libctf: creation functions
authorNick Alcock <nick.alcock@oracle.com>
Tue, 23 Apr 2019 21:45:46 +0000 (22:45 +0100)
committerNick Alcock <nick.alcock@oracle.com>
Tue, 28 May 2019 16:07:40 +0000 (17:07 +0100)
commit47d546f427d0d3bf9f503b5b118ae05b49d73d28
tree69f964b1297b2260e92412ca31f8941159ddebfe
parenta5be9bbe896d4adb6077e9bb2ebcaaa4426bdde1
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.
include/ChangeLog
include/ctf-api.h
libctf/ChangeLog
libctf/ctf-create.c [new file with mode: 0644]
libctf/ctf-lookup.c [new file with mode: 0644]