The first two of these allow you to get function type info and args out
of the types section give a type ID: astonishingly, this was missing
from libctf before now: so even though types of kind CTF_K_FUNCTION were
supported, you couldn't find out anything about them. (The existing
ctf_func_info and ctf_func_args only allow you to get info about
functions in the function section, i.e. given symbol table indexes, not
type IDs.)
The second of these allows you to get the raw undecorated name out of
the CTF section (strdupped for safety) without traversing subtypes to
build a full C identifier out of it. It's useful for things that are
already tracking the type kind etc and just need an unadorned name.
include/
* ctf-api.h (ECTF_NOTFUNC): Fix description.
(ctf_func_type_info): New.
(ctf_func_type_args): Likewise.
libctf/
* ctf-types.c (ctf_type_aname_raw): New.
(ctf_func_type_info): Likewise.
(ctf_func_type_args): Likewise.
* ctf-error.c (_ctf_errlist): Fix description.
Not all platforms have it. Use libiberty xstrndup() instead.
(The include of libiberty.h happens in an unusual place due to the
requirements of synchronization of most source files between this
project and another that does not use libiberty. It serves to pull
libiberty.h in for all source files in libctf/, which does the trick.)
Tested on x86_64-pc-linux-gnu, x86_64-unknown-freebsd12.0,
sparc-sun-solaris2.11, i686-pc-cygwin, i686-w64-mingw32.
libctf/
* ctf-decls.h: Include <libiberty.h>.
* ctf-lookup.c (ctf_lookup_by_name): Call xstrndup(), not strndup().
- 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.
These functions allow you to look up types given a name in a simple
subset of C declarator syntax (no function pointers), to look up the
types of variables given a name, and to look up the types of data
objects and the type signatures of functions given symbol table offsets.
(Despite its name, one function in this commit, ctf_lookup_symbol_name(),
is for the internal use of libctf only, and does not appear in any
public header files.)
libctf/
* ctf-lookup.c (isqualifier): New.
(ctf_lookup_by_name): Likewise.
(struct ctf_lookup_var_key): Likewise.
(ctf_lookup_var): Likewise.
(ctf_lookup_variable): Likewise.
(ctf_lookup_symbol_name): Likewise.
(ctf_lookup_by_symbol): Likewise.
(ctf_func_info): Likewise.
(ctf_func_args): Likewise.
include/
* ctf-api.h (ctf_func_info): New.
(ctf_func_args): Likewise.
(ctf_lookup_by_symbol): Likewise.
(ctf_lookup_by_symbol): Likewise.
(ctf_lookup_variable): Likewise.
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.
Nick Alcock
Jose E. Marchesi