 			/* Do not pass unneeded T_EOL to the parser. */
272 			goto repeat;
273 		} else {
274 			/*
275 			 * For the parser, update file/lineno at the first token
276 			 * of each statement. Generally, \n is a statement
277 			 * terminator in Kconfig, but it is not always true
278 			 * because \n could be escaped by a backslash.
279 			 */
280 			current_pos.file = current_file;
281 			current_pos.lineno = yylineno;
282 		}
283 	}
284 
285 	if (prev_prev_token == T_EOL && prev_token == T_WORD &&
286 	    (token == T_EQUAL || token == T_COLON_EQUAL || token == T_PLUS_EQUAL))
287 		BEGIN(ASSIGN_VAL);
288 
289 	prev_prev_token = prev_token;
290 	prev_token = token;
291 
292 	return token;
293 }
294 
295 static char *expand_token(const char *in, size_t n)
296 {
297 	char *out;
298 	int c;
299 	char c2;
300 	const char *rest, *end;
301 
302 	new_string();
303 	append_string(in, n);
304 
305 	/*
306 	 * get the whole line because we do not know the end of token.
307 	 * input() returns 0 (not EOF!) when it reachs the end of file.
308 	 */
309 	while ((c = input()) != 0) {
310 		if (c == '\n') {
311 			unput(c);
312 			break;
313 		}
314 		c2 = c;
315 		append_string(&c2, 1);
316 	}
317 
318 	rest = text;
319 	out = expand_one_token(&rest);
320 
321 	/* push back unused characters to the input stream */
322 	end = rest + strlen(rest);
323 	while (end > rest)
324 		unput(*--end);
325 
326 	free(text);
327 
328 	return out;
329 }
330 
331 static void append_expanded_string(const char *str)
332 {
333 	const char *end;
334 	char *res;
335 
336 	str++;
337 
338 	res = expand_dollar(&str);
339 
340 	/* push back unused characters to the input stream */
341 	end = str + strlen(str);
342 	while (end > str)
343 		unput(*--end);
344 
345 	append_string(res, strlen(res));
346 
347 	free(res);
348 }
349 
350 void zconf_starthelp(void)
351 {
352 	new_string();
353 	last_ts = first_ts = 0;
354 	BEGIN(HELP);
355 }
356 
357 static void zconf_endhelp(void)
358 {
359 	yylval.string = text;
360 	BEGIN(INITIAL);
361 }
362 
363 
364 /*
365  * Try to open specified file with following names:
366  * ./name
367  * $(srctree)/name
368  * The latter is used when srctree is separate from objtree
369  * when compiling the kernel.
370  * Return NULL if file is not found.
371  */
372 FILE *zconf_fopen(const char *name)
373 {
374 	char *env, fullname[PATH_MAX+1];
375 	FILE *f;
376 
377 	f = fopen(name, "r");
378 	if (!f && name != NULL && name[0] != '/') {
379 		env = getenv(SRCTREE);
380 		if (env) {
381 			snprintf(fullname, sizeof(fullname),
382 				 "%s/%s", env, name);
383 			f = fopen(fullname, "r");
384 		}
385 	}
386 	return f;
387 }
388 
389 void zconf_initscan(const char *name)
390 {
391 	yyin = zconf_fopen(name);
392 	if (!yyin) {
393 		fprintf(stderr, "can't find file %s\n", name);
394 		exit(1);
395 	}
396 
397 	current_buf = xmalloc(sizeof(*current_buf));
398 	memset(current_buf, 0, sizeof(*current_buf));
399 
400 	current_file = file_lookup(name);
401 	yylineno = 1;
402 }
403 
404 void zconf_nextfile(const char *name)
405 {
406 	struct file *iter;
407 	struct file *file = file_lookup(name);
408 	struct buffer *buf = xmalloc(sizeof(*buf));
409 	memset(buf, 0, sizeof(*buf));
410 
411 	current_buf->state = YY_CURRENT_BUFFER;
412 	yyin = zconf_fopen(file->name);
413 	if (!yyin) {
414 		fprintf(stderr, "%s:%d: can't open file \"%s\"\n",
415 			zconf_curname(), zconf_lineno(), file->name);
416 		exit(1);
417 	}
418 	yy_switch_to_buffer(yy_create_buffer(yyin, YY_BUF_SIZE));
419 	buf->parent = current_buf;
420 	current_buf = buf;
421 
422 	current_file->lineno = yylineno;
423 	file->parent = current_file;
424 
425 	for (iter = current_file; iter; iter = iter->parent) {
426 		if (!strcmp(iter->name, file->name)) {
427 			fprintf(stderr,
428 				"Recursive inclusion detected.\n"
429 				"Inclusion path:\n"
430 				"  current file : %s\n", file->name);
431 			iter = file;
432 			do {
433 				iter = iter->parent;
434 				fprintf(stderr, "  included from: %s:%d\n",
435 					iter->name, iter->lineno - 1);
436 			} while (strcmp(iter->name, file->name));
437 			exit(1);
438 		}
439 	}
440 
441 	yylineno = 1;
442 	current_file = file;
443 }
444 
445 static void zconf_endfile(void)
446 {
447 	struct buffer *parent;
448 
449 	current_file = current_file->parent;
450 	if (current_file)
451 		yylineno = current_file->lineno;
452 
453 	parent = current_buf->parent;
454 	if (parent) {
455 		fclose(yyin);
456 		yy_delete_buffer(YY_CURRENT_BUFFER);
457 		yy_switch_to_buffer(parent->state);
458 	}
459 	free(current_buf);
460 	current_buf = parent;
461 }
462 
463 int zconf_lineno(void)
464 {
465 	return current_pos.lineno;
466 }
467 
468 const char *zconf_curname(void)
469 {
470 	return current_pos.file ? current_pos.file->name : "<none>";
471 }
472