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