xref: /titanic_41/usr/src/lib/libdtrace/common/dt_lex.l (revision 6ab3986229f6d7d9a83c94e3a6e68fd05da5cff0)
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 
23 /*
24  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
25  */
26 /*
27  * Copyright (c) 2013 by Delphix. All rights reserved.
28  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
29  */
30 
31 #include <string.h>
32 #include <stdlib.h>
33 #include <stdio.h>
34 #include <assert.h>
35 #include <ctype.h>
36 #include <errno.h>
37 
38 #include <dt_impl.h>
39 #include <dt_grammar.h>
40 #include <dt_parser.h>
41 #include <dt_string.h>
42 
43 /*
44  * We need to undefine lex's input and unput macros so that references to these
45  * call the functions provided at the end of this source file.
46  */
47 #undef input
48 #undef unput
49 
50 static int id_or_type(const char *);
51 static int input(void);
52 static void unput(int);
53 
54 /*
55  * We first define a set of labeled states for use in the D lexer and then a
56  * set of regular expressions to simplify things below. The lexer states are:
57  *
58  * S0 - D program clause and expression lexing
59  * S1 - D comments (i.e. skip everything until end of comment)
60  * S2 - D program outer scope (probe specifiers and declarations)
61  * S3 - D control line parsing (i.e. after ^# is seen but before \n)
62  * S4 - D control line scan (locate control directives only and invoke S3)
63  */
64 %}
65 
66 %e 1500		/* maximum nodes */
67 %p 4900		/* maximum positions */
68 %n 600		/* maximum states */
69 %a 3000		/* maximum transitions */
70 
71 %s S0 S1 S2 S3 S4
72 
73 RGX_AGG		"@"[a-zA-Z_][0-9a-zA-Z_]*
74 RGX_PSPEC	[-$:a-zA-Z_.?*\\\[\]!][-$:0-9a-zA-Z_.`?*\\\[\]!]*
75 RGX_ALTIDENT	[a-zA-Z_][0-9a-zA-Z_]*
76 RGX_LMID	LM[0-9a-fA-F]+`
77 RGX_MOD_IDENT	[a-zA-Z_`][0-9a-z.A-Z_`]*`
78 RGX_IDENT	[a-zA-Z_`][0-9a-zA-Z_`]*
79 RGX_INT		([0-9]+|0[xX][0-9A-Fa-f]+)[uU]?[lL]?[lL]?
80 RGX_FP		([0-9]+("."?)[0-9]*|"."[0-9]+)((e|E)("+"|-)?[0-9]+)?[fFlL]?
81 RGX_WS		[\f\n\r\t\v ]
82 RGX_STR		([^"\\\n]|\\[^"\n]|\\\")*
83 RGX_CHR		([^'\\\n]|\\[^'\n]|\\')*
84 RGX_INTERP	^[\f\t\v ]*#!.*
85 RGX_CTL		^[\f\t\v ]*#
86 
87 %%
88 
89 %{
90 
91 /*
92  * We insert a special prologue into yylex() itself: if the pcb contains a
93  * context token, we return that prior to running the normal lexer.  This
94  * allows libdtrace to force yacc into one of our three parsing contexts: D
95  * expression (DT_CTX_DEXPR), D program (DT_CTX_DPROG) or D type (DT_CTX_DTYPE).
96  * Once the token is returned, we clear it so this only happens once.
97  */
98 if (yypcb->pcb_token != 0) {
99 	int tok = yypcb->pcb_token;
100 	yypcb->pcb_token = 0;
101 	return (tok);
102 }
103 
104 %}
105 
106 <S0>auto	return (DT_KEY_AUTO);
107 <S0>break	return (DT_KEY_BREAK);
108 <S0>case	return (DT_KEY_CASE);
109 <S0>char	return (DT_KEY_CHAR);
110 <S0>const	return (DT_KEY_CONST);
111 <S0>continue	return (DT_KEY_CONTINUE);
112 <S0>counter	return (DT_KEY_COUNTER);
113 <S0>default	return (DT_KEY_DEFAULT);
114 <S0>do		return (DT_KEY_DO);
115 <S0>double	return (DT_KEY_DOUBLE);
116 <S0>else	return (DT_KEY_ELSE);
117 <S0>enum	return (DT_KEY_ENUM);
118 <S0>extern	return (DT_KEY_EXTERN);
119 <S0>float	return (DT_KEY_FLOAT);
120 <S0>for		return (DT_KEY_FOR);
121 <S0>goto	return (DT_KEY_GOTO);
122 <S0>if		return (DT_KEY_IF);
123 <S0>import	return (DT_KEY_IMPORT);
124 <S0>inline	return (DT_KEY_INLINE);
125 <S0>int		return (DT_KEY_INT);
126 <S0>long	return (DT_KEY_LONG);
127 <S0>offsetof	return (DT_TOK_OFFSETOF);
128 <S0>probe	return (DT_KEY_PROBE);
129 <S0>provider	return (DT_KEY_PROVIDER);
130 <S0>register	return (DT_KEY_REGISTER);
131 <S0>restrict	return (DT_KEY_RESTRICT);
132 <S0>return	return (DT_KEY_RETURN);
133 <S0>self	return (DT_KEY_SELF);
134 <S0>short	return (DT_KEY_SHORT);
135 <S0>signed	return (DT_KEY_SIGNED);
136 <S0>sizeof	return (DT_TOK_SIZEOF);
137 <S0>static	return (DT_KEY_STATIC);
138 <S0>string	return (DT_KEY_STRING);
139 <S0>stringof	return (DT_TOK_STRINGOF);
140 <S0>struct	return (DT_KEY_STRUCT);
141 <S0>switch	return (DT_KEY_SWITCH);
142 <S0>this	return (DT_KEY_THIS);
143 <S0>translator	return (DT_KEY_XLATOR);
144 <S0>typedef	return (DT_KEY_TYPEDEF);
145 <S0>union	return (DT_KEY_UNION);
146 <S0>unsigned	return (DT_KEY_UNSIGNED);
147 <S0>userland	return (DT_KEY_USERLAND);
148 <S0>void	return (DT_KEY_VOID);
149 <S0>volatile	return (DT_KEY_VOLATILE);
150 <S0>while	return (DT_KEY_WHILE);
151 <S0>xlate	return (DT_TOK_XLATE);
152 
153 <S2>auto	{ yybegin(YYS_EXPR);	return (DT_KEY_AUTO); }
154 <S2>char	{ yybegin(YYS_EXPR);	return (DT_KEY_CHAR); }
155 <S2>const	{ yybegin(YYS_EXPR);	return (DT_KEY_CONST); }
156 <S2>counter	{ yybegin(YYS_DEFINE);	return (DT_KEY_COUNTER); }
157 <S2>double	{ yybegin(YYS_EXPR);	return (DT_KEY_DOUBLE); }
158 <S2>enum	{ yybegin(YYS_EXPR);	return (DT_KEY_ENUM); }
159 <S2>extern	{ yybegin(YYS_EXPR);	return (DT_KEY_EXTERN); }
160 <S2>float	{ yybegin(YYS_EXPR);	return (DT_KEY_FLOAT); }
161 <S2>import	{ yybegin(YYS_EXPR);	return (DT_KEY_IMPORT); }
162 <S2>inline	{ yybegin(YYS_DEFINE);	return (DT_KEY_INLINE); }
163 <S2>int		{ yybegin(YYS_EXPR);	return (DT_KEY_INT); }
164 <S2>long	{ yybegin(YYS_EXPR);	return (DT_KEY_LONG); }
165 <S2>provider	{ yybegin(YYS_DEFINE);	return (DT_KEY_PROVIDER); }
166 <S2>register	{ yybegin(YYS_EXPR);	return (DT_KEY_REGISTER); }
167 <S2>restrict	{ yybegin(YYS_EXPR);	return (DT_KEY_RESTRICT); }
168 <S2>self	{ yybegin(YYS_EXPR);	return (DT_KEY_SELF); }
169 <S2>short	{ yybegin(YYS_EXPR);	return (DT_KEY_SHORT); }
170 <S2>signed	{ yybegin(YYS_EXPR);	return (DT_KEY_SIGNED); }
171 <S2>static	{ yybegin(YYS_EXPR);	return (DT_KEY_STATIC); }
172 <S2>string	{ yybegin(YYS_EXPR);	return (DT_KEY_STRING); }
173 <S2>struct	{ yybegin(YYS_EXPR);	return (DT_KEY_STRUCT); }
174 <S2>this	{ yybegin(YYS_EXPR);	return (DT_KEY_THIS); }
175 <S2>translator	{ yybegin(YYS_DEFINE);	return (DT_KEY_XLATOR); }
176 <S2>typedef	{ yybegin(YYS_EXPR);	return (DT_KEY_TYPEDEF); }
177 <S2>union	{ yybegin(YYS_EXPR);	return (DT_KEY_UNION); }
178 <S2>unsigned	{ yybegin(YYS_EXPR);	return (DT_KEY_UNSIGNED); }
179 <S2>void	{ yybegin(YYS_EXPR);	return (DT_KEY_VOID); }
180 <S2>volatile	{ yybegin(YYS_EXPR);	return (DT_KEY_VOLATILE); }
181 
182 <S0>"$$"[0-9]+	{
183 			int i = atoi(yytext + 2);
184 			char *v = "";
185 
186 			/*
187 			 * A macro argument reference substitutes the text of
188 			 * an argument in place of the current token.  When we
189 			 * see $$<d> we fetch the saved string from pcb_sargv
190 			 * (or use the default argument if the option has been
191 			 * set and the argument hasn't been specified) and
192 			 * return a token corresponding to this string.
193 			 */
194 			if (i < 0 || (i >= yypcb->pcb_sargc &&
195 			    !(yypcb->pcb_cflags & DTRACE_C_DEFARG))) {
196 				xyerror(D_MACRO_UNDEF, "macro argument %s is "
197 				    "not defined\n", yytext);
198 			}
199 
200 			if (i < yypcb->pcb_sargc) {
201 				v = yypcb->pcb_sargv[i]; /* get val from pcb */
202 				yypcb->pcb_sflagv[i] |= DT_IDFLG_REF;
203 			}
204 
205 			if ((yylval.l_str = strdup(v)) == NULL)
206 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
207 
208 			(void) stresc2chr(yylval.l_str);
209 			return (DT_TOK_STRING);
210 		}
211 
212 <S0>"$"[0-9]+	{
213 			int i = atoi(yytext + 1);
214 			char *p, *v = "0";
215 
216 			/*
217 			 * A macro argument reference substitutes the text of
218 			 * one identifier or integer pattern for another.  When
219 			 * we see $<d> we fetch the saved string from pcb_sargv
220 			 * (or use the default argument if the option has been
221 			 * set and the argument hasn't been specified) and
222 			 * return a token corresponding to this string.
223 			 */
224 			if (i < 0 || (i >= yypcb->pcb_sargc &&
225 			    !(yypcb->pcb_cflags & DTRACE_C_DEFARG))) {
226 				xyerror(D_MACRO_UNDEF, "macro argument %s is "
227 				    "not defined\n", yytext);
228 			}
229 
230 			if (i < yypcb->pcb_sargc) {
231 				v = yypcb->pcb_sargv[i]; /* get val from pcb */
232 				yypcb->pcb_sflagv[i] |= DT_IDFLG_REF;
233 			}
234 
235 			/*
236 			 * If the macro text is not a valid integer or ident,
237 			 * then we treat it as a string.  The string may be
238 			 * optionally enclosed in quotes, which we strip.
239 			 */
240 			if (strbadidnum(v)) {
241 				size_t len = strlen(v);
242 
243 				if (len != 1 && *v == '"' && v[len - 1] == '"')
244 					yylval.l_str = strndup(v + 1, len - 2);
245 				else
246 					yylval.l_str = strndup(v, len);
247 
248 				if (yylval.l_str == NULL)
249 					longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
250 
251 				(void) stresc2chr(yylval.l_str);
252 				return (DT_TOK_STRING);
253 			}
254 
255 			/*
256 			 * If the macro text is not a string an begins with a
257 			 * digit or a +/- sign, process it as an integer token.
258 			 */
259 			if (isdigit(v[0]) || v[0] == '-' || v[0] == '+') {
260 				if (isdigit(v[0]))
261 					yyintprefix = 0;
262 				else
263 					yyintprefix = *v++;
264 
265 				errno = 0;
266 				yylval.l_int = strtoull(v, &p, 0);
267 				(void) strncpy(yyintsuffix, p,
268 				    sizeof (yyintsuffix));
269 				yyintdecimal = *v != '0';
270 
271 				if (errno == ERANGE) {
272 					xyerror(D_MACRO_OFLOW, "macro argument"
273 					    " %s constant %s results in integer"
274 					    " overflow\n", yytext, v);
275 				}
276 
277 				return (DT_TOK_INT);
278 			}
279 
280 			return (id_or_type(v));
281 		}
282 
283 <S0>"$$"{RGX_IDENT} {
284 			dt_ident_t *idp = dt_idhash_lookup(
285 			    yypcb->pcb_hdl->dt_macros, yytext + 2);
286 
287 			char s[16]; /* enough for UINT_MAX + \0 */
288 
289 			if (idp == NULL) {
290 				xyerror(D_MACRO_UNDEF, "macro variable %s "
291 				    "is not defined\n", yytext);
292 			}
293 
294 			/*
295 			 * For the moment, all current macro variables are of
296 			 * type id_t (refer to dtrace_update() for details).
297 			 */
298 			(void) snprintf(s, sizeof (s), "%u", idp->di_id);
299 			if ((yylval.l_str = strdup(s)) == NULL)
300 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
301 
302 			return (DT_TOK_STRING);
303 		}
304 
305 <S0>"$"{RGX_IDENT} {
306 			dt_ident_t *idp = dt_idhash_lookup(
307 			    yypcb->pcb_hdl->dt_macros, yytext + 1);
308 
309 			if (idp == NULL) {
310 				xyerror(D_MACRO_UNDEF, "macro variable %s "
311 				    "is not defined\n", yytext);
312 			}
313 
314 			/*
315 			 * For the moment, all current macro variables are of
316 			 * type id_t (refer to dtrace_update() for details).
317 			 */
318 			yylval.l_int = (intmax_t)(int)idp->di_id;
319 			yyintprefix = 0;
320 			yyintsuffix[0] = '\0';
321 			yyintdecimal = 1;
322 
323 			return (DT_TOK_INT);
324 		}
325 
326 <S0>{RGX_IDENT} |
327 <S0>{RGX_MOD_IDENT}{RGX_IDENT} |
328 <S0>{RGX_MOD_IDENT} {
329 			return (id_or_type(yytext));
330 		}
331 
332 <S0>{RGX_AGG}	{
333 			if ((yylval.l_str = strdup(yytext)) == NULL)
334 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
335 			return (DT_TOK_AGG);
336 		}
337 
338 <S0>"@"		{
339 			if ((yylval.l_str = strdup("@_")) == NULL)
340 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
341 			return (DT_TOK_AGG);
342 		}
343 
344 <S0>{RGX_INT}	|
345 <S2>{RGX_INT}	|
346 <S3>{RGX_INT}	{
347 			char *p;
348 
349 			errno = 0;
350 			yylval.l_int = strtoull(yytext, &p, 0);
351 			yyintprefix = 0;
352 			(void) strncpy(yyintsuffix, p, sizeof (yyintsuffix));
353 			yyintdecimal = yytext[0] != '0';
354 
355 			if (errno == ERANGE) {
356 				xyerror(D_INT_OFLOW, "constant %s results in "
357 				    "integer overflow\n", yytext);
358 			}
359 
360 			if (*p != '\0' && strchr("uUlL", *p) == NULL) {
361 				xyerror(D_INT_DIGIT, "constant %s contains "
362 				    "invalid digit %c\n", yytext, *p);
363 			}
364 
365 			if ((YYSTATE) != S3)
366 				return (DT_TOK_INT);
367 
368 			yypragma = dt_node_link(yypragma,
369 			    dt_node_int(yylval.l_int));
370 		}
371 
372 <S0>{RGX_FP}	yyerror("floating-point constants are not permitted\n");
373 
374 <S0>\"{RGX_STR}$ |
375 <S3>\"{RGX_STR}$ xyerror(D_STR_NL, "newline encountered in string literal");
376 
377 <S0>\"{RGX_STR}\" |
378 <S3>\"{RGX_STR}\" {
379 			/*
380 			 * Quoted string -- convert C escape sequences and
381 			 * return the string as a token.
382 			 */
383 			yylval.l_str = strndup(yytext + 1, yyleng - 2);
384 
385 			if (yylval.l_str == NULL)
386 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
387 
388 			(void) stresc2chr(yylval.l_str);
389 			if ((YYSTATE) != S3)
390 				return (DT_TOK_STRING);
391 
392 			yypragma = dt_node_link(yypragma,
393 			    dt_node_string(yylval.l_str));
394 		}
395 
396 <S0>'{RGX_CHR}$	xyerror(D_CHR_NL, "newline encountered in character constant");
397 
398 <S0>'{RGX_CHR}'	{
399 			char *s, *p, *q;
400 			size_t nbytes;
401 
402 			/*
403 			 * Character constant -- convert C escape sequences and
404 			 * return the character as an integer immediate value.
405 			 */
406 			if (yyleng == 2)
407 				xyerror(D_CHR_NULL, "empty character constant");
408 
409 			s = yytext + 1;
410 			yytext[yyleng - 1] = '\0';
411 			nbytes = stresc2chr(s);
412 			yylval.l_int = 0;
413 			yyintprefix = 0;
414 			yyintsuffix[0] = '\0';
415 			yyintdecimal = 1;
416 
417 			if (nbytes > sizeof (yylval.l_int)) {
418 				xyerror(D_CHR_OFLOW, "character constant is "
419 				    "too long");
420 			}
421 #ifdef _LITTLE_ENDIAN
422 			p = ((char *)&yylval.l_int) + nbytes - 1;
423 			for (q = s; nbytes != 0; nbytes--)
424 				*p-- = *q++;
425 #else
426 			bcopy(s, ((char *)&yylval.l_int) +
427 			    sizeof (yylval.l_int) - nbytes, nbytes);
428 #endif
429 			return (DT_TOK_INT);
430 		}
431 
432 <S0>"/*"	|
433 <S2>"/*"	{
434 			yypcb->pcb_cstate = (YYSTATE);
435 			BEGIN(S1);
436 		}
437 
438 <S0>{RGX_INTERP} |
439 <S2>{RGX_INTERP} ;	/* discard any #! lines */
440 
441 <S0>{RGX_CTL}	|
442 <S2>{RGX_CTL}	|
443 <S4>{RGX_CTL}	{
444 			assert(yypragma == NULL);
445 			yypcb->pcb_cstate = (YYSTATE);
446 			BEGIN(S3);
447 		}
448 
449 <S4>.		;	/* discard */
450 <S4>"\n"	;	/* discard */
451 
452 <S0>"/"		{
453 			int c, tok;
454 
455 			/*
456 			 * The use of "/" as the predicate delimiter and as the
457 			 * integer division symbol requires special lookahead
458 			 * to avoid a shift/reduce conflict in the D grammar.
459 			 * We look ahead to the next non-whitespace character.
460 			 * If we encounter EOF, ";", "{", or "/", then this "/"
461 			 * closes the predicate and we return DT_TOK_EPRED.
462 			 * If we encounter anything else, it's DT_TOK_DIV.
463 			 */
464 			while ((c = input()) != 0) {
465 				if (strchr("\f\n\r\t\v ", c) == NULL)
466 					break;
467 			}
468 
469 			if (c == 0 || c == ';' || c == '{' || c == '/') {
470 				if (yypcb->pcb_parens != 0) {
471 					yyerror("closing ) expected in "
472 					    "predicate before /\n");
473 				}
474 				if (yypcb->pcb_brackets != 0) {
475 					yyerror("closing ] expected in "
476 					    "predicate before /\n");
477 				}
478 				tok = DT_TOK_EPRED;
479 			} else
480 				tok = DT_TOK_DIV;
481 
482 			unput(c);
483 			return (tok);
484 		}
485 
486 <S0>"("		{
487 			yypcb->pcb_parens++;
488 			return (DT_TOK_LPAR);
489 		}
490 
491 <S0>")"		{
492 			if (--yypcb->pcb_parens < 0)
493 				yyerror("extra ) in input stream\n");
494 			return (DT_TOK_RPAR);
495 		}
496 
497 <S0>"["		{
498 			yypcb->pcb_brackets++;
499 			return (DT_TOK_LBRAC);
500 		}
501 
502 <S0>"]"		{
503 			if (--yypcb->pcb_brackets < 0)
504 				yyerror("extra ] in input stream\n");
505 			return (DT_TOK_RBRAC);
506 		}
507 
508 <S0>"{"		|
509 <S2>"{"		{
510 			yypcb->pcb_braces++;
511 			return ('{');
512 		}
513 
514 <S0>"}"		{
515 			if (--yypcb->pcb_braces < 0)
516 				yyerror("extra } in input stream\n");
517 			return ('}');
518 		}
519 
520 <S0>"|"		return (DT_TOK_BOR);
521 <S0>"^"		return (DT_TOK_XOR);
522 <S0>"&"		return (DT_TOK_BAND);
523 <S0>"&&"	return (DT_TOK_LAND);
524 <S0>"^^"	return (DT_TOK_LXOR);
525 <S0>"||"	return (DT_TOK_LOR);
526 <S0>"=="	return (DT_TOK_EQU);
527 <S0>"!="	return (DT_TOK_NEQ);
528 <S0>"<"		return (DT_TOK_LT);
529 <S0>"<="	return (DT_TOK_LE);
530 <S0>">"		return (DT_TOK_GT);
531 <S0>">="	return (DT_TOK_GE);
532 <S0>"<<"	return (DT_TOK_LSH);
533 <S0>">>"	return (DT_TOK_RSH);
534 <S0>"+"		return (DT_TOK_ADD);
535 <S0>"-"		return (DT_TOK_SUB);
536 <S0>"*"		return (DT_TOK_MUL);
537 <S0>"%"		return (DT_TOK_MOD);
538 <S0>"~"		return (DT_TOK_BNEG);
539 <S0>"!"		return (DT_TOK_LNEG);
540 <S0>"?"		return (DT_TOK_QUESTION);
541 <S0>":"		return (DT_TOK_COLON);
542 <S0>"."		return (DT_TOK_DOT);
543 <S0>"->"	return (DT_TOK_PTR);
544 <S0>"="		return (DT_TOK_ASGN);
545 <S0>"+="	return (DT_TOK_ADD_EQ);
546 <S0>"-="	return (DT_TOK_SUB_EQ);
547 <S0>"*="	return (DT_TOK_MUL_EQ);
548 <S0>"/="	return (DT_TOK_DIV_EQ);
549 <S0>"%="	return (DT_TOK_MOD_EQ);
550 <S0>"&="	return (DT_TOK_AND_EQ);
551 <S0>"^="	return (DT_TOK_XOR_EQ);
552 <S0>"|="	return (DT_TOK_OR_EQ);
553 <S0>"<<="	return (DT_TOK_LSH_EQ);
554 <S0>">>="	return (DT_TOK_RSH_EQ);
555 <S0>"++"	return (DT_TOK_ADDADD);
556 <S0>"--"	return (DT_TOK_SUBSUB);
557 <S0>"..."	return (DT_TOK_ELLIPSIS);
558 <S0>","		return (DT_TOK_COMMA);
559 <S0>";"		return (';');
560 <S0>{RGX_WS}	; /* discard */
561 <S0>"\\"\n	; /* discard */
562 <S0>.		yyerror("syntax error near \"%c\"\n", yytext[0]);
563 
564 <S1>"/*"	yyerror("/* encountered inside a comment\n");
565 <S1>"*/"	BEGIN(yypcb->pcb_cstate);
566 <S1>.|\n	; /* discard */
567 
568 <S2>{RGX_PSPEC}	{
569 			/*
570 			 * S2 has an ambiguity because RGX_PSPEC includes '*'
571 			 * as a glob character and '*' also can be DT_TOK_STAR.
572 			 * Since lex always matches the longest token, this
573 			 * rule can be matched by an input string like "int*",
574 			 * which could begin a global variable declaration such
575 			 * as "int*x;" or could begin a RGX_PSPEC with globbing
576 			 * such as "int* { trace(timestamp); }".  If C_PSPEC is
577 			 * not set, we must resolve the ambiguity in favor of
578 			 * the type and perform lexer pushback if the fragment
579 			 * before '*' or entire fragment matches a type name.
580 			 * If C_PSPEC is set, we always return a PSPEC token.
581 			 * If C_PSPEC is off, the user can avoid ambiguity by
582 			 * including a ':' delimiter in the specifier, which
583 			 * they should be doing anyway to specify the provider.
584 			 */
585 			if (!(yypcb->pcb_cflags & DTRACE_C_PSPEC) &&
586 			    strchr(yytext, ':') == NULL) {
587 
588 				char *p = strchr(yytext, '*');
589 				char *q = yytext + yyleng - 1;
590 
591 				if (p != NULL && p > yytext)
592 					*p = '\0'; /* prune yytext */
593 
594 				if (dt_type_lookup(yytext, NULL) == 0) {
595 					yylval.l_str = strdup(yytext);
596 
597 					if (yylval.l_str == NULL) {
598 						longjmp(yypcb->pcb_jmpbuf,
599 						    EDT_NOMEM);
600 					}
601 
602 					if (p != NULL && p > yytext) {
603 						for (*p = '*'; q >= p; q--)
604 							unput(*q);
605 					}
606 
607 					yybegin(YYS_EXPR);
608 					return (DT_TOK_TNAME);
609 				}
610 
611 				if (p != NULL && p > yytext)
612 					*p = '*'; /* restore yytext */
613 			}
614 
615 			if ((yylval.l_str = strdup(yytext)) == NULL)
616 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
617 
618 			return (DT_TOK_PSPEC);
619 		}
620 
621 <S2>"/"		return (DT_TOK_DIV);
622 <S2>","		return (DT_TOK_COMMA);
623 
624 <S2>{RGX_WS}	; /* discard */
625 <S2>.		yyerror("syntax error near \"%c\"\n", yytext[0]);
626 
627 <S3>\n		{
628 			dt_pragma(yypragma);
629 			yypragma = NULL;
630 			BEGIN(yypcb->pcb_cstate);
631 		}
632 
633 <S3>[\f\t\v ]+	; /* discard */
634 
635 <S3>[^\f\n\t\v "]+ {
636 			dt_node_t *dnp;
637 
638 			if ((yylval.l_str = strdup(yytext)) == NULL)
639 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
640 
641 			/*
642 			 * We want to call dt_node_ident() here, but we can't
643 			 * because it will expand inlined identifiers, which we
644 			 * don't want to do from #pragma context in order to
645 			 * support pragmas that apply to the ident itself.  We
646 			 * call dt_node_string() and then reset dn_op instead.
647 			 */
648 			dnp = dt_node_string(yylval.l_str);
649 			dnp->dn_kind = DT_NODE_IDENT;
650 			dnp->dn_op = DT_TOK_IDENT;
651 			yypragma = dt_node_link(yypragma, dnp);
652 		}
653 
654 <S3>.		yyerror("syntax error near \"%c\"\n", yytext[0]);
655 
656 %%
657 
658 /*
659  * yybegin provides a wrapper for use from C code around the lex BEGIN() macro.
660  * We use two main states for lexing because probe descriptions use a syntax
661  * that is incompatible with the normal D tokens (e.g. names can contain "-").
662  * yybegin also handles the job of switching between two lists of dt_nodes
663  * as we allocate persistent definitions, like inlines, and transient nodes
664  * that will be freed once we are done parsing the current program file.
665  */
666 void
667 yybegin(yystate_t state)
668 {
669 #ifdef	YYDEBUG
670 	yydebug = _dtrace_debug;
671 #endif
672 	if (yypcb->pcb_yystate == state)
673 		return; /* nothing to do if we're in the state already */
674 
675 	if (yypcb->pcb_yystate == YYS_DEFINE) {
676 		yypcb->pcb_list = yypcb->pcb_hold;
677 		yypcb->pcb_hold = NULL;
678 	}
679 
680 	switch (state) {
681 	case YYS_CLAUSE:
682 		BEGIN(S2);
683 		break;
684 	case YYS_DEFINE:
685 		assert(yypcb->pcb_hold == NULL);
686 		yypcb->pcb_hold = yypcb->pcb_list;
687 		yypcb->pcb_list = NULL;
688 		/*FALLTHRU*/
689 	case YYS_EXPR:
690 		BEGIN(S0);
691 		break;
692 	case YYS_DONE:
693 		break;
694 	case YYS_CONTROL:
695 		BEGIN(S4);
696 		break;
697 	default:
698 		xyerror(D_UNKNOWN, "internal error -- bad yystate %d\n", state);
699 	}
700 
701 	yypcb->pcb_yystate = state;
702 }
703 
704 void
705 yyinit(dt_pcb_t *pcb)
706 {
707 	yypcb = pcb;
708 	yylineno = 1;
709 	yypragma = NULL;
710 	yysptr = yysbuf;
711 }
712 
713 /*
714  * Given a lexeme 's' (typically yytext), set yylval and return an appropriate
715  * token to the parser indicating either an identifier or a typedef name.
716  * User-defined global variables always take precedence over types, but we do
717  * use some heuristics because D programs can look at an ever-changing set of
718  * kernel types and also can implicitly instantiate variables by assignment,
719  * unlike in C.  The code here is ordered carefully as lookups are not cheap.
720  */
721 static int
722 id_or_type(const char *s)
723 {
724 	dtrace_hdl_t *dtp = yypcb->pcb_hdl;
725 	dt_decl_t *ddp = yypcb->pcb_dstack.ds_decl;
726 	int c0, c1, ttok = DT_TOK_TNAME;
727 	dt_ident_t *idp;
728 
729 	if ((s = yylval.l_str = strdup(s)) == NULL)
730 		longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
731 
732 	/*
733 	 * If the lexeme is a global variable or likely identifier or *not* a
734 	 * type_name, then it is an identifier token.
735 	 */
736 	if (dt_idstack_lookup(&yypcb->pcb_globals, s) != NULL ||
737 	    dt_idhash_lookup(yypcb->pcb_idents, s) != NULL ||
738 	    dt_type_lookup(s, NULL) != 0)
739 		return (DT_TOK_IDENT);
740 
741 	/*
742 	 * If we're in the midst of parsing a declaration and a type_specifier
743 	 * has already been shifted, then return DT_TOK_IDENT instead of TNAME.
744 	 * This semantic is necessary to permit valid ISO C code such as:
745 	 *
746 	 * typedef int foo;
747 	 * struct s { foo foo; };
748 	 *
749 	 * without causing shift/reduce conflicts in the direct_declarator part
750 	 * of the grammar.  The result is that we must check for conflicting
751 	 * redeclarations of the same identifier as part of dt_node_decl().
752 	 */
753 	if (ddp != NULL && ddp->dd_name != NULL)
754 		return (DT_TOK_IDENT);
755 
756 	/*
757 	 * If the lexeme is a type name and we are not in a program clause,
758 	 * then always interpret it as a type and return DT_TOK_TNAME.
759 	 */
760 	if ((YYSTATE) != S0)
761 		return (DT_TOK_TNAME);
762 
763 	/*
764 	 * If the lexeme matches a type name but is in a program clause, then
765 	 * it could be a type or it could be an undefined variable.  Peek at
766 	 * the next token to decide.  If we see ++, --, [, or =, we know there
767 	 * might be an assignment that is trying to create a global variable,
768 	 * so we optimistically return DT_TOK_IDENT.  There is no harm in being
769 	 * wrong: a type_name followed by ++, --, [, or = is a syntax error.
770 	 */
771 	while ((c0 = input()) != 0) {
772 		if (strchr("\f\n\r\t\v ", c0) == NULL)
773 			break;
774 	}
775 
776 	switch (c0) {
777 	case '+':
778 	case '-':
779 		if ((c1 = input()) == c0)
780 			ttok = DT_TOK_IDENT;
781 		unput(c1);
782 		break;
783 
784 	case '=':
785 		if ((c1 = input()) != c0)
786 			ttok = DT_TOK_IDENT;
787 		unput(c1);
788 		break;
789 	case '[':
790 		ttok = DT_TOK_IDENT;
791 		break;
792 	}
793 
794 	if (ttok == DT_TOK_IDENT) {
795 		idp = dt_idhash_insert(yypcb->pcb_idents, s, DT_IDENT_SCALAR, 0,
796 		    0, _dtrace_defattr, 0, &dt_idops_thaw, NULL, dtp->dt_gen);
797 
798 		if (idp == NULL)
799 			longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
800 	}
801 
802 	unput(c0);
803 	return (ttok);
804 }
805 
806 static int
807 input(void)
808 {
809 	int c;
810 
811 	if (yysptr > yysbuf)
812 		c = *--yysptr;
813 	else if (yypcb->pcb_fileptr != NULL)
814 		c = fgetc(yypcb->pcb_fileptr);
815 	else if (yypcb->pcb_strptr < yypcb->pcb_string + yypcb->pcb_strlen)
816 		c = *(unsigned char *)(yypcb->pcb_strptr++);
817 	else
818 		c = EOF;
819 
820 	if (c == '\n')
821 		yylineno++;
822 
823 	if (c != EOF)
824 		return (c);
825 
826 	if ((YYSTATE) == S1)
827 		yyerror("end-of-file encountered before matching */\n");
828 
829 	if ((YYSTATE) == S3)
830 		yyerror("end-of-file encountered before end of control line\n");
831 
832 	if (yypcb->pcb_fileptr != NULL && ferror(yypcb->pcb_fileptr))
833 		longjmp(yypcb->pcb_jmpbuf, EDT_FIO);
834 
835 	return (0); /* EOF */
836 }
837 
838 static void
839 unput(int c)
840 {
841 	if (c == '\n')
842 		yylineno--;
843 
844 	*yysptr++ = c;
845 	yytchar = c;
846 }
847