xref: /linux/scripts/kconfig/lexer.l (revision a5ba183bdeeeedd5f5b683c02561072848258496)
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 
new_string(void)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 
append_string(const char * str,int size)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 
alloc_string(const char * str,int size)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 
warn_ignored_character(char chr)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 "transitional"		return T_TRANSITIONAL;
130 "tristate"		return T_TRISTATE;
131 "visible"		return T_VISIBLE;
132 "||"			return T_OR;
133 "&&"			return T_AND;
134 "="			return T_EQUAL;
135 "!="			return T_UNEQUAL;
136 "<"			return T_LESS;
137 "<="			return T_LESS_EQUAL;
138 ">"			return T_GREATER;
139 ">="			return T_GREATER_EQUAL;
140 "!"			return T_NOT;
141 "("			return T_OPEN_PAREN;
142 ")"			return T_CLOSE_PAREN;
143 ":="			return T_COLON_EQUAL;
144 "+="			return T_PLUS_EQUAL;
145 \"|\'			{
146 				open_quote = yytext[0];
147 				new_string();
148 				BEGIN(STRING);
149 			}
150 {n}+			{
151 				alloc_string(yytext, yyleng);
152 				yylval.string = text;
153 				return T_WORD;
154 			}
155 ({n}|$)+		{
156 				/* this token includes at least one '$' */
157 				yylval.string = expand_token(yytext, yyleng);
158 				if (strlen(yylval.string))
159 					return T_WORD;
160 				free(yylval.string);
161 			}
162 .			warn_ignored_character(*yytext);
163 
164 <ASSIGN_VAL>{
165 	[^[:blank:]\n]+.*	{
166 		alloc_string(yytext, yyleng);
167 		yylval.string = text;
168 		return T_ASSIGN_VAL;
169 	}
170 	\n	{ BEGIN(INITIAL); return T_EOL; }
171 	.
172 }
173 
174 <STRING>{
175 	"$".*	append_expanded_string(yytext);
176 	[^$'"\\\n]+	{
177 		append_string(yytext, yyleng);
178 	}
179 	\\.?	{
180 		append_string(yytext + 1, yyleng - 1);
181 	}
182 	\'|\"	{
183 		if (open_quote == yytext[0]) {
184 			BEGIN(INITIAL);
185 			yylval.string = text;
186 			return T_WORD_QUOTE;
187 		} else
188 			append_string(yytext, 1);
189 	}
190 	\n	{
191 		fprintf(stderr,
192 			"%s:%d:warning: multi-line strings not supported\n",
193 			cur_filename, cur_lineno);
194 		unput('\n');
195 		BEGIN(INITIAL);
196 		yylval.string = text;
197 		return T_WORD_QUOTE;
198 	}
199 	<<EOF>>	{
200 		BEGIN(INITIAL);
201 		yylval.string = text;
202 		return T_WORD_QUOTE;
203 	}
204 }
205 
206 <HELP>{
207 	[ \t]+	{
208 		int ts, i;
209 
210 		ts = 0;
211 		for (i = 0; i < yyleng; i++) {
212 			if (yytext[i] == '\t')
213 				ts = (ts & ~7) + 8;
214 			else
215 				ts++;
216 		}
217 		last_ts = ts;
218 		if (first_ts) {
219 			if (ts < first_ts) {
220 				zconf_endhelp();
221 				return T_HELPTEXT;
222 			}
223 			ts -= first_ts;
224 			while (ts > 8) {
225 				append_string("        ", 8);
226 				ts -= 8;
227 			}
228 			append_string("        ", ts);
229 		}
230 	}
231 	[ \t]*\n/[^ \t\n] {
232 		zconf_endhelp();
233 		return T_HELPTEXT;
234 	}
235 	[ \t]*\n	{
236 		append_string("\n", 1);
237 	}
238 	[^ \t\n].* {
239 		while (yyleng) {
240 			if ((yytext[yyleng-1] != ' ') && (yytext[yyleng-1] != '\t'))
241 				break;
242 			yyleng--;
243 		}
244 		append_string(yytext, yyleng);
245 		if (!first_ts)
246 			first_ts = last_ts;
247 	}
248 	<<EOF>>	{
249 		zconf_endhelp();
250 		return T_HELPTEXT;
251 	}
252 }
253 
254 <<EOF>>	{
255 	BEGIN(INITIAL);
256 
257 	if (prev_token != T_EOL && prev_token != T_HELPTEXT)
258 		fprintf(stderr, "%s:%d:warning: no new line at end of file\n",
259 			cur_filename, yylineno);
260 
261 	if (current_buf) {
262 		zconf_endfile();
263 		return T_EOL;
264 	}
265 	fclose(yyin);
266 	yyterminate();
267 }
268 
269 %%
270 
271 /* second stage lexer */
272 int yylex(void)
273 {
274 	int token;
275 
276 repeat:
277 	token = yylex1();
278 
279 	if (prev_token == T_EOL || prev_token == T_HELPTEXT) {
280 		if (token == T_EOL)
281 			/* Do not pass unneeded T_EOL to the parser. */
282 			goto repeat;
283 		else
284 			/*
285 			 * For the parser, update lineno at the first token
286 			 * of each statement. Generally, \n is a statement
287 			 * terminator in Kconfig, but it is not always true
288 			 * because \n could be escaped by a backslash.
289 			 */
290 			cur_lineno = yylineno;
291 	}
292 
293 	if (prev_prev_token == T_EOL && prev_token == T_WORD &&
294 	    (token == T_EQUAL || token == T_COLON_EQUAL || token == T_PLUS_EQUAL))
295 		BEGIN(ASSIGN_VAL);
296 
297 	prev_prev_token = prev_token;
298 	prev_token = token;
299 
300 	return token;
301 }
302 
303 static char *expand_token(const char *in, size_t n)
304 {
305 	char *out;
306 	int c;
307 	char c2;
308 	const char *rest, *end;
309 
310 	new_string();
311 	append_string(in, n);
312 
313 	/*
314 	 * get the whole line because we do not know the end of token.
315 	 * input() returns 0 (not EOF!) when it reachs the end of file.
316 	 */
317 	while ((c = input()) != 0) {
318 		if (c == '\n') {
319 			unput(c);
320 			break;
321 		}
322 		c2 = c;
323 		append_string(&c2, 1);
324 	}
325 
326 	rest = text;
327 	out = expand_one_token(&rest);
328 
329 	/* push back unused characters to the input stream */
330 	end = rest + strlen(rest);
331 	while (end > rest)
332 		unput(*--end);
333 
334 	free(text);
335 
336 	return out;
337 }
338 
339 static void append_expanded_string(const char *str)
340 {
341 	const char *end;
342 	char *res;
343 
344 	str++;
345 
346 	res = expand_dollar(&str);
347 
348 	/* push back unused characters to the input stream */
349 	end = str + strlen(str);
350 	while (end > str)
351 		unput(*--end);
352 
353 	append_string(res, strlen(res));
354 
355 	free(res);
356 }
357 
358 void zconf_starthelp(void)
359 {
360 	new_string();
361 	last_ts = first_ts = 0;
362 	BEGIN(HELP);
363 }
364 
365 static void zconf_endhelp(void)
366 {
367 	yylval.string = text;
368 	BEGIN(INITIAL);
369 }
370 
371 
372 /*
373  * Try to open specified file with following names:
374  * ./name
375  * $(srctree)/name
376  * The latter is used when srctree is separate from objtree
377  * when compiling the kernel.
378  * Return NULL if file is not found.
379  */
380 FILE *zconf_fopen(const char *name)
381 {
382 	char *env, fullname[PATH_MAX+1];
383 	FILE *f;
384 
385 	f = fopen(name, "r");
386 	if (!f && name != NULL && name[0] != '/') {
387 		env = getenv(SRCTREE);
388 		if (env) {
389 			snprintf(fullname, sizeof(fullname),
390 				 "%s/%s", env, name);
391 			f = fopen(fullname, "r");
392 		}
393 	}
394 	return f;
395 }
396 
397 void zconf_initscan(const char *name)
398 {
399 	yyin = zconf_fopen(name);
400 	if (!yyin) {
401 		fprintf(stderr, "can't find file %s\n", name);
402 		exit(1);
403 	}
404 
405 	cur_filename = file_lookup(name);
406 	yylineno = 1;
407 }
408 
409 void zconf_nextfile(const char *name)
410 {
411 	struct buffer *buf = xmalloc(sizeof(*buf));
412 	bool recur_include = false;
413 
414 	buf->state = YY_CURRENT_BUFFER;
415 	buf->yylineno = yylineno;
416 	buf->filename = cur_filename;
417 	buf->source_lineno = cur_lineno;
418 	buf->parent = current_buf;
419 	current_buf = buf;
420 	yyin = zconf_fopen(name);
421 	if (!yyin) {
422 		fprintf(stderr, "%s:%d: can't open file \"%s\"\n",
423 			cur_filename, cur_lineno, name);
424 		exit(1);
425 	}
426 	yy_switch_to_buffer(yy_create_buffer(yyin, YY_BUF_SIZE));
427 
428 	for (buf = current_buf; buf; buf = buf->parent) {
429 		if (!strcmp(buf->filename, name))
430 			recur_include = true;
431 	}
432 
433 	if (recur_include) {
434 		fprintf(stderr,
435 			"Recursive inclusion detected.\n"
436 			"Inclusion path:\n"
437 			"  current file : %s\n", name);
438 
439 		for (buf = current_buf; buf; buf = buf->parent)
440 			fprintf(stderr, "  included from: %s:%d\n",
441 				buf->filename, buf->source_lineno);
442 		exit(1);
443 	}
444 
445 	yylineno = 1;
446 	cur_filename = file_lookup(name);
447 }
448 
449 static void zconf_endfile(void)
450 {
451 	struct buffer *tmp;
452 
453 	fclose(yyin);
454 	yy_delete_buffer(YY_CURRENT_BUFFER);
455 	yy_switch_to_buffer(current_buf->state);
456 	yylineno = current_buf->yylineno;
457 	cur_filename = current_buf->filename;
458 	tmp = current_buf;
459 	current_buf = current_buf->parent;
460 	free(tmp);
461 }
462