usr/src/tools/ctf/cvt/stabs.c

   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 2006 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 /*
  29  * Routines used to read stabs data from a file, and to build a tdata structure
  30  * based on the interesting parts of that data.
  31  */
  32
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <fcntl.h>
  36 #include <unistd.h>
  37 #include <assert.h>
  38 #include <string.h>
  39 #include <libgen.h>
  40 #include <errno.h>
  41 #include <sys/types.h>
  42 #include <sys/param.h>
  43
  44 #include "ctftools.h"
  45 #include "list.h"
  46 #include "stack.h"
  47 #include "memory.h"
  48 #include "traverse.h"
  49
  50 const char *curhdr;
  51
  52 /*
  53  * The stabs generator will sometimes reference types before they've been
  54  * defined.  If this is the case, a TYPEDEF_UNRES tdesc will be generated.
  55  * Note that this is different from a forward declaration, in which the
  56  * stab is defined, but is defined as something that doesn't exist yet.
  57  * When we have read all of the stabs from the file, we can go back and
  58  * fix up all of the unresolved types.  We should be able to fix all of them.
  59  */
  60 /*ARGSUSED2*/
  61 static int
  62 resolve_tou_node(tdesc_t *node, tdesc_t **nodep, void *private)
  63 {
  64         tdesc_t *new;
  65
  66         debug(3, "Trying to resolve %s (%d)\n", tdesc_name(node), node->t_id);
  67         new = lookup(node->t_id);
  68
  69         if (new == NULL) {
  70                 terminate("Couldn't resolve type %d\n", node->t_id);
  71         }
  72
  73         debug(3, " Resolving to %d\n", new->t_id);
  74
  75         *nodep = new;
  76
  77         return (1);
  78 }
  79
  80 /*ARGSUSED*/
  81 static int
  82 resolve_fwd_node(tdesc_t *node, tdesc_t **nodep, void *private)
  83 {
  84         tdesc_t *new = lookupname(node->t_name);
  85
  86         debug(3, "Trying to unforward %s (%d)\n", tdesc_name(node), node->t_id);
  87
  88         if (!new || (new->t_type != STRUCT && new->t_type != UNION))
  89                 return (0);
  90
  91         debug(3, " Unforwarded to %d\n", new->t_id);
  92
  93         *nodep = new;
  94
  95         return (1);
  96 }
  97
  98 static tdtrav_cb_f resolve_cbs[] = {
  99         NULL,
 100         NULL,                   /* intrinsic */
 101         NULL,                   /* pointer */
 102         NULL,                   /* array */
 103         NULL,                   /* function */
 104         NULL,                   /* struct */
 105         NULL,                   /* union */
 106         NULL,                   /* enum */
 107         resolve_fwd_node,       /* forward */
 108         NULL,                   /* typedef */
 109         resolve_tou_node,       /* typedef unres */
 110         NULL,                   /* volatile */
 111         NULL,                   /* const */
 112         NULL,                   /* restrict */
 113 };
 114
 115 static void
 116 resolve_nodes(tdata_t *td)
 117 {
 118         debug(2, "Resolving unresolved stabs\n");
 119
 120         (void) iitraverse_hash(td->td_iihash, &td->td_curvgen, resolve_cbs,
 121             NULL, NULL, td);
 122 }
 123
 124 static char *
 125 concat(char *s1, char *s2, int s2strip)
 126 {
 127         int savelen = strlen(s2) - s2strip;
 128         int newlen = (s1 ? strlen(s1) : 0) + savelen + 1;
 129         char *out;
 130
 131         out = xrealloc(s1, newlen);
 132         if (s1)
 133                 strncpy(out + strlen(out), s2, savelen);
 134         else
 135                 strncpy(out, s2, savelen);
 136
 137         out[newlen - 1] = '\0';
 138
 139         return (out);
 140 }
 141
 142 /*
 143  * N_FUN stabs come with their arguments in promoted form.  In order to get the
 144  * actual arguments, we need to wait for the N_PSYM stabs that will come towards
 145  * the end of the function.  These routines free the arguments (fnarg_free) we
 146  * got from the N_FUN stab and add (fnarg_add) the ones from the N_PSYM stabs.
 147  */
 148 static void
 149 fnarg_add(iidesc_t *curfun, iidesc_t *arg)
 150 {
 151         curfun->ii_nargs++;
 152
 153         if (curfun->ii_nargs == 1)
 154                 curfun->ii_args = xmalloc(sizeof (tdesc_t *) * FUNCARG_DEF);
 155         else if (curfun->ii_nargs > FUNCARG_DEF) {
 156                 curfun->ii_args = xrealloc(curfun->ii_args,
 157                     sizeof (tdesc_t *) * curfun->ii_nargs);
 158         }
 159
 160         curfun->ii_args[curfun->ii_nargs - 1] = arg->ii_dtype;
 161         arg->ii_dtype = NULL;
 162 }
 163
 164 static void
 165 fnarg_free(iidesc_t *ii)
 166 {
 167         ii->ii_nargs = 0;
 168         free(ii->ii_args);
 169         ii->ii_args = NULL;
 170 }
 171
 172 /*
 173  * Read the stabs from the stab ELF section, and turn them into a tdesc tree,
 174  * assembled under an iidesc list.
 175  */
 176 int
 177 stabs_read(tdata_t *td, Elf *elf, const char *file)
 178 {
 179         Elf_Scn *scn;
 180         Elf_Data *data;
 181         stab_t *stab;
 182         stk_t *file_stack;
 183         iidesc_t *iidescp;
 184         iidesc_t *curfun = NULL;
 185         char curpath[MAXPATHLEN];
 186         char *curfile = NULL;
 187         char *str;
 188         char *fstr = NULL, *ofstr = NULL;
 189         int stabidx, stabstridx;
 190         int nstabs, rc, i;
 191         int scope = 0;
 192
 193         if (!((stabidx = findelfsecidx(elf, file, ".stab.excl")) >= 0 &&
 194             (stabstridx = findelfsecidx(elf, file, ".stab.exclstr")) >= 0) &&
 195             !((stabidx = findelfsecidx(elf, file, ".stab")) >= 0 &&
 196             (stabstridx = findelfsecidx(elf, file, ".stabstr")) >= 0)) {
 197                 errno = ENOENT;
 198                 return (-1);
 199         }
 200
 201         file_stack = stack_new(free);
 202
 203         stack_push(file_stack, (void *)file);
 204         curhdr = file;
 205
 206         debug(3, "Found stabs in %d, strings in %d\n", stabidx, stabstridx);
 207
 208         scn = elf_getscn(elf, stabidx);
 209         data = elf_rawdata(scn, NULL);
 210         nstabs = data->d_size / sizeof (stab_t);
 211
 212         parse_init(td);
 213         for (i = 0; i < nstabs; i++) {
 214                 stab = &((stab_t *)data->d_buf)[i];
 215
 216                 /* We don't want any local definitions */
 217                 if (stab->n_type == N_LBRAC) {
 218                         scope++;
 219                         debug(3, "stab %d: opening scope (%d)\n", i + 1, scope);
 220                         continue;
 221                 } else if (stab->n_type == N_RBRAC) {
 222                         scope--;
 223                         debug(3, "stab %d: closing scope (%d)\n", i + 1, scope);
 224                         continue;
 225                 } else if (stab->n_type == N_EINCL) {
 226                         /*
 227                          * There's a bug in the 5.2 (Taz) compilers that causes
 228                          * them to emit an extra N_EINCL if there's no actual
 229                          * text in the file being compiled.  To work around this
 230                          * bug, we explicitly check to make sure we're not
 231                          * trying to pop a stack that only has the outer scope
 232                          * on it.
 233                          */
 234                         if (stack_level(file_stack) != 1) {
 235                                 str = (char *)stack_pop(file_stack);
 236                                 free(str);
 237                                 curhdr = (char *)stack_peek(file_stack);
 238                         }
 239                 }
 240
 241                 /* We only care about a subset of the stabs */
 242                 if (!(stab->n_type == N_FUN || stab->n_type == N_GSYM ||
 243                     stab->n_type == N_LCSYM || stab->n_type == N_LSYM ||
 244                     stab->n_type == N_PSYM || stab->n_type == N_ROSYM ||
 245                     stab->n_type == N_RSYM ||
 246                     stab->n_type == N_STSYM || stab->n_type == N_BINCL ||
 247                     stab->n_type == N_SO || stab->n_type == N_OPT))
 248                         continue;
 249
 250                 if ((str = elf_strptr(elf, stabstridx,
 251                     (size_t)stab->n_strx)) == NULL) {
 252                         terminate("%s: Can't find string at %u for stab %d\n",
 253                             file, stab->n_strx, i);
 254                 }
 255
 256                 if (stab->n_type == N_BINCL) {
 257                         curhdr = xstrdup(str);
 258                         stack_push(file_stack, (void *)curhdr);
 259                         continue;
 260                 } else if (stab->n_type == N_SO) {
 261                         if (str[strlen(str) - 1] != '/') {
 262                                 strcpy(curpath, str);
 263                                 curfile = basename(curpath);
 264                         }
 265                         continue;
 266                 } else if (stab->n_type == N_OPT) {
 267                         if (strcmp(str, "gcc2_compiled.") == 0) {
 268                                 terminate("%s: GCC-generated stabs are "
 269                                     "unsupported. Use DWARF instead.\n", file);
 270                         }
 271                         continue;
 272                 }
 273
 274                 if (str[strlen(str) - 1] == '\\') {
 275                         int offset = 1;
 276                         /*
 277                          * There's a bug in the compilers that causes them to
 278                          * generate \ for continuations with just -g (this is
 279                          * ok), and \\ for continuations with -g -O (this is
 280                          * broken).  This bug is "fixed" in the 6.2 compilers
 281                          * via the elimination of continuation stabs.
 282                          */
 283                         if (str[strlen(str) - 2] == '\\')
 284                                 offset = 2;
 285                         fstr = concat(fstr, str, offset);
 286                         continue;
 287                 } else
 288                         fstr = concat(fstr, str, 0);
 289
 290                 debug(3, "%4d: .stabs \"%s\", %#x, %d, %hd, %d (from %s)\n", i,
 291                     fstr, stab->n_type, 0, stab->n_desc,
 292                     stab->n_value, curhdr);
 293
 294                 if (debug_level >= 3)
 295                         check_hash();
 296
 297                 /*
 298                  * Sometimes the compiler stutters, and emits the same stab
 299                  * twice.  This is bad for the parser, which will attempt to
 300                  * redefine the type IDs indicated in the stabs.  This is
 301                  * compiler bug 4433511.
 302                  */
 303                 if (ofstr && strcmp(fstr, ofstr) == 0) {
 304                         debug(3, "Stutter stab\n");
 305                         free(fstr);
 306                         fstr = NULL;
 307                         continue;
 308                 }
 309
 310                 if (ofstr)
 311                         free(ofstr);
 312                 ofstr = fstr;
 313
 314                 iidescp = NULL;
 315
 316                 if ((rc = parse_stab(stab, fstr, &iidescp)) < 0) {
 317                         terminate("%s: Couldn't parse stab \"%s\" "
 318                             "(source file %s)\n", file, str, curhdr);
 319                 }
 320
 321                 if (rc == 0)
 322                         goto parse_loop_end;
 323
 324                 /* Make sure the scope tracking is working correctly */
 325                 assert(stab->n_type != N_FUN || (iidescp->ii_type != II_GFUN &&
 326                     iidescp->ii_type != II_SFUN) || scope == 0);
 327
 328                 /*
 329                  * The only things we care about that are in local scope are
 330                  * the N_PSYM stabs.
 331                  */
 332                 if (scope && stab->n_type != N_PSYM) {
 333                         if (iidescp)
 334                                 iidesc_free(iidescp, NULL);
 335                         goto parse_loop_end;
 336                 }
 337
 338                 switch (iidescp->ii_type) {
 339                 case II_SFUN:
 340                         iidescp->ii_owner = xstrdup(curfile);
 341                         /*FALLTHROUGH*/
 342                 case II_GFUN:
 343                         curfun = iidescp;
 344                         fnarg_free(iidescp);
 345                         iidesc_add(td->td_iihash, iidescp);
 346                         break;
 347
 348                 case II_SVAR:
 349                         iidescp->ii_owner = xstrdup(curfile);
 350                         /*FALLTHROUGH*/
 351                 case II_GVAR:
 352                 case II_TYPE:
 353                 case II_SOU:
 354                         iidesc_add(td->td_iihash, iidescp);
 355                         break;
 356
 357                 case II_PSYM:
 358                         fnarg_add(curfun, iidescp);
 359                         iidesc_free(iidescp, NULL);
 360                         break;
 361                 default:
 362                         aborterr("invalid ii_type %d for stab type %d",
 363                             iidescp->ii_type, stab->n_type);
 364                 }
 365
 366 parse_loop_end:
 367                 fstr = NULL;
 368         }
 369
 370         if (ofstr)
 371                 free(ofstr);
 372
 373         resolve_nodes(td);
 374         resolve_typed_bitfields();
 375         parse_finish(td);
 376
 377         cvt_fixstabs(td);
 378         cvt_fixups(td, elf_ptrsz(elf));
 379
 380         return (0);
 381 }