xref: /titanic_44/usr/src/lib/libdtrace/common/dt_xlator.c (revision 3c112a2b34403220c06c3e2fcac403358cfba168)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * 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  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <strings.h>
30 #include <assert.h>
31 
32 #include <dt_xlator.h>
33 #include <dt_parser.h>
34 #include <dt_grammar.h>
35 #include <dt_module.h>
36 #include <dt_impl.h>
37 
38 /*
39  * Create a member node corresponding to one of the output members of a dynamic
40  * translator.  We set the member's dn_membexpr to a DT_NODE_XLATOR node that
41  * has dn_op set to DT_TOK_XLATE and refers back to the translator itself.  The
42  * code generator will then use this as the indicator for dynamic translation.
43  */
44 /*ARGSUSED*/
45 static int
46 dt_xlator_create_member(const char *name, ctf_id_t type, ulong_t off, void *arg)
47 {
48 	dt_xlator_t *dxp = arg;
49 	dtrace_hdl_t *dtp = dxp->dx_hdl;
50 	dt_node_t *enp, *mnp;
51 
52 	if ((enp = dt_node_xalloc(dtp, DT_NODE_XLATOR)) == NULL)
53 		return (dt_set_errno(dtp, EDT_NOMEM));
54 
55 	enp->dn_link = dxp->dx_nodes;
56 	dxp->dx_nodes = enp;
57 
58 	if ((mnp = dt_node_xalloc(dtp, DT_NODE_MEMBER)) == NULL)
59 		return (dt_set_errno(dtp, EDT_NOMEM));
60 
61 	mnp->dn_link = dxp->dx_nodes;
62 	dxp->dx_nodes = mnp;
63 
64 	/*
65 	 * For the member expression, we use a DT_NODE_XLATOR/TOK_XLATE whose
66 	 * xlator refers back to the translator and whose dn_xmember refers to
67 	 * the current member.  These refs will be used by dt_cg.c and dt_as.c.
68 	 */
69 	enp->dn_op = DT_TOK_XLATE;
70 	enp->dn_xlator = dxp;
71 	enp->dn_xmember = mnp;
72 	dt_node_type_assign(enp, dxp->dx_dst_ctfp, type);
73 
74 	/*
75 	 * For the member itself, we use a DT_NODE_MEMBER as usual with the
76 	 * appropriate name, output type, and member expression set to 'enp'.
77 	 */
78 	if (dxp->dx_members != NULL) {
79 		assert(enp->dn_link->dn_kind == DT_NODE_MEMBER);
80 		enp->dn_link->dn_list = mnp;
81 	} else
82 		dxp->dx_members = mnp;
83 
84 	mnp->dn_membname = strdup(name);
85 	mnp->dn_membexpr = enp;
86 	dt_node_type_assign(mnp, dxp->dx_dst_ctfp, type);
87 
88 	if (mnp->dn_membname == NULL)
89 		return (dt_set_errno(dtp, EDT_NOMEM));
90 
91 	return (0);
92 }
93 
94 dt_xlator_t *
95 dt_xlator_create(dtrace_hdl_t *dtp,
96     const dtrace_typeinfo_t *src, const dtrace_typeinfo_t *dst,
97     const char *name, dt_node_t *members, dt_node_t *nodes)
98 {
99 	dt_xlator_t *dxp = dt_zalloc(dtp, sizeof (dt_xlator_t));
100 	dtrace_typeinfo_t ptr = *dst;
101 	dt_xlator_t **map;
102 	dt_node_t *dnp;
103 	uint_t kind;
104 
105 	if (dxp == NULL)
106 		return (NULL);
107 
108 	dxp->dx_hdl = dtp;
109 	dxp->dx_id = dtp->dt_xlatorid++;
110 	dxp->dx_gen = dtp->dt_gen;
111 	dxp->dx_arg = -1;
112 
113 	if ((map = dt_alloc(dtp, sizeof (void *) * (dxp->dx_id + 1))) == NULL) {
114 		dt_free(dtp, dxp);
115 		return (NULL);
116 	}
117 
118 	dt_list_append(&dtp->dt_xlators, dxp);
119 	bcopy(dtp->dt_xlatormap, map, sizeof (void *) * dxp->dx_id);
120 	dt_free(dtp, dtp->dt_xlatormap);
121 	dtp->dt_xlatormap = map;
122 	dtp->dt_xlatormap[dxp->dx_id] = dxp;
123 
124 	if (dt_type_pointer(&ptr) == -1) {
125 		ptr.dtt_ctfp = NULL;
126 		ptr.dtt_type = CTF_ERR;
127 	}
128 
129 	dxp->dx_ident = dt_ident_create(name ? name : "T",
130 	    DT_IDENT_SCALAR, DT_IDFLG_REF | DT_IDFLG_ORPHAN, 0,
131 	    _dtrace_defattr, 0, &dt_idops_thaw, NULL, dtp->dt_gen);
132 
133 	if (dxp->dx_ident == NULL)
134 		goto err; /* no memory for identifier */
135 
136 	dxp->dx_ident->di_ctfp = src->dtt_ctfp;
137 	dxp->dx_ident->di_type = src->dtt_type;
138 
139 	/*
140 	 * If an input parameter name is given, this is a static translator
141 	 * definition: create an idhash and identifier for the parameter.
142 	 */
143 	if (name != NULL) {
144 		dxp->dx_locals = dt_idhash_create("xlparams", NULL, 0, 0);
145 
146 		if (dxp->dx_locals == NULL)
147 			goto err; /* no memory for identifier hash */
148 
149 		dt_idhash_xinsert(dxp->dx_locals, dxp->dx_ident);
150 	}
151 
152 	dxp->dx_souid.di_name = "translator";
153 	dxp->dx_souid.di_kind = DT_IDENT_XLSOU;
154 	dxp->dx_souid.di_flags = DT_IDFLG_REF;
155 	dxp->dx_souid.di_id = dxp->dx_id;
156 	dxp->dx_souid.di_attr = _dtrace_defattr;
157 	dxp->dx_souid.di_ops = &dt_idops_thaw;
158 	dxp->dx_souid.di_data = dxp;
159 	dxp->dx_souid.di_ctfp = dst->dtt_ctfp;
160 	dxp->dx_souid.di_type = dst->dtt_type;
161 	dxp->dx_souid.di_gen = dtp->dt_gen;
162 
163 	dxp->dx_ptrid.di_name = "translator";
164 	dxp->dx_ptrid.di_kind = DT_IDENT_XLPTR;
165 	dxp->dx_ptrid.di_flags = DT_IDFLG_REF;
166 	dxp->dx_ptrid.di_id = dxp->dx_id;
167 	dxp->dx_ptrid.di_attr = _dtrace_defattr;
168 	dxp->dx_ptrid.di_ops = &dt_idops_thaw;
169 	dxp->dx_ptrid.di_data = dxp;
170 	dxp->dx_ptrid.di_ctfp = ptr.dtt_ctfp;
171 	dxp->dx_ptrid.di_type = ptr.dtt_type;
172 	dxp->dx_ptrid.di_gen = dtp->dt_gen;
173 
174 	/*
175 	 * If a deferred pragma is pending on the keyword "translator", run all
176 	 * the deferred pragmas on dx_souid and then copy results to dx_ptrid.
177 	 * See the code in dt_pragma.c for details on deferred ident pragmas.
178 	 */
179 	if (dtp->dt_globals->dh_defer != NULL && yypcb->pcb_pragmas != NULL &&
180 	    dt_idhash_lookup(yypcb->pcb_pragmas, "translator") != NULL) {
181 		dtp->dt_globals->dh_defer(dtp->dt_globals, &dxp->dx_souid);
182 		dxp->dx_ptrid.di_attr = dxp->dx_souid.di_attr;
183 		dxp->dx_ptrid.di_vers = dxp->dx_souid.di_vers;
184 	}
185 
186 	dxp->dx_src_ctfp = src->dtt_ctfp;
187 	dxp->dx_src_type = src->dtt_type;
188 	dxp->dx_src_base = ctf_type_resolve(src->dtt_ctfp, src->dtt_type);
189 
190 	dxp->dx_dst_ctfp = dst->dtt_ctfp;
191 	dxp->dx_dst_type = dst->dtt_type;
192 	dxp->dx_dst_base = ctf_type_resolve(dst->dtt_ctfp, dst->dtt_type);
193 
194 	kind = ctf_type_kind(dst->dtt_ctfp, dxp->dx_dst_base);
195 	assert(kind == CTF_K_STRUCT || kind == CTF_K_UNION);
196 
197 	/*
198 	 * If no input parameter is given, we're making a dynamic translator:
199 	 * create member nodes for every member of the output type.  Otherwise
200 	 * retain the member and allocation node lists presented by the parser.
201 	 */
202 	if (name == NULL) {
203 		if (ctf_member_iter(dxp->dx_dst_ctfp, dxp->dx_dst_base,
204 		    dt_xlator_create_member, dxp) != 0)
205 			goto err;
206 	} else {
207 		dxp->dx_members = members;
208 		dxp->dx_nodes = nodes;
209 	}
210 
211 	/*
212 	 * Assign member IDs to each member and allocate space for DIFOs
213 	 * if and when this translator is eventually compiled.
214 	 */
215 	for (dnp = dxp->dx_members; dnp != NULL; dnp = dnp->dn_list) {
216 		dnp->dn_membxlator = dxp;
217 		dnp->dn_membid = dxp->dx_nmembers++;
218 	}
219 
220 	dxp->dx_membdif = dt_zalloc(dtp,
221 	    sizeof (dtrace_difo_t *) * dxp->dx_nmembers);
222 
223 	if (dxp->dx_membdif == NULL) {
224 		dxp->dx_nmembers = 0;
225 		goto err;
226 	}
227 
228 	return (dxp);
229 
230 err:
231 	dt_xlator_destroy(dtp, dxp);
232 	return (NULL);
233 }
234 
235 void
236 dt_xlator_destroy(dtrace_hdl_t *dtp, dt_xlator_t *dxp)
237 {
238 	uint_t i;
239 
240 	dt_node_link_free(&dxp->dx_nodes);
241 
242 	if (dxp->dx_locals != NULL)
243 		dt_idhash_destroy(dxp->dx_locals);
244 	else if (dxp->dx_ident != NULL)
245 		dt_ident_destroy(dxp->dx_ident);
246 
247 	for (i = 0; i < dxp->dx_nmembers; i++)
248 		dt_difo_free(dtp, dxp->dx_membdif[i]);
249 
250 	dt_free(dtp, dxp->dx_membdif);
251 	dt_list_delete(&dtp->dt_xlators, dxp);
252 	dt_free(dtp, dxp);
253 }
254 
255 dt_xlator_t *
256 dt_xlator_lookup(dtrace_hdl_t *dtp, dt_node_t *src, dt_node_t *dst, int flags)
257 {
258 	ctf_file_t *src_ctfp = src->dn_ctfp;
259 	ctf_id_t src_type = src->dn_type;
260 	ctf_id_t src_base = ctf_type_resolve(src_ctfp, src_type);
261 
262 	ctf_file_t *dst_ctfp = dst->dn_ctfp;
263 	ctf_id_t dst_type = dst->dn_type;
264 	ctf_id_t dst_base = ctf_type_resolve(dst_ctfp, dst_type);
265 	uint_t dst_kind = ctf_type_kind(dst_ctfp, dst_base);
266 
267 	int ptr = dst_kind == CTF_K_POINTER;
268 	dtrace_typeinfo_t src_dtt, dst_dtt;
269 	dt_node_t xn = { 0 };
270 	dt_xlator_t *dxp = NULL;
271 
272 	if (src_base == CTF_ERR || dst_base == CTF_ERR)
273 		return (NULL); /* fail if these are unresolvable types */
274 
275 	/*
276 	 * Translators are always defined using a struct or union type, so if
277 	 * we are attempting to translate to type "T *", we internally look
278 	 * for a translation to type "T" by following the pointer reference.
279 	 */
280 	if (ptr) {
281 		dst_type = ctf_type_reference(dst_ctfp, dst_type);
282 		dst_base = ctf_type_resolve(dst_ctfp, dst_type);
283 		dst_kind = ctf_type_kind(dst_ctfp, dst_base);
284 	}
285 
286 	if (dst_kind != CTF_K_UNION && dst_kind != CTF_K_STRUCT)
287 		return (NULL); /* fail if the output isn't a struct or union */
288 
289 	/*
290 	 * In order to find a matching translator, we iterate over the set of
291 	 * available translators in three passes.  First, we look for a
292 	 * translation from the exact source type to the resolved destination.
293 	 * Second, we look for a translation from the resolved source type to
294 	 * the resolved destination.  Third, we look for a translation from a
295 	 * compatible source type (using the same rules as parameter formals)
296 	 * to the resolved destination.  If all passes fail, return NULL.
297 	 */
298 	for (dxp = dt_list_next(&dtp->dt_xlators); dxp != NULL;
299 	    dxp = dt_list_next(dxp)) {
300 		if (ctf_type_compat(dxp->dx_src_ctfp, dxp->dx_src_type,
301 		    src_ctfp, src_type) &&
302 		    ctf_type_compat(dxp->dx_dst_ctfp, dxp->dx_dst_base,
303 		    dst_ctfp, dst_base))
304 			goto out;
305 	}
306 
307 	if (flags & DT_XLATE_EXACT)
308 		goto out; /* skip remaining passes if exact match required */
309 
310 	for (dxp = dt_list_next(&dtp->dt_xlators); dxp != NULL;
311 	    dxp = dt_list_next(dxp)) {
312 		if (ctf_type_compat(dxp->dx_src_ctfp, dxp->dx_src_base,
313 		    src_ctfp, src_type) &&
314 		    ctf_type_compat(dxp->dx_dst_ctfp, dxp->dx_dst_base,
315 		    dst_ctfp, dst_base))
316 			goto out;
317 	}
318 
319 	for (dxp = dt_list_next(&dtp->dt_xlators); dxp != NULL;
320 	    dxp = dt_list_next(dxp)) {
321 		dt_node_type_assign(&xn, dxp->dx_src_ctfp, dxp->dx_src_type);
322 		if (ctf_type_compat(dxp->dx_dst_ctfp, dxp->dx_dst_base,
323 		    dst_ctfp, dst_base) && dt_node_is_argcompat(src, &xn))
324 			goto out;
325 	}
326 
327 out:
328 	if (ptr && dxp != NULL && dxp->dx_ptrid.di_type == CTF_ERR)
329 		return (NULL);	/* no translation available to pointer type */
330 
331 	if (dxp != NULL || !(flags & DT_XLATE_EXTERN) ||
332 	    dtp->dt_xlatemode == DT_XL_STATIC)
333 		return (dxp);	/* we succeeded or not allowed to extern */
334 
335 	/*
336 	 * If we get here, then we didn't find an existing translator, but the
337 	 * caller and xlatemode permit us to create an extern to a dynamic one.
338 	 */
339 	src_dtt.dtt_object = dt_module_lookup_by_ctf(dtp, src_ctfp)->dm_name;
340 	src_dtt.dtt_ctfp = src_ctfp;
341 	src_dtt.dtt_type = src_type;
342 
343 	dst_dtt.dtt_object = dt_module_lookup_by_ctf(dtp, dst_ctfp)->dm_name;
344 	dst_dtt.dtt_ctfp = dst_ctfp;
345 	dst_dtt.dtt_type = dst_type;
346 
347 	return (dt_xlator_create(dtp, &src_dtt, &dst_dtt, NULL, NULL, NULL));
348 }
349 
350 dt_xlator_t *
351 dt_xlator_lookup_id(dtrace_hdl_t *dtp, id_t id)
352 {
353 	assert(id >= 0 && id < dtp->dt_xlatorid);
354 	return (dtp->dt_xlatormap[id]);
355 }
356 
357 dt_ident_t *
358 dt_xlator_ident(dt_xlator_t *dxp, ctf_file_t *ctfp, ctf_id_t type)
359 {
360 	if (ctf_type_kind(ctfp, ctf_type_resolve(ctfp, type)) == CTF_K_POINTER)
361 		return (&dxp->dx_ptrid);
362 	else
363 		return (&dxp->dx_souid);
364 }
365 
366 dt_node_t *
367 dt_xlator_member(dt_xlator_t *dxp, const char *name)
368 {
369 	dt_node_t *dnp;
370 
371 	for (dnp = dxp->dx_members; dnp != NULL; dnp = dnp->dn_list) {
372 		if (strcmp(dnp->dn_membname, name) == 0)
373 			return (dnp);
374 	}
375 
376 	return (NULL);
377 }
378 
379 int
380 dt_xlator_dynamic(const dt_xlator_t *dxp)
381 {
382 	return (dxp->dx_locals == NULL);
383 }
384