This diff adds support for SHT_GROUP sections to llvm-objcopy.
Some sections are interrelated and comprise a group.
For example, a definition of an inline function might require,
in addition to the section containing its instructions,
a read-only data section containing literals referenced inside the function.
A section of the type SHT_GROUP contains the indices of the group members,
therefore, it needs to be updated whenever the indices change.
Similarly, the fields sh_link, sh_info should be recalculated as well.
[Resubmit r328012 with the proper handling of endianness]
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D43996
llvm-svn: 328143
This diff adds support for SHT_GROUP sections to llvm-objcopy.
Some sections are interrelated and comprise a group.
For example, a definition of an inline function might require,
in addition to the section containing its instructions,
a read-only data section containing literals referenced inside the function.
A section of the type SHT_GROUP contains the indices of the group members,
therefore, it needs to be updated whenever the indices change.
Similarly, the fields sh_link, sh_info should be recalculated as well.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D43996
llvm-svn: 328012
Because of -ffunction-sections (and maybe other use cases I'm not aware of?) it
can occur that we need more than 0xfeff sections but ELF dosn't support that
many sections. To solve this problem SHN_XINDEX exists and with it come a whole
host of changes for section indexes everywhere. This change adds support for
those cases which should allow llvm-objcopy to copy binaries that have an
arbitrary number of sections.
Differential Revision: https://reviews.llvm.org/D42516
llvm-svn: 326940
This diff fixes the name of the argument of
setSymTab and makes setSymTab/setStrTab private
(to make the public interface a bit cleaner).
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D43661
llvm-svn: 326005
Summary:
The current implementation was writing the file name without the extension
whereas GNU objcopy writes the full filename. With this change GDB will now
load the .debug file instead of silently ignoring it.
Reviewers: jakehehrlich, jhenderson
Reviewed By: jakehehrlich
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43474
llvm-svn: 325528
Some ELF files produced by lld may have zero-size segment placeholders as shown
below. Since GNU_STACK Offset is 0, the current code makes it the lowest used
offset, and relocates all the segments over the ELF header. The resulting
binary is total garbage.
This change fixes how llvm-objcopy handles PT_PHDR properlly by treating ELF
headers and the program header table as segments to allow the layout algorithm
decide where those should go.
Author: vit9696
Differential Revision: https://reviews.llvm.org/D42872
llvm-svn: 325189
If the output file is not specified make the modifications in-place
(like binutils objcopy does). In particular, this fixes
the behavior of Clang -gsplit-dwarf (if Clang is configured to use llvm-objcopy),
previously it was creating .dwo files, but still leaving *dwo* sections in
the original binary.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D42873
llvm-svn: 324783
Tests were working on my system because the old correct files were left over
and the new bug was that the output files were not being output at all.
Consequently the test work on my system but fail on any other system.
This reverts commit r323484.
llvm-svn: 323486
While writing code for input and output formats in llvm-objcopy it became
apparent that there was a code health problem. This change attempts to solve
that problem by refactoring the code to use Reader and Writer objects that can
read in different objects in different formats, convert them to a single shared
internal representation, and then write them to any other representation.
New classes:
Reader: the base class used to construct instances of the internal
representation
Writer: the base class used to write out instances of the internal
representation
ELFBuilder: a helper class for ELFWriter that takes an ELFFile and converts it
to a Object
SectionVisitor: it became necessary to remove writeSection from SectionBase
because, under the new Reader/Writer scheme, it's possible to convert between
ELF Types such as ELF32LE and ELF32BE. This isn't possible with writeSection
because it (dynamically) depends on the underlying section type *and*
(statically) depends on the ELF type. Bad things would happen if the underlying
sections for ELF32LE were used for writing to ELF64BE. To avoid this code smell
(which would have compiled, run, and output some nonsesnse) I decoupled writing
of sections from a class.
SectionWriter: This is just the ELFT templated implementation of
SectionVisitor. Many classes now have this class as a friend so that the
writing methods in this class can write out private data.
ELFWriter: This is the Writer that outputs to ELF
BinaryWriter: This is the Writer that outputs to Binary
ElfType: Because the ELF Type is not a part of the Object anymore we need a way
to construct the correct default Writer based on properties of the Reader. This
enum just keeps track of the ELF type of the input so it can be used as the
default output type as well.
Object has correspondingly undergone some serious changes as well. It now has
more generic methods for building and manipulating ELF binaries. This interface
makes ELFBuilder easy enough to use and will make the BinaryReader/Builder easy
to create as well. Most changes in this diff are cosmetic and deal with the
fact that a method has been moved from one class to another or a change from a
pointer to a reference. Almost no changes should result in a functional
difference (this is after all a refactor). One minor functional change was made
and the result can be seen in remove-shstrtab-error.test. The fact that it
fails hasn't changed but the error message has changed because that failure is
detected at a later point in the code now (because WriteSectionHeaders is a
property of the ElfWriter *not* a property of the Object). I'd say roughly
80-90% of this code is cosmetically different, 10-19% is different but
functionally the same, and 1-5% is functionally different despite not causing a
change in tests.
Differential Revision: https://reviews.llvm.org/D42222
llvm-svn: 323480
For sections with different virtual and physical addresses, alignment and
placement in the output binary should be based on the physical address.
Ran into this problem with a bare metal ARM project where llvm-objcopy added a
lot of zero-padding before the .data section that had differing addresses. GNU
objcopy did not add the padding, and after this fix, neither does llvm-objcopy.
Update a test case so a section has different physical and virtual addresses.
Fixes B35708
Authored By: Owen Shaw (owenpshaw)
Differential Revision: https://reviews.llvm.org/D41619
llvm-svn: 323144
This change adds support in llvm-objcopy for GNU objcopy's --localize-hidden
option. This option changes every hidden or internal symbol into a local symbol.
llvm-svn: 321884
I have no clue how this was missed when symbol table support was added. This
change ensures that the visibility of symbols is preserved by default.
llvm-svn: 321681
This change adds support for adding progbits sections with contents from a file
Differential Revision: https://reviews.llvm.org/D41212
llvm-svn: 321047
Overtime some non-clang formatted code has creeped into llvm-objcopy. This
patch fixes all of that.
Differential Revision: https://reviews.llvm.org/D41262
llvm-svn: 320856
This change adds support for the --only-keep option and the -j alias as well.
A common use case for these being used together is to dump a specific section's
data. Additionally the --keep option is added (GNU objcopy doesn't have this)
to avoid removing a bunch of things. This allows people to err on the side of
stripping aggressively and then to keep the specific bits that they need for
their application.
Differential Revision: https://reviews.llvm.org/D39021
llvm-svn: 319467
GNU's --strip-all doesn't strip as aggressively as it could in general.
Currently llvm-objcopy copies the exact behavoir of GNU's --strip-all.
eu-strip is used as a drop in replacement for GNU strip/objcopy in many many
places without issue. eu-strip removes non-allocated sections and keeps
.gnu.warning* sections. Because --strip-all will likely be the most widely
used stripping option we should make --strip-all as aggressive as it can safely
be. Since we have evidence from eu-strip that this is a safe option we should
allow it. For those that might still have an issue afterwards I've added
--strip-all-gnu as an exact drop in replacement for GNU's --strip-all as well.
llvm-svn: 319071
The original -O binary implementation just copied segment data from the
object and dumped it into a file. This doesn't take into account any
operations performed on objects such as section removal. GNU objcopy has
some specific behavior that we'd also like to respect. For instance
using -O binary and -j <some_section> will dump <some_section> to a
file. This change implements GNU objcopy style -O binary to as close of
an approximation as I can determine.
Differential Revision: https://reviews.llvm.org/D39713
llvm-svn: 318324
I was being inconsistent with the way I was capitalizing help messages
for command line options. Additionally --remove-section wasn't using
value_desc even though it benefited from it.
Differential Revision: https://reviews.llvm.org/D39978
llvm-svn: 318190
This change adds a new flag not present in GNU objcopy that we call
--strip-non-alloc.
Differential Revision: https://reviews.llvm.org/D39926
llvm-svn: 318168
We haven't been supporting anything but ELF64LE since the start. Luckily
this was always accounted for and the change is pretty trivial. B35281
requests this change for ELF32LE. This change adds support for ELF32LE,
ELF64BE, and ELF32BE with all supported features that already existed
for ELF64LE.
Differential Revision: https://reviews.llvm.org/D39977
llvm-svn: 318166
Many projects use this option. There are two ways to use it. You can
either a) Just use --strip-debug and keep the old file with debug
content or b) you can use --strip-debug, --only-keep-debug, and
--add-gnu-debuglink all in conjunction to create two separate files, the
stripped file and the debug file. --only-keep-debug is more complicated
than --strip-debug because it keeps the section headers without keeping
section contents. That's not really supported by llvm-objcopy at the
moment but I plan on adding it. So this change just supports a) and
options to support b) will come soon.
Differential Revision: https://reviews.llvm.org/D39919
llvm-svn: 318094
This change adds a slightly less extreme form of stripping. It should
remove any section that starts with ".debug" and should remove any
symbol table or relocations. In general this strips out most of the
stuff you don't need to execute but leaves a number of things around.
This behavior has been designed to be compatible with GNU strip/objcopy
--strip-all so that anywhere you currently use --strip-all you should be
able to use llvm-objcopy as a drop in replacement.
Differential Revision: https://reviews.llvm.org/D39769
llvm-svn: 318092
Just aligning segment offsets to segment alignment is incorrect and also
wastes more space than is needed. The requirement is that p_offset ==
p_addr modulo p_align *not* that p_offset == 0 modulo p_align. Generally
speaking we've been using p_addr == 0 modulo p_align. In fact yaml2obj
can't even produce a valid situation which causes llvm-objcopy to
produce incorrect results because alignment and offset were both
inherited from the sections the program header covers. This change fixes
this bad behavior in llvm-objcopy.
Differential Revision: https://reviews.llvm.org/D39132
llvm-svn: 317284
The LLVM tools can be used as a replacement for binutils, in which case
it's convenient to create symlinks with the binutils names. Add support
for these symlinks in the build system. As with any other llvm tool
symlinks, the user can limit the installed symlinks by only adding the
desired ones to `LLVM_TOOLCHAIN_TOOLS`.
Differential Revision: https://reviews.llvm.org/D39530
llvm-svn: 317272
This reverts commit 4e4ee1c507e2707bb3c208e1e1b6551c3015cbf5.
This is failing due to some code that isn't built on MSVC
so I didn't catch. Not immediately obvious how to fix this
at first glance, so I'm reverting for now.
llvm-svn: 315536
There's a lot of misuse of Twine scattered around LLVM. This
ranges in severity from benign (returning a Twine from a function
by value that is just a string literal) to pretty sketchy (storing
a Twine by value in a class). While there are some uses for
copying Twines, most of the very compelling ones are confined
to the Twine class implementation itself, and other uses are
either dubious or easily worked around.
This patch makes Twine's copy constructor private, and fixes up
all callsites.
Differential Revision: https://reviews.llvm.org/D38767
llvm-svn: 315530
ubsan caught an issue I made where I was converting a null pointer to a
reference.
elf utils implements a particularly extreme form of stripping that I'd
like to support. eu-strip has an option called "strip-sections" that
removes all section headers and leaves only program headers and the
segment data. I have implemented this option partly as a test but mainly
because in Fuchsia we would like to use this option to minimize the size
of our executables. The other strip options that are on my list include
--strip-all and --strip-debug. This is a preliminary implementation that
I'd like to start using in Fuchsia builds if possible. This change
implements such a stripping option for llvm-objcopy
Differential Revision: https://reviews.llvm.org/D38335
llvm-svn: 315484
elf utils implements a particularly extreme form of stripping that I'd
like to support. eu-strip has an option called "strip-sections" that
removes all section headers and leaves only program headers and the
segment data. I have implemented this option partly as a test but mainly
because in Fuchsia we would like to use this option to minimize the size
of our executables. The other strip options that are on my list include
--strip-all and --strip-debug. This is a preliminary implementation that
I'd like to start using in Fuchsia builds if possible. This change
implements such a stripping option for llvm-objcopy
Differential Revision: https://reviews.llvm.org/D38335
llvm-svn: 315412
This change adds the ability to use the "-R"/"-remove-section" option
multiple times.
Differential Revision: https://reviews.llvm.org/D38332
llvm-svn: 315385
If a Section had Type SHT_STRTAB (which could happen if you had a
.dynstr section) it was possible to cast Section to StringTableSection
and get away with any operation that was supported by SectionBase
without it being noticed. This change makes this bug easier to notice
and fixes it where it occurred. It also made me realize that there was
some duplication of efforts in the loop that calls ::initialize. These
issues are all fixed by this change.
Differential Revision: https://reviews.llvm.org/D38329
llvm-svn: 315372
This change adds support for removing sections using the -R field (as
GNU objcopy does as well). This change should let us add many helpful
tests and is a proper stepping stone for adding more general kinds of
stripping.
Differential Revision: https://reviews.llvm.org/D38260
llvm-svn: 315346
