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 "preprocess.h"
18
19#include "parser.tab.h"
20
21#define YY_DECL		static int yylex1(void)
22
23#define START_STRSIZE	16
24
25/* The Kconfig file currently being parsed.  */
26const char *cur_filename;
27
28/*
29 * The line number of the current statement. This does not match yylineno.
30 * yylineno is used by the lexer, while cur_lineno is used by the parser.
31 */
32int cur_lineno;
33
34static int prev_prev_token = T_EOL;
35static int prev_token = T_EOL;
36static char *text;
37static int text_size, text_asize;
38
39struct buffer {
40	struct buffer *parent;
41	YY_BUFFER_STATE state;
42	int yylineno;
43	const char *filename;
44	int source_lineno;
45};
46
47static struct buffer *current_buf;
48
49static int last_ts, first_ts;
50
51static char *expand_token(const char *in, size_t n);
52static void append_expanded_string(const char *in);
53static void zconf_endhelp(void);
54static void zconf_endfile(void);
55
56static void new_string(void)
57{
58	text = xmalloc(START_STRSIZE);
59	text_asize = START_STRSIZE;
60	text_size = 0;
61	*text = 0;
62}
63
64static void append_string(const char *str, int size)
65{
66	int new_size = text_size + size + 1;
67	if (new_size > text_asize) {
68		new_size += START_STRSIZE - 1;
69		new_size &= -START_STRSIZE;
70		text = xrealloc(text, new_size);
71		text_asize = new_size;
72	}
73	memcpy(text + text_size, str, size);
74	text_size += size;
75	text[text_size] = 0;
76}
77
78static void alloc_string(const char *str, int size)
79{
80	text = xmalloc(size + 1);
81	memcpy(text, str, size);
82	text[size] = 0;
83}
84
85static void warn_ignored_character(char chr)
86{
87	fprintf(stderr,
88	        "%s:%d:warning: ignoring unsupported character '%c'\n",
89	        cur_filename, yylineno, chr);
90}
91%}
92
93n	[A-Za-z0-9_-]
94
95%%
96	char open_quote = 0;
97
98#.*			/* ignore comment */
99[ \t]*			/* whitespaces */
100\\\n			/* escaped new line */
101\n			return T_EOL;
102"bool"			return T_BOOL;
103"choice"		return T_CHOICE;
104"comment"		return T_COMMENT;
105"config"		return T_CONFIG;
106"def_bool"		return T_DEF_BOOL;
107"def_tristate"		return T_DEF_TRISTATE;
108"default"		return T_DEFAULT;
109"depends"		return T_DEPENDS;
110"endchoice"		return T_ENDCHOICE;
111"endif"			return T_ENDIF;
112"endmenu"		return T_ENDMENU;
113"help"			return T_HELP;
114"hex"			return T_HEX;
115"if"			return T_IF;
116"imply"			return T_IMPLY;
117"int"			return T_INT;
118"mainmenu"		return T_MAINMENU;
119"menu"			return T_MENU;
120"menuconfig"		return T_MENUCONFIG;
121"modules"		return T_MODULES;
122"on"			return T_ON;
123"optional"		return T_OPTIONAL;
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 */
271int yylex(void)
272{
273	int token;
274
275repeat:
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
302static 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
338static 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
357void zconf_starthelp(void)
358{
359	new_string();
360	last_ts = first_ts = 0;
361	BEGIN(HELP);
362}
363
364static 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 */
379FILE *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
396void 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
408void 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
448static 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