52 Commits

Author SHA1 Message Date
Rumeet Dhindsa
4ee933c76b Revert [llvm-objcopy][NFC] Refactor output target parsing
This reverts r364254 (git commit 545f001d1b9a7b58a68d75e70bfc36c841de8999)

This change causes some llvm-obcopy tests to fail with valgrind.

Following is the output for basic-keep.test
Command Output (stderr):
--

==107406== Conditional jump or move depends on uninitialised value(s)
==107406==    at 0x1A30DD: executeObjcopy(llvm::objcopy::CopyConfig const&) (llvm-objcopy.cpp:235)
==107406==    by 0x1A3935: main (llvm-objcopy.cpp:294)

llvm-svn: 364379
2019-06-26 03:00:57 +00:00
Seiya Nuta
545f001d1b [llvm-objcopy][NFC] Refactor output target parsing
Summary:
Use an enum instead of string to hold the output file format in Config.InputFormat and Config.OutputFormat. It's essential to support other output file formats other than ELF.

Reviewers: espindola, alexshap, rupprecht, jhenderson

Reviewed By: rupprecht, jhenderson

Subscribers: jyknight, compnerd, emaste, arichardson, fedor.sergeev, jakehehrlich, MaskRay, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63239

llvm-svn: 364254
2019-06-25 00:02:04 +00:00
Eugene Leviant
86b7f865ac [llvm-objcopy] Implement IHEX reader
This is the final part of IHEX format support in llvm-objcopy
Differential revision: https://reviews.llvm.org/D62583

llvm-svn: 363243
2019-06-13 09:56:14 +00:00
Simon Pilgrim
1a6ce24ee1 Fix -Wunused-lambda-capture warning. NFCI.
llvm-svn: 362822
2019-06-07 18:20:09 +00:00
Peter Collingbourne
8d58a98c59 llvm-objcopy: Implement --extract-partition and --extract-main-partition.
This implements the functionality described in
https://lld.llvm.org/Partitions.html. It works as follows:

- Reads the section headers using the ELF header at file offset 0;
- If extracting a loadable partition:
  - Finds the section containing the required partition ELF header by looking it up in the section table;
  - Reads the ELF and program headers from the section.
- If extracting the main partition:
  - Reads the ELF and program headers from file offset 0.
- Filters the section table according to which sections are in the program headers that it read:
  - If ParentSegment != nullptr or section is not SHF_ALLOC, then it goes in.
  - Sections containing partition ELF headers or program headers are excluded as there are no headers for these in ordinary ELF files.

Differential Revision: https://reviews.llvm.org/D62364

llvm-svn: 362818
2019-06-07 17:57:48 +00:00
Eugene Leviant
a6fb183c98 [llvm-objcopy] Implement IHEX writer
Differential revision: https://reviews.llvm.org/D60270

llvm-svn: 361949
2019-05-29 11:37:16 +00:00
George Rimar
c1cc8d0eca [llvm-objcopy] - Strip undefined symbols if they are no longer referenced following --only-section
This is https://bugs.llvm.org/show_bug.cgi?id=40004.

In this patch I teach llvm-objcopy to remove undefined symbols if
them are not used anymore after applying -j/--only-section option.

Differential revision: https://reviews.llvm.org/D62317

llvm-svn: 361642
2019-05-24 15:04:50 +00:00
Seiya Nuta
ada9d2d884 [llvm-objcopy] Add file names to error messages
Summary:
This patch adds the file names to llvm-objcopy error messages. It makes easy to identify which file causes an error.

Bugzilla: https://bugs.llvm.org/show_bug.cgi?id=41798

Reviewers: espindola, alexshap, rupprecht, jhenderson, jakehehrlich

Reviewed By: rupprecht, jhenderson, jakehehrlich

Subscribers: emaste, arichardson, jakehehrlich, MaskRay, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61993

llvm-svn: 361450
2019-05-23 00:42:46 +00:00
James Henderson
5316a0d200 [llvm-objcopy] Tidy up error messages
This patch brings various error messages into line with each other, by
removing trailing full stops, and making the first letter lower-case.
This addresses https://bugs.llvm.org/show_bug.cgi?id=40859.

Reviewed by: jhenderson, rupprecht, jakehehrlich

Differential Revision: https://reviews.llvm.org/D62072

Patch by Alex Brachet

llvm-svn: 361384
2019-05-22 13:23:26 +00:00
Eugene Leviant
ec767b0b4a [llvm-objcopy] Strip file symbols with --strip-unneeded
Differential revision: https://reviews.llvm.org/D61641

llvm-svn: 361231
2019-05-21 09:09:33 +00:00
James Henderson
9df3883618 [llvm-objcopy] Cache gnu_debuglink's target CRC
.gnu_debuglink section contains information regarding file with
debugging symbols, identified by its CRC32. This target file is not
intended to ever change or it would invalidate the stored checksum, yet
the checksum is calculated over and over again for each of the objects
inside the archive, usually hundreds of times.

This patch precomputes the CRC32 of the target once and then reuses the
value where required, saving lots of redundant I/O.

The error message reported should stay the same, although now it might
be reported earlier.

Reviewed by: jhenderson, jakehehrlich, MaskRay

Differential Revision: https://reviews.llvm.org/D61343

Patch by Michal Janiszewski

llvm-svn: 360661
2019-05-14 10:59:04 +00:00
James Henderson
fa11fb33ad [llvm-objcopy] Add --prefix-alloc-sections
This patch adds support for --prefix-alloc-sections, which adds a prefix
to every allocated section names.

It adds a prefix after renaming section names by --rename-section as GNU
objcopy does.

Fixes PR41266: https://bugs.llvm.org/show_bug.cgi?id=41266

Differential Revision: https://reviews.llvm.org/D60042

Patch by Seiya Nuta.

llvm-svn: 360233
2019-05-08 09:49:35 +00:00
Fangrui Song
aa1f2c50a8 [llvm-objcopy] Simplify SHT_NOBITS -> SHT_PROGBITS promotion
GNU objcopy uses bfd_elf_get_default_section_type to decide the candidate section type,
which roughly translates to our [a] (I assume SEC_COMMON implies SHF_ALLOC):

  (!(Sec.Flags & ELF::SHF_ALLOC) || Flags & (SectionFlag::SecContents | SectionFlag::SecLoad)))

Then, it updates the section type in bfd/elf.c:elf_fake_sections if:

  if (this_hdr->sh_type == SHT_NULL)
    this_hdr->sh_type = sh_type; // common case
  else if (this_hdr->sh_type == SHT_NOBITS
           && sh_type == SHT_PROGBITS
           && (asect->flags & SEC_ALLOC) != 0)  // uncommon case
    ...
    this_hdr->sh_type = sh_type;

If the following condition is met the uncommon branch is executed:

  if (elf_section_type (osec) == SHT_NULL
      && (osec->flags == isec->flags
	  || (final_link
	      && ((osec->flags ^ isec->flags)
		  & ~(SEC_LINK_ONCE | SEC_LINK_DUPLICATES | SEC_RELOC)) == 0)))

I suggest we just ignore this clause and follow the common case
behavior, which is done in this patch. Rationales to do so:

If --set-section-flags is a no-op (osec->flags == isec->flags)
(corresponds to the "readonly" test in set-section-flags.test), GNU
objcopy will require (Sec.Flags & ELF::SHF_ALLOC). [a] is essentially:

  Flags & (SectionFlag::SecContents | SectionFlag::SecLoad)

This special case is not really useful. Non-SHF_ALLOC SHT_NOBITS
sections do not make much sense and it doesn't matter if they are
SHT_NOBITS or SHT_PROGBITS.

For all other RUN lines in set-section-flags.test, the new behavior
matches GNU objcopy, i.e. this patch improves compatibility.

Differential Revision: https://reviews.llvm.org/D60189

llvm-svn: 359639
2019-05-01 00:39:31 +00:00
James Henderson
66a9d0f8c6 [llvm-objcopy][llvm-strip] Add switch to allow removing referenced sections
llvm-objcopy currently emits an error if a section to be removed is
referenced by another section. This is a reasonable thing to do, but is
different to GNU objcopy. We should allow users who know what they are
doing to have a way to produce the invalid ELF. This change adds a new
switch --allow-broken-links to both llvm-strip and llvm-objcopy to do
precisely that. The corresponding sh_link field is then set to 0 instead
of an error being emitted.

I cannot use llvm-readelf/readobj to test the link fields because they
emit an error if any sections, like the .dynsym, cannot be properly
loaded.

Reviewed by: rupprecht, grimar

Differential Revision: https://reviews.llvm.org/D60324

llvm-svn: 358649
2019-04-18 09:13:30 +00:00
Jordan Rupprecht
017deaf1ae [llvm-objcopy] Change SHT_NOBITS to SHT_PROBITS for some --set-section-flags
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
2019-04-02 16:49:56 +00:00
Jordan Rupprecht
bd95a9f46d [llvm-objcopy][NFC] Move ELF-specific logic into /ELF/ directory
llvm-svn: 357199
2019-03-28 18:27:00 +00:00
George Rimar
279898b315 [llvm-objcopy] - Strip sections before symbols.
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
2019-03-26 18:42:15 +00:00
George Rimar
e6963be317 [llvm-objcopy] - Refactor the code. NFC.
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
2019-03-25 12:34:25 +00:00
James Henderson
c040d5de25 [llvm-objcopy]Add support for *-freebsd output formats
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
2019-03-22 10:21:09 +00:00
Jake Ehrlich
5049c3422d [llvm-objcopy] Make .build-id linking atomic
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
2019-03-18 20:35:18 +00:00
Fangrui Song
3dfc3fb02b [llvm-objcopy] Delete unused parameter from replaceDebugSections. NFC
llvm-svn: 356245
2019-03-15 10:27:28 +00:00
James Henderson
b5de5e25de [llvm-objcopy]Don't implicitly strip sections in segments
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
2019-03-14 11:47:41 +00:00
James Henderson
e81f5f91b4 Revert r356129 due to greendragon bot failures
llvm-svn: 356133
2019-03-14 11:23:04 +00:00
James Henderson
c03a95d465 [llvm-objcopy]Don't implicitly strip sections in segments
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
2019-03-14 10:20:27 +00:00
Eugene Leviant
c76671b231 [llvm-objcopy] Remove unneeded checks. NFC
Differential revision: https://reviews.llvm.org/D59081

llvm-svn: 355914
2019-03-12 12:41:06 +00:00
George Rimar
d8a5c6cf19 [llvm-objcopy] - Fix --compress-debug-sections when there are relocations.
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
2019-03-11 11:01:24 +00:00
George Rimar
ade3c70537 [llvm-objcopy] - Simplify isCompressable and fix the issue relative.
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
2019-03-05 13:07:43 +00:00
Simon Pilgrim
65706cf715 Fix Wenum-compare gcc7 warning. NFCI.
llvm-svn: 354958
2019-02-27 10:19:53 +00:00
Eugene Leviant
53350d0411 [llvm-objcopy] Add --set-start, --change-start and --adjust-start
Differential revision: https://reviews.llvm.org/D58173

llvm-svn: 354854
2019-02-26 09:24:22 +00:00
Eugene Leviant
51c1f640aa [llvm-objcopy] Add --add-symbol
Differential revision: https://reviews.llvm.org/D58234

llvm-svn: 354787
2019-02-25 14:12:41 +00:00
Eugene Leviant
2db1062906 [llvm-objcopy] Add --strip-unneeded-symbol(s)
Differential revision: https://reviews.llvm.org/D58027

llvm-svn: 353919
2019-02-13 07:34:54 +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
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
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
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
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
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
16a0de2e55 [binutils] NFC: fix clang-tidy warning: use empty() instead of size() == 0
llvm-svn: 349710
2018-12-20 00:57:06 +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
Fangrui Song
e4ee066190 [llvm-objcopy] Delete redundant !Config.xx.empty() when followed by positive is_contained() check
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
2018-11-29 17:32:51 +00:00
Jordan Rupprecht
c5bae7834e [llvm-objcopy] Rename --keep to --keep-section.
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
2018-11-13 19:32:27 +00:00
Fangrui Song
e9f34b0d52 [llvm-objcopy] Don't copy Config when processing --keep
llvm-svn: 346717
2018-11-12 23:46:22 +00:00
Jordan Rupprecht
b47475c058 [llvm-objcopy] Don't apply --localize flags to common symbols
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
2018-11-01 17:26:36 +00:00