binutils-gdb/include/ctf-api.h

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/* Public API to libctf.
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/>. */
/* This header file defines the interfaces available from the CTF debugger
library, libctf. This API can be used by a debugger to operate on data in
the Compact ANSI-C Type Format (CTF). */
#ifndef _CTF_API_H
#define _CTF_API_H
#include <sys/param.h>
#include <sys/types.h>
#include <ctf.h>
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
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#include <zlib.h>
#ifdef __cplusplus
extern "C"
{
#endif
/* Clients can open one or more CTF containers and obtain a pointer to an
opaque ctf_file_t. Types are identified by an opaque ctf_id_t token.
They can also open or create read-only archives of CTF containers in a
ctf_archive_t.
These opaque definitions allow libctf to evolve without breaking clients. */
typedef struct ctf_file ctf_file_t;
typedef struct ctf_archive_internal ctf_archive_t;
libctf: fix a number of build problems found on Solaris and NetBSD - Use of nonportable <endian.h> - Use of qsort_r - Use of zlib without appropriate magic to pull in the binutils zlib - Use of off64_t without checking (fixed by dropping the unused fields that need off64_t entirely) - signedness problems due to long being too short a type on 32-bit platforms: ctf_id_t is now 'unsigned long', and CTF_ERR must be used only for functions that return ctf_id_t - One lingering use of bzero() and of <sys/errno.h> All fixed, using code from gnulib where possible. Relatedly, set cts_size in a couple of places it was missed (string table and symbol table loading upon ctf_bfdopen()). binutils/ * objdump.c (make_ctfsect): Drop cts_type, cts_flags, and cts_offset. * readelf.c (shdr_to_ctf_sect): Likewise. include/ * ctf-api.h (ctf_sect_t): Drop cts_type, cts_flags, and cts_offset. (ctf_id_t): This is now an unsigned type. (CTF_ERR): Cast it to ctf_id_t. Note that it should only be used for ctf_id_t-returning functions. libctf/ * Makefile.am (ZLIB): New. (ZLIBINC): Likewise. (AM_CFLAGS): Use them. (libctf_a_LIBADD): New, for LIBOBJS. * configure.ac: Check for zlib, endian.h, and qsort_r. * ctf-endian.h: New, providing htole64 and le64toh. * swap.h: Code style fixes. (bswap_identity_64): New. * qsort_r.c: New, from gnulib (with one added #include). * ctf-decls.h: New, providing a conditional qsort_r declaration, and unconditional definitions of MIN and MAX. * ctf-impl.h: Use it. Do not use <sys/errno.h>. (ctf_set_errno): Now returns unsigned long. * ctf-util.c (ctf_set_errno): Adjust here too. * ctf-archive.c: Use ctf-endian.h. (ctf_arc_open_by_offset): Use memset, not bzero. Drop cts_type, cts_flags and cts_offset. (ctf_arc_write): Drop debugging dependent on the size of off_t. * ctf-create.c: Provide a definition of roundup if not defined. (ctf_create): Drop cts_type, cts_flags and cts_offset. (ctf_add_reftype): Do not check if type IDs are below zero. (ctf_add_slice): Likewise. (ctf_add_typedef): Likewise. (ctf_add_member_offset): Cast error-returning ssize_t's to size_t when known error-free. Drop CTF_ERR usage for functions returning int. (ctf_add_member_encoded): Drop CTF_ERR usage for functions returning int. (ctf_add_variable): Likewise. (enumcmp): Likewise. (enumadd): Likewise. (membcmp): Likewise. (ctf_add_type): Likewise. Cast error-returning ssize_t's to size_t when known error-free. * ctf-dump.c (ctf_is_slice): Drop CTF_ERR usage for functions returning int: use CTF_ERR for functions returning ctf_type_id. (ctf_dump_label): Likewise. (ctf_dump_objts): Likewise. * ctf-labels.c (ctf_label_topmost): Likewise. (ctf_label_iter): Likewise. (ctf_label_info): Likewise. * ctf-lookup.c (ctf_func_args): Likewise. * ctf-open.c (upgrade_types): Cast to size_t where appropriate. (ctf_bufopen): Likewise. Use zlib types as needed. * ctf-types.c (ctf_member_iter): Drop CTF_ERR usage for functions returning int. (ctf_enum_iter): Likewise. (ctf_type_size): Likewise. (ctf_type_align): Likewise. Cast to size_t where appropriate. (ctf_type_kind_unsliced): Likewise. (ctf_type_kind): Likewise. (ctf_type_encoding): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_value): Likewise. (ctf_type_rvisit): Likewise. * ctf-open-bfd.c (ctf_bfdopen): Drop cts_type, cts_flags and cts_offset. (ctf_simple_open): Likewise. (ctf_bfdopen_ctfsect): Likewise. Set cts_size properly. * Makefile.in: Regenerate. * aclocal.m4: Likewise. * config.h: Likewise. * configure: Likewise.
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typedef unsigned long ctf_id_t;
/* This opaque definition allows libctf to accept BFD data structures without
importing all the BFD noise into users' namespaces. */
struct bfd;
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
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/* If the debugger needs to provide the CTF library with a set of raw buffers
for use as the CTF data, symbol table, and string table, it can do so by
filling in ctf_sect_t structures and passing them to ctf_bufopen().
The contents of this structure must always be in native endianness (no
byteswapping is performed). */
typedef struct ctf_sect
{
const char *cts_name; /* Section name (if any). */
const void *cts_data; /* Pointer to section data. */
size_t cts_size; /* Size of data in bytes. */
size_t cts_entsize; /* Size of each section entry (symtab only). */
} ctf_sect_t;
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
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/* A minimal symbol extracted from a linker's internal symbol table
representation. */
typedef struct ctf_link_sym
{
/* The st_name will not be accessed outside the call to
ctf_link_shuffle_syms(). */
const char *st_name;
uint32_t st_shndx;
uint32_t st_type;
uint32_t st_value;
} ctf_link_sym_t;
/* Indication of how to share types when linking. */
/* Share all types thare are not in conflict. The default. */
#define CTF_LINK_SHARE_UNCONFLICTED 0x0
/* Share only types that are used by multiple inputs. Not implemented yet. */
#define CTF_LINK_SHARE_DUPLICATED 0x1
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
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/* Symbolic names for CTF sections. */
typedef enum ctf_sect_names
{
CTF_SECT_HEADER,
CTF_SECT_LABEL,
CTF_SECT_OBJT,
CTF_SECT_FUNC,
CTF_SECT_VAR,
CTF_SECT_TYPE,
CTF_SECT_STR
} ctf_sect_names_t;
/* Encoding information for integers, floating-point values, and certain other
intrinsics can be obtained by calling ctf_type_encoding(), below. The flags
field will contain values appropriate for the type defined in <ctf.h>. */
typedef struct ctf_encoding
{
uint32_t cte_format; /* Data format (CTF_INT_* or CTF_FP_* flags). */
uint32_t cte_offset; /* Offset of value in bits. */
uint32_t cte_bits; /* Size of storage in bits. */
} ctf_encoding_t;
typedef struct ctf_membinfo
{
ctf_id_t ctm_type; /* Type of struct or union member. */
unsigned long ctm_offset; /* Offset of member in bits. */
} ctf_membinfo_t;
typedef struct ctf_arinfo
{
ctf_id_t ctr_contents; /* Type of array contents. */
ctf_id_t ctr_index; /* Type of array index. */
uint32_t ctr_nelems; /* Number of elements. */
} ctf_arinfo_t;
typedef struct ctf_funcinfo
{
ctf_id_t ctc_return; /* Function return type. */
uint32_t ctc_argc; /* Number of typed arguments to function. */
uint32_t ctc_flags; /* Function attributes (see below). */
} ctf_funcinfo_t;
typedef struct ctf_lblinfo
{
ctf_id_t ctb_type; /* Last type associated with the label. */
} ctf_lblinfo_t;
typedef struct ctf_snapshot_id
{
unsigned long dtd_id; /* Highest DTD ID at time of snapshot. */
unsigned long snapshot_id; /* Snapshot id at time of snapshot. */
} ctf_snapshot_id_t;
#define CTF_FUNC_VARARG 0x1 /* Function arguments end with varargs. */
libctf: fix a number of build problems found on Solaris and NetBSD - Use of nonportable <endian.h> - Use of qsort_r - Use of zlib without appropriate magic to pull in the binutils zlib - Use of off64_t without checking (fixed by dropping the unused fields that need off64_t entirely) - signedness problems due to long being too short a type on 32-bit platforms: ctf_id_t is now 'unsigned long', and CTF_ERR must be used only for functions that return ctf_id_t - One lingering use of bzero() and of <sys/errno.h> All fixed, using code from gnulib where possible. Relatedly, set cts_size in a couple of places it was missed (string table and symbol table loading upon ctf_bfdopen()). binutils/ * objdump.c (make_ctfsect): Drop cts_type, cts_flags, and cts_offset. * readelf.c (shdr_to_ctf_sect): Likewise. include/ * ctf-api.h (ctf_sect_t): Drop cts_type, cts_flags, and cts_offset. (ctf_id_t): This is now an unsigned type. (CTF_ERR): Cast it to ctf_id_t. Note that it should only be used for ctf_id_t-returning functions. libctf/ * Makefile.am (ZLIB): New. (ZLIBINC): Likewise. (AM_CFLAGS): Use them. (libctf_a_LIBADD): New, for LIBOBJS. * configure.ac: Check for zlib, endian.h, and qsort_r. * ctf-endian.h: New, providing htole64 and le64toh. * swap.h: Code style fixes. (bswap_identity_64): New. * qsort_r.c: New, from gnulib (with one added #include). * ctf-decls.h: New, providing a conditional qsort_r declaration, and unconditional definitions of MIN and MAX. * ctf-impl.h: Use it. Do not use <sys/errno.h>. (ctf_set_errno): Now returns unsigned long. * ctf-util.c (ctf_set_errno): Adjust here too. * ctf-archive.c: Use ctf-endian.h. (ctf_arc_open_by_offset): Use memset, not bzero. Drop cts_type, cts_flags and cts_offset. (ctf_arc_write): Drop debugging dependent on the size of off_t. * ctf-create.c: Provide a definition of roundup if not defined. (ctf_create): Drop cts_type, cts_flags and cts_offset. (ctf_add_reftype): Do not check if type IDs are below zero. (ctf_add_slice): Likewise. (ctf_add_typedef): Likewise. (ctf_add_member_offset): Cast error-returning ssize_t's to size_t when known error-free. Drop CTF_ERR usage for functions returning int. (ctf_add_member_encoded): Drop CTF_ERR usage for functions returning int. (ctf_add_variable): Likewise. (enumcmp): Likewise. (enumadd): Likewise. (membcmp): Likewise. (ctf_add_type): Likewise. Cast error-returning ssize_t's to size_t when known error-free. * ctf-dump.c (ctf_is_slice): Drop CTF_ERR usage for functions returning int: use CTF_ERR for functions returning ctf_type_id. (ctf_dump_label): Likewise. (ctf_dump_objts): Likewise. * ctf-labels.c (ctf_label_topmost): Likewise. (ctf_label_iter): Likewise. (ctf_label_info): Likewise. * ctf-lookup.c (ctf_func_args): Likewise. * ctf-open.c (upgrade_types): Cast to size_t where appropriate. (ctf_bufopen): Likewise. Use zlib types as needed. * ctf-types.c (ctf_member_iter): Drop CTF_ERR usage for functions returning int. (ctf_enum_iter): Likewise. (ctf_type_size): Likewise. (ctf_type_align): Likewise. Cast to size_t where appropriate. (ctf_type_kind_unsliced): Likewise. (ctf_type_kind): Likewise. (ctf_type_encoding): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_value): Likewise. (ctf_type_rvisit): Likewise. * ctf-open-bfd.c (ctf_bfdopen): Drop cts_type, cts_flags and cts_offset. (ctf_simple_open): Likewise. (ctf_bfdopen_ctfsect): Likewise. Set cts_size properly. * Makefile.in: Regenerate. * aclocal.m4: Likewise. * config.h: Likewise. * configure: Likewise.
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/* Functions that return a ctf_id_t use the following value to indicate failure.
ctf_errno() can be used to obtain an error code. Functions that return
a straight integral -1 also use ctf_errno(). */
#define CTF_ERR ((ctf_id_t) -1L)
#define ECTF_BASE 1000 /* Base value for libctf errnos. */
enum
{
ECTF_FMT = ECTF_BASE, /* File is not in CTF or ELF format. */
ECTF_BFDERR, /* BFD error. */
ECTF_CTFVERS, /* CTF version is more recent than libctf. */
ECTF_BFD_AMBIGUOUS, /* Ambiguous BFD target. */
ECTF_SYMTAB, /* Symbol table uses invalid entry size. */
ECTF_SYMBAD, /* Symbol table data buffer invalid. */
ECTF_STRBAD, /* String table data buffer invalid. */
ECTF_CORRUPT, /* File data corruption detected. */
ECTF_NOCTFDATA, /* ELF file does not contain CTF data. */
ECTF_NOCTFBUF, /* Buffer does not contain CTF data. */
ECTF_NOSYMTAB, /* Symbol table data is not available. */
ECTF_NOPARENT, /* Parent CTF container is not available. */
ECTF_DMODEL, /* Data model mismatch. */
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
2019-07-14 04:06:55 +08:00
ECTF_LINKADDEDLATE, /* File added to link too late. */
ECTF_ZALLOC, /* Failed to allocate (de)compression buffer. */
ECTF_DECOMPRESS, /* Failed to decompress CTF data. */
ECTF_STRTAB, /* String table for this string is missing. */
ECTF_BADNAME, /* String offset is corrupt w.r.t. strtab. */
ECTF_BADID, /* Invalid type ID number. */
ECTF_NOTSOU, /* Type is not a struct or union. */
ECTF_NOTENUM, /* Type is not an enum. */
ECTF_NOTSUE, /* Type is not a struct, union, or enum. */
ECTF_NOTINTFP, /* Type is not an integer, float, or enum. */
ECTF_NOTARRAY, /* Type is not an array. */
ECTF_NOTREF, /* Type does not reference another type. */
ECTF_NAMELEN, /* Buffer is too small to hold type name. */
ECTF_NOTYPE, /* No type found corresponding to name. */
ECTF_SYNTAX, /* Syntax error in type name. */
ECTF_NOTFUNC, /* Symbol entry or type is not a function. */
ECTF_NOFUNCDAT, /* No func info available for function. */
ECTF_NOTDATA, /* Symtab entry does not refer to a data obj. */
ECTF_NOTYPEDAT, /* No type info available for object. */
ECTF_NOLABEL, /* No label found corresponding to name. */
ECTF_NOLABELDATA, /* File does not contain any labels. */
ECTF_NOTSUP, /* Feature not supported. */
ECTF_NOENUMNAM, /* Enum element name not found. */
ECTF_NOMEMBNAM, /* Member name not found. */
ECTF_RDONLY, /* CTF container is read-only. */
ECTF_DTFULL, /* CTF type is full (no more members allowed). */
ECTF_FULL, /* CTF container is full. */
ECTF_DUPLICATE, /* Duplicate member or variable name. */
ECTF_CONFLICT, /* Conflicting type definition present. */
ECTF_OVERROLLBACK, /* Attempt to roll back past a ctf_update. */
ECTF_COMPRESS, /* Failed to compress CTF data. */
ECTF_ARCREATE, /* Error creating CTF archive. */
ECTF_ARNNAME, /* Name not found in CTF archive. */
ECTF_SLICEOVERFLOW, /* Overflow of type bitness or offset in slice. */
ECTF_DUMPSECTUNKNOWN, /* Unknown section number in dump. */
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
2019-07-14 04:06:55 +08:00
ECTF_DUMPSECTCHANGED, /* Section changed in middle of dump. */
ECTF_NOTYET, /* Feature not yet implemented. */
ECTF_INTERNAL /* Internal error in link. */
};
/* The CTF data model is inferred to be the caller's data model or the data
model of the given object, unless ctf_setmodel() is explicitly called. */
#define CTF_MODEL_ILP32 1 /* Object data model is ILP32. */
#define CTF_MODEL_LP64 2 /* Object data model is LP64. */
#ifdef _LP64
# define CTF_MODEL_NATIVE CTF_MODEL_LP64
#else
# define CTF_MODEL_NATIVE CTF_MODEL_ILP32
#endif
/* Dynamic CTF containers can be created using ctf_create(). The ctf_add_*
routines can be used to add new definitions to the dynamic container.
New types are labeled as root or non-root to determine whether they are
visible at the top-level program scope when subsequently doing a lookup. */
#define CTF_ADD_NONROOT 0 /* Type only visible in nested scope. */
#define CTF_ADD_ROOT 1 /* Type visible at top-level scope. */
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
/* These typedefs are used to define the signature for callback functions
that can be used with the iteration and visit functions below. */
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
2019-04-24 18:03:37 +08:00
typedef int ctf_visit_f (const char *name, ctf_id_t type, unsigned long offset,
int depth, void *arg);
typedef int ctf_member_f (const char *name, ctf_id_t membtype,
unsigned long offset, void *arg);
typedef int ctf_enum_f (const char *name, int val, void *arg);
typedef int ctf_variable_f (const char *name, ctf_id_t type, void *arg);
typedef int ctf_type_f (ctf_id_t type, void *arg);
typedef int ctf_type_all_f (ctf_id_t type, int flag, void *arg);
typedef int ctf_label_f (const char *name, const ctf_lblinfo_t *info,
void *arg);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
typedef int ctf_archive_member_f (ctf_file_t *fp, const char *name, void *arg);
typedef int ctf_archive_raw_member_f (const char *name, const void *content,
size_t len, void *arg);
typedef char *ctf_dump_decorate_f (ctf_sect_names_t sect,
char *line, void *arg);
typedef struct ctf_dump_state ctf_dump_state_t;
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
/* Opening. These mostly return an abstraction over both CTF files and CTF
archives: so they can be used to open both. CTF files will appear to be an
archive with one member named '.ctf'. The low-level functions
ctf_simple_open() and ctf_bufopen() return ctf_file_t's directly, and cannot
be used on CTF archives. */
extern ctf_archive_t *ctf_bfdopen (struct bfd *, int *);
extern ctf_archive_t *ctf_bfdopen_ctfsect (struct bfd *, const ctf_sect_t *,
int *);
extern ctf_archive_t *ctf_fdopen (int fd, const char *filename,
const char *target, int *errp);
extern ctf_archive_t *ctf_open (const char *filename,
const char *target, int *errp);
extern void ctf_close (ctf_archive_t *);
libctf: opening This fills in the other half of the opening/creation puzzle: opening of already-existing CTF files. Such files are always read-only: if you want to add to a CTF file opened with one of the opening functions in this file, use ctf_add_type(), in a later commit, to copy appropriate types into a newly ctf_create()d, writable container. The lowest-level opening functions are in here: ctf_bufopen(), which takes ctf_sect_t structures akin to ELF section headers, and ctf_simple_open(), which can be used if you don't have an entire ELF section header to work from. Both will malloc() new space for the buffers only if necessary, will mmap() directly from the file if requested, and will mprotect() it afterwards to prevent accidental corruption of the types. These functions are also used by ctf_update() when converting types in a writable container into read-only types that can be looked up using the lookup functions (in later commits). The files are always of the native endianness of the system that created them: at read time, the endianness of the header magic number is used to determine whether or not the file needs byte-swapping, and the entire thing is aggressively byte-swapped. The agggressive nature of this swapping avoids complicating the rest of the code with endianness conversions, while the native endianness introduces no byte-swapping overhead in the common case. (The endianness-independence code is also much newer than everything else in this file, and deserves closer scrutiny.) The accessors at the top of the file are there to transparently support older versions of the CTF file format, allowing translation from older formats that have different sizes for the structures in ctf.h: currently, these older formats are intermingled with the newer ones in ctf.h: they will probably migrate to a compatibility header in time, to ease readability. The ctf_set_base() function is split out for the same reason: when conversion code to a newer format is written, it would need to malloc() new storage for the entire ctf_file_t if a file format change causes it to grow, and for that we need ctf_set_base() to be a separate function. One pair of linked data structures supported by this file has no creation code in libctf yet: the data and function object sections read by init_symtab(). These will probably arrive soon, when the linker comes to need them. (init_symtab() has hardly been changed since 2009, but if any code in libctf has rotted over time, this will.) A few simple accessors are also present that can even be called on read-only containers because they don't actually modify them, since the relevant things are not stored in the container but merely change its operation: ctf_setmodel(), which lets you specify whether a container is LP64 or not (used to statically determine the sizes of a few types), ctf_import(), which is the only way to associate a parent container with a child container, and ctf_setspecific(), which lets the caller associate an arbitrary pointer with the CTF container for any use. If the user doesn't call these functions correctly, libctf will misbehave: this is particularly important for ctf_import(), since a container built against a given parent container will not be able to resolve types that depend on types in the parent unless it is ctf_import()ed with a parent container with the same set of types at the same IDs, or a superset. Possible future extensions (also noted in the ctf-hash.c file) include storing a count of things so that we don't need to do one pass over the CTF file counting everything, and computing a perfect hash at CTF creation time in some compact form, storing it in the CTF file, and using it to hash things so we don't need to do a second pass over the entire CTF file to set up the hashes used to go from names to type IDs. (There are multiple such hashes, one for each C type namespace: types, enums, structs, and unions.) libctf/ * ctf-open.c: New file. * swap.h: Likewise. include/ * ctf-api.h (ctf_file_close): New declaration. (ctf_getdatasect): Likewise. (ctf_parent_file): Likewise. (ctf_parent_name): Likewise. (ctf_parent_name_set): Likewise. (ctf_import): Likewise. (ctf_setmodel): Likewise. (ctf_getmodel): Likewise. (ctf_setspecific): Likewise. (ctf_getspecific): Likewise.
2019-04-24 17:17:13 +08:00
extern ctf_sect_t ctf_getdatasect (const ctf_file_t *);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
extern ctf_archive_t *ctf_get_arc (const ctf_file_t *);
extern ctf_archive_t *ctf_arc_open (const char *, int *);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
extern void ctf_arc_close (ctf_archive_t *);
extern ctf_file_t *ctf_arc_open_by_name (const ctf_archive_t *,
const char *, int *);
extern ctf_file_t *ctf_arc_open_by_name_sections (const ctf_archive_t *,
const ctf_sect_t *,
const ctf_sect_t *,
const char *, int *);
/* The next functions return or close real CTF files, or write out CTF archives,
not opaque containers around either. */
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
2019-04-24 05:45:46 +08:00
extern ctf_file_t *ctf_simple_open (const char *, size_t, const char *, size_t,
size_t, const char *, size_t, int *);
extern ctf_file_t *ctf_bufopen (const ctf_sect_t *, const ctf_sect_t *,
const ctf_sect_t *, int *);
libctf: opening This fills in the other half of the opening/creation puzzle: opening of already-existing CTF files. Such files are always read-only: if you want to add to a CTF file opened with one of the opening functions in this file, use ctf_add_type(), in a later commit, to copy appropriate types into a newly ctf_create()d, writable container. The lowest-level opening functions are in here: ctf_bufopen(), which takes ctf_sect_t structures akin to ELF section headers, and ctf_simple_open(), which can be used if you don't have an entire ELF section header to work from. Both will malloc() new space for the buffers only if necessary, will mmap() directly from the file if requested, and will mprotect() it afterwards to prevent accidental corruption of the types. These functions are also used by ctf_update() when converting types in a writable container into read-only types that can be looked up using the lookup functions (in later commits). The files are always of the native endianness of the system that created them: at read time, the endianness of the header magic number is used to determine whether or not the file needs byte-swapping, and the entire thing is aggressively byte-swapped. The agggressive nature of this swapping avoids complicating the rest of the code with endianness conversions, while the native endianness introduces no byte-swapping overhead in the common case. (The endianness-independence code is also much newer than everything else in this file, and deserves closer scrutiny.) The accessors at the top of the file are there to transparently support older versions of the CTF file format, allowing translation from older formats that have different sizes for the structures in ctf.h: currently, these older formats are intermingled with the newer ones in ctf.h: they will probably migrate to a compatibility header in time, to ease readability. The ctf_set_base() function is split out for the same reason: when conversion code to a newer format is written, it would need to malloc() new storage for the entire ctf_file_t if a file format change causes it to grow, and for that we need ctf_set_base() to be a separate function. One pair of linked data structures supported by this file has no creation code in libctf yet: the data and function object sections read by init_symtab(). These will probably arrive soon, when the linker comes to need them. (init_symtab() has hardly been changed since 2009, but if any code in libctf has rotted over time, this will.) A few simple accessors are also present that can even be called on read-only containers because they don't actually modify them, since the relevant things are not stored in the container but merely change its operation: ctf_setmodel(), which lets you specify whether a container is LP64 or not (used to statically determine the sizes of a few types), ctf_import(), which is the only way to associate a parent container with a child container, and ctf_setspecific(), which lets the caller associate an arbitrary pointer with the CTF container for any use. If the user doesn't call these functions correctly, libctf will misbehave: this is particularly important for ctf_import(), since a container built against a given parent container will not be able to resolve types that depend on types in the parent unless it is ctf_import()ed with a parent container with the same set of types at the same IDs, or a superset. Possible future extensions (also noted in the ctf-hash.c file) include storing a count of things so that we don't need to do one pass over the CTF file counting everything, and computing a perfect hash at CTF creation time in some compact form, storing it in the CTF file, and using it to hash things so we don't need to do a second pass over the entire CTF file to set up the hashes used to go from names to type IDs. (There are multiple such hashes, one for each C type namespace: types, enums, structs, and unions.) libctf/ * ctf-open.c: New file. * swap.h: Likewise. include/ * ctf-api.h (ctf_file_close): New declaration. (ctf_getdatasect): Likewise. (ctf_parent_file): Likewise. (ctf_parent_name): Likewise. (ctf_parent_name_set): Likewise. (ctf_import): Likewise. (ctf_setmodel): Likewise. (ctf_getmodel): Likewise. (ctf_setspecific): Likewise. (ctf_getspecific): Likewise.
2019-04-24 17:17:13 +08:00
extern void ctf_file_close (ctf_file_t *);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
extern int ctf_arc_write (const char *, ctf_file_t **, size_t,
const char **, size_t);
extern int ctf_arc_write_fd (int, ctf_file_t **, size_t, const char **,
size_t);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
2019-04-24 18:30:17 +08:00
libctf: allow the header to change between versions libctf supports dynamic upgrading of the type table as file format versions change, but before now has not supported changes to the CTF header. Doing this is complicated by the baroque storage method used: the CTF header is kept prepended to the rest of the CTF data, just as when read from the file, and written out from there, and is endian-flipped in place. This makes accessing it needlessly hard and makes it almost impossible to make the header larger if we add fields. The general storage machinery around the malloced ctf pointer (the 'ctf_base') is also overcomplicated: the pointer is sometimes malloced locally and sometimes assigned from a parameter, so freeing it requires checking to see if that parameter was used, needlessly coupling ctf_bufopen and ctf_file_close together. So split the header out into a new ctf_file_t.ctf_header, which is written out explicitly: squeeze it out of the CTF buffer whenever we reallocate it, and use ctf_file_t.ctf_buf to skip past the header when we do not need to reallocate (when no upgrading or endian-flipping is required). We now track whether the CTF base can be freed explicitly via a new ctf_dynbase pointer which is non-NULL only when freeing is possible. With all this done, we can upgrade the header on the fly and add new fields as desired, via a new upgrade_header function in ctf-open. As with other forms of upgrading, libctf upgrades older headers automatically to the latest supported version at open time. For a first use of this field, we add a new string field cth_cuname, and a corresponding setter/getter pair ctf_cuname_set and ctf_cuname: this is used by debuggers to determine whether a CTF section's types relate to a single compilation unit, or to all compilation units in the program. (Types with ambiguous definitions in different CUs have only one of these types placed in the top-level shared .ctf container: the rest are placed in much smaller per-CU containers, which have the shared container as their parent. Since CTF must be useful in the absence of DWARF, we store the names of the relevant CUs ourselves, so the debugger can look them up.) v5: fix tabdamage. include/ * ctf-api.h (ctf_cuname): New function. (ctf_cuname_set): Likewise. * ctf.h: Improve comment around upgrading, no longer implying that v2 is the target of upgrades (it is v3 now). (ctf_header_v2_t): New, old-format header for backward compatibility. (ctf_header_t): Add cth_cuname: this is the first of several header changes in format v3. libctf/ * ctf-impl.h (ctf_file_t): New fields ctf_header, ctf_dynbase, ctf_cuname, ctf_dyncuname: ctf_base and ctf_buf are no longer const. * ctf-open.c (ctf_set_base): Preserve the gap between ctf_buf and ctf_base: do not assume that it is always sizeof (ctf_header_t). Print out ctf_cuname: only print out ctf_parname if set. (ctf_free_base): Removed, ctf_base is no longer freed: free ctf_dynbase instead. (ctf_set_version): Fix spacing. (upgrade_header): New, in-place header upgrading. (upgrade_types): Rename to... (upgrade_types_v1): ... this. Free ctf_dynbase, not ctf_base. No longer track old and new headers separately. No longer allow for header sizes explicitly: squeeze the headers out on upgrade (they are preserved in fp->ctf_header). Set ctf_dynbase, ctf_base and ctf_buf explicitly. Use ctf_free, not ctf_free_base. (upgrade_types): New, also handle ctf_parmax updating. (flip_header): Flip ctf_cuname. (flip_types): Flip BUF explicitly rather than deriving BUF from BASE. (ctf_bufopen): Store the header in fp->ctf_header. Correct minimum required alignment of objtoff and funcoff. No longer store it in the ctf_buf unless that buf is derived unmodified from the input. Set ctf_dynbase where ctf_base is dynamically allocated. Drop locals that duplicate fields in ctf_file: move allocation of ctf_file further up instead. Call upgrade_header as needed. Move version-specific ctf_parmax initialization into upgrade_types. More concise error handling. (ctf_file_close): No longer test for null pointers before freeing. Free ctf_dyncuname, ctf_dynbase, and ctf_header. Do not call ctf_free_base. (ctf_cuname): New. (ctf_cuname_set): New. * ctf-create.c (ctf_update): Populate ctf_cuname. (ctf_gzwrite): Write out the header explicitly. Remove obsolescent comment. (ctf_write): Likewise. (ctf_compress_write): Get the header from ctf_header, not ctf_base. Fix the compression length: fp->ctf_size never counted the CTF header. Simplify the compress call accordingly.
2019-07-07 00:36:21 +08:00
extern const char *ctf_cuname (ctf_file_t *);
extern void ctf_cuname_set (ctf_file_t *, const char *);
libctf: opening This fills in the other half of the opening/creation puzzle: opening of already-existing CTF files. Such files are always read-only: if you want to add to a CTF file opened with one of the opening functions in this file, use ctf_add_type(), in a later commit, to copy appropriate types into a newly ctf_create()d, writable container. The lowest-level opening functions are in here: ctf_bufopen(), which takes ctf_sect_t structures akin to ELF section headers, and ctf_simple_open(), which can be used if you don't have an entire ELF section header to work from. Both will malloc() new space for the buffers only if necessary, will mmap() directly from the file if requested, and will mprotect() it afterwards to prevent accidental corruption of the types. These functions are also used by ctf_update() when converting types in a writable container into read-only types that can be looked up using the lookup functions (in later commits). The files are always of the native endianness of the system that created them: at read time, the endianness of the header magic number is used to determine whether or not the file needs byte-swapping, and the entire thing is aggressively byte-swapped. The agggressive nature of this swapping avoids complicating the rest of the code with endianness conversions, while the native endianness introduces no byte-swapping overhead in the common case. (The endianness-independence code is also much newer than everything else in this file, and deserves closer scrutiny.) The accessors at the top of the file are there to transparently support older versions of the CTF file format, allowing translation from older formats that have different sizes for the structures in ctf.h: currently, these older formats are intermingled with the newer ones in ctf.h: they will probably migrate to a compatibility header in time, to ease readability. The ctf_set_base() function is split out for the same reason: when conversion code to a newer format is written, it would need to malloc() new storage for the entire ctf_file_t if a file format change causes it to grow, and for that we need ctf_set_base() to be a separate function. One pair of linked data structures supported by this file has no creation code in libctf yet: the data and function object sections read by init_symtab(). These will probably arrive soon, when the linker comes to need them. (init_symtab() has hardly been changed since 2009, but if any code in libctf has rotted over time, this will.) A few simple accessors are also present that can even be called on read-only containers because they don't actually modify them, since the relevant things are not stored in the container but merely change its operation: ctf_setmodel(), which lets you specify whether a container is LP64 or not (used to statically determine the sizes of a few types), ctf_import(), which is the only way to associate a parent container with a child container, and ctf_setspecific(), which lets the caller associate an arbitrary pointer with the CTF container for any use. If the user doesn't call these functions correctly, libctf will misbehave: this is particularly important for ctf_import(), since a container built against a given parent container will not be able to resolve types that depend on types in the parent unless it is ctf_import()ed with a parent container with the same set of types at the same IDs, or a superset. Possible future extensions (also noted in the ctf-hash.c file) include storing a count of things so that we don't need to do one pass over the CTF file counting everything, and computing a perfect hash at CTF creation time in some compact form, storing it in the CTF file, and using it to hash things so we don't need to do a second pass over the entire CTF file to set up the hashes used to go from names to type IDs. (There are multiple such hashes, one for each C type namespace: types, enums, structs, and unions.) libctf/ * ctf-open.c: New file. * swap.h: Likewise. include/ * ctf-api.h (ctf_file_close): New declaration. (ctf_getdatasect): Likewise. (ctf_parent_file): Likewise. (ctf_parent_name): Likewise. (ctf_parent_name_set): Likewise. (ctf_import): Likewise. (ctf_setmodel): Likewise. (ctf_getmodel): Likewise. (ctf_setspecific): Likewise. (ctf_getspecific): Likewise.
2019-04-24 17:17:13 +08:00
extern ctf_file_t *ctf_parent_file (ctf_file_t *);
extern const char *ctf_parent_name (ctf_file_t *);
extern void ctf_parent_name_set (ctf_file_t *, const char *);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
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extern int ctf_type_isparent (ctf_file_t *, ctf_id_t);
extern int ctf_type_ischild (ctf_file_t *, ctf_id_t);
libctf: opening This fills in the other half of the opening/creation puzzle: opening of already-existing CTF files. Such files are always read-only: if you want to add to a CTF file opened with one of the opening functions in this file, use ctf_add_type(), in a later commit, to copy appropriate types into a newly ctf_create()d, writable container. The lowest-level opening functions are in here: ctf_bufopen(), which takes ctf_sect_t structures akin to ELF section headers, and ctf_simple_open(), which can be used if you don't have an entire ELF section header to work from. Both will malloc() new space for the buffers only if necessary, will mmap() directly from the file if requested, and will mprotect() it afterwards to prevent accidental corruption of the types. These functions are also used by ctf_update() when converting types in a writable container into read-only types that can be looked up using the lookup functions (in later commits). The files are always of the native endianness of the system that created them: at read time, the endianness of the header magic number is used to determine whether or not the file needs byte-swapping, and the entire thing is aggressively byte-swapped. The agggressive nature of this swapping avoids complicating the rest of the code with endianness conversions, while the native endianness introduces no byte-swapping overhead in the common case. (The endianness-independence code is also much newer than everything else in this file, and deserves closer scrutiny.) The accessors at the top of the file are there to transparently support older versions of the CTF file format, allowing translation from older formats that have different sizes for the structures in ctf.h: currently, these older formats are intermingled with the newer ones in ctf.h: they will probably migrate to a compatibility header in time, to ease readability. The ctf_set_base() function is split out for the same reason: when conversion code to a newer format is written, it would need to malloc() new storage for the entire ctf_file_t if a file format change causes it to grow, and for that we need ctf_set_base() to be a separate function. One pair of linked data structures supported by this file has no creation code in libctf yet: the data and function object sections read by init_symtab(). These will probably arrive soon, when the linker comes to need them. (init_symtab() has hardly been changed since 2009, but if any code in libctf has rotted over time, this will.) A few simple accessors are also present that can even be called on read-only containers because they don't actually modify them, since the relevant things are not stored in the container but merely change its operation: ctf_setmodel(), which lets you specify whether a container is LP64 or not (used to statically determine the sizes of a few types), ctf_import(), which is the only way to associate a parent container with a child container, and ctf_setspecific(), which lets the caller associate an arbitrary pointer with the CTF container for any use. If the user doesn't call these functions correctly, libctf will misbehave: this is particularly important for ctf_import(), since a container built against a given parent container will not be able to resolve types that depend on types in the parent unless it is ctf_import()ed with a parent container with the same set of types at the same IDs, or a superset. Possible future extensions (also noted in the ctf-hash.c file) include storing a count of things so that we don't need to do one pass over the CTF file counting everything, and computing a perfect hash at CTF creation time in some compact form, storing it in the CTF file, and using it to hash things so we don't need to do a second pass over the entire CTF file to set up the hashes used to go from names to type IDs. (There are multiple such hashes, one for each C type namespace: types, enums, structs, and unions.) libctf/ * ctf-open.c: New file. * swap.h: Likewise. include/ * ctf-api.h (ctf_file_close): New declaration. (ctf_getdatasect): Likewise. (ctf_parent_file): Likewise. (ctf_parent_name): Likewise. (ctf_parent_name_set): Likewise. (ctf_import): Likewise. (ctf_setmodel): Likewise. (ctf_getmodel): Likewise. (ctf_setspecific): Likewise. (ctf_getspecific): Likewise.
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extern int ctf_import (ctf_file_t *, ctf_file_t *);
extern int ctf_setmodel (ctf_file_t *, int);
extern int ctf_getmodel (ctf_file_t *);
extern void ctf_setspecific (ctf_file_t *, void *);
extern void *ctf_getspecific (ctf_file_t *);
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
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extern int ctf_errno (ctf_file_t *);
extern const char *ctf_errmsg (int);
extern int ctf_version (int);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
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extern int ctf_func_info (ctf_file_t *, unsigned long, ctf_funcinfo_t *);
extern int ctf_func_args (ctf_file_t *, unsigned long, uint32_t, ctf_id_t *);
extern int ctf_func_type_info (ctf_file_t *, ctf_id_t, ctf_funcinfo_t *);
extern int ctf_func_type_args (ctf_file_t *, ctf_id_t, uint32_t, ctf_id_t *);
extern ctf_id_t ctf_lookup_by_name (ctf_file_t *, const char *);
extern ctf_id_t ctf_lookup_by_symbol (ctf_file_t *, unsigned long);
extern ctf_id_t ctf_lookup_variable (ctf_file_t *, const char *);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
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extern ctf_id_t ctf_type_resolve (ctf_file_t *, ctf_id_t);
extern char *ctf_type_aname (ctf_file_t *, ctf_id_t);
extern char *ctf_type_aname_raw (ctf_file_t *, ctf_id_t);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
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extern ssize_t ctf_type_lname (ctf_file_t *, ctf_id_t, char *, size_t);
extern char *ctf_type_name (ctf_file_t *, ctf_id_t, char *, size_t);
extern ssize_t ctf_type_size (ctf_file_t *, ctf_id_t);
extern ssize_t ctf_type_align (ctf_file_t *, ctf_id_t);
extern int ctf_type_kind (ctf_file_t *, ctf_id_t);
extern ctf_id_t ctf_type_reference (ctf_file_t *, ctf_id_t);
extern ctf_id_t ctf_type_pointer (ctf_file_t *, ctf_id_t);
extern int ctf_type_encoding (ctf_file_t *, ctf_id_t, ctf_encoding_t *);
extern int ctf_type_visit (ctf_file_t *, ctf_id_t, ctf_visit_f *, void *);
extern int ctf_type_cmp (ctf_file_t *, ctf_id_t, ctf_file_t *, ctf_id_t);
extern int ctf_type_compat (ctf_file_t *, ctf_id_t, ctf_file_t *, ctf_id_t);
extern int ctf_member_info (ctf_file_t *, ctf_id_t, const char *,
ctf_membinfo_t *);
extern int ctf_array_info (ctf_file_t *, ctf_id_t, ctf_arinfo_t *);
extern const char *ctf_enum_name (ctf_file_t *, ctf_id_t, int);
extern int ctf_enum_value (ctf_file_t *, ctf_id_t, const char *, int *);
extern void ctf_label_set (ctf_file_t *, const char *);
extern const char *ctf_label_get (ctf_file_t *);
extern const char *ctf_label_topmost (ctf_file_t *);
extern int ctf_label_info (ctf_file_t *, const char *, ctf_lblinfo_t *);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
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extern int ctf_member_iter (ctf_file_t *, ctf_id_t, ctf_member_f *, void *);
extern int ctf_enum_iter (ctf_file_t *, ctf_id_t, ctf_enum_f *, void *);
extern int ctf_type_iter (ctf_file_t *, ctf_type_f *, void *);
extern int ctf_type_iter_all (ctf_file_t *, ctf_type_all_f *, void *);
extern int ctf_label_iter (ctf_file_t *, ctf_label_f *, void *);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
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extern int ctf_variable_iter (ctf_file_t *, ctf_variable_f *, void *);
libctf: mmappable archives If you need to store a large number of CTF containers somewhere, this provides a dedicated facility for doing so: an mmappable archive format like a very simple tar or ar without all the system-dependent format horrors or need for heavy file copying, with built-in compression of files above a particular size threshold. libctf automatically mmap()s uncompressed elements of these archives, or uncompresses them, as needed. (If the platform does not support mmap(), copying into dynamically-allocated buffers is used.) Archive iteration operations are partitioned into raw and non-raw forms. Raw operations pass thhe raw archive contents to the callback: non-raw forms open each member with ctf_bufopen() and pass the resulting ctf_file_t to the iterator instead. This lets you manipulate the raw data in the archive, or the contents interpreted as a CTF file, as needed. It is not yet known whether we will store CTF archives in a linked ELF object in one of these (akin to debugdata) or whether they'll get one section per TU plus one parent container for types shared between them. (In the case of ELF objects with very large numbers of TUs, an archive of all of them would seem preferable, so we might just use an archive, and add lzma support so you can assume that .gnu_debugdata and .ctf are compressed using the same algorithm if both are present.) To make usage easier, the ctf_archive_t is not the on-disk representation but an abstraction over both ctf_file_t's and archives of many ctf_file_t's: users see both CTF archives and raw CTF files as ctf_archive_t's upon opening, the only difference being that a raw CTF file has only a single "archive member", named ".ctf" (the default if a null pointer is passed in as the name). The next commit will make use of this facility, in addition to providing the public interface to actually open archives. (In the future, it should be possible to have all CTF sections in an ELF file appear as an "archive" in the same fashion.) This machinery is also used to allow library-internal creators of ctf_archive_t's (such as the next commit) to stash away an ELF string and symbol table, so that all opens of members in a given archive will use them. This lets CTF archives exploit the ELF string and symbol table just like raw CTF files can. (All this leads to somewhat confusing type naming. The ctf_archive_t is a typedef for the opaque internal type, struct ctf_archive_internal: the non-internal "struct ctf_archive" is the on-disk structure meant for other libraries manipulating CTF files. It is probably clearest to use the struct name for struct ctf_archive_internal inside the program, and the typedef names outside.) libctf/ * ctf-archive.c: New. * ctf-impl.h (ctf_archive_internal): New type. (ctf_arc_open_internal): New declaration. (ctf_arc_bufopen): Likewise. (ctf_arc_close_internal): Likewise. include/ * ctf.h (CTFA_MAGIC): New. (struct ctf_archive): New. (struct ctf_archive_modent): Likewise. * ctf-api.h (ctf_archive_member_f): New. (ctf_archive_raw_member_f): Likewise. (ctf_arc_write): Likewise. (ctf_arc_close): Likewise. (ctf_arc_open_by_name): Likewise. (ctf_archive_iter): Likewise. (ctf_archive_raw_iter): Likewise. (ctf_get_arc): Likewise.
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extern int ctf_archive_iter (const ctf_archive_t *, ctf_archive_member_f *,
void *);
/* This function alone does not currently operate on CTF files masquerading
as archives, and returns -EINVAL: the raw data is no longer available. It is
expected to be used only by archiving tools, in any case, which have no need
to deal with non-archives at all. */
extern int ctf_archive_raw_iter (const ctf_archive_t *,
ctf_archive_raw_member_f *, void *);
extern char *ctf_dump (ctf_file_t *, ctf_dump_state_t **state,
ctf_sect_names_t sect, ctf_dump_decorate_f *,
void *arg);
libctf: core type lookup Finally we get to the functions used to actually look up and enumerate properties of types in a container (names, sizes, members, what type a pointer or cv-qual references, determination of whether two types are assignment-compatible, etc). With a very few exceptions these do not work for types newly added via ctf_add_*(): they only work on types in read-only containers, or types added before the most recent call to ctf_update(). This also adds support for lookup of "variables" (string -> type ID mappings) and for generation of C type names corresponding to a type ID. libctf/ * ctf-decl.c: New file. * ctf-types.c: Likewise. * ctf-impl.h: New declarations. include/ * ctf-api.h (ctf_visit_f): New definition. (ctf_member_f): Likewise. (ctf_enum_f): Likewise. (ctf_variable_f): Likewise. (ctf_type_f): Likewise. (ctf_type_isparent): Likewise. (ctf_type_ischild): Likewise. (ctf_type_resolve): Likewise. (ctf_type_aname): Likewise. (ctf_type_lname): Likewise. (ctf_type_name): Likewise. (ctf_type_sizee): Likewise. (ctf_type_align): Likewise. (ctf_type_kind): Likewise. (ctf_type_reference): Likewise. (ctf_type_pointer): Likewise. (ctf_type_encoding): Likewise. (ctf_type_visit): Likewise. (ctf_type_cmp): Likewise. (ctf_type_compat): Likewise. (ctf_member_info): Likewise. (ctf_array_info): Likewise. (ctf_enum_name): Likewise. (ctf_enum_value): Likewise. (ctf_member_iter): Likewise. (ctf_enum_iter): Likewise. (ctf_type_iter): Likewise. (ctf_variable_iter): Likewise.
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libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
2019-04-24 05:45:46 +08:00
extern ctf_id_t ctf_add_array (ctf_file_t *, uint32_t,
const ctf_arinfo_t *);
extern ctf_id_t ctf_add_const (ctf_file_t *, uint32_t, ctf_id_t);
extern ctf_id_t ctf_add_enum_encoded (ctf_file_t *, uint32_t, const char *,
const ctf_encoding_t *);
extern ctf_id_t ctf_add_enum (ctf_file_t *, uint32_t, const char *);
extern ctf_id_t ctf_add_float (ctf_file_t *, uint32_t,
const char *, const ctf_encoding_t *);
extern ctf_id_t ctf_add_forward (ctf_file_t *, uint32_t, const char *,
uint32_t);
extern ctf_id_t ctf_add_function (ctf_file_t *, uint32_t,
const ctf_funcinfo_t *, const ctf_id_t *);
extern ctf_id_t ctf_add_integer (ctf_file_t *, uint32_t, const char *,
const ctf_encoding_t *);
extern ctf_id_t ctf_add_slice (ctf_file_t *, uint32_t, ctf_id_t, const ctf_encoding_t *);
extern ctf_id_t ctf_add_pointer (ctf_file_t *, uint32_t, ctf_id_t);
extern ctf_id_t ctf_add_type (ctf_file_t *, ctf_file_t *, ctf_id_t);
extern ctf_id_t ctf_add_typedef (ctf_file_t *, uint32_t, const char *,
ctf_id_t);
extern ctf_id_t ctf_add_restrict (ctf_file_t *, uint32_t, ctf_id_t);
extern ctf_id_t ctf_add_struct (ctf_file_t *, uint32_t, const char *);
extern ctf_id_t ctf_add_union (ctf_file_t *, uint32_t, const char *);
extern ctf_id_t ctf_add_struct_sized (ctf_file_t *, uint32_t, const char *,
size_t);
extern ctf_id_t ctf_add_union_sized (ctf_file_t *, uint32_t, const char *,
size_t);
extern ctf_id_t ctf_add_volatile (ctf_file_t *, uint32_t, ctf_id_t);
extern int ctf_add_enumerator (ctf_file_t *, ctf_id_t, const char *, int);
extern int ctf_add_member (ctf_file_t *, ctf_id_t, const char *, ctf_id_t);
extern int ctf_add_member_offset (ctf_file_t *, ctf_id_t, const char *,
ctf_id_t, unsigned long);
extern int ctf_add_member_encoded (ctf_file_t *, ctf_id_t, const char *,
ctf_id_t, unsigned long,
const ctf_encoding_t);
extern int ctf_add_variable (ctf_file_t *, const char *, ctf_id_t);
extern int ctf_set_array (ctf_file_t *, ctf_id_t, const ctf_arinfo_t *);
extern ctf_file_t *ctf_create (int *);
extern int ctf_update (ctf_file_t *);
extern ctf_snapshot_id_t ctf_snapshot (ctf_file_t *);
extern int ctf_rollback (ctf_file_t *, ctf_snapshot_id_t);
extern int ctf_discard (ctf_file_t *);
extern int ctf_write (ctf_file_t *, int);
extern int ctf_gzwrite (ctf_file_t *fp, gzFile fd);
libctf: creation functions The CTF creation process looks roughly like (error handling elided): int err; ctf_file_t *foo = ctf_create (&err); ctf_id_t type = ctf_add_THING (foo, ...); ctf_update (foo); ctf_*write (...); Some ctf_add_THING functions accept other type IDs as arguments, depending on the type: cv-quals, pointers, and structure and union members all take other types as arguments. So do 'slices', which let you take an existing integral type and recast it as a type with a different bitness or offset within a byte, for bitfields. One class of THING is not a type: "variables", which are mappings of names (in the internal string table) to types. These are mostly useful when encoding variables that do not appear in a symbol table but which some external user has some other way to figure out the address of at runtime (dynamic symbol lookup or querying a VM interpreter or something). You can snapshot the creation process at any point: rolling back to a snapshot deletes all types and variables added since that point. You can make arbitrary type queries on the CTF container during the creation process, but you must call ctf_update() first, which translates the growing dynamic container into a static one (this uses the CTF opening machinery, added in a later commit), which is quite expensive. This function must also be called after adding types and before writing the container out. Because addition of types involves looking up existing types, we add a little of the type lookup machinery here, as well: only enough to look up types in dynamic containers under construction. libctf/ * ctf-create.c: New file. * ctf-lookup.c: New file. include/ * ctf-api.h (zlib.h): New include. (ctf_sect_t): New. (ctf_sect_names_t): Likewise. (ctf_encoding_t): Likewise. (ctf_membinfo_t): Likewise. (ctf_arinfo_t): Likewise. (ctf_funcinfo_t): Likewise. (ctf_lblinfo_t): Likewise. (ctf_snapshot_id_t): Likewise. (CTF_FUNC_VARARG): Likewise. (ctf_simple_open): Likewise. (ctf_bufopen): Likewise. (ctf_create): Likewise. (ctf_add_array): Likewise. (ctf_add_const): Likewise. (ctf_add_enum_encoded): Likewise. (ctf_add_enum): Likewise. (ctf_add_float): Likewise. (ctf_add_forward): Likewise. (ctf_add_function): Likewise. (ctf_add_integer): Likewise. (ctf_add_slice): Likewise. (ctf_add_pointer): Likewise. (ctf_add_type): Likewise. (ctf_add_typedef): Likewise. (ctf_add_restrict): Likewise. (ctf_add_struct): Likewise. (ctf_add_union): Likewise. (ctf_add_struct_sized): Likewise. (ctf_add_union_sized): Likewise. (ctf_add_volatile): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_member_encoded): Likewise. (ctf_add_variable): Likewise. (ctf_set_array): Likewise. (ctf_update): Likewise. (ctf_snapshot): Likewise. (ctf_rollback): Likewise. (ctf_discard): Likewise. (ctf_write): Likewise. (ctf_gzwrite): Likewise. (ctf_compress_write): Likewise.
2019-04-24 05:45:46 +08:00
extern int ctf_compress_write (ctf_file_t * fp, int fd);
extern unsigned char *ctf_write_mem (ctf_file_t *, size_t *, size_t threshold);
libctf: add the ctf_link machinery This is the start of work on the core of the linking mechanism for CTF sections. This commit handles the type and string sections. The linker calls these functions in sequence: ctf_link_add_ctf: to add each CTF section in the input in turn to a newly-created ctf_file_t (which will appear in the output, and which itself will become the shared parent that contains types that all TUs have in common (in all link modes) and all types that do not have conflicting definitions between types (by default). Input files that are themselves products of ld -r are supported, though this is not heavily tested yet. ctf_link: called once all input files are added to merge the types in all the input containers into the output container, eliminating duplicates. ctf_link_add_strtab: called once the ELF string table is finalized and all its offsets are known, this calls a callback provided by the linker which returns the string content and offset of every string in the ELF strtab in turn: all these strings which appear in the input CTF strtab are eliminated from it in favour of the ELF strtab: equally, any strings that only appear in the input strtab will reappear in the internal CTF strtab of the output. ctf_link_shuffle_syms (not yet implemented): called once the ELF symtab is finalized, this calls a callback provided by the linker which returns information on every symbol in turn as a ctf_link_sym_t. This is then used to shuffle the function info and data object sections in the CTF section into symbol table order, eliminating the index sections which map those sections to symbol names before that point. Currently just returns ECTF_NOTYET. ctf_link_write: Returns a buffer containing either a serialized ctf_file_t (if there are no types with conflicting definitions in the object files in the link) or a ctf_archive_t containing a large ctf_file_t (the common types) and a bunch of small ones named after individual CUs in which conflicting types are found (containing the conflicting types, and all types that reference them). A threshold size above which compression takes place is passed as one parameter. (Currently, only gzip compression is supported, but I hope to add lzma as well.) Lifetime rules for this are simple: don't close the input CTF files until you've called ctf_link for the last time. We do not assume that symbols or strings passed in by the callback outlast the call to ctf_link_add_strtab or ctf_link_shuffle_syms. Right now, the duplicate elimination mechanism is the one already present as part of the ctf_add_type function, and is not particularly good: it misses numerous actual duplicates, and the conflicting-types detection hardly ever reports that types conflict, even when they do (one of them just tends to get silently dropped): it is also very slow. This will all be fixed in the next few weeks, but the fix hardly touches any of this code, and the linker does work without it, just not as well as it otherwise might. (And when no CTF section is present, there is no effect on performance, of course. So only people using a trunk GCC with not-yet-committed patches will even notice. By the time it gets upstream, things should be better.) v3: Fix error handling. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (struct ctf_link_sym): New, a symbol in flight to the libctf linking machinery. (CTF_LINK_SHARE_UNCONFLICTED): New. (CTF_LINK_SHARE_DUPLICATED): New. (ECTF_LINKADDEDLATE): New, replacing ECTF_UNUSED. (ECTF_NOTYET): New, a 'not yet implemented' message. (ctf_link_add_ctf): New, add an input file's CTF to the link. (ctf_link): New, merge the type and string sections. (ctf_link_strtab_string_f): New, callback for feeding strtab info. (ctf_link_iter_symbol_f): New, callback for feeding symtab info. (ctf_link_add_strtab): New, tell the CTF linker about the ELF strtab's strings. (ctf_link_shuffle_syms): New, ask the CTF linker to shuffle its symbols into symtab order. (ctf_link_write): New, ask the CTF linker to write the CTF out. libctf/ * ctf-link.c: New file, linking of the string and type sections. * Makefile.am (libctf_a_SOURCES): Add it. * Makefile.in: Regenerate. * ctf-impl.h (ctf_file_t): New fields ctf_link_inputs, ctf_link_outputs. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-error.c (_ctf_errlist): Updated with new errors.
2019-07-14 04:06:55 +08:00
extern int ctf_link_add_ctf (ctf_file_t *, ctf_archive_t *, const char *);
extern int ctf_link (ctf_file_t *, int share_mode);
typedef const char *ctf_link_strtab_string_f (uint32_t *offset, void *arg);
extern int ctf_link_add_strtab (ctf_file_t *, ctf_link_strtab_string_f *,
void *);
typedef ctf_link_sym_t *ctf_link_iter_symbol_f (ctf_link_sym_t *dest,
void *arg);
extern int ctf_link_shuffle_syms (ctf_file_t *, ctf_link_iter_symbol_f *,
void *);
extern unsigned char *ctf_link_write (ctf_file_t *, size_t *size,
size_t threshold);
extern void ctf_setdebug (int debug);
extern int ctf_getdebug (void);
#ifdef __cplusplus
}
#endif
#endif /* _CTF_API_H */