This patch adds support of the following llvm-objcopy flags for MachO:
- `--globalize-symbol`, `--globalize-symbols`,
- `--keep-global-symbol`, `-G`, `--keep-global-symbols`,
- `--localize-symbol`, `-L`, `--localize-symbols`,
- `--skip-symbol`, `--skip-symbols`.
Code in `updateAndRemoveSymbols` for MachO
is kept similar to its version for ELF.
Fixes#120894
--change-section address and its alias --adjust-section-vma allows
modification
of section addresses in a relocatable file. This used to be used, for
example,
in Fiasco microkernel.
On a relocatable file this option behaves the same as GNU objcopy, apart
from
the fact that it does not issue any warnings, for example, when an
argument is
not used.
GNU objcopy does not produce an error when passed an executable file but
the
usecase for this is not clear, and the behaviour is inconsistent. The
idea of
GNU objcopy --change-section-address is that the option should change
both LMA
and VMA in an executable file. Since this patch does not implement
executable
file support, only VMA is changed.
llvm-objcopy did not support change-section-lma argument.
This patch adds support for a use case of change-section-lma, that is
shifting load address of all sections by the same offset. This seems to
be the only practical use case of change-section-lma, found in other
software such as Zephyr RTOS's build system.
This is an option that could possibly be supported in some other than
ELF formats, however this change only implements it for ELF. When used
with other formats an error message is raised.
In comparison, the behavior of GNU objcopy is inconsistent. For some ELF
files it behaves the same as described above. For others, it copies the
file without modifying the p_paddr fields when it would be expected. In
some experiments it modifies arbitrary fields in section or program
headers. It is unclear what exactly determines this.
The executable file generated by yaml2obj in this test is not parsable
by GNU objcopy. With Machine set to EM_AARCH64, the file can be parsed
and the first test in the test file completes with 0 exit code. However,
the result is rather arbitrary. AArch64 GNU objcopy subtracts 0x1000
from p_filesz and p_memsz of the first LOAD section and 0x1000 from
p_offset of the second LOAD section. It does not look meaningful.
--compress-sections is similar to --compress-debug-sections but applies
to arbitrary sections.
* `--compress-sections <section>=none`: decompress sections
* `--compress-sections <section>=[zlib|zstd]`: compress sections with zlib/zstd
Like `--remove-section`, the pattern is by default a glob, but a regex
when --regex is specified.
For `--remove-section` like options, `!` prevents matches and is not
dependent on ordering (see `ELF/wildcard-syntax.test`). Since
`--compress-sections a=zlib --compress-sections a=none` naturally allows
overriding, having an order-independent `!` would be confusing.
Therefore, `!` is disallowed.
Sections within a segment are effectively immutable. Report an error for
an attempt to (de)compress them. `SHF_ALLOC` sections in a relocatable
file can be compressed, but linkers usually reject them.
Note: Before this patch, a compressed relocation section is recognized
as a `RelocationSectionBase` as well and `removeSections` `!ToRemove(*ToRelSec)`
may incorrectly interpret a `CompressedSections` as `RelocationSectionBase`,
leading to ubsan failure for the new test. Fix this by setting
`OriginalFlags` in CompressedSection::CompressedSection.
Link: https://discourse.llvm.org/t/rfc-compress-arbitrary-sections-with-ld-lld-compress-sections/71674
Pull Request: https://github.com/llvm/llvm-project/pull/85036
This reverts commit 9e3b64b9f95aadf57568576712902a272fe66503.
Reason: Broke the UBSan buildbot. See the comments in the pull request
(https://github.com/llvm/llvm-project/pull/85036) for more information.
--compress-sections is similar to --compress-debug-sections but applies
to arbitrary sections.
* `--compress-sections <section>=none`: decompress sections
* `--compress-sections <section>=[zlib|zstd]`: compress sections with zlib/zstd
Like `--remove-section`, the pattern is by default a glob, but a regex
when --regex is specified.
For `--remove-section` like options, `!` prevents matches and is not
dependent on ordering (see `ELF/wildcard-syntax.test`). Since
`--compress-sections a=zlib --compress-sections a=none` naturally allows
overriding, having an order-independent `!` would be confusing.
Therefore, `!` is disallowed.
Sections within a segment are effectively immutable. Report an error for
an attempt to (de)compress them. `SHF_ALLOC` sections in a relocatable
file can be compressed, but linkers usually reject them.
Link: https://discourse.llvm.org/t/rfc-compress-arbitrary-sections-with-ld-lld-compress-sections/71674
Pull Request: https://github.com/llvm/llvm-project/pull/85036
Add --skip-symbol and --skip-symbols options that allow to skip symbols
when executing other options that can change the symbol's name, binding
or visibility, similar to an existing option --keep-symbol that keeps a
symbol from being removed by other options.
Add options --set-symbol-visibility and --set-symbols-visibility to
manually change the visibility of symbols.
There is already an option to set the visibility of newly added symbols
via --add-symbol and --new-symbol-visibility. This option will allow to
change the visibility of already existing symbols.
https://reviews.llvm.org/D63820 added
llvm/docs/CommandGuide/llvm-objcopy.rst with clearer semantics, e.g.
```
Read a list of names from the file <filename> and mark defined symbols with those names as global in the output
instead of the help message
Read a list of symbols from <filename> and marks them global" (omits "defined")
Rename sections called <old> to <new> in the output
instead of the help message
Rename a section from old to new (multiple sections may be named <old>
```
Sync the help messages to incorporate the CommandGuide improvement.
While here, switch to the conventional imperative sentences for a few
options. Additionally, mark some options as grp_coff or grp_macho.
`--gap-fill <value>` fills the gaps between sections with a specified
8-bit value, instead of zero.
`--pad-to <address>` pads the output binary up to the specified load
address, using the 8-bit value from `--gap-fill` or zero.
These options are only supported for ELF input and binary output.
Currently, objcopy cannot set the new flag SHF_X86_64_LARGE. This change introduces the named flag "large" which translates to that section flag.
An "invalid argument" error is produced if a user attempts to set the flag on an architecture other than X86_64.
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D153262
This reverts commit 19dc3cff0f771bb8933136ef68e782553e920d04.
This reverts commit 5b19a1f8e88da9ec92b995bfee90043795c2c252.
This reverts commit 9397648ac8ad192f7e6e6a8e6894c27bf7e024e9.
This reverts commit 10842b44759f987777b08e7714ef77da2526473a.
Breaks the GCC build, as reported here:
https://reviews.llvm.org/D130506#3776415
This reverts commit c26dc2904b95b3685d883e760e84046ea6c33d7f.
The new Zstd dispatch has an ongoing design discussion related to https://reviews.llvm.org/D130516#3688123 .
Revert for now before it is resolved.
The request is mentioned on D129053. I feel that having this functionality is
mildly useful (not strong).
* Rename .ctors to .init_array and change sh_type to SHT_INIT_ARRAY (GNU objcopy
detects the special name but we don't).
* Craft tests for a new SHT_LLVM_* extension
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D129337
I noticed that when --update-section was added to llvm-objcopy it was
not added to the command guide, see
25bcd94234530955c58c6530a9271c813827637c. This change adds it to the
docs and updates the help text.
Differential Revision: https://reviews.llvm.org/D122907
Although we moved to Github Issues. The bug report message refers to
Bugzilla still. This patch tries to update these URLs.
Reviewed By: MaskRay, Quuxplusone, jhenderson, libunwind, libc++
Differential Revision: https://reviews.llvm.org/D116351
This change is to keep the help text and command guide of objcopy in
tandem.
- In the help output the options --rename-section and
--set-section-flags were missing the flag exclude, which is found in
the command guide.
- In the command guide the alias -G for --keep-global-symbol was
missing, which is found in the help output.
Differential Revision: https://reviews.llvm.org/D110340
This diff introduces --keep-undefined in llvm-objcopy/llvm-strip for Mach-O
which makes the tools preserve undefined symbols.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D97040
The help text and documentation for the --discard-all option failed to
mention that the option also causes the removal of debug sections. This
change fixes both for both llvm-objcopy and llvm-strip.
Reviewed by: MaskRay
Differential Revision: https://reviews.llvm.org/D97662
The few options are niche. They solved a problem which was traditionally solved
with more shell commands (`llvm-readelf -n` fetches the Build ID. Then
`ln` is used to hard link the file to a directory derived from the Build ID.)
Due to limitation, they are no longer used by Fuchsia and they don't appear to
be used elsewhere (checked with Google Search and Debian Code Search). So delete
them without a transition period.
Announcement: https://lists.llvm.org/pipermail/llvm-dev/2021-February/148446.html
Differential Revision: https://reviews.llvm.org/D96310
The --output-target documentation has slightly rotted, as the default is
no longer purely based on the input file format, but also the value of
--input-target. This patch updates the documentation to make this
explicit.
Reviewed by: MaskRay, alexshap
Differential Revision: https://reviews.llvm.org/D79318
The sub-heading used to contain the --only-keep-debug switch as that
switch wasn't implemented for ELF at one point. Since the switch is now
in the generic options section, and there are no other options in this
sub-heading, it is pointless and can be deleted.
The parsing error tests in ELF/redefine-symbols.test are not specific to ELF.
Move them to redefine-symbols.test.
Add COFF/redefine-symbols.test for COFF specific tests.
Also fix the documentation regarding --redefine-syms: the old and new
names are separated by whitespace, not an equals sign.
Reviewed By: mstorsjo
Differential Revision: https://reviews.llvm.org/D70036
--only-keep-debug produces a debug file as the output that only
preserves contents of sections useful for debugging purposes (the
binutils implementation preserves SHT_NOTE and non-SHF_ALLOC sections),
by changing their section types to SHT_NOBITS and rewritting file
offsets.
See https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
The intended use case is:
```
llvm-objcopy --only-keep-debug a a.dbg
llvm-objcopy --strip-debug a b
llvm-objcopy --add-gnu-debuglink=a.dbg b
```
The current layout algorithm is incapable of deleting contents and
shrinking segments, so it is not suitable for implementing the
functionality.
This patch adds a new algorithm which assigns sh_offset to sections
first, then modifies p_offset/p_filesz of program headers. It bears a
resemblance to lld/ELF/Writer.cpp.
Reviewed By: jhenderson, jakehehrlich
Differential Revision: https://reviews.llvm.org/D67137
This works around a bug in Debian's patchset for glibc. The bug is
described in detail in the upstream debian bug:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=943798, but the short
version of it is that glibc on any Debian based distro don't load
libraries unless it has a .ARM.attribute section.
Reviewed by: jhenderson, rupprecht, MaskRay, jakehehrlich
Differential Revision: https://reviews.llvm.org/D69188
Patch by Tobias Hieta.
Summary: GNU objcopy accepts the --wildcard flag to allow wildcard matching on symbol-related flags. (Note: it's implicitly true for section flags).
The basic syntax is to allow *, ?, \, and [] which work similarly to how they work in a shell. Additionally, starting a wildcard with ! causes that wildcard to prevent it from matching a flag.
Use an updated GlobPattern in libSupport to handle these patterns. It does not fully match the `fnmatch` used by GNU objcopy since named character classes (e.g. `[[:digit:]]`) are not supported, but this should support most existing use cases (mostly just `*` is what's used anyway).
Reviewers: jhenderson, MaskRay, evgeny777, espindola, alexshap
Reviewed By: MaskRay
Subscribers: nickdesaulniers, emaste, arichardson, hiraditya, jakehehrlich, abrachet, seiya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66613
llvm-svn: 375169
