Summary:
Some flags accepted by --set-section-flags and --rename-section can change a SHT_NOBITS section to a SHT_PROGBITS section. Note that none of them can change a SHT_PROGBITS to SHT_NOBITS.
The full list (found via experimentation of individually setting each flag) that does this is: contents, load, noload, code, data, rom, and debug.
This was found by testing llvm-objcopy with the gnu binutils test suite, specifically this test case: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=binutils/testsuite/binutils-all/copy-1.d;h=f2b0d9e90df738c2891b4d5c7b62f62894b556ca;hb=HEAD
Reviewers: jhenderson, grimar, jakehehrlich, alexshap, espindola
Reviewed By: jhenderson
Subscribers: emaste, arichardson, MaskRay, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59958
llvm-svn: 357492
This patch fixes https://bugs.llvm.org/show_bug.cgi?id=41293 and
https://bugs.llvm.org/show_bug.cgi?id=41045. llvm-objcopy assumed that
it could always read a section header string table. This isn't the case
when the sections were previously all stripped, and the e_shstrndx field
was set to 0. This patch fixes this. It also fixes a double space in an
error message relating to this issue, and prevents llvm-objcopy from
adding extra space for non-existent section headers, meaning that
--strip-sections on the output of a previous --strip-sections run
produces identical output, simplifying the test.
Reviewed by: rupprecht, grimar
Differential Revision: https://reviews.llvm.org/D59989
llvm-svn: 357475
Summary:
BTW, STLExtras.h provides llvm::size() which is similar to std::size()
for random access iterators. However, if we prefer qualified
llvm::size(), the member function .size() will be more convenient.
Reviewers: jhenderson, jakehehrlich, rupprecht, grimar, alexshap, espindola
Reviewed By: grimar
Subscribers: emaste, arichardson, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60028
llvm-svn: 357347
This is a fix for https://bugs.llvm.org/show_bug.cgi?id=40007.
Idea is to swap the order of stripping. So that we strip sections before
symbols what allows us to strip relocation sections without emitting
the error about relative symbols.
Differential revision: https://reviews.llvm.org/D59763
llvm-svn: 357017
llvm-objcopy previously knew nothing about data in segments that wasn't
covered by section headers, meaning that it wrote zeroes instead of what
was there. As it is possible for this data to be useful to the loader,
this patch causes llvm-objcopy to start preserving this data. Data in
sections that are explicitly removed continues to be written as zeroes.
This fixes https://bugs.llvm.org/show_bug.cgi?id=41005.
Reviewed by: jakehehrlich, rupprecht
Differential Revision: https://reviews.llvm.org/D59483
llvm-svn: 356919
The idea of the patch is about to move out the code to a new
helper static functions (to reduce the size of 'handleArgs' and to
isolate the parts of it's logic).
Differential revision: https://reviews.llvm.org/D59762
llvm-svn: 356889
Fix: r356853 + set AddressAlign to 4 in
Inputs/compress-debug-sections.yaml for the new group section introduced.
Original commit message:
Currently, llvm-objcopy incorrectly handles compression and decompression of the
sections from COMDAT groups, because we do not implement the
replaceSectionReferences for this type of the sections.
The patch does that.
Differential revision: https://reviews.llvm.org/D59638
llvm-svn: 356856
This patch fixes the reason of ubsan failure (UB detected)
happened after landing the D59638 (I had to revert it).
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-ubsan/builds/11760/steps/check-llvm%20ubsan/logs/stdio)
Problem is the following. Our implementation of GroupSection assumes that
its address is 4 bytes aligned when writes it:
template <class ELFT>
void ELFSectionWriter<ELFT>::visit(const GroupSection &Sec) {
ELF::Elf32_Word *Buf =
reinterpret_cast<ELF::Elf32_Word *>(Out.getBufferStart() + Sec.Offset);
...
But the test case for D59638 did not set AddressAlign in YAML. So address was
not 4 bytes aligned since Sec.Offset was odd. That triggered the issue.
This patch teaches llvm-objcopy to report an error for such sections (which should
not met in reality), what is better than having UB.
Differential revision: https://reviews.llvm.org/D59695
llvm-svn: 356853
Currently, llvm-objcopy incorrectly handles compression and decompression of the
sections from COMDAT groups, because we do not implement the
replaceSectionReferences for this type of the sections.
The patch does that.
Differential revision: https://reviews.llvm.org/D59638
llvm-svn: 356738
GNU objcopy can support output formats like elf32-i386-freebsd and
elf64-x86-64-freebsd. The only difference from their regular non-freebsd
counterparts that I have observed is that the freebsd versions set the
OS/ABI field to ELFOSABI_FREEBSD. This patch sets the OS/ABI field
according based on the format whenever --output-format is specified.
Reviewed by: rupprecht, grimar
Differential Revision: https://reviews.llvm.org/D59645
llvm-svn: 356737
If the compression was used and we had a symbol not involved in relocation,
we never updated its section and it was silently removed from the output.
Differential revision: https://reviews.llvm.org/D59542
llvm-svn: 356554
This change makes linking into .build-id atomic and safe to use.
Some users under particular workflows are reporting that this races
more than half the time under particular conditions.
llvm-svn: 356404
This fixes the https://bugs.llvm.org/show_bug.cgi?id=40980.
Previously if string optimization occurred as a result of
StringTableBuilder's finalize() method, the size wasn't updated.
This hopefully also makes the interaction between sections during finalization
processes a bit more clear.
Differential revision: https://reviews.llvm.org/D59488
llvm-svn: 356371
For ELF, we accept but ignore --only-keep-debug. Do the same for llvm-strip.
COFF does implement this, so update the test that it is supported.
llvm-svn: 356207
This patch changes llvm-objcopy's behaviour to not strip sections that
are in segments, if they otherwise would be due to a stripping operation
(--strip-all, --strip-sections, --strip-non-alloc). This preserves the
segment contents. It does not change the behaviour of --strip-all-gnu
(although we could choose to do so), because GNU objcopy's behaviour in
this case seems to be to strip the section, nor does it prevent removing
of sections in segments with --remove-section (if a user REALLY wants to
remove a section, we should probably let them, although I could be
persuaded that warning might be appropriate). Tests have been added to
show this latter behaviour.
This fixes https://bugs.llvm.org/show_bug.cgi?id=41006.
Reviewed by: grimar, rupprecht, jakehehrlich
Differential Revision: https://reviews.llvm.org/D59293
This is a reland of r356129, attempting to fix greendragon failures
due to a suspected compatibility issue with od on the greendragon bots
versus other versions.
llvm-svn: 356136
This patch changes llvm-objcopy's behaviour to not strip sections that
are in segments, if they otherwise would be due to a stripping operation
(--strip-all, --strip-sections, --strip-non-alloc). This preserves the
segment contents. It does not change the behaviour of --strip-all-gnu
(although we could choose to do so), because GNU objcopy's behaviour in
this case seems to be to strip the section, nor does it prevent removing
of sections in segments with --remove-section (if a user REALLY wants to
remove a section, we should probably let them, although I could be
persuaded that warning might be appropriate). Tests have been added to
show this latter behaviour.
This fixes https://bugs.llvm.org/show_bug.cgi?id=41006.
Reviewed by: grimar, rupprecht, jakehehrlich
Differential Revision: https://reviews.llvm.org/D59293
llvm-svn: 356129
error() was previously cleaned up from CopyConfig, but new uses were introduced.
This also tweaks the error message for --add-symbol to report all invalid flags.
llvm-svn: 356105
When --compress-debug-sections is given,
llvm-objcopy removes the uncompressed sections and adds compressed to the section list.
This makes all the pointers to old sections to be outdated.
Currently, code already has logic for replacing the target sections of the relocation
sections. But we also have to update the relocations by themselves.
This fixes https://bugs.llvm.org/show_bug.cgi?id=40885.
Differential revision: https://reviews.llvm.org/D58960
llvm-svn: 355821
We should create CompressedSection only if the section has SHF_COMPRESSED flag
or it's name starts from '.zdebug'.
Currently, we create it if section's data starts from ZLIB signature.
Differential revision: https://reviews.llvm.org/D59018
llvm-svn: 355501
When --compress-debug-sections is given, llvm-objcopy do not compress
sections that have "ZLIB" header in data. Normally this signature is used
in zlib-gnu compression format. But if zlib-gnu used then the name of the compressed
section should start from .z* (e.g .zdebug_info). If it does not, then it is not
a zlib-gnu format and section should be treated as a normal uncompressed section.
Differential revision: https://reviews.llvm.org/D58908
llvm-svn: 355399
If zlib is not available, and --compress-debug-sections is passed,
we want to report an error. Currently, it is only reported for
--compress_debug_sections= form of the option.
Fixes the https://bugs.llvm.org/show_bug.cgi?id=40886.
I do not think there is a way to write a test for this.
Differential revision: https://reviews.llvm.org/D58909
llvm-svn: 355391
Summary:
This removes calls to `error()`/`reportError()` in the main driver (llvm-objcopy.cpp) as well as the associated argv-parsing (CopyConfig.cpp). `logAllUnhandledErrors()` is now the main way to print errors.
There are still a few uses from within the per-arch drivers, so we can't delete them yet... but almost!
Reviewers: jhenderson, alexshap, espindola
Reviewed By: jhenderson
Subscribers: emaste, arichardson, jakehehrlich, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58316
llvm-svn: 354600
Summary:
Removing a large number of sections from a file with a lot of symbols can have abysmal (i.e. O(n^2)) performance, e.g. when running `--only-section` to extract one section out of a large file.
This comes from iterating over all symbols in the symbol table each time we remove a section, to remove references to the section we just removed.
Instead, do just one pass of symbol removal by passing a hash set of all the sections we'd like to remove references to.
This fixes a regression when running llvm-objcopy -j <one section> on an object file with many sections and symbols -- on my machine, running `objcopy -j .keep_me huge-input.o /tmp/foo.o` takes .3s with GNU objcopy, 1.3s with an updated llvm-objcopy, and 7+ minutes with llvm-objcopy prior to this patch.
Reviewers: MaskRay, jhenderson, jakehehrlich, alexshap, espindola
Reviewed By: MaskRay, jhenderson
Subscribers: echristo, emaste, arichardson, mgrang, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58296
llvm-svn: 354597
A fallible iterator is one whose increment or decrement operations may fail.
This would usually be supported by replacing the ++ and -- operators with
methods that return error:
class MyFallibleIterator {
public:
// ...
Error inc();
Errro dec();
// ...
};
The downside of this style is that it no longer conforms to the C++ iterator
concept, and can not make use of standard algorithms and features such as
range-based for loops.
The fallible_iterator wrapper takes an iterator written in the style above
and adapts it to (mostly) conform with the C++ iterator concept. It does this
by providing standard ++ and -- operator implementations, returning any errors
generated via a side channel (an Error reference passed into the wrapper at
construction time), and immediately jumping the iterator to a known 'end'
value upon error. It also marks the Error as checked any time an iterator is
compared with a known end value and found to be inequal, allowing early exit
from loops without redundant error checking*.
Usage looks like:
MyFallibleIterator I = ..., E = ...;
Error Err = Error::success();
for (auto &Elem : make_fallible_range(I, E, Err)) {
// Loop body is only entered when safe.
// Early exits from loop body permitted without checking Err.
if (SomeCondition)
return;
}
if (Err)
// Handle error.
* Since failure causes a fallible iterator to jump to end, testing that a
fallible iterator is not an end value implicitly verifies that the error is a
success value, and so is equivalent to an error check.
Reviewers: dblaikie, rupprecht
Subscribers: mgorny, dexonsmith, kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57618
llvm-svn: 353237
Summary: Use StringSaver/BumpPtrAlloc when parsing lines from --keep-global-symbols files. This allows us to consistently use StringRef for driver options, which avoids copying the full strings for each object copied, as well as simplifies part of D57517.
Reviewers: jhenderson, evgeny777, alexshap
Subscribers: jakehehrlich
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57617
llvm-svn: 353068
This diff implements first bits for copying (without modification) MachO object files.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D54674
llvm-svn: 352944
Summary:
Replace some reportError() calls with error propagation that was missed from rL352625.
Note this also adds an error check during Archive iteration that was being hidden by a different error check before:
```
for (const Archive::Child &Child : Ar.children(Err)) {
Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
if (!ChildOrErr)
// This aborts, so Err is never checked
reportError(Ar.getFileName(), ChildOrErr.takeError());
```
Err is being checked after the loop, so during happy runs, everything is fine. But when reportError is changed to return the error instead of aborting, the fact that Err is never checked is now noticed in tests that trigger an error during the loop.
Reviewers: jhenderson, dblaikie, alexshap
Reviewed By: dblaikie
Subscribers: llvm-commits, lhames, jakehehrlich
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57462
llvm-svn: 352888
Summary:
Include the symbol being defined in the list of requirements for using --localize-symbol.
This is used, for example, when someone is depending on two different projects that have the same (or close enough) method defined in each library, and using "-L sym" for a conflicting symbol in one of the libraries so that the definition from the other one is used. However, the library may have internal references to the symbol, which cause program crashes when those are used, i.e.:
```
$ cat foo.c
int foo() { return 5; }
$ cat bar.c
int foo();
int bar() { return 2 * foo(); }
$ cat foo2.c
int foo() { /* Safer implementation */ return 42; }
$ cat main.c
int bar();
int main() {
__builtin_printf("bar = %d\n", bar());
return 0;
}
$ ar rcs libfoo.a foo.o bar.o
$ ar rcs libfoo2.a foo2.o
# Picks the wrong foo() impl
$ clang main.o -lfoo -lfoo2 -L. -o main
# Picks the right foo() impl
$ objcopy -L foo libfoo.a && clang main.o -lfoo -lfoo2 -L. -o main
# Links somehow, but crashes at runtime
$ llvm-objcopy -L foo libfoo.a && clang main.o -lfoo -lfoo2 -L. -o main
```
Reviewers: jhenderson, alexshap, jakehehrlich, espindola
Subscribers: emaste, arichardson
Differential Revision: https://reviews.llvm.org/D57417
llvm-svn: 352767
Summary:
This adds support for the --discard-locals flag, which acts similarly to --discard-all, except it only applies to compiler-generated symbols (i.e. symbols starting with `.L` in ELF).
I am not sure about COFF local symbols: those appear to also use `.L` in most cases, but also use just `L` in other cases, so for now I am just leaving it unimplemented there.
Fixes PR36160
Reviewers: jhenderson, alexshap, jakehehrlich, mstorsjo, espindola
Reviewed By: jhenderson
Subscribers: llvm-commits, emaste, arichardson
Differential Revision: https://reviews.llvm.org/D57248
llvm-svn: 352626
Summary: Do some more error cleanup, removing some dependencies from llvm-objcopy's error/reportError in [ELF/COFF]Objcopy methods.
Reviewers: jhenderson, alexshap, jakehehrlich, mstorsjo, espindola
Subscribers: emaste, arichardson
Differential Revision: https://reviews.llvm.org/D57423
llvm-svn: 352625
Summary:
--set-section-flags is used to change the section flags (e.g. SHF_ALLOC) for given sections. The flags allowed are the same from the existing --rename-section=.old=.new[,flags] feature.
Additionally, make sure that --set-section-flag cannot be used with --rename-section (either the source or destination), since --rename-section accepts flags. This avoids ambiguity for something like "--rename-section=.foo=.bar,alloc --set-section-flag=.bar,code".
Reviewers: jhenderson, jakehehrlich, alexshap, espindola
Reviewed By: jhenderson, jakehehrlich
Subscribers: llvm-commits, emaste, arichardson
Differential Revision: https://reviews.llvm.org/D57198
llvm-svn: 352505
Summary: When using llvm-objcopy -O binary and the resulting file will be empty (e.g. removing the only section that would be written, or using --only-keep with a section that doesn't exist/isn't SHF_ALLOC), we crash because FileOutputBuffer expects Size > 0. Add a regression test, and change Buffer to open/truncate the output file in this case.
Reviewers: alexshap, jhenderson, jakehehrlich, espindola
Reviewed By: alexshap, jhenderson
Subscribers: jfb, llvm-commits, emaste, arichardson
Differential Revision: https://reviews.llvm.org/D56806
llvm-svn: 352371
This change adds an option -g to llvm-objcopy which is an alias for the existing option --strip-debug.
This fixes PR40003.
Reviewed by: alexshap
Differential Revision: https://reviews.llvm.org/D57217
llvm-svn: 352182
The aux symbols were stored in an opaque std::vector<uint8_t>,
with contents interpreted according to the rest of the symbol.
All aux symbol types but one fit in 18 bytes (sizeof(coff_symbol16)),
and if written to a bigobj, two extra padding bytes are written (as
sizeof(coff_symbol32) is 20). In the storage agnostic intermediate
representation, store the aux symbols as a series of coff_symbol16
sized opaque blobs. (In practice, all such aux symbols only consist
of one aux symbol, so this is more flexible than what reality needs.)
The special case is the file aux symbols, which are written in
potentially more than one aux symbol slot, without any padding,
as one single long string. This can't be stored in the same opaque
vector of fixed sized aux symbol entries. The file aux symbols will
occupy a different number of aux symbol slots depending on the type
of output object file. As nothing in the intermediate process needs
to have accurate raw symbol indices, updating that is moved into the
writer class.
Differential Revision: https://reviews.llvm.org/D57009
llvm-svn: 351947
This was reverted since it broke a couple buildbots. The reason
for the breakage is not yet known, but this time, the test has
got more diagnostics added, to hopefully allow figuring out
what goes wrong.
Differential Revision: https://reviews.llvm.org/D57007
llvm-svn: 351931
Summary:
This patch changes a few methods to return Error instead of manually calling error/reportError to abort. This will make it easier to extract into a library.
Note that error() takes just a string (this patch also adds an overload that takes an Error), while reportError() takes string + [error/code]. To help unify things, use FileError to associate a given filename with an error. Note that this takes some special care (for now), e.g. calling reportError(FileName, <something that could be FileError>) will duplicate the filename. The goal is to eventually remove reportError() and have every error associated with a file to be a FileError, and just one error handling block at the tool level.
This change was suggested in D56806. I took it a little further than suggested, but completely fixing llvm-objcopy will take a couple more patches. If this approach looks good, I'll commit this and apply similar patche(s) for the rest.
This change is NFC in terms of non-error related code, although the error message changes in one context.
Reviewers: alexshap, jhenderson, jakehehrlich, mstorsjo, espindola
Reviewed By: alexshap, jhenderson
Subscribers: llvm-commits, emaste, arichardson
Differential Revision: https://reviews.llvm.org/D56930
llvm-svn: 351896
This was requested in the review of D57006.
Also add missing quotes around symbol names in error messages.
Differential Revision: https://reviews.llvm.org/D57014
llvm-svn: 351799
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
Fix llvm-objcopy to add .note sections as SHT_NOTEs. GNU objcopy overrides section flags for special sections. For `.note` sections (with the exception of `.note.GNU-stack`), SHT_NOTE is used.
Many other sections are special cased by libbfd, but `.note` is the only special section I can seem to find being used with objcopy --add-section.
See `.note` in context of the full list of special sections here: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=bfd/elf.c;h=eb3e1828e9c651678b95a1dcbc3b124783d1d2be;hb=HEAD#l2675
Reviewers: jhenderson, alexshap, jakehehrlich, espindola
Reviewed By: jhenderson
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D56570
llvm-svn: 351204
These were copied as part of the original design from the ELF
backend, but aren't necessary at the moment.
Differential Revision: https://reviews.llvm.org/D56431
llvm-svn: 350996
Previously, this was broken - by setting PointerToSymbolTable to zero
but still actually writing the string table length, the object file
header was corrupted.
Differential Revision: https://reviews.llvm.org/D56584
llvm-svn: 350926
Summary:
The -O flag is currently being mostly ignored; it's only checked whether or not the output format is "binary". This adds support for a few formats (e.g. elf64-x86-64), so that when specified, the output can change between 32/64 bit and sizes/alignments are updated accordingly.
This fixes PR39135
Reviewers: jakehehrlich, jhenderson, alexshap, espindola
Reviewed By: jhenderson
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D53667
llvm-svn: 350541
Summary:
Fix EntrySize, Size, and Align before doing layout calculation.
As a side cleanup, this removes a dependence on sizeof(Elf_Sym) within BinaryReader, so we can untemplatize that.
This unblocks a cleaner implementation of handling the -O<format> flag. See D53667 for a previous attempt. Actual implementation of the -O<format> flag will come in an upcoming commit, this is largely a NFC (although not _totally_ one, because alignment on binary input was actually wrong before).
Reviewers: jakehehrlich, jhenderson, alexshap, espindola
Reviewed By: jhenderson
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D56211
llvm-svn: 350336
This fixes all cases of errors in asan+ubsan builds.
Also use std::copy instead of if+memcpy in the previously updated spot,
for consistency.
llvm-svn: 349826
This is an initial implementation of no-op passthrough copying of COFF
with objcopy.
Differential Revision: https://reviews.llvm.org/D54939
llvm-svn: 349605
Summary:
In both Elf{32,64}_Phdr, the field Elf{32,64}_World p_type is uint32_t.
Also reorder the fields to be similar to Elf64_Phdr (which is different
from Elf32_Phdr but quite similar).
Reviewers: rupprecht, jhenderson, jakehehrlich, alexshap, espindola
Reviewed By: rupprecht
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D55618
llvm-svn: 348985
Using an Error as an out parameter from an indirect operation like
iteration as described in the documentation (
http://llvm.org/docs/ProgrammersManual.html#building-fallible-iterators-and-iterator-ranges
) seems to be a little fussy - so here's /one/ possible solution, though
I'm not sure it's the right one.
Alternatively such APIs may be better off being switched to a standard
algorithm style, where they take a lambda to do the iteration work that
is then called back into (eg: "Error e = obj.for_each_note([](const
Note& N) { ... });"). This would be safer than having an unwritten
assumption that the user of such an iteration cannot return early from
the inside of the function - and must always exit through the gift
shop... I mean error checking. (even though it's guaranteed that if
you're mid-way through processing an iteration, it's not in an error
state).
Alternatively we'd need some other (the super untrustworthy/thing we've
generally tried to avoid) error handling primitive that actually clears
the error state entirely so it's safe to ignore.
Fleshed this solution out a bit further during review - it now relies on
op==/op!= comparison as the equivalent to "if (Err)" testing the Error.
So just like an Error must be checked (even if it's in a success state),
the Error hiding in the iterator must be checked after each increment
(including by comparison with another iterator - perhaps this could be
constrained to only checking if the iterator is compared to the end
iterator? Not sure it's too important).
So now even just creating the iterator and not incrementing it at all
should still assert because the Error has not been checked.
Reviewers: lhames, jakehehrlich
Differential Revision: https://reviews.llvm.org/D55235
llvm-svn: 348811
I just hard core goofed when I wrote this and created a different name
for no good reason. I'm failry aware of most "fresh" users of llvm-objcopy
(that is, users which are not using it as a drop in replacement for GNU
objcopy) and can say that only "-j" is being used by such people so this
patch should strictly increase compatibility and not remove it.
Differential Revision: https://reviews.llvm.org/D52180
llvm-svn: 348446
This flag does not exist in GNU objcopy but has a major use case.
Debugging tools support the .build-id directory structure to find
debug binaries. There is no easy way to build this structure up
however. One way to do it is by using llvm-readelf and some crazy
shell magic. This implements the feature directly. It is most often
the case that you'll want to strip a file and send the original to
the .build-id directory but if you just want to send a file to the
.build-id directory you can copy to /dev/null instead.
Differential Revision: https://reviews.llvm.org/D54384
llvm-svn: 348174
Summary: The original intention of !Config.xx.empty() was probably to emphasize the thing that is currently considered, but I feel the simplified form is actually easier to understand and it is also consistent with the call sites in other llvm components.
Reviewers: alexshap, rupprecht, jakehehrlich, jhenderson, espindola
Reviewed By: alexshap, rupprecht
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D55040
llvm-svn: 347891
This allows libtool to detect the presence of llvm-strip and use
it with the options --strip-debug and --strip-unneeded.
Also hook up the -V alias for objcopy.
Differential Revision: https://reviews.llvm.org/D54936
llvm-svn: 347731
Summary:
llvm-objcopy/strip support `--keep` (for sections) and `--keep-symbols` (for symbols). For consistency and clarity, rename `--keep` to `--keep-section`.
In fact, for GNU compatability, -K is --keep-symbol, so it's weird that the alias `-K` is not the same as the short-ish `--keep`.
Reviewers: jakehehrlich, jhenderson, alexshap, MaskRay, espindola
Reviewed By: jakehehrlich, MaskRay
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D54477
llvm-svn: 346782
In a lot of places an empty string was passed as the ErrorBanner to
logAllUnhandledErrors. This patch makes that argument optional to
simplify the call sites.
llvm-svn: 346604
Summary: If argv[0] is version suffixed, e.g. llvm-strip-7, this will still work.
Reviewers: rupprecht, jhenderson, alexshap, jakehehrlich
Reviewed By: rupprecht
Subscribers: alexshap, jakehehrlich, llvm-commits
Differential Revision: https://reviews.llvm.org/D54193
llvm-svn: 346292
Summary: ar and objcopy/strip all support configuring whether archives are written deterministically (timestamps/UIDs/GIDs/etc zero'd). This has been ported to llvm-ar (the U/D modifiers) but not yet to llvm-objcopy/strip.
Reviewers: jakehehrlich, jhenderson, alexshap
Reviewed By: jhenderson
Subscribers: ruiu, mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D53913
llvm-svn: 345859
Summary:
--localize-symbol and --localize-hidden will currently localize common symbols. GNU objcopy will not localize these symbols even when explicitly requested, which seems reasonable; common symbols should always be global so they can be merged during linking.
See PR39461
Reviewers: jakehehrlich, jhenderson, alexshap, MaskRay, espindola
Reviewed By: jakehehrlich, jhenderson, alexshap, MaskRay
Subscribers: emaste, arichardson, alexshap, MaskRay, llvm-commits
Differential Revision: https://reviews.llvm.org/D53782
llvm-svn: 345856
Summary: --keep-global-symbol and --globalize-symbol don't make sense for undefined symbols, so it should be ignored for those symbols. This matches GNU objcopy behavior.
Reviewers: jhenderson, alexshap, jakehehrlich, espindola
Reviewed By: jhenderson, jakehehrlich
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D53733
llvm-svn: 345614
In this diff the elf-specific code is moved into the subfolder ELF
(and factored out from llvm-objcopy.cpp).
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D53790
llvm-svn: 345544
In this diff we introduce dispatch mechanism based on
the type of the input (archive, object file, raw binary)
and the format (coff, elf, macho).
We also move the ELF-specific code into the namespace llvm::objcopy::elf.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D53311
llvm-svn: 345217
Summary:
GNU strip supports both `-s` and `-S` as aliases for `--strip-all` and `--strip-debug`, respectfully.
As part of this, it turns out that strip/objcopy were accepting case insensitive command line args. I'm not sure if there was an explicit reason for this. The only others uses of this are llvm-cvtres/llvm-mt/llvm-lib, which are all tools specific for windows support. Forcing case sensitivity allows both aliases to exist, but seems like a good idea anyway.
And as a surprise test case adjustment, the llvm-strip unit test was running with `-keep=unavailable_symbol`, despite `keep` not be a valid flag for strip. This is because there is a flag `-K` which, when case insensitivity is permitted, allows it to be interpreted as `-K` = `eep=unavailable_symbol` (e.g. to allow `-Kfoo` == `--keep-symbol=foo`).
Reviewers: jakehehrlich, jhenderson, alexshap
Reviewed By: jakehehrlich
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D53163
llvm-svn: 345068
In this diff we move out the hierarchy of buffers from Object.h/Object.cpp
into separate files since it is not ELF-specific and will be reused later.
After this change Object.h/Object.cpp are almost exclusively ELF-specific.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D53298
llvm-svn: 344585
Summary:
This change adds support for the GNU --target flag, which sets both --input-target and --output-target.
GNU objcopy doesn't do any checking for whether both --target and --{input,output}-target are used, and so it allows both, e.g. "--target A --output-target B" is equivalent to "--input-target A --output-target B" since the later command line flag would override earlier ones. This may be error prone, so I chose to implement it as an error if both are used. I'm not sure if anyone is actually using both.
Reviewers: jakehehrlich, jhenderson, alexshap
Reviewed By: jakehehrlich, alexshap
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D53029
llvm-svn: 344321
In this diff we move out CopyConfig from llvm-oobjcopy.cpp into a separate header CopyConfig.h
to enable us (in the future) reuse this class in the other implementations of objcopy (for coff, mach-o).
Additionally this enables us to unload the complexity from llvm-objcopy.cpp a little bit.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D53006
llvm-svn: 344307
Summary:
Before, "[options] <inputs>" is unconditionally appended to the `Name` parameter. It is more flexible to change its semantic to `Usage` and let user customize the usage line.
% llvm-objcopy
...
USAGE: llvm-objcopy <input> [ <output> ] [options] <inputs>
With this patch:
% llvm-objcopy
...
USAGE: llvm-objcopy input [output]
Reviewers: rupprecht, alexshap, jhenderson
Reviewed By: rupprecht
Subscribers: jakehehrlich, mehdi_amini, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D51009
llvm-svn: 344097
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
llvm-svn: 343451
Summary:
Implement --version for objcopy and strip.
I think there are LLVM utilities that automatically handle this, but that doesn't seem to work with custom parsing since this binary handles both objcopy and strip, so it uses custom parsing.
This fixes PR38298
Reviewers: jhenderson, alexshap, jakehehrlich
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D52328
llvm-svn: 342702
This diff adds -S as an alias for --strip-all-gnu
(for compatibility with binutils' objcopy).
Patch by Dmitry Golovin!
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D52163
llvm-svn: 342364
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
llvm-svn: 342065
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
llvm-svn: 341635
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
llvm-svn: 341607
Summary:
Allow strip to be called on multiple input files, which is interpreted as stripping N files in place. Using multiple input files is incompatible with -o.
To allow this, create a `DriverConfig` struct which just wraps a list of `CopyConfigs`. objcopy will only ever have a single `CopyConfig`, but strip will have N (where N >= 1) CopyConfigs.
Reviewers: alexshap, jakehehrlich
Reviewed By: alexshap, jakehehrlich
Subscribers: MaskRay, jakehehrlich, llvm-commits
Differential Revision: https://reviews.llvm.org/D51660
llvm-svn: 341464
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
llvm-svn: 341419
Also reverts follow-up commits r341343 and r341344.
The primary commit continues to break some build bots even after the
fixes in r341343 for UBSan issues:
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full/builds/5823
It is also failing for me locally (linux, x86-64).
llvm-svn: 341360
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
llvm-svn: 341342
The restoreDateOnFile() method used to preserve dates uses sys::fs::openFileForWrite(). That method defaults to opening files with CD_CreateAlways, which truncates the output file if it exists. Use CD_OpenExisting instead to open it and *not* truncate it, which also has the side benefit of erroring if the file does not exist (it should always exist, because we just wrote it out).
Also, fix the test case to make sure the output is a valid output file, and not empty. The extra test assertions are enough to catch this regression.
llvm-svn: 340996
Summary: Before, llvm-strip accepted a second argument but it would just be ignored.
Reviewers: alexshap, jhenderson, paulsemel
Reviewed By: alexshap
Subscribers: jakehehrlich, rupprecht, llvm-commits
Differential Revision: https://reviews.llvm.org/D51004
llvm-svn: 340229
Summary:
Port GNU Objcopy -G/--keep-global-symbol(s).
This is slightly different than the already-implemented --globalize-symbol, which marks a symbol as global when copying. When --keep-global-symbol (alias -G) is used, *only* those symbols marked will stay global, and all other globals are demoted to local. (Also note that it doesn't *promote* a symbol to global). Additionally, there is a pluralized version of the flag --keep-global-symbols, which effectively applies --keep-global-symbol for every non-comment in a file.
Reviewers: jakehehrlich, jhenderson, alexshap
Reviewed By: jhenderson
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50589
llvm-svn: 340105
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
llvm-svn: 340070
Summary:
Add support for --rename-section flags from gnu objcopy.
Not all flags appear to have an effect for ELF objects, but allowing them would allow easier drop-in replacement. Other unrecognized flags are rejected.
This was only tested by comparing flags printed by "readelf -e <.o>" against the output of gnu vs llvm objcopy, it hasn't been tested to be valid beyond that.
Reviewers: jakehehrlich, alexshap
Subscribers: llvm-commits, paulsemel, alexshap
Differential Revision: https://reviews.llvm.org/D49870
llvm-svn: 338582
Summary:
See binutils-gdb/bfd/elf.c, GNU objcopy also strips .stab* (STABS)
.line* (DWARF 1) .gnu.linkonce.wi.* (linkonce section for .debug_info) but
I'm not sure we need to be compatible with it.
Reviewers: dblaikie, alexshap, jakehehrlich, jhenderson
Reviewed By: alexshap, jakehehrlich
Subscribers: aprantl, JDevlieghere, jakehehrlich, llvm-commits
Differential Revision: https://reviews.llvm.org/D50100
llvm-svn: 338443
Summary:
These two cases will trigger a dereference on a nullptr, since the
SymbolTable can be nonexistent for a given library, in addition to just
being empty.
Reviewers: alexshap
Reviewed By: alexshap
Subscribers: meikeb, kongyi, chh, jakehehrlich, llvm-commits, pirama
Differential Revision: https://reviews.llvm.org/D49534
llvm-svn: 338062
Summary:
Add basic support for --rename-section=old=new to llvm-objcopy.
A full replacement for GNU objcopy requires also modifying flags (i.e. --rename-section=old=new,flag1,flag2); I'd like to keep that in a separate change to keep this simple.
Reviewers: jakehehrlich, alexshap
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49576
llvm-svn: 337604
Nest any classes not used outside of a file into anon. Nest any classes used
across files in llvm-objcopy into namespace llvm::objcopy.
Differential Revision: https://reviews.llvm.org/D49449
llvm-svn: 337337
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.
llvm-svn: 337220
This patch is an update of an older patch that never landed
(see here: https://reviews.llvm.org/D42516)
Recently various users have run into this issue and it just 100%
has to be solved at this point. The main difference in this patch
is that I use gunzip instead of unzip which should hopefully allow
tests to pass. Please review this as if it is a new patch however.
I found some issues along the way and made some minor modifications.
The binary used in this patch for testing (a zip file to make it small)
can be found here:
https://drive.google.com/file/d/1UjsnTO9edLttZibbr-2T1bJl92KEQFAO/view?usp=sharing
Differential Revision: https://reviews.llvm.org/D49206
llvm-svn: 337204
Summary:
This option appears to have been dropped as part of the refactoring in
r331663. Unfortunately, if we want to use llvm-strip as a drop-in
replacement for strip, this option should still be available.
Reviewers: alexshap
Reviewed By: alexshap
Subscribers: meikeb, kongyi, chh, jakehehrlich, llvm-commits, pirama
Differential Revision: https://reviews.llvm.org/D49226
llvm-svn: 336921
This diff adds support for handling static libraries
to llvm-objcopy and llvm-strip.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D48413
llvm-svn: 336455
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
llvm-svn: 334217
This fixes the bug where strip-all option was
leading to a malformed outputted ELF file.
Differential Revision: https://reviews.llvm.org/D47414
llvm-svn: 333772
This diff implements the option -o
for specifying a file to write the output to.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D47505
llvm-svn: 333693
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
llvm-svn: 333581
This is a small follow-up to the revisions r333117 and r331663.
1. Avoid the name conflicts of the generated variables for prefixes.
2. Apply clang-format -i -style=llvm to llvm-objcopy.cpp once again.
3. Add a test for the flag with double dash.
Test plan: make check-all
llvm-svn: 333120
If one runs llvm-objcopy --strip-all --keep-symbol foo
and the symbol table indeed contains the symbol "foo"
then it should not be removed.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D47052
llvm-svn: 333008
This option just keeps being a problem and really needs to be implemented
in some fashion. Implementing it properly requires some kind of
"replaceSectionReference" method because all the existing links need to be
maintained. The desired behavior is just for allocated sections to become
NOBITS but actually implementing that is rather tricky due to the current
design of llvm-objcopy. However converting allocated sections to NOBITS is
just an optimization and not something debuggers need. Debuggers can debug
a stripped executable and take an unstripped executable for that stripped
executable as input. Additionally allocated sections account for a very
small part of debug binaries so this optimization is quite small. I propose
that for the time being we implement this as a NOP so that people can use
llvm-objcopy where they need to, just in a sub-optimal way.
This option has already blocked a lot of people and its currently blocking me.
llvm-svn: 332396
This option permits to explicitly keep the specified
symbol so that it doesn't get removed.
Differential Revision: https://reviews.llvm.org/D46819
llvm-svn: 332356
This diff adds support for -remove-section to llvm-strip.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D46567
llvm-svn: 332081
Set the exit code to 1 if no arguments are specified.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D46547
llvm-svn: 331776
llvm-strip is supposed to be a drop-in replacement for binutils strip.
To start the ball rolling this diff adds the initial bits for llvm-strip,
more features will be added incrementally over time.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D46407
llvm-svn: 331663
This diff implements --redefine-sym option
for changing the name of a symbol.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D46029
llvm-svn: 330973
Add explicit dependency on ObjcopyTableGen
and rerun the tests on Windows.
I will double-check the build bots
and revert this commit if necessary.
llvm-svn: 330685
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
llvm-svn: 330478
We have a few functions that virtually all command wants to run on
process startup/shutdown. This patch adds InitLLVM class to do that
all at once, so that we don't need to copy-n-paste boilerplate code
to each llvm command's main() function.
Differential Revision: https://reviews.llvm.org/D45602
llvm-svn: 330046
Swithces from using the command line library to using TableGen. This will allow
llvm-strip to exist and allow refinements of the command line syntax.
Differential Revision: https://reviews.llvm.org/D44236
llvm-svn: 329863
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
Somehow a few massive errors slipped though the cracks of testing.
1. The code in Segment::finalize was left over from the old layout
algorithm. In certain situations this would cause very strange issues
with segment layout. For instance in the shift-segments.test case it
would cause the second segment to have the same offset as the first.
2. In debugging this I discovered another issue. Namely section alignment
was not being computed based on Section->Align but instead
Section->Offset which is bizarre and makes no sense. I have no clue how
it worked in the first place. This issue is also fixed
3. Fixing #2 exposed a bug where things were not being written past the end
of the file that technically should have been. This was because in
certain cases (like overlapping-segments) the end of the file wouldn't
always be bumped if the offset could be chosen relative to an existing
segment that already had it's offset chosen. For fully nested segments
this is fine but for overlapping segments this leaves the end of the
file short. So I changed how the offset is bumped when looping though
segments.
Differential Revision: https://reviews.llvm.org/D38436
llvm-svn: 314918
This change adds support for dynamic relocations (allocated
SHT_REL/SHT_RELA sections with a dynamic symbol table as their link).
I had to reland this because of a I wasn't initilizing some pointers.
llvm-svn: 314263
This change refactors some of the code to allow for some code
deduplication in later diffs as well as just to make adding a new
section type more self contained to the class itself. The idea for this
was first mentioned by James in D 37915 and will be used in that change
as recommended.
This change follows changes for dynamic sections but precedes support
for dynamic relocations.
Differential Revision: https://reviews.llvm.org/D38008
llvm-svn: 314148
I overzealously landed this before I was sure that another change
wouldn't break the build that this change depends on.
This change adds support for sections involved in dynamic loading such
as SHT_DYNAMIC, SHT_DYNSYM, and allocated string tables.
The two added binaries used for tests can be downloaded here and here
Differential Revision: https://reviews.llvm.org/D36560
llvm-svn: 313767
I didn't initialize a pointer to be nullptr that I needed to.
This change adds support for nested and even overlapping segments. This means
that PT_PHDR, PT_GNU_RELRO, PT_TLS, and PT_DYNAMIC can be supported properly.
Differential Revision: https://reviews.llvm.org/D36558
llvm-svn: 313682
This change adds support for nested and even overlapping segments. This means
that PT_PHDR, PT_GNU_RELRO, PT_TLS, and PT_DYNAMIC can be supported properly.
Differential Revision: https://reviews.llvm.org/D36558
llvm-svn: 313656
As discussed on llvm-commits it was decided it would be best to check
e_machine before declaring that a reserved section index is valid. The
only special e_machine value that matters here is EM_HEXAGON. This
change adds a special check for EM_HEXAGON.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D37767
llvm-svn: 313114
As is indexes above SHN_LORESERVE will not be handled correctly because
they'll be treated as indexes of sections rather than special values
that should just be copied. This change adds support to copy them
though.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D37393
llvm-svn: 312756
This change adds support for SHT_REL and SHT_RELA sections in
llvm-objcopy.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D36554
llvm-svn: 312680
This change adds support for SHT_REL and SHT_RELA sections in
llvm-objcopy.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D36554
llvm-svn: 312643
The current file layout algorithm in llvm-objcopy is simple but
difficult to reason about. It also makes it very complicated to support
nested segments and to support segments that have offsets that come
before a point after the program headers. To support these cases and
simplify one of the most critical parts llvm-objcopy I rewrote the
layout algorithm. Laying out segments first solves most of the issues
encountered by the previous algorithm.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D36494
llvm-svn: 311825
Sometimes LLD will produce a PT_LOAD segment that only covers the
headers (and covers no sections). GNU objcopy does not output the
segment contents for these sections. In particular this is an issue in
building magenta because the final link step for the kernel would
produce just such a PT_LOAD segment. This change is to support this case
and to match what GNU objcopy does in this case.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D36196
llvm-svn: 310149
This change adds the "-O binary" flag which directs llvm-objcopy to
output the object file to the same format as GNU objcopy does when given
the flag "-O binary". This was done by splitting the Object class into
two subclasses ObjectELF and ObjectBianry which each output a different
format but relay on the same code to read in the Object in Object.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D34480
llvm-svn: 310127
This change adds the "-O binary" flag which directs llvm-objcopy to
output the object file to the same format as GNU objcopy does when given
the flag "-O binary". This was done by splitting the Object class into
two subclasses ObjectELF and ObjectBianry which each output a different
format but relay on the same code to read in the Object in Object.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D34480
llvm-svn: 310018
This change adds the "-O binary" flag which directs llvm-objcopy to
output the object file to the same format as GNU objcopy does when given
the flag "-O binary". This was done by splitting the Object class into
two subclasses ObjectELF and ObjectBianry which each output a different
format but relay on the same code to read in the Object in Object.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D34480
llvm-svn: 309768
This change adds the "-O binary" flag which directs llvm-objcopy to
output the object file to the same format as GNU objcopy does when given
the flag "-O binary". This was done by splitting the Object class into
two subclasses ObjectELF and ObjectBianry which each output a different
format but relay on the same code to read in the Object in Object.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D34480
llvm-svn: 309658
As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
llvm-svn: 309643
As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
llvm-svn: 309249
As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
llvm-svn: 309032
As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
llvm-svn: 308821
As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
llvm-svn: 308803
As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
llvm-svn: 308559
James Henderson