binutils-gdb

Commit Graph

Author	SHA1	Message	Date
Nick Alcock	44c70fb01f	libctf: add a comment explaining how to use ctf_open Specifically, tell users what to pass to those functions that accept raw section content, since it's fairly involved and easy to get wrong. (.dynsym / .dynstr when CTF_F_DYNSTR is set, otherwise .symtab / .strtab). include/ChangeLog: ctf-api.h (ctf_*open): Improve comment.	4 years ago
Alan Modra	a2c5833233	Update year range in copyright notice of binutils files The result of running etc/update-copyright.py --this-year, fixing all the files whose mode is changed by the script, plus a build with --enable-maintainer-mode --enable-cgen-maint=yes, then checking out /po/.pot which we don't update frequently. The copy of cgen was with commit d1dd5fcc38ead reverted as that commit breaks building of bfp opcodes files.	4 years ago
Nick Alcock	49da556c65	libctf, include: support an alternative encoding for nonrepresentable types Before now, types that could not be encoded in CTF were represented as references to type ID 0, which does not itself appear in the dictionary. This choice is annoying in several ways, principally that it forces generators and consumers of CTF to grow special cases for types that are referenced in valid dicts but don't appear. Allow an alternative representation (which will become the only representation in format v4) whereby nonrepresentable types are encoded as actual types with kind CTF_K_UNKNOWN (an already-existing kind theoretically but not in practice used for padding, with value 0). This is backward-compatible, because CTF_K_UNKNOWN was not used anywhere before now: it was used in old-format function symtypetabs, but these were never emitted by any compiler and the code to handle them in libctf likely never worked and was removed last year, in favour of new-format symtypetabs that contain only type IDs, not type kinds. In order to link this type, we need an API addition to let us add types of unknown kind to the dict: we let them optionally have names so that GCC can emit many different unknown types and those types with identical names will be deduplicated together. There are also small tweaks to the deduplicator to actually dedup such types, to let opening of dicts with unknown types with names work, to return the ECTF_NONREPRESENTABLE error on resolution of such types (like ID 0), and to print their names as something useful but not a valid C identifier, mostly for the sake of the dumper. Tests added in the next commit. include/ChangeLog 2021-05-06 Nick Alcock <nick.alcock@oracle.com> * ctf.h (CTF_K_UNKNOWN): Document that it can be used for nonrepresentable types, not just padding. * ctf-api.h (ctf_add_unknown): New. libctf/ChangeLog 2021-05-06 Nick Alcock <nick.alcock@oracle.com> * ctf-open.c (init_types): Unknown types may have names. * ctf-types.c (ctf_type_resolve): CTF_K_UNKNOWN is as non-representable as type ID 0. (ctf_type_aname): Print unknown types. * ctf-dedup.c (ctf_dedup_hash_type): Do not early-exit for CTF_K_UNKNOWN types: they have real hash values now. (ctf_dedup_rwalk_one_output_mapping): Treat CTF_K_UNKNOWN types like other types with no referents: call the callback and do not skip them. (ctf_dedup_emit_type): Emit via... * ctf-create.c (ctf_add_unknown): ... this new function. * libctf.ver (LIBCTF_1.2): Add it.	5 years ago
Nick Alcock	8915c559d4	libctf, include: remove the nondeduplicating CTF linker The nondeduplicating CTF linker was kept around when the deduplicating one was added so that people had something to fall back to in case the deduplicating linker turned out to be buggy. It's now much more stable than the nondeduplicating linker, in addition to much faster, using much less memory and producing much better output. In addition, while libctf has a linker flag to invoke the nondeduplicating linker, ld does not expose it: the only way to turn it on within ld is an intentionally- undocumented environment variable. So we can remove it without any ABI or user-visibility concerns (the only thing we leave around is the CTF_LINK_NONDEDUP flag, which can easily be interpreted as "deduplicate less", though right now it does nothing). This lets us remove a lot of complexity associated with tracking filenames and CU names separately (something the deduplcating linker never bothered with, since the cunames are always reliable and ld never hands us useful filenames anyway) The biggest lacuna left behind is the ctf_type_mapping machinery, which slows down deduplicating links quite a lot. We can't just ditch it because ctf_add_type uses it: removing the slowdown from the deduplicating linker is a job for another commit. include/ChangeLog 2021-03-02 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (CTF_LINK_SHARE_DUPLICATED): Note that this might merely change how much deduplication is done. libctf/ChangeLog 2021-03-02 Nick Alcock <nick.alcock@oracle.com> * ctf-link.c (ctf_create_per_cu): Drop FILENAME now that it is always identical to CUNAME. (ctf_link_deduplicating_one_symtypetab): Adjust. (ctf_link_one_type): Remove. (ctf_link_one_input_archive_member): Likewise. (ctf_link_close_one_input_archive): Likewise. (ctf_link_one_input_archive): Likewise. (ctf_link): No longer call it. Drop CTF_LINK_NONDEDUP path. Improve header comment a bit (dicts, not files). Adjust ctf_create_per_cu call. (ctf_link_deduplicating_variables): Simplify. (ctf_link_in_member_cb_arg_t) <cu_name>: Remove. <in_input_cu_file>: Likewise. <in_fp_parent>: Likewise. <done_parent>: Likewise. (ctf_link_one_variable): Turn uses of in_file_name to in_cuname.	5 years ago
Nick Alcock	f4f60336da	libctf, include: find types of symbols by name The existing ctf_lookup_by_symbol and ctf_arc_lookup_symbol functions suffice to look up the types of symbols if the caller already has a symbol number. But the caller often doesn't have one of those and only knows the name of the symbol: also, in object files, the caller might not have a useful symbol number in any sense (and neither does libctf: the 'symbol number' we use in that case literally starts at 0 for the lexicographically first-sorted symbol in the symtypetab and counts those symbols, so it corresponds to nothing useful). This means that even though object files have a symtypetab (generated by the compiler or by ld -r), the only way we can look up anything in it is to iterate over all symbols in turn with ctf_symbol_next until we find the one we want. This is unhelpful and pointlessly inefficient. So add a pair of functions to look up symbols by name in a dict and in a whole archive: ctf_lookup_by_symbol_name and ctf_arc_lookup_symbol_name. These are identical to the existing functions except that they take symbol names rather than symbol numbers. To avoid insane repetition, we do some refactoring in the process, so that both ctf_lookup_by_symbol and ctf_arc_lookup_symbol turn into thin wrappers around internal functions that do both lookup by symbol index and lookup by name. This massively reduces code duplication because even the existing lookup-by-index stuff wants to use a name sometimes (when looking up in indexed sections), and the new lookup-by-name stuff has to turn it into an index sometimes (when looking up in non-indexed sections): doing it this way lets us share most of that. The actual name->index lookup is done by ctf_lookup_symbol_idx. We do not anticipate this lookup to be as heavily used as ld.so symbol lookup by many orders of magnitude, so using the ELF symbol hashes would probably take more time to read them than is saved by using the hashes, and it adds a lot of complexity. Instead, do a linear search for the symbol name, caching all the name -> index mappings as we go, so that future searches are likely to hit in the cache. To avoid having to repeat this search over and over in a CTF archive when ctf_arc_lookup_symbol_name is used, have cached archive lookups (the sort done by ctf_arc_lookup_symbol* and the ctf_archive_next iterator) pick out the first dict they cache in a given archive and store it in a new ctf_archive field, ctfi_crossdict_cache. This can be used to store cross-dictionary cached state that depends on things like the ELF symbol table rather than the contents of any one dict. ctf_lookup_symbol_idx then caches its name->index mappings in the dictionary named in the crossdict cache, if any, so that ctf_lookup_symbol_idx in other dicts in the same archive benefit from the previous linear search, and the symtab only needs to be scanned at most once. (Note that if you call ctf_lookup_by_symbol_name in one specific dict, and then follow it with a ctf_arc_lookup_symbol_name, the former will not use the crossdict cache because it's only populated by the dict opens in ctf_arc_lookup_symbol_name. This is harmless except for a small one-off waste of memory and time: it's only a cache, after all. We can fix this later by using the archive caching machinery more aggressively.) In ctf-archive, we do similar things, turning ctf_arc_lookup_symbol into a wrapper around a new function that does both index -> ID and name -> ID lookups across all dicts in an archive. We add a new ctfi_symnamedicts cache that maps symbol names to the ctf_dict_t * that it was found in (so that linear searches for symbols don't need to be repeated): but we also remove a cache, the ctfi_syms cache that was memoizing the actual ctf_id_t returned from every call to ctf_arc_lookup_symbol. This is pointless: all it saves is one call to ctf_lookup_by_symbol, and that's basically an array lookup and nothing more so isn't worth caching. (Equally, given that symbol -> index mappings are cached by ctf_lookup_by_symbol_name, those calls are nearly free after the first call, so there's no point caching the ctf_id_t in that case either.) We fix up one test that was doing manual symbol lookup to use ctf_arc_lookup_symbol instead, and enhance it to check that the caching layer is not totally broken: we also add a new test to do lookups in a .o file, and another to do lookups in an archive with conflicted types and make sure that sort of multi-dict lookup is actually working. include/ChangeLog 2021-02-17 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ctf_arc_lookup_symbol_name): New. (ctf_lookup_by_symbol_name): Likewise. libctf/ChangeLog 2021-02-17 Nick Alcock <nick.alcock@oracle.com> * ctf-impl.h (ctf_dict_t) <ctf_symhash>: New. <ctf_symhash_latest>: Likewise. (struct ctf_archive_internal) <ctfi_crossdict_cache>: New. <ctfi_symnamedicts>: New. <ctfi_syms>: Remove. (ctf_lookup_symbol_name): Remove. * ctf-lookup.c (ctf_lookup_symbol_name): Propagate errors from parent properly. Make static. (ctf_lookup_symbol_idx): New, linear search for the symbol name, cached in the crossdict cache's ctf_symhash (if available), or this dict's (otherwise). (ctf_try_lookup_indexed): Allow the symname to be passed in. (ctf_lookup_by_symbol): Turn into a wrapper around... (ctf_lookup_by_sym_or_name): ... this, supporting name lookup too, using ctf_lookup_symbol_idx in non-writable dicts. Special-case name lookup in dynamic dicts without reported symbols, which have no symtab or dynsymidx but where name lookup should still work. (ctf_lookup_by_symbol_name): New, another wrapper. * ctf-archive.c (enosym): Note that this is present in ctfi_symnamedicts too. (ctf_arc_close): Adjust for removal of ctfi_syms. Free the ctfi_symnamedicts. (ctf_arc_flush_caches): Likewise. (ctf_dict_open_cached): Memoize the first cached dict in the crossdict cache. (ctf_arc_lookup_symbol): Turn into a wrapper around... (ctf_arc_lookup_sym_or_name): ... this. No longer cache ctf_id_t lookups: just call ctf_lookup_by_symbol as needed (but still cache the dicts those lookups succeed in). Add lookup-by-name support, with dicts of successful lookups cached in ctfi_symnamedicts. Refactor the caching code a bit. (ctf_arc_lookup_symbol_name): New, another wrapper. * ctf-open.c (ctf_dict_close): Free the ctf_symhash. * libctf.ver (LIBCTF_1.2): New version. Add ctf_lookup_by_symbol_name, ctf_arc_lookup_symbol_name. * testsuite/libctf-lookup/enum-symbol.c (main): Use ctf_arc_lookup_symbol rather than looking up the name ourselves. Fish it out repeatedly, to make sure that symbol caching isn't broken. (symidx_64): Remove. (symidx_32): Remove. * testsuite/libctf-lookup/enum-symbol-obj.lk: Test symbol lookup in an unlinked object file (indexed symtypetab sections only). * testsuite/libctf-writable/symtypetab-nonlinker-writeout.c (try_maybe_reporting): Check symbol types via ctf_lookup_by_symbol_name as well as ctf_symbol_next. * testsuite/libctf-lookup/conflicting-type-syms.*: New test of lookups in a multi-dict archive.	5 years ago
Nick Alcock	caa170493e	libctf: prohibit nameless ints, floats, typedefs and forwards Now that "anonymous typedef nodes" have been extirpated, we can mandate that things that have names in C must have names in CTF too. (Unlike the no-forwards embarrassment, the deduplicator does nothing special with names: types that have names in C will have the same name in CTF. So we can assume that the CTF rules and the C rules are the same.) include/ChangeLog 2021-01-27 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ECTF_NONAME): New. (ECTF_NERR): Adjust. libctf/ChangeLog 2021-01-27 Nick Alcock <nick.alcock@oracle.com> * ctf-create.c (ctf_add_encoded): Add check for non-empty name. (ctf_add_forward): Likewise. (ctf_add_typedef): Likewise.	5 years ago
Nick Alcock	35a01a0454	libctf, ld: fix symtypetab and var section population under ld -r The variable section in a CTF dict is meant to contain the types of variables that do not appear in the symbol table (mostly file-scope static declarations). We implement this by having the compiler emit all potential data symbols into both sections, then delete those symbols from the variable section that correspond to data symbols the linker has reported. Unfortunately, the check for this in ctf_serialize is wrong: rather than checking the set of linker-reported symbols, we check the set of names in the data object symtypetab section: if the linker has reported no symbols at all (usually if ld -r has been run, or if a non-linker program that does not use symbol tables is calling ctf_link) this will include every single symbol, emptying the variable section completely. Worse, when ld -r is in use, we want to force writeout of every symtypetab entry on the inputs, in an indexed section, whether or not the linker has reported them, since this isn't a final link yet and the symbol table is not finalized (and may grow more symbols than the linker has yet reported). But the check for this is flawed too: we were relying on ctf_link_shuffle_syms not having been called if no symbols exist, but that function is always called by ld even when ld -r is in use: ctf_link_add_linker_symbol is the one that's not called when there are no symbols. We clearly need to rethink this. Using the emptiness of the set of reported symbols as a test for ld -r is just ugly: the linker already knows if ld -r is underway and can just tell us. So add a new linker flag CTF_LINK_NO_FILTER_REPORTED_SYMS that is set to stop the linker filtering the symbols in the symtypetab sections using the set that the linker has reported: use the presence or absence of this flag to determine whether to emit unindexed symtabs: we only remove entries from the variable section when filtering symbols, and we only remove them if they are in the reported symbol set, fixing the case where no symbols are reported by the linker at all. (The negative sense of the new CTF_LINK flag is intentional: the common case, both for ld and for simple tools that want to do a ctf_link with no ELF symbol table in sight, is probably to filter out symbols that no linker has reported: i.e., for the simple tools, all of them.) There's another wrinkle, though. It is quite possible for a non-linker to add symbols to a dict via ctf_add__sym and then write it out via the ctf_write APIs: perhaps it's preparing a dict for a later linker invocation. Right now this would not lead to anything terribly meaningful happening: ctf_serialize just assumes it was called via ctf_link if symbols are present. So add an (internal-to-libctf) flag that indicates that a writeout is happening via ctf_link_write, and set it there (propagating it to child dicts as needed). ctf_serialize can then spot when it is not being called by a linker, and arrange to always write out an indexed, sorted symtypetab for fastest possible future symbol lookup by name in that case. (The writeouts done by ld -r are unsorted, because the only thing likely to use those symtabs is the linker, which doesn't benefit from symtypetab sorting.) Tests added for all three linking cases (ld -r, ld -shared, ld), with a bit of testsuite framework enhancement to stop it unconditionally linking the CTF to be checked by the lookup program with -shared, so tests can now examine CTF linked with -r or indeed with no flags at all, though the output filename is still foo.so even in this case. Another test added for the non-linker case that endeavours to determine whether the symtypetab is sorted by examining the order of entries returned from ctf_symbol_next: nobody outside libctf should rely on this ordering, but this test is not outside libctf :) include/ChangeLog 2021-01-26 Nick Alcock <nick.alcock@oracle.com> ctf-api.h (CTF_LINK_NO_FILTER_REPORTED_SYMS): New. ld/ChangeLog 2021-01-26 Nick Alcock <nick.alcock@oracle.com> * ldlang.c (lang_merge_ctf): Set CTF_LINK_NO_FILTER_REPORTED_SYMS when appropriate. libctf/ChangeLog 2021-01-27 Nick Alcock <nick.alcock@oracle.com> * ctf-impl.c (_libctf_nonnull_): Add parameters. (LCTF_LINKING): New flag. (ctf_dict_t) <ctf_link_flags>: Mention it. * ctf-link.c (ctf_link): Keep LCTF_LINKING set across call. (ctf_write): Likewise, including in child dictionaries. (ctf_link_shuffle_syms): Make sure ctf_dynsyms is NULL if there are no reported symbols. * ctf-create.c (symtypetab_delete_nonstatic_vars): Make sure the variable has been reported as a symbol by the linker. (symtypetab_skippable): Mention relationship between SYMFP and the flags. (symtypetab_density): Adjust nonnullity. Exit early if no symbols were reported and force-indexing is off (i.e., we are doing a final link). (ctf_serialize): Handle the !LCTF_LINKING case by writing out an indexed, sorted symtypetab (and allow SYMFP to be NULL in this case). Turn sorting off if this is a non-final link. Only delete nonstatic vars if we are filtering symbols and the linker has reported some. * testsuite/libctf-regression/nonstatic-var-section-ld-r: New test of variable and symtypetab section population when ld -r is used. testsuite/libctf-regression/nonstatic-var-section-ld-executable.lk: Likewise, when ld of an executable is used. * testsuite/libctf-regression/nonstatic-var-section-ld.lk: Likewise, when ld -shared alone is used. * testsuite/libctf-regression/nonstatic-var-section-ld.c: Lookup programs for the above. testsuite/libctf-writable/symtypetab-nonlinker-writeout.: New test, testing survival of symbols across ctf_write paths. testsuite/lib/ctf-lib.exp (run_lookup_test): New option, nonshared, suppressing linking of the SOURCE with -shared.	5 years ago
Nick Alcock	6c3a38777b	libctf, include: support unnamed structure members better libctf has no intrinsic support for the GCC unnamed structure member extension. This principally means that you can't look up named members inside unnamed struct or union members via ctf_member_info: you have to tiresomely find out the type ID of the unnamed members via iteration, then look in each of these. This is ridiculous. Fix it by extending ctf_member_info so that it recurses into unnamed members for you: this is still unambiguous because GCC won't let you create ambiguously-named members even in the presence of this extension. For consistency, and because the release hasn't happened and we can still do this, break the ctf_member_next API and add flags: we specify one flag, CTF_MN_RECURSE, which if set causes ctf_member_next to automatically recurse into unnamed members for you, returning not only the members themselves but all their contained members, so that you can use ctf_member_next to identify every member that it would be valid to call ctf_member_info with. New lookup tests are added for all of this. include/ChangeLog 2021-01-05 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (CTF_MN_RECURSE): New. (ctf_member_next): Add flags argument. libctf/ChangeLog 2021-01-05 Nick Alcock <nick.alcock@oracle.com> * ctf-impl.h (struct ctf_next) <u.ctn_next>: Move to... <ctn_next>: ... here. * ctf-util.c (ctf_next_destroy): Unconditionally destroy it. * ctf-lookup.c (ctf_symbol_next): Adjust accordingly. * ctf-types.c (ctf_member_iter): Reimplement in terms of... (ctf_member_next): ... this. Support recursive unnamed member iteration (off by default). (ctf_member_info): Look up members in unnamed sub-structs. * ctf-dedup.c (ctf_dedup_rhash_type): Adjust ctf_member_next call. (ctf_dedup_emit_struct_members): Likewise. * testsuite/libctf-lookup/struct-iteration-ctf.c: Test empty unnamed members, and a normal member after the end. * testsuite/libctf-lookup/struct-iteration.c: Verify that ctf_member_count is consistent with the number of successful returns from a non-recursive ctf_member_next. * testsuite/libctf-lookup/struct-iteration-: New, test iteration over struct members. testsuite/libctf-lookup/struct-lookup.c: New test. * testsuite/libctf-lookup/struct-lookup.lk: New test.	5 years ago
Nick Alcock	ffeece6ac2	libctf, ld: prohibit getting the size or alignment of forwards C allows you to do only a very few things with entities of incomplete type (as opposed to pointers to them): make pointers to them and give them cv-quals, roughly. In particular you can't sizeof them and you can't get their alignment. We cannot impose all the requirements the standard imposes on CTF users, because the deduplicator can transform any structure type into a forward for the purposes of breaking cycles: so CTF type graphs can easily contain things like arrays of forward type (if you want to figure out their size or alignment, you need to chase down the types this forward might be a forward to in child TU dicts: we will soon add API functions to make doing this much easier). Nonetheless, it is still meaningless to ask for the size or alignment of forwards: but libctf didn't prohibit this and returned nonsense from internal implementation details when you asked (it returned the kind of the pointed-to type as both the size and alignment, because forwards reuse ctt_type as a type kind, and ctt_type and ctt_size overlap). So introduce a new error, ECTF_INCOMPLETE, which is returned when you try to get the size or alignment of forwards: we also return it when you try to do things that require libctf itself to get the size or alignment of a forward, notably using a forward as an array index type (which C should never do in any case) or adding forwards to structures without specifying their offset explicitly. The dumper will not emit size or alignment info for forwards any more. (This should not be an API break since ctf_type_size and ctf_type_align could both return errors before now: any code that isn't expecting error returns is already potentially broken.) include/ChangeLog 2021-01-05 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ECTF_INCOMPLETE): New. (ECTF_NERR): Adjust. ld/ChangeLog 2021-01-05 Nick Alcock <nick.alcock@oracle.com> * testsuite/ld-ctf/conflicting-cycle-1.parent.d: Adjust for dumper changes. * testsuite/ld-ctf/cross-tu-cyclic-conflicting.d: Likewise. * testsuite/ld-ctf/forward.c: New test... * testsuite/ld-ctf/forward.d: ... and results. libctf/ChangeLog 2021-01-05 Nick Alcock <nick.alcock@oracle.com> * ctf-types.c (ctf_type_resolve): Improve comment. (ctf_type_size): Yield ECTF_INCOMPLETE when applied to forwards. Emit errors into the right dict. (ctf_type_align): Likewise. * ctf-create.c (ctf_add_member_offset): Yield ECTF_INCOMPLETE when adding a member without explicit offset when this member, or the previous member, is incomplete. * ctf-dump.c (ctf_dump_format_type): Do not try to print the size of forwards. (ctf_dump_member): Do not try to print their alignment.	5 years ago
Alan Modra	250d07de5c	Update year range in copyright notice of binutils files	5 years ago
Nick Alcock	53651de80f	libctf, include: support foreign-endianness symtabs with CTF The CTF symbol lookup machinery added recently has one deficit: it assumes the symtab is in the machine's native endianness. This is always true when the linker is writing out symtabs (because cross linkers byteswap symbols only after libctf has been called on them), but may be untrue in the cross case when the linker or another tool (objdump, etc) is reading them. Unfortunately the easy way to model this to the caller, as an endianness field in the ctf_sect_t, is precluded because doing so would change the size of the ctf_sect_t, which would be an ABI break. So, instead, allow the endianness of the symtab to be set after open time, by calling one of the two new API functions ctf_symsect_endianness (for ctf_dict_t's) or ctf_arc_symsect_endianness (for entire ctf_archive_t's). libctf calls these functions automatically for objects opened via any of the BFD-aware mechanisms (ctf_bfdopen, ctf_bfdopen_ctfsect, ctf_fdopen, ctf_open, or ctf_arc_open), but the various mechanisms that just take raw ctf_sect_t's will assume the symtab is in native endianness and need a later call to ctf_symsect_endianness to adjust it if needed. (This call is basically free if the endianness is actually native: it only costs anything if the symtab endianness was previously guessed wrong, and there is a symtab, and we are using it directly rather than using symtab indexing.) Obviously, calling ctf_lookup_by_symbol or ctf_symbol_next before the symtab endianness is correctly set will probably give wrong answers -- but you can set it at any time as long as it is before then. include/ChangeLog 2020-11-23 Nick Alcock <nick.alcock@oracle.com> ctf-api.h: Style nit: remove () on function names in comments. (ctf_sect_t): Mention endianness concerns. (ctf_symsect_endianness): New declaration. (ctf_arc_symsect_endianness): Likewise. libctf/ChangeLog 2020-11-23 Nick Alcock <nick.alcock@oracle.com> * ctf-impl.h (ctf_dict_t) <ctf_symtab_little_endian>: New. (struct ctf_archive_internal) <ctfi_symsect_little_endian>: Likewise. * ctf-create.c (ctf_serialize): Adjust for new field. * ctf-open.c (init_symtab): Note the semantics of repeated calls. (ctf_symsect_endianness): New. (ctf_bufopen_internal): Set ctf_symtab_little_endian suitably for the native endianness. (_Static_assert): Moved... (swap_thing): ... with this... * swap.h: ... to here. * ctf-util.c (ctf_elf32_to_link_sym): Use it, byteswapping the Elf32_Sym if the ctf_symtab_little_endian demands it. (ctf_elf64_to_link_sym): Likewise swap the Elf64_Sym if needed. * ctf-archive.c (ctf_arc_symsect_endianness): New, set the endianness of the symtab used by the dicts in an archive. (ctf_archive_iter_internal): Initialize to unknown (assumed native, do not call ctf_symsect_endianness). (ctf_dict_open_by_offset): Call ctf_symsect_endianness if need be. (ctf_dict_open_internal): Propagate the endianness down. (ctf_dict_open_sections): Likewise. * ctf-open-bfd.c (ctf_bfdopen_ctfsect): Get the endianness from the struct bfd and pass it down to the archive. * libctf.ver: Add ctf_symsect_endianness and ctf_arc_symsect_endianness.	5 years ago
Nick Alcock	97a2a623d0	libctf, include: add ctf_getsymsect and ctf_getstrsect libctf has long provided ctf_getdatasect, which hands back a pointer to the CTF section a (read-only) dict came from. But it has no such functions to return pointers to the ELF symbol table or string table it's working from, which is unfortunate because several libctf functions (ctf_open, ctf_fdopen, and ctf_bfdopen) figure out which string and symbol table to use themselves, and don't tell the user what they decided, so the caller can't agree on which symtab to use with libctf even if it wanted to. Add a pair of functions to return the symtab and strtab in use. Like ctf_getdatasect, these return ctf_sect_t structures by value, filled with all-NULL/0 content if a symtab or strtab is not being used. include/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ctf_getsymsect): New. (ctf_getstrsect): Likewise. libctf/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-open.c (ctf_getsymsect): New. (ctf_getstrsect): Likewise. * libctf.ver: Add them.	5 years ago
Nick Alcock	2c78e92523	libctf, include: CTF-archive-wide symbol lookup CTF archives may contain multiple dicts, each of which contain many types and possibly a bunch of symtypetab entries relating to those types: each symtypetab entry is going to appear in exactly one dict, with the corresponding entries in the other dicts empty (either pads, or indexed symtypetabs that do not mention that symbol). But users of libctf usually want to get back the type associated with a symbol without having to dig around to find out which dict that type might be in. This adds machinery to do that -- and since you probably want to do it repeatedly, it adds internal caching to the ctf-archive machinery so that iteration over archives via ctf_archive_next and repeated symbol lookups do not have to repeatedly reopen the archive. (Iteration using ctf_archive_iter will gain caching soon.) Two new API functions: ctf_dict_t * ctf_arc_lookup_symbol (ctf_archive_t arc, unsigned long symidx, ctf_id_t typep, int errp); This looks up the symbol with index SYMIDX in the archive ARC, returning the dictionary in which it resides and optionally the type index as well. Errors are returned in ERRP. The dict should be ctf_dict_close()d when done, but is also cached inside the ctf_archive so that the open cost is only paid once. The result of the symbol lookup is also cached internally, so repeated lookups of the same symbol are nearly free. void ctf_arc_flush_caches (ctf_archive_t arc); Flush all the caches. Done at close time, but also available as an API function if users want to do it by hand. include/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ctf_arc_lookup_symbol): New. (ctf_arc_flush_caches): Likewise. * ctf.h: Document new auto-ctf_import behaviour. libctf/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-impl.h (struct ctf_archive_internal) <ctfi_dicts>: New, dicts the archive machinery has opened and cached. <ctfi_symdicts>: New, cache of dicts containing symbols looked up. <ctfi_syms>: New, cache of types of symbols looked up. * ctf-archive.c (ctf_arc_close): Free them on close. (enosym): New, flag entry for 'symbol not present'. (ctf_arc_import_parent): New, automatically import the parent from ".ctf" if this is a child in an archive and ".ctf" is present. (ctf_dict_open_sections): Use it. (ctf_archive_iter_internal): Likewise. (ctf_cached_dict_close): New, thunk around ctf_dict_close. (ctf_dict_open_cached): New, open and cache a dict. (ctf_arc_flush_caches): New, flush the caches. (ctf_arc_lookup_symbol): New, look up a symbol in (all members of) an archive, and cache the lookup. (ctf_archive_iter): Note the new caching behaviour. (ctf_archive_next): Use ctf_dict_open_cached. * libctf.ver: Add ctf_arc_lookup_symbol and ctf_arc_flush_caches.	5 years ago
Nick Alcock	1136c37971	libctf: symbol type linking support This adds facilities to write out the function info and data object sections, which efficiently map from entries in the symbol table to types. The write-side code is entirely new: the read-side code was merely significantly changed and support for indexed tables added (pointed to by the no-longer-unused cth_objtidxoff and cth_funcidxoff header fields). With this in place, you can use ctf_lookup_by_symbol to look up the types of symbols of function and object type (and, as before, you can use ctf_lookup_variable to look up types of file-scope variables not present in the symbol table, as long as you know their name: but variables that are also data objects are now found in the data object section instead.) (Compatible) file format change: The CTF spec has always said that the function info section looks much like the CTF_K_FUNCTIONs in the type section: an info word (including an argument count) followed by a return type and N argument types. This format is suboptimal: it means function symbols cannot be deduplicated and it causes a lot of ugly code duplication in libctf. But conveniently the compiler has never emitted this! Because it has always emitted a rather different format that libctf has never accepted, we can be sure that there are no instances of this function info section in the wild, and can freely change its format without compatibility concerns or a file format version bump. (And since it has never been emitted in any code that generated any older file format version, either, we need keep no code to read the format as specified at all!) So the function info section is now specified as an array of uint32_t, exactly like the object data section: each entry is a type ID in the type section which must be of kind CTF_K_FUNCTION, the prototype of this function. This allows function types to be deduplicated and also correctly encodes the fact that all functions declared in C really are types available to the program: so they should be stored in the type section like all other types. (In format v4, we will be able to represent the types of static functions as well, but that really does require a file format change.) We introduce a new header flag, CTF_F_NEWFUNCINFO, which is set if the new function info format is in use. A sufficiently new compiler will always set this flag. New libctf will always set this flag: old libctf will refuse to open any CTF dicts that have this flag set. If the flag is not set on a dict being read in, new libctf will disregard the function info section. Format v4 will remove this flag (or, rather, the flag has no meaning there and the bit position may be recycled for some other purpose). New API: Symbol addition: ctf_add_func_sym: Add a symbol with a given name and type. The type must be of kind CTF_K_FUNCTION (a function pointer). Internally this adds a name -> type mapping to the ctf_funchash in the ctf_dict. ctf_add_objt_sym: Add a symbol with a given name and type. The type kind can be anything, including function pointers. This adds to ctf_objthash. These both treat symbols as name -> type mappings: the linker associates symbol names with symbol indexes via the ctf_link_shuffle_syms callback, which sets up the ctf_dynsyms/ctf_dynsymidx/ctf_dynsymmax fields in the ctf_dict. Repeated relinks can add more symbols. Variables that are also exposed as symbols are removed from the variable section at serialization time. CTF symbol type sections which have enough pads, defined by CTF_INDEX_PAD_THRESHOLD (whether because they are in dicts with symbols where most types are unknown, or in archive where most types are defined in some child or parent dict, not in this specific dict) are sorted by name rather than symidx and accompanied by an index which associates each symbol type entry with a name: the existing ctf_lookup_by_symbol will map symbol indexes to symbol names and look the names up in the index automatically. (This is currently ELF-symbol-table-dependent, but there is almost nothing specific to ELF in here and we can add support for other symbol table formats easily). The compiler also uses index sections to communicate the contents of object file symbol tables without relying on any specific ordering of symbols: it doesn't need to sort them, and libctf will detect an unsorted index section via the absence of the new CTF_F_IDXSORTED header flag, and sort it if needed. Iteration: ctf_symbol_next: Iterator which returns the types and names of symbols one by one, either for function or data symbols. This does not require any sorting: the ctf_link machinery uses it to pull in all the compiler-provided symbols cheaply, but it is not restricted to that use. (Compatible) changes in API: ctf_lookup_by_symbol: can now be called for object and function symbols: never returns ECTF_NOTDATA (which is now not thrown by anything, but is kept for compatibility and because it is a plausible error that we might start throwing again at some later date). Internally we also have changes to the ctf-string functionality so that "external" strings (those where we track a string -> offset mapping, but only write out an offset) can be consulted via the usual means (ctf_strptr) before the strtab is written out. This is important because ctf_link_add_linker_symbol can now be handed symbols named via strtab offsets, and ctf_link_shuffle_syms must figure out their actual names by looking in the external symtab we have just been fed by the ctf_link_add_strtab callback, long before that strtab is written out. include/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ctf_symbol_next): New. (ctf_add_objt_sym): Likewise. (ctf_add_func_sym): Likewise. * ctf.h: Document new function info section format. (CTF_F_NEWFUNCINFO): New. (CTF_F_IDXSORTED): New. (CTF_F_MAX): Adjust accordingly. libctf/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-impl.h (CTF_INDEX_PAD_THRESHOLD): New. (_libctf_nonnull_): Likewise. (ctf_in_flight_dynsym_t): New. (ctf_dict_t) <ctf_funcidx_names>: Likewise. <ctf_objtidx_names>: Likewise. <ctf_nfuncidx>: Likewise. <ctf_nobjtidx>: Likewise. <ctf_funcidx_sxlate>: Likewise. <ctf_objtidx_sxlate>: Likewise. <ctf_objthash>: Likewise. <ctf_funchash>: Likewise. <ctf_dynsyms>: Likewise. <ctf_dynsymidx>: Likewise. <ctf_dynsymmax>: Likewise. <ctf_in_flight_dynsym>: Likewise. (struct ctf_next) <u.ctn_next>: Likewise. (ctf_symtab_skippable): New prototype. (ctf_add_funcobjt_sym): Likewise. (ctf_dynhash_sort_by_name): Likewise. (ctf_sym_to_elf64): Rename to... (ctf_elf32_to_link_sym): ... this, and... (ctf_elf64_to_link_sym): ... this. * ctf-open.c (init_symtab): Check for lack of CTF_F_NEWFUNCINFO flag, and presence of index sections. Refactor out ctf_symtab_skippable and ctf_elf_to_link_sym, and use them. Use ctf_link_sym_t, not Elf64_Sym. Skip initializing objt or func sxlate sections if corresponding index section is present. Adjust for new func info section format. (ctf_bufopen_internal): Add ctf_err_warn to corrupt-file error handling. Report incorrect-length index sections. Always do an init_symtab, even if there is no symtab section (there may be index sections still). (flip_objts): Adjust comment: func and objt sections are actually identical in structure now, no need to caveat. (ctf_dict_close): Free newly-added data structures. ctf-create.c (ctf_create): Initialize them. (ctf_symtab_skippable): New, refactored out of init_symtab, with st_nameidx_set check added. (ctf_add_funcobjt_sym): New, add a function or object symbol to the ctf_objthash or ctf_funchash, by name. (ctf_add_objt_sym): Call it. (ctf_add_func_sym): Likewise. (symtypetab_delete_nonstatic_vars): New, delete vars also present as data objects. (CTF_SYMTYPETAB_EMIT_FUNCTION): New flag to symtypetab emitters: this is a function emission, not a data object emission. (CTF_SYMTYPETAB_EMIT_PAD): New flag to symtypetab emitters: emit pads for symbols with no type (only set for unindexed sections). (CTF_SYMTYPETAB_FORCE_INDEXED): New flag to symtypetab emitters: always emit indexed. (symtypetab_density): New, figure out section sizes. (emit_symtypetab): New, emit a symtypetab. (emit_symtypetab_index): New, emit a symtypetab index. (ctf_serialize): Call them, emitting suitably sorted symtypetab sections and indexes. Set suitable header flags. Copy over new fields. * ctf-hash.c (ctf_dynhash_sort_by_name): New, used to impose an order on symtypetab index sections. * ctf-link.c (ctf_add_type_mapping): Delete erroneous comment relating to code that was never committed. (ctf_link_one_variable): Improve variable name. (check_sym): New, symtypetab analogue of check_variable. (ctf_link_deduplicating_one_symtypetab): New. (ctf_link_deduplicating_syms): Likewise. (ctf_link_deduplicating): Call them. (ctf_link_deduplicating_per_cu): Note that we don't call them in this case (yet). (ctf_link_add_strtab): Set the error on the fp correctly. (ctf_link_add_linker_symbol): New (no longer a do-nothing stub), add a linker symbol to the in-flight list. (ctf_link_shuffle_syms): New (no longer a do-nothing stub), turn the in-flight list into a mapping we can use, now its names are resolvable in the external strtab. * ctf-string.c (ctf_str_rollback_atom): Don't roll back atoms with external strtab offsets. (ctf_str_rollback): Adjust comment. (ctf_str_write_strtab): Migrate ctf_syn_ext_strtab population from writeout time... (ctf_str_add_external): ... to string addition time. * ctf-lookup.c (ctf_lookup_var_key_t): Rename to... (ctf_lookup_idx_key_t): ... this, now we use it for syms too. <clik_names>: New member, a name table. (ctf_lookup_var): Adjust accordingly. (ctf_lookup_variable): Likewise. (ctf_lookup_by_id): Shuffle further up in the file. (ctf_symidx_sort_arg_cb): New, callback for... (sort_symidx_by_name): ... this new function to sort a symidx found to be unsorted (likely originating from the compiler). (ctf_symidx_sort): New, sort a symidx. (ctf_lookup_symbol_name): Support dynamic symbols with indexes provided by the linker. Use ctf_link_sym_t, not Elf64_Sym. Check the parent if a child lookup fails. (ctf_lookup_by_symbol): Likewise. Work for function symbols too. (ctf_symbol_next): New, iterate over symbols with types (without sorting). (ctf_lookup_idx_name): New, bsearch for symbol names in indexes. (ctf_try_lookup_indexed): New, attempt an indexed lookup. (ctf_func_info): Reimplement in terms of ctf_lookup_by_symbol. (ctf_func_args): Likewise. (ctf_get_dict): Move... * ctf-types.c (ctf_get_dict): ... here. * ctf-util.c (ctf_sym_to_elf64): Re-express as... (ctf_elf64_to_link_sym): ... this. Add new st_symidx field, and st_nameidx_set (always 0, so st_nameidx can be ignored). Look in the ELF strtab for names. (ctf_elf32_to_link_sym): Likewise, for Elf32_Sym. (ctf_next_destroy): Destroy ctf_next_t.u.ctn_next if need be. * libctf.ver: Add ctf_symbol_next, ctf_add_objt_sym and ctf_add_func_sym.	5 years ago
Nick Alcock	3d16b64e28	bfd, include, ld, binutils, libctf: CTF should use the dynstr/sym This is embarrassing. The whole point of CTF is that it remains intact even after a binary is stripped, providing a compact mapping from symbols to types for everything in the externally-visible interface of an ELF object: it has connections to the symbol table for that purpose, and to the string table to avoid duplicating symbol names. So it's a shame that the hooks I implemented last year served to hook it up to the .symtab and .strtab, which obviously disappear on strip, leaving any accompanying the CTF dict containing references to strings (and, soon, symbols) which don't exist any more because their containing strtab has been vaporized. The original Solaris design used .dynsym and .dynstr (well, actually, .ldynsym, which has more symbols) which do not disappear. So should we. Thankfully the work we did before serves as guide rails, and adjusting things to use the .dynstr and .dynsym was fast and easy. The only annoyance is that the dynsym is assembled inside elflink.c in a fairly piecemeal fashion, so that the easiest way to get the symbols out was to hook in before every call to swap_symbol_out (we also leave in a hook in front of symbol additions to the .symtab because it seems plausible that we might want to hook them in future too: for now that hook is unused). We adjust things so that rather than being offered a whole hash table of symbols at once, libctf is now given symbols one at a time, with st_name indexes already resolved and pointing at their final .dynstr offsets: it's now up to libctf to resolve these to names as needed using the strtab info we pass it separately. Some bits might be contentious. The ctf_new_dynstr callback takes an elf_internal_sym, and this remains an elf_internal_sym right down through the generic emulation layers into ldelfgen. This is no worse than the elf_sym_strtab we used to pass down, but in the future when we gain non-ELF CTF symtab support we might want to lower the elf_internal_sym to some other representation (perhaps a ctf_link_symbol) in bfd or in ldlang_ctf_new_dynsym. We rename the 'apply_strsym' hooks to 'acquire_strings' instead, becuse they no longer have anything to do with symbols. There are some API changes to pieces of API which are technically public but actually totally unused by anything and/or unused by anything but ld so they can change freely: the ctf_link_symbol gains new fields to allow symbol names to be given as strtab offsets as well as strings, and a symidx so that the symbol index can be passed in. ctf_link_shuffle_syms loses its callback parameter: the idea now is that linkers call the new ctf_link_add_linker_symbol for every symbol in .dynsym, feed in all the strtab entries with ctf_link_add_strtab, and then a call to ctf_link_shuffle_syms will apply both and arrange to use them to reorder the CTF symtab at CTF serialization time (which is coming in the next commit). Inside libctf we have a new preamble flag CTF_F_DYNSTR which is always set in v3-format CTF dicts from this commit forwards: CTF dicts without this flag are associated with .strtab like they used to be, so that old dicts' external strings don't turn to garbage when loaded by new libctf. Dicts with this flag are associated with .dynstr and .dynsym instead. (The flag is not the next in sequence because this commit was written quite late: the missing flags will be filled in by the next commit.) Tests forthcoming in a later commit in this series. bfd/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * elflink.c (elf_finalize_dynstr): Call examine_strtab after dynstr finalization. (elf_link_swap_symbols_out): Don't call it here. Call ctf_new_symbol before swap_symbol_out. (elf_link_output_extsym): Call ctf_new_dynsym before swap_symbol_out. (bfd_elf_final_link): Likewise. * elf.c (swap_out_syms): Pass in bfd_link_info. Call ctf_new_symbol before swap_symbol_out. (_bfd_elf_compute_section_file_positions): Adjust. binutils/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * readelf.c (dump_section_as_ctf): Use .dynsym and .dynstr, not .symtab and .strtab. include/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * bfdlink.h (struct elf_sym_strtab): Replace with... (struct elf_internal_sym): ... this. (struct bfd_link_callbacks) <examine_strtab>: Take only a symstrtab argument. <ctf_new_symbol>: New. <ctf_new_dynsym>: Likewise. * ctf-api.h (struct ctf_link_sym) <st_symidx>: New. <st_nameidx>: Likewise. <st_nameidx_set>: Likewise. (ctf_link_iter_symbol_f): Removed. (ctf_link_shuffle_syms): Remove most parameters, just takes a ctf_dict_t now. (ctf_link_add_linker_symbol): New, split from ctf_link_shuffle_syms. * ctf.h (CTF_F_DYNSTR): New. (CTF_F_MAX): Adjust. ld/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ldelfgen.c (struct ctf_strsym_iter_cb_arg): Rename to... (struct ctf_strtab_iter_cb_arg): ... this, changing fields: <syms>: Remove. <symcount>: Remove. <symstrtab>: Rename to... <strtab>: ... this. (ldelf_ctf_strtab_iter_cb): Adjust. (ldelf_ctf_symbols_iter_cb): Remove. (ldelf_new_dynsym_for_ctf): New, tell libctf about a single symbol. (ldelf_examine_strtab_for_ctf): Rename to... (ldelf_acquire_strings_for_ctf): ... this, only doing the strtab portion and not symbols. * ldelfgen.h: Adjust declarations accordingly. * ldemul.c (ldemul_examine_strtab_for_ctf): Rename to... (ldemul_acquire_strings_for_ctf): ... this. (ldemul_new_dynsym_for_ctf): New. * ldemul.h: Adjust declarations accordingly. * ldlang.c (ldlang_ctf_apply_strsym): Rename to... (ldlang_ctf_acquire_strings): ... this. (ldlang_ctf_new_dynsym): New. (lang_write_ctf): Call ldemul_new_dynsym_for_ctf with NULL to do the actual symbol shuffle. * ldlang.h (struct elf_strtab_hash): Adjust accordingly. * ldmain.c (bfd_link_callbacks): Wire up new/renamed callbacks. libctf/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-link.c (ctf_link_shuffle_syms): Adjust. (ctf_link_add_linker_symbol): New, unimplemented stub. * libctf.ver: Add it. * ctf-create.c (ctf_serialize): Set CTF_F_DYNSTR on newly-serialized dicts. * ctf-open-bfd.c (ctf_bfdopen_ctfsect): Check for the flag: open the symtab/strtab if not present, dynsym/dynstr otherwise. * ctf-archive.c (ctf_arc_bufpreamble): New, get the preamble from some arbitrary member of a CTF archive. * ctf-impl.h (ctf_arc_bufpreamble): Declare it.	5 years ago
Nick Alcock	ae41200ba8	libctf, include, binutils, gdb: rename CTF-opening functions The functions that return ctf_dict_t's given a ctf_archive_t and a name are very clumsily named. It sounds like they return archives, not dictionaries, and the names are very long and clunky. Why do we have a ctf_arc_open_by_name when it opens a dictionary, not an archive, and when there is no way to open a dictionary in any other way? The answer is purely internal: the function is located in ctf-archive.c, and everything in there was called ctf_arc_, and there is another way to open a dict (by offset in the archive), that is internal to ctf-archive.c and that nothing else can call. This is clearly bad naming. The internal organization of the source tree should not dictate public API names! So rename things (keeping the old, bad names for compatibility), and adjust all users. You now open a dict using ctf_dict_open, and open it giving ELF sections via ctf_dict_open_sections. binutils/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> objdump.c (dump_ctf): Use ctf_dict_open, not ctf_arc_open_by_name. * readelf.c (dump_section_as_ctf): Likewise. gdb/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctfread.c (elfctf_build_psymtabs): Use ctf_dict_open, not ctf_arc_open_by_name. include/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ctf_arc_open_by_name): Rename to... (ctf_dict_open): ... this, keeping compatibility function. (ctf_arc_open_by_name_sections): Rename to... (ctf_dict_open_sections): ... this, keeping compatibility function. libctf/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-archive.c (ctf_arc_open_by_offset): Rename to... (ctf_dict_open_by_offset): ... this. Adjust callers. (ctf_arc_open_by_name_internal): Rename to... (ctf_dict_open_internal): ... this. Adjust callers. (ctf_arc_open_by_name_sections): Rename to... (ctf_dict_open_sections): ... this, keeping compatibility function. (ctf_arc_open_by_name): Rename to... (ctf_dict_open): ... this, keeping compatibility function. * libctf.ver: New functions added. * ctf-link.c (ctf_link_one_input_archive): Adjusted accordingly. (ctf_link_deduplicating_open_inputs): Likewise.	5 years ago
Nick Alcock	139633c307	libctf, include, binutils, gdb, ld: rename ctf_file_t to ctf_dict_t The naming of the ctf_file_t type in libctf is a historical curiosity. Back in the Solaris days, CTF dictionaries were originally generated as a separate file and then (sometimes) merged into objects: hence the datatype was named ctf_file_t, and known as a "CTF file". Nowadays, raw CTF is essentially never written to a file on its own, and the datatype changed name to a "CTF dictionary" years ago. So the term "CTF file" refers to something that is never a file! This is at best confusing. The type has also historically been known as a 'CTF container", which is even more confusing now that we have CTF archives which are also a sort of container (they contain CTF dictionaries), but which are never referred to as containers in the source code. So fix this by completing the renaming, renaming ctf_file_t to ctf_dict_t throughout, and renaming those few functions that refer to CTF files by name (keeping compatibility aliases) to refer to dicts instead. Old users who still refer to ctf_file_t will see (harmless) pointer-compatibility warnings at compile time, but the ABI is unchanged (since C doesn't mangle names, and ctf_file_t was always an opaque type) and things will still compile fine as long as -Werror is not specified. All references to CTF containers and CTF files in the source code are fixed to refer to CTF dicts instead. Further (smaller) renamings of annoyingly-named functions to come, as part of the process of souping up queries across whole archives at once (needed for the function info and data object sections). binutils/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * objdump.c (dump_ctf_errs): Rename ctf_file_t to ctf_dict_t. (dump_ctf_archive_member): Likewise. (dump_ctf): Likewise. Use ctf_dict_close, not ctf_file_close. * readelf.c (dump_ctf_errs): Rename ctf_file_t to ctf_dict_t. (dump_ctf_archive_member): Likewise. (dump_section_as_ctf): Likewise. Use ctf_dict_close, not ctf_file_close. gdb/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctfread.c: Change uses of ctf_file_t to ctf_dict_t. (ctf_fp_info::~ctf_fp_info): Call ctf_dict_close, not ctf_file_close. include/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ctf_file_t): Rename to... (ctf_dict_t): ... this. Keep ctf_file_t around for compatibility. (struct ctf_file): Likewise rename to... (struct ctf_dict): ... this. (ctf_file_close): Rename to... (ctf_dict_close): ... this, keeping compatibility function. (ctf_parent_file): Rename to... (ctf_parent_dict): ... this, keeping compatibility function. All callers adjusted. * ctf.h: Rename references to ctf_file_t to ctf_dict_t. (struct ctf_archive) <ctfa_nfiles>: Rename to... <ctfa_ndicts>: ... this. ld/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ldlang.c (ctf_output): This is a ctf_dict_t now. (lang_ctf_errs_warnings): Rename ctf_file_t to ctf_dict_t. (ldlang_open_ctf): Adjust comment. (lang_merge_ctf): Use ctf_dict_close, not ctf_file_close. * ldelfgen.h (ldelf_examine_strtab_for_ctf): Rename ctf_file_t to ctf_dict_t. Change opaque declaration accordingly. * ldelfgen.c (ldelf_examine_strtab_for_ctf): Adjust. * ldemul.h (examine_strtab_for_ctf): Likewise. (ldemul_examine_strtab_for_ctf): Likewise. * ldeuml.c (ldemul_examine_strtab_for_ctf): Likewise. libctf/ChangeLog 2020-11-20 Nick Alcock <nick.alcock@oracle.com> * ctf-impl.h: Rename ctf_file_t to ctf_dict_t: all declarations adjusted. (ctf_fileops): Rename to... (ctf_dictops): ... this. (ctf_dedup_t) <cd_id_to_file_t>: Rename to... <cd_id_to_dict_t>: ... this. (ctf_file_t): Fix outdated comment. <ctf_fileops>: Rename to... <ctf_dictops>: ... this. (struct ctf_archive_internal) <ctfi_file>: Rename to... <ctfi_dict>: ... this. * ctf-archive.c: Rename ctf_file_t to ctf_dict_t. Rename ctf_archive.ctfa_nfiles to ctfa_ndicts. Rename ctf_file_close to ctf_dict_close. All users adjusted. * ctf-create.c: Likewise. Refer to CTF dicts, not CTF containers. (ctf_bundle_t) <ctb_file>: Rename to... <ctb_dict): ... this. * ctf-decl.c: Rename ctf_file_t to ctf_dict_t. * ctf-dedup.c: Likewise. Rename ctf_file_close to ctf_dict_close. Refer to CTF dicts, not CTF containers. * ctf-dump.c: Likewise. * ctf-error.c: Likewise. * ctf-hash.c: Likewise. * ctf-inlines.h: Likewise. * ctf-labels.c: Likewise. * ctf-link.c: Likewise. * ctf-lookup.c: Likewise. * ctf-open-bfd.c: Likewise. * ctf-string.c: Likewise. * ctf-subr.c: Likewise. * ctf-types.c: Likewise. * ctf-util.c: Likewise. * ctf-open.c: Likewise. (ctf_file_close): Rename to... (ctf_dict_close): ...this. (ctf_file_close): New trivial wrapper around ctf_dict_close, for compatibility. (ctf_parent_file): Rename to... (ctf_parent_dict): ... this. (ctf_parent_file): New trivial wrapper around ctf_parent_dict, for compatibility. * libctf.ver: Add ctf_dict_close and ctf_parent_dict.	5 years ago
Tom Tromey	0d01fbe64f	Remove libctf/mkerrors.sed This patch removes libctf/mkerrors.sed, replacing it with a macro in ctf-api.h. This simplifies the build and avoids possible unportable code in the sed script. 2020-10-21 Tom Tromey <tromey@adacore.com> * ctf-api.h (_CTF_ERRORS): New macro. libctf/ChangeLog 2020-10-21 Tom Tromey <tromey@adacore.com> * mkerrors.sed: Remove. * ctf-error.c (_CTF_FIRST): New define. (_CTF_ITEM): Define this, not _CTF_STR. (_ctf_errlist, _ctf_erridx): Use _CTF_ERRORS. (ERRSTRFIELD): Rewrite. (ERRSTRFIELD1): Remove. * Makefile.in: Rebuild. * Makefile.am (BUILT_SOURCES): Remove. (ctf-error.h): Remove.	6 years ago
Nick Alcock	926c9e7665	libctf, binutils, include, ld: gettextize and improve error handling This commit follows on from the earlier commit "libctf, ld, binutils: add textual error/warning reporting for libctf" and converts every error in libctf that was reported using ctf_dprintf to use ctf_err_warn instead, gettextizing them in the process, using N_() where necessary to avoid doing gettext calls unless an error message is actually generated, and rephrasing some error messages for ease of translation. This requires a slight change in the ctf_errwarning_next API: this API is public but has not been in a release yet, so can still change freely. The problem is that many errors are emitted at open time (whether opening of a CTF dict, or opening of a CTF archive): the former of these throws away its incompletely-initialized ctf_file_t rather than return it, and the latter has no ctf_file_t at all. So errors and warnings emitted at open time cannot be stored in the ctf_file_t, and have to go elsewhere. We put them in a static local in ctf-subr.c (which is not very thread-safe: a later commit will improve things here): ctf_err_warn with a NULL fp adds to this list, and the public interface ctf_errwarning_next with a NULL fp retrieves from it. We need a slight exception from the usual iterator rules in this case: with a NULL fp, there is nowhere to store the ECTF_NEXT_END "error" which signifies the end of iteration, so we add a new err parameter to ctf_errwarning_next which is used to report such iteration-related errors. (If an fp is provided -- i.e., if not reporting open errors -- this is optional, but even if it's optional it's still an API change. This is actually useful from a usability POV as well, since ctf_errwarning_next is usually called when there's been an error, so overwriting the error code with ECTF_NEXT_END is not very helpful! So, unusually, ctf_errwarning_next now uses the passed fp for its error code only if no errp pointer is passed in, and leaves it untouched otherwise.) ld, objdump and readelf are adapted to call ctf_errwarning_next with a NULL fp to report open errors where appropriate. The ctf_err_warn API also has to change, gaining a new error-number parameter which is used to add the error message corresponding to that error number into the debug stream when LIBCTF_DEBUG is enabled: changing this API is easy at this point since we are already touching all existing calls to gettextize them. We need this because the debug stream should contain the errno's message, but the error reported in the error/warning stream should not, because the caller will probably report it themselves at failure time regardless, and reporting it in every error message that leads up to it leads to a ridiculous chattering on failure, which is likely to end up as ridiculous chattering on stderr (trimmed a bit): CTF error: `ld/testsuite/ld-ctf/A.c (0): lookup failure for type 3: flags 1: The parent CTF dictionary is unavailable' CTF error: `ld/testsuite/ld-ctf/A.c (0): struct/union member type hashing error during type hashing for type 80000001, kind 6: The parent CTF dictionary is unavailable' CTF error: `deduplicating link variable emission failed for ld/testsuite/ld-ctf/A.c: The parent CTF dictionary is unavailable' ld/.libs/lt-ld-new: warning: CTF linking failed; output will have no CTF section: `The parent CTF dictionary is unavailable' We only need to be told that the parent CTF dictionary is unavailable once, not over and over again! errmsgs are still emitted on warning generation, because warnings do not usually lead to a failure propagated up to the caller and reported there. Debug-stream messages are not translated. If translation is turned on, there will be a mixture of English and translated messages in the debug stream, but rather that than burden the translators with debug-only output. binutils/ChangeLog 2020-08-27 Nick Alcock <nick.alcock@oracle.com> * objdump.c (dump_ctf_archive_member): Move error- reporting... (dump_ctf_errs): ... into this separate function. (dump_ctf): Call it on open errors. * readelf.c (dump_ctf_archive_member): Move error- reporting... (dump_ctf_errs): ... into this separate function. Support calls with NULL fp. Adjust for new err parameter to ctf_errwarning_next. (dump_section_as_ctf): Call it on open errors. include/ChangeLog 2020-08-27 Nick Alcock <nick.alcock@oracle.com> * ctf-api.h (ctf_errwarning_next): New err parameter. ld/ChangeLog 2020-08-27 Nick Alcock <nick.alcock@oracle.com> * ldlang.c (lang_ctf_errs_warnings): Support calls with NULL fp. Adjust for new err parameter to ctf_errwarning_next. Only check for assertion failures when fp is non-NULL. (ldlang_open_ctf): Call it on open errors. * testsuite/ld-ctf/ctf.exp: Always use the C locale to avoid breaking the diags tests. libctf/ChangeLog 2020-08-27 Nick Alcock <nick.alcock@oracle.com> * ctf-subr.c (open_errors): New list. (ctf_err_warn): Calls with NULL fp append to open_errors. Add err parameter, and use it to decorate the debug stream with errmsgs. (ctf_err_warn_to_open): Splice errors from a CTF dict into the open_errors. (ctf_errwarning_next): Calls with NULL fp report from open_errors. New err param to report iteration errors (including end-of-iteration) when fp is NULL. (ctf_assert_fail_internal): Adjust ctf_err_warn call for new err parameter: gettextize. * ctf-impl.h (ctfo_get_vbytes): Add ctf_file_t parameter. (LCTF_VBYTES): Adjust. (ctf_err_warn_to_open): New. (ctf_err_warn): Adjust. (ctf_bundle): Used in only one place: move... * ctf-create.c: ... here. (enumcmp): Use ctf_err_warn, not ctf_dprintf, passing the err number down as needed. Don't emit the errmsg. Gettextize. (membcmp): Likewise. (ctf_add_type_internal): Likewise. (ctf_write_mem): Likewise. (ctf_compress_write): Likewise. Report errors writing the header or body. (ctf_write): Likewise. * ctf-archive.c (ctf_arc_write_fd): Use ctf_err_warn, not ctf_dprintf, and gettextize, as above. (ctf_arc_write): Likewise. (ctf_arc_bufopen): Likewise. (ctf_arc_open_internal): Likewise. * ctf-labels.c (ctf_label_iter): Likewise. * ctf-open-bfd.c (ctf_bfdclose): Likewise. (ctf_bfdopen): Likewise. (ctf_bfdopen_ctfsect): Likewise. (ctf_fdopen): Likewise. * ctf-string.c (ctf_str_write_strtab): Likewise. * ctf-types.c (ctf_type_resolve): Likewise. * ctf-open.c (get_vbytes_common): Likewise. Pass down the ctf dict. (get_vbytes_v1): Pass down the ctf dict. (get_vbytes_v2): Likewise. (flip_ctf): Likewise. (flip_types): Likewise. Use ctf_err_warn, not ctf_dprintf, and gettextize, as above. (upgrade_types_v1): Adjust calls. (init_types): Use ctf_err_warn, not ctf_dprintf, as above. (ctf_bufopen_internal): Likewise. Adjust calls. Transplant errors emitted into individual dicts into the open errors if this turns out to be a failed open in the end. * ctf-dump.c (ctf_dump_format_type): Adjust ctf_err_warn for new err argument. Gettextize. Don't emit the errmsg. (ctf_dump_funcs): Likewise. Collapse err label into its only case. (ctf_dump_type): Likewise. * ctf-link.c (ctf_create_per_cu): Adjust ctf_err_warn for new err argument. Gettextize. Don't emit the errmsg. (ctf_link_one_type): Likewise. (ctf_link_lazy_open): Likewise. (ctf_link_one_input_archive): Likewise. (ctf_link_deduplicating_count_inputs): Likewise. (ctf_link_deduplicating_open_inputs): Likewise. (ctf_link_deduplicating_close_inputs): Likewise. (ctf_link_deduplicating): Likewise. (ctf_link): Likewise. (ctf_link_deduplicating_per_cu): Likewise. Add some missed ctf_set_errnos to obscure error cases. * ctf-dedup.c (ctf_dedup_rhash_type): Adjust ctf_err_warn for new err argument. Gettextize. Don't emit the errmsg. (ctf_dedup_populate_mappings): Likewise. (ctf_dedup_detect_name_ambiguity): Likewise. (ctf_dedup_init): Likewise. (ctf_dedup_multiple_input_dicts): Likewise. (ctf_dedup_conflictify_unshared): Likewise. (ctf_dedup): Likewise. (ctf_dedup_rwalk_one_output_mapping): Likewise. (ctf_dedup_id_to_target): Likewise. (ctf_dedup_emit_type): Likewise. (ctf_dedup_emit_struct_members): Likewise. (ctf_dedup_populate_type_mapping): Likewise. (ctf_dedup_populate_type_mappings): Likewise. (ctf_dedup_emit): Likewise. (ctf_dedup_hash_type): Likewise. Fix a bit of messed-up error status setting. (ctf_dedup_rwalk_one_output_mapping): Likewise. Don't hide unknown-type-kind messages (which signify file corruption).	6 years ago
Nick Alcock	662df3c3f1	libctf, link: tie in the deduplicating linker This fairly intricate commit connects up the CTF linker machinery (which operates in terms of ctf_archive_t's on ctf_link_inputs -> ctf_link_outputs) to the deduplicator (which operates in terms of arrays of ctf_file_t's, all the archives exploded). The nondeduplicating linker is retained, but is not called unless the CTF_LINK_NONDEDUP flag is passed in (which ld never does), or the environment variable LD_NO_CTF_DEDUP is set. Eventually, once we have confidence in the much-more-complex deduplicating linker, I hope the nondeduplicating linker can be removed. In brief, what this does is traverses each input archive in ctf_link_inputs, opening every member (if not already open) and tying child dicts to their parents, shoving them into an array and constructing a corresponding parents array that tells the deduplicator which dict is the parent of which child. We then call ctf_dedup and ctf_dedup_emit with that array of inputs, taking the outputs that result and putting them into ctf_link_outputs where the rest of the CTF linker expects to find them, then linking in the variables just as is done by the nondeduplicating linker. It also implements much of the CU-mapping side of things. The problem CU-mapping introduces is that if you map many input CUs into one output, this is saying that you want many translation units to produce at most one child dict if conflicting types are found in any of them. This means you can suddenly have multiple distinct types with the same name in the same dict, which libctf cannot really represent because it's not something you can do with C translation units. The deduplicator machinery already committed does as best it can with these, hiding types with conflicting names rather than making child dicts out of them: but we still need to call it. This is done similarly to the main link, taking the inputs (one CU output at a time), deduplicating them, taking the output and making it an input to the final link. Two (significant) optimizations are done: we share atoms tables between all these links and the final link (so e.g. all type hash values are shared, all decorated type names, etc); and any CU-mapped links with only one input (and no child dicts) doesn't need to do anything other than renaming the CU: the CU-mapped link phase can be skipped for it. Put together, large CU-mapped links can save 50% of their memory usage and about as much time (and the memory usage for CU-mapped links is significant, because all those output CUs have to have all their types stored in memory all at once). include/ * ctf-api.h (CTF_LINK_NONDEDUP): New, turn off the deduplicator. libctf/ * ctf-impl.h (ctf_list_splice): New. * ctf-util.h (ctf_list_splice): Likewise. * ctf-link.c (link_sort_inputs_cb_arg_t): Likewise. (ctf_link_sort_inputs): Likewise. (ctf_link_deduplicating_count_inputs): Likewise. (ctf_link_deduplicating_open_inputs): Likewise. (ctf_link_deduplicating_close_inputs): Likewise. (ctf_link_deduplicating_variables): Likewise. (ctf_link_deduplicating_per_cu): Likewise. (ctf_link_deduplicating): Likewise. (ctf_link): Call it.	6 years ago
Nick Alcock	e3e8411bec	libctf, link: add CTF_LINK_OMIT_VARIABLES_SECTION This flag (not used anywhere yet) causes the variables section to be omitted from the output CTF dict. include/ * ctf-api.h (CTF_LINK_OMIT_VARIABLES_SECTION): New. libctf/ * ctf-link.c (ctf_link_one_input_archive_member): Check CTF_LINK_OMIT_VARIABLES_SECTION.	6 years ago
Nick Alcock	0f0c11f7fc	libctf, dedup: add deduplicator This adds the core deduplicator that the ctf_link machinery calls (possibly repeatedly) to link the CTF sections: it takes an array of input ctf_file_t's and another array that indicates which entries in the input array are parents of which other entries, and returns an array of outputs. The first output is always the ctf_file_t on which ctf_link/ctf_dedup/etc was called: the other outputs are child dicts that have the first output as their parent. include/ * ctf-api.h (CTF_LINK_SHARE_DUPLICATED): No longer unimplemented. libctf/ * ctf-impl.h (ctf_type_id_key): New, the key in the cd_id_to_file_t. (ctf_dedup): New, core deduplicator state. (ctf_file_t) <ctf_dedup>: New. <ctf_dedup_atoms>: New. <ctf_dedup_atoms_alloc>: New. (ctf_hash_type_id_key): New prototype. (ctf_hash_eq_type_id_key): Likewise. (ctf_dedup_atoms_init): Likewise. * ctf-hash.c (ctf_hash_eq_type_id_key): New. (ctf_dedup_atoms_init): Likewise. * ctf-create.c (ctf_serialize): Adjusted. (ctf_add_encoded): No longer static. (ctf_add_reftype): Likewise. * ctf-open.c (ctf_file_close): Destroy the ctf_dedup_atoms_alloc. * ctf-dedup.c: New file. * ctf-decls.h [!HAVE_DECL_STPCPY]: Add prototype. * configure.ac: Check for stpcpy. * Makefile.am: Add it. * Makefile.in: Regenerate. * config.h.in: Regenerate. * configure: Regenerate.	6 years ago
Nick Alcock	6dd2819ffc	libctf, link: add the ability to filter out variables from the link The CTF variables section (containing variables that have no corresponding symtab entries) can cause the string table to get very voluminous if the names of variables are long. Some callers want to filter out particular variables they know they won't need. So add a "variable filter" callback that does that: it's passed the name of the variable and a corresponding ctf_file_t / ctf_id_t pair, and should return 1 to filter it out. ld doesn't use this machinery yet, but we could easily add it later if desired. (But see later for a commit that turns off CTF variable- section linking in ld entirely by default.) include/ * ctf-api.h (ctf_link_variable_filter_t): New. (ctf_link_set_variable_filter): Likewise. libctf/ * libctf.ver (ctf_link_set_variable_filter): Add. * ctf-impl.h (ctf_file_t) <ctf_link_variable_filter>: New. <ctf_link_variable_filter_arg>: Likewise. * ctf-create.c (ctf_serialize): Adjust. * ctf-link.c (ctf_link_set_variable_filter): New, set it. (ctf_link_one_variable): Call it if set.	6 years ago
Nick Alcock	5f54462c6a	libctf, link: redo cu-mapping handling Now a bunch of stuff that doesn't apply to ld or any normal use of libctf, piled into one commit so that it's easier to ignore. The cu-mapping machinery associates incoming compilation unit names with outgoing names of CTF dictionaries that should correspond to them, for non-gdb CTF consumers that would like to group multiple TUs into a single child dict if conflicting types are found in it (the existing use case is one kernel module, one child CTF dict, even if the kernel module is composed of multiple CUs). The upcoming deduplicator needs to track not only the mapping from incoming CU name to outgoing dict name, but the inverse mapping from outgoing dict name to incoming CU name, so it can work over every CTF dict we might see in the output and link into it. So rejig the ctf-link machinery to do that. Simultaneously (because they are closely associated and were written at the same time), we add a new CTF_LINK_EMPTY_CU_MAPPINGS flag to ctf_link, which tells the ctf_link machinery to create empty child dicts for each outgoing CU mapping even if no CUs that correspond to it exist in the link. This is a bit (OK, quite a lot) of a waste of space, but some existing consumers require it. (Nobody else should use it.) Its value is not consecutive with existing CTF_LINK flag values because we're about to add more flags that are conceptually closer to the existing ones than this one is. include/ * ctf-api.h (CTF_LINK_EMPTY_CU_MAPPINGS): New. libctf/ * ctf-impl.h (ctf_file_t): Improve comments. <ctf_link_cu_mapping>: Split into... <ctf_link_in_cu_mapping>: ... this... <ctf_link_out_cu_mapping>: ... and this. * ctf-create.c (ctf_serialize): Adjust. * ctf-open.c (ctf_file_close): Likewise. * ctf-link.c (ctf_create_per_cu): Look things up in the in_cu_mapping instead of the cu_mapping. (ctf_link_add_cu_mapping): The deduplicating link will define what happens if many FROMs share a TO. (ctf_link_add_cu_mapping): Create in_cu_mapping and out_cu_mapping. Do not create ctf_link_outputs here any more, or create per-CU dicts here: they are already created when needed. (ctf_link_one_variable): Log a debug message if we skip a variable due to its type being concealed in a CU-mapped link. (This is probably too common a case to make into a warning.) (ctf_link): Create empty per-CU dicts if requested.	6 years ago
Nick Alcock	8d2229ad1e	libctf, link: add lazy linking: clean up input members: err/warn cleanup This rather large and intertwined pile of changes does three things: First, it transitions from dprintf to ctf_err_warn for things the user might care about: this one file is the major impetus for the ctf_err_warn infrastructure, because things like file names are crucial in linker error messages, and errno values are utterly incapable of communicating them Second, it stabilizes the ctf_link APIs: you can now call ctf_link_add_ctf without a CTF argument (only a NAME), to lazily ctf_open the file with the given NAME when needed, and close it as soon as possible, to save memory. This is not an API change because a null CTF argument was prohibited before now. Since getting CTF directly from files uses ctf_open, passing in only a NAME requires use of libctf, not libctf-nobfd. The linker's behaviour is unchanged, as it still passes in a ctf_archive_t as before. This also let us fix a leak: we were opening ctf_archives and their containing ctf_files, then only closing the files and leaving the archives open. Third, this commit restructures the ctf_link_in_member argument used by the CTF linking machinery and adjusts its users accordingly. We drop two members: - arcname, which is difficult to construct and then only used in error messages (that were only dprintf()ed, so never seen!) - share_mode, since we store the flags passed to ctf_link (including the share mode) in a new ctf_file_t.ctf_link_flags to help dedup get hold of it We rename others whose existing names were fairly dreadful: - done_main_member -> done_parent, using consistent terminology for .ctf as the parent of all archive members - main_input_fp -> in_fp_parent, likewise - file_name -> in_file_name, likewise We add one new member, cu_mapped. Finally, we move the various frees of things like mapping table data to the top-level ctf_link, since deduplicating links will want to do that too. include/ * ctf-api.h (ECTF_NEEDSBFD): New. (ECTF_NERR): Adjust. (ctf_link): Rename share_mode arg to flags. libctf/ * Makefile.am: Set -DNOBFD=1 in libctf-nobfd, and =0 elsewhere. * Makefile.in: Regenerated. * ctf-impl.h (ctf_link_input_name): New. (ctf_file_t) <ctf_link_flags>: New. * ctf-create.c (ctf_serialize): Adjust accordingly. * ctf-link.c: Define ctf_open as weak when PIC. (ctf_arc_close_thunk): Remove unnecessary thunk. (ctf_file_close_thunk): Likewise. (ctf_link_input_name): New. (ctf_link_input_t): New value of the ctf_file_t.ctf_link_input. (ctf_link_input_close): Adjust accordingly. (ctf_link_add_ctf_internal): New, split from... (ctf_link_add_ctf): ... here. Return error if lazy loading of CTF is not possible. Change to just call... (ctf_link_add): ... this new function. (ctf_link_add_cu_mapping): Transition to ctf_err_warn. Drop the ctf_file_close_thunk. (ctf_link_in_member_cb_arg_t) <file_name> Rename to... <in_file_name>: ... this. <arcname>: Drop. <share_mode>: Likewise (migrated to ctf_link_flags). <done_main_member>: Rename to... <done_parent>: ... this. <main_input_fp>: Rename to... <in_fp_parent>: ... this. <cu_mapped>: New. (ctf_link_one_type): Adjuwt accordingly. Transition to ctf_err_warn, removing a TODO. (ctf_link_one_variable): Note a case too common to warn about. Report in the debug stream if a cu-mapped link prevents addition of a conflicting variable. (ctf_link_one_input_archive_member): Adjust. (ctf_link_lazy_open): New, open a CTF archive for linking when needed. (ctf_link_close_one_input_archive): New, close it again. (ctf_link_one_input_archive): Adjust for lazy opening, member renames, and ctf_err_warn transition. Move the empty_link_type_mapping call to... (ctf_link): ... here. Adjut for renamings and thunk removal. Don't spuriously fail if some input contains no CTF data. (ctf_link_write): ctf_err_warn transition. * libctf.ver: Remove not-yet-stable comment.	6 years ago
Nick Alcock	8b37e7b63e	libctf, ld, binutils: add textual error/warning reporting for libctf This commit adds a long-missing piece of infrastructure to libctf: the ability to report errors and warnings using all the power of printf, rather than being restricted to one errno value. Internally, libctf calls ctf_err_warn() to add errors and warnings to a list: a new iterator ctf_errwarning_next() then consumes this list one by one and hands it to the caller, which can free it. New errors and warnings are added until the list is consumed by the caller or the ctf_file_t is closed, so you can dump them at intervals. The caller can of course choose to print only those warnings it wants. (I am not sure whether we want objdump, readelf or ld to print warnings or not: right now I'm printing them, but maybe we only want to print errors? This entirely depends on whether warnings are voluminous things describing e.g. the inability to emit single types because of name clashes or something. There are no users of this infrastructure yet, so it's hard to say.) There is no internationalization here yet, but this at least adds a place where internationalization can be added, to one of ctf_errwarning_next or ctf_err_warn. We also provide a new ctf_assert() function which uses this infrastructure to provide non-fatal assertion failures while emitting an assert-like string to the caller: to save space and avoid needlessly duplicating unchanging strings, the assertion test is inlined but the print-things-out failure case is not. All assertions in libctf will be converted to use this machinery in future commits and propagate assertion-failure errors up, so that the linker in particular cannot be killed by libctf assertion failures when it could perfectly well just print warnings and drop the CTF section. include/ * ctf-api.h (ECTF_INTERNAL): Adjust error text. (ctf_errwarning_next): New. libctf/ * ctf-impl.h (ctf_assert): New. (ctf_err_warning_t): Likewise. (ctf_file_t) <ctf_errs_warnings>: Likewise. (ctf_err_warn): New prototype. (ctf_assert_fail_internal): Likewise. * ctf-inlines.h (ctf_assert_internal): Likewise. * ctf-open.c (ctf_file_close): Free ctf_errs_warnings. * ctf-create.c (ctf_serialize): Copy it on serialization. * ctf-subr.c (ctf_err_warn): New, add an error/warning. (ctf_errwarning_next): New iterator, free and pass back errors/warnings in succession. * libctf.ver (ctf_errwarning_next): Add. ld/ * ldlang.c (lang_ctf_errs_warnings): New, print CTF errors and warnings. Assert when libctf asserts. (lang_merge_ctf): Call it. (land_write_ctf): Likewise. binutils/ * objdump.c (ctf_archive_member): Print CTF errors and warnings. * readelf.c (dump_ctf_archive_member): Likewise.	6 years ago
Nick Alcock	ec388c16cd	libctf: error out on corrupt CTF with invalid header flags If corrupt CTF with invalid header flags is passed in, return the new error ECTF_FLAGS. include/ * ctf-api.h (ECTF_FLAGS): New. (ECTF_NERR): Adjust. * ctf.h (CTF_F_MAX): New. libctf/ * ctf-open.c (ctf_bufopen_internal): Diagnose invalid flags.	6 years ago
Nick Alcock	688d28f621	libctf, next: introduce new class of easier-to-use iterators The libctf machinery currently only provides one way to iterate over its data structures: ctf__iter functions that take a callback and an arg and repeatedly call it. This works, but if you are doing a lot of iteration it is really quite inconvenient: you have to package up your local variables into structures over and over again and spawn lots of little functions even if it would be clearer in a single run of code. Look at ctf-string.c for an extreme example of how unreadable this can get, with three-line-long functions proliferating wildly. The deduplicator takes this to the Nth level. It iterates over a whole bunch of things: if we'd had to use _iter-class iterators for all of them there would be twenty additional functions in the deduplicator alone, for no other reason than that the iterator API requires it. Let's do something better. strtok_r gives us half the design: generators in a number of other languages give us the other half. The _next API allows you to iterate over CTF-like entities in a single function using a normal while loop. e.g. here we are iterating over all the types in a dict: ctf_next_t i = NULL; int hidden; ctf_id_t id; while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR) { /* do something with 'hidden' and 'id' / } if (ctf_errno (fp) != ECTF_NEXT_END) / iteration error / Here we are walking through the members of a struct with CTF ID 'struct_type': ctf_next_t i = NULL; ssize_t offset; const char name; ctf_id_t membtype; while ((offset = ctf_member_next (fp, struct_type, &i, &name, &membtype)) >= 0 { / do something with offset, name, and membtype / } if (ctf_errno (fp) != ECTF_NEXT_END) / iteration error / Like every other while loop, this means you have access to all the local variables outside the loop while inside it, with no need to tiresomely package things up in structures, move the body of the loop into a separate function, etc, as you would with an iterator taking a callback. ctf__next allocates 'i' for you on first entry (when it must be NULL), and frees and NULLs it and returns a _next-dependent flag value when the iteration is over: the fp errno is set to ECTF_NEXT_END when the iteartion ends normally. If you want to exit early, call ctf_next_destroy on the iterator. You can copy iterators using ctf_next_copy, which copies their current iteration position so you can remember loop positions and go back to them later (or ctf_next_destroy them if you don't need them after all). Each _next function returns an always-likely-to-be-useful property of the thing being iterated over, and takes pointers to parameters for the others: with very few exceptions all those parameters can be NULLs if you're not interested in them, so e.g. you can iterate over only the offsets of members of a structure this way: while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0) If you pass an iterator in use by one iteration function to another one, you get the new error ECTF_NEXT_WRONGFUN back; if you try to change ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back. Internally the ctf_next_t remembers the iteration function in use, various sizes and increments useful for almost all iterations, then uses unions to overlap the actual entities being iterated over to keep ctf_next_t size down. Iterators available in the public API so far (all tested in actual use in the deduplicator): /* Iterate over the members of a STRUCT or UNION, returning each member's offset and optionally name and member type in turn. On end-of-iteration, returns -1. / ssize_t ctf_member_next (ctf_file_t fp, ctf_id_t type, ctf_next_t it, const char name, ctf_id_t membtype); / Iterate over the members of an enum TYPE, returning each enumerand's NAME or NULL at end of iteration or error, and optionally passing back the enumerand's integer VALue. / const char ctf_enum_next (ctf_file_t fp, ctf_id_t type, ctf_next_t it, int val); /* Iterate over every type in the given CTF container (not including parents), optionally including non-user-visible types, returning each type ID and optionally the hidden flag in turn. Returns CTF_ERR on end of iteration or error. / ctf_id_t ctf_type_next (ctf_file_t fp, ctf_next_t *it, int flag, int want_hidden); /* Iterate over every variable in the given CTF container, in arbitrary order, returning the name and type of each variable in turn. The NAME argument is not optional. Returns CTF_ERR on end of iteration or error. / ctf_id_t ctf_variable_next (ctf_file_t fp, ctf_next_t it, const char name); /* Iterate over all CTF files in an archive, returning each dict in turn as a ctf_file_t, and NULL on error or end of iteration. It is the caller's responsibility to close it. Parent dicts may be skipped. Regardless of whether they are skipped or not, the caller must ctf_import the parent if need be. / ctf_file_t ctf_archive_next (const ctf_archive_t wrapper, ctf_next_t it, const char name, int skip_parent, int errp); ctf_label_next is prototyped but not implemented yet. include/ * ctf-api.h (ECTF_NEXT_END): New error. (ECTF_NEXT_WRONGFUN): Likewise. (ECTF_NEXT_WRONGFP): Likewise. (ECTF_NERR): Adjust. (ctf_next_t): New. (ctf_next_create): New prototype. (ctf_next_destroy): Likewise. (ctf_next_copy): Likewise. (ctf_member_next): Likewise. (ctf_enum_next): Likewise. (ctf_type_next): Likewise. (ctf_label_next): Likewise. (ctf_variable_next): Likewise. libctf/ * ctf-impl.h (ctf_next): New. (ctf_get_dict): New prototype. * ctf-lookup.c (ctf_get_dict): New, split out of... (ctf_lookup_by_id): ... here. * ctf-util.c (ctf_next_create): New. (ctf_next_destroy): New. (ctf_next_copy): New. * ctf-types.c (includes): Add <assert.h>. (ctf_member_next): New. (ctf_enum_next): New. (ctf_type_iter): Document the lack of iteration over parent types. (ctf_type_next): New. (ctf_variable_next): New. * ctf-archive.c (ctf_archive_next): New. * libctf.ver: Add new public functions.	6 years ago
Nick Alcock	2399827bfa	libctf: add ctf_ref This allows you to bump the refcount on a ctf_file_t, so that you can smuggle it out of iterators which open and close the ctf_file_t for you around the loop body (like ctf_archive_iter). You still can't use this to preserve a ctf_file_t for longer than the lifetime of its containing entity (e.g. ctf_archive). include/ * ctf-api.h (ctf_ref): New. libctf/ * libctf.ver (ctf_ref): New. * ctf-open.c (ctf_ref): Implement it.	6 years ago
Nick Alcock	9c23dfa5aa	libctf: add ctf_archive_count Another count that was otherwise unavailable without doing expensive operations. include/ * ctf-api.h (ctf_archive_count): New. libctf/ * ctf-archive.c (ctf_archive_count): New. * libctf.ver: New public function.	6 years ago
Nick Alcock	e0325e2ced	libctf: add ctf_member_count This returns the number of members in a struct or union, or the number of enumerations in an enum. (This was only available before now by iterating across every member, but it can be returned much faster than that.) include/ * ctf-api.h (ctf_member_count): New. libctf/ * ctf-types.c (ctf_member_count): New. * libctf.ver: New public function.	6 years ago
Nick Alcock	9b15cbb789	libctf: add ctf_type_kind_forwarded This is just like ctf_type_kind, except that forwards get the type of the thing being pointed to rather than CTF_K_FORWARD. include/ * ctf-api.h (ctf_type_kind_forwarded): New. libctf/ * ctf-types.c (ctf_type_kind_forwarded): New.	6 years ago
Nick Alcock	01d9317436	libctf: add ctf_type_name_raw We already have a function ctf_type_aname_raw, which returns the raw name of a type with no decoration for structures or arrays or anything like that: just the underlying name of whatever it is that's being ultimately pointed at. But this can be inconvenient to use, becauswe it always allocates new storage for the string and copies it in, so it can potentially fail. Add ctf_type_name_raw, which just returns the string directly out of libctf's guts: it will live until the ctf_file_t is closed (if we later gain the ability to remove types from writable dicts, it will live as long as the type lives). Reimplement ctf_type_aname_raw in terms of it. include/ * ctf-api.c (ctf_type_name_raw): New. libctf/ * ctf-types.c (ctf_type_name_raw): New. (ctf_type_aname_raw): Reimplement accordingly.	6 years ago
Nick Alcock	7eea9d3bdb	libctf: restructure error handling to reduce relocations Jose Marchesi noted that the traditional-Unix error array in ctf-error.c introduces one reloc per error to initialize the array: 58 so far. We can reduce this to zero using an array of carefully-sized individual members which is used to construct a string table, that is then referenced by the lookup functions: but doing this automatically is a pain. Bruno Haible wrote suitable code years ago: I got permission to reuse it (Bruno says "... which I hereby put in the public domain"); I modified it a tiny bit (similarly to what Ulrich Drepper did in the dsohowto text, but I redid it from scratch), commented it up a bit, and shifted the error table into that form, migrating it into the new file ctf-error.h. This has the advantage that it spotted both typos in the text of the errors in the comments in ctf-api.h and typos in the error defines in the comments in ctf-error.c, and places where the two were simply not in sync. All are now fixed. One new constant exists in ctf-api.h: CTF_NERR, since the old method of working out the number of errors in ctf-error.c was no longer usable, and it seems that the number of CTF errors is something users might reasonably want as well. It should be pretty easy to keep up to date as new errors are introduced. include/ * ctf-api.h (ECTF_): Improve comments. (ECTF_NERR): New. libctf/ ctf-error.c: Include <stddef.h>, for offsetof. (_ctf_errlist): Migrate to... (_ctf_errlist_t): ... this. (_ctf_erridx): New, indexes into _ctf_errlist_t. (_ctf_nerr): Remove. (ctf_errmsg): Adjust accordingly. * Makefile.am (BUILT_SOURCES): Note... (ctf-error.h): ... this new rule. * Makefile.in: Regenerate. * mkerrors.sed: New, process ctf-api.h to generate ctf-error.h. * .gitignore: New, ignore ctf-error.h.	6 years ago
Nick Alcock	b64751cf0b	include, libctf: typo fixes include/ * ctf-api.h: Fix typos in comments. libctf/ * ctf-impl.h: Fix typos in comments.	6 years ago
Nick Alcock	2f6ecaed66	libctf, binutils: support CTF archives like objdump objdump and readelf have one major CTF-related behavioural difference: objdump can read .ctf sections that contain CTF archives and extract and dump their members, while readelf cannot. Since the linker often emits CTF archives, this means that readelf intermittently and (from the user's perspective) randomly fails to read CTF in files that ld emits, with a confusing error message wrongly claiming that the CTF content is corrupt. This is purely because the archive-opening code in libctf was needlessly tangled up with the BFD code, so readelf couldn't use it. Here, we disentangle it, moving ctf_new_archive_internal from ctf-open-bfd.c into ctf-archive.c and merging it with the helper function in ctf-archive.c it was already using. We add a new public API function ctf_arc_bufopen, that looks very like ctf_bufopen but returns an archive given suitable section data rather than a ctf_file_t: the archive is a ctf_archive_t, so it can be called on raw CTF dictionaries (with no archive present) and will return a single-member synthetic "archive". There is a tiny lifetime tweak here: before now, the archive code could assume that the symbol section in the ctf_archive_internal wrapper structure was always owned by BFD if it was present and should always be freed: now, the caller can pass one in via ctf_arc_bufopen, wihch has the usual lifetime rules for such sections (caller frees): so we add an extra field to track whether this is an internal call from ctf-open-bfd, in which case we still free the symbol section. include/ * ctf-api.h (ctf_arc_bufopen): New. libctf/ * ctf-impl.h (ctf_new_archive_internal): Declare. (ctf_arc_bufopen): Remove. (ctf_archive_internal) <ctfi_free_symsect>: New. * ctf-archive.c (ctf_arc_close): Use it. (ctf_arc_bufopen): Fuse into... (ctf_new_archive_internal): ... this, moved across from... * ctf-open-bfd.c: ... here. (ctf_bfdopen_ctfsect): Use ctf_arc_bufopen. * libctf.ver: Add it. binutils/ * readelf.c (dump_section_as_ctf): Support .ctf archives using ctf_arc_bufopen. Automatically load the .ctf member of such archives as the parent of all other members, unless specifically overridden via --ctf-parent. Split out dumping code into... (dump_ctf_archive_member): ... here, as in objdump, and call it once per archive member. (dump_ctf_indent_lines): Code style fix.	6 years ago
Alan Modra	b3adc24a07	Update year range in copyright notice of binutils files	6 years ago
Nick Alcock	de07e349be	libctf: remove ctf_malloc, ctf_free and ctf_strdup These just get in the way of auditing for erroneous usage of strdup and add a huge irregular surface of "ctf_malloc or malloc? ctf_free or free? ctf_strdup or strdup?" ctf_malloc and ctf_free usage has not reliably matched up for many years, if ever, making the whole game pointless. Go back to malloc, free, and strdup like everyone else: while we're at it, fix a bunch of places where we weren't properly checking for OOM. This changes the interface of ctf_cuname_set and ctf_parent_name_set, which could strdup but could not return errors (like ENOMEM). New in v4. include/ * ctf-api.h (ctf_cuname_set): Can now fail, returning int. (ctf_parent_name_set): Likewise. libctf/ * ctf-impl.h (ctf_alloc): Remove. (ctf_free): Likewise. (ctf_strdup): Likewise. * ctf-subr.c (ctf_alloc): Remove. (ctf_free): Likewise. * ctf-util.c (ctf_strdup): Remove. * ctf-create.c (ctf_serialize): Use malloc, not ctf_alloc; free, not ctf_free; strdup, not ctf_strdup. (ctf_dtd_delete): Likewise. (ctf_dvd_delete): Likewise. (ctf_add_generic): Likewise. (ctf_add_function): Likewise. (ctf_add_enumerator): Likewise. (ctf_add_member_offset): Likewise. (ctf_add_variable): Likewise. (membadd): Likewise. (ctf_compress_write): Likewise. (ctf_write_mem): Likewise. * ctf-decl.c (ctf_decl_push): Likewise. (ctf_decl_fini): Likewise. (ctf_decl_sprintf): Likewise. Check for OOM. * ctf-dump.c (ctf_dump_append): Use malloc, not ctf_alloc; free, not ctf_free; strdup, not ctf_strdup. (ctf_dump_free): Likewise. (ctf_dump): Likewise. * ctf-open.c (upgrade_types_v1): Likewise. (init_types): Likewise. (ctf_file_close): Likewise. (ctf_bufopen_internal): Likewise. Check for OOM. (ctf_parent_name_set): Likewise: report the OOM to the caller. (ctf_cuname_set): Likewise. (ctf_import): Likewise. * ctf-string.c (ctf_str_purge_atom_refs): Use malloc, not ctf_alloc; free, not ctf_free; strdup, not ctf_strdup. (ctf_str_free_atom): Likewise. (ctf_str_create_atoms): Likewise. (ctf_str_add_ref_internal): Likewise. (ctf_str_remove_ref): Likewise. (ctf_str_write_strtab): Likewise.	7 years ago
Nick Alcock	791915db42	libctf: handle nonrepresentable types at link time GCC can emit references to type 0 to indicate that this type is one that is not representable in the version of CTF it emits (for instance, version 3 cannot encode vector types). Type 0 is already used in the function section to indicate padding inserted to skip functions we do not want to encode the type of, so using zero in this way is a good extension of the format: but libctf reports such types as ECTF_BADID, which is indistinguishable from file corruption via links to truly nonexistent types with IDs like 0xDEADBEEF etc, which we really do want to stop for. In particular, this stops all traversals of types dead at this point, preventing us from even dumping CTF files containing unrepresentable types to see what's going on! So add a new error, ECTF_NONREPRESENTABLE, which is returned by recursive type resolution when a reference to a zero type is found. (No zero type is ever emitted into the CTF file by GCC, only references to one). We can't do much with types that are ultimately nonrepresentable, but we can do enough to keep functioning. Adjust ctf_add_type to ensure that top-level types of type zero and structure and union members of ultimate type zero are simply skipped without reporting an error, so we can copy structures and unions that contain nonrepresentable members (skipping them and leaving a hole where they would be, so no consumers downstream of the linker need to worry about this): adjust the dumper so that we dump members of nonrepresentable types in a simple form that indicates nonrepresentability rather than terminating the dump, and do not falsely assume all errors to be -ENOMEM: adjust the linker so that types that fail to get added are simply skipped, so that both nonrepresentable types and outright errors do not terminate the type addition, which could skip many valid types and cause further errors when variables of those types are added. In future, when we gain the ability to call back to the linker to report link-time type resolution errors, we should report failures to add all but nonrepresentable types. But we can't do that yet. v5: Fix tabdamage. include/ * ctf-api.h (ECTF_NONREPRESENTABLE): New. libctf/ * ctf-types.c (ctf_type_resolve): Return ECTF_NONREPRESENTABLE on type zero. * ctf-create.c (ctf_add_type): Detect and skip nonrepresentable members and types. (ctf_add_variable): Likewise for variables pointing to them. * ctf-link.c (ctf_link_one_type): Do not warn for nonrepresentable type link failure, but do warn for others. * ctf-dump.c (ctf_dump_format_type): Likewise. Do not assume all errors to be ENOMEM. (ctf_dump_member): Likewise. (ctf_dump_type): Likewise. (ctf_dump_header_strfield): Do not assume all errors to be ENOMEM. (ctf_dump_header_sectfield): Do not assume all errors to be ENOMEM. (ctf_dump_header): Likewise. (ctf_dump_label): likewise. (ctf_dump_objts): likewise. (ctf_dump_funcs): likewise. (ctf_dump_var): likewise. (ctf_dump_str): Likewise.	7 years ago
Nick Alcock	87279e3cef	libctf: installable libctf as a shared library This lets other programs read and write CTF-format data. Two versioned shared libraries are created: libctf.so and libctf-nobfd.so. They contain identical content except that libctf-nobfd.so contains no references to libbfd and does not implement ctf_open, ctf_fdopen, ctf_bfdopen or ctf_bfdopen_ctfsect, so it can be used by programs that cannot use BFD, like readelf. The soname major version is presently .0 until the linker API stabilizes, when it will flip to .1 and hopefully never change again. New in v3. v4: libtoolize and turn into a pair of shared libraries. Drop --enable-install-ctf: now controlled by --enable-shared and --enable-install-libbfd, like everything else. v5: Add ../bfd to ACLOCAL_AMFLAGS and AC_CONFIG_MACRO_DIR. Fix tabdamage. * Makefile.def (host_modules): libctf is no longer no_install. * Makefile.in: Regenerated. libctf/ * configure.ac (AC_DISABLE_SHARED): New, like opcodes/. (LT_INIT): Likewise. (AM_INSTALL_LIBBFD): Likewise. (dlopen): Note why this is necessary in a comment. (SHARED_LIBADD): Initialize for possibly-PIC libiberty: derived from opcodes/. (SHARED_LDFLAGS): Likewise. (BFD_LIBADD): Likewise, for libbfd. (BFD_DEPENDENCIES): Likewise. (VERSION_FLAGS): Initialize, using a version script if ld supports one, or libtool -export-symbols-regex otherwise. (AC_CONFIG_MACRO_DIR): Add ../BFD. * Makefile.am (ACLOCAL_AMFLAGS): Likewise. (INCDIR): New. (AM_CPPFLAGS): Use $(srcdir), not $(top_srcdir). (noinst_LIBRARIES): Replace with... [INSTALL_LIBBFD] (lib_LTLIBRARIES): This, or... [!INSTALL_LIBBFD] (noinst_LTLIBRARIES): ... this, mentioning new libctf-nobfd.la as well. [INSTALL_LIBCTF] (include_HEADERS): Add the CTF headers. [!INSTALL_LIBCTF] (include_HEADERS): New, empty. (libctf_a_SOURCES): Rename to... (libctf_nobfd_la_SOURCES): ... this, all of libctf other than ctf-open-bfd.c. (libctf_la_SOURCES): Now derived from libctf_nobfd_la_SOURCES, with ctf-open-bfd.c added. (libctf_nobfd_la_LIBADD): New, using @SHARED_LIBADD@. (libctf_la_LIBADD): New, using @BFD_LIBADD@ as well. (libctf_la_DEPENDENCIES): New, using @BFD_DEPENDENCIES@. * Makefile.am [INSTALL_LIBCTF]: Use it. * aclocal.m4: Add ../bfd/acinclude.m4, ../config/acx.m4, and the libtool macros. * libctf.ver: New, everything is version LIBCTF_1.0 currently (even the unstable components). * Makefile.in: Regenerated. * config.h.in: Likewise. * configure: Likewise. binutils/ * Makefile.am (LIBCTF): Mention the .la file. (LIBCTF_NOBFD): New. (readelf_DEPENDENCIES): Use it. (readelf_LDADD): Likewise. * Makefile.in: Regenerated. ld/ * configure.ac (TESTCTFLIB): Set to the .so or .a, like TESTBFDLIB. * Makefile.am (TESTCTFLIB): Use it. (LIBCTF): Use the .la file. (check-DEJAGNU): Use it. * Makefile.in: Regenerated. * configure: Likewise. include/ * ctf-api.h: Note the instability of the ctf_link interfaces.	7 years ago
Nick Alcock	7e97445a5a	libctf: get rid of a disruptive public include of <sys/param.h> This hoary old header defines things like MAX that users of libctf might perfectly reasonably define themselves. The CTF headers do not need it: move it into libctf/ctf-impl.h instead. include/ * ctf-api.h (includes): No longer include <sys/param.h>. libctf/ * ctf-impl.h (includes): Include <sys/param.h> here.	7 years ago
Nick Alcock	49ea9b450b	libctf: add CU-mapping machinery Once the deduplicator is capable of actually detecting conflicting types with the same name (i.e., not yet) we will place such conflicting types, and types that depend on them, into CTF dictionaries that are the child of the main dictionary we usually emit: currently, this will lead to the .ctf section becoming a CTF archive rather than a single dictionary, with the default-named archive member (_CTF_SECTION, or NULL) being the main shared dictionary with most of the types in it. By default, the sections are named after the compilation unit they come from (complete path and all), with the cuname field in the CTF header providing further evidence of the name without requiring the caller to engage in tiresome parsing. But some callers may not wish the mapping from input CU to output sub-dictionary to be purely CU-based. The machinery here allows this to be freely changed, in two ways: - callers can call ctf_link_add_cu_mapping to specify that a single input compilation unit should have its types placed in some other CU if they conflict: the CU will always be created, even if empty, so the consuming program can depend on its existence. You can map multiple input CUs to one output CU to force all their types to be merged together: if some of those types conflict, the behaviour is currently unspecified (the new deduplicator will specify it). - callers can call ctf_link_set_memb_name_changer to provide a function which is passed every CTF sub-dictionary name in turn (including _CTF_SECTION) and can return a new name, or NULL if no change is desired. The mapping from input to output names should not map two input names to the same output name: if this happens, the two are not merged but will result in an archive with two members with the same name (technically valid, but it's hard to access the second same-named member: you have to do an iteration over archive members). This is used by the kernel's ctfarchive machinery (not yet upstream) to encode CTF under member names like {module name}.ctf rather than .ctf.CU, but it is anticipated that other large projects may wish to have their own storage for CTF outside of .ctf sections and may wish to have new naming schemes that suit their special-purpose consumers. New in v3. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (ctf_link_add_cu_mapping): New. (ctf_link_memb_name_changer_f): New. (ctf_link_set_memb_name_changer): New. libctf/ * ctf-impl.h (ctf_file_t) <ctf_link_cu_mappping>: New. <ctf_link_memb_name_changer>: Likewise. <ctf_link_memb_name_changer_arg>: Likewise. * ctf-create.c (ctf_update): Update accordingly. * ctf-open.c (ctf_file_close): Likewise. * ctf-link.c (ctf_create_per_cu): Apply the cu mapping. (ctf_link_add_cu_mapping): New. (ctf_link_set_memb_name_changer): Likewise. (ctf_change_parent_name): New. (ctf_name_list_accum_cb_arg_t) <dynames>: New, storage for names allocated by the caller's ctf_link_memb_name_changer. <ndynames>: Likewise. (ctf_accumulate_archive_names): Call the ctf_link_memb_name_changer. (ctf_link_write): Likewise (for _CTF_SECTION only): also call ctf_change_parent_name. Free any resulting names.	7 years ago
Nick Alcock	eabb7154df	libctf: add linking of the variable section The compiler describes the name and type of all file-scope variables in this section. Merging it at link time requires using the type mapping added in the previous commit to determine the appropriate type for the variable in the output, given its type in the input: we check the shared container first, and if the type doesn't exist there, it must be a conflicted type in the per-CU child, and the variable should go there too. We also put the variable in the per-CU child if a variable with the same name but a different type already exists in the parent: we ignore any such conflict in the child because CTF cannot represent such things, nor can they happen unless a third-party linking program has overridden the mapping of CU to CTF archive member name (using machinery added in a later commit). v3: rewritten using an algorithm that actually works in the case of conflicting names. Some code motion from the next commit. Set the per-CU parent name. v4: check for strdup failure. v5: fix tabdamage. include/ * ctf-api.h (ECTF_INTERNAL): New. libctf/ * ctf-link.c (ctf_create_per_cu): New, refactored out of... (ctf_link_one_type): ... here, with parent-name setting added. (check_variable): New. (ctf_link_one_variable): Likewise. (ctf_link_one_input_archive_member): Call it. * ctf-error.c (_ctf_errlist): Updated with new errors.	7 years ago
Nick Alcock	72c83edd92	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.	7 years ago
Nick Alcock	5537f9b9a3	libctf: write CTF files to memory, and CTF archives to fds Before now, we've been able to write CTF files to gzFile descriptors or fds, and CTF archives to named files only. Make this a bit less irregular by allowing CTF archives to be written to fds with the new function ctf_arc_write_fd: also allow CTF files to be written to a new memory buffer via ctf_write_mem. (It would be nice to complete things by adding a new function to write CTF archives to memory, but this is too difficult to do given the short time the linker is expected to be writing them out: we will transition to a better format in format v4, though we will always support reading CTF archives that are stored in .ctf sections.) include/ * ctf-api.h (ctf_arc_write_fd): New. (ctf_write_mem): Likewise. (ctf_gzwrite): Spacing fix. libctf/ * ctf-archive.c (ctf_arc_write): Split off, and reimplement in terms of... (ctf_arc_write_fd): ... this new function. * ctf-create.c (ctf_write_mem): New.	7 years ago
Nick Alcock	0ac6231298	libctf: Add iteration over non-root types The existing function ctf_type_iter lets you iterate over root-visible types (types you can look up by name). There is no way to iterate over non-root-visible types, which is troublesome because both the linker and dumper want to do that. So add a new function that can do it: the callback it takes accepts an extra parameter which indicates whether the type is root-visible or not. include/ * ctf-api.h (ctf_type_all_f): New. (ctf_type_iter_all): New. libctf/ * ctf_types.c (ctf_type_iter_all): New.	7 years ago
Nick Alcock	fd55eae84d	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.	7 years ago
Nick Alcock	12a0b67d28	libctf: introduce ctf_func_type_{info,args}, ctf_type_aname_raw 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.	7 years ago
Jose E. Marchesi	a0486bac41	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.	7 years ago
Nick Alcock	a30b3e182a	libctf: debug dumping This introduces ctf_dump(), an iterator which returns a series of strings, each representing a debugging dump of one item from a given section in the CTF file. The items may be multiline: a callback is provided to allow the caller to decorate each line as they desire before the line is returned. libctf/ * ctf-dump.c: New. include/ * ctf-api.h (ctf_dump_decorate_f): New. (ctf_dump_state_t): new. (ctf_dump): New.	7 years ago

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