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  * Copyright (c) 2013 by Delphix. All rights reserved.
  28  * Copyright (c) 2013 Joyent, Inc. All rights reserved.
  29  */
  30 
  31 #include <strings.h>
  32 #include <assert.h>
  33 
  34 #include <dt_xlator.h>
  35 #include <dt_parser.h>
  36 #include <dt_grammar.h>
  37 #include <dt_module.h>
  38 #include <dt_impl.h>
  39 
  40 /*
  41  * Create a member node corresponding to one of the output members of a dynamic
  42  * translator.  We set the member's dn_membexpr to a DT_NODE_XLATOR node that
  43  * has dn_op set to DT_TOK_XLATE and refers back to the translator itself.  The
  44  * code generator will then use this as the indicator for dynamic translation.
  45  */
  46 /*ARGSUSED*/
  47 static int
  48 dt_xlator_create_member(const char *name, ctf_id_t type, ulong_t off, void *arg)
  49 {
  50         dt_xlator_t *dxp = arg;
  51         dtrace_hdl_t *dtp = dxp->dx_hdl;
  52         dt_node_t *enp, *mnp;
  53 
  54         if ((enp = dt_node_xalloc(dtp, DT_NODE_XLATOR)) == NULL)
  55                 return (dt_set_errno(dtp, EDT_NOMEM));
  56 
  57         enp->dn_link = dxp->dx_nodes;
  58         dxp->dx_nodes = enp;
  59 
  60         if ((mnp = dt_node_xalloc(dtp, DT_NODE_MEMBER)) == NULL)
  61                 return (dt_set_errno(dtp, EDT_NOMEM));
  62 
  63         mnp->dn_link = dxp->dx_nodes;
  64         dxp->dx_nodes = mnp;
  65 
  66         /*
  67          * For the member expression, we use a DT_NODE_XLATOR/TOK_XLATE whose
  68          * xlator refers back to the translator and whose dn_xmember refers to
  69          * the current member.  These refs will be used by dt_cg.c and dt_as.c.
  70          */
  71         enp->dn_op = DT_TOK_XLATE;
  72         enp->dn_xlator = dxp;
  73         enp->dn_xmember = mnp;
  74         dt_node_type_assign(enp, dxp->dx_dst_ctfp, type, B_FALSE);
  75 
  76         /*
  77          * For the member itself, we use a DT_NODE_MEMBER as usual with the
  78          * appropriate name, output type, and member expression set to 'enp'.
  79          */
  80         if (dxp->dx_members != NULL) {
  81                 assert(enp->dn_link->dn_kind == DT_NODE_MEMBER);
  82                 enp->dn_link->dn_list = mnp;
  83         } else
  84                 dxp->dx_members = mnp;
  85 
  86         mnp->dn_membname = strdup(name);
  87         mnp->dn_membexpr = enp;
  88         dt_node_type_assign(mnp, dxp->dx_dst_ctfp, type, B_FALSE);
  89 
  90         if (mnp->dn_membname == NULL)
  91                 return (dt_set_errno(dtp, EDT_NOMEM));
  92 
  93         return (0);
  94 }
  95 
  96 dt_xlator_t *
  97 dt_xlator_create(dtrace_hdl_t *dtp,
  98     const dtrace_typeinfo_t *src, const dtrace_typeinfo_t *dst,
  99     const char *name, dt_node_t *members, dt_node_t *nodes)
 100 {
 101         dt_xlator_t *dxp = dt_zalloc(dtp, sizeof (dt_xlator_t));
 102         dtrace_typeinfo_t ptr = *dst;
 103         dt_xlator_t **map;
 104         dt_node_t *dnp;
 105         uint_t kind;
 106 
 107         if (dxp == NULL)
 108                 return (NULL);
 109 
 110         dxp->dx_hdl = dtp;
 111         dxp->dx_id = dtp->dt_xlatorid++;
 112         dxp->dx_gen = dtp->dt_gen;
 113         dxp->dx_arg = -1;
 114 
 115         if ((map = dt_alloc(dtp, sizeof (void *) * (dxp->dx_id + 1))) == NULL) {
 116                 dt_free(dtp, dxp);
 117                 return (NULL);
 118         }
 119 
 120         dt_list_append(&dtp->dt_xlators, dxp);
 121         bcopy(dtp->dt_xlatormap, map, sizeof (void *) * dxp->dx_id);
 122         dt_free(dtp, dtp->dt_xlatormap);
 123         dtp->dt_xlatormap = map;
 124         dtp->dt_xlatormap[dxp->dx_id] = dxp;
 125 
 126         if (dt_type_pointer(&ptr) == -1) {
 127                 ptr.dtt_ctfp = NULL;
 128                 ptr.dtt_type = CTF_ERR;
 129         }
 130 
 131         dxp->dx_ident = dt_ident_create(name ? name : "T",
 132             DT_IDENT_SCALAR, DT_IDFLG_REF | DT_IDFLG_ORPHAN, 0,
 133             _dtrace_defattr, 0, &dt_idops_thaw, NULL, dtp->dt_gen);
 134 
 135         if (dxp->dx_ident == NULL)
 136                 goto err; /* no memory for identifier */
 137 
 138         dxp->dx_ident->di_ctfp = src->dtt_ctfp;
 139         dxp->dx_ident->di_type = src->dtt_type;
 140 
 141         /*
 142          * If an input parameter name is given, this is a static translator
 143          * definition: create an idhash and identifier for the parameter.
 144          */
 145         if (name != NULL) {
 146                 dxp->dx_locals = dt_idhash_create("xlparams", NULL, 0, 0);
 147 
 148                 if (dxp->dx_locals == NULL)
 149                         goto err; /* no memory for identifier hash */
 150 
 151                 dt_idhash_xinsert(dxp->dx_locals, dxp->dx_ident);
 152         }
 153 
 154         dxp->dx_souid.di_name = "translator";
 155         dxp->dx_souid.di_kind = DT_IDENT_XLSOU;
 156         dxp->dx_souid.di_flags = DT_IDFLG_REF;
 157         dxp->dx_souid.di_id = dxp->dx_id;
 158         dxp->dx_souid.di_attr = _dtrace_defattr;
 159         dxp->dx_souid.di_ops = &dt_idops_thaw;
 160         dxp->dx_souid.di_data = dxp;
 161         dxp->dx_souid.di_ctfp = dst->dtt_ctfp;
 162         dxp->dx_souid.di_type = dst->dtt_type;
 163         dxp->dx_souid.di_gen = dtp->dt_gen;
 164 
 165         dxp->dx_ptrid.di_name = "translator";
 166         dxp->dx_ptrid.di_kind = DT_IDENT_XLPTR;
 167         dxp->dx_ptrid.di_flags = DT_IDFLG_REF;
 168         dxp->dx_ptrid.di_id = dxp->dx_id;
 169         dxp->dx_ptrid.di_attr = _dtrace_defattr;
 170         dxp->dx_ptrid.di_ops = &dt_idops_thaw;
 171         dxp->dx_ptrid.di_data = dxp;
 172         dxp->dx_ptrid.di_ctfp = ptr.dtt_ctfp;
 173         dxp->dx_ptrid.di_type = ptr.dtt_type;
 174         dxp->dx_ptrid.di_gen = dtp->dt_gen;
 175 
 176         /*
 177          * If a deferred pragma is pending on the keyword "translator", run all
 178          * the deferred pragmas on dx_souid and then copy results to dx_ptrid.
 179          * See the code in dt_pragma.c for details on deferred ident pragmas.
 180          */
 181         if (dtp->dt_globals->dh_defer != NULL && yypcb->pcb_pragmas != NULL &&
 182             dt_idhash_lookup(yypcb->pcb_pragmas, "translator") != NULL) {
 183                 dtp->dt_globals->dh_defer(dtp->dt_globals, &dxp->dx_souid);
 184                 dxp->dx_ptrid.di_attr = dxp->dx_souid.di_attr;
 185                 dxp->dx_ptrid.di_vers = dxp->dx_souid.di_vers;
 186         }
 187 
 188         dxp->dx_src_ctfp = src->dtt_ctfp;
 189         dxp->dx_src_type = src->dtt_type;
 190         dxp->dx_src_base = ctf_type_resolve(src->dtt_ctfp, src->dtt_type);
 191 
 192         dxp->dx_dst_ctfp = dst->dtt_ctfp;
 193         dxp->dx_dst_type = dst->dtt_type;
 194         dxp->dx_dst_base = ctf_type_resolve(dst->dtt_ctfp, dst->dtt_type);
 195 
 196         kind = ctf_type_kind(dst->dtt_ctfp, dxp->dx_dst_base);
 197         assert(kind == CTF_K_STRUCT || kind == CTF_K_UNION);
 198 
 199         /*
 200          * If no input parameter is given, we're making a dynamic translator:
 201          * create member nodes for every member of the output type.  Otherwise
 202          * retain the member and allocation node lists presented by the parser.
 203          */
 204         if (name == NULL) {
 205                 if (ctf_member_iter(dxp->dx_dst_ctfp, dxp->dx_dst_base,
 206                     dt_xlator_create_member, dxp) != 0)
 207                         goto err;
 208         } else {
 209                 dxp->dx_members = members;
 210                 dxp->dx_nodes = nodes;
 211         }
 212 
 213         /*
 214          * Assign member IDs to each member and allocate space for DIFOs
 215          * if and when this translator is eventually compiled.
 216          */
 217         for (dnp = dxp->dx_members; dnp != NULL; dnp = dnp->dn_list) {
 218                 dnp->dn_membxlator = dxp;
 219                 dnp->dn_membid = dxp->dx_nmembers++;
 220         }
 221 
 222         dxp->dx_membdif = dt_zalloc(dtp,
 223             sizeof (dtrace_difo_t *) * dxp->dx_nmembers);
 224 
 225         if (dxp->dx_membdif == NULL) {
 226                 dxp->dx_nmembers = 0;
 227                 goto err;
 228         }
 229 
 230         return (dxp);
 231 
 232 err:
 233         dt_xlator_destroy(dtp, dxp);
 234         return (NULL);
 235 }
 236 
 237 void
 238 dt_xlator_destroy(dtrace_hdl_t *dtp, dt_xlator_t *dxp)
 239 {
 240         uint_t i;
 241 
 242         dt_node_link_free(&dxp->dx_nodes);
 243 
 244         if (dxp->dx_locals != NULL)
 245                 dt_idhash_destroy(dxp->dx_locals);
 246         else if (dxp->dx_ident != NULL)
 247                 dt_ident_destroy(dxp->dx_ident);
 248 
 249         for (i = 0; i < dxp->dx_nmembers; i++)
 250                 dt_difo_free(dtp, dxp->dx_membdif[i]);
 251 
 252         dt_free(dtp, dxp->dx_membdif);
 253         dt_list_delete(&dtp->dt_xlators, dxp);
 254         dt_free(dtp, dxp);
 255 }
 256 
 257 dt_xlator_t *
 258 dt_xlator_lookup(dtrace_hdl_t *dtp, dt_node_t *src, dt_node_t *dst, int flags)
 259 {
 260         ctf_file_t *src_ctfp = src->dn_ctfp;
 261         ctf_id_t src_type = src->dn_type;
 262         ctf_id_t src_base = ctf_type_resolve(src_ctfp, src_type);
 263 
 264         ctf_file_t *dst_ctfp = dst->dn_ctfp;
 265         ctf_id_t dst_type = dst->dn_type;
 266         ctf_id_t dst_base = ctf_type_resolve(dst_ctfp, dst_type);
 267         uint_t dst_kind = ctf_type_kind(dst_ctfp, dst_base);
 268 
 269         int ptr = dst_kind == CTF_K_POINTER;
 270         dtrace_typeinfo_t src_dtt, dst_dtt;
 271         dt_node_t xn = { 0 };
 272         dt_xlator_t *dxp = NULL;
 273 
 274         if (src_base == CTF_ERR || dst_base == CTF_ERR)
 275                 return (NULL); /* fail if these are unresolvable types */
 276 
 277         /*
 278          * Translators are always defined using a struct or union type, so if
 279          * we are attempting to translate to type "T *", we internally look
 280          * for a translation to type "T" by following the pointer reference.
 281          */
 282         if (ptr) {
 283                 dst_type = ctf_type_reference(dst_ctfp, dst_type);
 284                 dst_base = ctf_type_resolve(dst_ctfp, dst_type);
 285                 dst_kind = ctf_type_kind(dst_ctfp, dst_base);
 286         }
 287 
 288         if (dst_kind != CTF_K_UNION && dst_kind != CTF_K_STRUCT)
 289                 return (NULL); /* fail if the output isn't a struct or union */
 290 
 291         /*
 292          * In order to find a matching translator, we iterate over the set of
 293          * available translators in three passes.  First, we look for a
 294          * translation from the exact source type to the resolved destination.
 295          * Second, we look for a translation from the resolved source type to
 296          * the resolved destination.  Third, we look for a translation from a
 297          * compatible source type (using the same rules as parameter formals)
 298          * to the resolved destination.  If all passes fail, return NULL.
 299          */
 300         for (dxp = dt_list_next(&dtp->dt_xlators); dxp != NULL;
 301             dxp = dt_list_next(dxp)) {
 302                 if (ctf_type_compat(dxp->dx_src_ctfp, dxp->dx_src_type,
 303                     src_ctfp, src_type) &&
 304                     ctf_type_compat(dxp->dx_dst_ctfp, dxp->dx_dst_base,
 305                     dst_ctfp, dst_base))
 306                         goto out;
 307         }
 308 
 309         if (flags & DT_XLATE_EXACT)
 310                 goto out; /* skip remaining passes if exact match required */
 311 
 312         for (dxp = dt_list_next(&dtp->dt_xlators); dxp != NULL;
 313             dxp = dt_list_next(dxp)) {
 314                 if (ctf_type_compat(dxp->dx_src_ctfp, dxp->dx_src_base,
 315                     src_ctfp, src_type) &&
 316                     ctf_type_compat(dxp->dx_dst_ctfp, dxp->dx_dst_base,
 317                     dst_ctfp, dst_base))
 318                         goto out;
 319         }
 320 
 321         for (dxp = dt_list_next(&dtp->dt_xlators); dxp != NULL;
 322             dxp = dt_list_next(dxp)) {
 323                 dt_node_type_assign(&xn, dxp->dx_src_ctfp, dxp->dx_src_type,
 324                     B_FALSE);
 325                 if (ctf_type_compat(dxp->dx_dst_ctfp, dxp->dx_dst_base,
 326                     dst_ctfp, dst_base) && dt_node_is_argcompat(src, &xn))
 327                         goto out;
 328         }
 329 
 330 out:
 331         if (ptr && dxp != NULL && dxp->dx_ptrid.di_type == CTF_ERR)
 332                 return (NULL);  /* no translation available to pointer type */
 333 
 334         if (dxp != NULL || !(flags & DT_XLATE_EXTERN) ||
 335             dtp->dt_xlatemode == DT_XL_STATIC)
 336                 return (dxp);   /* we succeeded or not allowed to extern */
 337 
 338         /*
 339          * If we get here, then we didn't find an existing translator, but the
 340          * caller and xlatemode permit us to create an extern to a dynamic one.
 341          */
 342         src_dtt.dtt_object = dt_module_lookup_by_ctf(dtp, src_ctfp)->dm_name;
 343         src_dtt.dtt_ctfp = src_ctfp;
 344         src_dtt.dtt_type = src_type;
 345 
 346         dst_dtt.dtt_object = dt_module_lookup_by_ctf(dtp, dst_ctfp)->dm_name;
 347         dst_dtt.dtt_ctfp = dst_ctfp;
 348         dst_dtt.dtt_type = dst_type;
 349 
 350         return (dt_xlator_create(dtp, &src_dtt, &dst_dtt, NULL, NULL, NULL));
 351 }
 352 
 353 dt_xlator_t *
 354 dt_xlator_lookup_id(dtrace_hdl_t *dtp, id_t id)
 355 {
 356         assert(id >= 0 && id < dtp->dt_xlatorid);
 357         return (dtp->dt_xlatormap[id]);
 358 }
 359 
 360 dt_ident_t *
 361 dt_xlator_ident(dt_xlator_t *dxp, ctf_file_t *ctfp, ctf_id_t type)
 362 {
 363         if (ctf_type_kind(ctfp, ctf_type_resolve(ctfp, type)) == CTF_K_POINTER)
 364                 return (&dxp->dx_ptrid);
 365         else
 366                 return (&dxp->dx_souid);
 367 }
 368 
 369 dt_node_t *
 370 dt_xlator_member(dt_xlator_t *dxp, const char *name)
 371 {
 372         dt_node_t *dnp;
 373 
 374         for (dnp = dxp->dx_members; dnp != NULL; dnp = dnp->dn_list) {
 375                 if (strcmp(dnp->dn_membname, name) == 0)
 376                         return (dnp);
 377         }
 378 
 379         return (NULL);
 380 }
 381 
 382 int
 383 dt_xlator_dynamic(const dt_xlator_t *dxp)
 384 {
 385         return (dxp->dx_locals == NULL);
 386 }