1 /* Get macro information.
2 Copyright (C) 2002-2009, 2014 Red Hat, Inc.
3 This file is part of elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2002.
6 This file is free software; you can redistribute it and/or modify
7 it under the terms of either
9 * the GNU Lesser General Public License as published by the Free
10 Software Foundation; either version 3 of the License, or (at
11 your option) any later version
15 * the GNU General Public License as published by the Free
16 Software Foundation; either version 2 of the License, or (at
17 your option) any later version
19 or both in parallel, as here.
21 elfutils is distributed in the hope that it will be useful, but
22 WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 General Public License for more details.
26 You should have received copies of the GNU General Public License and
27 the GNU Lesser General Public License along with this program. If
28 not, see <http://www.gnu.org/licenses/>. */
43 get_offset_from (Dwarf_Die *die, int name, Dwarf_Word *retp)
45 /* Get the appropriate attribute. */
47 if (INTUSE(dwarf_attr) (die, name, &attr) == NULL)
50 /* Offset into the corresponding section. */
51 return INTUSE(dwarf_formudata) (&attr, retp);
55 macro_op_compare (const void *p1, const void *p2)
57 const Dwarf_Macro_Op_Table *t1 = (const Dwarf_Macro_Op_Table *) p1;
58 const Dwarf_Macro_Op_Table *t2 = (const Dwarf_Macro_Op_Table *) p2;
60 if (t1->offset < t2->offset)
62 if (t1->offset > t2->offset)
65 if (t1->sec_index < t2->sec_index)
67 if (t1->sec_index > t2->sec_index)
74 build_table (Dwarf_Macro_Op_Table *table,
75 Dwarf_Macro_Op_Proto op_protos[static 255])
78 for (unsigned i = 1; i < 256; ++i)
79 if (op_protos[i - 1].forms != NULL)
80 table->table[table->opcodes[i - 1] = ct++] = op_protos[i - 1];
82 table->opcodes[i - 1] = 0xff;
85 #define MACRO_PROTO(NAME, ...) \
86 Dwarf_Macro_Op_Proto NAME = ({ \
87 static const uint8_t proto[] = {__VA_ARGS__}; \
88 (Dwarf_Macro_Op_Proto) {sizeof proto, proto}; \
91 enum { macinfo_data_size = offsetof (Dwarf_Macro_Op_Table, table[5]) };
92 static unsigned char macinfo_data[macinfo_data_size]
93 __attribute__ ((aligned (__alignof (Dwarf_Macro_Op_Table))));
95 static __attribute__ ((constructor)) void
96 init_macinfo_table (void)
98 MACRO_PROTO (p_udata_str, DW_FORM_udata, DW_FORM_string);
99 MACRO_PROTO (p_udata_udata, DW_FORM_udata, DW_FORM_udata);
100 MACRO_PROTO (p_none);
102 Dwarf_Macro_Op_Proto op_protos[255] =
104 [DW_MACINFO_define - 1] = p_udata_str,
105 [DW_MACINFO_undef - 1] = p_udata_str,
106 [DW_MACINFO_vendor_ext - 1] = p_udata_str,
107 [DW_MACINFO_start_file - 1] = p_udata_udata,
108 [DW_MACINFO_end_file - 1] = p_none,
109 /* If you are adding more elements to this array, increase
110 MACINFO_DATA_SIZE above. */
113 Dwarf_Macro_Op_Table *macinfo_table = (void *) macinfo_data;
114 memset (macinfo_table, 0, sizeof macinfo_data);
115 build_table (macinfo_table, op_protos);
116 macinfo_table->sec_index = IDX_debug_macinfo;
119 static Dwarf_Macro_Op_Table *
120 get_macinfo_table (Dwarf *dbg, Dwarf_Word macoff, Dwarf_Die *cudie)
122 assert (cudie != NULL);
124 Dwarf_Attribute attr_mem, *attr
125 = INTUSE(dwarf_attr) (cudie, DW_AT_stmt_list, &attr_mem);
126 Dwarf_Off line_offset = (Dwarf_Off) -1;
128 if (unlikely (INTUSE(dwarf_formudata) (attr, &line_offset) != 0))
131 Dwarf_Macro_Op_Table *table = libdw_alloc (dbg, Dwarf_Macro_Op_Table,
132 macinfo_data_size, 1);
133 memcpy (table, macinfo_data, macinfo_data_size);
135 table->offset = macoff;
136 table->sec_index = IDX_debug_macinfo;
137 table->line_offset = line_offset;
138 table->is_64bit = cudie->cu->address_size == 8;
139 table->comp_dir = __libdw_getcompdir (cudie);
144 static Dwarf_Macro_Op_Table *
145 get_table_for_offset (Dwarf *dbg, Dwarf_Word macoff,
146 const unsigned char *readp,
147 const unsigned char *const endp,
150 const unsigned char *startp = readp;
152 /* Request at least 3 bytes for header. */
153 if (readp + 3 > endp)
156 __libdw_seterrno (DWARF_E_INVALID_DWARF);
160 uint16_t version = read_2ubyte_unaligned_inc (dbg, readp);
163 __libdw_seterrno (DWARF_E_INVALID_VERSION);
167 uint8_t flags = *readp++;
168 bool is_64bit = (flags & 0x1) != 0;
170 Dwarf_Off line_offset = (Dwarf_Off) -1;
171 if ((flags & 0x2) != 0)
173 line_offset = read_addr_unaligned_inc (is_64bit ? 8 : 4, dbg, readp);
177 else if (cudie != NULL)
179 Dwarf_Attribute attr_mem, *attr
180 = INTUSE(dwarf_attr) (cudie, DW_AT_stmt_list, &attr_mem);
182 if (unlikely (INTUSE(dwarf_formudata) (attr, &line_offset) != 0))
186 /* """The macinfo entry types defined in this standard may, but
187 might not, be described in the table""".
189 I.e. these may be present. It's tempting to simply skip them,
190 but it's probably more correct to tolerate that a producer tweaks
191 the way certain opcodes are encoded, for whatever reasons. */
193 MACRO_PROTO (p_udata_str, DW_FORM_udata, DW_FORM_string);
194 MACRO_PROTO (p_udata_strp, DW_FORM_udata, DW_FORM_strp);
195 MACRO_PROTO (p_udata_udata, DW_FORM_udata, DW_FORM_udata);
196 MACRO_PROTO (p_secoffset, DW_FORM_sec_offset);
197 MACRO_PROTO (p_none);
199 Dwarf_Macro_Op_Proto op_protos[255] =
201 [DW_MACRO_GNU_define - 1] = p_udata_str,
202 [DW_MACRO_GNU_undef - 1] = p_udata_str,
203 [DW_MACRO_GNU_define_indirect - 1] = p_udata_strp,
204 [DW_MACRO_GNU_undef_indirect - 1] = p_udata_strp,
205 [DW_MACRO_GNU_start_file - 1] = p_udata_udata,
206 [DW_MACRO_GNU_end_file - 1] = p_none,
207 [DW_MACRO_GNU_transparent_include - 1] = p_secoffset,
208 /* N.B. DW_MACRO_undef_indirectx, DW_MACRO_define_indirectx
209 should be added when 130313.1 is supported. */
212 if ((flags & 0x4) != 0)
214 unsigned count = *readp++;
215 for (unsigned i = 0; i < count; ++i)
217 unsigned opcode = *readp++;
219 Dwarf_Macro_Op_Proto e;
222 get_uleb128 (e.nforms, readp, endp);
224 op_protos[opcode - 1] = e;
230 __libdw_seterrno (DWARF_E_INVALID_DWARF);
237 for (unsigned i = 1; i < 256; ++i)
238 if (op_protos[i - 1].forms != NULL)
241 /* We support at most 0xfe opcodes defined in the table, as 0xff is
242 a value that means that given opcode is not stored at all. But
243 that should be fine, as opcode 0 is not allocated. */
246 size_t macop_table_size = offsetof (Dwarf_Macro_Op_Table, table[ct]);
248 Dwarf_Macro_Op_Table *table = libdw_alloc (dbg, Dwarf_Macro_Op_Table,
249 macop_table_size, 1);
251 *table = (Dwarf_Macro_Op_Table) {
253 .sec_index = IDX_debug_macro,
254 .line_offset = line_offset,
255 .header_len = readp - startp,
257 .is_64bit = is_64bit,
259 /* NULL if CUDIE is NULL or DW_AT_comp_dir is absent. */
260 .comp_dir = __libdw_getcompdir (cudie),
262 build_table (table, op_protos);
267 static Dwarf_Macro_Op_Table *
268 cache_op_table (Dwarf *dbg, int sec_index, Dwarf_Off macoff,
269 const unsigned char *startp,
270 const unsigned char *const endp,
273 Dwarf_Macro_Op_Table fake = { .offset = macoff, .sec_index = sec_index };
274 Dwarf_Macro_Op_Table **found = tfind (&fake, &dbg->macro_ops,
279 Dwarf_Macro_Op_Table *table = sec_index == IDX_debug_macro
280 ? get_table_for_offset (dbg, macoff, startp, endp, cudie)
281 : get_macinfo_table (dbg, macoff, cudie);
286 Dwarf_Macro_Op_Table **ret = tsearch (table, &dbg->macro_ops,
288 if (unlikely (ret == NULL))
290 __libdw_seterrno (DWARF_E_NOMEM);
298 read_macros (Dwarf *dbg, int sec_index,
299 Dwarf_Off macoff, int (*callback) (Dwarf_Macro *, void *),
300 void *arg, ptrdiff_t offset, bool accept_0xff,
303 Elf_Data *d = dbg->sectiondata[sec_index];
304 if (unlikely (d == NULL || d->d_buf == NULL))
306 __libdw_seterrno (DWARF_E_NO_ENTRY);
310 if (unlikely (macoff >= d->d_size))
312 __libdw_seterrno (DWARF_E_INVALID_DWARF);
316 const unsigned char *const startp = d->d_buf + macoff;
317 const unsigned char *const endp = d->d_buf + d->d_size;
319 Dwarf_Macro_Op_Table *table = cache_op_table (dbg, sec_index, macoff,
320 startp, endp, cudie);
325 offset = table->header_len;
327 assert (offset >= 0);
328 assert (offset < endp - startp);
329 const unsigned char *readp = startp + offset;
333 unsigned int opcode = *readp++;
335 /* Nothing more to do. */
338 if (unlikely (opcode == 0xff && ! accept_0xff))
340 /* See comment below at dwarf_getmacros for explanation of
341 why we are doing this. */
342 __libdw_seterrno (DWARF_E_INVALID_OPCODE);
346 unsigned int idx = table->opcodes[opcode - 1];
349 __libdw_seterrno (DWARF_E_INVALID_OPCODE);
353 Dwarf_Macro_Op_Proto *proto = &table->table[idx];
355 /* A fake CU with bare minimum data to fool dwarf_formX into
356 doing the right thing with the attributes that we put out.
357 We arbitrarily pretend it's version 4. */
361 .offset_size = table->is_64bit ? 8 : 4,
362 .startp = (void *) startp + offset,
363 .endp = (void *) endp,
366 Dwarf_Attribute *attributes;
367 Dwarf_Attribute *attributesp = NULL;
368 Dwarf_Attribute nattributes[8];
369 if (unlikely (proto->nforms > 8))
371 attributesp = malloc (sizeof (Dwarf_Attribute) * proto->nforms);
372 if (attributesp == NULL)
374 __libdw_seterrno (DWARF_E_NOMEM);
377 attributes = attributesp;
380 attributes = &nattributes[0];
382 for (Dwarf_Word i = 0; i < proto->nforms; ++i)
384 /* We pretend this is a DW_AT_GNU_macros attribute so that
385 DW_FORM_sec_offset forms get correctly interpreted as
386 offset into .debug_macro. */
387 attributes[i].code = DW_AT_GNU_macros;
388 attributes[i].form = proto->forms[i];
389 attributes[i].valp = (void *) readp;
390 attributes[i].cu = &fake_cu;
392 size_t len = __libdw_form_val_len (&fake_cu, proto->forms[i], readp);
393 if (unlikely (len == (size_t) -1))
402 Dwarf_Macro macro = {
405 .attributes = attributes,
408 int res = callback (¯o, arg);
409 if (unlikely (attributesp != NULL))
412 if (res != DWARF_CB_OK)
413 return readp - startp;
421 - The highest bit is used for distinguishing between callers that
422 know that opcode 0xff may have one of two incompatible meanings.
423 The mask that we use for selecting this bit is
424 DWARF_GETMACROS_START.
426 - The rest of the token (31 or 63 bits) encodes address inside the
429 Besides, token value of 0 signals end of iteration and -1 is
430 reserved for signaling errors. That means it's impossible to
431 represent maximum offset of a .debug_macro unit to new-style
432 callers (which in practice decreases the permissible macro unit
433 size by another 1 byte). */
436 token_from_offset (ptrdiff_t offset, bool accept_0xff)
438 if (offset == -1 || offset == 0)
441 /* Make sure the offset didn't overflow into the flag bit. */
442 if ((offset & DWARF_GETMACROS_START) != 0)
444 __libdw_seterrno (DWARF_E_TOO_BIG);
449 offset |= DWARF_GETMACROS_START;
455 offset_from_token (ptrdiff_t token, bool *accept_0xffp)
457 *accept_0xffp = (token & DWARF_GETMACROS_START) != 0;
458 token &= ~DWARF_GETMACROS_START;
464 gnu_macros_getmacros_off (Dwarf *dbg, Dwarf_Off macoff,
465 int (*callback) (Dwarf_Macro *, void *),
466 void *arg, ptrdiff_t offset, bool accept_0xff,
469 assert (offset >= 0);
471 if (macoff >= dbg->sectiondata[IDX_debug_macro]->d_size)
473 __libdw_seterrno (DWARF_E_INVALID_OFFSET);
477 return read_macros (dbg, IDX_debug_macro, macoff,
478 callback, arg, offset, accept_0xff, cudie);
482 macro_info_getmacros_off (Dwarf *dbg, Dwarf_Off macoff,
483 int (*callback) (Dwarf_Macro *, void *),
484 void *arg, ptrdiff_t offset, Dwarf_Die *cudie)
486 assert (offset >= 0);
488 return read_macros (dbg, IDX_debug_macinfo, macoff,
489 callback, arg, offset, true, cudie);
493 dwarf_getmacros_off (Dwarf *dbg, Dwarf_Off macoff,
494 int (*callback) (Dwarf_Macro *, void *),
495 void *arg, ptrdiff_t token)
499 __libdw_seterrno (DWARF_E_NO_DWARF);
504 ptrdiff_t offset = offset_from_token (token, &accept_0xff);
505 assert (accept_0xff);
507 offset = gnu_macros_getmacros_off (dbg, macoff, callback, arg, offset,
510 return token_from_offset (offset, accept_0xff);
514 dwarf_getmacros (Dwarf_Die *cudie, int (*callback) (Dwarf_Macro *, void *),
515 void *arg, ptrdiff_t token)
519 __libdw_seterrno (DWARF_E_NO_DWARF);
523 /* This function might be called from a code that expects to see
524 DW_MACINFO_* opcodes, not DW_MACRO_{GNU_,}* ones. It is fine to
525 serve most DW_MACRO_{GNU_,}* opcodes to such code, because those
526 whose values are the same as DW_MACINFO_* ones also have the same
527 behavior. It is not very likely that a .debug_macro section
528 would only use the part of opcode space that it shares with
529 .debug_macinfo, but it is possible. Serving the opcodes that are
530 only valid in DW_MACRO_{GNU_,}* domain is OK as well, because
531 clients in general need to be ready that newer standards define
532 more opcodes, and have coping mechanisms for unfamiliar opcodes.
534 The one exception to the above rule is opcode 0xff, which has
535 concrete semantics in .debug_macinfo, but falls into vendor block
536 in .debug_macro, and can be assigned to do whatever. There is
537 some small probability that the two opcodes would look
538 superficially similar enough that a client would be confused and
539 misbehave as a result. For this reason, we refuse to serve
540 through this interface 0xff's originating from .debug_macro
541 unless the TOKEN that we obtained indicates the call originates
542 from a new-style caller. See above for details on what
543 information is encoded into tokens. */
546 ptrdiff_t offset = offset_from_token (token, &accept_0xff);
548 /* DW_AT_macro_info */
549 if (dwarf_hasattr (cudie, DW_AT_macro_info))
552 if (get_offset_from (cudie, DW_AT_macro_info, &macoff) != 0)
554 offset = macro_info_getmacros_off (cudie->cu->dbg, macoff,
555 callback, arg, offset, cudie);
559 /* DW_AT_GNU_macros, DW_AT_macros */
561 if (get_offset_from (cudie, DW_AT_GNU_macros, &macoff) != 0)
563 offset = gnu_macros_getmacros_off (cudie->cu->dbg, macoff,
564 callback, arg, offset, accept_0xff,
568 return token_from_offset (offset, accept_0xff);