Commit Graph

237 Commits

Author SHA1 Message Date
Jordan Rupprecht 18886db211 [llvm-objcopy][NFC] More error propagation (executeObjcopyOnArchive)
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
2019-02-01 17:08:07 +00:00
Eugene Leviant 05a3f9978e [llvm-strip] Implement --keep-file-symbols
Differential revision: https://reviews.llvm.org/D57582

llvm-svn: 352878
2019-02-01 15:25:15 +00:00
Jordan Rupprecht 971d4762b6 [llvm-objcopy][NFC] Propagate errors in removeSymbols/removeSectionReferences
Reviewers: jhenderson, alexshap, jakehehrlich, espindola

Reviewed By: jhenderson

Subscribers: emaste, arichardson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57543

llvm-svn: 352877
2019-02-01 15:20:36 +00:00
Jordan Rupprecht bd7735f797 [llvm-objcopy] Skip --localize-symbol for undefined symbols
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
2019-01-31 16:45:16 +00:00
Eugene Leviant 2267c58aea [llvm-strip] Add --strip-symbol
Differential revision: https://reviews.llvm.org/D57440

llvm-svn: 352746
2019-01-31 12:16:20 +00:00
Jordan Rupprecht fc832e9a24 [llvm-objcopy][NFC] More error propagation (linkToBuildIdDir)
llvm-svn: 352640
2019-01-30 18:13:30 +00:00
Jordan Rupprecht d0f7bcfbe1 [llvm-objcopy] Support -X|--discard-locals.
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
2019-01-30 14:58:13 +00:00
Jordan Rupprecht 307deab40a [llvm-objcopy][NFC] More error propagation
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
2019-01-30 14:36:53 +00:00
Jordan Rupprecht c892741e74 [llvm-objcopy] Implement --set-section-flags.
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
2019-01-29 15:05:38 +00:00
Jordan Rupprecht b2702d6a45 [llvm-objcopy] Fix crash when writing empty binary output
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
2019-01-28 15:02:40 +00:00
Douglas Yung 914e838e63 [llvm-objcopy] Add support for -g as an alias for --strip-debug
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
2019-01-25 09:57:20 +00:00
Martin Storsjo 0d19a399a3 [llvm-objcopy] [COFF] Error out on use of unhandled options
Prefer erroring out than silently not doing what was requested.

Differential Revision: https://reviews.llvm.org/D57045

llvm-svn: 351948
2019-01-23 11:54:55 +00:00
Martin Storsjo 1be91958b3 [llvm-objcopy] [COFF] Fix handling of aux symbols for big objects
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
2019-01-23 11:54:51 +00:00
Martin Storsjo 8f52c0376b [llvm-objcopy] [COFF] Clear the unwritten tail of coff_section::Header::Name
This should fix the add-gnu-debuglink test on all buildbots.

llvm-svn: 351934
2019-01-23 09:12:53 +00:00
Martin Storsjo 12b6b80208 Reapply: [llvm-objcopy] [COFF] Implement --add-gnu-debuglink
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
2019-01-23 08:25:28 +00:00
Jordan Rupprecht 881cae7a45 [llvm-objcopy] Return Error from Buffer::allocate(), [ELF]Writer::finalize(), and [ELF]Writer::commit()
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
2019-01-22 23:49:16 +00:00
Martin Storsjo f614ace3e4 Revert "[llvm-objcopy] [COFF] Implement --add-gnu-debuglink"
This reverts commit r351801, as it caused errors on (so far)
ppc64be and aarch64 buildbots - the reason is yet unknown.

llvm-svn: 351811
2019-01-22 12:35:34 +00:00
Martin Storsjo 1bf1964a15 [llvm-objcopy] [COFF] Implement --add-gnu-debuglink
Differential Revision: https://reviews.llvm.org/D57007

llvm-svn: 351801
2019-01-22 10:58:18 +00:00
Martin Storsjo 9ec18a3718 [llvm-objcopy] [COFF] Update symbol indices in weak externals
Differential Revision: https://reviews.llvm.org/D57006

llvm-svn: 351800
2019-01-22 10:58:09 +00:00
Martin Storsjo 8010c6beaf [llvm-objcopy] Consistently use createStringError instead of make_error<StringError>
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
2019-01-22 10:57:59 +00:00
Martin Storsjo e8305175b0 [llvm-objcopy] [COFF] Implement --only-section
Differential Revision: https://reviews.llvm.org/D56873

llvm-svn: 351663
2019-01-19 19:42:54 +00:00
Martin Storsjo 1868d88b2e [llvm-objcopy] [COFF] Implement --only-keep-debug
Differential Revision: https://reviews.llvm.org/D56840

llvm-svn: 351662
2019-01-19 19:42:48 +00:00
Martin Storsjo 78a0b418b4 [llvm-objcopy] [COFF] Implement --strip-debug
Also remove sections similarly for --strip-all, --discard-all,
--strip-unneeded.

Differential Revision: https://reviews.llvm.org/D56839

llvm-svn: 351661
2019-01-19 19:42:41 +00:00
Martin Storsjo f9e1434ef4 [llvm-objcopy] [COFF] Add support for removing sections
Differential Revision: https://reviews.llvm.org/D56683

llvm-svn: 351660
2019-01-19 19:42:35 +00:00
Martin Storsjo 1004242a3e [llvm-objcopy] [COFF] Remove a superfluous namespace qualification. NFC.
llvm-svn: 351658
2019-01-19 19:42:23 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
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
2019-01-19 08:50:56 +00:00
Jordan Rupprecht 17dd4a2c5e [llvm-objcopy] Use SHT_NOTE for added note sections.
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
2019-01-15 16:57:23 +00:00
Martin Storsjo f51f5ea6d5 [llvm-objcopy] [COFF] Implement --strip-all[-gnu] for symbols
Differential Revision: https://reviews.llvm.org/D56481

llvm-svn: 351174
2019-01-15 09:34:55 +00:00
Martin Storsjo 4b0694b712 [llvm-objcopy] [COFF] Remove unreferenced undefined externals with --strip-unneeded.
Differential Revision: https://reviews.llvm.org/D56660

llvm-svn: 351099
2019-01-14 18:56:47 +00:00
Martin Storsjo 6a4d2d6561 [llvm-objcopy] [COFF] Remove pointless Reader/Writer base classes. NFC.
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
2019-01-12 08:30:09 +00:00
Martin Storsjo fb909207c6 [llvm-objcopy] [COFF] Implmement --strip-unneeded and -x/--discard-all for symbols
Differential Revision: https://reviews.llvm.org/D56480

llvm-svn: 350927
2019-01-11 14:13:04 +00:00
Martin Storsjo d1cc64fe12 [llvm-objcopy] [COFF] Fix writing object files without symbols/string table
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
2019-01-11 13:47:37 +00:00
Martin Storsjo 4c1c4fc869 [llvm-objcopy] [COFF] Fix warnings abuilt missing field initialization. NFC.
llvm-svn: 350898
2019-01-10 21:59:41 +00:00
Martin Storsjo 10b7296484 [llvm-objcopy] [COFF] Add support for removing symbols
Differential Revision: https://reviews.llvm.org/D55881

llvm-svn: 350893
2019-01-10 21:28:24 +00:00
Jordan Rupprecht 70038e01c8 [llvm-objcopy] Handle -O <format> flag.
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
2019-01-07 16:59:12 +00:00
Jordan Rupprecht 415dc5dd0c [llvm-objcopy] Fix buildbots on older compilers
llvm-svn: 350343
2019-01-03 19:09:00 +00:00
Jordan Rupprecht 78213c7e2c Fix typos in comments
llvm-svn: 350337
2019-01-03 17:51:32 +00:00
Jordan Rupprecht 1f82176f7d [llvm-objcopy][ELF] Implement a mutable section visitor that updates size-related fields (Size, EntrySize, Align) before layout.
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
2019-01-03 17:45:30 +00:00
Martin Storsjo 0a5d5b1377 [llvm-objcopy] [COFF] Use Error/Expected returns instead of calling reportError. NFC.
Differential Revision: https://reviews.llvm.org/D55922

llvm-svn: 350168
2018-12-30 20:35:43 +00:00
Martin Storsjo 14cfa9ae2e [llvm-objcopy] [COFF] Avoid memcpy() with null parameters in more places. NFC.
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
2018-12-20 21:35:59 +00:00
Martin Storsjo 02e96dd039 [llvm-objcopy] [COFF] Don't call memcpy() with a null argument. NFC.
It is invalid to call memcpy with a null pointer, even if the size
is zero.

This should fix the sanitizer buildbot.

llvm-svn: 349808
2018-12-20 19:48:39 +00:00
George Rimar 3ac20a927c [llvm-objcopy] Use ELFOSABI_NONE instead of 0. NFC.
This was requested during the review of D55886.
(sorry, forgot to address this)

llvm-svn: 349741
2018-12-20 10:59:52 +00:00
George Rimar 4ded77334e [llvm-objcopy] - Do not drop the OS/ABI and ABIVersion fields of ELF header
This is https://bugs.llvm.org/show_bug.cgi?id=40005,

Patch teaches llvm-objcopy to preserve OS/ABI and ABIVersion fields of ELF header.
(Currently, it drops them to zero).

Differential revision: https://reviews.llvm.org/D55886

llvm-svn: 349738
2018-12-20 10:51:42 +00:00
Jordan Rupprecht 16a0de2e55 [binutils] NFC: fix clang-tidy warning: use empty() instead of size() == 0
llvm-svn: 349710
2018-12-20 00:57:06 +00:00
Martin Storsjo 2a632b6472 [llvm-objcopy] [COFF] Fix the Object forward declaration
This fixes build warnings with clang, and linker errors with MSVC.

llvm-svn: 349606
2018-12-19 07:45:06 +00:00
Martin Storsjo e84a0b5a9e [llvm-objcopy] Initial COFF support
This is an initial implementation of no-op passthrough copying of COFF
with objcopy.

Differential Revision: https://reviews.llvm.org/D54939

llvm-svn: 349605
2018-12-19 07:24:38 +00:00
Fangrui Song 967ce406d5 [llvm-objcopy] Change Segment::Type from uint64_t to uint32_t
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
2018-12-12 22:46:37 +00:00
David Blaikie ba005aa43c llvm-objcopy: Improve/simplify llvm::Error handling during notes iteration
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
2018-12-11 00:09:06 +00:00
Jake Ehrlich 85985ed363 [llvm-objcopy] Change --only-keep to --only-section
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
2018-12-06 02:03:53 +00:00
Jake Ehrlich 8ad7779071 [llvm-objcopy] Add --build-id-link-dir flag
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
2018-12-03 19:49:23 +00:00