xref: /linux/scripts/kconfig/lexer.l (revision 662fa3d6099374c4615bf64d06895e3573b935b2)
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 	int str = 0;
88 	int ts, i;
89 
90 #.*			/* ignore comment */
91 [ \t]*			/* whitespaces */
92 \\\n			/* escaped new line */
93 \n			return T_EOL;
94 "bool"			return T_BOOL;
95 "choice"		return T_CHOICE;
96 "comment"		return T_COMMENT;
97 "config"		return T_CONFIG;
98 "def_bool"		return T_DEF_BOOL;
99 "def_tristate"		return T_DEF_TRISTATE;
100 "default"		return T_DEFAULT;
101 "depends"		return T_DEPENDS;
102 "endchoice"		return T_ENDCHOICE;
103 "endif"			return T_ENDIF;
104 "endmenu"		return T_ENDMENU;
105 "help"			return T_HELP;
106 "hex"			return T_HEX;
107 "if"			return T_IF;
108 "imply"			return T_IMPLY;
109 "int"			return T_INT;
110 "mainmenu"		return T_MAINMENU;
111 "menu"			return T_MENU;
112 "menuconfig"		return T_MENUCONFIG;
113 "modules"		return T_MODULES;
114 "on"			return T_ON;
115 "optional"		return T_OPTIONAL;
116 "prompt"		return T_PROMPT;
117 "range"			return T_RANGE;
118 "select"		return T_SELECT;
119 "source"		return T_SOURCE;
120 "string"		return T_STRING;
121 "tristate"		return T_TRISTATE;
122 "visible"		return T_VISIBLE;
123 "||"			return T_OR;
124 "&&"			return T_AND;
125 "="			return T_EQUAL;
126 "!="			return T_UNEQUAL;
127 "<"			return T_LESS;
128 "<="			return T_LESS_EQUAL;
129 ">"			return T_GREATER;
130 ">="			return T_GREATER_EQUAL;
131 "!"			return T_NOT;
132 "("			return T_OPEN_PAREN;
133 ")"			return T_CLOSE_PAREN;
134 ":="			return T_COLON_EQUAL;
135 "+="			return T_PLUS_EQUAL;
136 \"|\'			{
137 				str = yytext[0];
138 				new_string();
139 				BEGIN(STRING);
140 			}
141 {n}+			{
142 				alloc_string(yytext, yyleng);
143 				yylval.string = text;
144 				return T_WORD;
145 			}
146 ({n}|$)+		{
147 				/* this token includes at least one '$' */
148 				yylval.string = expand_token(yytext, yyleng);
149 				if (strlen(yylval.string))
150 					return T_WORD;
151 				free(yylval.string);
152 			}
153 .			warn_ignored_character(*yytext);
154 
155 <ASSIGN_VAL>{
156 	[^[:blank:]\n]+.*	{
157 		alloc_string(yytext, yyleng);
158 		yylval.string = text;
159 		return T_ASSIGN_VAL;
160 	}
161 	\n	{ BEGIN(INITIAL); return T_EOL; }
162 	.
163 }
164 
165 <STRING>{
166 	"$".*	append_expanded_string(yytext);
167 	[^$'"\\\n]+	{
168 		append_string(yytext, yyleng);
169 	}
170 	\\.?	{
171 		append_string(yytext + 1, yyleng - 1);
172 	}
173 	\'|\"	{
174 		if (str == yytext[0]) {
175 			BEGIN(INITIAL);
176 			yylval.string = text;
177 			return T_WORD_QUOTE;
178 		} else
179 			append_string(yytext, 1);
180 	}
181 	\n	{
182 		fprintf(stderr,
183 			"%s:%d:warning: multi-line strings not supported\n",
184 			zconf_curname(), zconf_lineno());
185 		unput('\n');
186 		BEGIN(INITIAL);
187 		yylval.string = text;
188 		return T_WORD_QUOTE;
189 	}
190 	<<EOF>>	{
191 		BEGIN(INITIAL);
192 		yylval.string = text;
193 		return T_WORD_QUOTE;
194 	}
195 }
196 
197 <HELP>{
198 	[ \t]+	{
199 		ts = 0;
200 		for (i = 0; i < yyleng; i++) {
201 			if (yytext[i] == '\t')
202 				ts = (ts & ~7) + 8;
203 			else
204 				ts++;
205 		}
206 		last_ts = ts;
207 		if (first_ts) {
208 			if (ts < first_ts) {
209 				zconf_endhelp();
210 				return T_HELPTEXT;
211 			}
212 			ts -= first_ts;
213 			while (ts > 8) {
214 				append_string("        ", 8);
215 				ts -= 8;
216 			}
217 			append_string("        ", ts);
218 		}
219 	}
220 	[ \t]*\n/[^ \t\n] {
221 		zconf_endhelp();
222 		return T_HELPTEXT;
223 	}
224 	[ \t]*\n	{
225 		append_string("\n", 1);
226 	}
227 	[^ \t\n].* {
228 		while (yyleng) {
229 			if ((yytext[yyleng-1] != ' ') && (yytext[yyleng-1] != '\t'))
230 				break;
231 			yyleng--;
232 		}
233 		append_string(yytext, yyleng);
234 		if (!first_ts)
235 			first_ts = last_ts;
236 	}
237 	<<EOF>>	{
238 		zconf_endhelp();
239 		return T_HELPTEXT;
240 	}
241 }
242 
243 <<EOF>>	{
244 	BEGIN(INITIAL);
245 
246 	if (prev_token != T_EOL && prev_token != T_HELPTEXT)
247 		fprintf(stderr, "%s:%d:warning: no new line at end of file\n",
248 			current_file->name, yylineno);
249 
250 	if (current_file) {
251 		zconf_endfile();
252 		return T_EOL;
253 	}
254 	fclose(yyin);
255 	yyterminate();
256 }
257 
258 %%
259 
260 /* second stage lexer */
261 int yylex(void)
262 {
263 	int token;
264 
265 repeat:
266 	token = yylex1();
267 
268 	if (prev_token == T_EOL || prev_token == T_HELPTEXT) {
269 		if (token == T_EOL) {
270 			/* Do not pass unneeded T_EOL to the parser. */
271 			goto repeat;
272 		} else {
273 			/*
274 			 * For the parser, update file/lineno at the first token
275 			 * of each statement. Generally, \n is a statement
276 			 * terminator in Kconfig, but it is not always true
277 			 * because \n could be escaped by a backslash.
278 			 */
279 			current_pos.file = current_file;
280 			current_pos.lineno = yylineno;
281 		}
282 	}
283 
284 	if (prev_prev_token == T_EOL && prev_token == T_WORD &&
285 	    (token == T_EQUAL || token == T_COLON_EQUAL || token == T_PLUS_EQUAL))
286 		BEGIN(ASSIGN_VAL);
287 
288 	prev_prev_token = prev_token;
289 	prev_token = token;
290 
291 	return token;
292 }
293 
294 static char *expand_token(const char *in, size_t n)
295 {
296 	char *out;
297 	int c;
298 	char c2;
299 	const char *rest, *end;
300 
301 	new_string();
302 	append_string(in, n);
303 
304 	/* get the whole line because we do not know the end of token. */
305 	while ((c = input()) != EOF) {
306 		if (c == '\n') {
307 			unput(c);
308 			break;
309 		}
310 		c2 = c;
311 		append_string(&c2, 1);
312 	}
313 
314 	rest = text;
315 	out = expand_one_token(&rest);
316 
317 	/* push back unused characters to the input stream */
318 	end = rest + strlen(rest);
319 	while (end > rest)
320 		unput(*--end);
321 
322 	free(text);
323 
324 	return out;
325 }
326 
327 static void append_expanded_string(const char *str)
328 {
329 	const char *end;
330 	char *res;
331 
332 	str++;
333 
334 	res = expand_dollar(&str);
335 
336 	/* push back unused characters to the input stream */
337 	end = str + strlen(str);
338 	while (end > str)
339 		unput(*--end);
340 
341 	append_string(res, strlen(res));
342 
343 	free(res);
344 }
345 
346 void zconf_starthelp(void)
347 {
348 	new_string();
349 	last_ts = first_ts = 0;
350 	BEGIN(HELP);
351 }
352 
353 static void zconf_endhelp(void)
354 {
355 	yylval.string = text;
356 	BEGIN(INITIAL);
357 }
358 
359 
360 /*
361  * Try to open specified file with following names:
362  * ./name
363  * $(srctree)/name
364  * The latter is used when srctree is separate from objtree
365  * when compiling the kernel.
366  * Return NULL if file is not found.
367  */
368 FILE *zconf_fopen(const char *name)
369 {
370 	char *env, fullname[PATH_MAX+1];
371 	FILE *f;
372 
373 	f = fopen(name, "r");
374 	if (!f && name != NULL && name[0] != '/') {
375 		env = getenv(SRCTREE);
376 		if (env) {
377 			snprintf(fullname, sizeof(fullname),
378 				 "%s/%s", env, name);
379 			f = fopen(fullname, "r");
380 		}
381 	}
382 	return f;
383 }
384 
385 void zconf_initscan(const char *name)
386 {
387 	yyin = zconf_fopen(name);
388 	if (!yyin) {
389 		fprintf(stderr, "can't find file %s\n", name);
390 		exit(1);
391 	}
392 
393 	current_buf = xmalloc(sizeof(*current_buf));
394 	memset(current_buf, 0, sizeof(*current_buf));
395 
396 	current_file = file_lookup(name);
397 	yylineno = 1;
398 }
399 
400 void zconf_nextfile(const char *name)
401 {
402 	struct file *iter;
403 	struct file *file = file_lookup(name);
404 	struct buffer *buf = xmalloc(sizeof(*buf));
405 	memset(buf, 0, sizeof(*buf));
406 
407 	current_buf->state = YY_CURRENT_BUFFER;
408 	yyin = zconf_fopen(file->name);
409 	if (!yyin) {
410 		fprintf(stderr, "%s:%d: can't open file \"%s\"\n",
411 			zconf_curname(), zconf_lineno(), file->name);
412 		exit(1);
413 	}
414 	yy_switch_to_buffer(yy_create_buffer(yyin, YY_BUF_SIZE));
415 	buf->parent = current_buf;
416 	current_buf = buf;
417 
418 	current_file->lineno = yylineno;
419 	file->parent = current_file;
420 
421 	for (iter = current_file; iter; iter = iter->parent) {
422 		if (!strcmp(iter->name, file->name)) {
423 			fprintf(stderr,
424 				"Recursive inclusion detected.\n"
425 				"Inclusion path:\n"
426 				"  current file : %s\n", file->name);
427 			iter = file;
428 			do {
429 				iter = iter->parent;
430 				fprintf(stderr, "  included from: %s:%d\n",
431 					iter->name, iter->lineno - 1);
432 			} while (strcmp(iter->name, file->name));
433 			exit(1);
434 		}
435 	}
436 
437 	yylineno = 1;
438 	current_file = file;
439 }
440 
441 static void zconf_endfile(void)
442 {
443 	struct buffer *parent;
444 
445 	current_file = current_file->parent;
446 	if (current_file)
447 		yylineno = current_file->lineno;
448 
449 	parent = current_buf->parent;
450 	if (parent) {
451 		fclose(yyin);
452 		yy_delete_buffer(YY_CURRENT_BUFFER);
453 		yy_switch_to_buffer(parent->state);
454 	}
455 	free(current_buf);
456 	current_buf = parent;
457 }
458 
459 int zconf_lineno(void)
460 {
461 	return current_pos.lineno;
462 }
463 
464 const char *zconf_curname(void)
465 {
466 	return current_pos.file ? current_pos.file->name : "<none>";
467 }
468