e99a673109c81bb309c4a768606dc2e5e5fb22da
[deliverable/binutils-gdb.git] / include / ctf.h
1 /* CTF format description.
2 Copyright (C) 2019 Free Software Foundation, Inc.
3
4 This file is part of libctf.
5
6 libctf is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10
11 This program is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
14 See the GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; see the file COPYING. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 #ifndef _CTF_H
21 #define _CTF_H
22
23 #include <sys/types.h>
24 #include <limits.h>
25 #include <stdint.h>
26
27
28 #ifdef __cplusplus
29 extern "C"
30 {
31 #endif
32
33 /* CTF - Compact ANSI-C Type Format
34
35 This file format can be used to compactly represent the information needed
36 by a debugger to interpret the ANSI-C types used by a given program.
37 Traditionally, this kind of information is generated by the compiler when
38 invoked with the -g flag and is stored in "stabs" strings or in the more
39 modern DWARF format. CTF provides a representation of only the information
40 that is relevant to debugging a complex, optimized C program such as the
41 operating system kernel in a form that is significantly more compact than
42 the equivalent stabs or DWARF representation. The format is data-model
43 independent, so consumers do not need different code depending on whether
44 they are 32-bit or 64-bit programs; libctf automatically compensates for
45 endianness variations. CTF assumes that a standard ELF symbol table is
46 available for use in the debugger, and uses the structure and data of the
47 symbol table to avoid storing redundant information. The CTF data may be
48 compressed on disk or in memory, indicated by a bit in the header. CTF may
49 be interpreted in a raw disk file, or it may be stored in an ELF section,
50 typically named .ctf. Data structures are aligned so that a raw CTF file or
51 CTF ELF section may be manipulated using mmap(2).
52
53 The CTF file or section itself has the following structure:
54
55 +--------+--------+---------+----------+----------+-------+--------+
56 | file | type | data | function | variable | data | string |
57 | header | labels | objects | info | info | types | table |
58 +--------+--------+---------+----------+----------+-------+--------+
59
60 The file header stores a magic number and version information, encoding
61 flags, and the byte offset of each of the sections relative to the end of the
62 header itself. If the CTF data has been uniquified against another set of
63 CTF data, a reference to that data also appears in the the header. This
64 reference is the name of the label corresponding to the types uniquified
65 against.
66
67 Following the header is a list of labels, used to group the types included in
68 the data types section. Each label is accompanied by a type ID i. A given
69 label refers to the group of types whose IDs are in the range [0, i].
70
71 Data object and function records are stored in the same order as they appear
72 in the corresponding symbol table, except that symbols marked SHN_UNDEF are
73 not stored and symbols that have no type data are padded out with zeroes.
74 For each data object, the type ID (a small integer) is recorded. For each
75 function, the type ID of the return type and argument types is recorded.
76
77 Variable records (as distinct from data objects) provide a modicum of support
78 for non-ELF systems, mapping a variable name to a CTF type ID. The variable
79 names are sorted into ASCIIbetical order, permitting binary searching.
80
81 The data types section is a list of variable size records that represent each
82 type, in order by their ID. The types themselves form a directed graph,
83 where each node may contain one or more outgoing edges to other type nodes,
84 denoted by their ID.
85
86 Strings are recorded as a string table ID (0 or 1) and a byte offset into the
87 string table. String table 0 is the internal CTF string table. String table
88 1 is the external string table, which is the string table associated with the
89 ELF symbol table for this object. CTF does not record any strings that are
90 already in the symbol table, and the CTF string table does not contain any
91 duplicated strings.
92
93 If the CTF data has been merged with another parent CTF object, some outgoing
94 edges may refer to type nodes that exist in another CTF object. The debugger
95 and libctf library are responsible for connecting the appropriate objects
96 together so that the full set of types can be explored and manipulated.
97
98 This connection is done purely using the ctf_import() function. There is no
99 notation anywhere in the child CTF file indicating which parent it is
100 connected to: it is the debugger's responsibility to track this. */
101
102 #define CTF_MAX_TYPE 0xfffffffe /* Max type identifier value. */
103 #define CTF_MAX_PTYPE 0x7fffffff /* Max parent type identifier value. */
104 #define CTF_MAX_NAME 0x7fffffff /* Max offset into a string table. */
105 #define CTF_MAX_VLEN 0xffffff /* Max struct, union, enum members or args. */
106
107 /* See ctf_type_t */
108 #define CTF_MAX_SIZE 0xfffffffe /* Max size of a v2 type in bytes. */
109 #define CTF_LSIZE_SENT 0xffffffff /* Sentinel for v2 ctt_size. */
110
111 # define CTF_MAX_TYPE_V1 0xffff /* Max type identifier value. */
112 # define CTF_MAX_PTYPE_V1 0x7fff /* Max parent type identifier value. */
113 # define CTF_MAX_VLEN_V1 0x3ff /* Max struct, union, enums or args. */
114 # define CTF_MAX_SIZE_V1 0xfffe /* Max size of a type in bytes. */
115 # define CTF_LSIZE_SENT_V1 0xffff /* Sentinel for v1 ctt_size. */
116
117 /* Start of actual data structure definitions.
118
119 Every field in these structures must have corresponding code in the
120 endianness-swapping machinery in libctf/ctf-open.c. */
121
122 typedef struct ctf_preamble
123 {
124 unsigned short ctp_magic; /* Magic number (CTF_MAGIC). */
125 unsigned char ctp_version; /* Data format version number (CTF_VERSION). */
126 unsigned char ctp_flags; /* Flags (see below). */
127 } ctf_preamble_t;
128
129 typedef struct ctf_header
130 {
131 ctf_preamble_t cth_preamble;
132 uint32_t cth_parlabel; /* Ref to name of parent lbl uniq'd against. */
133 uint32_t cth_parname; /* Ref to basename of parent. */
134 uint32_t cth_lbloff; /* Offset of label section. */
135 uint32_t cth_objtoff; /* Offset of object section. */
136 uint32_t cth_funcoff; /* Offset of function section. */
137 uint32_t cth_varoff; /* Offset of variable section. */
138 uint32_t cth_typeoff; /* Offset of type section. */
139 uint32_t cth_stroff; /* Offset of string section. */
140 uint32_t cth_strlen; /* Length of string section in bytes. */
141 } ctf_header_t;
142
143 #define cth_magic cth_preamble.ctp_magic
144 #define cth_version cth_preamble.ctp_version
145 #define cth_flags cth_preamble.ctp_flags
146
147 #define CTF_MAGIC 0xdff2 /* Magic number identifying header. */
148
149 /* Data format version number. */
150
151 /* v1 upgraded to v2 is not quite the same as native v2 (the boundary between
152 parent and child types is different), and you can write it out again via
153 ctf_compress_write(), so we must track whether the thing was originally v1 or
154 not. If we were writing the header from scratch, we would add a *pair* of
155 version number fields to allow for this, but this will do for now. (A flag
156 will not do, because we need to encode both the version we came from and the
157 version we went to, not just "we were upgraded".) */
158
159 # define CTF_VERSION_1 1
160 # define CTF_VERSION_1_UPGRADED_3 2
161 # define CTF_VERSION_2 3
162
163 #define CTF_VERSION_3 4
164 #define CTF_VERSION CTF_VERSION_3 /* Current version. */
165
166 #define CTF_F_COMPRESS 0x1 /* Data buffer is compressed by libctf. */
167
168 typedef struct ctf_lblent
169 {
170 uint32_t ctl_label; /* Ref to name of label. */
171 uint32_t ctl_type; /* Last type associated with this label. */
172 } ctf_lblent_t;
173
174 typedef struct ctf_varent
175 {
176 uint32_t ctv_name; /* Reference to name in string table. */
177 uint32_t ctv_type; /* Index of type of this variable. */
178 } ctf_varent_t;
179
180 /* In format v2, type sizes, measured in bytes, come in two flavours. Nearly
181 all of them fit into a (UINT_MAX - 1), and thus can be stored in the ctt_size
182 member of a ctf_stype_t. The maximum value for these sizes is CTF_MAX_SIZE.
183 Types larger than this must be stored in the ctf_lsize member of a
184 ctf_type_t. Use of this member is indicated by the presence of
185 CTF_LSIZE_SENT in ctt_size. */
186
187 /* In v1, the same applies, only the limit is (USHRT_MAX - 1) and
188 CTF_MAX_SIZE_V1, and CTF_LSIZE_SENT_V1 is the sentinel. */
189
190 typedef struct ctf_stype_v1
191 {
192 uint32_t ctt_name; /* Reference to name in string table. */
193 unsigned short ctt_info; /* Encoded kind, variant length (see below). */
194 #ifndef __GNUC__
195 union
196 {
197 unsigned short _size; /* Size of entire type in bytes. */
198 unsigned short _type; /* Reference to another type. */
199 } _u;
200 #else
201 __extension__
202 union
203 {
204 unsigned short ctt_size; /* Size of entire type in bytes. */
205 unsigned short ctt_type; /* Reference to another type. */
206 };
207 #endif
208 } ctf_stype_v1_t;
209
210 typedef struct ctf_type_v1
211 {
212 uint32_t ctt_name; /* Reference to name in string table. */
213 unsigned short ctt_info; /* Encoded kind, variant length (see below). */
214 #ifndef __GNUC__
215 union
216 {
217 unsigned short _size; /* Always CTF_LSIZE_SENT_V1. */
218 unsigned short _type; /* Do not use. */
219 } _u;
220 #else
221 __extension__
222 union
223 {
224 unsigned short ctt_size; /* Always CTF_LSIZE_SENT_V1. */
225 unsigned short ctt_type; /* Do not use. */
226 };
227 #endif
228 uint32_t ctt_lsizehi; /* High 32 bits of type size in bytes. */
229 uint32_t ctt_lsizelo; /* Low 32 bits of type size in bytes. */
230 } ctf_type_v1_t;
231
232
233 typedef struct ctf_stype
234 {
235 uint32_t ctt_name; /* Reference to name in string table. */
236 uint32_t ctt_info; /* Encoded kind, variant length (see below). */
237 #ifndef __GNUC__
238 union
239 {
240 uint32_t _size; /* Size of entire type in bytes. */
241 uint32_t _type; /* Reference to another type. */
242 } _u;
243 #else
244 __extension__
245 union
246 {
247 uint32_t ctt_size; /* Size of entire type in bytes. */
248 uint32_t ctt_type; /* Reference to another type. */
249 };
250 #endif
251 } ctf_stype_t;
252
253 typedef struct ctf_type
254 {
255 uint32_t ctt_name; /* Reference to name in string table. */
256 uint32_t ctt_info; /* Encoded kind, variant length (see below). */
257 #ifndef __GNUC__
258 union
259 {
260 uint32_t _size; /* Always CTF_LSIZE_SENT. */
261 uint32_t _type; /* Do not use. */
262 } _u;
263 #else
264 __extension__
265 union
266 {
267 uint32_t ctt_size; /* Always CTF_LSIZE_SENT. */
268 uint32_t ctt_type; /* Do not use. */
269 };
270 #endif
271 uint32_t ctt_lsizehi; /* High 32 bits of type size in bytes. */
272 uint32_t ctt_lsizelo; /* Low 32 bits of type size in bytes. */
273 } ctf_type_t;
274
275 #ifndef __GNUC__
276 #define ctt_size _u._size /* For fundamental types that have a size. */
277 #define ctt_type _u._type /* For types that reference another type. */
278 #endif
279
280 /* The following macros and inline functions compose and decompose values for
281 ctt_info and ctt_name, as well as other structures that contain name
282 references. Use outside libdtrace-ctf itself is explicitly for access to CTF
283 files directly: types returned from the library will always appear to be
284 CTF_V2.
285
286 v1: (transparently upgraded to v2 at open time: may be compiled out of the
287 library)
288 ------------------------
289 ctt_info: | kind | isroot | vlen |
290 ------------------------
291 15 11 10 9 0
292
293 v2:
294 ------------------------
295 ctt_info: | kind | isroot | vlen |
296 ------------------------
297 31 26 25 24 0
298
299 CTF_V1 and V2 _INFO_VLEN have the same interface:
300
301 kind = CTF_*_INFO_KIND(c.ctt_info); <-- CTF_K_* value (see below)
302 vlen = CTF_*_INFO_VLEN(fp, c.ctt_info); <-- length of variable data list
303
304 stid = CTF_NAME_STID(c.ctt_name); <-- string table id number (0 or 1)
305 offset = CTF_NAME_OFFSET(c.ctt_name); <-- string table byte offset
306
307 c.ctt_info = CTF_TYPE_INFO(kind, vlen);
308 c.ctt_name = CTF_TYPE_NAME(stid, offset); */
309
310 # define CTF_V1_INFO_KIND(info) (((info) & 0xf800) >> 11)
311 # define CTF_V1_INFO_ISROOT(info) (((info) & 0x0400) >> 10)
312 # define CTF_V1_INFO_VLEN(info) (((info) & CTF_MAX_VLEN_V1))
313
314 #define CTF_V2_INFO_KIND(info) (((info) & 0xfc000000) >> 26)
315 #define CTF_V2_INFO_ISROOT(info) (((info) & 0x2000000) >> 25)
316 #define CTF_V2_INFO_VLEN(info) (((info) & CTF_MAX_VLEN))
317
318 #define CTF_NAME_STID(name) ((name) >> 31)
319 #define CTF_NAME_OFFSET(name) ((name) & CTF_MAX_NAME)
320
321 /* V2 only. */
322 #define CTF_TYPE_INFO(kind, isroot, vlen) \
323 (((kind) << 26) | (((isroot) ? 1 : 0) << 25) | ((vlen) & CTF_MAX_VLEN))
324
325 #define CTF_TYPE_NAME(stid, offset) \
326 (((stid) << 31) | ((offset) & CTF_MAX_NAME))
327
328 /* The next set of macros are for public consumption only. Not used internally,
329 since the relevant type boundary is dependent upon the version of the file at
330 *opening* time, not the version after transparent upgrade. Use
331 ctf_type_isparent() / ctf_type_ischild() for that. */
332
333 #define CTF_V2_TYPE_ISPARENT(fp, id) ((id) <= CTF_MAX_PTYPE)
334 #define CTF_V2_TYPE_ISCHILD(fp, id) ((id) > CTF_MAX_PTYPE)
335 #define CTF_V2_TYPE_TO_INDEX(id) ((id) & CTF_MAX_PTYPE)
336 #define CTF_V2_INDEX_TO_TYPE(id, child) ((child) ? ((id) | (CTF_MAX_PTYPE+1)) : (id))
337
338 # define CTF_V1_TYPE_ISPARENT(fp, id) ((id) <= CTF_MAX_PTYPE_V1)
339 # define CTF_V1_TYPE_ISCHILD(fp, id) ((id) > CTF_MAX_PTYPE_V1)
340 # define CTF_V1_TYPE_TO_INDEX(id) ((id) & CTF_MAX_PTYPE_V1)
341 # define CTF_V1_INDEX_TO_TYPE(id, child) ((child) ? ((id) | (CTF_MAX_PTYPE_V1+1)) : (id))
342
343 /* Valid for both V1 and V2. */
344 #define CTF_TYPE_LSIZE(cttp) \
345 (((uint64_t)(cttp)->ctt_lsizehi) << 32 | (cttp)->ctt_lsizelo)
346 #define CTF_SIZE_TO_LSIZE_HI(size) ((uint32_t)((uint64_t)(size) >> 32))
347 #define CTF_SIZE_TO_LSIZE_LO(size) ((uint32_t)(size))
348
349 #define CTF_STRTAB_0 0 /* String table id 0 (in-CTF). */
350 #define CTF_STRTAB_1 1 /* String table id 1 (ELF strtab). */
351
352 /* Values for CTF_TYPE_KIND(). If the kind has an associated data list,
353 CTF_INFO_VLEN() will extract the number of elements in the list, and
354 the type of each element is shown in the comments below. */
355
356 #define CTF_K_UNKNOWN 0 /* Unknown type (used for padding). */
357 #define CTF_K_INTEGER 1 /* Variant data is CTF_INT_DATA (see below). */
358 #define CTF_K_FLOAT 2 /* Variant data is CTF_FP_DATA (see below). */
359 #define CTF_K_POINTER 3 /* ctt_type is referenced type. */
360 #define CTF_K_ARRAY 4 /* Variant data is single ctf_array_t. */
361 #define CTF_K_FUNCTION 5 /* ctt_type is return type, variant data is
362 list of argument types (unsigned short's for v1,
363 uint32_t's for v2). */
364 #define CTF_K_STRUCT 6 /* Variant data is list of ctf_member_t's. */
365 #define CTF_K_UNION 7 /* Variant data is list of ctf_member_t's. */
366 #define CTF_K_ENUM 8 /* Variant data is list of ctf_enum_t's. */
367 #define CTF_K_FORWARD 9 /* No additional data; ctt_name is tag. */
368 #define CTF_K_TYPEDEF 10 /* ctt_type is referenced type. */
369 #define CTF_K_VOLATILE 11 /* ctt_type is base type. */
370 #define CTF_K_CONST 12 /* ctt_type is base type. */
371 #define CTF_K_RESTRICT 13 /* ctt_type is base type. */
372 #define CTF_K_SLICE 14 /* Variant data is a ctf_slice_t. */
373
374 #define CTF_K_MAX 63 /* Maximum possible (V2) CTF_K_* value. */
375
376 /* Values for ctt_type when kind is CTF_K_INTEGER. The flags, offset in bits,
377 and size in bits are encoded as a single word using the following macros.
378 (However, you can also encode the offset and bitness in a slice.) */
379
380 #define CTF_INT_ENCODING(data) (((data) & 0xff000000) >> 24)
381 #define CTF_INT_OFFSET(data) (((data) & 0x00ff0000) >> 16)
382 #define CTF_INT_BITS(data) (((data) & 0x0000ffff))
383
384 #define CTF_INT_DATA(encoding, offset, bits) \
385 (((encoding) << 24) | ((offset) << 16) | (bits))
386
387 #define CTF_INT_SIGNED 0x01 /* Integer is signed (otherwise unsigned). */
388 #define CTF_INT_CHAR 0x02 /* Character display format. */
389 #define CTF_INT_BOOL 0x04 /* Boolean display format. */
390 #define CTF_INT_VARARGS 0x08 /* Varargs display format. */
391
392 /* Use CTF_CHAR to produce a char that agrees with the system's native
393 char signedness. */
394 #if CHAR_MIN == 0
395 # define CTF_CHAR (CTF_INT_CHAR)
396 #else
397 # define CTF_CHAR (CTF_INT_CHAR | CTF_INT_SIGNED)
398 #endif
399
400 /* Values for ctt_type when kind is CTF_K_FLOAT. The encoding, offset in bits,
401 and size in bits are encoded as a single word using the following macros.
402 (However, you can also encode the offset and bitness in a slice.) */
403
404 #define CTF_FP_ENCODING(data) (((data) & 0xff000000) >> 24)
405 #define CTF_FP_OFFSET(data) (((data) & 0x00ff0000) >> 16)
406 #define CTF_FP_BITS(data) (((data) & 0x0000ffff))
407
408 #define CTF_FP_DATA(encoding, offset, bits) \
409 (((encoding) << 24) | ((offset) << 16) | (bits))
410
411 /* Variant data when kind is CTF_K_FLOAT is an encoding in the top eight bits. */
412 #define CTF_FP_ENCODING(data) (((data) & 0xff000000) >> 24)
413
414 #define CTF_FP_SINGLE 1 /* IEEE 32-bit float encoding. */
415 #define CTF_FP_DOUBLE 2 /* IEEE 64-bit float encoding. */
416 #define CTF_FP_CPLX 3 /* Complex encoding. */
417 #define CTF_FP_DCPLX 4 /* Double complex encoding. */
418 #define CTF_FP_LDCPLX 5 /* Long double complex encoding. */
419 #define CTF_FP_LDOUBLE 6 /* Long double encoding. */
420 #define CTF_FP_INTRVL 7 /* Interval (2x32-bit) encoding. */
421 #define CTF_FP_DINTRVL 8 /* Double interval (2x64-bit) encoding. */
422 #define CTF_FP_LDINTRVL 9 /* Long double interval (2x128-bit) encoding. */
423 #define CTF_FP_IMAGRY 10 /* Imaginary (32-bit) encoding. */
424 #define CTF_FP_DIMAGRY 11 /* Long imaginary (64-bit) encoding. */
425 #define CTF_FP_LDIMAGRY 12 /* Long double imaginary (128-bit) encoding. */
426
427 #define CTF_FP_MAX 12 /* Maximum possible CTF_FP_* value */
428
429 /* A slice increases the offset and reduces the bitness of the referenced
430 ctt_type, which must be a type which has an encoding (fp, int, or enum). We
431 also store the referenced type in here, because it is easier to keep the
432 ctt_size correct for the slice than to shuffle the size into here and keep
433 the ctt_type where it is for other types. */
434
435 typedef struct ctf_slice
436 {
437 uint32_t cts_type;
438 unsigned char cts_offset;
439 unsigned char cts_bits;
440 } ctf_slice_t;
441
442 typedef struct ctf_array_v1
443 {
444 unsigned short cta_contents; /* Reference to type of array contents. */
445 unsigned short cta_index; /* Reference to type of array index. */
446 uint32_t cta_nelems; /* Number of elements. */
447 } ctf_array_v1_t;
448
449 typedef struct ctf_array
450 {
451 uint32_t cta_contents; /* Reference to type of array contents. */
452 uint32_t cta_index; /* Reference to type of array index. */
453 uint32_t cta_nelems; /* Number of elements. */
454 } ctf_array_t;
455
456 /* Most structure members have bit offsets that can be expressed using a short.
457 Some don't. ctf_member_t is used for structs which cannot contain any of
458 these large offsets, whereas ctf_lmember_t is used in the latter case. If
459 any member of a given struct has an offset that cannot be expressed using a
460 uint32_t, all members will be stored as type ctf_lmember_t. This is expected
461 to be very rare (but nonetheless possible). */
462
463 #define CTF_LSTRUCT_THRESH 536870912
464
465 /* In v1, the same is true, except that lmembers are used for structs >= 8192
466 bytes in size. (The ordering of members in the ctf_member_* structures is
467 different to improve padding.) */
468
469 #define CTF_LSTRUCT_THRESH_V1 8192
470
471 typedef struct ctf_member_v1
472 {
473 uint32_t ctm_name; /* Reference to name in string table. */
474 unsigned short ctm_type; /* Reference to type of member. */
475 unsigned short ctm_offset; /* Offset of this member in bits. */
476 } ctf_member_v1_t;
477
478 typedef struct ctf_lmember_v1
479 {
480 uint32_t ctlm_name; /* Reference to name in string table. */
481 unsigned short ctlm_type; /* Reference to type of member. */
482 unsigned short ctlm_pad; /* Padding. */
483 uint32_t ctlm_offsethi; /* High 32 bits of member offset in bits. */
484 uint32_t ctlm_offsetlo; /* Low 32 bits of member offset in bits. */
485 } ctf_lmember_v1_t;
486
487 typedef struct ctf_member_v2
488 {
489 uint32_t ctm_name; /* Reference to name in string table. */
490 uint32_t ctm_offset; /* Offset of this member in bits. */
491 uint32_t ctm_type; /* Reference to type of member. */
492 } ctf_member_t;
493
494 typedef struct ctf_lmember_v2
495 {
496 uint32_t ctlm_name; /* Reference to name in string table. */
497 uint32_t ctlm_offsethi; /* High 32 bits of member offset in bits. */
498 uint32_t ctlm_type; /* Reference to type of member. */
499 uint32_t ctlm_offsetlo; /* Low 32 bits of member offset in bits. */
500 } ctf_lmember_t;
501
502 #define CTF_LMEM_OFFSET(ctlmp) \
503 (((uint64_t)(ctlmp)->ctlm_offsethi) << 32 | (ctlmp)->ctlm_offsetlo)
504 #define CTF_OFFSET_TO_LMEMHI(offset) ((uint32_t)((uint64_t)(offset) >> 32))
505 #define CTF_OFFSET_TO_LMEMLO(offset) ((uint32_t)(offset))
506
507 typedef struct ctf_enum
508 {
509 uint32_t cte_name; /* Reference to name in string table. */
510 int32_t cte_value; /* Value associated with this name. */
511 } ctf_enum_t;
512
513 /* The ctf_archive is a collection of ctf_file_t's stored together. The format
514 is suitable for mmap()ing: this control structure merely describes the
515 mmap()ed archive (and overlaps the first few bytes of it), hence the
516 greater care taken with integral types. All CTF files in an archive
517 must have the same data model. (This is not validated.)
518
519 All integers in this structure are stored in little-endian byte order.
520
521 The code relies on the fact that everything in this header is a uint64_t
522 and thus the header needs no padding (in particular, that no padding is
523 needed between ctfa_ctfs and the unnamed ctfa_archive_modent array
524 that follows it).
525
526 This is *not* the same as the data structure returned by the ctf_arc_*()
527 functions: this is the low-level on-disk representation. */
528
529 #define CTFA_MAGIC 0x8b47f2a4d7623eeb /* Random. */
530 struct ctf_archive
531 {
532 /* Magic number. (In loaded files, overwritten with the file size
533 so ctf_arc_close() knows how much to munmap()). */
534 uint64_t ctfa_magic;
535
536 /* CTF data model. */
537 uint64_t ctfa_model;
538
539 /* Number of CTF files in the archive. */
540 uint64_t ctfa_nfiles;
541
542 /* Offset of the name table. */
543 uint64_t ctfa_names;
544
545 /* Offset of the CTF table. Each element starts with a size (a uint64_t
546 in network byte order) then a ctf_file_t of that size. */
547 uint64_t ctfa_ctfs;
548 };
549
550 /* An array of ctfa_nnamed of this structure lies at
551 ctf_archive[ctf_archive->ctfa_modents] and gives the ctfa_ctfs or
552 ctfa_names-relative offsets of each name or ctf_file_t. */
553
554 typedef struct ctf_archive_modent
555 {
556 uint64_t name_offset;
557 uint64_t ctf_offset;
558 } ctf_archive_modent_t;
559
560 #ifdef __cplusplus
561 }
562 #endif
563
564 #endif /* _CTF_H */
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