xref: /linux/scripts/kconfig/lexer.l (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 <xalloc.h>
17 #include "lkc.h"
18 #include "preprocess.h"
19 
20 #include "parser.tab.h"
21 
22 #define YY_DECL		static int yylex1(void)
23 
24 #define START_STRSIZE	16
25 
26 /* The Kconfig file currently being parsed.  */
27 const char *cur_filename;
28 
29 /*
30  * The line number of the current statement. This does not match yylineno.
31  * yylineno is used by the lexer, while cur_lineno is used by the parser.
32  */
33 int cur_lineno;
34 
35 static int prev_prev_token = T_EOL;
36 static int prev_token = T_EOL;
37 static char *text;
38 static int text_size, text_asize;
39 
40 struct buffer {
41 	struct buffer *parent;
42 	YY_BUFFER_STATE state;
43 	int yylineno;
44 	const char *filename;
45 	int source_lineno;
46 };
47 
48 static struct buffer *current_buf;
49 
50 static int last_ts, first_ts;
51 
52 static char *expand_token(const char *in, size_t n);
53 static void append_expanded_string(const char *in);
54 static void zconf_endhelp(void);
55 static void zconf_endfile(void);
56 
57 static void new_string(void)
58 {
59 	text = xmalloc(START_STRSIZE);
60 	text_asize = START_STRSIZE;
61 	text_size = 0;
62 	*text = 0;
63 }
64 
65 static void append_string(const char *str, int size)
66 {
67 	int new_size = text_size + size + 1;
68 	if (new_size > text_asize) {
69 		new_size += START_STRSIZE - 1;
70 		new_size &= -START_STRSIZE;
71 		text = xrealloc(text, new_size);
72 		text_asize = new_size;
73 	}
74 	memcpy(text + text_size, str, size);
75 	text_size += size;
76 	text[text_size] = 0;
77 }
78 
79 static void alloc_string(const char *str, int size)
80 {
81 	text = xmalloc(size + 1);
82 	memcpy(text, str, size);
83 	text[size] = 0;
84 }
85 
86 static void warn_ignored_character(char chr)
87 {
88 	fprintf(stderr,
89 	        "%s:%d:warning: ignoring unsupported character '%c'\n",
90 	        cur_filename, yylineno, chr);
91 }
92 %}
93 
94 n	[A-Za-z0-9_-]
95 
96 %%
97 	char open_quote = 0;
98 
99 #.*			/* ignore comment */
100 [ \t]*			/* whitespaces */
101 \\\n			/* escaped new line */
102 \n			return T_EOL;
103 "bool"			return T_BOOL;
104 "choice"		return T_CHOICE;
105 "comment"		return T_COMMENT;
106 "config"		return T_CONFIG;
107 "def_bool"		return T_DEF_BOOL;
108 "def_tristate"		return T_DEF_TRISTATE;
109 "default"		return T_DEFAULT;
110 "depends"		return T_DEPENDS;
111 "endchoice"		return T_ENDCHOICE;
112 "endif"			return T_ENDIF;
113 "endmenu"		return T_ENDMENU;
114 "help"			return T_HELP;
115 "hex"			return T_HEX;
116 "if"			return T_IF;
117 "imply"			return T_IMPLY;
118 "int"			return T_INT;
119 "mainmenu"		return T_MAINMENU;
120 "menu"			return T_MENU;
121 "menuconfig"		return T_MENUCONFIG;
122 "modules"		return T_MODULES;
123 "on"			return T_ON;
124 "prompt"		return T_PROMPT;
125 "range"			return T_RANGE;
126 "select"		return T_SELECT;
127 "source"		return T_SOURCE;
128 "string"		return T_STRING;
129 "tristate"		return T_TRISTATE;
130 "visible"		return T_VISIBLE;
131 "||"			return T_OR;
132 "&&"			return T_AND;
133 "="			return T_EQUAL;
134 "!="			return T_UNEQUAL;
135 "<"			return T_LESS;
136 "<="			return T_LESS_EQUAL;
137 ">"			return T_GREATER;
138 ">="			return T_GREATER_EQUAL;
139 "!"			return T_NOT;
140 "("			return T_OPEN_PAREN;
141 ")"			return T_CLOSE_PAREN;
142 ":="			return T_COLON_EQUAL;
143 "+="			return T_PLUS_EQUAL;
144 \"|\'			{
145 				open_quote = yytext[0];
146 				new_string();
147 				BEGIN(STRING);
148 			}
149 {n}+			{
150 				alloc_string(yytext, yyleng);
151 				yylval.string = text;
152 				return T_WORD;
153 			}
154 ({n}|$)+		{
155 				/* this token includes at least one '$' */
156 				yylval.string = expand_token(yytext, yyleng);
157 				if (strlen(yylval.string))
158 					return T_WORD;
159 				free(yylval.string);
160 			}
161 .			warn_ignored_character(*yytext);
162 
163 <ASSIGN_VAL>{
164 	[^[:blank:]\n]+.*	{
165 		alloc_string(yytext, yyleng);
166 		yylval.string = text;
167 		return T_ASSIGN_VAL;
168 	}
169 	\n	{ BEGIN(INITIAL); return T_EOL; }
170 	.
171 }
172 
173 <STRING>{
174 	"$".*	append_expanded_string(yytext);
175 	[^$'"\\\n]+	{
176 		append_string(yytext, yyleng);
177 	}
178 	\\.?	{
179 		append_string(yytext + 1, yyleng - 1);
180 	}
181 	\'|\"	{
182 		if (open_quote == yytext[0]) {
183 			BEGIN(INITIAL);
184 			yylval.string = text;
185 			return T_WORD_QUOTE;
186 		} else
187 			append_string(yytext, 1);
188 	}
189 	\n	{
190 		fprintf(stderr,
191 			"%s:%d:warning: multi-line strings not supported\n",
192 			cur_filename, cur_lineno);
193 		unput('\n');
194 		BEGIN(INITIAL);
195 		yylval.string = text;
196 		return T_WORD_QUOTE;
197 	}
198 	<<EOF>>	{
199 		BEGIN(INITIAL);
200 		yylval.string = text;
201 		return T_WORD_QUOTE;
202 	}
203 }
204 
205 <HELP>{
206 	[ \t]+	{
207 		int ts, i;
208 
209 		ts = 0;
210 		for (i = 0; i < yyleng; i++) {
211 			if (yytext[i] == '\t')
212 				ts = (ts & ~7) + 8;
213 			else
214 				ts++;
215 		}
216 		last_ts = ts;
217 		if (first_ts) {
218 			if (ts < first_ts) {
219 				zconf_endhelp();
220 				return T_HELPTEXT;
221 			}
222 			ts -= first_ts;
223 			while (ts > 8) {
224 				append_string("        ", 8);
225 				ts -= 8;
226 			}
227 			append_string("        ", ts);
228 		}
229 	}
230 	[ \t]*\n/[^ \t\n] {
231 		zconf_endhelp();
232 		return T_HELPTEXT;
233 	}
234 	[ \t]*\n	{
235 		append_string("\n", 1);
236 	}
237 	[^ \t\n].* {
238 		while (yyleng) {
239 			if ((yytext[yyleng-1] != ' ') && (yytext[yyleng-1] != '\t'))
240 				break;
241 			yyleng--;
242 		}
243 		append_string(yytext, yyleng);
244 		if (!first_ts)
245 			first_ts = last_ts;
246 	}
247 	<<EOF>>	{
248 		zconf_endhelp();
249 		return T_HELPTEXT;
250 	}
251 }
252 
253 <<EOF>>	{
254 	BEGIN(INITIAL);
255 
256 	if (prev_token != T_EOL && prev_token != T_HELPTEXT)
257 		fprintf(stderr, "%s:%d:warning: no new line at end of file\n",
258 			cur_filename, yylineno);
259 
260 	if (current_buf) {
261 		zconf_endfile();
262 		return T_EOL;
263 	}
264 	fclose(yyin);
265 	yyterminate();
266 }
267 
268 %%
269 
270 /* second stage lexer */
271 int yylex(void)
272 {
273 	int token;
274 
275 repeat:
276 	token = yylex1();
277 
278 	if (prev_token == T_EOL || prev_token == T_HELPTEXT) {
279 		if (token == T_EOL)
280 			/* Do not pass unneeded T_EOL to the parser. */
281 			goto repeat;
282 		else
283 			/*
284 			 * For the parser, update lineno at the first token
285 			 * of each statement. Generally, \n is a statement
286 			 * terminator in Kconfig, but it is not always true
287 			 * because \n could be escaped by a backslash.
288 			 */
289 			cur_lineno = yylineno;
290 	}
291 
292 	if (prev_prev_token == T_EOL && prev_token == T_WORD &&
293 	    (token == T_EQUAL || token == T_COLON_EQUAL || token == T_PLUS_EQUAL))
294 		BEGIN(ASSIGN_VAL);
295 
296 	prev_prev_token = prev_token;
297 	prev_token = token;
298 
299 	return token;
300 }
301 
302 static char *expand_token(const char *in, size_t n)
303 {
304 	char *out;
305 	int c;
306 	char c2;
307 	const char *rest, *end;
308 
309 	new_string();
310 	append_string(in, n);
311 
312 	/*
313 	 * get the whole line because we do not know the end of token.
314 	 * input() returns 0 (not EOF!) when it reachs the end of file.
315 	 */
316 	while ((c = input()) != 0) {
317 		if (c == '\n') {
318 			unput(c);
319 			break;
320 		}
321 		c2 = c;
322 		append_string(&c2, 1);
323 	}
324 
325 	rest = text;
326 	out = expand_one_token(&rest);
327 
328 	/* push back unused characters to the input stream */
329 	end = rest + strlen(rest);
330 	while (end > rest)
331 		unput(*--end);
332 
333 	free(text);
334 
335 	return out;
336 }
337 
338 static void append_expanded_string(const char *str)
339 {
340 	const char *end;
341 	char *res;
342 
343 	str++;
344 
345 	res = expand_dollar(&str);
346 
347 	/* push back unused characters to the input stream */
348 	end = str + strlen(str);
349 	while (end > str)
350 		unput(*--end);
351 
352 	append_string(res, strlen(res));
353 
354 	free(res);
355 }
356 
357 void zconf_starthelp(void)
358 {
359 	new_string();
360 	last_ts = first_ts = 0;
361 	BEGIN(HELP);
362 }
363 
364 static void zconf_endhelp(void)
365 {
366 	yylval.string = text;
367 	BEGIN(INITIAL);
368 }
369 
370 
371 /*
372  * Try to open specified file with following names:
373  * ./name
374  * $(srctree)/name
375  * The latter is used when srctree is separate from objtree
376  * when compiling the kernel.
377  * Return NULL if file is not found.
378  */
379 FILE *zconf_fopen(const char *name)
380 {
381 	char *env, fullname[PATH_MAX+1];
382 	FILE *f;
383 
384 	f = fopen(name, "r");
385 	if (!f && name != NULL && name[0] != '/') {
386 		env = getenv(SRCTREE);
387 		if (env) {
388 			snprintf(fullname, sizeof(fullname),
389 				 "%s/%s", env, name);
390 			f = fopen(fullname, "r");
391 		}
392 	}
393 	return f;
394 }
395 
396 void zconf_initscan(const char *name)
397 {
398 	yyin = zconf_fopen(name);
399 	if (!yyin) {
400 		fprintf(stderr, "can't find file %s\n", name);
401 		exit(1);
402 	}
403 
404 	cur_filename = file_lookup(name);
405 	yylineno = 1;
406 }
407 
408 void zconf_nextfile(const char *name)
409 {
410 	struct buffer *buf = xmalloc(sizeof(*buf));
411 	bool recur_include = false;
412 
413 	buf->state = YY_CURRENT_BUFFER;
414 	buf->yylineno = yylineno;
415 	buf->filename = cur_filename;
416 	buf->source_lineno = cur_lineno;
417 	buf->parent = current_buf;
418 	current_buf = buf;
419 	yyin = zconf_fopen(name);
420 	if (!yyin) {
421 		fprintf(stderr, "%s:%d: can't open file \"%s\"\n",
422 			cur_filename, cur_lineno, name);
423 		exit(1);
424 	}
425 	yy_switch_to_buffer(yy_create_buffer(yyin, YY_BUF_SIZE));
426 
427 	for (buf = current_buf; buf; buf = buf->parent) {
428 		if (!strcmp(buf->filename, name))
429 			recur_include = true;
430 	}
431 
432 	if (recur_include) {
433 		fprintf(stderr,
434 			"Recursive inclusion detected.\n"
435 			"Inclusion path:\n"
436 			"  current file : %s\n", name);
437 
438 		for (buf = current_buf; buf; buf = buf->parent)
439 			fprintf(stderr, "  included from: %s:%d\n",
440 				buf->filename, buf->source_lineno);
441 		exit(1);
442 	}
443 
444 	yylineno = 1;
445 	cur_filename = file_lookup(name);
446 }
447 
448 static void zconf_endfile(void)
449 {
450 	struct buffer *tmp;
451 
452 	fclose(yyin);
453 	yy_delete_buffer(YY_CURRENT_BUFFER);
454 	yy_switch_to_buffer(current_buf->state);
455 	yylineno = current_buf->yylineno;
456 	cur_filename = current_buf->filename;
457 	tmp = current_buf;
458 	current_buf = current_buf->parent;
459 	free(tmp);
460 }
461