xref: /freebsd/cddl/contrib/opensolaris/lib/libdtrace/common/dt_lex.l (revision e9bc68ba9c0dd1ea63a6a2af9c52fbd78dadacb9)
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 #endif
64 
65 static int id_or_type(const char *);
66 #if defined(sun)
67 static int input(void);
68 static void unput(int);
69 #endif
70 
71 /*
72  * We first define a set of labeled states for use in the D lexer and then a
73  * set of regular expressions to simplify things below. The lexer states are:
74  *
75  * S0 - D program clause and expression lexing
76  * S1 - D comments (i.e. skip everything until end of comment)
77  * S2 - D program outer scope (probe specifiers and declarations)
78  * S3 - D control line parsing (i.e. after ^# is seen but before \n)
79  * S4 - D control line scan (locate control directives only and invoke S3)
80  */
81 %}
82 
83 %e 1500		/* maximum nodes */
84 %p 3700		/* maximum positions */
85 %n 600		/* maximum states */
86 
87 %s S0 S1 S2 S3 S4
88 
89 RGX_AGG		"@"[a-zA-Z_][0-9a-zA-Z_]*
90 RGX_PSPEC	[-$:a-zA-Z_.?*\\\[\]!][-$:0-9a-zA-Z_.`?*\\\[\]!]*
91 RGX_IDENT	[a-zA-Z_`][0-9a-zA-Z_`]*
92 RGX_INT		([0-9]+|0[xX][0-9A-Fa-f]+)[uU]?[lL]?[lL]?
93 RGX_FP		([0-9]+("."?)[0-9]*|"."[0-9]+)((e|E)("+"|-)?[0-9]+)?[fFlL]?
94 RGX_WS		[\f\n\r\t\v ]
95 RGX_STR		([^"\\\n]|\\[^"\n]|\\\")*
96 RGX_CHR		([^'\\\n]|\\[^'\n]|\\')*
97 RGX_INTERP	^[\f\t\v ]*#!.*
98 RGX_CTL		^[\f\t\v ]*#
99 
100 %%
101 
102 %{
103 
104 /*
105  * We insert a special prologue into yylex() itself: if the pcb contains a
106  * context token, we return that prior to running the normal lexer.  This
107  * allows libdtrace to force yacc into one of our three parsing contexts: D
108  * expression (DT_CTX_DEXPR), D program (DT_CTX_DPROG) or D type (DT_CTX_DTYPE).
109  * Once the token is returned, we clear it so this only happens once.
110  */
111 if (yypcb->pcb_token != 0) {
112 	int tok = yypcb->pcb_token;
113 	yypcb->pcb_token = 0;
114 	return (tok);
115 }
116 
117 %}
118 
119 <S0>auto	return (DT_KEY_AUTO);
120 <S0>break	return (DT_KEY_BREAK);
121 <S0>case	return (DT_KEY_CASE);
122 <S0>char	return (DT_KEY_CHAR);
123 <S0>const	return (DT_KEY_CONST);
124 <S0>continue	return (DT_KEY_CONTINUE);
125 <S0>counter	return (DT_KEY_COUNTER);
126 <S0>default	return (DT_KEY_DEFAULT);
127 <S0>do		return (DT_KEY_DO);
128 <S0>double	return (DT_KEY_DOUBLE);
129 <S0>else	return (DT_KEY_ELSE);
130 <S0>enum	return (DT_KEY_ENUM);
131 <S0>extern	return (DT_KEY_EXTERN);
132 <S0>float	return (DT_KEY_FLOAT);
133 <S0>for		return (DT_KEY_FOR);
134 <S0>goto	return (DT_KEY_GOTO);
135 <S0>if		return (DT_KEY_IF);
136 <S0>import	return (DT_KEY_IMPORT);
137 <S0>inline	return (DT_KEY_INLINE);
138 <S0>int		return (DT_KEY_INT);
139 <S0>long	return (DT_KEY_LONG);
140 <S0>offsetof	return (DT_TOK_OFFSETOF);
141 <S0>probe	return (DT_KEY_PROBE);
142 <S0>provider	return (DT_KEY_PROVIDER);
143 <S0>register	return (DT_KEY_REGISTER);
144 <S0>restrict	return (DT_KEY_RESTRICT);
145 <S0>return	return (DT_KEY_RETURN);
146 <S0>self	return (DT_KEY_SELF);
147 <S0>short	return (DT_KEY_SHORT);
148 <S0>signed	return (DT_KEY_SIGNED);
149 <S0>sizeof	return (DT_TOK_SIZEOF);
150 <S0>static	return (DT_KEY_STATIC);
151 <S0>string	return (DT_KEY_STRING);
152 <S0>stringof	return (DT_TOK_STRINGOF);
153 <S0>struct	return (DT_KEY_STRUCT);
154 <S0>switch	return (DT_KEY_SWITCH);
155 <S0>this	return (DT_KEY_THIS);
156 <S0>translator	return (DT_KEY_XLATOR);
157 <S0>typedef	return (DT_KEY_TYPEDEF);
158 <S0>union	return (DT_KEY_UNION);
159 <S0>unsigned	return (DT_KEY_UNSIGNED);
160 <S0>void	return (DT_KEY_VOID);
161 <S0>volatile	return (DT_KEY_VOLATILE);
162 <S0>while	return (DT_KEY_WHILE);
163 <S0>xlate	return (DT_TOK_XLATE);
164 
165 <S2>auto	{ yybegin(YYS_EXPR);	return (DT_KEY_AUTO); }
166 <S2>char	{ yybegin(YYS_EXPR);	return (DT_KEY_CHAR); }
167 <S2>const	{ yybegin(YYS_EXPR);	return (DT_KEY_CONST); }
168 <S2>counter	{ yybegin(YYS_DEFINE);	return (DT_KEY_COUNTER); }
169 <S2>double	{ yybegin(YYS_EXPR);	return (DT_KEY_DOUBLE); }
170 <S2>enum	{ yybegin(YYS_EXPR);	return (DT_KEY_ENUM); }
171 <S2>extern	{ yybegin(YYS_EXPR);	return (DT_KEY_EXTERN); }
172 <S2>float	{ yybegin(YYS_EXPR);	return (DT_KEY_FLOAT); }
173 <S2>import	{ yybegin(YYS_EXPR);	return (DT_KEY_IMPORT); }
174 <S2>inline	{ yybegin(YYS_DEFINE);	return (DT_KEY_INLINE); }
175 <S2>int		{ yybegin(YYS_EXPR);	return (DT_KEY_INT); }
176 <S2>long	{ yybegin(YYS_EXPR);	return (DT_KEY_LONG); }
177 <S2>provider	{ yybegin(YYS_DEFINE);	return (DT_KEY_PROVIDER); }
178 <S2>register	{ yybegin(YYS_EXPR);	return (DT_KEY_REGISTER); }
179 <S2>restrict	{ yybegin(YYS_EXPR);	return (DT_KEY_RESTRICT); }
180 <S2>self	{ yybegin(YYS_EXPR);	return (DT_KEY_SELF); }
181 <S2>short	{ yybegin(YYS_EXPR);	return (DT_KEY_SHORT); }
182 <S2>signed	{ yybegin(YYS_EXPR);	return (DT_KEY_SIGNED); }
183 <S2>static	{ yybegin(YYS_EXPR);	return (DT_KEY_STATIC); }
184 <S2>string	{ yybegin(YYS_EXPR);	return (DT_KEY_STRING); }
185 <S2>struct	{ yybegin(YYS_EXPR);	return (DT_KEY_STRUCT); }
186 <S2>this	{ yybegin(YYS_EXPR);	return (DT_KEY_THIS); }
187 <S2>translator	{ yybegin(YYS_DEFINE);	return (DT_KEY_XLATOR); }
188 <S2>typedef	{ yybegin(YYS_EXPR);	return (DT_KEY_TYPEDEF); }
189 <S2>union	{ yybegin(YYS_EXPR);	return (DT_KEY_UNION); }
190 <S2>unsigned	{ yybegin(YYS_EXPR);	return (DT_KEY_UNSIGNED); }
191 <S2>void	{ yybegin(YYS_EXPR);	return (DT_KEY_VOID); }
192 <S2>volatile	{ yybegin(YYS_EXPR);	return (DT_KEY_VOLATILE); }
193 
194 <S0>"$$"[0-9]+	{
195 			int i = atoi(yytext + 2);
196 			char *v = "";
197 
198 			/*
199 			 * A macro argument reference substitutes the text of
200 			 * an argument in place of the current token.  When we
201 			 * see $$<d> we fetch the saved string from pcb_sargv
202 			 * (or use the default argument if the option has been
203 			 * set and the argument hasn't been specified) and
204 			 * return a token corresponding to this string.
205 			 */
206 			if (i < 0 || (i >= yypcb->pcb_sargc &&
207 			    !(yypcb->pcb_cflags & DTRACE_C_DEFARG))) {
208 				xyerror(D_MACRO_UNDEF, "macro argument %s is "
209 				    "not defined\n", yytext);
210 			}
211 
212 			if (i < yypcb->pcb_sargc) {
213 				v = yypcb->pcb_sargv[i]; /* get val from pcb */
214 				yypcb->pcb_sflagv[i] |= DT_IDFLG_REF;
215 			}
216 
217 			if ((yylval.l_str = strdup(v)) == NULL)
218 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
219 
220 			(void) stresc2chr(yylval.l_str);
221 			return (DT_TOK_STRING);
222 		}
223 
224 <S0>"$"[0-9]+	{
225 			int i = atoi(yytext + 1);
226 			char *p, *v = "0";
227 
228 			/*
229 			 * A macro argument reference substitutes the text of
230 			 * one identifier or integer pattern for another.  When
231 			 * we see $<d> we fetch the saved string from pcb_sargv
232 			 * (or use the default argument if the option has been
233 			 * set and the argument hasn't been specified) and
234 			 * return a token corresponding to this string.
235 			 */
236 			if (i < 0 || (i >= yypcb->pcb_sargc &&
237 			    !(yypcb->pcb_cflags & DTRACE_C_DEFARG))) {
238 				xyerror(D_MACRO_UNDEF, "macro argument %s is "
239 				    "not defined\n", yytext);
240 			}
241 
242 			if (i < yypcb->pcb_sargc) {
243 				v = yypcb->pcb_sargv[i]; /* get val from pcb */
244 				yypcb->pcb_sflagv[i] |= DT_IDFLG_REF;
245 			}
246 
247 			/*
248 			 * If the macro text is not a valid integer or ident,
249 			 * then we treat it as a string.  The string may be
250 			 * optionally enclosed in quotes, which we strip.
251 			 */
252 			if (strbadidnum(v)) {
253 				size_t len = strlen(v);
254 
255 				if (len != 1 && *v == '"' && v[len - 1] == '"')
256 					yylval.l_str = strndup(v + 1, len - 2);
257 				else
258 					yylval.l_str = strndup(v, len);
259 
260 				if (yylval.l_str == NULL)
261 					longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
262 
263 				(void) stresc2chr(yylval.l_str);
264 				return (DT_TOK_STRING);
265 			}
266 
267 			/*
268 			 * If the macro text is not a string an begins with a
269 			 * digit or a +/- sign, process it as an integer token.
270 			 */
271 			if (isdigit(v[0]) || v[0] == '-' || v[0] == '+') {
272 				if (isdigit(v[0]))
273 					yyintprefix = 0;
274 				else
275 					yyintprefix = *v++;
276 
277 				errno = 0;
278 				yylval.l_int = strtoull(v, &p, 0);
279 				(void) strncpy(yyintsuffix, p,
280 				    sizeof (yyintsuffix));
281 				yyintdecimal = *v != '0';
282 
283 				if (errno == ERANGE) {
284 					xyerror(D_MACRO_OFLOW, "macro argument"
285 					    " %s constant %s results in integer"
286 					    " overflow\n", yytext, v);
287 				}
288 
289 				return (DT_TOK_INT);
290 			}
291 
292 			return (id_or_type(v));
293 		}
294 
295 <S0>"$$"{RGX_IDENT} {
296 			dt_ident_t *idp = dt_idhash_lookup(
297 			    yypcb->pcb_hdl->dt_macros, yytext + 2);
298 
299 			char s[16]; /* enough for UINT_MAX + \0 */
300 
301 			if (idp == NULL) {
302 				xyerror(D_MACRO_UNDEF, "macro variable %s "
303 				    "is not defined\n", yytext);
304 			}
305 
306 			/*
307 			 * For the moment, all current macro variables are of
308 			 * type id_t (refer to dtrace_update() for details).
309 			 */
310 			(void) snprintf(s, sizeof (s), "%u", idp->di_id);
311 			if ((yylval.l_str = strdup(s)) == NULL)
312 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
313 
314 			return (DT_TOK_STRING);
315 		}
316 
317 <S0>"$"{RGX_IDENT} {
318 			dt_ident_t *idp = dt_idhash_lookup(
319 			    yypcb->pcb_hdl->dt_macros, yytext + 1);
320 
321 			if (idp == NULL) {
322 				xyerror(D_MACRO_UNDEF, "macro variable %s "
323 				    "is not defined\n", yytext);
324 			}
325 
326 			/*
327 			 * For the moment, all current macro variables are of
328 			 * type id_t (refer to dtrace_update() for details).
329 			 */
330 			yylval.l_int = (intmax_t)(int)idp->di_id;
331 			yyintprefix = 0;
332 			yyintsuffix[0] = '\0';
333 			yyintdecimal = 1;
334 
335 			return (DT_TOK_INT);
336 		}
337 
338 <S0>{RGX_IDENT}	{
339 			return (id_or_type(yytext));
340 		}
341 
342 <S0>{RGX_AGG}	{
343 			if ((yylval.l_str = strdup(yytext)) == NULL)
344 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
345 			return (DT_TOK_AGG);
346 		}
347 
348 <S0>"@"		{
349 			if ((yylval.l_str = strdup("@_")) == NULL)
350 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
351 			return (DT_TOK_AGG);
352 		}
353 
354 <S0>{RGX_INT}	|
355 <S2>{RGX_INT}	|
356 <S3>{RGX_INT}	{
357 			char *p;
358 
359 			errno = 0;
360 			yylval.l_int = strtoull(yytext, &p, 0);
361 			yyintprefix = 0;
362 			(void) strncpy(yyintsuffix, p, sizeof (yyintsuffix));
363 			yyintdecimal = yytext[0] != '0';
364 
365 			if (errno == ERANGE) {
366 				xyerror(D_INT_OFLOW, "constant %s results in "
367 				    "integer overflow\n", yytext);
368 			}
369 
370 			if (*p != '\0' && strchr("uUlL", *p) == NULL) {
371 				xyerror(D_INT_DIGIT, "constant %s contains "
372 				    "invalid digit %c\n", yytext, *p);
373 			}
374 
375 			if ((YYSTATE) != S3)
376 				return (DT_TOK_INT);
377 
378 			yypragma = dt_node_link(yypragma,
379 			    dt_node_int(yylval.l_int));
380 		}
381 
382 <S0>{RGX_FP}	yyerror("floating-point constants are not permitted\n");
383 
384 <S0>\"{RGX_STR}$ |
385 <S3>\"{RGX_STR}$ xyerror(D_STR_NL, "newline encountered in string literal");
386 
387 <S0>\"{RGX_STR}\" |
388 <S3>\"{RGX_STR}\" {
389 			/*
390 			 * Quoted string -- convert C escape sequences and
391 			 * return the string as a token.
392 			 */
393 			yylval.l_str = strndup(yytext + 1, yyleng - 2);
394 
395 			if (yylval.l_str == NULL)
396 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
397 
398 			(void) stresc2chr(yylval.l_str);
399 			if ((YYSTATE) != S3)
400 				return (DT_TOK_STRING);
401 
402 			yypragma = dt_node_link(yypragma,
403 			    dt_node_string(yylval.l_str));
404 		}
405 
406 <S0>'{RGX_CHR}$	xyerror(D_CHR_NL, "newline encountered in character constant");
407 
408 <S0>'{RGX_CHR}'	{
409 			char *s, *p, *q;
410 			size_t nbytes;
411 
412 			/*
413 			 * Character constant -- convert C escape sequences and
414 			 * return the character as an integer immediate value.
415 			 */
416 			if (yyleng == 2)
417 				xyerror(D_CHR_NULL, "empty character constant");
418 
419 			s = yytext + 1;
420 			yytext[yyleng - 1] = '\0';
421 			nbytes = stresc2chr(s);
422 			yylval.l_int = 0;
423 			yyintprefix = 0;
424 			yyintsuffix[0] = '\0';
425 			yyintdecimal = 1;
426 
427 			if (nbytes > sizeof (yylval.l_int)) {
428 				xyerror(D_CHR_OFLOW, "character constant is "
429 				    "too long");
430 			}
431 #if BYTE_ORDER == _LITTLE_ENDIAN
432 			p = ((char *)&yylval.l_int) + nbytes - 1;
433 			for (q = s; nbytes != 0; nbytes--)
434 				*p-- = *q++;
435 #else
436 			bcopy(s, ((char *)&yylval.l_int) +
437 			    sizeof (yylval.l_int) - nbytes, nbytes);
438 #endif
439 			return (DT_TOK_INT);
440 		}
441 
442 <S0>"/*"	|
443 <S2>"/*"	{
444 			yypcb->pcb_cstate = (YYSTATE);
445 			BEGIN(S1);
446 		}
447 
448 <S0>{RGX_INTERP} |
449 <S2>{RGX_INTERP} ;	/* discard any #! lines */
450 
451 <S0>{RGX_CTL}	|
452 <S2>{RGX_CTL}	|
453 <S4>{RGX_CTL}	{
454 			assert(yypragma == NULL);
455 			yypcb->pcb_cstate = (YYSTATE);
456 			BEGIN(S3);
457 		}
458 
459 <S4>.		;	/* discard */
460 <S4>"\n"	;	/* discard */
461 
462 <S0>"/"		{
463 			int c, tok;
464 
465 			/*
466 			 * The use of "/" as the predicate delimiter and as the
467 			 * integer division symbol requires special lookahead
468 			 * to avoid a shift/reduce conflict in the D grammar.
469 			 * We look ahead to the next non-whitespace character.
470 			 * If we encounter EOF, ";", "{", or "/", then this "/"
471 			 * closes the predicate and we return DT_TOK_EPRED.
472 			 * If we encounter anything else, it's DT_TOK_DIV.
473 			 */
474 			while ((c = input()) != 0) {
475 				if (strchr("\f\n\r\t\v ", c) == NULL)
476 					break;
477 			}
478 
479 			if (c == 0 || c == ';' || c == '{' || c == '/') {
480 				if (yypcb->pcb_parens != 0) {
481 					yyerror("closing ) expected in "
482 					    "predicate before /\n");
483 				}
484 				if (yypcb->pcb_brackets != 0) {
485 					yyerror("closing ] expected in "
486 					    "predicate before /\n");
487 				}
488 				tok = DT_TOK_EPRED;
489 			} else
490 				tok = DT_TOK_DIV;
491 
492 			unput(c);
493 			return (tok);
494 		}
495 
496 <S0>"("		{
497 			yypcb->pcb_parens++;
498 			return (DT_TOK_LPAR);
499 		}
500 
501 <S0>")"		{
502 			if (--yypcb->pcb_parens < 0)
503 				yyerror("extra ) in input stream\n");
504 			return (DT_TOK_RPAR);
505 		}
506 
507 <S0>"["		{
508 			yypcb->pcb_brackets++;
509 			return (DT_TOK_LBRAC);
510 		}
511 
512 <S0>"]"		{
513 			if (--yypcb->pcb_brackets < 0)
514 				yyerror("extra ] in input stream\n");
515 			return (DT_TOK_RBRAC);
516 		}
517 
518 <S0>"{"		|
519 <S2>"{"		{
520 			yypcb->pcb_braces++;
521 			return ('{');
522 		}
523 
524 <S0>"}"		{
525 			if (--yypcb->pcb_braces < 0)
526 				yyerror("extra } in input stream\n");
527 			return ('}');
528 		}
529 
530 <S0>"|"		return (DT_TOK_BOR);
531 <S0>"^"		return (DT_TOK_XOR);
532 <S0>"&"		return (DT_TOK_BAND);
533 <S0>"&&"	return (DT_TOK_LAND);
534 <S0>"^^"	return (DT_TOK_LXOR);
535 <S0>"||"	return (DT_TOK_LOR);
536 <S0>"=="	return (DT_TOK_EQU);
537 <S0>"!="	return (DT_TOK_NEQ);
538 <S0>"<"		return (DT_TOK_LT);
539 <S0>"<="	return (DT_TOK_LE);
540 <S0>">"		return (DT_TOK_GT);
541 <S0>">="	return (DT_TOK_GE);
542 <S0>"<<"	return (DT_TOK_LSH);
543 <S0>">>"	return (DT_TOK_RSH);
544 <S0>"+"		return (DT_TOK_ADD);
545 <S0>"-"		return (DT_TOK_SUB);
546 <S0>"*"		return (DT_TOK_MUL);
547 <S0>"%"		return (DT_TOK_MOD);
548 <S0>"~"		return (DT_TOK_BNEG);
549 <S0>"!"		return (DT_TOK_LNEG);
550 <S0>"?"		return (DT_TOK_QUESTION);
551 <S0>":"		return (DT_TOK_COLON);
552 <S0>"."		return (DT_TOK_DOT);
553 <S0>"->"	return (DT_TOK_PTR);
554 <S0>"="		return (DT_TOK_ASGN);
555 <S0>"+="	return (DT_TOK_ADD_EQ);
556 <S0>"-="	return (DT_TOK_SUB_EQ);
557 <S0>"*="	return (DT_TOK_MUL_EQ);
558 <S0>"/="	return (DT_TOK_DIV_EQ);
559 <S0>"%="	return (DT_TOK_MOD_EQ);
560 <S0>"&="	return (DT_TOK_AND_EQ);
561 <S0>"^="	return (DT_TOK_XOR_EQ);
562 <S0>"|="	return (DT_TOK_OR_EQ);
563 <S0>"<<="	return (DT_TOK_LSH_EQ);
564 <S0>">>="	return (DT_TOK_RSH_EQ);
565 <S0>"++"	return (DT_TOK_ADDADD);
566 <S0>"--"	return (DT_TOK_SUBSUB);
567 <S0>"..."	return (DT_TOK_ELLIPSIS);
568 <S0>","		return (DT_TOK_COMMA);
569 <S0>";"		return (';');
570 <S0>{RGX_WS}	; /* discard */
571 <S0>"\\"\n	; /* discard */
572 <S0>.		yyerror("syntax error near \"%c\"\n", yytext[0]);
573 
574 <S1>"/*"	yyerror("/* encountered inside a comment\n");
575 <S1>"*/"	BEGIN(yypcb->pcb_cstate);
576 <S1>.|\n	; /* discard */
577 
578 <S2>{RGX_PSPEC}	{
579 			/*
580 			 * S2 has an ambiguity because RGX_PSPEC includes '*'
581 			 * as a glob character and '*' also can be DT_TOK_STAR.
582 			 * Since lex always matches the longest token, this
583 			 * rule can be matched by an input string like "int*",
584 			 * which could begin a global variable declaration such
585 			 * as "int*x;" or could begin a RGX_PSPEC with globbing
586 			 * such as "int* { trace(timestamp); }".  If C_PSPEC is
587 			 * not set, we must resolve the ambiguity in favor of
588 			 * the type and perform lexer pushback if the fragment
589 			 * before '*' or entire fragment matches a type name.
590 			 * If C_PSPEC is set, we always return a PSPEC token.
591 			 * If C_PSPEC is off, the user can avoid ambiguity by
592 			 * including a ':' delimiter in the specifier, which
593 			 * they should be doing anyway to specify the provider.
594 			 */
595 			if (!(yypcb->pcb_cflags & DTRACE_C_PSPEC) &&
596 			    strchr(yytext, ':') == NULL) {
597 
598 				char *p = strchr(yytext, '*');
599 				char *q = yytext + yyleng - 1;
600 
601 				if (p != NULL && p > yytext)
602 					*p = '\0'; /* prune yytext */
603 
604 				if (dt_type_lookup(yytext, NULL) == 0) {
605 					yylval.l_str = strdup(yytext);
606 
607 					if (yylval.l_str == NULL) {
608 						longjmp(yypcb->pcb_jmpbuf,
609 						    EDT_NOMEM);
610 					}
611 
612 					if (p != NULL && p > yytext) {
613 						for (*p = '*'; q >= p; q--)
614 							unput(*q);
615 					}
616 
617 					yybegin(YYS_EXPR);
618 					return (DT_TOK_TNAME);
619 				}
620 
621 				if (p != NULL && p > yytext)
622 					*p = '*'; /* restore yytext */
623 			}
624 
625 			if ((yylval.l_str = strdup(yytext)) == NULL)
626 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
627 
628 			return (DT_TOK_PSPEC);
629 		}
630 
631 <S2>"/"		return (DT_TOK_DIV);
632 <S2>","		return (DT_TOK_COMMA);
633 
634 <S2>{RGX_WS}	; /* discard */
635 <S2>.		yyerror("syntax error near \"%c\"\n", yytext[0]);
636 
637 <S3>\n		{
638 			dt_pragma(yypragma);
639 			yypragma = NULL;
640 			BEGIN(yypcb->pcb_cstate);
641 		}
642 
643 <S3>[\f\t\v ]+	; /* discard */
644 
645 <S3>[^\f\n\t\v "]+ {
646 			dt_node_t *dnp;
647 
648 			if ((yylval.l_str = strdup(yytext)) == NULL)
649 				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
650 
651 			/*
652 			 * We want to call dt_node_ident() here, but we can't
653 			 * because it will expand inlined identifiers, which we
654 			 * don't want to do from #pragma context in order to
655 			 * support pragmas that apply to the ident itself.  We
656 			 * call dt_node_string() and then reset dn_op instead.
657 			 */
658 			dnp = dt_node_string(yylval.l_str);
659 			dnp->dn_kind = DT_NODE_IDENT;
660 			dnp->dn_op = DT_TOK_IDENT;
661 			yypragma = dt_node_link(yypragma, dnp);
662 		}
663 
664 <S3>.		yyerror("syntax error near \"%c\"\n", yytext[0]);
665 
666 %%
667 
668 /*
669  * yybegin provides a wrapper for use from C code around the lex BEGIN() macro.
670  * We use two main states for lexing because probe descriptions use a syntax
671  * that is incompatible with the normal D tokens (e.g. names can contain "-").
672  * yybegin also handles the job of switching between two lists of dt_nodes
673  * as we allocate persistent definitions, like inlines, and transient nodes
674  * that will be freed once we are done parsing the current program file.
675  */
676 void
677 yybegin(yystate_t state)
678 {
679 #ifdef	YYDEBUG
680 	yydebug = _dtrace_debug;
681 #endif
682 	if (yypcb->pcb_yystate == state)
683 		return; /* nothing to do if we're in the state already */
684 
685 	if (yypcb->pcb_yystate == YYS_DEFINE) {
686 		yypcb->pcb_list = yypcb->pcb_hold;
687 		yypcb->pcb_hold = NULL;
688 	}
689 
690 	switch (state) {
691 	case YYS_CLAUSE:
692 		BEGIN(S2);
693 		break;
694 	case YYS_DEFINE:
695 		assert(yypcb->pcb_hold == NULL);
696 		yypcb->pcb_hold = yypcb->pcb_list;
697 		yypcb->pcb_list = NULL;
698 		/*FALLTHRU*/
699 	case YYS_EXPR:
700 		BEGIN(S0);
701 		break;
702 	case YYS_DONE:
703 		break;
704 	case YYS_CONTROL:
705 		BEGIN(S4);
706 		break;
707 	default:
708 		xyerror(D_UNKNOWN, "internal error -- bad yystate %d\n", state);
709 	}
710 
711 	yypcb->pcb_yystate = state;
712 }
713 
714 void
715 yyinit(dt_pcb_t *pcb)
716 {
717 	yypcb = pcb;
718 	yylineno = 1;
719 	yypragma = NULL;
720 #if defined(sun)
721 	yysptr = yysbuf;
722 #endif
723 }
724 
725 /*
726  * Given a lexeme 's' (typically yytext), set yylval and return an appropriate
727  * token to the parser indicating either an identifier or a typedef name.
728  * User-defined global variables always take precedence over types, but we do
729  * use some heuristics because D programs can look at an ever-changing set of
730  * kernel types and also can implicitly instantiate variables by assignment,
731  * unlike in C.  The code here is ordered carefully as lookups are not cheap.
732  */
733 static int
734 id_or_type(const char *s)
735 {
736 	dtrace_hdl_t *dtp = yypcb->pcb_hdl;
737 	dt_decl_t *ddp = yypcb->pcb_dstack.ds_decl;
738 	int c0, c1, ttok = DT_TOK_TNAME;
739 	dt_ident_t *idp;
740 
741 	if ((s = yylval.l_str = strdup(s)) == NULL)
742 		longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
743 
744 	/*
745 	 * If the lexeme is a global variable or likely identifier or *not* a
746 	 * type_name, then it is an identifier token.
747 	 */
748 	if (dt_idstack_lookup(&yypcb->pcb_globals, s) != NULL ||
749 	    dt_idhash_lookup(yypcb->pcb_idents, s) != NULL ||
750 	    dt_type_lookup(s, NULL) != 0)
751 		return (DT_TOK_IDENT);
752 
753 	/*
754 	 * If we're in the midst of parsing a declaration and a type_specifier
755 	 * has already been shifted, then return DT_TOK_IDENT instead of TNAME.
756 	 * This semantic is necessary to permit valid ISO C code such as:
757 	 *
758 	 * typedef int foo;
759 	 * struct s { foo foo; };
760 	 *
761 	 * without causing shift/reduce conflicts in the direct_declarator part
762 	 * of the grammar.  The result is that we must check for conflicting
763 	 * redeclarations of the same identifier as part of dt_node_decl().
764 	 */
765 	if (ddp != NULL && ddp->dd_name != NULL)
766 		return (DT_TOK_IDENT);
767 
768 	/*
769 	 * If the lexeme is a type name and we are not in a program clause,
770 	 * then always interpret it as a type and return DT_TOK_TNAME.
771 	 */
772 	if ((YYSTATE) != S0)
773 		return (DT_TOK_TNAME);
774 
775 	/*
776 	 * If the lexeme matches a type name but is in a program clause, then
777 	 * it could be a type or it could be an undefined variable.  Peek at
778 	 * the next token to decide.  If we see ++, --, [, or =, we know there
779 	 * might be an assignment that is trying to create a global variable,
780 	 * so we optimistically return DT_TOK_IDENT.  There is no harm in being
781 	 * wrong: a type_name followed by ++, --, [, or = is a syntax error.
782 	 */
783 	while ((c0 = input()) != 0) {
784 		if (strchr("\f\n\r\t\v ", c0) == NULL)
785 			break;
786 	}
787 
788 	switch (c0) {
789 	case '+':
790 	case '-':
791 		if ((c1 = input()) == c0)
792 			ttok = DT_TOK_IDENT;
793 		unput(c1);
794 		break;
795 
796 	case '=':
797 		if ((c1 = input()) != c0)
798 			ttok = DT_TOK_IDENT;
799 		unput(c1);
800 		break;
801 	case '[':
802 		ttok = DT_TOK_IDENT;
803 		break;
804 	}
805 
806 	if (ttok == DT_TOK_IDENT) {
807 		idp = dt_idhash_insert(yypcb->pcb_idents, s, DT_IDENT_SCALAR, 0,
808 		    0, _dtrace_defattr, 0, &dt_idops_thaw, NULL, dtp->dt_gen);
809 
810 		if (idp == NULL)
811 			longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
812 	}
813 
814 	if (c0 != EOF)
815 		unput(c0);
816 	return (ttok);
817 }
818 
819 #if defined(sun)
820 static int
821 input(void)
822 {
823 	int c;
824 
825 	if (yysptr > yysbuf)
826 		c = *--yysptr;
827 	else if (yypcb->pcb_fileptr != NULL)
828 		c = fgetc(yypcb->pcb_fileptr);
829 	else if (yypcb->pcb_strptr < yypcb->pcb_string + yypcb->pcb_strlen)
830 		c = *yypcb->pcb_strptr++;
831 	else
832 		c = EOF;
833 
834 	if (c == '\n')
835 		yylineno++;
836 
837 	if (c != EOF)
838 		return (c);
839 
840 	if ((YYSTATE) == S1)
841 		yyerror("end-of-file encountered before matching */\n");
842 
843 	if ((YYSTATE) == S3)
844 		yyerror("end-of-file encountered before end of control line\n");
845 
846 	if (yypcb->pcb_fileptr != NULL && ferror(yypcb->pcb_fileptr))
847 		longjmp(yypcb->pcb_jmpbuf, EDT_FIO);
848 
849 	return (0); /* EOF */
850 }
851 
852 static void
853 unput(int c)
854 {
855 	if (c == '\n')
856 		yylineno--;
857 
858 	*yysptr++ = c;
859 	yytchar = c;
860 }
861 #endif
862