Summary: I had added support for compressing dwarf sections in a prior commit,
this one adds support for decompressing. Usage is:
llvm-objcopy --decompress-debug-sections input.o output.o
Reviewers: jakehehrlich, jhenderson, alexshap
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D51841
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343451 91177308-0d34-0410-b5e6-96231b3b80d8
Submitted on behalf of Armando Montanez (amontanez@google.com).
Objects with unused program headers copied by objcopy would always have
nonzero values for program header offset and program header entry size.
While technically valid, this atypical behavior triggers warnings in some
tools. This change sets the two fields to zero when the program header is
unused, better fitting the general expectations for unused program header
data.
Section headers behaved somewhat similarly (though only with the entry size),
and are fixed in this revision as well.
Differential Revision: https://reviews.llvm.org/D51961
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342065 91177308-0d34-0410-b5e6-96231b3b80d8
Third Attempt:
- Alignment issues resolved.
- zlib::isAvailable() detected.
- ArrayRef misuse fixed.
Usage:
llvm-objcopy --compress-debug-sections=zlib foo.o
llvm-objcopy --compress-debug-sections=zlib-gnu foo.o
In both cases the debug section contents is compressed with zlib. In the GNU
style case the header is the "ZLIB" magic string followed by the uint64 big-
endian decompressed size. In the non-GNU mode the header is the
Elf(32|64)_Chdr.
Decompression support is coming soon.
Differential Revision: https://reviews.llvm.org/D49678
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341635 91177308-0d34-0410-b5e6-96231b3b80d8
Second Attempt. Alignment issues resolved. zlib::isAvailable() detected.
Usage:
llvm-objcopy --compress-debug-sections=zlib foo.o
llvm-objcopy --compress-debug-sections=zlib-gnu foo.o
In both cases the debug section contents is compressed with zlib. In the GNU
style case the header is the "ZLIB" magic string followed by the uint64 big-
endian decompressed size. In the non-GNU mode the header is the
Elf(32|64)_Chdr.
Decompression support is coming soon.
Differential Revision: https://reviews.llvm.org/D49678
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341607 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Fixes the error "Link field value 0 in section .rela.plt is invalid" when copying/stripping certain binaries. Minimal repro:
```
$ cat /tmp/a.c
int main() { return 0; }
$ clang -static /tmp/a.c -o /tmp/a
$ llvm-strip /tmp/a -o /tmp/b
llvm-strip: error: Link field value 0 in section .rela.plt is invalid.
```
Reviewers: jakehehrlich, alexshap
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51493
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341419 91177308-0d34-0410-b5e6-96231b3b80d8
Usage:
llvm-objcopy --compress-debug-sections=zlib foo.o
llvm-objcopy --compress-debug-sections=zlib-gnu foo.o
In both cases the debug section contents is compressed with zlib. In the GNU
style case the header is the "ZLIB" magic string followed by the uint64 big-
endian decompressed size. In the non-GNU mode the header is the
Elf(32|64)_Chdr.
Decompression support is coming soon.
Differential Revision: https://reviews.llvm.org/D49678
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341342 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The -I (--input-target) and -B (--binary-architecture) flags exist but are currently silently ignored. This adds support for -I binary for architectures i386, x86-64 (and alias i386:x86-64), arm, aarch64, sparc, and ppc (powerpc:common64). This is largely based on D41687.
This is done by implementing an additional subclass of Reader, BinaryReader, which works by interpreting the input file as contents for .data field, sets up a synthetic header, and adds additional sections/symbols (e.g. _binary__tmp_data_txt_start).
Reviewers: jakehehrlich, alexshap, jhenderson, javed.absar
Reviewed By: jhenderson
Subscribers: jyknight, nemanjai, kbarton, fedor.sergeev, jrtc27, kristof.beyls, paulsemel, llvm-commits
Differential Revision: https://reviews.llvm.org/D50343
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340070 91177308-0d34-0410-b5e6-96231b3b80d8
Anywhere in tools/llvm-objcopy where functions or classes are not referenced
outside of a given file, we change things to make the function or class static
or put inside an anonymous namespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337220 91177308-0d34-0410-b5e6-96231b3b80d8
The class Object contains std::shared_ptr<MemoryBuffer> OwnedData
which is not used anywhere. Besides avoiding two stage initialization
the motivation to remove it comes from the plan to add (currently missing) support
for static libraries.
NFC.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D47855
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334217 91177308-0d34-0410-b5e6-96231b3b80d8
Per discussion on the generic-abi mailing list:
https://groups.google.com/forum/#!topic/generic-abi/MPr8TVtnVn4
An object file manipulation tool must either write out a symbol
table with the same number of entries as the original symbol table
and in the same order, or if this is impossible, refuse to operate
on the object file if it has unrecognized sections that are linked
to the symtab section. However, existing tools (namely GNU strip,
GNU objcopy and ld.{bfd,gold,lld} -r) do not comply with this at
present: they change symbol table indexes and set sh_link to 0 on
the unrecognized symtab-linked sections.
We intend to use the latter as a (temporary) signal that a tool has
operated on a proposed new symtab-linked section and invalidated the
symbol table indexes. However, llvm-objcopy currently keeps sh_link
pointing to the new symtab section. This patch changes llvm-objcopy
to set sh_link to 0 to match the behaviour of the other tools.
Differential Revision: https://reviews.llvm.org/D47404
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333581 91177308-0d34-0410-b5e6-96231b3b80d8
This diff fixes sh_link for various types of sections
(i.e. for SHT_ARM_EXIDX, SHT_HASH). In particular, this change enables us
to use llvm-objcopy with clang -gsplit-dwarf for the target android-arm.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D45851
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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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328143 91177308-0d34-0410-b5e6-96231b3b80d8
Temporarily revert r328012 (since it broke down the big-endian bots),
will resubmit an updated version later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328024 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328012 91177308-0d34-0410-b5e6-96231b3b80d8
Not all build bots have unzip which I used in a test.
This reverts commit 0b1f26d39ea42dd3716b525fbc8c78d8c7bb4479.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326941 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326940 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325528 91177308-0d34-0410-b5e6-96231b3b80d8
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
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Somehow I reverted changes I made in a previous Reland. This change re-relands
unconfusing a varible name with a type name.
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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.
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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
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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
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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.
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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.
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