xref: /freebsd/cddl/contrib/opensolaris/lib/libdtrace/common/dt_lex.l (revision 7aa383846770374466b1dcb2cefd71bde9acf463)
1 %{
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  *
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <string.h>
29 #include <stdlib.h>
30 #include <stdio.h>
31 #include <assert.h>
32 #include <ctype.h>
33 #include <errno.h>
34 
35 #include <dt_impl.h>
36 #include <dt_grammar.h>
37 #include <dt_parser.h>
38 #include <dt_string.h>
39 
40 /*
41  * We need to undefine lex's input and unput macros so that references to these
42  * call the functions provided at the end of this source file.
43  */
44 #if defined(sun)
45 #undef input
46 #undef unput
47 #else
48 /*
49  * Define YY_INPUT for flex since input() can't be re-defined.
50  */
51 #define YY_INPUT(buf,result,max_size) \
52 	if (yypcb->pcb_fileptr != NULL) { \
53 		if (((result = fread(buf, 1, max_size, yypcb->pcb_fileptr)) == 0) \
54 		    && ferror(yypcb->pcb_fileptr)) \
55 			longjmp(yypcb->pcb_jmpbuf, EDT_FIO); \
56 	} else { \
57 		int n; \
58 		for (n = 0; n < max_size && \
59 		    yypcb->pcb_strptr < yypcb->pcb_string + yypcb->pcb_strlen; n++) \
60 			buf[n] = *yypcb->pcb_strptr++; \
61 		result = n; \
62 	}
63 /*
64  * Do not EOF let tokens to be put back. This does not work with flex.
65  * On the other hand, leaving current buffer in same state it was when
66  * last EOF was received guarantees that input() will keep returning EOF
67  * for all subsequent invocations, which is the effect desired.
68  */
69 #undef  unput
70 #define unput(c)					\
71 	do {						\
72 		int _c = c;				\
73 		if (_c != EOF)				\
74 			yyunput(_c, yytext_ptr);	\
75 	} while(0)
76 #endif
77 
78 static int id_or_type(const char *);
79 #if defined(sun)
80 static int input(void);
81 static void unput(int);
82 #endif
83 
84 /*
85  * We first define a set of labeled states for use in the D lexer and then a
86  * set of regular expressions to simplify things below. The lexer states are:
87  *
88  * S0 - D program clause and expression lexing
89  * S1 - D comments (i.e. skip everything until end of comment)
90  * S2 - D program outer scope (probe specifiers and declarations)
91  * S3 - D control line parsing (i.e. after ^# is seen but before \n)
92  * S4 - D control line scan (locate control directives only and invoke S3)
93  */
94 %}
95 
96 %e 1500		/* maximum nodes */
97 %p 3700		/* maximum positions */
98 %n 600		/* maximum states */
99 
100 %s S0 S1 S2 S3 S4
101 
102 RGX_AGG		"@"[a-zA-Z_][0-9a-zA-Z_]*
103 RGX_PSPEC	[-$:a-zA-Z_.?*\\\[\]!][-$:0-9a-zA-Z_.`?*\\\[\]!]*
104 RGX_IDENT	[a-zA-Z_`][0-9a-zA-Z_`]*
105 RGX_INT		([0-9]+|0[xX][0-9A-Fa-f]+)[uU]?[lL]?[lL]?
106 RGX_FP		([0-9]+("."?)[0-9]*|"."[0-9]+)((e|E)("+"|-)?[0-9]+)?[fFlL]?
107 RGX_WS		[\f\n\r\t\v ]
108 RGX_STR		([^"\\\n]|\\[^"\n]|\\\")*
109 RGX_CHR		([^'\\\n]|\\[^'\n]|\\')*
110 RGX_INTERP	^[\f\t\v ]*#!.*
111 RGX_CTL		^[\f\t\v ]*#
112 
113 %%
114 
115 %{
116 
117 /*
118  * We insert a special prologue into yylex() itself: if the pcb contains a
119  * context token, we return that prior to running the normal lexer.  This
120  * allows libdtrace to force yacc into one of our three parsing contexts: D
121  * expression (DT_CTX_DEXPR), D program (DT_CTX_DPROG) or D type (DT_CTX_DTYPE).
122  * Once the token is returned, we clear it so this only happens once.
123  */
124 if (yypcb->pcb_token != 0) {
125 	int tok = yypcb->pcb_token;
126 	yypcb->pcb_token = 0;
127 	return (tok);
128 }
129 
130 %}
131 
132 <S0>auto	return (DT_KEY_AUTO);
133 <S0>break	return (DT_KEY_BREAK);
134 <S0>case	return (DT_KEY_CASE);
135 <S0>char	return (DT_KEY_CHAR);
136 <S0>const	return (DT_KEY_CONST);
137 <S0>continue	return (DT_KEY_CONTINUE);
138 <S0>counter	return (DT_KEY_COUNTER);
139 <S0>default	return (DT_KEY_DEFAULT);
140 <S0>do		return (DT_KEY_DO);
141 <S0>double	return (DT_KEY_DOUBLE);
142 <S0>else	return (DT_KEY_ELSE);
143 <S0>enum	return (DT_KEY_ENUM);
144 <S0>extern	return (DT_KEY_EXTERN);
145 <S0>float	return (DT_KEY_FLOAT);
146 <S0>for		return (DT_KEY_FOR);
147 <S0>goto	return (DT_KEY_GOTO);
148 <S0>if		return (DT_KEY_IF);
149 <S0>import	return (DT_KEY_IMPORT);
150 <S0>inline	return (DT_KEY_INLINE);
151 <S0>int		return (DT_KEY_INT);
152 <S0>long	return (DT_KEY_LONG);
153 <S0>offsetof	return (DT_TOK_OFFSETOF);
154 <S0>probe	return (DT_KEY_PROBE);
155 <S0>provider	return (DT_KEY_PROVIDER);
156 <S0>register	return (DT_KEY_REGISTER);
157 <S0>restrict	return (DT_KEY_RESTRICT);
158 <S0>return	return (DT_KEY_RETURN);
159 <S0>self	return (DT_KEY_SELF);
160 <S0>short	return (DT_KEY_SHORT);
161 <S0>signed	return (DT_KEY_SIGNED);
162 <S0>sizeof	return (DT_TOK_SIZEOF);
163 <S0>static	return (DT_KEY_STATIC);
164 <S0>string	return (DT_KEY_STRING);
165 <S0>stringof	return (DT_TOK_STRINGOF);
166 <S0>struct	return (DT_KEY_STRUCT);
167 <S0>switch	return (DT_KEY_SWITCH);
168 <S0>this	return (DT_KEY_THIS);
169 <S0>translator	return (DT_KEY_XLATOR);
170 <S0>typedef	return (DT_KEY_TYPEDEF);
171 <S0>union	return (DT_KEY_UNION);
172 <S0>unsigned	return (DT_KEY_UNSIGNED);
173 <S0>void	return (DT_KEY_VOID);
174 <S0>volatile	return (DT_KEY_VOLATILE);
175 <S0>while	return (DT_KEY_WHILE);
176 <S0>xlate	return (DT_TOK_XLATE);
177 
178 <S2>auto	{ yybegin(YYS_EXPR);	return (DT_KEY_AUTO); }
179 <S2>char	{ yybegin(YYS_EXPR);	return (DT_KEY_CHAR); }
180 <S2>const	{ yybegin(YYS_EXPR);	return (DT_KEY_CONST); }
181 <S2>counter	{ yybegin(YYS_DEFINE);	return (DT_KEY_COUNTER); }
182 <S2>double	{ yybegin(YYS_EXPR);	return (DT_KEY_DOUBLE); }
183 <S2>enum	{ yybegin(YYS_EXPR);	return (DT_KEY_ENUM); }
184 <S2>extern	{ yybegin(YYS_EXPR);	return (DT_KEY_EXTERN); }
185 <S2>float	{ yybegin(YYS_EXPR);	return (DT_KEY_FLOAT); }
186 <S2>import	{ yybegin(YYS_EXPR);	return (DT_KEY_IMPORT); }
187 <S2>inline	{ yybegin(YYS_DEFINE);	return (DT_KEY_INLINE); }
188 <S2>int		{ yybegin(YYS_EXPR);	return (DT_KEY_INT); }
189 <S2>long	{ yybegin(YYS_EXPR);	return (DT_KEY_LONG); }
190 <S2>provider	{ yybegin(YYS_DEFINE);	return (DT_KEY_PROVIDER); }
191 <S2>register	{ yybegin(YYS_EXPR);	return (DT_KEY_REGISTER); }
192 <S2>restrict	{ yybegin(YYS_EXPR);	return (DT_KEY_RESTRICT); }
193 <S2>self	{ yybegin(YYS_EXPR);	return (DT_KEY_SELF); }
194 <S2>short	{ yybegin(YYS_EXPR);	return (DT_KEY_SHORT); }
195 <S2>signed	{ yybegin(YYS_EXPR);	return (DT_KEY_SIGNED); }
196 <S2>static	{ yybegin(YYS_EXPR);	return (DT_KEY_STATIC); }
197 <S2>string	{ yybegin(YYS_EXPR);	return (DT_KEY_STRING); }
198 <S2>struct	{ yybegin(YYS_EXPR);	return (DT_KEY_STRUCT); }
199 <S2>this	{ yybegin(YYS_EXPR);	return (DT_KEY_THIS); }
200 <S2>translator	{ yybegin(YYS_DEFINE);	return (DT_KEY_XLATOR); }
201 <S2>typedef	{ yybegin(YYS_EXPR);	return (DT_KEY_TYPEDEF); }
202 <S2>union	{ yybegin(YYS_EXPR);	return (DT_KEY_UNION); }
203 <S2>unsigned	{ yybegin(YYS_EXPR);	return (DT_KEY_UNSIGNED); }
204 <S2>void	{ yybegin(YYS_EXPR);	return (DT_KEY_VOID); }
205 <S2>volatile	{ yybegin(YYS_EXPR);	return (DT_KEY_VOLATILE); }
206 
207 <S0>"$$"[0-9]+	{
208 			int i = atoi(yytext + 2);
209 			char *v = "";
210 
211 			/*
212 			 * A macro argument reference substitutes the text of
213 			 * an argument in place of the current token.  When we
214 			 * see $$<d> we fetch the saved string from pcb_sargv
215 			 * (or use the default argument if the option has been
216 			 * set and the argument hasn't been specified) and
217 			 * return a token corresponding to this string.
218 			 */
219 			if (i < 0 || (i >= yypcb->pcb_sargc &&
220 			    !(yypcb->pcb_cflags & DTRACE_C_DEFARG))) {
221 				xyerror(D_MACRO_UNDEF, "macro argument %s is "
222 				    "not defined\n", yytext);
223 			}
224 
225 			if (i < yypcb->pcb_sargc) {
226 				v = yypcb->pcb_sargv[i]; /* get val from pcb */
227 				yypcb->pcb_sflagv[i] |= DT_IDFLG_REF;
228 			}
229 
230 			if ((yylval.l_str = strdup(v)) == NULL)
231 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
232 
233 			(void) stresc2chr(yylval.l_str);
234 			return (DT_TOK_STRING);
235 		}
236 
237 <S0>"$"[0-9]+	{
238 			int i = atoi(yytext + 1);
239 			char *p, *v = "0";
240 
241 			/*
242 			 * A macro argument reference substitutes the text of
243 			 * one identifier or integer pattern for another.  When
244 			 * we see $<d> we fetch the saved string from pcb_sargv
245 			 * (or use the default argument if the option has been
246 			 * set and the argument hasn't been specified) and
247 			 * return a token corresponding to this string.
248 			 */
249 			if (i < 0 || (i >= yypcb->pcb_sargc &&
250 			    !(yypcb->pcb_cflags & DTRACE_C_DEFARG))) {
251 				xyerror(D_MACRO_UNDEF, "macro argument %s is "
252 				    "not defined\n", yytext);
253 			}
254 
255 			if (i < yypcb->pcb_sargc) {
256 				v = yypcb->pcb_sargv[i]; /* get val from pcb */
257 				yypcb->pcb_sflagv[i] |= DT_IDFLG_REF;
258 			}
259 
260 			/*
261 			 * If the macro text is not a valid integer or ident,
262 			 * then we treat it as a string.  The string may be
263 			 * optionally enclosed in quotes, which we strip.
264 			 */
265 			if (strbadidnum(v)) {
266 				size_t len = strlen(v);
267 
268 				if (len != 1 && *v == '"' && v[len - 1] == '"')
269 					yylval.l_str = strndup(v + 1, len - 2);
270 				else
271 					yylval.l_str = strndup(v, len);
272 
273 				if (yylval.l_str == NULL)
274 					longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
275 
276 				(void) stresc2chr(yylval.l_str);
277 				return (DT_TOK_STRING);
278 			}
279 
280 			/*
281 			 * If the macro text is not a string an begins with a
282 			 * digit or a +/- sign, process it as an integer token.
283 			 */
284 			if (isdigit(v[0]) || v[0] == '-' || v[0] == '+') {
285 				if (isdigit(v[0]))
286 					yyintprefix = 0;
287 				else
288 					yyintprefix = *v++;
289 
290 				errno = 0;
291 				yylval.l_int = strtoull(v, &p, 0);
292 				(void) strncpy(yyintsuffix, p,
293 				    sizeof (yyintsuffix));
294 				yyintdecimal = *v != '0';
295 
296 				if (errno == ERANGE) {
297 					xyerror(D_MACRO_OFLOW, "macro argument"
298 					    " %s constant %s results in integer"
299 					    " overflow\n", yytext, v);
300 				}
301 
302 				return (DT_TOK_INT);
303 			}
304 
305 			return (id_or_type(v));
306 		}
307 
308 <S0>"$$"{RGX_IDENT} {
309 			dt_ident_t *idp = dt_idhash_lookup(
310 			    yypcb->pcb_hdl->dt_macros, yytext + 2);
311 
312 			char s[16]; /* enough for UINT_MAX + \0 */
313 
314 			if (idp == NULL) {
315 				xyerror(D_MACRO_UNDEF, "macro variable %s "
316 				    "is not defined\n", yytext);
317 			}
318 
319 			/*
320 			 * For the moment, all current macro variables are of
321 			 * type id_t (refer to dtrace_update() for details).
322 			 */
323 			(void) snprintf(s, sizeof (s), "%u", idp->di_id);
324 			if ((yylval.l_str = strdup(s)) == NULL)
325 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
326 
327 			return (DT_TOK_STRING);
328 		}
329 
330 <S0>"$"{RGX_IDENT} {
331 			dt_ident_t *idp = dt_idhash_lookup(
332 			    yypcb->pcb_hdl->dt_macros, yytext + 1);
333 
334 			if (idp == NULL) {
335 				xyerror(D_MACRO_UNDEF, "macro variable %s "
336 				    "is not defined\n", yytext);
337 			}
338 
339 			/*
340 			 * For the moment, all current macro variables are of
341 			 * type id_t (refer to dtrace_update() for details).
342 			 */
343 			yylval.l_int = (intmax_t)(int)idp->di_id;
344 			yyintprefix = 0;
345 			yyintsuffix[0] = '\0';
346 			yyintdecimal = 1;
347 
348 			return (DT_TOK_INT);
349 		}
350 
351 <S0>{RGX_IDENT}	{
352 			return (id_or_type(yytext));
353 		}
354 
355 <S0>{RGX_AGG}	{
356 			if ((yylval.l_str = strdup(yytext)) == NULL)
357 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
358 			return (DT_TOK_AGG);
359 		}
360 
361 <S0>"@"		{
362 			if ((yylval.l_str = strdup("@_")) == NULL)
363 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
364 			return (DT_TOK_AGG);
365 		}
366 
367 <S0>{RGX_INT}	|
368 <S2>{RGX_INT}	|
369 <S3>{RGX_INT}	{
370 			char *p;
371 
372 			errno = 0;
373 			yylval.l_int = strtoull(yytext, &p, 0);
374 			yyintprefix = 0;
375 			(void) strncpy(yyintsuffix, p, sizeof (yyintsuffix));
376 			yyintdecimal = yytext[0] != '0';
377 
378 			if (errno == ERANGE) {
379 				xyerror(D_INT_OFLOW, "constant %s results in "
380 				    "integer overflow\n", yytext);
381 			}
382 
383 			if (*p != '\0' && strchr("uUlL", *p) == NULL) {
384 				xyerror(D_INT_DIGIT, "constant %s contains "
385 				    "invalid digit %c\n", yytext, *p);
386 			}
387 
388 			if ((YYSTATE) != S3)
389 				return (DT_TOK_INT);
390 
391 			yypragma = dt_node_link(yypragma,
392 			    dt_node_int(yylval.l_int));
393 		}
394 
395 <S0>{RGX_FP}	yyerror("floating-point constants are not permitted\n");
396 
397 <S0>\"{RGX_STR}$ |
398 <S3>\"{RGX_STR}$ xyerror(D_STR_NL, "newline encountered in string literal");
399 
400 <S0>\"{RGX_STR}\" |
401 <S3>\"{RGX_STR}\" {
402 			/*
403 			 * Quoted string -- convert C escape sequences and
404 			 * return the string as a token.
405 			 */
406 			yylval.l_str = strndup(yytext + 1, yyleng - 2);
407 
408 			if (yylval.l_str == NULL)
409 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
410 
411 			(void) stresc2chr(yylval.l_str);
412 			if ((YYSTATE) != S3)
413 				return (DT_TOK_STRING);
414 
415 			yypragma = dt_node_link(yypragma,
416 			    dt_node_string(yylval.l_str));
417 		}
418 
419 <S0>'{RGX_CHR}$	xyerror(D_CHR_NL, "newline encountered in character constant");
420 
421 <S0>'{RGX_CHR}'	{
422 			char *s, *p, *q;
423 			size_t nbytes;
424 
425 			/*
426 			 * Character constant -- convert C escape sequences and
427 			 * return the character as an integer immediate value.
428 			 */
429 			if (yyleng == 2)
430 				xyerror(D_CHR_NULL, "empty character constant");
431 
432 			s = yytext + 1;
433 			yytext[yyleng - 1] = '\0';
434 			nbytes = stresc2chr(s);
435 			yylval.l_int = 0;
436 			yyintprefix = 0;
437 			yyintsuffix[0] = '\0';
438 			yyintdecimal = 1;
439 
440 			if (nbytes > sizeof (yylval.l_int)) {
441 				xyerror(D_CHR_OFLOW, "character constant is "
442 				    "too long");
443 			}
444 #if BYTE_ORDER == _LITTLE_ENDIAN
445 			p = ((char *)&yylval.l_int) + nbytes - 1;
446 			for (q = s; nbytes != 0; nbytes--)
447 				*p-- = *q++;
448 #else
449 			bcopy(s, ((char *)&yylval.l_int) +
450 			    sizeof (yylval.l_int) - nbytes, nbytes);
451 #endif
452 			return (DT_TOK_INT);
453 		}
454 
455 <S0>"/*"	|
456 <S2>"/*"	{
457 			yypcb->pcb_cstate = (YYSTATE);
458 			BEGIN(S1);
459 		}
460 
461 <S0>{RGX_INTERP} |
462 <S2>{RGX_INTERP} ;	/* discard any #! lines */
463 
464 <S0>{RGX_CTL}	|
465 <S2>{RGX_CTL}	|
466 <S4>{RGX_CTL}	{
467 			assert(yypragma == NULL);
468 			yypcb->pcb_cstate = (YYSTATE);
469 			BEGIN(S3);
470 		}
471 
472 <S4>.		;	/* discard */
473 <S4>"\n"	;	/* discard */
474 
475 <S0>"/"		{
476 			int c, tok;
477 
478 			/*
479 			 * The use of "/" as the predicate delimiter and as the
480 			 * integer division symbol requires special lookahead
481 			 * to avoid a shift/reduce conflict in the D grammar.
482 			 * We look ahead to the next non-whitespace character.
483 			 * If we encounter EOF, ";", "{", or "/", then this "/"
484 			 * closes the predicate and we return DT_TOK_EPRED.
485 			 * If we encounter anything else, it's DT_TOK_DIV.
486 			 */
487 			while ((c = input()) != 0) {
488 				if (strchr("\f\n\r\t\v ", c) == NULL)
489 					break;
490 			}
491 
492 			if (c == 0 || c == ';' || c == '{' || c == '/') {
493 				if (yypcb->pcb_parens != 0) {
494 					yyerror("closing ) expected in "
495 					    "predicate before /\n");
496 				}
497 				if (yypcb->pcb_brackets != 0) {
498 					yyerror("closing ] expected in "
499 					    "predicate before /\n");
500 				}
501 				tok = DT_TOK_EPRED;
502 			} else
503 				tok = DT_TOK_DIV;
504 
505 			unput(c);
506 			return (tok);
507 		}
508 
509 <S0>"("		{
510 			yypcb->pcb_parens++;
511 			return (DT_TOK_LPAR);
512 		}
513 
514 <S0>")"		{
515 			if (--yypcb->pcb_parens < 0)
516 				yyerror("extra ) in input stream\n");
517 			return (DT_TOK_RPAR);
518 		}
519 
520 <S0>"["		{
521 			yypcb->pcb_brackets++;
522 			return (DT_TOK_LBRAC);
523 		}
524 
525 <S0>"]"		{
526 			if (--yypcb->pcb_brackets < 0)
527 				yyerror("extra ] in input stream\n");
528 			return (DT_TOK_RBRAC);
529 		}
530 
531 <S0>"{"		|
532 <S2>"{"		{
533 			yypcb->pcb_braces++;
534 			return ('{');
535 		}
536 
537 <S0>"}"		{
538 			if (--yypcb->pcb_braces < 0)
539 				yyerror("extra } in input stream\n");
540 			return ('}');
541 		}
542 
543 <S0>"|"		return (DT_TOK_BOR);
544 <S0>"^"		return (DT_TOK_XOR);
545 <S0>"&"		return (DT_TOK_BAND);
546 <S0>"&&"	return (DT_TOK_LAND);
547 <S0>"^^"	return (DT_TOK_LXOR);
548 <S0>"||"	return (DT_TOK_LOR);
549 <S0>"=="	return (DT_TOK_EQU);
550 <S0>"!="	return (DT_TOK_NEQ);
551 <S0>"<"		return (DT_TOK_LT);
552 <S0>"<="	return (DT_TOK_LE);
553 <S0>">"		return (DT_TOK_GT);
554 <S0>">="	return (DT_TOK_GE);
555 <S0>"<<"	return (DT_TOK_LSH);
556 <S0>">>"	return (DT_TOK_RSH);
557 <S0>"+"		return (DT_TOK_ADD);
558 <S0>"-"		return (DT_TOK_SUB);
559 <S0>"*"		return (DT_TOK_MUL);
560 <S0>"%"		return (DT_TOK_MOD);
561 <S0>"~"		return (DT_TOK_BNEG);
562 <S0>"!"		return (DT_TOK_LNEG);
563 <S0>"?"		return (DT_TOK_QUESTION);
564 <S0>":"		return (DT_TOK_COLON);
565 <S0>"."		return (DT_TOK_DOT);
566 <S0>"->"	return (DT_TOK_PTR);
567 <S0>"="		return (DT_TOK_ASGN);
568 <S0>"+="	return (DT_TOK_ADD_EQ);
569 <S0>"-="	return (DT_TOK_SUB_EQ);
570 <S0>"*="	return (DT_TOK_MUL_EQ);
571 <S0>"/="	return (DT_TOK_DIV_EQ);
572 <S0>"%="	return (DT_TOK_MOD_EQ);
573 <S0>"&="	return (DT_TOK_AND_EQ);
574 <S0>"^="	return (DT_TOK_XOR_EQ);
575 <S0>"|="	return (DT_TOK_OR_EQ);
576 <S0>"<<="	return (DT_TOK_LSH_EQ);
577 <S0>">>="	return (DT_TOK_RSH_EQ);
578 <S0>"++"	return (DT_TOK_ADDADD);
579 <S0>"--"	return (DT_TOK_SUBSUB);
580 <S0>"..."	return (DT_TOK_ELLIPSIS);
581 <S0>","		return (DT_TOK_COMMA);
582 <S0>";"		return (';');
583 <S0>{RGX_WS}	; /* discard */
584 <S0>"\\"\n	; /* discard */
585 <S0>.		yyerror("syntax error near \"%c\"\n", yytext[0]);
586 
587 <S1>"/*"	yyerror("/* encountered inside a comment\n");
588 <S1>"*/"	BEGIN(yypcb->pcb_cstate);
589 <S1>.|\n	; /* discard */
590 
591 <S2>{RGX_PSPEC}	{
592 			/*
593 			 * S2 has an ambiguity because RGX_PSPEC includes '*'
594 			 * as a glob character and '*' also can be DT_TOK_STAR.
595 			 * Since lex always matches the longest token, this
596 			 * rule can be matched by an input string like "int*",
597 			 * which could begin a global variable declaration such
598 			 * as "int*x;" or could begin a RGX_PSPEC with globbing
599 			 * such as "int* { trace(timestamp); }".  If C_PSPEC is
600 			 * not set, we must resolve the ambiguity in favor of
601 			 * the type and perform lexer pushback if the fragment
602 			 * before '*' or entire fragment matches a type name.
603 			 * If C_PSPEC is set, we always return a PSPEC token.
604 			 * If C_PSPEC is off, the user can avoid ambiguity by
605 			 * including a ':' delimiter in the specifier, which
606 			 * they should be doing anyway to specify the provider.
607 			 */
608 			if (!(yypcb->pcb_cflags & DTRACE_C_PSPEC) &&
609 			    strchr(yytext, ':') == NULL) {
610 
611 				char *p = strchr(yytext, '*');
612 				char *q = yytext + yyleng - 1;
613 
614 				if (p != NULL && p > yytext)
615 					*p = '\0'; /* prune yytext */
616 
617 				if (dt_type_lookup(yytext, NULL) == 0) {
618 					yylval.l_str = strdup(yytext);
619 
620 					if (yylval.l_str == NULL) {
621 						longjmp(yypcb->pcb_jmpbuf,
622 						    EDT_NOMEM);
623 					}
624 
625 					if (p != NULL && p > yytext) {
626 						for (*p = '*'; q >= p; q--)
627 							unput(*q);
628 					}
629 
630 					yybegin(YYS_EXPR);
631 					return (DT_TOK_TNAME);
632 				}
633 
634 				if (p != NULL && p > yytext)
635 					*p = '*'; /* restore yytext */
636 			}
637 
638 			if ((yylval.l_str = strdup(yytext)) == NULL)
639 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
640 
641 			return (DT_TOK_PSPEC);
642 		}
643 
644 <S2>"/"		return (DT_TOK_DIV);
645 <S2>","		return (DT_TOK_COMMA);
646 
647 <S2>{RGX_WS}	; /* discard */
648 <S2>.		yyerror("syntax error near \"%c\"\n", yytext[0]);
649 
650 <S3>\n		{
651 			dt_pragma(yypragma);
652 			yypragma = NULL;
653 			BEGIN(yypcb->pcb_cstate);
654 		}
655 
656 <S3>[\f\t\v ]+	; /* discard */
657 
658 <S3>[^\f\n\t\v "]+ {
659 			dt_node_t *dnp;
660 
661 			if ((yylval.l_str = strdup(yytext)) == NULL)
662 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
663 
664 			/*
665 			 * We want to call dt_node_ident() here, but we can't
666 			 * because it will expand inlined identifiers, which we
667 			 * don't want to do from #pragma context in order to
668 			 * support pragmas that apply to the ident itself.  We
669 			 * call dt_node_string() and then reset dn_op instead.
670 			 */
671 			dnp = dt_node_string(yylval.l_str);
672 			dnp->dn_kind = DT_NODE_IDENT;
673 			dnp->dn_op = DT_TOK_IDENT;
674 			yypragma = dt_node_link(yypragma, dnp);
675 		}
676 
677 <S3>.		yyerror("syntax error near \"%c\"\n", yytext[0]);
678 
679 %%
680 
681 /*
682  * yybegin provides a wrapper for use from C code around the lex BEGIN() macro.
683  * We use two main states for lexing because probe descriptions use a syntax
684  * that is incompatible with the normal D tokens (e.g. names can contain "-").
685  * yybegin also handles the job of switching between two lists of dt_nodes
686  * as we allocate persistent definitions, like inlines, and transient nodes
687  * that will be freed once we are done parsing the current program file.
688  */
689 void
690 yybegin(yystate_t state)
691 {
692 #ifdef	YYDEBUG
693 	yydebug = _dtrace_debug;
694 #endif
695 	if (yypcb->pcb_yystate == state)
696 		return; /* nothing to do if we're in the state already */
697 
698 	if (yypcb->pcb_yystate == YYS_DEFINE) {
699 		yypcb->pcb_list = yypcb->pcb_hold;
700 		yypcb->pcb_hold = NULL;
701 	}
702 
703 	switch (state) {
704 	case YYS_CLAUSE:
705 		BEGIN(S2);
706 		break;
707 	case YYS_DEFINE:
708 		assert(yypcb->pcb_hold == NULL);
709 		yypcb->pcb_hold = yypcb->pcb_list;
710 		yypcb->pcb_list = NULL;
711 		/*FALLTHRU*/
712 	case YYS_EXPR:
713 		BEGIN(S0);
714 		break;
715 	case YYS_DONE:
716 		break;
717 	case YYS_CONTROL:
718 		BEGIN(S4);
719 		break;
720 	default:
721 		xyerror(D_UNKNOWN, "internal error -- bad yystate %d\n", state);
722 	}
723 
724 	yypcb->pcb_yystate = state;
725 }
726 
727 void
728 yyinit(dt_pcb_t *pcb)
729 {
730 	yypcb = pcb;
731 	yylineno = 1;
732 	yypragma = NULL;
733 #if defined(sun)
734 	yysptr = yysbuf;
735 #endif
736 }
737 
738 /*
739  * Given a lexeme 's' (typically yytext), set yylval and return an appropriate
740  * token to the parser indicating either an identifier or a typedef name.
741  * User-defined global variables always take precedence over types, but we do
742  * use some heuristics because D programs can look at an ever-changing set of
743  * kernel types and also can implicitly instantiate variables by assignment,
744  * unlike in C.  The code here is ordered carefully as lookups are not cheap.
745  */
746 static int
747 id_or_type(const char *s)
748 {
749 	dtrace_hdl_t *dtp = yypcb->pcb_hdl;
750 	dt_decl_t *ddp = yypcb->pcb_dstack.ds_decl;
751 	int c0, c1, ttok = DT_TOK_TNAME;
752 	dt_ident_t *idp;
753 
754 	if ((s = yylval.l_str = strdup(s)) == NULL)
755 		longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
756 
757 	/*
758 	 * If the lexeme is a global variable or likely identifier or *not* a
759 	 * type_name, then it is an identifier token.
760 	 */
761 	if (dt_idstack_lookup(&yypcb->pcb_globals, s) != NULL ||
762 	    dt_idhash_lookup(yypcb->pcb_idents, s) != NULL ||
763 	    dt_type_lookup(s, NULL) != 0)
764 		return (DT_TOK_IDENT);
765 
766 	/*
767 	 * If we're in the midst of parsing a declaration and a type_specifier
768 	 * has already been shifted, then return DT_TOK_IDENT instead of TNAME.
769 	 * This semantic is necessary to permit valid ISO C code such as:
770 	 *
771 	 * typedef int foo;
772 	 * struct s { foo foo; };
773 	 *
774 	 * without causing shift/reduce conflicts in the direct_declarator part
775 	 * of the grammar.  The result is that we must check for conflicting
776 	 * redeclarations of the same identifier as part of dt_node_decl().
777 	 */
778 	if (ddp != NULL && ddp->dd_name != NULL)
779 		return (DT_TOK_IDENT);
780 
781 	/*
782 	 * If the lexeme is a type name and we are not in a program clause,
783 	 * then always interpret it as a type and return DT_TOK_TNAME.
784 	 */
785 	if ((YYSTATE) != S0)
786 		return (DT_TOK_TNAME);
787 
788 	/*
789 	 * If the lexeme matches a type name but is in a program clause, then
790 	 * it could be a type or it could be an undefined variable.  Peek at
791 	 * the next token to decide.  If we see ++, --, [, or =, we know there
792 	 * might be an assignment that is trying to create a global variable,
793 	 * so we optimistically return DT_TOK_IDENT.  There is no harm in being
794 	 * wrong: a type_name followed by ++, --, [, or = is a syntax error.
795 	 */
796 	while ((c0 = input()) != 0) {
797 		if (strchr("\f\n\r\t\v ", c0) == NULL)
798 			break;
799 	}
800 
801 	switch (c0) {
802 	case '+':
803 	case '-':
804 		if ((c1 = input()) == c0)
805 			ttok = DT_TOK_IDENT;
806 		unput(c1);
807 		break;
808 
809 	case '=':
810 		if ((c1 = input()) != c0)
811 			ttok = DT_TOK_IDENT;
812 		unput(c1);
813 		break;
814 	case '[':
815 		ttok = DT_TOK_IDENT;
816 		break;
817 	}
818 
819 	if (ttok == DT_TOK_IDENT) {
820 		idp = dt_idhash_insert(yypcb->pcb_idents, s, DT_IDENT_SCALAR, 0,
821 		    0, _dtrace_defattr, 0, &dt_idops_thaw, NULL, dtp->dt_gen);
822 
823 		if (idp == NULL)
824 			longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
825 	}
826 
827 	unput(c0);
828 	return (ttok);
829 }
830 
831 #if defined(sun)
832 static int
833 input(void)
834 {
835 	int c;
836 
837 	if (yysptr > yysbuf)
838 		c = *--yysptr;
839 	else if (yypcb->pcb_fileptr != NULL)
840 		c = fgetc(yypcb->pcb_fileptr);
841 	else if (yypcb->pcb_strptr < yypcb->pcb_string + yypcb->pcb_strlen)
842 		c = *yypcb->pcb_strptr++;
843 	else
844 		c = EOF;
845 
846 	if (c == '\n')
847 		yylineno++;
848 
849 	if (c != EOF)
850 		return (c);
851 
852 	if ((YYSTATE) == S1)
853 		yyerror("end-of-file encountered before matching */\n");
854 
855 	if ((YYSTATE) == S3)
856 		yyerror("end-of-file encountered before end of control line\n");
857 
858 	if (yypcb->pcb_fileptr != NULL && ferror(yypcb->pcb_fileptr))
859 		longjmp(yypcb->pcb_jmpbuf, EDT_FIO);
860 
861 	return (0); /* EOF */
862 }
863 
864 static void
865 unput(int c)
866 {
867 	if (c == '\n')
868 		yylineno--;
869 
870 	*yysptr++ = c;
871 	yytchar = c;
872 }
873 #endif
874