1%{
2/*
3 * Copyright © 2010 Intel Corporation
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 */
24
25#include <stdio.h>
26#include <string.h>
27#include <ctype.h>
28
29#include "glcpp.h"
30#include "glcpp-parse.h"
31
32/* Flex annoyingly generates some functions without making them
33 * static. Let's declare them here. */
34int glcpp_get_column  (yyscan_t yyscanner);
35void glcpp_set_column (int  column_no , yyscan_t yyscanner);
36
37#ifdef _MSC_VER
38#define YY_NO_UNISTD_H
39#endif
40
41#define YY_NO_INPUT
42
43#define YY_USER_ACTION							\
44	do {								\
45		if (parser->has_new_line_number)			\
46			yylineno = parser->new_line_number;		\
47		if (parser->has_new_source_number)			\
48			yylloc->source = parser->new_source_number;	\
49		yylloc->first_column = yycolumn + 1;			\
50		yylloc->first_line = yylloc->last_line = yylineno;	\
51		yycolumn += yyleng;					\
52		yylloc->last_column = yycolumn + 1;			\
53		parser->has_new_line_number = 0;			\
54		parser->has_new_source_number = 0;			\
55	} while(0);
56
57#define YY_USER_INIT			\
58	do {				\
59		yylineno = 1;		\
60		yycolumn = 0;		\
61		yylloc->source = 0;	\
62	} while(0)
63
64/* It's ugly to have macros that have return statements inside of
65 * them, but flex-based lexer generation is all built around the
66 * return statement.
67 *
68 * To mitigate the ugliness, we defer as much of the logic as possible
69 * to an actual function, not a macro (see
70 * glcpplex_update_state_per_token) and we make the word RETURN
71 * prominent in all of the macros which may return.
72 *
73 * The most-commonly-used macro is RETURN_TOKEN which will perform all
74 * necessary state updates based on the provided token,, then
75 * conditionally return the token. It will not return a token if the
76 * parser is currently skipping tokens, (such as within #if
77 * 0...#else).
78 *
79 * The RETURN_TOKEN_NEVER_SKIP macro is a lower-level variant that
80 * makes the token returning unconditional. This is needed for things
81 * like #if and the tokens of its condition, (since these must be
82 * evaluated by the parser even when otherwise skipping).
83 *
84 * Finally, RETURN_STRING_TOKEN is a simple convenience wrapper on top
85 * of RETURN_TOKEN that performs a string copy of yytext before the
86 * return.
87 */
88#define RETURN_TOKEN_NEVER_SKIP(token)					\
89	do {								\
90		if (glcpp_lex_update_state_per_token (parser, token))	\
91			return token;					\
92	} while (0)
93
94#define RETURN_TOKEN(token)						\
95	do {								\
96		if (! parser->skipping) {				\
97			RETURN_TOKEN_NEVER_SKIP(token);			\
98		}							\
99	} while(0)
100
101#define RETURN_STRING_TOKEN(token)					\
102	do {								\
103		if (! parser->skipping) {				\
104			/* We're not doing linear_strdup here, to avoid \
105			 * an implicit call on strlen() for the length  \
106			 * of the string, as this is already found by   \
107			 * flex and stored in yyleng */                 \
108			void *mem_ctx = yyextra->linalloc;		\
109			yylval->str = linear_alloc_child(mem_ctx,	\
110							 yyleng + 1);	\
111			memcpy(yylval->str, yytext, yyleng + 1);        \
112			RETURN_TOKEN_NEVER_SKIP (token);		\
113		}							\
114	} while(0)
115
116
117/* Update all state necessary for each token being returned.
118 *
119 * Here we'll be tracking newlines and spaces so that the lexer can
120 * alter its behavior as necessary, (for example, '#' has special
121 * significance if it is the first non-whitespace, non-comment token
122 * in a line, but does not otherwise).
123 *
124 * NOTE: If this function returns FALSE, then no token should be
125 * returned at all. This is used to suprress duplicate SPACE tokens.
126 */
127static int
128glcpp_lex_update_state_per_token (glcpp_parser_t *parser, int token)
129{
130	if (token != NEWLINE && token != SPACE && token != HASH_TOKEN &&
131	    !parser->lexing_version_directive) {
132		glcpp_parser_resolve_implicit_version(parser);
133	}
134
135	/* After the first non-space token in a line, we won't
136	 * allow any '#' to introduce a directive. */
137	if (token == NEWLINE) {
138		parser->first_non_space_token_this_line = 1;
139	} else if (token != SPACE) {
140		parser->first_non_space_token_this_line = 0;
141	}
142
143	/* Track newlines just to know whether a newline needs
144	 * to be inserted if end-of-file comes early. */
145	if (token == NEWLINE) {
146		parser->last_token_was_newline = 1;
147	} else {
148		parser->last_token_was_newline = 0;
149	}
150
151	/* Track spaces to avoid emitting multiple SPACE
152	 * tokens in a row. */
153	if (token == SPACE) {
154		if (! parser->last_token_was_space) {
155			parser->last_token_was_space = 1;
156			return 1;
157		} else {
158			parser->last_token_was_space = 1;
159			return 0;
160		}
161	} else {
162		parser->last_token_was_space = 0;
163		return 1;
164	}
165}
166
167
168%}
169
170%option bison-bridge bison-locations reentrant noyywrap
171%option extra-type="glcpp_parser_t *"
172%option prefix="glcpp_"
173%option stack
174%option never-interactive
175%option warn nodefault
176
177	/* Note: When adding any start conditions to this list, you must also
178	 * update the "Internal compiler error" catch-all rule near the end of
179	 * this file. */
180
181%x COMMENT DEFINE DONE HASH NEWLINE_CATCHUP UNREACHABLE
182
183SPACE		[[:space:]]
184NONSPACE	[^[:space:]]
185HSPACE		[ \t\v\f]
186HASH		#
187NEWLINE		(\r\n|\n\r|\r|\n)
188IDENTIFIER	[_a-zA-Z][_a-zA-Z0-9]*
189PP_NUMBER	[.]?[0-9]([._a-zA-Z0-9]|[eEpP][-+])*
190PUNCTUATION	[][(){}.&*~!/%<>^|;,=+-]
191
192/* The OTHER class is simply a catch-all for things that the CPP
193parser just doesn't care about. Since flex regular expressions that
194match longer strings take priority over those matching shorter
195strings, we have to be careful to avoid OTHER matching and hiding
196something that CPP does care about. So we simply exclude all
197characters that appear in any other expressions. */
198
199OTHER		[^][_#[:space:]#a-zA-Z0-9(){}.&*~!/%<>^|;,=+-]
200
201DIGITS			[0-9][0-9]*
202DECIMAL_INTEGER		[1-9][0-9]*[uU]?
203OCTAL_INTEGER		0[0-7]*[uU]?
204HEXADECIMAL_INTEGER	0[xX][0-9a-fA-F]+[uU]?
205
206%%
207
208	glcpp_parser_t *parser = yyextra;
209
210	/* When we lex a multi-line comment, we replace it (as
211	 * specified) with a single space. But if the comment spanned
212	 * multiple lines, then subsequent parsing stages will not
213	 * count correct line numbers. To avoid this problem we keep
214	 * track of all newlines that were commented out by a
215	 * multi-line comment, and we emit a NEWLINE token for each at
216	 * the next legal opportunity, (which is when the lexer would
217	 * be emitting a NEWLINE token anyway).
218	 */
219	if (YY_START == NEWLINE_CATCHUP) {
220		if (parser->commented_newlines)
221			parser->commented_newlines--;
222		if (parser->commented_newlines == 0)
223			BEGIN INITIAL;
224		RETURN_TOKEN_NEVER_SKIP (NEWLINE);
225	}
226
227	/* Set up the parser->skipping bit here before doing any lexing.
228	 *
229	 * This bit controls whether tokens are skipped, (as implemented by
230         * RETURN_TOKEN), such as between "#if 0" and "#endif".
231	 *
232	 * The parser maintains a skip_stack indicating whether we should be
233         * skipping, (and nested levels of #if/#ifdef/#ifndef/#endif) will
234         * push and pop items from the stack.
235	 *
236	 * Here are the rules for determining whether we are skipping:
237	 *
238	 *	1. If the skip stack is NULL, we are outside of all #if blocks
239	 *         and we are not skipping.
240	 *
241	 *	2. If the skip stack is non-NULL, the type of the top node in
242	 *	   the stack determines whether to skip. A type of
243	 *	   SKIP_NO_SKIP is used for blocks wheere we are emitting
244	 *	   tokens, (such as between #if 1 and #endif, or after the
245	 *	   #else of an #if 0, etc.).
246	 *
247	 *	3. The lexing_directive bit overrides the skip stack. This bit
248	 *	   is set when we are actively lexing the expression for a
249	 *	   pre-processor condition, (such as #if, #elif, or #else). In
250	 *	   this case, even if otherwise skipping, we need to emit the
251	 *	   tokens for this condition so that the parser can evaluate
252	 *	   the expression. (For, #else, there's no expression, but we
253	 *	   emit tokens so the parser can generate a nice error message
254	 *	   if there are any tokens here).
255	 */
256	if (parser->skip_stack &&
257	    parser->skip_stack->type != SKIP_NO_SKIP &&
258	    ! parser->lexing_directive)
259	{
260		parser->skipping = 1;
261	} else {
262		parser->skipping = 0;
263	}
264
265	/* Single-line comments */
266<INITIAL,DEFINE,HASH>"//"[^\r\n]* {
267}
268
269	/* Multi-line comments */
270<INITIAL,DEFINE,HASH>"/*"   { yy_push_state(COMMENT, yyscanner); }
271<COMMENT>[^*\r\n]*
272<COMMENT>[^*\r\n]*{NEWLINE} { yylineno++; yycolumn = 0; parser->commented_newlines++; }
273<COMMENT>"*"+[^*/\r\n]*
274<COMMENT>"*"+[^*/\r\n]*{NEWLINE} { yylineno++; yycolumn = 0; parser->commented_newlines++; }
275<COMMENT>"*"+"/"        {
276	yy_pop_state(yyscanner);
277	/* In the <HASH> start condition, we don't want any SPACE token. */
278	if (yyextra->space_tokens && YY_START != HASH)
279		RETURN_TOKEN (SPACE);
280}
281
282{HASH} {
283
284	/* If the '#' is the first non-whitespace, non-comment token on this
285	 * line, then it introduces a directive, switch to the <HASH> start
286	 * condition.
287	 *
288	 * Otherwise, this is just punctuation, so return the HASH_TOKEN
289         * token. */
290	if (parser->first_non_space_token_this_line) {
291		BEGIN HASH;
292		yyextra->in_define = false;
293	}
294
295	RETURN_TOKEN_NEVER_SKIP (HASH_TOKEN);
296}
297
298<HASH>version{HSPACE}+ {
299	BEGIN INITIAL;
300	yyextra->space_tokens = 0;
301	yyextra->lexing_version_directive = 1;
302	RETURN_STRING_TOKEN (VERSION_TOKEN);
303}
304
305	/* Swallow empty #pragma directives, (to avoid confusing the
306	 * downstream compiler).
307	 *
308	 * Note: We use a simple regular expression for the lookahead
309	 * here. Specifically, we cannot use the complete {NEWLINE} expression
310	 * since it uses alternation and we've found that there's a flex bug
311	 * where using alternation in the lookahead portion of a pattern
312	 * triggers a buffer overrun. */
313<HASH>pragma{HSPACE}*/[\r\n] {
314	BEGIN INITIAL;
315}
316
317	/* glcpp doesn't handle #extension, #version, or #pragma directives.
318	 * Simply pass them through to the main compiler's lexer/parser. */
319<HASH>(extension|pragma)[^\r\n]* {
320	BEGIN INITIAL;
321	RETURN_STRING_TOKEN (PRAGMA);
322}
323
324<HASH>line{HSPACE}+ {
325	BEGIN INITIAL;
326	RETURN_TOKEN (LINE);
327}
328
329<HASH>{NEWLINE} {
330	BEGIN INITIAL;
331	yyextra->space_tokens = 0;
332	yylineno++;
333	yycolumn = 0;
334	RETURN_TOKEN_NEVER_SKIP (NEWLINE);
335}
336
337	/* For the pre-processor directives, we return these tokens
338	 * even when we are otherwise skipping. */
339<HASH>ifdef {
340	if (!yyextra->in_define) {
341		BEGIN INITIAL;
342		yyextra->lexing_directive = 1;
343		yyextra->space_tokens = 0;
344		RETURN_TOKEN_NEVER_SKIP (IFDEF);
345	}
346}
347
348<HASH>ifndef {
349	if (!yyextra->in_define) {
350		BEGIN INITIAL;
351		yyextra->lexing_directive = 1;
352		yyextra->space_tokens = 0;
353		RETURN_TOKEN_NEVER_SKIP (IFNDEF);
354	}
355}
356
357<HASH>if/[^_a-zA-Z0-9] {
358	if (!yyextra->in_define) {
359		BEGIN INITIAL;
360		yyextra->lexing_directive = 1;
361		yyextra->space_tokens = 0;
362		RETURN_TOKEN_NEVER_SKIP (IF);
363	}
364}
365
366<HASH>elif/[^_a-zA-Z0-9] {
367	if (!yyextra->in_define) {
368		BEGIN INITIAL;
369		yyextra->lexing_directive = 1;
370		yyextra->space_tokens = 0;
371		RETURN_TOKEN_NEVER_SKIP (ELIF);
372	}
373}
374
375<HASH>else {
376	if (!yyextra->in_define) {
377		BEGIN INITIAL;
378		yyextra->space_tokens = 0;
379		RETURN_TOKEN_NEVER_SKIP (ELSE);
380	}
381}
382
383<HASH>endif {
384	if (!yyextra->in_define) {
385		BEGIN INITIAL;
386		yyextra->space_tokens = 0;
387		RETURN_TOKEN_NEVER_SKIP (ENDIF);
388	}
389}
390
391<HASH>error[^\r\n]* {
392	BEGIN INITIAL;
393	RETURN_STRING_TOKEN (ERROR_TOKEN);
394}
395
396	/* After we see a "#define" we enter the <DEFINE> start state
397	 * for the lexer. Within <DEFINE> we are looking for the first
398	 * identifier and specifically checking whether the identifier
399	 * is followed by a '(' or not, (to lex either a
400	 * FUNC_IDENTIFIER or an OBJ_IDENITIFIER token).
401	 *
402	 * While in the <DEFINE> state we also need to explicitly
403	 * handle a few other things that may appear before the
404	 * identifier:
405	 *
406	 * 	* Comments, (handled above with the main support for
407	 * 	  comments).
408	 *
409	 *	* Whitespace (simply ignored)
410	 *
411	 *	* Anything else, (not an identifier, not a comment,
412	 *	  and not whitespace). This will generate an error.
413	 */
414<HASH>define{HSPACE}* {
415	yyextra->in_define = true;
416	if (!parser->skipping) {
417		BEGIN DEFINE;
418		yyextra->space_tokens = 0;
419		RETURN_TOKEN (DEFINE_TOKEN);
420	}
421}
422
423<HASH>undef {
424	BEGIN INITIAL;
425	yyextra->space_tokens = 0;
426	RETURN_TOKEN (UNDEF);
427}
428
429<HASH>{HSPACE}+ {
430	/* Nothing to do here. Importantly, don't leave the <HASH>
431	 * start condition, since it's legal to have space between the
432	 * '#' and the directive.. */
433}
434
435	/* This will catch any non-directive garbage after a HASH */
436<HASH>{NONSPACE} {
437	if (!parser->skipping) {
438		BEGIN INITIAL;
439		RETURN_TOKEN (GARBAGE);
440	}
441}
442
443	/* An identifier immediately followed by '(' */
444<DEFINE>{IDENTIFIER}/"(" {
445	BEGIN INITIAL;
446	RETURN_STRING_TOKEN (FUNC_IDENTIFIER);
447}
448
449	/* An identifier not immediately followed by '(' */
450<DEFINE>{IDENTIFIER} {
451	BEGIN INITIAL;
452	RETURN_STRING_TOKEN (OBJ_IDENTIFIER);
453}
454
455	/* Whitespace */
456<DEFINE>{HSPACE}+ {
457	/* Just ignore it. Nothing to do here. */
458}
459
460	/* '/' not followed by '*', so not a comment. This is an error. */
461<DEFINE>[/][^*]{NONSPACE}* {
462	BEGIN INITIAL;
463	glcpp_error(yylloc, yyextra, "#define followed by a non-identifier: %s", yytext);
464	RETURN_STRING_TOKEN (INTEGER_STRING);
465}
466
467	/* A character that can't start an identifier, comment, or
468	 * space. This is an error. */
469<DEFINE>[^_a-zA-Z/[:space:]]{NONSPACE}* {
470	BEGIN INITIAL;
471	glcpp_error(yylloc, yyextra, "#define followed by a non-identifier: %s", yytext);
472	RETURN_STRING_TOKEN (INTEGER_STRING);
473}
474
475{DECIMAL_INTEGER} {
476	RETURN_STRING_TOKEN (INTEGER_STRING);
477}
478
479{OCTAL_INTEGER} {
480	RETURN_STRING_TOKEN (INTEGER_STRING);
481}
482
483{HEXADECIMAL_INTEGER} {
484	RETURN_STRING_TOKEN (INTEGER_STRING);
485}
486
487"<<"  {
488	RETURN_TOKEN (LEFT_SHIFT);
489}
490
491">>" {
492	RETURN_TOKEN (RIGHT_SHIFT);
493}
494
495"<=" {
496	RETURN_TOKEN (LESS_OR_EQUAL);
497}
498
499">=" {
500	RETURN_TOKEN (GREATER_OR_EQUAL);
501}
502
503"==" {
504	RETURN_TOKEN (EQUAL);
505}
506
507"!=" {
508	RETURN_TOKEN (NOT_EQUAL);
509}
510
511"&&" {
512	RETURN_TOKEN (AND);
513}
514
515"||" {
516	RETURN_TOKEN (OR);
517}
518
519"++" {
520	RETURN_TOKEN (PLUS_PLUS);
521}
522
523"--" {
524	RETURN_TOKEN (MINUS_MINUS);
525}
526
527"##" {
528	if (! parser->skipping) {
529		if (parser->is_gles)
530			glcpp_error(yylloc, yyextra, "Token pasting (##) is illegal in GLES");
531		RETURN_TOKEN (PASTE);
532	}
533}
534
535"defined" {
536	RETURN_TOKEN (DEFINED);
537}
538
539{IDENTIFIER} {
540	RETURN_STRING_TOKEN (IDENTIFIER);
541}
542
543{PP_NUMBER} {
544	RETURN_STRING_TOKEN (OTHER);
545}
546
547{PUNCTUATION} {
548	RETURN_TOKEN (yytext[0]);
549}
550
551{OTHER}+ {
552	RETURN_STRING_TOKEN (OTHER);
553}
554
555{HSPACE} {
556	if (yyextra->space_tokens) {
557		RETURN_TOKEN (SPACE);
558	}
559}
560
561	/* We preserve all newlines, even between #if 0..#endif, so no
562	skipping.. */
563<*>{NEWLINE} {
564	if (parser->commented_newlines) {
565		BEGIN NEWLINE_CATCHUP;
566	} else {
567		BEGIN INITIAL;
568	}
569	yyextra->space_tokens = 1;
570	yyextra->lexing_directive = 0;
571	yyextra->lexing_version_directive = 0;
572	yylineno++;
573	yycolumn = 0;
574	RETURN_TOKEN_NEVER_SKIP (NEWLINE);
575}
576
577<INITIAL,COMMENT,DEFINE,HASH><<EOF>> {
578	if (YY_START == COMMENT)
579		glcpp_error(yylloc, yyextra, "Unterminated comment");
580	BEGIN DONE; /* Don't keep matching this rule forever. */
581	yyextra->lexing_directive = 0;
582	yyextra->lexing_version_directive = 0;
583	if (! parser->last_token_was_newline)
584		RETURN_TOKEN (NEWLINE);
585}
586
587	/* This is a catch-all to avoid the annoying default flex action which
588	 * matches any character and prints it. If any input ever matches this
589	 * rule, then we have made a mistake above and need to fix one or more
590	 * of the preceding patterns to match that input. */
591
592<*>. {
593	glcpp_error(yylloc, yyextra, "Internal compiler error: Unexpected character: %s", yytext);
594
595	/* We don't actually use the UNREACHABLE start condition. We
596	only have this block here so that we can pretend to call some
597	generated functions, (to avoid "defined but not used"
598	warnings. */
599        if (YY_START == UNREACHABLE) {
600		unput('.');
601		yy_top_state(yyextra);
602	}
603}
604
605%%
606
607void
608glcpp_lex_set_source_string(glcpp_parser_t *parser, const char *shader)
609{
610	yy_scan_string(shader, parser->scanner);
611}
612