--- /dev/null
+/* CTF format description.
+ Copyright (C) 2019 Free Software Foundation, Inc.
+
+ This file is part of libctf.
+
+ libctf is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free
+ Software Foundation; either version 3, or (at your option) any later
+ version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; see the file COPYING. If not see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _CTF_H
+#define _CTF_H
+
+#include <sys/types.h>
+#include <limits.h>
+#include <stdint.h>
+
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/* CTF - Compact ANSI-C Type Format
+
+ This file format can be used to compactly represent the information needed
+ by a debugger to interpret the ANSI-C types used by a given program.
+ Traditionally, this kind of information is generated by the compiler when
+ invoked with the -g flag and is stored in "stabs" strings or in the more
+ modern DWARF format. CTF provides a representation of only the information
+ that is relevant to debugging a complex, optimized C program such as the
+ operating system kernel in a form that is significantly more compact than
+ the equivalent stabs or DWARF representation. The format is data-model
+ independent, so consumers do not need different code depending on whether
+ they are 32-bit or 64-bit programs; libctf automatically compensates for
+ endianness variations. CTF assumes that a standard ELF symbol table is
+ available for use in the debugger, and uses the structure and data of the
+ symbol table to avoid storing redundant information. The CTF data may be
+ compressed on disk or in memory, indicated by a bit in the header. CTF may
+ be interpreted in a raw disk file, or it may be stored in an ELF section,
+ typically named .ctf. Data structures are aligned so that a raw CTF file or
+ CTF ELF section may be manipulated using mmap(2).
+
+ The CTF file or section itself has the following structure:
+
+ +--------+--------+---------+----------+----------+-------+--------+
+ | file | type | data | function | variable | data | string |
+ | header | labels | objects | info | info | types | table |
+ +--------+--------+---------+----------+----------+-------+--------+
+
+ The file header stores a magic number and version information, encoding
+ flags, and the byte offset of each of the sections relative to the end of the
+ header itself. If the CTF data has been uniquified against another set of
+ CTF data, a reference to that data also appears in the the header. This
+ reference is the name of the label corresponding to the types uniquified
+ against.
+
+ Following the header is a list of labels, used to group the types included in
+ the data types section. Each label is accompanied by a type ID i. A given
+ label refers to the group of types whose IDs are in the range [0, i].
+
+ Data object and function records are stored in the same order as they appear
+ in the corresponding symbol table, except that symbols marked SHN_UNDEF are
+ not stored and symbols that have no type data are padded out with zeroes.
+ For each data object, the type ID (a small integer) is recorded. For each
+ function, the type ID of the return type and argument types is recorded.
+
+ Variable records (as distinct from data objects) provide a modicum of support
+ for non-ELF systems, mapping a variable name to a CTF type ID. The variable
+ names are sorted into ASCIIbetical order, permitting binary searching.
+
+ The data types section is a list of variable size records that represent each
+ type, in order by their ID. The types themselves form a directed graph,
+ where each node may contain one or more outgoing edges to other type nodes,
+ denoted by their ID.
+
+ Strings are recorded as a string table ID (0 or 1) and a byte offset into the
+ string table. String table 0 is the internal CTF string table. String table
+ 1 is the external string table, which is the string table associated with the
+ ELF symbol table for this object. CTF does not record any strings that are
+ already in the symbol table, and the CTF string table does not contain any
+ duplicated strings.
+
+ If the CTF data has been merged with another parent CTF object, some outgoing
+ edges may refer to type nodes that exist in another CTF object. The debugger
+ and libctf library are responsible for connecting the appropriate objects
+ together so that the full set of types can be explored and manipulated.
+
+ This connection is done purely using the ctf_import() function. There is no
+ notation anywhere in the child CTF file indicating which parent it is
+ connected to: it is the debugger's responsibility to track this. */
+
+#define CTF_MAX_TYPE 0xfffffffe /* Max type identifier value. */
+#define CTF_MAX_PTYPE 0x7fffffff /* Max parent type identifier value. */
+#define CTF_MAX_NAME 0x7fffffff /* Max offset into a string table. */
+#define CTF_MAX_VLEN 0xffffff /* Max struct, union, enum members or args. */
+
+/* See ctf_type_t */
+#define CTF_MAX_SIZE 0xfffffffe /* Max size of a v2 type in bytes. */
+#define CTF_LSIZE_SENT 0xffffffff /* Sentinel for v2 ctt_size. */
+
+# define CTF_MAX_TYPE_V1 0xffff /* Max type identifier value. */
+# define CTF_MAX_PTYPE_V1 0x7fff /* Max parent type identifier value. */
+# define CTF_MAX_VLEN_V1 0x3ff /* Max struct, union, enums or args. */
+# define CTF_MAX_SIZE_V1 0xfffe /* Max size of a type in bytes. */
+# define CTF_LSIZE_SENT_V1 0xffff /* Sentinel for v1 ctt_size. */
+
+ /* Start of actual data structure definitions.
+
+ Every field in these structures must have corresponding code in the
+ endianness-swapping machinery in libctf/ctf-open.c. */
+
+typedef struct ctf_preamble
+{
+ unsigned short ctp_magic; /* Magic number (CTF_MAGIC). */
+ unsigned char ctp_version; /* Data format version number (CTF_VERSION). */
+ unsigned char ctp_flags; /* Flags (see below). */
+} ctf_preamble_t;
+
+typedef struct ctf_header
+{
+ ctf_preamble_t cth_preamble;
+ uint32_t cth_parlabel; /* Ref to name of parent lbl uniq'd against. */
+ uint32_t cth_parname; /* Ref to basename of parent. */
+ uint32_t cth_lbloff; /* Offset of label section. */
+ uint32_t cth_objtoff; /* Offset of object section. */
+ uint32_t cth_funcoff; /* Offset of function section. */
+ uint32_t cth_varoff; /* Offset of variable section. */
+ uint32_t cth_typeoff; /* Offset of type section. */
+ uint32_t cth_stroff; /* Offset of string section. */
+ uint32_t cth_strlen; /* Length of string section in bytes. */
+} ctf_header_t;
+
+#define cth_magic cth_preamble.ctp_magic
+#define cth_version cth_preamble.ctp_version
+#define cth_flags cth_preamble.ctp_flags
+
+#define CTF_MAGIC 0xdff2 /* Magic number identifying header. */
+
+/* Data format version number. */
+
+/* v1 upgraded to v2 is not quite the same as native v2 (the boundary between
+ parent and child types is different), and you can write it out again via
+ ctf_compress_write(), so we must track whether the thing was originally v1 or
+ not. If we were writing the header from scratch, we would add a *pair* of
+ version number fields to allow for this, but this will do for now. (A flag
+ will not do, because we need to encode both the version we came from and the
+ version we went to, not just "we were upgraded".) */
+
+# define CTF_VERSION_1 1
+# define CTF_VERSION_1_UPGRADED_3 2
+# define CTF_VERSION_2 3
+
+#define CTF_VERSION_3 4
+#define CTF_VERSION CTF_VERSION_3 /* Current version. */
+
+#define CTF_F_COMPRESS 0x1 /* Data buffer is compressed by libctf. */
+
+typedef struct ctf_lblent
+{
+ uint32_t ctl_label; /* Ref to name of label. */
+ uint32_t ctl_type; /* Last type associated with this label. */
+} ctf_lblent_t;
+
+typedef struct ctf_varent
+{
+ uint32_t ctv_name; /* Reference to name in string table. */
+ uint32_t ctv_type; /* Index of type of this variable. */
+} ctf_varent_t;
+
+/* In format v2, type sizes, measured in bytes, come in two flavours. Nearly
+ all of them fit into a (UINT_MAX - 1), and thus can be stored in the ctt_size
+ member of a ctf_stype_t. The maximum value for these sizes is CTF_MAX_SIZE.
+ Types larger than this must be stored in the ctf_lsize member of a
+ ctf_type_t. Use of this member is indicated by the presence of
+ CTF_LSIZE_SENT in ctt_size. */
+
+/* In v1, the same applies, only the limit is (USHRT_MAX - 1) and
+ CTF_MAX_SIZE_V1, and CTF_LSIZE_SENT_V1 is the sentinel. */
+
+typedef struct ctf_stype_v1
+{
+ uint32_t ctt_name; /* Reference to name in string table. */
+ unsigned short ctt_info; /* Encoded kind, variant length (see below). */
+#ifndef __GNUC__
+ union
+ {
+ unsigned short _size; /* Size of entire type in bytes. */
+ unsigned short _type; /* Reference to another type. */
+ } _u;
+#else
+ __extension__
+ union
+ {
+ unsigned short ctt_size; /* Size of entire type in bytes. */
+ unsigned short ctt_type; /* Reference to another type. */
+ };
+#endif
+} ctf_stype_v1_t;
+
+typedef struct ctf_type_v1
+{
+ uint32_t ctt_name; /* Reference to name in string table. */
+ unsigned short ctt_info; /* Encoded kind, variant length (see below). */
+#ifndef __GNUC__
+ union
+ {
+ unsigned short _size; /* Always CTF_LSIZE_SENT_V1. */
+ unsigned short _type; /* Do not use. */
+ } _u;
+#else
+ __extension__
+ union
+ {
+ unsigned short ctt_size; /* Always CTF_LSIZE_SENT_V1. */
+ unsigned short ctt_type; /* Do not use. */
+ };
+#endif
+ uint32_t ctt_lsizehi; /* High 32 bits of type size in bytes. */
+ uint32_t ctt_lsizelo; /* Low 32 bits of type size in bytes. */
+} ctf_type_v1_t;
+
+
+typedef struct ctf_stype
+{
+ uint32_t ctt_name; /* Reference to name in string table. */
+ uint32_t ctt_info; /* Encoded kind, variant length (see below). */
+#ifndef __GNUC__
+ union
+ {
+ uint32_t _size; /* Size of entire type in bytes. */
+ uint32_t _type; /* Reference to another type. */
+ } _u;
+#else
+ __extension__
+ union
+ {
+ uint32_t ctt_size; /* Size of entire type in bytes. */
+ uint32_t ctt_type; /* Reference to another type. */
+ };
+#endif
+} ctf_stype_t;
+
+typedef struct ctf_type
+{
+ uint32_t ctt_name; /* Reference to name in string table. */
+ uint32_t ctt_info; /* Encoded kind, variant length (see below). */
+#ifndef __GNUC__
+union
+ {
+ uint32_t _size; /* Always CTF_LSIZE_SENT. */
+ uint32_t _type; /* Do not use. */
+ } _u;
+#else
+ __extension__
+ union
+ {
+ uint32_t ctt_size; /* Always CTF_LSIZE_SENT. */
+ uint32_t ctt_type; /* Do not use. */
+ };
+#endif
+ uint32_t ctt_lsizehi; /* High 32 bits of type size in bytes. */
+ uint32_t ctt_lsizelo; /* Low 32 bits of type size in bytes. */
+} ctf_type_t;
+
+#ifndef __GNUC__
+#define ctt_size _u._size /* For fundamental types that have a size. */
+#define ctt_type _u._type /* For types that reference another type. */
+#endif
+
+/* The following macros and inline functions compose and decompose values for
+ ctt_info and ctt_name, as well as other structures that contain name
+ references. Use outside libdtrace-ctf itself is explicitly for access to CTF
+ files directly: types returned from the library will always appear to be
+ CTF_V2.
+
+ v1: (transparently upgraded to v2 at open time: may be compiled out of the
+ library)
+ ------------------------
+ ctt_info: | kind | isroot | vlen |
+ ------------------------
+ 15 11 10 9 0
+
+ v2:
+ ------------------------
+ ctt_info: | kind | isroot | vlen |
+ ------------------------
+ 31 26 25 24 0
+
+ CTF_V1 and V2 _INFO_VLEN have the same interface:
+
+ kind = CTF_*_INFO_KIND(c.ctt_info); <-- CTF_K_* value (see below)
+ vlen = CTF_*_INFO_VLEN(fp, c.ctt_info); <-- length of variable data list
+
+ stid = CTF_NAME_STID(c.ctt_name); <-- string table id number (0 or 1)
+ offset = CTF_NAME_OFFSET(c.ctt_name); <-- string table byte offset
+
+ c.ctt_info = CTF_TYPE_INFO(kind, vlen);
+ c.ctt_name = CTF_TYPE_NAME(stid, offset); */
+
+# define CTF_V1_INFO_KIND(info) (((info) & 0xf800) >> 11)
+# define CTF_V1_INFO_ISROOT(info) (((info) & 0x0400) >> 10)
+# define CTF_V1_INFO_VLEN(info) (((info) & CTF_MAX_VLEN_V1))
+
+#define CTF_V2_INFO_KIND(info) (((info) & 0xfc000000) >> 26)
+#define CTF_V2_INFO_ISROOT(info) (((info) & 0x2000000) >> 25)
+#define CTF_V2_INFO_VLEN(info) (((info) & CTF_MAX_VLEN))
+
+#define CTF_NAME_STID(name) ((name) >> 31)
+#define CTF_NAME_OFFSET(name) ((name) & CTF_MAX_NAME)
+
+/* V2 only. */
+#define CTF_TYPE_INFO(kind, isroot, vlen) \
+ (((kind) << 26) | (((isroot) ? 1 : 0) << 25) | ((vlen) & CTF_MAX_VLEN))
+
+#define CTF_TYPE_NAME(stid, offset) \
+ (((stid) << 31) | ((offset) & CTF_MAX_NAME))
+
+/* The next set of macros are for public consumption only. Not used internally,
+ since the relevant type boundary is dependent upon the version of the file at
+ *opening* time, not the version after transparent upgrade. Use
+ ctf_type_isparent() / ctf_type_ischild() for that. */
+
+#define CTF_V2_TYPE_ISPARENT(fp, id) ((id) <= CTF_MAX_PTYPE)
+#define CTF_V2_TYPE_ISCHILD(fp, id) ((id) > CTF_MAX_PTYPE)
+#define CTF_V2_TYPE_TO_INDEX(id) ((id) & CTF_MAX_PTYPE)
+#define CTF_V2_INDEX_TO_TYPE(id, child) ((child) ? ((id) | (CTF_MAX_PTYPE+1)) : (id))
+
+# define CTF_V1_TYPE_ISPARENT(fp, id) ((id) <= CTF_MAX_PTYPE_V1)
+# define CTF_V1_TYPE_ISCHILD(fp, id) ((id) > CTF_MAX_PTYPE_V1)
+# define CTF_V1_TYPE_TO_INDEX(id) ((id) & CTF_MAX_PTYPE_V1)
+# define CTF_V1_INDEX_TO_TYPE(id, child) ((child) ? ((id) | (CTF_MAX_PTYPE_V1+1)) : (id))
+
+/* Valid for both V1 and V2. */
+#define CTF_TYPE_LSIZE(cttp) \
+ (((uint64_t)(cttp)->ctt_lsizehi) << 32 | (cttp)->ctt_lsizelo)
+#define CTF_SIZE_TO_LSIZE_HI(size) ((uint32_t)((uint64_t)(size) >> 32))
+#define CTF_SIZE_TO_LSIZE_LO(size) ((uint32_t)(size))
+
+#define CTF_STRTAB_0 0 /* String table id 0 (in-CTF). */
+#define CTF_STRTAB_1 1 /* String table id 1 (ELF strtab). */
+
+/* Values for CTF_TYPE_KIND(). If the kind has an associated data list,
+ CTF_INFO_VLEN() will extract the number of elements in the list, and
+ the type of each element is shown in the comments below. */
+
+#define CTF_K_UNKNOWN 0 /* Unknown type (used for padding). */
+#define CTF_K_INTEGER 1 /* Variant data is CTF_INT_DATA (see below). */
+#define CTF_K_FLOAT 2 /* Variant data is CTF_FP_DATA (see below). */
+#define CTF_K_POINTER 3 /* ctt_type is referenced type. */
+#define CTF_K_ARRAY 4 /* Variant data is single ctf_array_t. */
+#define CTF_K_FUNCTION 5 /* ctt_type is return type, variant data is
+ list of argument types (unsigned short's for v1,
+ uint32_t's for v2). */
+#define CTF_K_STRUCT 6 /* Variant data is list of ctf_member_t's. */
+#define CTF_K_UNION 7 /* Variant data is list of ctf_member_t's. */
+#define CTF_K_ENUM 8 /* Variant data is list of ctf_enum_t's. */
+#define CTF_K_FORWARD 9 /* No additional data; ctt_name is tag. */
+#define CTF_K_TYPEDEF 10 /* ctt_type is referenced type. */
+#define CTF_K_VOLATILE 11 /* ctt_type is base type. */
+#define CTF_K_CONST 12 /* ctt_type is base type. */
+#define CTF_K_RESTRICT 13 /* ctt_type is base type. */
+#define CTF_K_SLICE 14 /* Variant data is a ctf_slice_t. */
+
+#define CTF_K_MAX 63 /* Maximum possible (V2) CTF_K_* value. */
+
+/* Values for ctt_type when kind is CTF_K_INTEGER. The flags, offset in bits,
+ and size in bits are encoded as a single word using the following macros.
+ (However, you can also encode the offset and bitness in a slice.) */
+
+#define CTF_INT_ENCODING(data) (((data) & 0xff000000) >> 24)
+#define CTF_INT_OFFSET(data) (((data) & 0x00ff0000) >> 16)
+#define CTF_INT_BITS(data) (((data) & 0x0000ffff))
+
+#define CTF_INT_DATA(encoding, offset, bits) \
+ (((encoding) << 24) | ((offset) << 16) | (bits))
+
+#define CTF_INT_SIGNED 0x01 /* Integer is signed (otherwise unsigned). */
+#define CTF_INT_CHAR 0x02 /* Character display format. */
+#define CTF_INT_BOOL 0x04 /* Boolean display format. */
+#define CTF_INT_VARARGS 0x08 /* Varargs display format. */
+
+/* Use CTF_CHAR to produce a char that agrees with the system's native
+ char signedness. */
+#if CHAR_MIN == 0
+# define CTF_CHAR (CTF_INT_CHAR)
+#else
+# define CTF_CHAR (CTF_INT_CHAR | CTF_INT_SIGNED)
+#endif
+
+/* Values for ctt_type when kind is CTF_K_FLOAT. The encoding, offset in bits,
+ and size in bits are encoded as a single word using the following macros.
+ (However, you can also encode the offset and bitness in a slice.) */
+
+#define CTF_FP_ENCODING(data) (((data) & 0xff000000) >> 24)
+#define CTF_FP_OFFSET(data) (((data) & 0x00ff0000) >> 16)
+#define CTF_FP_BITS(data) (((data) & 0x0000ffff))
+
+#define CTF_FP_DATA(encoding, offset, bits) \
+ (((encoding) << 24) | ((offset) << 16) | (bits))
+
+/* Variant data when kind is CTF_K_FLOAT is an encoding in the top eight bits. */
+#define CTF_FP_ENCODING(data) (((data) & 0xff000000) >> 24)
+
+#define CTF_FP_SINGLE 1 /* IEEE 32-bit float encoding. */
+#define CTF_FP_DOUBLE 2 /* IEEE 64-bit float encoding. */
+#define CTF_FP_CPLX 3 /* Complex encoding. */
+#define CTF_FP_DCPLX 4 /* Double complex encoding. */
+#define CTF_FP_LDCPLX 5 /* Long double complex encoding. */
+#define CTF_FP_LDOUBLE 6 /* Long double encoding. */
+#define CTF_FP_INTRVL 7 /* Interval (2x32-bit) encoding. */
+#define CTF_FP_DINTRVL 8 /* Double interval (2x64-bit) encoding. */
+#define CTF_FP_LDINTRVL 9 /* Long double interval (2x128-bit) encoding. */
+#define CTF_FP_IMAGRY 10 /* Imaginary (32-bit) encoding. */
+#define CTF_FP_DIMAGRY 11 /* Long imaginary (64-bit) encoding. */
+#define CTF_FP_LDIMAGRY 12 /* Long double imaginary (128-bit) encoding. */
+
+#define CTF_FP_MAX 12 /* Maximum possible CTF_FP_* value */
+
+/* A slice increases the offset and reduces the bitness of the referenced
+ ctt_type, which must be a type which has an encoding (fp, int, or enum). We
+ also store the referenced type in here, because it is easier to keep the
+ ctt_size correct for the slice than to shuffle the size into here and keep
+ the ctt_type where it is for other types. */
+
+typedef struct ctf_slice
+{
+ uint32_t cts_type;
+ unsigned char cts_offset;
+ unsigned char cts_bits;
+} ctf_slice_t;
+
+typedef struct ctf_array_v1
+{
+ unsigned short cta_contents; /* Reference to type of array contents. */
+ unsigned short cta_index; /* Reference to type of array index. */
+ uint32_t cta_nelems; /* Number of elements. */
+} ctf_array_v1_t;
+
+typedef struct ctf_array
+{
+ uint32_t cta_contents; /* Reference to type of array contents. */
+ uint32_t cta_index; /* Reference to type of array index. */
+ uint32_t cta_nelems; /* Number of elements. */
+} ctf_array_t;
+
+/* Most structure members have bit offsets that can be expressed using a short.
+ Some don't. ctf_member_t is used for structs which cannot contain any of
+ these large offsets, whereas ctf_lmember_t is used in the latter case. If
+ any member of a given struct has an offset that cannot be expressed using a
+ uint32_t, all members will be stored as type ctf_lmember_t. This is expected
+ to be very rare (but nonetheless possible). */
+
+#define CTF_LSTRUCT_THRESH 536870912
+
+/* In v1, the same is true, except that lmembers are used for structs >= 8192
+ bytes in size. (The ordering of members in the ctf_member_* structures is
+ different to improve padding.) */
+
+#define CTF_LSTRUCT_THRESH_V1 8192
+
+typedef struct ctf_member_v1
+{
+ uint32_t ctm_name; /* Reference to name in string table. */
+ unsigned short ctm_type; /* Reference to type of member. */
+ unsigned short ctm_offset; /* Offset of this member in bits. */
+} ctf_member_v1_t;
+
+typedef struct ctf_lmember_v1
+{
+ uint32_t ctlm_name; /* Reference to name in string table. */
+ unsigned short ctlm_type; /* Reference to type of member. */
+ unsigned short ctlm_pad; /* Padding. */
+ uint32_t ctlm_offsethi; /* High 32 bits of member offset in bits. */
+ uint32_t ctlm_offsetlo; /* Low 32 bits of member offset in bits. */
+} ctf_lmember_v1_t;
+
+typedef struct ctf_member_v2
+{
+ uint32_t ctm_name; /* Reference to name in string table. */
+ uint32_t ctm_offset; /* Offset of this member in bits. */
+ uint32_t ctm_type; /* Reference to type of member. */
+} ctf_member_t;
+
+typedef struct ctf_lmember_v2
+{
+ uint32_t ctlm_name; /* Reference to name in string table. */
+ uint32_t ctlm_offsethi; /* High 32 bits of member offset in bits. */
+ uint32_t ctlm_type; /* Reference to type of member. */
+ uint32_t ctlm_offsetlo; /* Low 32 bits of member offset in bits. */
+} ctf_lmember_t;
+
+#define CTF_LMEM_OFFSET(ctlmp) \
+ (((uint64_t)(ctlmp)->ctlm_offsethi) << 32 | (ctlmp)->ctlm_offsetlo)
+#define CTF_OFFSET_TO_LMEMHI(offset) ((uint32_t)((uint64_t)(offset) >> 32))
+#define CTF_OFFSET_TO_LMEMLO(offset) ((uint32_t)(offset))
+
+typedef struct ctf_enum
+{
+ uint32_t cte_name; /* Reference to name in string table. */
+ int cte_value; /* Value associated with this name. */
+} ctf_enum_t;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _CTF_H */
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