binutils: CTF support for objdump and readelf
This introduces CTF support for objdump and readelf. objdump has the
following new arguments:
--ctf=SECTION: display CTF in the given SECTION
--ctf-parent=SECTION: name of CTF section that is the parent of this section
readelf has the above, and these two as well:
--ctf-symbols=SECTION: name of symbol table section (optional)
--ctf-strings=SECTION: name of string table section (optional)
(objdump can always use BFD machinery to determine the applicable string
and symbol tables automatically, so these arguments are unnecessary.)
Nearly all the work is done by the ctf_dump machinery in libctf: most of
the remaining work is option-processing and section-reading, and thus is
different for objdump and readelf: the minimal amount of similar code
remaining is, in my view, too small to share, particularly given that
objdump uses ctf_bfdopen() and readelf uses ctf_simple_open() since it
doesn't have a bfd.
I am not particularly satisfied with the way resources are freed in
either of these (I was forced to do it at the top level, for lack of
anywhere else to free resources allocated during option processing), but
I can't see any better way to do it without introducing new
infrastructure for no other purpose.
There are essentially arbitrary ordering changes to the Makefile.in's
order of libtool-related stuff that I can't get rid of, but they have no
semantic effect. (It is possible that some hunks of these changes could
be dropped, but that seems a bit risky to me.)
binutils/
* objdump.c (ctf-api.h): New include.
(dump_ctf_section_info): New variable.
(dump_ctf_section_name): Likewise.
(usage): Describe new options.
(enum option_values): Add OPTION_CTF and OPTION_CTF_PARENT.
(main): Use them to add --ctf and --ctf-parent.
(read_section_stabs): Add new parameter, entsize_ptr.
(find_stabs_section): Adjust accordingly.
(make_ctfsect): New.
(dump_ctf_indent_lines): New.
(dump_ctf_archive_member): New.
(dump_ctf): New.
(dump_bfd): Call it. Free resources afterwards.
* readelf.c (ctf-api.h): New include.
(CTF_DUMP): New.
(static bfd_boolean do_ctf): Likewise.
(dump_ctf_parent_name): Likewise.
(dump_ctf_symtab_name): Likewise.
(dump_ctf_strtab_name): Likewise.
(OPTION_CTF_DUMP): Likewise.
(OPTION_CTF_PARENT): Likewise.
(OPTION_CTF_SYMBOLS): Likewise.
(OPTION_CTF_STRINGS): Likewise.
(options): Add them.
(usage): Likewise.
(parse_args): Handle the new options, requesting CTF_DUMP.
(process_section_contents): Handle CTF_DUMP.
(shdr_to_ctf_sect): New.
(dump_ctf_indent_lines): New.
(dump_section_as_ctf): New.
(main): Free resources.
* Makefile.am (LIBCTF): New variable.
(objdump_DEPENDENCIES): Use it.
(readelf_DEPENDENCIES): Likewise.
(objdump_LDADD): Likewise.
(readelf_LDADD): Likewise.
* aclocal.m4: Regenerated.
* Makefile.in: Likewise.
* doc/binutils.texi (objdump): Document the new options.
(readelf): Likewise.
* doc/ctf.options.texi: New.
* doc/Makefile.in: Regenerated.
* NEWS: Mention the new feature.
2019-04-24 19:04:33 +08:00
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@c This file contains the entry for the --ctf, --ctf-parent, --ctf-symbols, -and
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@c --ctf-strings options that are common to both readelf and objdump.
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2021-10-25 18:17:02 +08:00
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@item --ctf[=@var{section}]
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binutils: CTF support for objdump and readelf
This introduces CTF support for objdump and readelf. objdump has the
following new arguments:
--ctf=SECTION: display CTF in the given SECTION
--ctf-parent=SECTION: name of CTF section that is the parent of this section
readelf has the above, and these two as well:
--ctf-symbols=SECTION: name of symbol table section (optional)
--ctf-strings=SECTION: name of string table section (optional)
(objdump can always use BFD machinery to determine the applicable string
and symbol tables automatically, so these arguments are unnecessary.)
Nearly all the work is done by the ctf_dump machinery in libctf: most of
the remaining work is option-processing and section-reading, and thus is
different for objdump and readelf: the minimal amount of similar code
remaining is, in my view, too small to share, particularly given that
objdump uses ctf_bfdopen() and readelf uses ctf_simple_open() since it
doesn't have a bfd.
I am not particularly satisfied with the way resources are freed in
either of these (I was forced to do it at the top level, for lack of
anywhere else to free resources allocated during option processing), but
I can't see any better way to do it without introducing new
infrastructure for no other purpose.
There are essentially arbitrary ordering changes to the Makefile.in's
order of libtool-related stuff that I can't get rid of, but they have no
semantic effect. (It is possible that some hunks of these changes could
be dropped, but that seems a bit risky to me.)
binutils/
* objdump.c (ctf-api.h): New include.
(dump_ctf_section_info): New variable.
(dump_ctf_section_name): Likewise.
(usage): Describe new options.
(enum option_values): Add OPTION_CTF and OPTION_CTF_PARENT.
(main): Use them to add --ctf and --ctf-parent.
(read_section_stabs): Add new parameter, entsize_ptr.
(find_stabs_section): Adjust accordingly.
(make_ctfsect): New.
(dump_ctf_indent_lines): New.
(dump_ctf_archive_member): New.
(dump_ctf): New.
(dump_bfd): Call it. Free resources afterwards.
* readelf.c (ctf-api.h): New include.
(CTF_DUMP): New.
(static bfd_boolean do_ctf): Likewise.
(dump_ctf_parent_name): Likewise.
(dump_ctf_symtab_name): Likewise.
(dump_ctf_strtab_name): Likewise.
(OPTION_CTF_DUMP): Likewise.
(OPTION_CTF_PARENT): Likewise.
(OPTION_CTF_SYMBOLS): Likewise.
(OPTION_CTF_STRINGS): Likewise.
(options): Add them.
(usage): Likewise.
(parse_args): Handle the new options, requesting CTF_DUMP.
(process_section_contents): Handle CTF_DUMP.
(shdr_to_ctf_sect): New.
(dump_ctf_indent_lines): New.
(dump_section_as_ctf): New.
(main): Free resources.
* Makefile.am (LIBCTF): New variable.
(objdump_DEPENDENCIES): Use it.
(readelf_DEPENDENCIES): Likewise.
(objdump_LDADD): Likewise.
(readelf_LDADD): Likewise.
* aclocal.m4: Regenerated.
* Makefile.in: Likewise.
* doc/binutils.texi (objdump): Document the new options.
(readelf): Likewise.
* doc/ctf.options.texi: New.
* doc/Makefile.in: Regenerated.
* NEWS: Mention the new feature.
2019-04-24 19:04:33 +08:00
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@cindex CTF
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@cindex Compact Type Format
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Display the contents of the specified CTF section. CTF sections themselves
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contain many subsections, all of which are displayed in order.
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2021-10-25 18:17:02 +08:00
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By default, display the name of the section named @var{.ctf}, which is the
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name emitted by @command{ld}.
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binutils: CTF support for objdump and readelf
This introduces CTF support for objdump and readelf. objdump has the
following new arguments:
--ctf=SECTION: display CTF in the given SECTION
--ctf-parent=SECTION: name of CTF section that is the parent of this section
readelf has the above, and these two as well:
--ctf-symbols=SECTION: name of symbol table section (optional)
--ctf-strings=SECTION: name of string table section (optional)
(objdump can always use BFD machinery to determine the applicable string
and symbol tables automatically, so these arguments are unnecessary.)
Nearly all the work is done by the ctf_dump machinery in libctf: most of
the remaining work is option-processing and section-reading, and thus is
different for objdump and readelf: the minimal amount of similar code
remaining is, in my view, too small to share, particularly given that
objdump uses ctf_bfdopen() and readelf uses ctf_simple_open() since it
doesn't have a bfd.
I am not particularly satisfied with the way resources are freed in
either of these (I was forced to do it at the top level, for lack of
anywhere else to free resources allocated during option processing), but
I can't see any better way to do it without introducing new
infrastructure for no other purpose.
There are essentially arbitrary ordering changes to the Makefile.in's
order of libtool-related stuff that I can't get rid of, but they have no
semantic effect. (It is possible that some hunks of these changes could
be dropped, but that seems a bit risky to me.)
binutils/
* objdump.c (ctf-api.h): New include.
(dump_ctf_section_info): New variable.
(dump_ctf_section_name): Likewise.
(usage): Describe new options.
(enum option_values): Add OPTION_CTF and OPTION_CTF_PARENT.
(main): Use them to add --ctf and --ctf-parent.
(read_section_stabs): Add new parameter, entsize_ptr.
(find_stabs_section): Adjust accordingly.
(make_ctfsect): New.
(dump_ctf_indent_lines): New.
(dump_ctf_archive_member): New.
(dump_ctf): New.
(dump_bfd): Call it. Free resources afterwards.
* readelf.c (ctf-api.h): New include.
(CTF_DUMP): New.
(static bfd_boolean do_ctf): Likewise.
(dump_ctf_parent_name): Likewise.
(dump_ctf_symtab_name): Likewise.
(dump_ctf_strtab_name): Likewise.
(OPTION_CTF_DUMP): Likewise.
(OPTION_CTF_PARENT): Likewise.
(OPTION_CTF_SYMBOLS): Likewise.
(OPTION_CTF_STRINGS): Likewise.
(options): Add them.
(usage): Likewise.
(parse_args): Handle the new options, requesting CTF_DUMP.
(process_section_contents): Handle CTF_DUMP.
(shdr_to_ctf_sect): New.
(dump_ctf_indent_lines): New.
(dump_section_as_ctf): New.
(main): Free resources.
* Makefile.am (LIBCTF): New variable.
(objdump_DEPENDENCIES): Use it.
(readelf_DEPENDENCIES): Likewise.
(objdump_LDADD): Likewise.
(readelf_LDADD): Likewise.
* aclocal.m4: Regenerated.
* Makefile.in: Likewise.
* doc/binutils.texi (objdump): Document the new options.
(readelf): Likewise.
* doc/ctf.options.texi: New.
* doc/Makefile.in: Regenerated.
* NEWS: Mention the new feature.
2019-04-24 19:04:33 +08:00
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binutils: make objdump/readelf --ctf-parent actually useful
This option has been present since the very early days of the
development of libctf as part of binutils, and it shows. Back in the
earliest days, I thought we might handle ambiguous types by introducing
new ELF sections on the fly named things like .ctf.foo.c for ambiguous
types found only in foo.c, etc. This turned out to be a terrible idea,
so we moved to using a CTF archive in the .ctf section which contained
all the CTF dictionaries -- but the --ctf-parent option in objdump and
readelf was never adjusted, and lingered as a mechanism to specify CTF
parent dictionaries in sections other than .ctf, even though the linker
has no way to produce parent dictionaries in different sections from
their children, libctf's ctf_open can't handle such split-up
parent/child dicts, and they are never found in the wild, emitted by GNU
ld or by any known third-party linking tool.
Meanwhile, the actually-useful ctf_link feature (albeit not used by ld)
which lets you remap the names of CTF archive members (so you can end up
with a parent archive member named something other than ".ctf", still
contained with all its children in a single .ctf section) had no support
in objdump or readelf: there was no way to tell them that these members
were parents, so all the types in the associated child dicts always
appeared corrupted, referencing nonexistent types from a parent objdump
couldn't find.
So adjust --ctf-parent so that rather than taking a section name it
takes a member name instead (if not specified, the name is ".ctf", which
is what GNU ld emits). Because the option was always useless before
now, this is expected to have no backward-compatibility implications.
As part of this, we have to slightly adjust the code which skips the
archive member name if redundant: right now it skips it if it's ".ctf",
on the assumption that this name will almost always be at the start
of the objdump output and thus we'll end up with a shared dump
and then smaller, headed dumps for the per-TU child dicts; but if
the parent name has been changed, that won't be true any more.
So change the rules to "members named .ctf which appear first in the
first have their member name skipped". Since we now need to count
members, move from ctf_archive_iter (for which passing in extra
parameters requires defining a new struct and is clumsy) to
ctf_archive_next, allowing us to just *call* dump_ctf_archive_member and
maintain a member count in the obvious way. In the process we fix a
tiny difference between readelf and objdump: if a ctf_dump ever failed,
readelf skipped every later member, while objdump tried to keep going as
much as it could. For a dumping tool the former is clearly preferable.
binutils/ChangeLog
2021-10-25 Nick Alcock <nick.alcock@oracle.com>
* objdump.c (usage): --ctf-parent now takes a name, not a section.
(dump_ctf): Don't open a separate section; use the parent_name in
ctf_dict_open instead. Use ctf_archive_next, not ctf_archive_iter,
so we can pass down a member count.
(dump_ctf_archive_member): Add the member count; don't return
anything. Import parents into children no matter what the
parent's name, while still avoiding displaying the header for the
common parent name of ".ctf".
* readelf.c (usage): Adjust similarly.
(dump_section_as_ctf): Likewise.
(dump_ctf_archive_member): Likewise. Never stop iterating over
archive members, even if ctf_dump of one member fails.
* doc/ctf.options.texi: Adjust.
2021-10-25 18:17:02 +08:00
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@item --ctf-parent=@var{member}
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If the CTF section contains ambiguously-defined types, it will consist
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of an archive of many CTF dictionaries, all inheriting from one
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dictionary containing unambiguous types. This member is by default
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named @var{.ctf}, like the section containing it, but it is possible to
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change this name using the @code{ctf_link_set_memb_name_changer}
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function at link time. When looking at CTF archives that have been
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created by a linker that uses the name changer to rename the parent
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archive member, @option{--ctf-parent} can be used to specify the name
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used for the parent.
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