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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 /*
  26  * Copyright 2012 Jason King.  All rights reserved.
  27  * Use is subject to license terms.
  28  */
  29 
  30 /*
  31  * Copyright 2019 Joyent, Inc.
  32  */
  33 
  34 /*
  35  * CTF DWARF conversion theory.
  36  *
  37  * DWARF data contains a series of compilation units. Each compilation unit
  38  * generally refers to an object file or what once was, in the case of linked
  39  * binaries and shared objects. Each compilation unit has a series of what DWARF
  40  * calls a DIE (Debugging Information Entry). The set of entries that we care
  41  * about have type information stored in a series of attributes. Each DIE also
  42  * has a tag that identifies the kind of attributes that it has.
  43  *
  44  * A given DIE may itself have children. For example, a DIE that represents a
  45  * structure has children which represent members. Whenever we encounter a DIE
  46  * that has children or other values or types associated with it, we recursively
  47  * process those children first so that way we can then refer to the generated
  48  * CTF type id while processing its parent. This reduces the amount of unknowns
  49  * and fixups that we need. It also ensures that we don't accidentally add types
  50  * that an overzealous compiler might add to the DWARF data but aren't used by
  51  * anything in the system.
  52  *
  53  * Once we do a conversion, we store a mapping in an AVL tree that goes from the
  54  * DWARF's die offset, which is relative to the given compilation unit, to a
  55  * ctf_id_t.
  56  *
  57  * Unfortunately, some compilers actually will emit duplicate entries for a
  58  * given type that look similar, but aren't quite. To that end, we go through
  59  * and do a variant on a merge once we're done processing a single compilation
  60  * unit which deduplicates all of the types that are in the unit.
  61  *
  62  * Finally, if we encounter an object that has multiple compilation units, then
  63  * we'll convert all of the compilation units separately and then do a merge, so
  64  * that way we can result in one single ctf_file_t that represents everything
  65  * for the object.
  66  *
  67  * Conversion Steps
  68  * ----------------
  69  *
  70  * Because a given object we've been given to convert may have multiple
  71  * compilation units, we break the work into two halves. The first half
  72  * processes each compilation unit (potentially in parallel) and then the second
  73  * half optionally merges all of the dies in the first half. First, we'll cover
  74  * what's involved in converting a single ctf_cu_t's dwarf to CTF. This covers
  75  * the work done in ctf_dwarf_convert_one().
  76  *
  77  * An individual ctf_cu_t, which represents a compilation unit, is converted to
  78  * CTF in a series of multiple passes.
  79  *
  80  * Pass 1: During the first pass we walk all of the top-level dies and if we
  81  * find a function, variable, struct, union, enum or typedef, we recursively
  82  * transform all of its types. We don't recurse or process everything, because
  83  * we don't want to add some of the types that compilers may add which are
  84  * effectively unused.
  85  *
  86  * During pass 1, if we encounter any structures or unions we mark them for
  87  * fixing up later. This is necessary because we may not be able to determine
  88  * the full size of a structure at the beginning of time. This will happen if
  89  * the DWARF attribute DW_AT_byte_size is not present for a member. Because of
  90  * this possibility we defer adding members to structures or even converting
  91  * them during pass 1 and save that for pass 2. Adding all of the base
  92  * structures without any of their members helps deal with any circular
  93  * dependencies that we might encounter.
  94  *
  95  * Pass 2: This pass is used to do the first half of fixing up structures and
  96  * unions. Rather than walk the entire type space again, we actually walk the
  97  * list of structures and unions that we marked for later fixing up. Here, we
  98  * iterate over every structure and add members to the underlying ctf_file_t,
  99  * but not to the structs themselves. One might wonder why we don't, and the
 100  * main reason is that libctf requires a ctf_update() be done before adding the
 101  * members to structures or unions.
 102  *
 103  * Pass 3: This pass is used to do the second half of fixing up structures and
 104  * unions. During this part we always go through and add members to structures
 105  * and unions that we added to the container in the previous pass. In addition,
 106  * we set the structure and union's actual size, which may have additional
 107  * padding added by the compiler, it isn't simply the last offset. DWARF always
 108  * guarantees an attribute exists for this. Importantly no ctf_id_t's change
 109  * during pass 2.
 110  *
 111  * Pass 4: The next phase is to add CTF entries for all of the symbols and
 112  * variables that are present in this die. During pass 1 we added entries to a
 113  * map for each variable and function. During this pass, we iterate over the
 114  * symbol table and when we encounter a symbol that we have in our lists of
 115  * translated information which matches, we then add it to the ctf_file_t.
 116  *
 117  * Pass 5: Here we go and look for any weak symbols and functions and see if
 118  * they match anything that we recognize. If so, then we add type information
 119  * for them at this point based on the matching type.
 120  *
 121  * Pass 6: This pass is actually a variant on a merge. The traditional merge
 122  * process expects there to be no duplicate types. As such, at the end of
 123  * conversion, we do a dedup on all of the types in the system. The
 124  * deduplication process is described in lib/libctf/common/ctf_merge.c.
 125  *
 126  * Once pass 6 is done, we've finished processing the individual compilation
 127  * unit.
 128  *
 129  * The following steps reflect the general process of doing a conversion.
 130  *
 131  * 1) Walk the dwarf section and determine the number of compilation units
 132  * 2) Create a ctf_cu_t for each compilation unit
 133  * 3) Add all ctf_cu_t's to a workq
 134  * 4) Have the workq process each die with ctf_dwarf_convert_one. This itself
 135  *    is comprised of several steps, which were already enumerated.
 136  * 5) If we have multiple cu's, we do a ctf merge of all the dies. The mechanics
 137  *    of the merge are discussed in lib/libctf/common/ctf_merge.c.
 138  * 6) Free everything up and return a ctf_file_t to the user. If we only had a
 139  *    single compilation unit, then we give that to the user. Otherwise, we
 140  *    return the merged ctf_file_t.
 141  *
 142  * Threading
 143  * ---------
 144  *
 145  * The process has been designed to be amenable to threading. Each compilation
 146  * unit has its own type stream, therefore the logical place to divide and
 147  * conquer is at the compilation unit. Each ctf_cu_t has been built to be able
 148  * to be processed independently of the others. It has its own libdwarf handle,
 149  * as a given libdwarf handle may only be used by a single thread at a time.
 150  * This allows the various ctf_cu_t's to be processed in parallel by different
 151  * threads.
 152  *
 153  * All of the ctf_cu_t's are loaded into a workq which allows for a number of
 154  * threads to be specified and used as a thread pool to process all of the
 155  * queued work. We set the number of threads to use in the workq equal to the
 156  * number of threads that the user has specified.
 157  *
 158  * After all of the compilation units have been drained, we use the same number
 159  * of threads when performing a merge of multiple compilation units, if they
 160  * exist.
 161  *
 162  * While all of these different parts do support and allow for multiple threads,
 163  * it's important that when only a single thread is specified, that it be the
 164  * calling thread. This allows the conversion routines to be used in a context
 165  * that doesn't allow additional threads, such as rtld.
 166  *
 167  * Common DWARF Mechanics and Notes
 168  * --------------------------------
 169  *
 170  * At this time, we really only support DWARFv2, though support for DWARFv4 is
 171  * mostly there. There is no intent to support DWARFv3.
 172  *
 173  * Generally types for something are stored in the DW_AT_type attribute. For
 174  * example, a function's return type will be stored in the local DW_AT_type
 175  * attribute while the arguments will be in child DIEs. There are also various
 176  * times when we don't have any DW_AT_type. In that case, the lack of a type
 177  * implies, at least for C, that its C type is void. Because DWARF doesn't emit
 178  * one, we have a synthetic void type that we create and manipulate instead and
 179  * pass it off to consumers on an as-needed basis. If nothing has a void type,
 180  * it will not be emitted.
 181  *
 182  * Architecture Specific Parts
 183  * ---------------------------
 184  *
 185  * The CTF tooling encodes various information about the various architectures
 186  * in the system. Importantly, the tool assumes that every architecture has a
 187  * data model where long and pointer are the same size. This is currently the
 188  * case, as the two data models illumos supports are ILP32 and LP64.
 189  *
 190  * In addition, we encode the mapping of various floating point sizes to various
 191  * types for each architecture. If a new architecture is being added, it should
 192  * be added to the list. The general design of the ctf conversion tools is to be
 193  * architecture independent. eg. any of the tools here should be able to convert
 194  * any architecture's DWARF into ctf; however, this has not been rigorously
 195  * tested and more importantly, the ctf routines don't currently write out the
 196  * data in an endian-aware form, they only use that of the currently running
 197  * library.
 198  */
 199 
 200 #include <libctf_impl.h>
 201 #include <sys/avl.h>
 202 #include <sys/debug.h>
 203 #include <gelf.h>
 204 #include <libdwarf.h>
 205 #include <dwarf.h>
 206 #include <libgen.h>
 207 #include <workq.h>
 208 #include <errno.h>
 209 
 210 #define DWARF_VERSION_TWO       2
 211 #define DWARF_VARARGS_NAME      "..."
 212 
 213 /*
 214  * Dwarf may refer recursively to other types that we've already processed. To
 215  * see if we've already converted them, we look them up in an AVL tree that's
 216  * sorted by the DWARF id.
 217  */
 218 typedef struct ctf_dwmap {
 219         avl_node_t      cdm_avl;
 220         Dwarf_Off       cdm_off;
 221         Dwarf_Die       cdm_die;
 222         ctf_id_t        cdm_id;
 223         boolean_t       cdm_fix;
 224 } ctf_dwmap_t;
 225 
 226 typedef struct ctf_dwvar {
 227         ctf_list_t      cdv_list;
 228         char            *cdv_name;
 229         ctf_id_t        cdv_type;
 230         boolean_t       cdv_global;
 231 } ctf_dwvar_t;
 232 
 233 typedef struct ctf_dwfunc {
 234         ctf_list_t      cdf_list;
 235         char            *cdf_name;
 236         ctf_funcinfo_t  cdf_fip;
 237         ctf_id_t        *cdf_argv;
 238         boolean_t       cdf_global;
 239 } ctf_dwfunc_t;
 240 
 241 typedef struct ctf_dwbitf {
 242         ctf_list_t      cdb_list;
 243         ctf_id_t        cdb_base;
 244         uint_t          cdb_nbits;
 245         ctf_id_t        cdb_id;
 246 } ctf_dwbitf_t;
 247 
 248 /*
 249  * The ctf_cu_t represents a single top-level DWARF die unit. While generally,
 250  * the typical object file has only a single die, if we're asked to convert
 251  * something that's been linked from multiple sources, multiple dies will exist.
 252  */
 253 typedef struct ctf_die {
 254         Elf             *cu_elf;        /* shared libelf handle */
 255         char            *cu_name;       /* basename of the DIE */
 256         ctf_merge_t     *cu_cmh;        /* merge handle */
 257         ctf_list_t      cu_vars;        /* List of variables */
 258         ctf_list_t      cu_funcs;       /* List of functions */
 259         ctf_list_t      cu_bitfields;   /* Bit field members */
 260         Dwarf_Debug     cu_dwarf;       /* libdwarf handle */
 261         Dwarf_Die       cu_cu;          /* libdwarf compilation unit */
 262         Dwarf_Off       cu_cuoff;       /* cu's offset */
 263         Dwarf_Off       cu_maxoff;      /* maximum offset */
 264         ctf_file_t      *cu_ctfp;       /* output CTF file */
 265         avl_tree_t      cu_map;         /* map die offsets to CTF types */
 266         char            *cu_errbuf;     /* error message buffer */
 267         size_t          cu_errlen;      /* error message buffer length */
 268         size_t          cu_ptrsz;       /* object's pointer size */
 269         boolean_t       cu_bigend;      /* is it big endian */
 270         boolean_t       cu_doweaks;     /* should we convert weak symbols? */
 271         uint_t          cu_mach;        /* machine type */
 272         ctf_id_t        cu_voidtid;     /* void pointer */
 273         ctf_id_t        cu_longtid;     /* id for a 'long' */
 274 } ctf_cu_t;
 275 
 276 static int ctf_dwarf_offset(ctf_cu_t *, Dwarf_Die, Dwarf_Off *);
 277 static int ctf_dwarf_convert_die(ctf_cu_t *, Dwarf_Die);
 278 static int ctf_dwarf_convert_type(ctf_cu_t *, Dwarf_Die, ctf_id_t *, int);
 279 
 280 static int ctf_dwarf_function_count(ctf_cu_t *, Dwarf_Die, ctf_funcinfo_t *,
 281     boolean_t);
 282 static int ctf_dwarf_convert_fargs(ctf_cu_t *, Dwarf_Die, ctf_funcinfo_t *,
 283     ctf_id_t *);
 284 
 285 /*
 286  * This is a generic way to set a CTF Conversion backend error depending on what
 287  * we were doing. Unless it was one of a specific set of errors that don't
 288  * indicate a programming / translation bug, eg. ENOMEM, then we transform it
 289  * into a CTF backend error and fill in the error buffer.
 290  */
 291 static int
 292 ctf_dwarf_error(ctf_cu_t *cup, ctf_file_t *cfp, int err, const char *fmt, ...)
 293 {
 294         va_list ap;
 295         int ret;
 296         size_t off = 0;
 297         ssize_t rem = cup->cu_errlen;
 298         if (cfp != NULL)
 299                 err = ctf_errno(cfp);
 300 
 301         if (err == ENOMEM)
 302                 return (err);
 303 
 304         ret = snprintf(cup->cu_errbuf, rem, "die %s: ", cup->cu_name);
 305         if (ret < 0)
 306                 goto err;
 307         off += ret;
 308         rem = MAX(rem - ret, 0);
 309 
 310         va_start(ap, fmt);
 311         ret = vsnprintf(cup->cu_errbuf + off, rem, fmt, ap);
 312         va_end(ap);
 313         if (ret < 0)
 314                 goto err;
 315 
 316         off += ret;
 317         rem = MAX(rem - ret, 0);
 318         if (fmt[strlen(fmt) - 1] != '\n') {
 319                 (void) snprintf(cup->cu_errbuf + off, rem,
 320                     ": %s\n", ctf_errmsg(err));
 321         }
 322         va_end(ap);
 323         return (ECTF_CONVBKERR);
 324 
 325 err:
 326         cup->cu_errbuf[0] = '\0';
 327         return (ECTF_CONVBKERR);
 328 }
 329 
 330 /*
 331  * DWARF often opts to put no explicit type to describe a void type. eg. if we
 332  * have a reference type whose DW_AT_type member doesn't exist, then we should
 333  * instead assume it points to void. Because this isn't represented, we
 334  * instead cause it to come into existence.
 335  */
 336 static ctf_id_t
 337 ctf_dwarf_void(ctf_cu_t *cup)
 338 {
 339         if (cup->cu_voidtid == CTF_ERR) {
 340                 ctf_encoding_t enc = { CTF_INT_SIGNED, 0, 0 };
 341                 cup->cu_voidtid = ctf_add_integer(cup->cu_ctfp, CTF_ADD_ROOT,
 342                     "void", &enc);
 343                 if (cup->cu_voidtid == CTF_ERR) {
 344                         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 345                             "failed to create void type: %s\n",
 346                             ctf_errmsg(ctf_errno(cup->cu_ctfp)));
 347                 }
 348         }
 349 
 350         return (cup->cu_voidtid);
 351 }
 352 
 353 /*
 354  * There are many different forms that an array index may take. However, we just
 355  * always force it to be of a type long no matter what. Therefore we use this to
 356  * have a single instance of long across everything.
 357  */
 358 static ctf_id_t
 359 ctf_dwarf_long(ctf_cu_t *cup)
 360 {
 361         if (cup->cu_longtid == CTF_ERR) {
 362                 ctf_encoding_t enc;
 363 
 364                 enc.cte_format = CTF_INT_SIGNED;
 365                 enc.cte_offset = 0;
 366                 /* All illumos systems are LP */
 367                 enc.cte_bits = cup->cu_ptrsz * 8;
 368                 cup->cu_longtid = ctf_add_integer(cup->cu_ctfp, CTF_ADD_NONROOT,
 369                     "long", &enc);
 370                 if (cup->cu_longtid == CTF_ERR) {
 371                         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 372                             "failed to create long type: %s\n",
 373                             ctf_errmsg(ctf_errno(cup->cu_ctfp)));
 374                 }
 375 
 376         }
 377 
 378         return (cup->cu_longtid);
 379 }
 380 
 381 static int
 382 ctf_dwmap_comp(const void *a, const void *b)
 383 {
 384         const ctf_dwmap_t *ca = a;
 385         const ctf_dwmap_t *cb = b;
 386 
 387         if (ca->cdm_off > cb->cdm_off)
 388                 return (1);
 389         if (ca->cdm_off < cb->cdm_off)
 390                 return (-1);
 391         return (0);
 392 }
 393 
 394 static int
 395 ctf_dwmap_add(ctf_cu_t *cup, ctf_id_t id, Dwarf_Die die, boolean_t fix)
 396 {
 397         int ret;
 398         avl_index_t index;
 399         ctf_dwmap_t *dwmap;
 400         Dwarf_Off off;
 401 
 402         VERIFY(id > 0 && id < CTF_MAX_TYPE);
 403 
 404         if ((ret = ctf_dwarf_offset(cup, die, &off)) != 0)
 405                 return (ret);
 406 
 407         if ((dwmap = ctf_alloc(sizeof (ctf_dwmap_t))) == NULL)
 408                 return (ENOMEM);
 409 
 410         dwmap->cdm_die = die;
 411         dwmap->cdm_off = off;
 412         dwmap->cdm_id = id;
 413         dwmap->cdm_fix = fix;
 414 
 415         ctf_dprintf("dwmap: %p %" DW_PR_DUx "->%d\n", dwmap, off, id);
 416         VERIFY(avl_find(&cup->cu_map, dwmap, &index) == NULL);
 417         avl_insert(&cup->cu_map, dwmap, index);
 418         return (0);
 419 }
 420 
 421 static int
 422 ctf_dwarf_attribute(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Half name,
 423     Dwarf_Attribute *attrp)
 424 {
 425         int ret;
 426         Dwarf_Error derr;
 427 
 428         if ((ret = dwarf_attr(die, name, attrp, &derr)) == DW_DLV_OK)
 429                 return (0);
 430         if (ret == DW_DLV_NO_ENTRY) {
 431                 *attrp = NULL;
 432                 return (ENOENT);
 433         }
 434         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 435             "failed to get attribute for type: %s\n",
 436             dwarf_errmsg(derr));
 437         return (ECTF_CONVBKERR);
 438 }
 439 
 440 static int
 441 ctf_dwarf_ref(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Half name, Dwarf_Off *refp)
 442 {
 443         int ret;
 444         Dwarf_Attribute attr;
 445         Dwarf_Error derr;
 446 
 447         if ((ret = ctf_dwarf_attribute(cup, die, name, &attr)) != 0)
 448                 return (ret);
 449 
 450         if (dwarf_formref(attr, refp, &derr) == DW_DLV_OK) {
 451                 dwarf_dealloc(cup->cu_dwarf, attr, DW_DLA_ATTR);
 452                 return (0);
 453         }
 454 
 455         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 456             "failed to get unsigned attribute for type: %s\n",
 457             dwarf_errmsg(derr));
 458         return (ECTF_CONVBKERR);
 459 }
 460 
 461 static int
 462 ctf_dwarf_refdie(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Half name,
 463     Dwarf_Die *diep)
 464 {
 465         int ret;
 466         Dwarf_Off off;
 467         Dwarf_Error derr;
 468 
 469         if ((ret = ctf_dwarf_ref(cup, die, name, &off)) != 0)
 470                 return (ret);
 471 
 472         off += cup->cu_cuoff;
 473         if ((ret = dwarf_offdie(cup->cu_dwarf, off, diep, &derr)) !=
 474             DW_DLV_OK) {
 475                 (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 476                     "failed to get die from offset %" DW_PR_DUu ": %s\n",
 477                     off, dwarf_errmsg(derr));
 478                 return (ECTF_CONVBKERR);
 479         }
 480 
 481         return (0);
 482 }
 483 
 484 static int
 485 ctf_dwarf_signed(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Half name,
 486     Dwarf_Signed *valp)
 487 {
 488         int ret;
 489         Dwarf_Attribute attr;
 490         Dwarf_Error derr;
 491 
 492         if ((ret = ctf_dwarf_attribute(cup, die, name, &attr)) != 0)
 493                 return (ret);
 494 
 495         if (dwarf_formsdata(attr, valp, &derr) == DW_DLV_OK) {
 496                 dwarf_dealloc(cup->cu_dwarf, attr, DW_DLA_ATTR);
 497                 return (0);
 498         }
 499 
 500         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 501             "failed to get unsigned attribute for type: %s\n",
 502             dwarf_errmsg(derr));
 503         return (ECTF_CONVBKERR);
 504 }
 505 
 506 static int
 507 ctf_dwarf_unsigned(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Half name,
 508     Dwarf_Unsigned *valp)
 509 {
 510         int ret;
 511         Dwarf_Attribute attr;
 512         Dwarf_Error derr;
 513 
 514         if ((ret = ctf_dwarf_attribute(cup, die, name, &attr)) != 0)
 515                 return (ret);
 516 
 517         if (dwarf_formudata(attr, valp, &derr) == DW_DLV_OK) {
 518                 dwarf_dealloc(cup->cu_dwarf, attr, DW_DLA_ATTR);
 519                 return (0);
 520         }
 521 
 522         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 523             "failed to get unsigned attribute for type: %s\n",
 524             dwarf_errmsg(derr));
 525         return (ECTF_CONVBKERR);
 526 }
 527 
 528 static int
 529 ctf_dwarf_boolean(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Half name,
 530     Dwarf_Bool *val)
 531 {
 532         int ret;
 533         Dwarf_Attribute attr;
 534         Dwarf_Error derr;
 535 
 536         if ((ret = ctf_dwarf_attribute(cup, die, name, &attr)) != 0)
 537                 return (ret);
 538 
 539         if (dwarf_formflag(attr, val, &derr) == DW_DLV_OK) {
 540                 dwarf_dealloc(cup->cu_dwarf, attr, DW_DLA_ATTR);
 541                 return (0);
 542         }
 543 
 544         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 545             "failed to get boolean attribute for type: %s\n",
 546             dwarf_errmsg(derr));
 547 
 548         return (ECTF_CONVBKERR);
 549 }
 550 
 551 static int
 552 ctf_dwarf_string(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Half name, char **strp)
 553 {
 554         int ret;
 555         char *s;
 556         Dwarf_Attribute attr;
 557         Dwarf_Error derr;
 558 
 559         *strp = NULL;
 560         if ((ret = ctf_dwarf_attribute(cup, die, name, &attr)) != 0)
 561                 return (ret);
 562 
 563         if (dwarf_formstring(attr, &s, &derr) == DW_DLV_OK) {
 564                 if ((*strp = ctf_strdup(s)) == NULL)
 565                         ret = ENOMEM;
 566                 else
 567                         ret = 0;
 568                 dwarf_dealloc(cup->cu_dwarf, attr, DW_DLA_ATTR);
 569                 return (ret);
 570         }
 571 
 572         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 573             "failed to get string attribute for type: %s\n",
 574             dwarf_errmsg(derr));
 575         return (ECTF_CONVBKERR);
 576 }
 577 
 578 static int
 579 ctf_dwarf_member_location(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Unsigned *valp)
 580 {
 581         int ret;
 582         Dwarf_Error derr;
 583         Dwarf_Attribute attr;
 584         Dwarf_Locdesc *loc;
 585         Dwarf_Signed locnum;
 586 
 587         if ((ret = ctf_dwarf_attribute(cup, die, DW_AT_data_member_location,
 588             &attr)) != 0)
 589                 return (ret);
 590 
 591         if (dwarf_loclist(attr, &loc, &locnum, &derr) != DW_DLV_OK) {
 592                 (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 593                     "failed to obtain location list for member offset: %s",
 594                     dwarf_errmsg(derr));
 595                 dwarf_dealloc(cup->cu_dwarf, attr, DW_DLA_ATTR);
 596                 return (ECTF_CONVBKERR);
 597         }
 598         dwarf_dealloc(cup->cu_dwarf, attr, DW_DLA_ATTR);
 599 
 600         if (locnum != 1 || loc->ld_s->lr_atom != DW_OP_plus_uconst) {
 601                 (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 602                     "failed to parse location structure for member");
 603                 dwarf_dealloc(cup->cu_dwarf, loc->ld_s, DW_DLA_LOC_BLOCK);
 604                 dwarf_dealloc(cup->cu_dwarf, loc, DW_DLA_LOCDESC);
 605                 return (ECTF_CONVBKERR);
 606         }
 607 
 608         *valp = loc->ld_s->lr_number;
 609 
 610         dwarf_dealloc(cup->cu_dwarf, loc->ld_s, DW_DLA_LOC_BLOCK);
 611         dwarf_dealloc(cup->cu_dwarf, loc, DW_DLA_LOCDESC);
 612         return (0);
 613 }
 614 
 615 
 616 static int
 617 ctf_dwarf_offset(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Off *offsetp)
 618 {
 619         Dwarf_Error derr;
 620 
 621         if (dwarf_dieoffset(die, offsetp, &derr) == DW_DLV_OK)
 622                 return (0);
 623 
 624         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 625             "failed to get die offset: %s\n",
 626             dwarf_errmsg(derr));
 627         return (ECTF_CONVBKERR);
 628 }
 629 
 630 /* simpler variant for debugging output */
 631 static Dwarf_Off
 632 ctf_die_offset(Dwarf_Die die)
 633 {
 634         Dwarf_Off off = -1;
 635         Dwarf_Error derr;
 636 
 637         (void) dwarf_dieoffset(die, &off, &derr);
 638         return (off);
 639 }
 640 
 641 static int
 642 ctf_dwarf_tag(ctf_cu_t *cup, Dwarf_Die die, Dwarf_Half *tagp)
 643 {
 644         Dwarf_Error derr;
 645 
 646         if (dwarf_tag(die, tagp, &derr) == DW_DLV_OK)
 647                 return (0);
 648 
 649         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 650             "failed to get tag type: %s\n",
 651             dwarf_errmsg(derr));
 652         return (ECTF_CONVBKERR);
 653 }
 654 
 655 static int
 656 ctf_dwarf_sib(ctf_cu_t *cup, Dwarf_Die base, Dwarf_Die *sibp)
 657 {
 658         Dwarf_Error derr;
 659         int ret;
 660 
 661         *sibp = NULL;
 662         ret = dwarf_siblingof(cup->cu_dwarf, base, sibp, &derr);
 663         if (ret == DW_DLV_OK || ret == DW_DLV_NO_ENTRY)
 664                 return (0);
 665 
 666         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 667             "failed to sibling from die: %s\n",
 668             dwarf_errmsg(derr));
 669         return (ECTF_CONVBKERR);
 670 }
 671 
 672 static int
 673 ctf_dwarf_child(ctf_cu_t *cup, Dwarf_Die base, Dwarf_Die *childp)
 674 {
 675         Dwarf_Error derr;
 676         int ret;
 677 
 678         *childp = NULL;
 679         ret = dwarf_child(base, childp, &derr);
 680         if (ret == DW_DLV_OK || ret == DW_DLV_NO_ENTRY)
 681                 return (0);
 682 
 683         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 684             "failed to child from die: %s\n",
 685             dwarf_errmsg(derr));
 686         return (ECTF_CONVBKERR);
 687 }
 688 
 689 /*
 690  * Compilers disagree on what to do to determine if something has global
 691  * visiblity. Traditionally gcc has used DW_AT_external to indicate this while
 692  * Studio has used DW_AT_visibility. We check DW_AT_visibility first and then
 693  * fall back to DW_AT_external. Lack of DW_AT_external implies that it is not.
 694  */
 695 static int
 696 ctf_dwarf_isglobal(ctf_cu_t *cup, Dwarf_Die die, boolean_t *igp)
 697 {
 698         int ret;
 699         Dwarf_Signed vis;
 700         Dwarf_Bool ext;
 701 
 702         if ((ret = ctf_dwarf_signed(cup, die, DW_AT_visibility, &vis)) == 0) {
 703                 *igp = vis == DW_VIS_exported;
 704                 return (0);
 705         } else if (ret != ENOENT) {
 706                 return (ret);
 707         }
 708 
 709         if ((ret = ctf_dwarf_boolean(cup, die, DW_AT_external, &ext)) != 0) {
 710                 if (ret == ENOENT) {
 711                         *igp = B_FALSE;
 712                         return (0);
 713                 }
 714                 return (ret);
 715         }
 716         *igp = ext != 0 ? B_TRUE : B_FALSE;
 717         return (0);
 718 }
 719 
 720 static int
 721 ctf_dwarf_die_elfenc(Elf *elf, ctf_cu_t *cup, char *errbuf, size_t errlen)
 722 {
 723         GElf_Ehdr ehdr;
 724 
 725         if (gelf_getehdr(elf, &ehdr) == NULL) {
 726                 (void) snprintf(errbuf, errlen,
 727                     "failed to get ELF header: %s\n",
 728                     elf_errmsg(elf_errno()));
 729                 return (ECTF_CONVBKERR);
 730         }
 731 
 732         cup->cu_mach = ehdr.e_machine;
 733 
 734         if (ehdr.e_ident[EI_CLASS] == ELFCLASS32) {
 735                 cup->cu_ptrsz = 4;
 736                 VERIFY(ctf_setmodel(cup->cu_ctfp, CTF_MODEL_ILP32) == 0);
 737         } else if (ehdr.e_ident[EI_CLASS] == ELFCLASS64) {
 738                 cup->cu_ptrsz = 8;
 739                 VERIFY(ctf_setmodel(cup->cu_ctfp, CTF_MODEL_LP64) == 0);
 740         } else {
 741                 (void) snprintf(errbuf, errlen,
 742                     "unknown ELF class %d", ehdr.e_ident[EI_CLASS]);
 743                 return (ECTF_CONVBKERR);
 744         }
 745 
 746         if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB) {
 747                 cup->cu_bigend = B_FALSE;
 748         } else if (ehdr.e_ident[EI_DATA] == ELFDATA2MSB) {
 749                 cup->cu_bigend = B_TRUE;
 750         } else {
 751                 (void) snprintf(errbuf, errlen,
 752                     "unknown ELF data encoding: %hhu", ehdr.e_ident[EI_DATA]);
 753                 return (ECTF_CONVBKERR);
 754         }
 755 
 756         return (0);
 757 }
 758 
 759 typedef struct ctf_dwarf_fpent {
 760         size_t  cdfe_size;
 761         uint_t  cdfe_enc[3];
 762 } ctf_dwarf_fpent_t;
 763 
 764 typedef struct ctf_dwarf_fpmap {
 765         uint_t                  cdf_mach;
 766         ctf_dwarf_fpent_t       cdf_ents[4];
 767 } ctf_dwarf_fpmap_t;
 768 
 769 static const ctf_dwarf_fpmap_t ctf_dwarf_fpmaps[] = {
 770         { EM_SPARC, {
 771                 { 4, { CTF_FP_SINGLE, CTF_FP_CPLX, CTF_FP_IMAGRY } },
 772                 { 8, { CTF_FP_DOUBLE, CTF_FP_DCPLX, CTF_FP_DIMAGRY } },
 773                 { 16, { CTF_FP_LDOUBLE, CTF_FP_LDCPLX, CTF_FP_LDIMAGRY } },
 774                 { 0, { 0 } }
 775         } },
 776         { EM_SPARC32PLUS, {
 777                 { 4, { CTF_FP_SINGLE, CTF_FP_CPLX, CTF_FP_IMAGRY } },
 778                 { 8, { CTF_FP_DOUBLE, CTF_FP_DCPLX, CTF_FP_DIMAGRY } },
 779                 { 16, { CTF_FP_LDOUBLE, CTF_FP_LDCPLX, CTF_FP_LDIMAGRY } },
 780                 { 0, { 0 } }
 781         } },
 782         { EM_SPARCV9, {
 783                 { 4, { CTF_FP_SINGLE, CTF_FP_CPLX, CTF_FP_IMAGRY } },
 784                 { 8, { CTF_FP_DOUBLE, CTF_FP_DCPLX, CTF_FP_DIMAGRY } },
 785                 { 16, { CTF_FP_LDOUBLE, CTF_FP_LDCPLX, CTF_FP_LDIMAGRY } },
 786                 { 0, { 0 } }
 787         } },
 788         { EM_386, {
 789                 { 4, { CTF_FP_SINGLE, CTF_FP_CPLX, CTF_FP_IMAGRY } },
 790                 { 8, { CTF_FP_DOUBLE, CTF_FP_DCPLX, CTF_FP_DIMAGRY } },
 791                 { 12, { CTF_FP_LDOUBLE, CTF_FP_LDCPLX, CTF_FP_LDIMAGRY } },
 792                 { 0, { 0 } }
 793         } },
 794         { EM_X86_64, {
 795                 { 4, { CTF_FP_SINGLE, CTF_FP_CPLX, CTF_FP_IMAGRY } },
 796                 { 8, { CTF_FP_DOUBLE, CTF_FP_DCPLX, CTF_FP_DIMAGRY } },
 797                 { 16, { CTF_FP_LDOUBLE, CTF_FP_LDCPLX, CTF_FP_LDIMAGRY } },
 798                 { 0, { 0 } }
 799         } },
 800         { EM_NONE }
 801 };
 802 
 803 static int
 804 ctf_dwarf_float_base(ctf_cu_t *cup, Dwarf_Signed type, ctf_encoding_t *enc)
 805 {
 806         const ctf_dwarf_fpmap_t *map = &ctf_dwarf_fpmaps[0];
 807         const ctf_dwarf_fpent_t *ent;
 808         uint_t col = 0, mult = 1;
 809 
 810         for (map = &ctf_dwarf_fpmaps[0]; map->cdf_mach != EM_NONE; map++) {
 811                 if (map->cdf_mach == cup->cu_mach)
 812                         break;
 813         }
 814 
 815         if (map->cdf_mach == EM_NONE) {
 816                 (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 817                     "Unsupported machine type: %d\n", cup->cu_mach);
 818                 return (ENOTSUP);
 819         }
 820 
 821         if (type == DW_ATE_complex_float) {
 822                 mult = 2;
 823                 col = 1;
 824         } else if (type == DW_ATE_imaginary_float ||
 825             type == DW_ATE_SUN_imaginary_float) {
 826                 col = 2;
 827         }
 828 
 829         ent = &map->cdf_ents[0];
 830         for (ent = &map->cdf_ents[0]; ent->cdfe_size != 0; ent++) {
 831                 if (ent->cdfe_size * mult * 8 == enc->cte_bits) {
 832                         enc->cte_format = ent->cdfe_enc[col];
 833                         return (0);
 834                 }
 835         }
 836 
 837         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 838             "failed to find valid fp mapping for encoding %d, size %d bits\n",
 839             type, enc->cte_bits);
 840         return (EINVAL);
 841 }
 842 
 843 static int
 844 ctf_dwarf_dwarf_base(ctf_cu_t *cup, Dwarf_Die die, int *kindp,
 845     ctf_encoding_t *enc)
 846 {
 847         int ret;
 848         Dwarf_Signed type;
 849 
 850         if ((ret = ctf_dwarf_signed(cup, die, DW_AT_encoding, &type)) != 0)
 851                 return (ret);
 852 
 853         switch (type) {
 854         case DW_ATE_unsigned:
 855         case DW_ATE_address:
 856                 *kindp = CTF_K_INTEGER;
 857                 enc->cte_format = 0;
 858                 break;
 859         case DW_ATE_unsigned_char:
 860                 *kindp = CTF_K_INTEGER;
 861                 enc->cte_format = CTF_INT_CHAR;
 862                 break;
 863         case DW_ATE_signed:
 864                 *kindp = CTF_K_INTEGER;
 865                 enc->cte_format = CTF_INT_SIGNED;
 866                 break;
 867         case DW_ATE_signed_char:
 868                 *kindp = CTF_K_INTEGER;
 869                 enc->cte_format = CTF_INT_SIGNED | CTF_INT_CHAR;
 870                 break;
 871         case DW_ATE_boolean:
 872                 *kindp = CTF_K_INTEGER;
 873                 enc->cte_format = CTF_INT_SIGNED | CTF_INT_BOOL;
 874                 break;
 875         case DW_ATE_float:
 876         case DW_ATE_complex_float:
 877         case DW_ATE_imaginary_float:
 878         case DW_ATE_SUN_imaginary_float:
 879         case DW_ATE_SUN_interval_float:
 880                 *kindp = CTF_K_FLOAT;
 881                 if ((ret = ctf_dwarf_float_base(cup, type, enc)) != 0)
 882                         return (ret);
 883                 break;
 884         default:
 885                 (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
 886                     "encountered unkown DWARF encoding: %d", type);
 887                 return (ECTF_CONVBKERR);
 888         }
 889 
 890         return (0);
 891 }
 892 
 893 /*
 894  * Different compilers (at least GCC and Studio) use different names for types.
 895  * This parses the types and attempts to unify them. If this fails, we just fall
 896  * back to using the DWARF itself.
 897  */
 898 static int
 899 ctf_dwarf_parse_base(const char *name, int *kindp, ctf_encoding_t *enc,
 900     char **newnamep)
 901 {
 902         char buf[256];
 903         char *base, *c, *last;
 904         int nlong = 0, nshort = 0, nchar = 0, nint = 0;
 905         int sign = 1;
 906 
 907         if (strlen(name) + 1 > sizeof (buf))
 908                 return (EINVAL);
 909 
 910         (void) strlcpy(buf, name, sizeof (buf));
 911         for (c = strtok_r(buf, " ", &last); c != NULL;
 912             c = strtok_r(NULL, " ", &last)) {
 913                 if (strcmp(c, "signed") == 0) {
 914                         sign = 1;
 915                 } else if (strcmp(c, "unsigned") == 0) {
 916                         sign = 0;
 917                 } else if (strcmp(c, "long") == 0) {
 918                         nlong++;
 919                 } else if (strcmp(c, "char") == 0) {
 920                         nchar++;
 921                 } else if (strcmp(c, "short") == 0) {
 922                         nshort++;
 923                 } else if (strcmp(c, "int") == 0) {
 924                         nint++;
 925                 } else {
 926                         /*
 927                          * If we don't recognize any of the tokens, we'll tell
 928                          * the caller to fall back to the dwarf-provided
 929                          * encoding information.
 930                          */
 931                         return (EINVAL);
 932                 }
 933         }
 934 
 935         if (nchar > 1 || nshort > 1 || nint > 1 || nlong > 2)
 936                 return (EINVAL);
 937 
 938         if (nchar > 0) {
 939                 if (nlong > 0 || nshort > 0 || nint > 0)
 940                         return (EINVAL);
 941                 base = "char";
 942         } else if (nshort > 0) {
 943                 if (nlong > 0)
 944                         return (EINVAL);
 945                 base = "short";
 946         } else if (nlong > 0) {
 947                 base = "long";
 948         } else {
 949                 base = "int";
 950         }
 951 
 952         if (nchar > 0)
 953                 enc->cte_format = CTF_INT_CHAR;
 954         else
 955                 enc->cte_format = 0;
 956 
 957         if (sign > 0)
 958                 enc->cte_format |= CTF_INT_SIGNED;
 959 
 960         (void) snprintf(buf, sizeof (buf), "%s%s%s",
 961             (sign ? "" : "unsigned "),
 962             (nlong > 1 ? "long " : ""),
 963             base);
 964 
 965         *newnamep = ctf_strdup(buf);
 966         if (*newnamep == NULL)
 967                 return (ENOMEM);
 968         *kindp = CTF_K_INTEGER;
 969         return (0);
 970 }
 971 
 972 static int
 973 ctf_dwarf_create_base(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t *idp, int isroot,
 974     Dwarf_Off off)
 975 {
 976         int ret;
 977         char *name, *nname;
 978         Dwarf_Unsigned sz;
 979         int kind;
 980         ctf_encoding_t enc;
 981         ctf_id_t id;
 982 
 983         if ((ret = ctf_dwarf_string(cup, die, DW_AT_name, &name)) != 0)
 984                 return (ret);
 985         if ((ret = ctf_dwarf_unsigned(cup, die, DW_AT_byte_size, &sz)) != 0) {
 986                 goto out;
 987         }
 988         ctf_dprintf("Creating base type %s from off %llu, size: %d\n", name,
 989             off, sz);
 990 
 991         bzero(&enc, sizeof (ctf_encoding_t));
 992         enc.cte_bits = sz * 8;
 993         if ((ret = ctf_dwarf_parse_base(name, &kind, &enc, &nname)) == 0) {
 994                 ctf_free(name, strlen(name) + 1);
 995                 name = nname;
 996         } else {
 997                 if (ret != EINVAL)
 998                         return (ret);
 999                 ctf_dprintf("falling back to dwarf for base type %s\n", name);
1000                 if ((ret = ctf_dwarf_dwarf_base(cup, die, &kind, &enc)) != 0)
1001                         return (ret);
1002         }
1003 
1004         id = ctf_add_encoded(cup->cu_ctfp, isroot, name, &enc, kind);
1005         if (id == CTF_ERR) {
1006                 ret = ctf_errno(cup->cu_ctfp);
1007         } else {
1008                 *idp = id;
1009                 ret = ctf_dwmap_add(cup, id, die, B_FALSE);
1010         }
1011 out:
1012         ctf_free(name, strlen(name) + 1);
1013         return (ret);
1014 }
1015 
1016 /*
1017  * Getting a member's offset is a surprisingly intricate dance. It works as
1018  * follows:
1019  *
1020  * 1) If we're in DWARFv4, then we either have a DW_AT_data_bit_offset or we
1021  * have a DW_AT_data_member_location. We won't have both. Thus we check first
1022  * for DW_AT_data_bit_offset, and if it exists, we're set.
1023  *
1024  * Next, if we have a bitfield and we don't have a DW_AT_data_bit_offset, then
1025  * we have to grab the data location and use the following dance:
1026  *
1027  * 2) Gather the set of DW_AT_byte_size, DW_AT_bit_offset, and DW_AT_bit_size.
1028  * Of course, the DW_AT_byte_size may be omitted, even though it isn't always.
1029  * When it's been omitted, we then have to say that the size is that of the
1030  * underlying type, which forces that to be after a ctf_update(). Here, we have
1031  * to do different things based on whether or not we're using big endian or
1032  * little endian to obtain the proper offset.
1033  */
1034 static int
1035 ctf_dwarf_member_offset(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t mid,
1036     ulong_t *offp)
1037 {
1038         int ret;
1039         Dwarf_Unsigned loc, bitsz, bytesz;
1040         Dwarf_Signed bitoff;
1041         size_t off;
1042         ssize_t tsz;
1043 
1044         if ((ret = ctf_dwarf_unsigned(cup, die, DW_AT_data_bit_offset,
1045             &loc)) == 0) {
1046                 *offp = loc;
1047                 return (0);
1048         } else if (ret != ENOENT) {
1049                 return (ret);
1050         }
1051 
1052         if ((ret = ctf_dwarf_member_location(cup, die, &loc)) != 0)
1053                 return (ret);
1054         off = loc * 8;
1055 
1056         if ((ret = ctf_dwarf_signed(cup, die, DW_AT_bit_offset,
1057             &bitoff)) != 0) {
1058                 if (ret != ENOENT)
1059                         return (ret);
1060                 *offp = off;
1061                 return (0);
1062         }
1063 
1064         /* At this point we have to have DW_AT_bit_size */
1065         if ((ret = ctf_dwarf_unsigned(cup, die, DW_AT_bit_size, &bitsz)) != 0)
1066                 return (ret);
1067 
1068         if ((ret = ctf_dwarf_unsigned(cup, die, DW_AT_byte_size,
1069             &bytesz)) != 0) {
1070                 if (ret != ENOENT)
1071                         return (ret);
1072                 if ((tsz = ctf_type_size(cup->cu_ctfp, mid)) == CTF_ERR) {
1073                         int e = ctf_errno(cup->cu_ctfp);
1074                         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
1075                             "failed to get type size: %s", ctf_errmsg(e));
1076                         return (ECTF_CONVBKERR);
1077                 }
1078         } else {
1079                 tsz = bytesz;
1080         }
1081         tsz *= 8;
1082         if (cup->cu_bigend == B_TRUE) {
1083                 *offp = off + bitoff;
1084         } else {
1085                 *offp = off + tsz - bitoff - bitsz;
1086         }
1087 
1088         return (0);
1089 }
1090 
1091 /*
1092  * We need to determine if the member in question is a bitfield. If it is, then
1093  * we need to go through and create a new type that's based on the actual base
1094  * type, but has a different size. We also rename the type as a result to help
1095  * deal with future collisions.
1096  *
1097  * Here we need to look and see if we have a DW_AT_bit_size value. If we have a
1098  * bit size member and it does not equal the byte size member, then we need to
1099  * create a bitfield type based on this.
1100  *
1101  * Note: When we support DWARFv4, there may be a chance that we need to also
1102  * search for the DW_AT_byte_size if we don't have a DW_AT_bit_size member.
1103  */
1104 static int
1105 ctf_dwarf_member_bitfield(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t *idp)
1106 {
1107         int ret;
1108         Dwarf_Unsigned bitsz;
1109         ctf_encoding_t e;
1110         ctf_dwbitf_t *cdb;
1111         ctf_dtdef_t *dtd;
1112         ctf_id_t base = *idp;
1113         int kind;
1114 
1115         if ((ret = ctf_dwarf_unsigned(cup, die, DW_AT_bit_size, &bitsz)) != 0) {
1116                 if (ret == ENOENT)
1117                         return (0);
1118                 return (ret);
1119         }
1120 
1121         ctf_dprintf("Trying to deal with bitfields on %d:%d\n", base, bitsz);
1122         /*
1123          * Given that we now have a bitsize, time to go do something about it.
1124          * We're going to create a new type based on the current one, but first
1125          * we need to find the base type. This means we need to traverse any
1126          * typedef's, consts, and volatiles until we get to what should be
1127          * something of type integer or enumeration.
1128          */
1129         VERIFY(bitsz < UINT32_MAX);
1130         dtd = ctf_dtd_lookup(cup->cu_ctfp, base);
1131         VERIFY(dtd != NULL);
1132         kind = CTF_INFO_KIND(dtd->dtd_data.ctt_info);
1133         while (kind == CTF_K_TYPEDEF || kind == CTF_K_CONST ||
1134             kind == CTF_K_VOLATILE) {
1135                 dtd = ctf_dtd_lookup(cup->cu_ctfp, dtd->dtd_data.ctt_type);
1136                 VERIFY(dtd != NULL);
1137                 kind = CTF_INFO_KIND(dtd->dtd_data.ctt_info);
1138         }
1139         ctf_dprintf("got kind %d\n", kind);
1140         VERIFY(kind == CTF_K_INTEGER || kind == CTF_K_ENUM);
1141 
1142         /*
1143          * As surprising as it may be, it is strictly possible to create a
1144          * bitfield that is based on an enum. Of course, the C standard leaves
1145          * enums sizing as an ABI concern more or less. To that effect, today on
1146          * all illumos platforms the size of an enum is generally that of an
1147          * int as our supported data models and ABIs all agree on that. So what
1148          * we'll do is fake up a CTF encoding here to use. In this case, we'll
1149          * treat it as an unsigned value of whatever size the underlying enum
1150          * currently has (which is in the ctt_size member of its dynamic type
1151          * data).
1152          */
1153         if (kind == CTF_K_INTEGER) {
1154                 e = dtd->dtd_u.dtu_enc;
1155         } else {
1156                 bzero(&e, sizeof (ctf_encoding_t));
1157                 e.cte_bits = dtd->dtd_data.ctt_size * NBBY;
1158         }
1159 
1160         for (cdb = ctf_list_next(&cup->cu_bitfields); cdb != NULL;
1161             cdb = ctf_list_next(cdb)) {
1162                 if (cdb->cdb_base == base && cdb->cdb_nbits == bitsz)
1163                         break;
1164         }
1165 
1166         /*
1167          * Create a new type if none exists. We name all types in a way that is
1168          * guaranteed not to conflict with the corresponding C type. We do this
1169          * by using the ':' operator.
1170          */
1171         if (cdb == NULL) {
1172                 size_t namesz;
1173                 char *name;
1174 
1175                 e.cte_bits = bitsz;
1176                 namesz = snprintf(NULL, 0, "%s:%d", dtd->dtd_name,
1177                     (uint32_t)bitsz);
1178                 name = ctf_alloc(namesz + 1);
1179                 if (name == NULL)
1180                         return (ENOMEM);
1181                 cdb = ctf_alloc(sizeof (ctf_dwbitf_t));
1182                 if (cdb == NULL) {
1183                         ctf_free(name, namesz + 1);
1184                         return (ENOMEM);
1185                 }
1186                 (void) snprintf(name, namesz + 1, "%s:%d", dtd->dtd_name,
1187                     (uint32_t)bitsz);
1188 
1189                 cdb->cdb_base = base;
1190                 cdb->cdb_nbits = bitsz;
1191                 cdb->cdb_id = ctf_add_integer(cup->cu_ctfp, CTF_ADD_NONROOT,
1192                     name, &e);
1193                 if (cdb->cdb_id == CTF_ERR) {
1194                         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
1195                             "failed to get add bitfield type %s: %s", name,
1196                             ctf_errmsg(ctf_errno(cup->cu_ctfp)));
1197                         ctf_free(name, namesz + 1);
1198                         ctf_free(cdb, sizeof (ctf_dwbitf_t));
1199                         return (ECTF_CONVBKERR);
1200                 }
1201                 ctf_free(name, namesz + 1);
1202                 ctf_list_append(&cup->cu_bitfields, cdb);
1203         }
1204 
1205         *idp = cdb->cdb_id;
1206 
1207         return (0);
1208 }
1209 
1210 static int
1211 ctf_dwarf_fixup_sou(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t base, boolean_t add)
1212 {
1213         int ret, kind;
1214         Dwarf_Die child, memb;
1215         Dwarf_Unsigned size;
1216         ulong_t nsz;
1217 
1218         kind = ctf_type_kind(cup->cu_ctfp, base);
1219         VERIFY(kind != CTF_ERR);
1220         VERIFY(kind == CTF_K_STRUCT || kind == CTF_K_UNION);
1221 
1222         /*
1223          * Members are in children. However, gcc also allows empty ones.
1224          */
1225         if ((ret = ctf_dwarf_child(cup, die, &child)) != 0)
1226                 return (ret);
1227         if (child == NULL)
1228                 return (0);
1229 
1230         memb = child;
1231         while (memb != NULL) {
1232                 Dwarf_Die sib, tdie;
1233                 Dwarf_Half tag;
1234                 ctf_id_t mid;
1235                 char *mname;
1236                 ulong_t memboff = 0;
1237 
1238                 if ((ret = ctf_dwarf_tag(cup, memb, &tag)) != 0)
1239                         return (ret);
1240 
1241                 if (tag != DW_TAG_member)
1242                         continue;
1243 
1244                 if ((ret = ctf_dwarf_refdie(cup, memb, DW_AT_type, &tdie)) != 0)
1245                         return (ret);
1246 
1247                 if ((ret = ctf_dwarf_convert_type(cup, tdie, &mid,
1248                     CTF_ADD_NONROOT)) != 0)
1249                         return (ret);
1250                 ctf_dprintf("Got back type id: %d\n", mid);
1251 
1252                 /*
1253                  * If we're not adding a member, just go ahead and return.
1254                  */
1255                 if (add == B_FALSE) {
1256                         if ((ret = ctf_dwarf_member_bitfield(cup, memb,
1257                             &mid)) != 0)
1258                                 return (ret);
1259                         goto next;
1260                 }
1261 
1262                 if ((ret = ctf_dwarf_string(cup, memb, DW_AT_name,
1263                     &mname)) != 0 && ret != ENOENT)
1264                         return (ret);
1265                 if (ret == ENOENT)
1266                         mname = NULL;
1267 
1268                 if (kind == CTF_K_UNION) {
1269                         memboff = 0;
1270                 } else if ((ret = ctf_dwarf_member_offset(cup, memb, mid,
1271                     &memboff)) != 0) {
1272                         if (mname != NULL)
1273                                 ctf_free(mname, strlen(mname) + 1);
1274                         return (ret);
1275                 }
1276 
1277                 if ((ret = ctf_dwarf_member_bitfield(cup, memb, &mid)) != 0)
1278                         return (ret);
1279 
1280                 ret = ctf_add_member(cup->cu_ctfp, base, mname, mid, memboff);
1281                 if (ret == CTF_ERR) {
1282                         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
1283                             "failed to add member %s: %s",
1284                             mname, ctf_errmsg(ctf_errno(cup->cu_ctfp)));
1285                         if (mname != NULL)
1286                                 ctf_free(mname, strlen(mname) + 1);
1287                         return (ECTF_CONVBKERR);
1288                 }
1289 
1290                 if (mname != NULL)
1291                         ctf_free(mname, strlen(mname) + 1);
1292 
1293 next:
1294                 if ((ret = ctf_dwarf_sib(cup, memb, &sib)) != 0)
1295                         return (ret);
1296                 memb = sib;
1297         }
1298 
1299         /*
1300          * If we're not adding members, then we don't know the final size of the
1301          * structure, so end here.
1302          */
1303         if (add == B_FALSE)
1304                 return (0);
1305 
1306         /* Finally set the size of the structure to the actual byte size */
1307         if ((ret = ctf_dwarf_unsigned(cup, die, DW_AT_byte_size, &size)) != 0)
1308                 return (ret);
1309         nsz = size;
1310         if ((ctf_set_size(cup->cu_ctfp, base, nsz)) == CTF_ERR) {
1311                 int e = ctf_errno(cup->cu_ctfp);
1312                 (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
1313                     "failed to set type size for %d to 0x%x: %s", base,
1314                     (uint32_t)size, ctf_errmsg(e));
1315                 return (ECTF_CONVBKERR);
1316         }
1317 
1318         return (0);
1319 }
1320 
1321 static int
1322 ctf_dwarf_create_sou(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t *idp,
1323     int kind, int isroot)
1324 {
1325         int ret;
1326         char *name;
1327         ctf_id_t base;
1328         Dwarf_Die child;
1329         Dwarf_Bool decl;
1330 
1331         /*
1332          * Deal with the terribly annoying case of anonymous structs and unions.
1333          * If they don't have a name, set the name to the empty string.
1334          */
1335         if ((ret = ctf_dwarf_string(cup, die, DW_AT_name, &name)) != 0 &&
1336             ret != ENOENT)
1337                 return (ret);
1338         if (ret == ENOENT)
1339                 name = NULL;
1340 
1341         /*
1342          * We need to check if we just have a declaration here. If we do, then
1343          * instead of creating an actual structure or union, we're just going to
1344          * go ahead and create a forward. During a dedup or merge, the forward
1345          * will be replaced with the real thing.
1346          */
1347         if ((ret = ctf_dwarf_boolean(cup, die, DW_AT_declaration,
1348             &decl)) != 0) {
1349                 if (ret != ENOENT)
1350                         return (ret);
1351                 decl = 0;
1352         }
1353 
1354         if (decl != 0) {
1355                 base = ctf_add_forward(cup->cu_ctfp, isroot, name, kind);
1356         } else if (kind == CTF_K_STRUCT) {
1357                 base = ctf_add_struct(cup->cu_ctfp, isroot, name);
1358         } else {
1359                 base = ctf_add_union(cup->cu_ctfp, isroot, name);
1360         }
1361         ctf_dprintf("added sou %s (%d) (%d)\n", name, kind, base);
1362         if (name != NULL)
1363                 ctf_free(name, strlen(name) + 1);
1364         if (base == CTF_ERR)
1365                 return (ctf_errno(cup->cu_ctfp));
1366         *idp = base;
1367 
1368         /*
1369          * If it's just a declaration, we're not going to mark it for fix up or
1370          * do anything else.
1371          */
1372         if (decl == B_TRUE)
1373                 return (ctf_dwmap_add(cup, base, die, B_FALSE));
1374         if ((ret = ctf_dwmap_add(cup, base, die, B_TRUE)) != 0)
1375                 return (ret);
1376 
1377         /*
1378          * Members are in children. However, gcc also allows empty ones.
1379          */
1380         if ((ret = ctf_dwarf_child(cup, die, &child)) != 0)
1381                 return (ret);
1382         if (child == NULL)
1383                 return (0);
1384 
1385         return (0);
1386 }
1387 
1388 static int
1389 ctf_dwarf_create_array_range(ctf_cu_t *cup, Dwarf_Die range, ctf_id_t *idp,
1390     ctf_id_t base, int isroot)
1391 {
1392         int ret;
1393         Dwarf_Die sib;
1394         Dwarf_Unsigned val;
1395         Dwarf_Signed sval;
1396         ctf_arinfo_t ar;
1397 
1398         ctf_dprintf("creating array range\n");
1399 
1400         if ((ret = ctf_dwarf_sib(cup, range, &sib)) != 0)
1401                 return (ret);
1402         if (sib != NULL) {
1403                 ctf_id_t id;
1404                 if ((ret = ctf_dwarf_create_array_range(cup, sib, &id,
1405                     base, CTF_ADD_NONROOT)) != 0)
1406                         return (ret);
1407                 ar.ctr_contents = id;
1408         } else {
1409                 ar.ctr_contents = base;
1410         }
1411 
1412         if ((ar.ctr_index = ctf_dwarf_long(cup)) == CTF_ERR)
1413                 return (ctf_errno(cup->cu_ctfp));
1414 
1415         /*
1416          * Array bounds can be signed or unsigned, but there are several kinds
1417          * of signless forms (data1, data2, etc) that take their sign from the
1418          * routine that is trying to interpret them.  That is, data1 can be
1419          * either signed or unsigned, depending on whether you use the signed or
1420          * unsigned accessor function.  GCC will use the signless forms to store
1421          * unsigned values which have their high bit set, so we need to try to
1422          * read them first as unsigned to get positive values.  We could also
1423          * try signed first, falling back to unsigned if we got a negative
1424          * value.
1425          */
1426         if ((ret = ctf_dwarf_unsigned(cup, range, DW_AT_upper_bound,
1427             &val)) == 0) {
1428                 ar.ctr_nelems = val + 1;
1429         } else if (ret != ENOENT) {
1430                 return (ret);
1431         } else if ((ret = ctf_dwarf_signed(cup, range, DW_AT_upper_bound,
1432             &sval)) == 0) {
1433                 ar.ctr_nelems = sval + 1;
1434         } else if (ret != ENOENT) {
1435                 return (ret);
1436         } else {
1437                 ar.ctr_nelems = 0;
1438         }
1439 
1440         if ((*idp = ctf_add_array(cup->cu_ctfp, isroot, &ar)) == CTF_ERR)
1441                 return (ctf_errno(cup->cu_ctfp));
1442 
1443         return (0);
1444 }
1445 
1446 /*
1447  * Try and create an array type. First, the kind of the array is specified in
1448  * the DW_AT_type entry. Next, the number of entries is stored in a more
1449  * complicated form, we should have a child that has the DW_TAG_subrange type.
1450  */
1451 static int
1452 ctf_dwarf_create_array(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t *idp, int isroot)
1453 {
1454         int ret;
1455         Dwarf_Die tdie, rdie;
1456         ctf_id_t tid;
1457         Dwarf_Half rtag;
1458 
1459         if ((ret = ctf_dwarf_refdie(cup, die, DW_AT_type, &tdie)) != 0)
1460                 return (ret);
1461         if ((ret = ctf_dwarf_convert_type(cup, tdie, &tid,
1462             CTF_ADD_NONROOT)) != 0)
1463                 return (ret);
1464 
1465         if ((ret = ctf_dwarf_child(cup, die, &rdie)) != 0)
1466                 return (ret);
1467         if ((ret = ctf_dwarf_tag(cup, rdie, &rtag)) != 0)
1468                 return (ret);
1469         if (rtag != DW_TAG_subrange_type) {
1470                 (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
1471                     "encountered array without DW_TAG_subrange_type child\n");
1472                 return (ECTF_CONVBKERR);
1473         }
1474 
1475         /*
1476          * The compiler may opt to describe a multi-dimensional array as one
1477          * giant array or it may opt to instead encode it as a series of
1478          * subranges. If it's the latter, then for each subrange we introduce a
1479          * type. We can always use the base type.
1480          */
1481         if ((ret = ctf_dwarf_create_array_range(cup, rdie, idp, tid,
1482             isroot)) != 0)
1483                 return (ret);
1484         ctf_dprintf("Got back id %d\n", *idp);
1485         return (ctf_dwmap_add(cup, *idp, die, B_FALSE));
1486 }
1487 
1488 static int
1489 ctf_dwarf_create_reference(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t *idp,
1490     int kind, int isroot)
1491 {
1492         int ret;
1493         ctf_id_t id;
1494         Dwarf_Die tdie;
1495         char *name;
1496         size_t namelen;
1497 
1498         if ((ret = ctf_dwarf_string(cup, die, DW_AT_name, &name)) != 0 &&
1499             ret != ENOENT)
1500                 return (ret);
1501         if (ret == ENOENT) {
1502                 name = NULL;
1503                 namelen = 0;
1504         } else {
1505                 namelen = strlen(name);
1506         }
1507 
1508         ctf_dprintf("reference kind %d %s\n", kind, name != NULL ? name : "<>");
1509 
1510         if ((ret = ctf_dwarf_refdie(cup, die, DW_AT_type, &tdie)) != 0) {
1511                 if (ret != ENOENT) {
1512                         ctf_free(name, namelen);
1513                         return (ret);
1514                 }
1515                 if ((id = ctf_dwarf_void(cup)) == CTF_ERR) {
1516                         ctf_free(name, namelen);
1517                         return (ctf_errno(cup->cu_ctfp));
1518                 }
1519         } else {
1520                 if ((ret = ctf_dwarf_convert_type(cup, tdie, &id,
1521                     CTF_ADD_NONROOT)) != 0) {
1522                         ctf_free(name, namelen);
1523                         return (ret);
1524                 }
1525         }
1526 
1527         if ((*idp = ctf_add_reftype(cup->cu_ctfp, isroot, name, id, kind)) ==
1528             CTF_ERR) {
1529                 ctf_free(name, namelen);
1530                 return (ctf_errno(cup->cu_ctfp));
1531         }
1532 
1533         ctf_free(name, namelen);
1534         return (ctf_dwmap_add(cup, *idp, die, B_FALSE));
1535 }
1536 
1537 static int
1538 ctf_dwarf_create_enum(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t *idp, int isroot)
1539 {
1540         int ret;
1541         ctf_id_t id;
1542         Dwarf_Die child;
1543         char *name;
1544 
1545         if ((ret = ctf_dwarf_string(cup, die, DW_AT_name, &name)) != 0 &&
1546             ret != ENOENT)
1547                 return (ret);
1548         if (ret == ENOENT)
1549                 name = NULL;
1550         id = ctf_add_enum(cup->cu_ctfp, isroot, name);
1551         ctf_dprintf("added enum %s (%d)\n", name, id);
1552         if (name != NULL)
1553                 ctf_free(name, strlen(name) + 1);
1554         if (id == CTF_ERR)
1555                 return (ctf_errno(cup->cu_ctfp));
1556         *idp = id;
1557         if ((ret = ctf_dwmap_add(cup, id, die, B_FALSE)) != 0)
1558                 return (ret);
1559 
1560         if ((ret = ctf_dwarf_child(cup, die, &child)) != 0) {
1561                 if (ret == ENOENT)
1562                         ret = 0;
1563                 return (ret);
1564         }
1565 
1566         while (child != NULL) {
1567                 Dwarf_Half tag;
1568                 Dwarf_Signed sval;
1569                 Dwarf_Unsigned uval;
1570                 Dwarf_Die arg = child;
1571                 int eval;
1572 
1573                 if ((ret = ctf_dwarf_sib(cup, arg, &child)) != 0)
1574                         return (ret);
1575 
1576                 if ((ret = ctf_dwarf_tag(cup, arg, &tag)) != 0)
1577                         return (ret);
1578 
1579                 if (tag != DW_TAG_enumerator) {
1580                         if ((ret = ctf_dwarf_convert_type(cup, arg, NULL,
1581                             CTF_ADD_NONROOT)) != 0)
1582                                 return (ret);
1583                         continue;
1584                 }
1585 
1586                 /*
1587                  * DWARF v4 section 5.7 tells us we'll always have names.
1588                  */
1589                 if ((ret = ctf_dwarf_string(cup, arg, DW_AT_name, &name)) != 0)
1590                         return (ret);
1591 
1592                 /*
1593                  * We have to be careful here: newer GCCs generate DWARF where
1594                  * an unsigned value will happily pass ctf_dwarf_signed().
1595                  * Since negative values will fail ctf_dwarf_unsigned(), we try
1596                  * that first to make sure we get the right value.
1597                  */
1598                 if ((ret = ctf_dwarf_unsigned(cup, arg, DW_AT_const_value,
1599                     &uval)) == 0) {
1600                         eval = (int)uval;
1601                 } else if ((ret = ctf_dwarf_signed(cup, arg, DW_AT_const_value,
1602                     &sval)) == 0) {
1603                         eval = sval;
1604                 }
1605 
1606                 if (ret != 0) {
1607                         if (ret != ENOENT)
1608                                 return (ret);
1609 
1610                         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
1611                             "encountered enumeration without constant value\n");
1612                         return (ECTF_CONVBKERR);
1613                 }
1614 
1615                 ret = ctf_add_enumerator(cup->cu_ctfp, id, name, eval);
1616                 if (ret == CTF_ERR) {
1617                         (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
1618                             "failed to add enumarator %s (%d) to %d\n",
1619                             name, eval, id);
1620                         ctf_free(name, strlen(name) + 1);
1621                         return (ctf_errno(cup->cu_ctfp));
1622                 }
1623                 ctf_free(name, strlen(name) + 1);
1624         }
1625 
1626         return (0);
1627 }
1628 
1629 /*
1630  * For a function pointer, walk over and process all of its children, unless we
1631  * encounter one that's just a declaration. In which case, we error on it.
1632  */
1633 static int
1634 ctf_dwarf_create_fptr(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t *idp, int isroot)
1635 {
1636         int ret;
1637         Dwarf_Bool b;
1638         ctf_funcinfo_t fi;
1639         Dwarf_Die retdie;
1640         ctf_id_t *argv = NULL;
1641 
1642         bzero(&fi, sizeof (ctf_funcinfo_t));
1643 
1644         if ((ret = ctf_dwarf_boolean(cup, die, DW_AT_declaration, &b)) != 0) {
1645                 if (ret != ENOENT)
1646                         return (ret);
1647         } else {
1648                 if (b != 0)
1649                         return (EPROTOTYPE);
1650         }
1651 
1652         /*
1653          * Return type is in DW_AT_type, if none, it returns void.
1654          */
1655         if ((ret = ctf_dwarf_refdie(cup, die, DW_AT_type, &retdie)) != 0) {
1656                 if (ret != ENOENT)
1657                         return (ret);
1658                 if ((fi.ctc_return = ctf_dwarf_void(cup)) == CTF_ERR)
1659                         return (ctf_errno(cup->cu_ctfp));
1660         } else {
1661                 if ((ret = ctf_dwarf_convert_type(cup, retdie, &fi.ctc_return,
1662                     CTF_ADD_NONROOT)) != 0)
1663                         return (ret);
1664         }
1665 
1666         if ((ret = ctf_dwarf_function_count(cup, die, &fi, B_TRUE)) != 0) {
1667                 return (ret);
1668         }
1669 
1670         if (fi.ctc_argc != 0) {
1671                 argv = ctf_alloc(sizeof (ctf_id_t) * fi.ctc_argc);
1672                 if (argv == NULL)
1673                         return (ENOMEM);
1674 
1675                 if ((ret = ctf_dwarf_convert_fargs(cup, die, &fi, argv)) != 0) {
1676                         ctf_free(argv, sizeof (ctf_id_t) * fi.ctc_argc);
1677                         return (ret);
1678                 }
1679         }
1680 
1681         if ((*idp = ctf_add_funcptr(cup->cu_ctfp, isroot, &fi, argv)) ==
1682             CTF_ERR) {
1683                 ctf_free(argv, sizeof (ctf_id_t) * fi.ctc_argc);
1684                 return (ctf_errno(cup->cu_ctfp));
1685         }
1686 
1687         ctf_free(argv, sizeof (ctf_id_t) * fi.ctc_argc);
1688         return (ctf_dwmap_add(cup, *idp, die, B_FALSE));
1689 }
1690 
1691 static int
1692 ctf_dwarf_convert_type(ctf_cu_t *cup, Dwarf_Die die, ctf_id_t *idp,
1693     int isroot)
1694 {
1695         int ret;
1696         Dwarf_Off offset;
1697         Dwarf_Half tag;
1698         ctf_dwmap_t lookup, *map;
1699         ctf_id_t id;
1700 
1701         if (idp == NULL)
1702                 idp = &id;
1703 
1704         if ((ret = ctf_dwarf_offset(cup, die, &offset)) != 0)
1705                 return (ret);
1706 
1707         if (offset > cup->cu_maxoff) {
1708                 (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
1709                     "die offset %llu beyond maximum for header %llu\n",
1710                     offset, cup->cu_maxoff);
1711                 return (ECTF_CONVBKERR);
1712         }
1713 
1714         /*
1715          * If we've already added an entry for this offset, then we're done.
1716          */
1717         lookup.cdm_off = offset;
1718         if ((map = avl_find(&cup->cu_map, &lookup, NULL)) != NULL) {
1719                 *idp = map->cdm_id;
1720                 return (0);
1721         }
1722 
1723         if ((ret = ctf_dwarf_tag(cup, die, &tag)) != 0)
1724                 return (ret);
1725 
1726         ret = ENOTSUP;
1727         switch (tag) {
1728         case DW_TAG_base_type:
1729                 ctf_dprintf("base\n");
1730                 ret = ctf_dwarf_create_base(cup, die, idp, isroot, offset);
1731                 break;
1732         case DW_TAG_array_type:
1733                 ctf_dprintf("array\n");
1734                 ret = ctf_dwarf_create_array(cup, die, idp, isroot);
1735                 break;
1736         case DW_TAG_enumeration_type:
1737                 ctf_dprintf("enum\n");
1738                 ret = ctf_dwarf_create_enum(cup, die, idp, isroot);
1739                 break;
1740         case DW_TAG_pointer_type:
1741                 ctf_dprintf("pointer\n");
1742                 ret = ctf_dwarf_create_reference(cup, die, idp, CTF_K_POINTER,
1743                     isroot);
1744                 break;
1745         case DW_TAG_structure_type:
1746                 ctf_dprintf("struct\n");
1747                 ret = ctf_dwarf_create_sou(cup, die, idp, CTF_K_STRUCT,
1748                     isroot);
1749                 break;
1750         case DW_TAG_subroutine_type:
1751                 ctf_dprintf("fptr\n");
1752                 ret = ctf_dwarf_create_fptr(cup, die, idp, isroot);
1753                 break;
1754         case DW_TAG_typedef:
1755                 ctf_dprintf("typedef\n");
1756                 ret = ctf_dwarf_create_reference(cup, die, idp, CTF_K_TYPEDEF,
1757                     isroot);
1758                 break;
1759         case DW_TAG_union_type:
1760                 ctf_dprintf("union\n");
1761                 ret = ctf_dwarf_create_sou(cup, die, idp, CTF_K_UNION,
1762                     isroot);
1763                 break;
1764         case DW_TAG_const_type:
1765                 ctf_dprintf("const\n");
1766                 ret = ctf_dwarf_create_reference(cup, die, idp, CTF_K_CONST,
1767                     isroot);
1768                 break;
1769         case DW_TAG_volatile_type:
1770                 ctf_dprintf("volatile\n");
1771                 ret = ctf_dwarf_create_reference(cup, die, idp, CTF_K_VOLATILE,
1772                     isroot);
1773                 break;
1774         case DW_TAG_restrict_type:
1775                 ctf_dprintf("restrict\n");
1776                 ret = ctf_dwarf_create_reference(cup, die, idp, CTF_K_RESTRICT,
1777                     isroot);
1778                 break;
1779         default:
1780                 ctf_dprintf("ignoring tag type %x\n", tag);
1781                 ret = 0;
1782                 break;
1783         }
1784         ctf_dprintf("ctf_dwarf_convert_type tag specific handler returned %d\n",
1785             ret);
1786 
1787         return (ret);
1788 }
1789 
1790 static int
1791 ctf_dwarf_walk_lexical(ctf_cu_t *cup, Dwarf_Die die)
1792 {
1793         int ret;
1794         Dwarf_Die child;
1795 
1796         if ((ret = ctf_dwarf_child(cup, die, &child)) != 0)
1797                 return (ret);
1798 
1799         if (child == NULL)
1800                 return (0);
1801 
1802         return (ctf_dwarf_convert_die(cup, die));
1803 }
1804 
1805 static int
1806 ctf_dwarf_function_count(ctf_cu_t *cup, Dwarf_Die die, ctf_funcinfo_t *fip,
1807     boolean_t fptr)
1808 {
1809         int ret;
1810         Dwarf_Die child, sib, arg;
1811 
1812         if ((ret = ctf_dwarf_child(cup, die, &child)) != 0)
1813                 return (ret);
1814 
1815         arg = child;
1816         while (arg != NULL) {
1817                 Dwarf_Half tag;
1818 
1819                 if ((ret = ctf_dwarf_tag(cup, arg, &tag)) != 0)
1820                         return (ret);
1821 
1822                 /*
1823                  * We have to check for a varargs type decleration. This will
1824                  * happen in one of two ways. If we have a function pointer
1825                  * type, then it'll be done with a tag of type
1826                  * DW_TAG_unspecified_parameters. However, it only means we have
1827                  * a variable number of arguments, if we have more than one
1828                  * argument found so far. Otherwise, when we have a function
1829                  * type, it instead uses a formal parameter whose name is '...'
1830                  * to indicate a variable arguments member.
1831                  *
1832                  * Also, if we have a function pointer, then we have to expect
1833                  * that we might not get a name at all.
1834                  */
1835                 if (tag == DW_TAG_formal_parameter && fptr == B_FALSE) {
1836                         char *name;
1837                         if ((ret = ctf_dwarf_string(cup, die, DW_AT_name,
1838                             &name)) != 0)
1839                                 return (ret);
1840                         if (strcmp(name, DWARF_VARARGS_NAME) == 0)
1841                                 fip->ctc_flags |= CTF_FUNC_VARARG;
1842                         else
1843                                 fip->ctc_argc++;
1844                         ctf_free(name, strlen(name) + 1);
1845                 } else if (tag == DW_TAG_formal_parameter) {
1846                         fip->ctc_argc++;
1847                 } else if (tag == DW_TAG_unspecified_parameters &&
1848                     fip->ctc_argc > 0) {
1849                         fip->ctc_flags |= CTF_FUNC_VARARG;
1850                 }
1851                 if ((ret = ctf_dwarf_sib(cup, arg, &sib)) != 0)
1852                         return (ret);
1853                 arg = sib;
1854         }
1855 
1856         return (0);
1857 }
1858 
1859 static int
1860 ctf_dwarf_convert_fargs(ctf_cu_t *cup, Dwarf_Die die, ctf_funcinfo_t *fip,
1861     ctf_id_t *argv)
1862 {
1863         int ret;
1864         int i = 0;
1865         Dwarf_Die child, sib, arg;
1866 
1867         if ((ret = ctf_dwarf_child(cup, die, &child)) != 0)
1868                 return (ret);
1869 
1870         arg = child;
1871         while (arg != NULL) {
1872                 Dwarf_Half tag;
1873 
1874                 if ((ret = ctf_dwarf_tag(cup, arg, &tag)) != 0)
1875                         return (ret);
1876                 if (tag == DW_TAG_formal_parameter) {
1877                         Dwarf_Die tdie;
1878 
1879                         if ((ret = ctf_dwarf_refdie(cup, arg, DW_AT_type,
1880                             &tdie)) != 0)
1881                                 return (ret);
1882 
1883                         if ((ret = ctf_dwarf_convert_type(cup, tdie, &argv[i],
1884                             CTF_ADD_ROOT)) != 0)
1885                                 return (ret);
1886                         i++;
1887 
1888                         /*
1889                          * Once we hit argc entries, we're done. This ensures we
1890                          * don't accidentally hit a varargs which should be the
1891                          * last entry.
1892                          */
1893                         if (i == fip->ctc_argc)
1894                                 break;
1895                 }
1896 
1897                 if ((ret = ctf_dwarf_sib(cup, arg, &sib)) != 0)
1898                         return (ret);
1899                 arg = sib;
1900         }
1901 
1902         return (0);
1903 }
1904 
1905 static int
1906 ctf_dwarf_convert_function(ctf_cu_t *cup, Dwarf_Die die)
1907 {
1908         int ret;
1909         char *name;
1910         ctf_dwfunc_t *cdf;
1911         Dwarf_Die tdie;
1912 
1913         /*
1914          * Functions that don't have a name are generally functions that have
1915          * been inlined and thus most information about them has been lost. If
1916          * we can't get a name, then instead of returning ENOENT, we silently
1917          * swallow the error.
1918          */
1919         if ((ret = ctf_dwarf_string(cup, die, DW_AT_name, &name)) != 0) {
1920                 if (ret == ENOENT)
1921                         return (0);
1922                 return (ret);
1923         }
1924 
1925         ctf_dprintf("beginning work on function %s\n", name);
1926         if ((cdf = ctf_alloc(sizeof (ctf_dwfunc_t))) == NULL) {
1927                 ctf_free(name, strlen(name) + 1);
1928                 return (ENOMEM);
1929         }
1930         bzero(cdf, sizeof (ctf_dwfunc_t));
1931         cdf->cdf_name = name;
1932 
1933         if ((ret = ctf_dwarf_refdie(cup, die, DW_AT_type, &tdie)) == 0) {
1934                 if ((ret = ctf_dwarf_convert_type(cup, tdie,
1935                     &(cdf->cdf_fip.ctc_return), CTF_ADD_ROOT)) != 0) {
1936                         ctf_free(name, strlen(name) + 1);
1937                         ctf_free(cdf, sizeof (ctf_dwfunc_t));
1938                         return (ret);
1939                 }
1940         } else if (ret != ENOENT) {
1941                 ctf_free(name, strlen(name) + 1);
1942                 ctf_free(cdf, sizeof (ctf_dwfunc_t));
1943                 return (ret);
1944         } else {
1945                 if ((cdf->cdf_fip.ctc_return = ctf_dwarf_void(cup)) ==
1946                     CTF_ERR) {
1947                         ctf_free(name, strlen(name) + 1);
1948                         ctf_free(cdf, sizeof (ctf_dwfunc_t));
1949                         return (ctf_errno(cup->cu_ctfp));
1950                 }
1951         }
1952 
1953         /*
1954          * A function has a number of children, some of which may not be ones we
1955          * care about. Children that we care about have a type of
1956          * DW_TAG_formal_parameter. We're going to do two passes, the first to
1957          * count the arguments, the second to process them. Afterwards, we
1958          * should be good to go ahead and add this function.
1959          *
1960          * Note, we already got the return type by going in and grabbing it out
1961          * of the DW_AT_type.
1962          */
1963         if ((ret = ctf_dwarf_function_count(cup, die, &cdf->cdf_fip,
1964             B_FALSE)) != 0) {
1965                 ctf_free(name, strlen(name) + 1);
1966                 ctf_free(cdf, sizeof (ctf_dwfunc_t));
1967                 return (ret);
1968         }
1969 
1970         ctf_dprintf("beginning to convert function arguments %s\n", name);
1971         if (cdf->cdf_fip.ctc_argc != 0) {
1972                 uint_t argc = cdf->cdf_fip.ctc_argc;
1973                 cdf->cdf_argv = ctf_alloc(sizeof (ctf_id_t) * argc);
1974                 if (cdf->cdf_argv == NULL) {
1975                         ctf_free(name, strlen(name) + 1);
1976                         ctf_free(cdf, sizeof (ctf_dwfunc_t));
1977                         return (ENOMEM);
1978                 }
1979                 if ((ret = ctf_dwarf_convert_fargs(cup, die,
1980                     &cdf->cdf_fip, cdf->cdf_argv)) != 0) {
1981                         ctf_free(cdf->cdf_argv, sizeof (ctf_id_t) * argc);
1982                         ctf_free(name, strlen(name) + 1);
1983                         ctf_free(cdf, sizeof (ctf_dwfunc_t));
1984                         return (ret);
1985                 }
1986         } else {
1987                 cdf->cdf_argv = NULL;
1988         }
1989 
1990         if ((ret = ctf_dwarf_isglobal(cup, die, &cdf->cdf_global)) != 0) {
1991                 ctf_free(cdf->cdf_argv, sizeof (ctf_id_t) *
1992                     cdf->cdf_fip.ctc_argc);
1993                 ctf_free(name, strlen(name) + 1);
1994                 ctf_free(cdf, sizeof (ctf_dwfunc_t));
1995                 return (ret);
1996         }
1997 
1998         ctf_list_append(&cup->cu_funcs, cdf);
1999         return (ret);
2000 }
2001 
2002 /*
2003  * Convert variables, but only if they're not prototypes and have names.
2004  */
2005 static int
2006 ctf_dwarf_convert_variable(ctf_cu_t *cup, Dwarf_Die die)
2007 {
2008         int ret;
2009         char *name;
2010         Dwarf_Bool b;
2011         Dwarf_Die tdie;
2012         ctf_id_t id;
2013         ctf_dwvar_t *cdv;
2014 
2015         /* Skip "Non-Defining Declarations" */
2016         if ((ret = ctf_dwarf_boolean(cup, die, DW_AT_declaration, &b)) == 0) {
2017                 if (b != 0)
2018                         return (0);
2019         } else if (ret != ENOENT) {
2020                 return (ret);
2021         }
2022 
2023         /*
2024          * If we find a DIE of "Declarations Completing Non-Defining
2025          * Declarations", we will use the referenced type's DIE.  This isn't
2026          * quite correct, e.g. DW_AT_decl_line will be the forward declaration
2027          * not this site.  It's sufficient for what we need, however: in
2028          * particular, we should find DW_AT_external as needed there.
2029          */
2030         if ((ret = ctf_dwarf_refdie(cup, die, DW_AT_specification,
2031             &tdie)) == 0) {
2032                 Dwarf_Off offset;
2033                 if ((ret = ctf_dwarf_offset(cup, tdie, &offset)) != 0)
2034                         return (ret);
2035                 ctf_dprintf("die 0x%llx DW_AT_specification -> die 0x%llx\n",
2036                     ctf_die_offset(die), ctf_die_offset(tdie));
2037                 die = tdie;
2038         } else if (ret != ENOENT) {
2039                 return (ret);
2040         }
2041 
2042         if ((ret = ctf_dwarf_string(cup, die, DW_AT_name, &name)) != 0 &&
2043             ret != ENOENT)
2044                 return (ret);
2045         if (ret == ENOENT)
2046                 return (0);
2047 
2048         if ((ret = ctf_dwarf_refdie(cup, die, DW_AT_type, &tdie)) != 0) {
2049                 ctf_free(name, strlen(name) + 1);
2050                 return (ret);
2051         }
2052 
2053         if ((ret = ctf_dwarf_convert_type(cup, tdie, &id,
2054             CTF_ADD_ROOT)) != 0)
2055                 return (ret);
2056 
2057         if ((cdv = ctf_alloc(sizeof (ctf_dwvar_t))) == NULL) {
2058                 ctf_free(name, strlen(name) + 1);
2059                 return (ENOMEM);
2060         }
2061 
2062         cdv->cdv_name = name;
2063         cdv->cdv_type = id;
2064 
2065         if ((ret = ctf_dwarf_isglobal(cup, die, &cdv->cdv_global)) != 0) {
2066                 ctf_free(cdv, sizeof (ctf_dwvar_t));
2067                 ctf_free(name, strlen(name) + 1);
2068                 return (ret);
2069         }
2070 
2071         ctf_list_append(&cup->cu_vars, cdv);
2072         return (0);
2073 }
2074 
2075 /*
2076  * Walk through our set of top-level types and process them.
2077  */
2078 static int
2079 ctf_dwarf_walk_toplevel(ctf_cu_t *cup, Dwarf_Die die)
2080 {
2081         int ret;
2082         Dwarf_Off offset;
2083         Dwarf_Half tag;
2084 
2085         if ((ret = ctf_dwarf_offset(cup, die, &offset)) != 0)
2086                 return (ret);
2087 
2088         if (offset > cup->cu_maxoff) {
2089                 (void) snprintf(cup->cu_errbuf, cup->cu_errlen,
2090                     "die offset %llu beyond maximum for header %llu\n",
2091                     offset, cup->cu_maxoff);
2092                 return (ECTF_CONVBKERR);
2093         }
2094 
2095         if ((ret = ctf_dwarf_tag(cup, die, &tag)) != 0)
2096                 return (ret);
2097 
2098         ret = 0;
2099         switch (tag) {
2100         case DW_TAG_subprogram:
2101                 ctf_dprintf("top level func\n");
2102                 ret = ctf_dwarf_convert_function(cup, die);
2103                 break;
2104         case DW_TAG_variable:
2105                 ctf_dprintf("top level var\n");
2106                 ret = ctf_dwarf_convert_variable(cup, die);
2107                 break;
2108         case DW_TAG_lexical_block:
2109                 ctf_dprintf("top level block\n");
2110                 ret = ctf_dwarf_walk_lexical(cup, die);
2111                 break;
2112         case DW_TAG_enumeration_type:
2113         case DW_TAG_structure_type:
2114         case DW_TAG_typedef:
2115         case DW_TAG_union_type:
2116                 ctf_dprintf("top level type\n");
2117                 ret = ctf_dwarf_convert_type(cup, die, NULL, B_TRUE);
2118                 break;
2119         default:
2120                 break;
2121         }
2122 
2123         return (ret);
2124 }
2125 
2126 
2127 /*
2128  * We're given a node. At this node we need to convert it and then proceed to
2129  * convert any siblings that are associaed with this die.
2130  */
2131 static int
2132 ctf_dwarf_convert_die(ctf_cu_t *cup, Dwarf_Die die)
2133 {
2134         while (die != NULL) {
2135                 int ret;
2136                 Dwarf_Die sib;
2137 
2138                 if ((ret = ctf_dwarf_walk_toplevel(cup, die)) != 0)
2139                         return (ret);
2140 
2141                 if ((ret = ctf_dwarf_sib(cup, die, &sib)) != 0)
2142                         return (ret);
2143                 die = sib;
2144         }
2145         return (0);
2146 }
2147 
2148 static int
2149 ctf_dwarf_fixup_die(ctf_cu_t *cup, boolean_t addpass)
2150 {
2151         ctf_dwmap_t *map;
2152 
2153         for (map = avl_first(&cup->cu_map); map != NULL;
2154             map = AVL_NEXT(&cup->cu_map, map)) {
2155                 int ret;
2156                 if (map->cdm_fix == B_FALSE)
2157                         continue;
2158                 if ((ret = ctf_dwarf_fixup_sou(cup, map->cdm_die, map->cdm_id,
2159                     addpass)) != 0)
2160                         return (ret);
2161         }
2162 
2163         return (0);
2164 }
2165 
2166 /*
2167  * The DWARF information about a symbol and the information in the symbol table
2168  * may not be the same due to symbol reduction that is performed by ld due to a
2169  * mapfile or other such directive. We process weak symbols at a later time.
2170  *
2171  * The following are the rules that we employ:
2172  *
2173  * 1. A DWARF function that is considered exported matches STB_GLOBAL entries
2174  * with the same name.
2175  *
2176  * 2. A DWARF function that is considered exported matches STB_LOCAL entries
2177  * with the same name and the same file. This case may happen due to mapfile
2178  * reduction.
2179  *
2180  * 3. A DWARF function that is not considered exported matches STB_LOCAL entries
2181  * with the same name and the same file.
2182  *
2183  * 4. A DWARF function that has the same name as the symbol table entry, but the
2184  * files do not match. This is considered a 'fuzzy' match. This may also happen
2185  * due to a mapfile reduction. Fuzzy matching is only used when we know that the
2186  * file in question refers to the primary object. This is because when a symbol
2187  * is reduced in a mapfile, it's always going to be tagged as a local value in
2188  * the generated output and it is considered as to belong to the primary file
2189  * which is the first STT_FILE symbol we see.
2190  */
2191 static boolean_t
2192 ctf_dwarf_symbol_match(const char *symtab_file, const char *symtab_name,
2193     uint_t symtab_bind, const char *dwarf_file, const char *dwarf_name,
2194     boolean_t dwarf_global, boolean_t *is_fuzzy)
2195 {
2196         *is_fuzzy = B_FALSE;
2197 
2198         if (symtab_bind != STB_LOCAL && symtab_bind != STB_GLOBAL) {
2199                 return (B_FALSE);
2200         }
2201 
2202         if (strcmp(symtab_name, dwarf_name) != 0) {
2203                 return (B_FALSE);
2204         }
2205 
2206         if (symtab_bind == STB_GLOBAL) {
2207                 return (dwarf_global);
2208         }
2209 
2210         if (strcmp(symtab_file, dwarf_file) == 0) {
2211                 return (B_TRUE);
2212         }
2213 
2214         if (dwarf_global) {
2215                 *is_fuzzy = B_TRUE;
2216                 return (B_TRUE);
2217         }
2218 
2219         return (B_FALSE);
2220 }
2221 
2222 static ctf_dwfunc_t *
2223 ctf_dwarf_match_func(ctf_cu_t *cup, const char *file, const char *name,
2224     uint_t bind, boolean_t primary)
2225 {
2226         ctf_dwfunc_t *cdf, *fuzzy = NULL;
2227 
2228         if (bind == STB_WEAK)
2229                 return (NULL);
2230 
2231         if (bind == STB_LOCAL && (file == NULL || cup->cu_name == NULL))
2232                 return (NULL);
2233 
2234         for (cdf = ctf_list_next(&cup->cu_funcs); cdf != NULL;
2235             cdf = ctf_list_next(cdf)) {
2236                 boolean_t is_fuzzy = B_FALSE;
2237 
2238                 if (ctf_dwarf_symbol_match(file, name, bind, cup->cu_name,
2239                     cdf->cdf_name, cdf->cdf_global, &is_fuzzy)) {
2240                         if (is_fuzzy) {
2241                                 if (primary) {
2242                                         fuzzy = cdf;
2243                                 }
2244                                 continue;
2245                         } else {
2246                                 return (cdf);
2247                         }
2248                 }
2249         }
2250 
2251         return (fuzzy);
2252 }
2253 
2254 static ctf_dwvar_t *
2255 ctf_dwarf_match_var(ctf_cu_t *cup, const char *file, const char *name,
2256     uint_t bind, boolean_t primary)
2257 {
2258         ctf_dwvar_t *cdv, *fuzzy = NULL;
2259 
2260         if (bind == STB_WEAK)
2261                 return (NULL);
2262 
2263         if (bind == STB_LOCAL && (file == NULL || cup->cu_name == NULL))
2264                 return (NULL);
2265 
2266         for (cdv = ctf_list_next(&cup->cu_vars); cdv != NULL;
2267             cdv = ctf_list_next(cdv)) {
2268                 boolean_t is_fuzzy = B_FALSE;
2269 
2270                 if (ctf_dwarf_symbol_match(file, name, bind, cup->cu_name,
2271                     cdv->cdv_name, cdv->cdv_global, &is_fuzzy)) {
2272                         if (is_fuzzy) {
2273                                 if (primary) {
2274                                         fuzzy = cdv;
2275                                 }
2276                         } else {
2277                                 return (cdv);
2278                         }
2279                 }
2280         }
2281 
2282         return (fuzzy);
2283 }
2284 
2285 static int
2286 ctf_dwarf_conv_funcvars_cb(const Elf64_Sym *symp, ulong_t idx,
2287     const char *file, const char *name, boolean_t primary, void *arg)
2288 {
2289         int ret;
2290         uint_t bind, type;
2291         ctf_cu_t *cup = arg;
2292 
2293         bind = GELF_ST_BIND(symp->st_info);
2294         type = GELF_ST_TYPE(symp->st_info);
2295 
2296         /*
2297          * Come back to weak symbols in another pass
2298          */
2299         if (bind == STB_WEAK)
2300                 return (0);
2301 
2302         if (type == STT_OBJECT) {
2303                 ctf_dwvar_t *cdv = ctf_dwarf_match_var(cup, file, name,
2304                     bind, primary);
2305                 if (cdv == NULL)
2306                         return (0);
2307                 ret = ctf_add_object(cup->cu_ctfp, idx, cdv->cdv_type);
2308                 ctf_dprintf("added object %s->%ld\n", name, cdv->cdv_type);
2309         } else {
2310                 ctf_dwfunc_t *cdf = ctf_dwarf_match_func(cup, file, name,
2311                     bind, primary);
2312                 if (cdf == NULL)
2313                         return (0);
2314                 ret = ctf_add_function(cup->cu_ctfp, idx, &cdf->cdf_fip,
2315                     cdf->cdf_argv);
2316                 ctf_dprintf("added function %s\n", name);
2317         }
2318 
2319         if (ret == CTF_ERR) {
2320                 return (ctf_errno(cup->cu_ctfp));
2321         }
2322 
2323         return (0);
2324 }
2325 
2326 static int
2327 ctf_dwarf_conv_funcvars(ctf_cu_t *cup)
2328 {
2329         return (ctf_symtab_iter(cup->cu_ctfp, ctf_dwarf_conv_funcvars_cb, cup));
2330 }
2331 
2332 /*
2333  * If we have a weak symbol, attempt to find the strong symbol it will resolve
2334  * to.  Note: the code where this actually happens is in sym_process() in
2335  * cmd/sgs/libld/common/syms.c
2336  *
2337  * Finding the matching symbol is unfortunately not trivial.  For a symbol to be
2338  * a candidate, it must:
2339  *
2340  * - have the same type (function, object)
2341  * - have the same value (address)
2342  * - have the same size
2343  * - not be another weak symbol
2344  * - belong to the same section (checked via section index)
2345  *
2346  * To perform this check, we first iterate over the symbol table. For each weak
2347  * symbol that we encounter, we then do a second walk over the symbol table,
2348  * calling ctf_dwarf_conv_check_weak(). If a symbol matches the above, then it's
2349  * either a local or global symbol. If we find a global symbol then we go with
2350  * it and stop searching for additional matches.
2351  *
2352  * If instead, we find a local symbol, things are more complicated. The first
2353  * thing we do is to try and see if we have file information about both symbols
2354  * (STT_FILE). If they both have file information and it matches, then we treat
2355  * that as a good match and stop searching for additional matches.
2356  *
2357  * Otherwise, this means we have a non-matching file and a local symbol. We
2358  * treat this as a candidate and if we find a better match (one of the two cases
2359  * above), use that instead. There are two different ways this can happen.
2360  * Either this is a completely different symbol, or it's a once-global symbol
2361  * that was scoped to local via a mapfile.  In the former case, curfile is
2362  * likely inaccurate since the linker does not preserve the needed curfile in
2363  * the order of the symbol table (see the comments about locally scoped symbols
2364  * in libld's update_osym()).  As we can't tell this case from the former one,
2365  * we use this symbol iff no other matching symbol is found.
2366  *
2367  * What we really need here is a SUNW section containing weak<->strong mappings
2368  * that we can consume.
2369  */
2370 typedef struct ctf_dwarf_weak_arg {
2371         const Elf64_Sym *cweak_symp;
2372         const char *cweak_file;
2373         boolean_t cweak_candidate;
2374         ulong_t cweak_idx;
2375 } ctf_dwarf_weak_arg_t;
2376 
2377 static int
2378 ctf_dwarf_conv_check_weak(const Elf64_Sym *symp, ulong_t idx, const char *file,
2379     const char *name, boolean_t primary, void *arg)
2380 {
2381         ctf_dwarf_weak_arg_t *cweak = arg;
2382 
2383         const Elf64_Sym *wsymp = cweak->cweak_symp;
2384 
2385         ctf_dprintf("comparing weak to %s\n", name);
2386 
2387         if (GELF_ST_BIND(symp->st_info) == STB_WEAK) {
2388                 return (0);
2389         }
2390 
2391         if (GELF_ST_TYPE(wsymp->st_info) != GELF_ST_TYPE(symp->st_info)) {
2392                 return (0);
2393         }
2394 
2395         if (wsymp->st_value != symp->st_value) {
2396                 return (0);
2397         }
2398 
2399         if (wsymp->st_size != symp->st_size) {
2400                 return (0);
2401         }
2402 
2403         if (wsymp->st_shndx != symp->st_shndx) {
2404                 return (0);
2405         }
2406 
2407         /*
2408          * Check if it's a weak candidate.
2409          */
2410         if (GELF_ST_BIND(symp->st_info) == STB_LOCAL &&
2411             (file == NULL || cweak->cweak_file == NULL ||
2412             strcmp(file, cweak->cweak_file) != 0)) {
2413                 cweak->cweak_candidate = B_TRUE;
2414                 cweak->cweak_idx = idx;
2415                 return (0);
2416         }
2417 
2418         /*
2419          * Found a match, break.
2420          */
2421         cweak->cweak_idx = idx;
2422         return (1);
2423 }
2424 
2425 static int
2426 ctf_dwarf_duplicate_sym(ctf_cu_t *cup, ulong_t idx, ulong_t matchidx)
2427 {
2428         ctf_id_t id = ctf_lookup_by_symbol(cup->cu_ctfp, matchidx);
2429 
2430         /*
2431          * If we matched something that for some reason didn't have type data,
2432          * we don't consider that a fatal error and silently swallow it.
2433          */
2434         if (id == CTF_ERR) {
2435                 if (ctf_errno(cup->cu_ctfp) == ECTF_NOTYPEDAT)
2436                         return (0);
2437                 else
2438                         return (ctf_errno(cup->cu_ctfp));
2439         }
2440 
2441         if (ctf_add_object(cup->cu_ctfp, idx, id) == CTF_ERR)
2442                 return (ctf_errno(cup->cu_ctfp));
2443 
2444         return (0);
2445 }
2446 
2447 static int
2448 ctf_dwarf_duplicate_func(ctf_cu_t *cup, ulong_t idx, ulong_t matchidx)
2449 {
2450         int ret;
2451         ctf_funcinfo_t fip;
2452         ctf_id_t *args = NULL;
2453 
2454         if (ctf_func_info(cup->cu_ctfp, matchidx, &fip) == CTF_ERR) {
2455                 if (ctf_errno(cup->cu_ctfp) == ECTF_NOFUNCDAT)
2456                         return (0);
2457                 else
2458                         return (ctf_errno(cup->cu_ctfp));
2459         }
2460 
2461         if (fip.ctc_argc != 0) {
2462                 args = ctf_alloc(sizeof (ctf_id_t) * fip.ctc_argc);
2463                 if (args == NULL)
2464                         return (ENOMEM);
2465 
2466                 if (ctf_func_args(cup->cu_ctfp, matchidx, fip.ctc_argc, args) ==
2467                     CTF_ERR) {
2468                         ctf_free(args, sizeof (ctf_id_t) * fip.ctc_argc);
2469                         return (ctf_errno(cup->cu_ctfp));
2470                 }
2471         }
2472 
2473         ret = ctf_add_function(cup->cu_ctfp, idx, &fip, args);
2474         if (args != NULL)
2475                 ctf_free(args, sizeof (ctf_id_t) * fip.ctc_argc);
2476         if (ret == CTF_ERR)
2477                 return (ctf_errno(cup->cu_ctfp));
2478 
2479         return (0);
2480 }
2481 
2482 static int
2483 ctf_dwarf_conv_weaks_cb(const Elf64_Sym *symp, ulong_t idx, const char *file,
2484     const char *name, boolean_t primary, void *arg)
2485 {
2486         int ret, type;
2487         ctf_dwarf_weak_arg_t cweak;
2488         ctf_cu_t *cup = arg;
2489 
2490         /*
2491          * We only care about weak symbols.
2492          */
2493         if (GELF_ST_BIND(symp->st_info) != STB_WEAK)
2494                 return (0);
2495 
2496         type = GELF_ST_TYPE(symp->st_info);
2497         ASSERT(type == STT_OBJECT || type == STT_FUNC);
2498 
2499         /*
2500          * For each weak symbol we encounter, we need to do a second iteration
2501          * to try and find a match. We should probably think about other
2502          * techniques to try and save us time in the future.
2503          */
2504         cweak.cweak_symp = symp;
2505         cweak.cweak_file = file;
2506         cweak.cweak_candidate = B_FALSE;
2507         cweak.cweak_idx = 0;
2508 
2509         ctf_dprintf("Trying to find weak equiv for %s\n", name);
2510 
2511         ret = ctf_symtab_iter(cup->cu_ctfp, ctf_dwarf_conv_check_weak, &cweak);
2512         VERIFY(ret == 0 || ret == 1);
2513 
2514         /*
2515          * Nothing was ever found, we're not going to add anything for this
2516          * entry.
2517          */
2518         if (ret == 0 && cweak.cweak_candidate == B_FALSE) {
2519                 ctf_dprintf("found no weak match for %s\n", name);
2520                 return (0);
2521         }
2522 
2523         /*
2524          * Now, finally go and add the type based on the match.
2525          */
2526         ctf_dprintf("matched weak symbol %lu to %lu\n", idx, cweak.cweak_idx);
2527         if (type == STT_OBJECT) {
2528                 ret = ctf_dwarf_duplicate_sym(cup, idx, cweak.cweak_idx);
2529         } else {
2530                 ret = ctf_dwarf_duplicate_func(cup, idx, cweak.cweak_idx);
2531         }
2532 
2533         return (ret);
2534 }
2535 
2536 static int
2537 ctf_dwarf_conv_weaks(ctf_cu_t *cup)
2538 {
2539         return (ctf_symtab_iter(cup->cu_ctfp, ctf_dwarf_conv_weaks_cb, cup));
2540 }
2541 
2542 /* ARGSUSED */
2543 static int
2544 ctf_dwarf_convert_one(void *arg, void *unused)
2545 {
2546         int ret;
2547         ctf_file_t *dedup;
2548         ctf_cu_t *cup = arg;
2549 
2550         ctf_dprintf("converting die: %s\n", cup->cu_name);
2551         ctf_dprintf("max offset: %x\n", cup->cu_maxoff);
2552         VERIFY(cup != NULL);
2553 
2554         ret = ctf_dwarf_convert_die(cup, cup->cu_cu);
2555         ctf_dprintf("ctf_dwarf_convert_die (%s) returned %d\n", cup->cu_name,
2556             ret);
2557         if (ret != 0) {
2558                 return (ret);
2559         }
2560         if (ctf_update(cup->cu_ctfp) != 0) {
2561                 return (ctf_dwarf_error(cup, cup->cu_ctfp, 0,
2562                     "failed to update output ctf container"));
2563         }
2564 
2565         ret = ctf_dwarf_fixup_die(cup, B_FALSE);
2566         ctf_dprintf("ctf_dwarf_fixup_die (%s) returned %d\n", cup->cu_name,
2567             ret);
2568         if (ret != 0) {
2569                 return (ret);
2570         }
2571         if (ctf_update(cup->cu_ctfp) != 0) {
2572                 return (ctf_dwarf_error(cup, cup->cu_ctfp, 0,
2573                     "failed to update output ctf container"));
2574         }
2575 
2576         ret = ctf_dwarf_fixup_die(cup, B_TRUE);
2577         ctf_dprintf("ctf_dwarf_fixup_die (%s) returned %d\n", cup->cu_name,
2578             ret);
2579         if (ret != 0) {
2580                 return (ret);
2581         }
2582         if (ctf_update(cup->cu_ctfp) != 0) {
2583                 return (ctf_dwarf_error(cup, cup->cu_ctfp, 0,
2584                     "failed to update output ctf container"));
2585         }
2586 
2587 
2588         if ((ret = ctf_dwarf_conv_funcvars(cup)) != 0) {
2589                 return (ctf_dwarf_error(cup, NULL, ret,
2590                     "failed to convert strong functions and variables"));
2591         }
2592 
2593         if (ctf_update(cup->cu_ctfp) != 0) {
2594                 return (ctf_dwarf_error(cup, cup->cu_ctfp, 0,
2595                     "failed to update output ctf container"));
2596         }
2597 
2598         if (cup->cu_doweaks == B_TRUE) {
2599                 if ((ret = ctf_dwarf_conv_weaks(cup)) != 0) {
2600                         return (ctf_dwarf_error(cup, NULL, ret,
2601                             "failed to convert weak functions and variables"));
2602                 }
2603 
2604                 if (ctf_update(cup->cu_ctfp) != 0) {
2605                         return (ctf_dwarf_error(cup, cup->cu_ctfp, 0,
2606                             "failed to update output ctf container"));
2607                 }
2608         }
2609 
2610         ctf_phase_dump(cup->cu_ctfp, "pre-dwarf-dedup", cup->cu_name);
2611         ctf_dprintf("adding inputs for dedup\n");
2612         if ((ret = ctf_merge_add(cup->cu_cmh, cup->cu_ctfp)) != 0) {
2613                 return (ctf_dwarf_error(cup, NULL, ret,
2614                     "failed to add inputs for merge"));
2615         }
2616 
2617         ctf_dprintf("starting dedup of %s\n", cup->cu_name);
2618         if ((ret = ctf_merge_dedup(cup->cu_cmh, &dedup)) != 0) {
2619                 return (ctf_dwarf_error(cup, NULL, ret,
2620                     "failed to deduplicate die"));
2621         }
2622         ctf_close(cup->cu_ctfp);
2623         cup->cu_ctfp = dedup;
2624         ctf_phase_dump(cup->cu_ctfp, "post-dwarf-dedup", cup->cu_name);
2625 
2626         return (0);
2627 }
2628 
2629 /*
2630  * Note, we expect that if we're returning a ctf_file_t from one of the dies,
2631  * say in the single node case, it's been saved and the entry here has been set
2632  * to NULL, which ctf_close happily ignores.
2633  */
2634 static void
2635 ctf_dwarf_free_die(ctf_cu_t *cup)
2636 {
2637         ctf_dwfunc_t *cdf, *ndf;
2638         ctf_dwvar_t *cdv, *ndv;
2639         ctf_dwbitf_t *cdb, *ndb;
2640         ctf_dwmap_t *map;
2641         void *cookie;
2642         Dwarf_Error derr;
2643 
2644         ctf_dprintf("Beginning to free die: %p\n", cup);
2645         cup->cu_elf = NULL;
2646         ctf_dprintf("Trying to free name: %p\n", cup->cu_name);
2647         if (cup->cu_name != NULL)
2648                 ctf_free(cup->cu_name, strlen(cup->cu_name) + 1);
2649         ctf_dprintf("Trying to free merge handle: %p\n", cup->cu_cmh);
2650         if (cup->cu_cmh != NULL) {
2651                 ctf_merge_fini(cup->cu_cmh);
2652                 cup->cu_cmh = NULL;
2653         }
2654 
2655         ctf_dprintf("Trying to free functions\n");
2656         for (cdf = ctf_list_next(&cup->cu_funcs); cdf != NULL; cdf = ndf) {
2657                 ndf = ctf_list_next(cdf);
2658                 ctf_free(cdf->cdf_name, strlen(cdf->cdf_name) + 1);
2659                 if (cdf->cdf_fip.ctc_argc != 0) {
2660                         ctf_free(cdf->cdf_argv,
2661                             sizeof (ctf_id_t) * cdf->cdf_fip.ctc_argc);
2662                 }
2663                 ctf_free(cdf, sizeof (ctf_dwfunc_t));
2664         }
2665 
2666         ctf_dprintf("Trying to free variables\n");
2667         for (cdv = ctf_list_next(&cup->cu_vars); cdv != NULL; cdv = ndv) {
2668                 ndv = ctf_list_next(cdv);
2669                 ctf_free(cdv->cdv_name, strlen(cdv->cdv_name) + 1);
2670                 ctf_free(cdv, sizeof (ctf_dwvar_t));
2671         }
2672 
2673         ctf_dprintf("Trying to free bitfields\n");
2674         for (cdb = ctf_list_next(&cup->cu_bitfields); cdb != NULL; cdb = ndb) {
2675                 ndb = ctf_list_next(cdb);
2676                 ctf_free(cdb, sizeof (ctf_dwbitf_t));
2677         }
2678 
2679         ctf_dprintf("Trying to clean up dwarf_t: %p\n", cup->cu_dwarf);
2680         (void) dwarf_finish(cup->cu_dwarf, &derr);
2681         cup->cu_dwarf = NULL;
2682         ctf_close(cup->cu_ctfp);
2683 
2684         cookie = NULL;
2685         while ((map = avl_destroy_nodes(&cup->cu_map, &cookie)) != NULL) {
2686                 ctf_free(map, sizeof (ctf_dwmap_t));
2687         }
2688         avl_destroy(&cup->cu_map);
2689         cup->cu_errbuf = NULL;
2690 }
2691 
2692 static void
2693 ctf_dwarf_free_dies(ctf_cu_t *cdies, int ndies)
2694 {
2695         int i;
2696 
2697         ctf_dprintf("Beginning to free dies\n");
2698         for (i = 0; i < ndies; i++) {
2699                 ctf_dwarf_free_die(&cdies[i]);
2700         }
2701 
2702         ctf_free(cdies, sizeof (ctf_cu_t) * ndies);
2703 }
2704 
2705 static int
2706 ctf_dwarf_count_dies(Dwarf_Debug dw, Dwarf_Error *derr, int *ndies,
2707     char *errbuf, size_t errlen)
2708 {
2709         int ret;
2710         Dwarf_Half vers;
2711         Dwarf_Unsigned nexthdr;
2712 
2713         while ((ret = dwarf_next_cu_header(dw, NULL, &vers, NULL, NULL,
2714             &nexthdr, derr)) != DW_DLV_NO_ENTRY) {
2715                 if (ret != DW_DLV_OK) {
2716                         (void) snprintf(errbuf, errlen,
2717                             "file does not contain valid DWARF data: %s\n",
2718                             dwarf_errmsg(*derr));
2719                         return (ECTF_CONVBKERR);
2720                 }
2721 
2722                 if (vers != DWARF_VERSION_TWO) {
2723                         (void) snprintf(errbuf, errlen,
2724                             "unsupported DWARF version: %d\n", vers);
2725                         return (ECTF_CONVBKERR);
2726                 }
2727                 *ndies = *ndies + 1;
2728         }
2729 
2730         if (*ndies == 0) {
2731                 (void) snprintf(errbuf, errlen,
2732                     "file does not contain valid DWARF data: %s\n",
2733                     dwarf_errmsg(*derr));
2734                 return (ECTF_CONVBKERR);
2735         }
2736 
2737         return (0);
2738 }
2739 
2740 static int
2741 ctf_dwarf_init_die(int fd, Elf *elf, ctf_cu_t *cup, int ndie, char *errbuf,
2742     size_t errlen)
2743 {
2744         int ret;
2745         Dwarf_Unsigned hdrlen, abboff, nexthdr;
2746         Dwarf_Half addrsz;
2747         Dwarf_Unsigned offset = 0;
2748         Dwarf_Error derr;
2749 
2750         while ((ret = dwarf_next_cu_header(cup->cu_dwarf, &hdrlen, NULL,
2751             &abboff, &addrsz, &nexthdr, &derr)) != DW_DLV_NO_ENTRY) {
2752                 char *name;
2753                 Dwarf_Die cu, child;
2754 
2755                 /* Based on the counting above, we should be good to go */
2756                 VERIFY(ret == DW_DLV_OK);
2757                 if (ndie > 0) {
2758                         ndie--;
2759                         offset = nexthdr;
2760                         continue;
2761                 }
2762 
2763                 /*
2764                  * Compilers are apparently inconsistent. Some emit no DWARF for
2765                  * empty files and others emit empty compilation unit.
2766                  */
2767                 cup->cu_voidtid = CTF_ERR;
2768                 cup->cu_longtid = CTF_ERR;
2769                 cup->cu_elf = elf;
2770                 cup->cu_maxoff = nexthdr - 1;
2771                 cup->cu_ctfp = ctf_fdcreate(fd, &ret);
2772                 if (cup->cu_ctfp == NULL) {
2773                         ctf_free(cup, sizeof (ctf_cu_t));
2774                         return (ret);
2775                 }
2776                 avl_create(&cup->cu_map, ctf_dwmap_comp, sizeof (ctf_dwmap_t),
2777                     offsetof(ctf_dwmap_t, cdm_avl));
2778                 cup->cu_errbuf = errbuf;
2779                 cup->cu_errlen = errlen;
2780                 bzero(&cup->cu_vars, sizeof (ctf_list_t));
2781                 bzero(&cup->cu_funcs, sizeof (ctf_list_t));
2782                 bzero(&cup->cu_bitfields, sizeof (ctf_list_t));
2783 
2784                 if ((ret = ctf_dwarf_die_elfenc(elf, cup, errbuf,
2785                     errlen)) != 0) {
2786                         avl_destroy(&cup->cu_map);
2787                         ctf_free(cup, sizeof (ctf_cu_t));
2788                         return (ret);
2789                 }
2790 
2791                 if ((ret = ctf_dwarf_sib(cup, NULL, &cu)) != 0) {
2792                         avl_destroy(&cup->cu_map);
2793                         ctf_free(cup, sizeof (ctf_cu_t));
2794                         return (ret);
2795                 }
2796                 if (cu == NULL) {
2797                         (void) snprintf(errbuf, errlen,
2798                             "file does not contain DWARF data\n");
2799                         avl_destroy(&cup->cu_map);
2800                         ctf_free(cup, sizeof (ctf_cu_t));
2801                         return (ECTF_CONVBKERR);
2802                 }
2803 
2804                 if ((ret = ctf_dwarf_child(cup, cu, &child)) != 0) {
2805                         avl_destroy(&cup->cu_map);
2806                         ctf_free(cup, sizeof (ctf_cu_t));
2807                         return (ret);
2808                 }
2809                 if (child == NULL) {
2810                         (void) snprintf(errbuf, errlen,
2811                             "file does not contain DWARF data\n");
2812                         avl_destroy(&cup->cu_map);
2813                         ctf_free(cup, sizeof (ctf_cu_t));
2814                         return (ECTF_CONVBKERR);
2815                 }
2816 
2817                 cup->cu_cuoff = offset;
2818                 cup->cu_cu = child;
2819 
2820                 if ((cup->cu_cmh = ctf_merge_init(fd, &ret)) == NULL) {
2821                         avl_destroy(&cup->cu_map);
2822                         ctf_free(cup, sizeof (ctf_cu_t));
2823                         return (ret);
2824                 }
2825 
2826                 if (ctf_dwarf_string(cup, cu, DW_AT_name, &name) == 0) {
2827                         size_t len = strlen(name) + 1;
2828                         char *b = basename(name);
2829                         cup->cu_name = strdup(b);
2830                         ctf_free(name, len);
2831                 }
2832                 break;
2833         }
2834 
2835         return (0);
2836 }
2837 
2838 
2839 ctf_conv_status_t
2840 ctf_dwarf_convert(int fd, Elf *elf, uint_t nthrs, int *errp, ctf_file_t **fpp,
2841     char *errmsg, size_t errlen)
2842 {
2843         int err, ret, ndies, i;
2844         Dwarf_Debug dw;
2845         Dwarf_Error derr;
2846         ctf_cu_t *cdies = NULL, *cup;
2847         workq_t *wqp = NULL;
2848 
2849         if (errp == NULL)
2850                 errp = &err;
2851         *errp = 0;
2852         *fpp = NULL;
2853 
2854         ret = dwarf_elf_init(elf, DW_DLC_READ, NULL, NULL, &dw, &derr);
2855         if (ret != DW_DLV_OK) {
2856                 /*
2857                  * We may want to expect DWARF data here and fail conversion if
2858                  * it's missing. In this case, if we actually have some amount
2859                  * of DWARF, but no section, for now, just go ahead and create
2860                  * an empty CTF file.
2861                  */
2862                 if (ret == DW_DLV_NO_ENTRY ||
2863                     dwarf_errno(derr) == DW_DLE_DEBUG_INFO_NULL) {
2864                         *fpp = ctf_create(errp);
2865                         return (*fpp != NULL ? CTF_CONV_SUCCESS :
2866                             CTF_CONV_ERROR);
2867                 }
2868                 (void) snprintf(errmsg, errlen,
2869                     "failed to initialize DWARF: %s\n",
2870                     dwarf_errmsg(derr));
2871                 *errp = ECTF_CONVBKERR;
2872                 return (CTF_CONV_ERROR);
2873         }
2874 
2875         /*
2876          * Iterate over all of the compilation units and create a ctf_cu_t for
2877          * each of them.  This is used to determine if we have zero, one, or
2878          * multiple dies to convert. If we have zero, that's an error. If
2879          * there's only one die, that's the simple case.  No merge needed and
2880          * only a single Dwarf_Debug as well.
2881          */
2882         ndies = 0;
2883         ret = ctf_dwarf_count_dies(dw, &derr, &ndies, errmsg, errlen);
2884         if (ret != 0) {
2885                 *errp = ret;
2886                 goto out;
2887         }
2888 
2889         (void) dwarf_finish(dw, &derr);
2890         cdies = ctf_alloc(sizeof (ctf_cu_t) * ndies);
2891         if (cdies == NULL) {
2892                 *errp = ENOMEM;
2893                 return (CTF_CONV_ERROR);
2894         }
2895 
2896         for (i = 0; i < ndies; i++) {
2897                 cup = &cdies[i];
2898                 ret = dwarf_elf_init(elf, DW_DLC_READ, NULL, NULL,
2899                     &cup->cu_dwarf, &derr);
2900                 if (ret != 0) {
2901                         ctf_free(cdies, sizeof (ctf_cu_t) * ndies);
2902                         (void) snprintf(errmsg, errlen,
2903                             "failed to initialize DWARF: %s\n",
2904                             dwarf_errmsg(derr));
2905                         *errp = ECTF_CONVBKERR;
2906                         return (CTF_CONV_ERROR);
2907                 }
2908 
2909                 ret = ctf_dwarf_init_die(fd, elf, &cdies[i], i, errmsg, errlen);
2910                 if (ret != 0) {
2911                         *errp = ret;
2912                         goto out;
2913                 }
2914 
2915                 cup->cu_doweaks = ndies > 1 ? B_FALSE : B_TRUE;
2916         }
2917 
2918         ctf_dprintf("found %d DWARF CUs\n", ndies);
2919 
2920         /*
2921          * If we only have one compilation unit, there's no reason to use
2922          * multiple threads, even if the user requested them. After all, they
2923          * just gave us an upper bound.
2924          */
2925         if (ndies == 1)
2926                 nthrs = 1;
2927 
2928         if (workq_init(&wqp, nthrs) == -1) {
2929                 *errp = errno;
2930                 goto out;
2931         }
2932 
2933         for (i = 0; i < ndies; i++) {
2934                 cup = &cdies[i];
2935                 ctf_dprintf("adding cu %s: %p, %x %x\n", cup->cu_name,
2936                     cup->cu_cu, cup->cu_cuoff, cup->cu_maxoff);
2937                 if (workq_add(wqp, cup) == -1) {
2938                         *errp = errno;
2939                         goto out;
2940                 }
2941         }
2942 
2943         ret = workq_work(wqp, ctf_dwarf_convert_one, NULL, errp);
2944         if (ret == WORKQ_ERROR) {
2945                 *errp = errno;
2946                 goto out;
2947         } else if (ret == WORKQ_UERROR) {
2948                 ctf_dprintf("internal convert failed: %s\n",
2949                     ctf_errmsg(*errp));
2950                 goto out;
2951         }
2952 
2953         ctf_dprintf("Determining next phase: have %d CUs\n", ndies);
2954         if (ndies != 1) {
2955                 ctf_merge_t *cmp;
2956 
2957                 cmp = ctf_merge_init(fd, &ret);
2958                 if (cmp == NULL) {
2959                         *errp = ret;
2960                         goto out;
2961                 }
2962 
2963                 ctf_dprintf("setting threads\n");
2964                 if ((ret = ctf_merge_set_nthreads(cmp, nthrs)) != 0) {
2965                         ctf_merge_fini(cmp);
2966                         *errp = ret;
2967                         goto out;
2968                 }
2969 
2970                 for (i = 0; i < ndies; i++) {
2971                         cup = &cdies[i];
2972                         ctf_dprintf("adding cu %s (%p)\n", cup->cu_name,
2973                             cup->cu_ctfp);
2974                         if ((ret = ctf_merge_add(cmp, cup->cu_ctfp)) != 0) {
2975                                 ctf_merge_fini(cmp);
2976                                 *errp = ret;
2977                                 goto out;
2978                         }
2979                 }
2980 
2981                 ctf_dprintf("performing merge\n");
2982                 ret = ctf_merge_merge(cmp, fpp);
2983                 if (ret != 0) {
2984                         ctf_dprintf("failed merge!\n");
2985                         *fpp = NULL;
2986                         ctf_merge_fini(cmp);
2987                         *errp = ret;
2988                         goto out;
2989                 }
2990                 ctf_merge_fini(cmp);
2991                 *errp = 0;
2992                 ctf_dprintf("successfully converted!\n");
2993         } else {
2994                 *errp = 0;
2995                 *fpp = cdies->cu_ctfp;
2996                 cdies->cu_ctfp = NULL;
2997                 ctf_dprintf("successfully converted!\n");
2998         }
2999 
3000 out:
3001         workq_fini(wqp);
3002         ctf_dwarf_free_dies(cdies, ndies);
3003         return (*fpp != NULL ? CTF_CONV_SUCCESS : CTF_CONV_ERROR);
3004 }