From 9ea82bfdd612081e21b38ea89d9bb0f836d92814 Mon Sep 17 00:00:00 2001 From: Nick Alcock Date: Tue, 7 May 2024 16:23:33 +0100 Subject: include, libctf: add a bunch of documentation to ctf-api.h Hopefully this library is no longer quite so much a "you have to look in the source to understand anything" library. No semantic changes, though some functions have been moved around for clarity. include/ ctf-api.h: Add comments. --- include/ctf-api.h | 468 ++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 418 insertions(+), 50 deletions(-) (limited to 'include') diff --git a/include/ctf-api.h b/include/ctf-api.h index 5f55e1c..0d7f584 100644 --- a/include/ctf-api.h +++ b/include/ctf-api.h @@ -312,9 +312,7 @@ extern ctf_next_t *ctf_next_copy (ctf_next_t *); /* 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_dict_t's directly, and cannot - be used on CTF archives. + archive with one member named '.ctf'. Some of these functions take raw symtab and strtab section content in the form of ctf_sect_t structures. For CTF in ELF files, these should be @@ -330,18 +328,65 @@ extern ctf_archive_t *ctf_fdopen (int fd, const char *filename, extern ctf_archive_t *ctf_open (const char *filename, const char *target, int *errp); extern void ctf_close (ctf_archive_t *); + +/* Return the data, symbol, or string sections used by a given CTF dict. */ extern ctf_sect_t ctf_getdatasect (const ctf_dict_t *); extern ctf_sect_t ctf_getsymsect (const ctf_dict_t *); extern ctf_sect_t ctf_getstrsect (const ctf_dict_t *); + +/* Symbol sections have an endianness which may be different from the + endianness of the CTF dict. Called for you by ctf_open and ctf_fdopen, + but direct calls to ctf_bufopen etc with symbol sections provided must + do so explicitly. */ + extern void ctf_symsect_endianness (ctf_dict_t *, int little_endian); -extern ctf_archive_t *ctf_get_arc (const ctf_dict_t *); +extern void ctf_arc_symsect_endianness (ctf_archive_t *, int little_endian); + +/* Open CTF archives from files or raw section data, and close them again. + Closing may munmap() the data making up the archive, so should not be + done until all dicts are finished with and closed themselves. + + Almost all functions that open archives will also open raw CTF dicts, which + are treated as if they were archives with only one member. */ + extern ctf_archive_t *ctf_arc_open (const char *, int *); extern ctf_archive_t *ctf_arc_bufopen (const ctf_sect_t *, const ctf_sect_t *, const ctf_sect_t *, int *); -extern void ctf_arc_symsect_endianness (ctf_archive_t *, int little_endian); extern void ctf_arc_close (ctf_archive_t *); + +/* Get the archive a given dictionary came from (if any). */ + +extern ctf_archive_t *ctf_get_arc (const ctf_dict_t *); + +/* Return the number of members in an archive. */ + +extern size_t ctf_archive_count (const ctf_archive_t *); + +/* Open a dictionary with a given name, given a CTF archive and + optionally symbol and string table sections to accompany it (if the + archive was oriiginally opened from an ELF file via ctf_open*, or + if string or symbol tables were explicitly passed when the archive + was opened, this can be used to override that choice). The dict + should be closed with ctf_dict_close() when done. + + (The low-level functions ctf_simple_open and ctf_bufopen return + ctf_dict_t's directly, and cannot be used on CTF archives: use these + functions instead.) */ + +extern ctf_dict_t *ctf_dict_open (const ctf_archive_t *, + const char *, int *); +extern ctf_dict_t *ctf_dict_open_sections (const ctf_archive_t *, + const ctf_sect_t *, + const ctf_sect_t *, + const char *, int *); + +/* Look up symbols' types in archives by index or name, returning the dict + and optionally type ID in which the type is found. Lookup results are + cached so future lookups are faster. Needs symbol tables and (for name + lookups) string tables to be known for this CTF archive. */ + extern ctf_dict_t *ctf_arc_lookup_symbol (ctf_archive_t *, unsigned long symidx, ctf_id_t *, int *errp); @@ -349,16 +394,11 @@ extern ctf_dict_t *ctf_arc_lookup_symbol_name (ctf_archive_t *, const char *name, ctf_id_t *, int *errp); extern void ctf_arc_flush_caches (ctf_archive_t *); -extern ctf_dict_t *ctf_dict_open (const ctf_archive_t *, - const char *, int *); -extern ctf_dict_t *ctf_dict_open_sections (const ctf_archive_t *, - const ctf_sect_t *, - const ctf_sect_t *, - const char *, int *); -extern size_t ctf_archive_count (const ctf_archive_t *); -/* The next functions return or close real CTF files, or write out CTF archives, - not opaque containers around either. */ +/* The next functions return or close real CTF files, or write out CTF + archives, not archives or ELF files containing CTF content. As with + ctf_dict_open_sections, they can be passed symbol and string table + sections. */ extern ctf_dict_t *ctf_simple_open (const char *, size_t, const char *, size_t, size_t, const char *, size_t, int *); @@ -367,73 +407,226 @@ extern ctf_dict_t *ctf_bufopen (const ctf_sect_t *, const ctf_sect_t *, extern void ctf_ref (ctf_dict_t *); extern void ctf_dict_close (ctf_dict_t *); -extern int ctf_arc_write (const char *, ctf_dict_t **, size_t, - const char **, size_t); -extern int ctf_arc_write_fd (int, ctf_dict_t **, size_t, const char **, - size_t); +/* CTF dicts may be in a parent/child relationship, where the child dicts + contain the name of their originating compilation unit and the name of + their parent. Dicts opened from CTF archives have this relationship set + up already, but if opening via raw low-level calls, you need to figure + out which dict is the parent and set it on the child via ctf_import(). */ extern const char *ctf_cuname (ctf_dict_t *); -extern int ctf_cuname_set (ctf_dict_t *, const char *); extern ctf_dict_t *ctf_parent_dict (ctf_dict_t *); extern const char *ctf_parent_name (ctf_dict_t *); -extern int ctf_parent_name_set (ctf_dict_t *, const char *); extern int ctf_type_isparent (ctf_dict_t *, ctf_id_t); extern int ctf_type_ischild (ctf_dict_t *, ctf_id_t); - extern int ctf_import (ctf_dict_t *, ctf_dict_t *); + +/* Set these names (used when creating dicts). */ + +extern int ctf_cuname_set (ctf_dict_t *, const char *); +extern int ctf_parent_name_set (ctf_dict_t *, const char *); + +/* Set and get the CTF data model (see above). */ + extern int ctf_setmodel (ctf_dict_t *, int); extern int ctf_getmodel (ctf_dict_t *); +/* CTF dicts can carry a single (in-memory-only) non-persistent pointer to + arbitrary data. No meaning is attached to this data and the dict does + not own it: nothing is done to it when the dict is closed. */ + extern void ctf_setspecific (ctf_dict_t *, void *); extern void *ctf_getspecific (ctf_dict_t *); +/* Error handling. ctf dicts carry a system errno value or one of the + CTF_ERRORS above, which are returned via ctf_errno. The return value of + ctf_errno is only meaningful when the immediately preceding CTF function + call returns an error code. + + There are four possible sorts of error return: + + - From opening functions, a return value of NULL and the error returned + via an errp instead of via ctf_errno; all other functions return return + errors via ctf_errno. + + - Functions returning a ctf_id_t are in error if the return value == CTF_ERR + - Functions returning an int are in error if their return value < 0 + - Functions returning a pointer are in error if their return value == + NULL. */ + extern int ctf_errno (ctf_dict_t *); extern const char *ctf_errmsg (int); + +/* Return the version of CTF dicts written by writeout functions. The + argument must currently be zero. All dicts with versions below the value + returned by this function can be read by the library. CTF dicts written + by other non-GNU CTF libraries (e.g. that in FreeBSD) are not compatible + and cannot be read by this library. */ + extern int ctf_version (int); +/* Given a symbol table index corresponding to a function symbol, return info on + the type of a given function's arguments or return value. Vararg functions + have a final arg with CTF_FUNC_VARARG on in ctc_flags. */ + extern int ctf_func_info (ctf_dict_t *, unsigned long, ctf_funcinfo_t *); extern int ctf_func_args (ctf_dict_t *, unsigned long, uint32_t, ctf_id_t *); + +/* As above, but for CTF_K_FUNCTION types in CTF dicts. */ + extern int ctf_func_type_info (ctf_dict_t *, ctf_id_t, ctf_funcinfo_t *); extern int ctf_func_type_args (ctf_dict_t *, ctf_id_t, uint32_t, ctf_id_t *); -extern ctf_id_t ctf_lookup_by_name (ctf_dict_t *, const char *); +/* Look up function or data symbols by name and return their CTF type ID, + if any. (For both function symbols and data symbols that are function + pointers, the types are of kind CTF_K_FUNCTION.) */ + extern ctf_id_t ctf_lookup_by_symbol (ctf_dict_t *, unsigned long); extern ctf_id_t ctf_lookup_by_symbol_name (ctf_dict_t *, const char *); + +/* Traverse all (function or data) symbols in a dict, one by one, and return the + type of each and (if NAME is non-NULL) optionally its name. + + This is the first of a family of _next iterators that all work in similar + ways: the ctf_next_t iterator arg must be the address of a variable whose + value is NULL on first call, and will be set to NULL again once iteration has + completed (which also returns CTF_ERR as the type and sets the error + ECTF_NEXT_END on the dict). If you want to exit earlier, call + ctf_next_destroy on the iterator. */ + extern ctf_id_t ctf_symbol_next (ctf_dict_t *, ctf_next_t **, const char **name, int functions); + +/* Look up a type by name: some simple C type parsing is done, but this is by no + means comprehensive. Structures, unions and enums need "struct ", "union " + or "enum " on the front, as usual in C. */ + +extern ctf_id_t ctf_lookup_by_name (ctf_dict_t *, const char *); + +/* Look up a variable, which is a name -> type mapping with no specific + relationship to a symbol table. Before linking, everything with types in the + symbol table will be in the variable table as well; after linking, only those + typed functions and data objects that are not asssigned to symbols by the + linker are left in the variable table here. */ + extern ctf_id_t ctf_lookup_variable (ctf_dict_t *, const char *); +/* Type lookup functions. */ + +/* Strip qualifiers and typedefs off a type, returning the base type. + + Stripping also stops when we hit slices (see ctf_add_slice below), so it is + possible (given a chain looking like const -> slice -> typedef -> int) to + still have a typedef after you're done with this, but in that case it is a + typedef of a type with a *different width* (because this slice has not been + applied to it). + + Most of the time you don't need to call this: the type-querying functions + will do it for you (as noted below). */ + extern ctf_id_t ctf_type_resolve (ctf_dict_t *, ctf_id_t); + +/* Get the name of a type, including any cvr-quals, and return it as a new + dynamically-allocated string. */ + extern char *ctf_type_aname (ctf_dict_t *, ctf_id_t); + +/* As above, but with no cvr-quals. */ + extern char *ctf_type_aname_raw (ctf_dict_t *, ctf_id_t); + +extern const char *ctf_type_name_raw (ctf_dict_t *, ctf_id_t); + +/* Like ctf_type_aname, but print the string into the passed buffer, truncating + if necessary and setting ECTF_NAMELEN on the errno: return the actual number + of bytes needed (not including the trailing \0). Consider using + ctf_type_aname instead. */ + extern ssize_t ctf_type_lname (ctf_dict_t *, ctf_id_t, char *, size_t); + +/* Like ctf_type_lname, but return the string, or NULL if truncated. + Consider using ctf_type_aname instead. */ + extern char *ctf_type_name (ctf_dict_t *, ctf_id_t, char *, size_t); -extern const char *ctf_type_name_raw (ctf_dict_t *, ctf_id_t); + +/* Return the size or alignment of a type. Types with no meaningful size, like + function types, return 0 as their size; incomplete types set ECTF_INCOMPLETE. + The type is resolved for you, so cvr-quals and typedefs can be passsed in. */ + extern ssize_t ctf_type_size (ctf_dict_t *, ctf_id_t); extern ssize_t ctf_type_align (ctf_dict_t *, ctf_id_t); + +/* Return the kind of a type (CTF_K_* constant). Slices are considered to be + the kind they are a slice of. Forwards to incomplete structs, etc, return + CTF_K_FORWARD (but deduplication resolves most forwards to their concrete + types). */ + extern int ctf_type_kind (ctf_dict_t *, ctf_id_t); + +/* Return the kind of a type (CTF_K_* constant). Slices are considered to be + the kind they are a slice of; forwards are considered to be the kind they are + a forward of. */ + extern int ctf_type_kind_forwarded (ctf_dict_t *, ctf_id_t); + +/* Return the type a pointer, typedef, cvr-qual, or slice refers to, or return + an ECTF_NOTREF error otherwise. ctf_type_kind pretends that slices are + actually the type they are a slice of: this is usually want you want, but if + you want to find out if a type was actually a slice of some (usually-wider) + base type, you can call ctf_type_reference on it: a non-error return means + it was a slice. */ + extern ctf_id_t ctf_type_reference (ctf_dict_t *, ctf_id_t); -extern ctf_id_t ctf_type_pointer (ctf_dict_t *, ctf_id_t); + +/* Return the encoding of a given type. No attempt is made to resolve the + type first, so passing in typedefs etc will yield an error. */ + extern int ctf_type_encoding (ctf_dict_t *, ctf_id_t, ctf_encoding_t *); + +/* Given a type, return some other type that is a pointer to this type (if any + exists), or return ECTF_NOTYPE otherwise. If non exists, try resolving away + typedefs and cvr-quals and check again (so if you call this on foo_t, you + might get back foo *). No attempt is made to hunt for pointers to qualified + versions of the type passed in. */ + +extern ctf_id_t ctf_type_pointer (ctf_dict_t *, ctf_id_t); + +/* Return 1 if two types are assignment-compatible. */ + +extern int ctf_type_compat (ctf_dict_t *, ctf_id_t, ctf_dict_t *, ctf_id_t); + +/* Recursively visit the members of any type, calling the ctf_visit_f for each. */ + extern int ctf_type_visit (ctf_dict_t *, ctf_id_t, ctf_visit_f *, void *); + +/* Comparison function that defines an ordering over types. If the types are in + different dicts, the ordering may vary between different openings of the same + dicts. */ + extern int ctf_type_cmp (ctf_dict_t *, ctf_id_t, ctf_dict_t *, ctf_id_t); -extern int ctf_type_compat (ctf_dict_t *, ctf_id_t, ctf_dict_t *, ctf_id_t); -extern int ctf_member_info (ctf_dict_t *, ctf_id_t, const char *, - ctf_membinfo_t *); -extern int ctf_array_info (ctf_dict_t *, ctf_id_t, ctf_arinfo_t *); +/* Get the name of an enumerator given its value, or vice versa. If many + enumerators have the same value, the first with that value is returned. */ extern const char *ctf_enum_name (ctf_dict_t *, ctf_id_t, int); extern int ctf_enum_value (ctf_dict_t *, ctf_id_t, const char *, int *); -extern void ctf_label_set (ctf_dict_t *, const char *); -extern const char *ctf_label_get (ctf_dict_t *); +/* Get the size and member type of an array. */ -extern const char *ctf_label_topmost (ctf_dict_t *); -extern int ctf_label_info (ctf_dict_t *, const char *, ctf_lblinfo_t *); +extern int ctf_array_info (ctf_dict_t *, ctf_id_t, ctf_arinfo_t *); + +/* Get info on specific named members of structs or unions, and count the number + of members in a struct, union, or enum. */ +extern int ctf_member_info (ctf_dict_t *, ctf_id_t, const char *, + ctf_membinfo_t *); extern int ctf_member_count (ctf_dict_t *, ctf_id_t); + +/* Iterators. */ + +/* ctf_member_next is a _next-style iterator that can additionally traverse into + the members of unnamed structs nested within this struct as if they were + direct members, if CTF_MN_RECURSE is passed in the flags. */ + extern int ctf_member_iter (ctf_dict_t *, ctf_id_t, ctf_member_f *, void *); extern ssize_t ctf_member_next (ctf_dict_t *, ctf_id_t, ctf_next_t **, const char **name, ctf_id_t *membtype, @@ -441,26 +634,58 @@ extern ssize_t ctf_member_next (ctf_dict_t *, ctf_id_t, ctf_next_t **, extern int ctf_enum_iter (ctf_dict_t *, ctf_id_t, ctf_enum_f *, void *); extern const char *ctf_enum_next (ctf_dict_t *, ctf_id_t, ctf_next_t **, int *); + +/* Iterate over all types in a dict. ctf_type_iter_all recurses over all types: + ctf_type_iter recurses only over types with user-visible names (for which + CTF_ADD_ROOT was passed). All such types are returned, even if they are + things like pointers that intrinsically have no name: this is the only effect + of CTF_ADD_ROOT for such types. ctf_type_next allows you to choose whether + to see hidden types or not with the want_hidden arg: if set, the flag (if + passed) returns the hidden state of each type in turn. */ + extern int ctf_type_iter (ctf_dict_t *, ctf_type_f *, void *); extern int ctf_type_iter_all (ctf_dict_t *, ctf_type_all_f *, void *); extern ctf_id_t ctf_type_next (ctf_dict_t *, ctf_next_t **, int *flag, int want_hidden); -extern int ctf_label_iter (ctf_dict_t *, ctf_label_f *, void *); -extern int ctf_label_next (ctf_dict_t *, ctf_next_t **, const char **); /* TBD */ + extern int ctf_variable_iter (ctf_dict_t *, ctf_variable_f *, void *); extern ctf_id_t ctf_variable_next (ctf_dict_t *, ctf_next_t **, const char **); + +/* ctf_archive_iter and ctf_archive_next open each member dict for you, + automatically importing any parent dict as usual: ctf_archive_iter closes the + dict on return from ctf_archive_member_f, but for ctf_archive_next the caller + must close each dict returned. If skip_parent is set, the parent dict is + skipped on the basis that it's already been seen in every child dict (but if + no child dicts exist, this will lead to nothing being returned). + + If an open fails, ctf_archive_iter returns -1 early (losing the error), but + ctf_archive_next both passes back the error in the passed errp and allows you + to iterate past errors (until the usual ECTF_NEXT_END is returned). */ + extern int ctf_archive_iter (const ctf_archive_t *, ctf_archive_member_f *, void *); extern ctf_dict_t *ctf_archive_next (const ctf_archive_t *, ctf_next_t **, const char **, int skip_parent, int *errp); -/* 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 +/* Pass the raw content of each archive member in turn to + ctf_archive_raw_member_f. + + 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. */ + to deal with non-archives at all. (There is currently no _next analogue of + this function.) */ + extern int ctf_archive_raw_iter (const ctf_archive_t *, ctf_archive_raw_member_f *, void *); + +/* Dump the contents of a section in a CTF dict. STATE is an + iterator which should be a pointer to a variable set to NULL. The decorator + is called with each line in turn and can modify it or allocate and return a + new one. ctf_dump accumulates all the results and returns a single giant + multiline string. */ + extern char *ctf_dump (ctf_dict_t *, ctf_dump_state_t **state, ctf_sect_names_t sect, ctf_dump_decorate_f *, void *arg); @@ -471,6 +696,19 @@ extern char *ctf_dump (ctf_dict_t *, ctf_dump_state_t **state, extern char *ctf_errwarning_next (ctf_dict_t *, ctf_next_t **, int *is_warning, int *errp); +/* Creation. */ + +/* Create a new, empty dict. If creation fails, return NULL and put a CTF error + code in the passed-in int (if set). */ +extern ctf_dict_t *ctf_create (int *); + +/* Add specific types to a dict. You can add new types to any dict, but you can + only add members to types that have been added since this dict was read in + (you cannot read in a dict, look up a type in it, then add members to + it). All adding functions take a uint32_t CTF_ADD_ROOT / CTF_ADD_NONROOT + flag to indicate whether this type should be visible to name lookups via + ctf_lookup_by_name et al. */ + extern ctf_id_t ctf_add_array (ctf_dict_t *, uint32_t, const ctf_arinfo_t *); extern ctf_id_t ctf_add_const (ctf_dict_t *, uint32_t, ctf_id_t); @@ -485,22 +723,49 @@ extern ctf_id_t ctf_add_function (ctf_dict_t *, uint32_t, const ctf_funcinfo_t *, const ctf_id_t *); extern ctf_id_t ctf_add_integer (ctf_dict_t *, uint32_t, const char *, const ctf_encoding_t *); + +/* Add a "slice", which wraps some integral type and changes its encoding + (useful for bitfields, etc). In most respects slices are treated the same + kind as the type they wrap: only ctf_type_reference can see the difference, + returning the wrapped type. */ + extern ctf_id_t ctf_add_slice (ctf_dict_t *, uint32_t, ctf_id_t, const ctf_encoding_t *); extern ctf_id_t ctf_add_pointer (ctf_dict_t *, uint32_t, ctf_id_t); extern ctf_id_t ctf_add_type (ctf_dict_t *, ctf_dict_t *, ctf_id_t); extern ctf_id_t ctf_add_typedef (ctf_dict_t *, uint32_t, const char *, ctf_id_t); extern ctf_id_t ctf_add_restrict (ctf_dict_t *, uint32_t, ctf_id_t); + +/* Struct and union addition. Straight addition uses possibly-confusing rules + to guess the final size of the struct/union given its members: to explicitly + state the size of the struct or union (to report compiler-generated padding, + etc) use the _sized variants. */ + extern ctf_id_t ctf_add_struct (ctf_dict_t *, uint32_t, const char *); extern ctf_id_t ctf_add_union (ctf_dict_t *, uint32_t, const char *); extern ctf_id_t ctf_add_struct_sized (ctf_dict_t *, uint32_t, const char *, size_t); extern ctf_id_t ctf_add_union_sized (ctf_dict_t *, uint32_t, const char *, size_t); + +/* Note that CTF cannot encode a given type. This usually returns an + ECTF_NONREPRESENTABLE error when queried. Mostly useful for struct members, + variables, etc, to point to. */ + extern ctf_id_t ctf_add_unknown (ctf_dict_t *, uint32_t, const char *); extern ctf_id_t ctf_add_volatile (ctf_dict_t *, uint32_t, ctf_id_t); +/* Add an enumerator to an enum (the name is a misnomer). We do not currently + validate that enumerators have unique names, even though C requires it: in + future this may change. */ + extern int ctf_add_enumerator (ctf_dict_t *, ctf_id_t, const char *, int); + +/* Add a member to a struct or union, either at the next available offset (with + suitable padding for the alignment) or at a specific offset, and possibly + with a specific encoding (creating a slice for you). Offsets need not be + unique, and need not be added in ascending order. */ + extern int ctf_add_member (ctf_dict_t *, ctf_id_t, const char *, ctf_id_t); extern int ctf_add_member_offset (ctf_dict_t *, ctf_id_t, const char *, ctf_id_t, unsigned long); @@ -510,47 +775,135 @@ extern int ctf_add_member_encoded (ctf_dict_t *, ctf_id_t, const char *, extern int ctf_add_variable (ctf_dict_t *, const char *, ctf_id_t); +/* Set the size and member and index types of an array. */ + +extern int ctf_set_array (ctf_dict_t *, ctf_id_t, const ctf_arinfo_t *); + +/* Add a function oor object symbol type with a particular name, without saying + anything about the actual symbol index. (The linker will then associate them + with actual symbol indexes using the ctf_link functions below.) */ + extern int ctf_add_objt_sym (ctf_dict_t *, const char *, ctf_id_t); extern int ctf_add_func_sym (ctf_dict_t *, const char *, ctf_id_t); -extern int ctf_set_array (ctf_dict_t *, ctf_id_t, const ctf_arinfo_t *); +/* Snapshot/rollback. Call ctf_update to snapshot the state of a dict: + a later call to ctf_discard then deletes all types added since (but not new + members, enumerands etc). Call ctf_snapshot to return a snapshot ID: pass + one of these IDs to ctf_rollback to discard all types added since the + corresponding call to ctf_snapshot. */ -extern ctf_dict_t *ctf_create (int *); extern int ctf_update (ctf_dict_t *); extern ctf_snapshot_id_t ctf_snapshot (ctf_dict_t *); extern int ctf_rollback (ctf_dict_t *, ctf_snapshot_id_t); extern int ctf_discard (ctf_dict_t *); + +/* Dict writeout. + + ctf_write: write out an uncompressed dict to an fd. + ctf_compress_write: write out a compressed dict to an fd (currently always + gzip, but this may change in future). + ctf_write_mem: write out a dict to a buffer and return it and its size, + compressing it if its uncompressed size is over THRESHOLD. */ + extern int ctf_write (ctf_dict_t *, int); -extern int ctf_gzwrite (ctf_dict_t *fp, gzFile fd); extern int ctf_compress_write (ctf_dict_t * fp, int fd); extern unsigned char *ctf_write_mem (ctf_dict_t *, size_t *, size_t threshold); -extern int ctf_link_add_ctf (ctf_dict_t *, ctf_archive_t *, const char *); -/* The variable filter should return nonzero if a variable should not - appear in the output. */ -typedef int ctf_link_variable_filter_f (ctf_dict_t *, const char *, ctf_id_t, - void *); -extern int ctf_link_set_variable_filter (ctf_dict_t *, - ctf_link_variable_filter_f *, void *); +/* Create a CTF archive named FILE from CTF_DICTS inputs with NAMES (or write it + to the passed-in fd). */ + +extern int ctf_arc_write (const char *file, ctf_dict_t **ctf_dicts, size_t, + const char **names, size_t); +extern int ctf_arc_write_fd (int, ctf_dict_t **, size_t, const char **, + size_t); + +/* Linking. These functions are used by ld to link .ctf sections in input + object files into a single .ctf section which is an archive possibly + containing members containing types whose names collide across multiple + compilation units, but they are usable by other programs as well and are not + private to the linker. */ + +/* Add a CTF archive to the link with a given NAME (usually the name of the + containing object file). The dict added to is usually a new dict created + with ctf_create which will be filled with types corresponding to the shared + dict in the output (conflicting types in child dicts in the output archive + are stored in internal space inside this dict, but are not easily visible + until after ctf_link_write below). + + The NAME need not be unique (but usually is). */ + +extern int ctf_link_add_ctf (ctf_dict_t *, ctf_archive_t *, const char *name); + +/* Do the deduplicating link, filling the dict with types. The FLAGS are the + CTF_LINK_* flags above. */ + extern int ctf_link (ctf_dict_t *, int flags); + +/* Symtab linker handling, called after ctf_link to set up the symbol type + information used by ctf_*_lookup_symbol. */ + +/* Add strings to the link from the ELF string table, repeatedly calling + ADD_STRING to add each string and its corresponding offset in turn. */ + typedef const char *ctf_link_strtab_string_f (uint32_t *offset, void *arg); -extern int ctf_link_add_strtab (ctf_dict_t *, ctf_link_strtab_string_f *, - void *); +extern int ctf_link_add_strtab (ctf_dict_t *, + ctf_link_strtab_string_f *add_string, void *); + +/* Note that a given symbol will be public with a given set of properties. + If the symbol has been added with that name via ctf_add_{func,objt}_sym, + this symbol type will end up in the symtypetabs and can be looked up via + ctf_*_lookup_symbol after the dict is read back in. */ + extern int ctf_link_add_linker_symbol (ctf_dict_t *, ctf_link_sym_t *); + +/* Impose an ordering on symbols, as defined by the strtab and symbol + added by earlier calls to the above two functions. */ + extern int ctf_link_shuffle_syms (ctf_dict_t *); + +/* Return the serialized form of this ctf_linked dict as a new + dynamically-allocated string, compressed if size over THRESHOLD. + + May be a CTF dict or a CTF archive (this library mostly papers over the + differences so you can open both the same way, treat both as ctf_archive_t + and so on). */ + extern unsigned char *ctf_link_write (ctf_dict_t *, size_t *size, size_t threshold); /* Specialist linker functions. These functions are not used by ld, but can be used by other programs making use of the linker machinery for other purposes - to customize its output. */ + to customize its output. Must be called befoore ctf_link. */ + +/* Add an entry to rename a given compilation unit to some other name. This + is only used if conflicting types are found in that compilation unit: they + will instead be placed in the child dict named TO. Many FROMs can map to one + TO: all the types are placed together in that dict, with any whose names + collide as a result being marked as non-root types. */ + extern int ctf_link_add_cu_mapping (ctf_dict_t *, const char *from, const char *to); + +/* Allow CTF archive names to be tweaked at the last minute before writeout. + Unlike cu-mappings, this cannot transform names so that they collide: it's + meant for unusual use cases that use names for archive members that are not + exactly the same as CU names but are modified in some systematic way. */ typedef char *ctf_link_memb_name_changer_f (ctf_dict_t *, const char *, void *); extern void ctf_link_set_memb_name_changer (ctf_dict_t *, ctf_link_memb_name_changer_f *, void *); +/* Filter out unwanted variables, which can be very voluminous, and (unlike + symbols) cause the CTF string table to grow to hold their names. The + variable filter should return nonzero if a variable should not appear in the + output. */ +typedef int ctf_link_variable_filter_f (ctf_dict_t *, const char *, ctf_id_t, + void *); +extern int ctf_link_set_variable_filter (ctf_dict_t *, + ctf_link_variable_filter_f *, void *); + +/* Turn debugging off and on, and get its value. This is the same as setting + LIBCTF_DEBUG in the environment. */ extern void ctf_setdebug (int debug); extern int ctf_getdebug (void); @@ -567,6 +920,21 @@ extern ctf_dict_t *ctf_arc_open_by_name_sections (const ctf_archive_t *, const ctf_sect_t *, const char *, int *); +/* Deprecated witeout function to write out a gzip-compressed dict. Unlike all + the other writeout functions, this even compresses the header (it has to, + since it's passed a gzFile), so the caller must also decompress it, since + ctf_open() etc cannot tell it is a CTF dict or how large it is before + decompression. */ + +extern int ctf_gzwrite (ctf_dict_t *fp, gzFile fd); + +/* Deprecated functions with no current use. */ + +extern const char *ctf_label_topmost (ctf_dict_t *); +extern int ctf_label_info (ctf_dict_t *, const char *, ctf_lblinfo_t *); +extern int ctf_label_iter (ctf_dict_t *, ctf_label_f *, void *); +extern int ctf_label_next (ctf_dict_t *, ctf_next_t **, const char **); /* TBD */ + #ifdef __cplusplus } #endif -- cgit v1.1