xref: /illumos-gate/usr/src/cmd/mdb/common/mdb/mdb_grammar.y (revision 7df3beae80fb29626950d633c57d859c12563bc8)
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 2006 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  */
27 
28 /*
29  * Copyright (c) 2015, Joyent, Inc.  All rights reserved.
30  */
31 
32 #include <mdb/mdb_types.h>
33 #include <mdb/mdb_debug.h>
34 #include <mdb/mdb_shell.h>
35 #include <mdb/mdb_string.h>
36 #include <mdb/mdb_frame.h>
37 #include <mdb/mdb_lex.h>
38 #include <mdb/mdb_io.h>
39 #include <mdb/mdb_nv.h>
40 #include <mdb/mdb.h>
41 
42 /*
43  * Utility routines to fetch values from the target's virtual address space
44  * and object file, respectively.  These are called from the handlers for
45  * the * /.../ and % /.../ code below.
46  */
47 
48 static void
49 vfetch(void *buf, size_t nbytes, uintptr_t addr)
50 {
51 	if (mdb_tgt_vread(mdb.m_target, buf, nbytes, addr) != nbytes)
52 		yyperror("failed to read from address %p", addr);
53 }
54 
55 static void
56 ffetch(void *buf, size_t nbytes, uintptr_t addr)
57 {
58 	if (mdb_tgt_fread(mdb.m_target, buf, nbytes, addr) != nbytes)
59 		yyperror("failed to read from address %p", addr);
60 }
61 
62 /*
63  * Because we define YYMAXDEPTH as zero below, we have to provide a YYEXPAND()
64  * function to expand our yys and yyv variables.  For simplicity, we currently
65  * define these structures statically; a more complex solution can be defined if
66  * it is ever needed.  If we return 'val', yacc assumes resize has failed.
67  */
68 static int
69 yyexpand(int val)
70 {
71 	return (val ? val : YYMAXDEPTH);
72 }
73 #define	YYEXPAND	yyexpand
74 
75 /*
76  * This will cause the rest of the yacc code to assume that yys and yyv are
77  * pointers, not static arrays.
78  */
79 #undef	YYMAXDEPTH
80 #define	YYMAXDEPTH	0
81 %}
82 
83 %union {
84 	char *l_string;
85 	char l_char;
86 	uintmax_t l_immediate;
87 	mdb_var_t *l_var;
88 	mdb_idcmd_t *l_dcmd;
89 }
90 
91 %token	<l_string>	MDB_TOK_SYMBOL
92 %token	<l_string>	MDB_TOK_STRING
93 %token	<l_char>	MDB_TOK_CHAR
94 %token	<l_immediate>	MDB_TOK_IMMEDIATE
95 %token	<l_dcmd>	MDB_TOK_DCMD
96 %token	<l_var>		MDB_TOK_VAR_REF
97 %token	<l_immediate>	MDB_TOK_LEXPR
98 %token	<l_immediate>	MDB_TOK_REXPR
99 %token	<l_immediate>	MDB_TOK_COR1_DEREF
100 %token	<l_immediate>	MDB_TOK_COR2_DEREF
101 %token	<l_immediate>	MDB_TOK_COR4_DEREF
102 %token	<l_immediate>	MDB_TOK_COR8_DEREF
103 %token	<l_immediate>	MDB_TOK_OBJ1_DEREF
104 %token	<l_immediate>	MDB_TOK_OBJ2_DEREF
105 %token	<l_immediate>	MDB_TOK_OBJ4_DEREF
106 %token	<l_immediate>	MDB_TOK_OBJ8_DEREF
107 
108 %left	'|'
109 %left	'^'
110 %left	'&'
111 %left	MDB_TOK_EQUAL MDB_TOK_NOTEQUAL
112 %left	MDB_TOK_LSHIFT MDB_TOK_RSHIFT
113 %left	'-' '+'
114 %left	'*' '%' '#'
115 
116 %right	MDB_COR_VALUE
117 %right	MDB_OBJ_VALUE
118 %right	MDB_INT_NEGATE
119 %right	MDB_BIT_COMPLEMENT
120 %right	MDB_LOG_NEGATE
121 %right	MDB_VAR_REFERENCE
122 
123 %type	<l_immediate>	expression
124 %type	<l_dcmd>	command
125 
126 %%
127 statement_list:	/* Empty */
128 	|	statement_list statement { return (0); }
129 	;
130 
131 terminator:	'\n'
132 	|	';'
133 
134 statement:	pipeline shell_pipe terminator {
135 			if (!mdb_call(mdb_nv_get_value(mdb.m_dot), 1, 0))
136 				return (0);
137 		}
138 
139 	|	expression pipeline shell_pipe terminator {
140 			if (!mdb_call($1, 1, DCMD_ADDRSPEC))
141 				return (0);
142 		}
143 
144 	|	expression ',' expression pipeline shell_pipe terminator {
145 			if (!mdb_call($1, $3, DCMD_ADDRSPEC | DCMD_LOOP))
146 				return (0);
147 		}
148 
149 	|	',' expression pipeline shell_pipe terminator {
150 			if (!mdb_call(mdb_nv_get_value(mdb.m_dot), $2,
151 			    DCMD_LOOP))
152 				return (0);
153 		}
154 
155 	|	expression terminator {
156 			mdb_frame_t *pfp = mdb_frame_pipe();
157 			/*
158 			 * The handling of naked expressions is slightly tricky:
159 			 * in a string context, we want to just set dot to the
160 			 * expression value.  In a pipe context, we also set
161 			 * dot but need to record the address in the right-
162 			 * hand command's addrv and update any vcbs that are
163 			 * active.  Otherwise, on the command-line, we have to
164 			 * support this as an alias for executing the previous
165 			 * command with the new value of dot.  Sigh.
166 			 */
167 			if (mdb_iob_isastr(mdb.m_in)) {
168 				mdb_nv_set_value(mdb.m_dot, $1);
169 				mdb.m_incr = 0;
170 			} else if (pfp != NULL && pfp->f_pcmd != NULL) {
171 				mdb_addrvec_unshift(&pfp->f_pcmd->c_addrv,
172 				    (uintptr_t)$1);
173 				mdb_vcb_update(pfp, (uintptr_t)$1);
174 				mdb_nv_set_value(mdb.m_dot, $1);
175 			} else {
176 				mdb_list_move(&mdb.m_lastc,
177 				    &mdb.m_frame->f_cmds);
178 				if (!mdb_call($1, 1, DCMD_ADDRSPEC))
179 					return (0);
180 			}
181 		}
182 
183 	|	expression ',' expression shell_pipe terminator {
184 			mdb_list_move(&mdb.m_lastc, &mdb.m_frame->f_cmds);
185 			if (!mdb_call($1, $3, DCMD_ADDRSPEC | DCMD_LOOP))
186 				return (0);
187 		}
188 
189 	|	',' expression shell_pipe terminator {
190 			uintmax_t dot = mdb_dot_incr(",");
191 			mdb_list_move(&mdb.m_lastc, &mdb.m_frame->f_cmds);
192 			if (!mdb_call(dot, $2, DCMD_LOOP))
193 				return (0);
194 		}
195 
196 	|	'!' MDB_TOK_STRING terminator {
197 			if (mdb_iob_isapipe(mdb.m_in))
198 				yyerror("syntax error");
199 			mdb_shell_exec($2);
200 		}
201 
202 	|	terminator {
203 			if ((mdb.m_flags & MDB_FL_REPLAST) &&
204 			    !mdb_iob_isastr(mdb.m_in)) {
205 				uintmax_t dot = mdb_dot_incr("\\n");
206 				/*
207 				 * If a bare terminator is encountered, execute
208 				 * the previous command if -o repeatlast is set
209 				 * and stdin is not an mdb_eval() string.
210 				 */
211 				mdb_list_move(&mdb.m_lastc,
212 				    &mdb.m_frame->f_cmds);
213 				if (!mdb_call(dot, 1, 0))
214 					return (0);
215 			}
216 		}
217 	;
218 
219 pipeline:	pipeline '|' command { mdb_cmd_create($3, &mdb.m_frame->f_argvec); }
220 	|	command { mdb_cmd_create($1, &mdb.m_frame->f_argvec); }
221 	;
222 
223 command:	'?' format_list { $$ = mdb_dcmd_lookup("?"); }
224 	|	'/' format_list	{ $$ = mdb_dcmd_lookup("/"); }
225 	|	'\\' format_list { $$ = mdb_dcmd_lookup("\\"); }
226 	|	'@' format_list { $$ = mdb_dcmd_lookup("@"); }
227 	|	'=' format_list { $$ = mdb_dcmd_lookup("="); }
228 	|	MDB_TOK_DCMD argument_list { $$ = $1; }
229 	|	'$' { $$ = mdb_dcmd_lookup("$?"); }
230 	;
231 
232 shell_pipe:	/* Empty */
233 	|	'!' MDB_TOK_STRING { mdb_shell_pipe($2); }
234 	;
235 
236 format_list:	/* Empty */
237 	|	format_list MDB_TOK_LEXPR expression MDB_TOK_REXPR {
238 			mdb_arg_t arg;
239 
240 			arg.a_type = MDB_TYPE_IMMEDIATE;
241 			arg.a_un.a_val = $3;
242 
243 			mdb_argvec_append(&mdb.m_frame->f_argvec, &arg);
244 		}
245 
246 	|	format_list MDB_TOK_IMMEDIATE {
247 			mdb_arg_t arg;
248 
249 			arg.a_type = MDB_TYPE_IMMEDIATE;
250 			arg.a_un.a_val = $2;
251 
252 			mdb_argvec_append(&mdb.m_frame->f_argvec, &arg);
253 		}
254 
255 	|	format_list MDB_TOK_STRING	{
256 			mdb_arg_t arg;
257 
258 			arg.a_type = MDB_TYPE_STRING;
259 			arg.a_un.a_str = $2;
260 
261 			mdb_argvec_append(&mdb.m_frame->f_argvec, &arg);
262 		}
263 
264 	|	format_list MDB_TOK_CHAR	{
265 			mdb_arg_t arg;
266 
267 			arg.a_type = MDB_TYPE_CHAR;
268 			arg.a_un.a_char = $2;
269 
270 			mdb_argvec_append(&mdb.m_frame->f_argvec, &arg);
271 		}
272 	;
273 
274 argument_list:	/* Empty */
275 	|	argument_list MDB_TOK_LEXPR expression MDB_TOK_REXPR {
276 			mdb_arg_t arg;
277 
278 			arg.a_type = MDB_TYPE_IMMEDIATE;
279 			arg.a_un.a_val = $3;
280 
281 			mdb_argvec_append(&mdb.m_frame->f_argvec, &arg);
282 		}
283 
284 	|	argument_list MDB_TOK_STRING {
285 			mdb_arg_t arg;
286 
287 			arg.a_type = MDB_TYPE_STRING;
288 			arg.a_un.a_str = $2;
289 
290 			mdb_argvec_append(&mdb.m_frame->f_argvec, &arg);
291 		}
292 	;
293 
294 expression:	expression '+' expression { $$ = $1 + $3; }
295 	|	expression '-' expression { $$ = $1 - $3; }
296 	|	expression '*' expression { $$ = $1 * $3; }
297 
298 	|	expression '%' expression {
299 			if ($3 == 0UL)
300 				yyerror("attempted to divide by zero");
301 
302 			/*
303 			 * Annoyingly, x86 generates a #DE when dividing
304 			 * LONG_MIN by -1; check for this case explicitly.
305 			 */
306 			if ($1 == LONG_MIN && $3 == -1L)
307 				yyerror("divide overflow");
308 
309 			$$ = (intmax_t)$1 / (intmax_t)$3;
310 		}
311 
312 	|	expression '&' expression { $$ = $1 & $3; }
313 	|	expression '|' expression { $$ = $1 | $3; }
314 	|	expression '^' expression { $$ = $1 ^ $3; }
315 
316 	|	expression MDB_TOK_EQUAL expression { $$ = ($1 == $3); }
317 	|	expression MDB_TOK_NOTEQUAL expression { $$ = ($1 != $3); }
318 
319 	|	expression MDB_TOK_LSHIFT expression { $$ = $1 << $3; }
320 	|	expression MDB_TOK_RSHIFT expression { $$ = $1 >> $3; }
321 
322 	|	expression '#' expression {
323 			if ($3 == 0UL)
324 				yyerror("attempted to divide by zero");
325 
326 			$$ = ((intptr_t)($1 + ($3 - 1)) / (intptr_t)$3) * $3;
327 		}
328 
329 	|	'*' expression %prec MDB_COR_VALUE {
330 			uintptr_t value;
331 
332 			vfetch(&value, sizeof (value), $2);
333 			$$ = value;
334 		}
335 
336 	|	MDB_TOK_COR1_DEREF expression %prec MDB_COR_VALUE {
337 			uint8_t value;
338 
339 			vfetch(&value, sizeof (value), $2);
340 			$$ = value;
341 		}
342 
343 	|	MDB_TOK_COR2_DEREF expression %prec MDB_COR_VALUE {
344 			uint16_t value;
345 
346 			vfetch(&value, sizeof (value), $2);
347 			$$ = value;
348 		}
349 
350 	|	MDB_TOK_COR4_DEREF expression %prec MDB_COR_VALUE {
351 			uint32_t value;
352 
353 			vfetch(&value, sizeof (value), $2);
354 			$$ = value;
355 		}
356 
357 	|	MDB_TOK_COR8_DEREF expression %prec MDB_COR_VALUE {
358 			uint64_t value;
359 
360 			vfetch(&value, sizeof (value), $2);
361 			$$ = value;
362 		}
363 
364 	|	'%' expression %prec MDB_OBJ_VALUE {
365 			uintptr_t value;
366 
367 			ffetch(&value, sizeof (value), $2);
368 			$$ = value;
369 		}
370 
371 	|	MDB_TOK_OBJ1_DEREF expression %prec MDB_OBJ_VALUE {
372 			uint8_t value;
373 
374 			ffetch(&value, sizeof (value), $2);
375 			$$ = value;
376 		}
377 
378 	|	MDB_TOK_OBJ2_DEREF expression %prec MDB_OBJ_VALUE {
379 			uint16_t value;
380 
381 			ffetch(&value, sizeof (value), $2);
382 			$$ = value;
383 		}
384 
385 	|	MDB_TOK_OBJ4_DEREF expression %prec MDB_OBJ_VALUE {
386 			uint32_t value;
387 
388 			ffetch(&value, sizeof (value), $2);
389 			$$ = value;
390 		}
391 
392 	|	MDB_TOK_OBJ8_DEREF expression %prec MDB_OBJ_VALUE {
393 			uint64_t value;
394 
395 			ffetch(&value, sizeof (value), $2);
396 			$$ = value;
397 		}
398 
399 	|	'-' expression %prec MDB_INT_NEGATE { $$ = -$2; }
400 	|	'~' expression %prec MDB_BIT_COMPLEMENT { $$ = ~$2; }
401 	|	'#' expression %prec MDB_LOG_NEGATE { $$ = !$2; }
402 	|	'(' expression ')' { $$ = $2; }
403 
404 	|	MDB_TOK_VAR_REF %prec MDB_VAR_REFERENCE {
405 			$$ = mdb_nv_get_value($1);
406 		}
407 
408 	|	MDB_TOK_SYMBOL {
409 			if (strcmp($1, ".") == 0) {
410 				$$ = mdb_nv_get_value(mdb.m_dot);
411 				strfree($1);
412 
413 			} else {
414 				const char *obj = MDB_TGT_OBJ_EVERY, *name = $1;
415 				char *s = (char *)$1;
416 				GElf_Sym sym;
417 
418 				if ((s = strrsplit(s, '`')) != NULL) {
419 					name = s;
420 					obj = $1;
421 				}
422 
423 				if (mdb_tgt_lookup_by_name(mdb.m_target,
424 				    obj, name, &sym, NULL) == -1) {
425 					strfree($1);
426 					yyperror("failed to dereference "
427 					    "symbol");
428 				}
429 
430 				strfree($1);
431 				$$ = (uintmax_t)sym.st_value;
432 			}
433 		}
434 
435 	|	'+' { $$ = mdb_dot_incr("+"); }
436 	|	'^' { $$ = mdb_dot_decr("^"); }
437 	|	'&' { $$ = mdb.m_raddr; }
438 	|	MDB_TOK_IMMEDIATE
439 	;
440 
441 %%
442