This commit fixes a compilation failure in a couple of libctf files
due to the use of EOVERFLOW and ENOTSUP, which are not defined
when compiling on MinGW.
libctf/ChangeLog:
PR binutils/25155:
* ctf-create.c (EOVERFLOW): If not defined by system header,
redirect to ERANGE as a poor man's substitute.
* ctf-subr.c (ENOTSUP): If not defined, use ENOSYS instead.
(cherry picked from commit 50500ecfefd6acc4c7f6c2a95bc0ae1945103220)
This utility function is almost useless (all it does is casts the result
of a strerror) but has a seriously confusing name. Over and over again
I have accidentally called it instead of ctf_errmsg, and hidden a
time-bomb for myself in a hard-to-test error-handling path: since
ctf_strerror is just a strerror wrapper, it cannot handle CTF errnos,
unlike ctf_errmsg. It's astonishingly lucky that none of these errors
have crept into any commits to date.
Fuse it into ctf_errmsg and drop it.
libctf/
* ctf-impl.h (ctf_strerror): Delete.
* ctf-subr.c (ctf_strerror): Likewise.
* ctf-error.c (ctf_errmsg): Stop using ctf_strerror: just use
strerror directly.
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.
The deduplicator can emit enormous amounts of debugging output,
so much so that a later commit will introduce a new configure flag
that configures most of it out (and configures it out by default).
It became clear that when this configure flag is on, but debugging is
not enabled via the LIBCTF_DEBUG environment variable, up to 10% of
runtime can be spent on branch mispredictions checking the _libctf_debug
variable. Mark it unlikely to be set (when it is set, performance is
likely to be the least of your concerns).
libctf/
* ctf-subr.c (ctf_dprintf): _libctf_debug is unlikely to be set.
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.
This allocator has the ostensible benefit that it lets us mprotect() the
memory used for CTF storage: but in exchange for this it adds
considerable complexity, since we have to track allocation sizes
ourselves for use at freeing time, note whether the data we are storing
was ctf_data_alloc()ed or not so we know if we can safely mprotect()
it... and while the mprotect()ing has found few bugs, it *has* been the
cause of more than one due to errors in all this tracking leading to us
mprotect()ing bits of the heap and stuff like that.
We are about to start composing CTF buffers from pieces so that we can
do usage-based optimizations on the strtab. This means we need
realloc(), which needs nonportable mremap() and *more* tracking of the
*original* allocation size, and the complexity and bureaucracy of all of
this is just too high for its negligible benefits.
Drop the whole thing and just use malloc() like everyone else. It knows
better than we do when it is safe to use mmap() under the covers,
anyway.
While we're at it, don't leak the entire buffer if ctf_compress_write()
fails to compress it.
libctf/
* ctf-subr.c (_PAGESIZE): Remove.
(ctf_data_alloc): Likewise.
(ctf_data_free): Likewise.
(ctf_data_protect): Likewise.
* ctf-impl.h: Remove declarations.
* ctf-create.c (ctf_update): No longer call ctf_data_protect: use
ctf_free, not ctf_data_free.
(ctf_compress_write): Use ctf_data_alloc, not ctf_alloc. Free
the buffer again on compression error.
* ctf-open.c (ctf_set_base): No longer track the size: call
ctf_free, not ctf_data_free.
(upgrade_types): Likewise. Call ctf_alloc, not ctf_data_alloc.
(ctf_bufopen): Likewise. No longer call ctf_data_protect.
Tested on x86_64-pc-linux-gnu, x86_64-unknown-freebsd12.0,
sparc-sun-solaris2.11, i686-pc-cygwin, i686-w64-mingw32.
libctf/
* ctf-archive.c (arc_mmap_header): Mark fd as potentially unused.
* ctf-subr.c (ctf_data_protect): Mark both args as potentially unused.
This old Solaris standard allows callers to specify that they are
expecting one particular API and/or CTF file format from the library.
libctf/
* ctf-impl.h (_libctf_version): New declaration.
* ctf-subr.c (_libctf_version): Define it.
(ctf_version): New.
include/
* ctf-api.h (ctf_version): New.
The memory-allocation wrappers are simple things to allow malloc
interposition: they are only used inconsistently at present, usually
where malloc debugging was required in the past.
These provide a default implementation that is environment-variable
triggered (initialized on the first call to the libctf creation and
file-opening functions, the first functions people will use), and
a ctf_setdebug()/ctf_getdebug() pair that allows the caller to
explicitly turn debugging off and on. If ctf_setdebug() is called,
the automatic setting from an environment variable is skipped.
libctf/
* ctf-impl.h: New file.
* ctf-subr.c: New file.
include/
* ctf-api.h (ctf_setdebug): New.
(ctf_getdebug): Likewise.
