Commit Graph

5726 Commits

Author SHA1 Message Date
Ben Dunbobbin 3edca1ac1a [LLD][NFC] Refactor: BuildID hash size now computed in one place.
Differential Revision: https://reviews.llvm.org/D61078

llvm-svn: 360316
2019-05-09 08:08:09 +00:00
Fangrui Song bd086817f6 [ELF] Initialize Target before it may be dereferenced by findAux when reporting "duplicate symbol" error
for (InputFile *F : Files)
      Symtab->addFile<ELFT>(F); // if there is a duplicate symbol error

    ...

    Target = getTarget();

When parsing .debug_info in the object file (for better diagnostics),
DWARF.cpp findAux may dereference the null pointer Target

    auto *DR = dyn_cast<Defined>(&File->getRelocTargetSym(Rel));
    if (!DR) {
      // Broken debug info may point to a non-defined symbol,
      // some asan object files may also contain R_X86_64_NONE
      RelType Type = Rel.getType(Config->IsMips64EL);
      if (Type != Target->NoneRel) /// Target is null

Move the assignment of Target to an earlier place to fix this.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D61712

llvm-svn: 360305
2019-05-09 01:45:53 +00:00
Sam Clegg a1282a39ba [WebAssembly] Handle command line options consistently with the ELF backend.
Differential Revision: https://reviews.llvm.org/D61645

llvm-svn: 360266
2019-05-08 16:20:05 +00:00
Simon Atanasyan 3bdb81c26d [mips] Fix ld instruction in PLT entries on MIPS64
Use `ld` and `daddiu` instructions in MIPS64 PLT records. That fixes a
segmentation fault.

Patch by Qiao Pengcheng.

Differential Revision: https://reviews.llvm.org/D61586

llvm-svn: 360187
2019-05-07 20:26:23 +00:00
Nico Weber 54743d5767 Add typo correction for command-line flags to ELF and COFF lld drivers
For lld-link, unknown '/'-style flags are treated as filenames on POSIX
systems, so only '-'-style flags get typo correction for now. This
matches clang-cl.

PR37006.

Differential Revision: https://reviews.llvm.org/D61443

llvm-svn: 360145
2019-05-07 13:48:30 +00:00
Fangrui Song f3994e4dfa [ELF] Reorder BitcodeFiles.empty() to call thinLTOCreateEmptyIndexFiles() in only one place
It makes the --plugin-opt=obj-path= and --plugin-opt=thinlto-index-only=
behavior more consistent - the files will be created in the
BitcodeFiles.empty() case, but I assume whether it behaves this way is
not required by anyone.

LTOObj->run() cannot run with empty BitcodeFiles. There would be an error:

    ld.lld: error: No available targets are compatible with triple ""

Differential Revision: https://reviews.llvm.org/D61635

llvm-svn: 360129
2019-05-07 10:40:26 +00:00
Fangrui Song 912251e82f [PPC64] toc-indirect to toc-relative relaxation
This is based on D54720 by Sean Fertile.

When accessing a global symbol which is not defined in the translation unit,
compilers will generate instructions that load the address from the toc entry.

If the symbol is defined, non-preemptable, and addressable with a 32-bit
signed offset from the toc pointer, the address can be computed
directly. e.g.

    addis 3, 2, .LC0@toc@ha  # R_PPC64_TOC16_HA
    ld    3, .LC0@toc@l(3)   # R_PPC64_TOC16_LO_DS, load the address from a .toc entry
    ld/lwa 3, 0(3)           # load the value from the address

    .section .toc,"aw",@progbits
    .LC0: .tc var[TC],var

can be relaxed to

    addis 3,2,var@toc@ha     # this may be relaxed to a nop,
    addi  3,3,var@toc@l      # then this becomes addi 3,2,var@toc
    ld/lwa 3, 0(3)           # load the value from the address

We can delete the test ppc64-got-indirect.s as its purpose is covered by
newly added ppc64-toc-relax.s and ppc64-toc-relax-constants.s

Reviewed By: ruiu, sfertile

Differential Revision: https://reviews.llvm.org/D60958

llvm-svn: 360112
2019-05-07 04:26:05 +00:00
Fangrui Song d45df09435 [ELF] Place SHT_NOTE sections with the same alignment into one PT_NOTE
Summary:
While the generic ABI requires notes to be 8-byte aligned in ELF64, many
vendor-specific notes (from Linux, NetBSD, Solaris, etc) use 4-byte
alignment.

In a PT_NOTE segment, if 4-byte aligned notes are followed by an 8-byte
aligned note, the possible 4-byte padding may make consumers fail to
parse the 8-byte aligned note. See PR41000 for a recent report about
.note.gnu.property (NT_GNU_PROPERTY_TYPE_0).
(Note, for NT_GNU_PROPERTY_TYPE_0, the consumers should probably migrate
to PT_GNU_PROPERTY, but the alignment issue affects other notes as well.)

To fix the issue, don't mix notes with different alignments in one
PT_NOTE. If compilers emit 4-byte aligned notes before 8-byte aligned
notes, we'll create at most 2 segments.

sh_size%sh_addralign=0 is actually implied by the rule for linking
unrecognized sections (in generic ABI), so we don't have to check that.
Notes that match in name, type and attribute flags are concatenated into
a single output section. The compilers have to ensure
sh_size%sh_addralign=0 to make concatenated notes parsable.

An alternative approach is to create a PT_NOTE for each SHT_NOTE, but
we'll have to incur the sizeof(Elf64_Phdr)=56 overhead every time a new
note section is introduced.

Reviewers: ruiu, jakehehrlich, phosek, jhenderson, pcc, espindola

Subscribers: emaste, arichardson, krytarowski, fedor.sergeev, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61296

llvm-svn: 359853
2019-05-03 00:35:49 +00:00
Fangrui Song 0178cff279 [ELF] --plugin-opt=thinlto-index-only: create empty index files even if all bitcode files are lazy
Summary:
The gold plugin behavior (creating empty index files for lazy bitcode
files) was added in D46034, but it missed the case when there is no
non-lazy bitcode files, e.g.

    ld.lld -shared crti.o crtbeginS.o --start-lib bitcode.o --end-lib ...

crti.o crtbeginS.o are not bitcode, but our distributed build system
wants bitcode.o.thinlto.bc to confirm all expected outputs are created
based on all of the modules provided to the linker.

Differential Revision: https://reviews.llvm.org/D61420

llvm-svn: 359788
2019-05-02 14:05:20 +00:00
Ben Dunbobbin 6e32dd6cfd [LLD] Emit dynamic relocations for references to script symbols in -pie links
https://reviews.llvm.org/D55423 caused LLD to stop emitting dynamic relocations for references to script symbols in -pie links.

This patch fixes that regression.

https://reviews.llvm.org/D61298

llvm-svn: 359683
2019-05-01 14:07:31 +00:00
Andrew Ng 24896d304d [LLD][ELF] /DISCARD/ output sections should not be orphans
/DISCARD/ output sections were being treated as orphans. As a result, if
a /DISCARD/ output section has been assigned a PHDR, it could cause
incorrect assignment of sections to segments.

Differential Revision: https://reviews.llvm.org/D61186

llvm-svn: 359565
2019-04-30 14:31:22 +00:00
Andrew Ng 0f4c58f6f4 [LLD][ELF] Fix getRankProximity to "ignore" not live sections
This is a follow up to r358979 which made findOrphanPos only consider
live sections. Unfortunately, this required change to getRankProximity,
used by findOrphanPos, was missed.

Differential Revision: https://reviews.llvm.org/D61197

llvm-svn: 359554
2019-04-30 12:27:06 +00:00
George Rimar dee900ae59 [LLD][ELF] - Do not remove empty sections referenced in LOADADDR/ADDR commands.
This is https://bugs.llvm.org//show_bug.cgi?id=38750.

If script references empty sections in LOADADDR/ADDR commands

.empty  : { *(.empty ) }
.text   : AT(LOADADDR (.empty) + SIZEOF (.empty)) { *(.text) }
then an empty section will be removed and LOADADDR/ADDR will evaluate to null.
It is not that user may expect from using of the generic script, what is a common case.

Differential revision: https://reviews.llvm.org/D54621

llvm-svn: 359279
2019-04-26 06:59:30 +00:00
Fangrui Song 98b70f6705 [ELF] Change std::max<uint64_t> to uint32_t for section alignment
Summary:
We use `uint32_t SectionBase::Alignment` and `uint32_t
PhdrEntry::p_align` despite alignments being 64 bits in ELF64.
Fix the std::max template arguments accordingly.

The currently 160-byte InputSection will become 168 bytes if we make SectionBase::Alignment uint64_t.

Differential Revision: https://reviews.llvm.org/D61171

llvm-svn: 359268
2019-04-26 04:07:58 +00:00
Fangrui Song 5929553868 [ELF] Delete a redundant SHT_NOBITS -> SHT_PROGBITS after D60131
Differential Revision: https://reviews.llvm.org/D61006

llvm-svn: 359099
2019-04-24 14:44:07 +00:00
Fangrui Song 513d3658e7 [PPC64] Consider localentry offset when computing branch distance
Summary:
We don't take localentry offset into account, and thus may fail to
create a long branch when the gap is just a few bytes smaller than 2^25.

relocation R_PPC64_REL24 out of range: 33554432 is not in [-33554432, 33554431]
relocation R_PPC64_REL24 out of range: 33554436 is not in [-33554432, 33554431]

Fix that by adding the offset to the symbol VA.

Differential Revision: https://reviews.llvm.org/D61058

llvm-svn: 359094
2019-04-24 14:03:30 +00:00
Fangrui Song 74780852dc [ELF] Fix a gcc -Wextra warning
Extracted from D61046.

warning: enumeral and non-enumeral type in conditional expression [-Wextra]

Cast SHF_ALLOC to avoid that.

llvm-svn: 359070
2019-04-24 05:33:33 +00:00
Andrew Ng ccba42c7eb [ELF] Change default output section type to SHT_PROGBITS
This fixes an issue where a symbol only section at the start of a
PT_LOAD segment, causes incorrect alignment of the file offset for the
start of the segment which results in the output of an invalid ELF.

SHT_PROGBITS was the default output section type in the past.

Differential Revision: https://reviews.llvm.org/D60131

llvm-svn: 358981
2019-04-23 12:38:52 +00:00
Andrew Ng 98c858a23b [ELF] Change findOrphanPos to only consider live sections
This patch changes the behaviour of findOrphanPos to only consider live
sections when placing orphan sections. This used to be how it behaved in
the past.

Differential Revision: https://reviews.llvm.org/D60273

llvm-svn: 358979
2019-04-23 12:17:15 +00:00
Fangrui Song d986e41fe4 [PPC64] Allow R_PPC64_DTPREL* to preemptable local-dynamic symbols
Similar to D60945.

Differential Revision: https://reviews.llvm.org/D60994

llvm-svn: 358950
2019-04-23 06:31:44 +00:00
Fangrui Song 32c0ebe615 Use llvm::stable_sort
Make some small adjustment while touching the code: make parameters
const, use less_first(), etc.

Differential Revision: https://reviews.llvm.org/D60989

llvm-svn: 358943
2019-04-23 02:42:06 +00:00
George Rimar 3275742898 [LLD][ELF] - Do not forget to use ch_addralign field after decompressing the sections.
LLD did not use ELF::Chdr::ch_addralign for decompressed sections.
This resulted in a broken output.

Fixes https://bugs.llvm.org/show_bug.cgi?id=40482.

Differential revision: https://reviews.llvm.org/D60959

llvm-svn: 358885
2019-04-22 13:40:42 +00:00
George Rimar f902250fc1 [LLD][ELF] - Handle quoted strings in the linker scripts correctly.
This is the https://bugs.llvm.org/show_bug.cgi?id=41356,

Seems it is kind of unusual case but it is possible to
have sections that require quotes for their namings.
Like "aaa bbb".

This patch adds support for those.

Differential revision: https://reviews.llvm.org/D60901

llvm-svn: 358874
2019-04-22 07:57:07 +00:00
Fangrui Song bc4b159bb1 [ELF][X86] Allow R_386_TLS_LDO_32 and R_X86_64_DTPOFF{32,64} to preemptable local-dynamic symbols
Summary:
Fixes PR35242. A simplified reproduce:

    thread_local int i; int f() { return i; }

% {g++,clang++} -fPIC -shared -ftls-model=local-dynamic -fuse-ld=lld a.cc
ld.lld: error: can't create dynamic relocation R_X86_64_DTPOFF32 against symbol: i in readonly segment; recompile object files with -fPIC or pass '-Wl,-z,notext' to allow text relocations in the output

In isStaticLinkTimeConstant(), Syn.IsPreemptible is true, so it is not
seen as a constant. The error is then issued in processRelocAux().

A symbol of the local-dynamic TLS model cannot be preempted but it can
preempt symbols of the global-dynamic TLS model in other DSOs.
So it makes some sense that the variable is not static.

This patch fixes the linking error by changing getRelExpr() on
R_386_TLS_LDO_32 and R_X86_64_DTPOFF{32,64} from R_ABS to R_DTPREL.
R_PPC64_DTPREL_* and R_MIPS_TLS_DTPREL_* need similar fixes, but they are not handled in this patch.

As a bonus, we use `if (Expr == R_ABS && !Config->Shared)` to find
ld-to-le opportunities. R_ABS is overloaded here for such STT_TLS symbols.
A dedicated R_DTPREL is clearer.

Differential Revision: https://reviews.llvm.org/D60945

llvm-svn: 358870
2019-04-22 03:10:40 +00:00
Fangrui Song e1f3191a0d [ELF][X86] Rename R_RELAX_TLS_GD_TO_IE_END to R_RELAX_TLS_GD_TO_IE_GOTPLT
Summary:
This relocation type is used by R_386_TLS_GD. Its formula is the same as
R_GOTPLT (e.g R_X86_64_GOT{32,64} R_386_TLS_GOTIE). Rename it to be clearer.

Differential Revision: https://reviews.llvm.org/D60941

llvm-svn: 358868
2019-04-22 02:48:37 +00:00
George Rimar 69186f82f3 [LLD][ELF] - A fix for "linker script assignment loses relative nature of section" bug.
This is https://bugs.llvm.org//show_bug.cgi?id=39857.
I added the comment with much more details to the bug page,
the short version is below.

The following script and code demonstrates the issue:

aliasto__text = __text;
 SECTIONS {
  .text 0x1000 : { __text = . ; *(.text) }
 }
...
call aliasto__text

LLD fails with "cannot refer to absolute symbol: aliasto__text" error.
It happens because at the moment of scanning the relocations
we do not yet assign the correct/final/any section value for the symbol aliasto__text.
I made a change to Relocations.cpp to fix that.

Also, I had to remove the symbol-location.s test case completely, because now it does not
trigger any error. Since now all linker scripts symbols are resolved to constants, no
errors can be triggered at all it seems. I checked that it is consistent with the behavior
of bfd and gold (they do not trigger errors for the case from symbol-location.s), so it should
be OK. I.e. at least it is probably not the best possible, but natural behavior we obtained.

Differential revision: https://reviews.llvm.org/D55423

llvm-svn: 358652
2019-04-18 10:00:37 +00:00
Fangrui Song 3deff86657 [ELF] Respect NonAlloc when copying flags from the previous sections
Summary:
If the output section contains only symbol assignments, we copy flags
from the previous sections. Don't set SHF_ALLOC if NonAlloc is true.

We also have to change the type from SHT_NOBITS to SHT_PROGBITS.
In ld.bfd, bfd_elf_get_default_section_type maps non-alloctable sections to SHT_PROGBITS.
Non-alloctable SHT_NOBITS sections do not make sense.

Fixes PR38626

Differential Revision: https://reviews.llvm.org/D59986

llvm-svn: 358650
2019-04-18 09:22:05 +00:00
George Rimar da49faf15e [LLD][ELF] - Fix the different behavior of the linker script symbols on different platforms.
This generalizes code and also fixes the broken behavior shown in
one of our test cases for some targets, like x86-64.

The issue occurs when the forward declarations are used in the script.
One of the samples is:

SECTIONS {
  foo = ADDR(.text) - ABSOLUTE(ADDR(.text));
};

In that case, we have a broken output when output target does
not use thunks. That happens because thunks creating code
(called from maybeAddThunks)
calls Script->assignAddresses() at least one more time,
what fixups the values. As a result final symbols values can
be different on AArch64 and x86, for example.

In this patch, I generalize and rename maybeAddThunks to
finalizeAddressDependentContent and now it is used and called
by all targets.

Differential revision: https://reviews.llvm.org/D55550

llvm-svn: 358646
2019-04-18 08:15:54 +00:00
Fangrui Song 957c356ffe [ELF] Place SectionPiece::{Live,Hash} bit fields together
Summary:
We access Live and OutputOff (which may share the same memory location)
concurrently in 2 parallelForEachN loops. Separating them avoids subtle
data races like D41884/PR35788. This patch places Live and Hash
together.

2 reasons this is appealing:

1) Hash is immutable. Live is almost read-only - only written once in MarkLive.cpp where
   Hash is not accessed
2) we already discard low bits of Hash to decide ShardID. It doesn't
   matter much if we make 32-bit Hash to 31-bit.

   For a huge internal clang -O3 executable (1.6GiB),
   `Strings` in StringTableBuilder::finalizeStringTable contains at most 310253 elements.
   The expected number of pair-wise collisions 2^(-31) * C(310253,2) ~= 22.41 is too small to have a negative impact on performance.
   Actually, my benchmark shows there is actually a minor performance improvement.

Differential Revision: https://reviews.llvm.org/D60765

llvm-svn: 358645
2019-04-18 07:46:09 +00:00
Rui Ueyama 14ef9b30b6 lld: elf: Fix sections with explict addresses in regions
Patch by Gabriel Smith.

The address for a section would be evaluated before the region was
switched to. Because of this, the position within the region would not
be updated. After the region is swapped to the dot would be set to the
out of date position within the region, undoing the section address
evaluation.

To fix this, the region is swapped to before the section's address is
evaluated. As part of the fallout of this, expandMemoryRegions needed
to be gated in setDot on the condition that the evaluated address is
less than the dot. This is for the case where sections are not listed
from lowest address to highest address.

Finally, a test for the case where sections are listed "out of order"
was added.

Differential Revision: https://reviews.llvm.org/D60744

llvm-svn: 358638
2019-04-18 02:32:12 +00:00
Fangrui Song 2bc3a19a49 [ELF] Use llvm::bsearch. NFC
Differential Revision: https://reviews.llvm.org/D60813

llvm-svn: 358565
2019-04-17 08:00:46 +00:00
Peter Collingbourne 97d25e068f ELF: Move build id computation to Writer. NFCI.
With partitions, each partition should have the same build id. This means
that the build id needs to be only computed once, otherwise we will end up
with different build ids in each partition as a result of the file contents
changing. This change moves the computation of the build id into Writer so
that it only happens once.

Differential Revision: https://reviews.llvm.org/D60342

llvm-svn: 358536
2019-04-16 22:45:14 +00:00
Fangrui Song abc068fc59 [ELF] Fix typo: .symtab_shndxr -> .symtab_shndx
The typo was introduced to llvm MC in rL204769 (fixed in rL358247) and then to lld.

Also, for relocatable-many-sections.s, the size of .symtab changed at some point and the formula needs update.

llvm-svn: 358248
2019-04-12 02:20:52 +00:00
Rui Ueyama 3a8bb7cd2c Discard debuginfo for object files empty after GC
Patch by Robert O'Callahan.

Rust projects tend to link in all object files from all dependent
libraries and rely on --gc-sections to strip unused code and data.
Unfortunately --gc-sections doesn't currently strip any debuginfo
associated with GC'ed sections, so lld links in the full debuginfo from
all dependencies even if almost all that code has been discarded. See
https://github.com/rust-lang/rust/issues/56068 for some details.

Properly stripping debuginfo for discarded sections would be difficult,
but a simple approach that helps significantly is to mark debuginfo
sections as live only if their associated object file has at least one
live code/data section. This patch does that. In a (contrived but not
totally artificial) Rust testcase linked above, it reduces the final
binary size from 46MB to 5.1MB.

Differential Revision: https://reviews.llvm.org/D54747

llvm-svn: 358069
2019-04-10 10:37:10 +00:00
Rui Ueyama 0c01607bbf Rename a variable and add a comment.
llvm-svn: 358049
2019-04-10 06:32:05 +00:00
Chih-Mao Chen 949570ce39 [RISCV] Fix range check for HI20/LO12/RVC_LUI relocations
The code previously specified a 32-bit range for R_RISCV_HI20 and
R_RISCV_LO12_[IS], however this is incorrect as the maximum offset on
RV64 that can be formed from the immediate of lui and the displacement
of an I-type or S-type instruction is -0x80000800 to 0x7ffff7ff. There
is also the same issue with a c.lui and LO12 pair, whose actual
addressable range should be -0x20800 to 0x1f7ff.

The tests will be included in the next patch that converts all RISC-V
tests to use llvm-mc instead of yaml2obj, as assembler support has
matured enough to write tests in them.

Differential Revision: https://reviews.llvm.org/D60414

llvm-svn: 357995
2019-04-09 11:39:23 +00:00
Rui Ueyama f432fa6eee De-template SymbolTable::addShared.
Because of r357925, this member function doesn't have to be a
template of ELFT.

llvm-svn: 357982
2019-04-09 08:52:00 +00:00
Peter Collingbourne d3e207057f ELF: Move verneed tracking data structures out of VersionNeedSection.
For partitions I intend to use the same set of version indexes in
each partition for simplicity. Since each partition will need its own
VersionNeedSection this will require moving the verneed tracking out of
VersionNeedSection. The way I've done this is to move most of the tracking
into SharedFile. What will eventually become the per-partition tracking
still lives in VersionNeedSection.

As a bonus the code gets a little simpler and more consistent with how we
handle verdef.

Differential Revision: https://reviews.llvm.org/D60307

llvm-svn: 357926
2019-04-08 17:48:05 +00:00
Peter Collingbourne cc1618e668 ELF: De-template SharedFile. NFCI.
Differential Revision: https://reviews.llvm.org/D60305

llvm-svn: 357925
2019-04-08 17:35:55 +00:00
Rui Ueyama 4af8d47d05 Fix -emit-reloc against local symbols.
Previously, we drop symbols starting with .L from the symbol table, so
if there is a relocation that refers a .L symbol, it ended up
referencing a null -- which happened to be interpreted as an absolute
symbol.

This patch copies all symbols including local ones if -emit-reloc is
given.

Fixes https://bugs.llvm.org/show_bug.cgi?id=41385

Differential Revision: https://reviews.llvm.org/D60306

llvm-svn: 357885
2019-04-08 06:45:07 +00:00
Peter Collingbourne 883ab235ee ELF: De-template ELFFileBase. NFCI.
Differential Revision: https://reviews.llvm.org/D60304

llvm-svn: 357806
2019-04-05 20:16:26 +00:00
Peter Collingbourne ad4376e8af ELF: Simplify. NFCI.
Differential Revision: https://reviews.llvm.org/D60299

llvm-svn: 357739
2019-04-05 01:31:40 +00:00
Rui Ueyama 7c28937baf Remove redundant parameters. NFC.
llvm-svn: 357738
2019-04-05 01:30:09 +00:00
Peter Collingbourne 8238604259 ELF: Move SymtabSHNDX and getSectionIndex() to ObjFile. NFCI.
Differential Revision: https://reviews.llvm.org/D60244

llvm-svn: 357670
2019-04-04 03:13:51 +00:00
Peter Collingbourne a9e847238e ELF: Perform per-section .ARM.exidx processing during combineEhFrameSections(). NFCI.
And rename the function to combineEhSections(). This makes the processing
of .ARM.exidx even more similar to .eh_frame and means that we can avoid an
additional loop over InputSections.

Differential Revision: https://reviews.llvm.org/D60026

llvm-svn: 357417
2019-04-01 18:01:18 +00:00
Fangrui Song d83fb24533 [ELF] Rename SyntheticSection::empty to more appropriate isNeeded() with opposite meaning
Summary:
Some synthetic sections can be empty while still being needed, thus they
can't be removed by removeUnusedSyntheticSections(). Rename this member
function to more appropriate isNeeded() with the opposite meaning.

No functional change intended.

Reviewers: ruiu, espindola

Reviewed By: ruiu

Subscribers: jhenderson, grimar, emaste, arichardson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59982

llvm-svn: 357377
2019-04-01 08:16:08 +00:00
Rui Ueyama a77ea59c4d Simplify. NFC.
llvm-svn: 357373
2019-04-01 00:25:17 +00:00
Rui Ueyama 68b9f45fee Replace `typedef A B` with `using B = A`. NFC.
I did this using Perl.

Differential Revision: https://reviews.llvm.org/D60003

llvm-svn: 357372
2019-04-01 00:11:24 +00:00
Fangrui Song 8048fe2b8c [ELF][MachO][wasm] Simplify range-style std::find{,_if} with STLExtras.h utilities. NFC
llvm-svn: 357269
2019-03-29 16:21:16 +00:00
Rui Ueyama 6528f2eac9 Remove a duplicate assignment. NFC.
llvm-svn: 357223
2019-03-28 23:53:38 +00:00
Rui Ueyama f28825bc06 Create an instance of Target after reading all input files. NFC.
This change itself doesn't mean anything, but it helps D59780 because
in patch, we don't know whether we need to create a CET-aware PLT or
not until we read all input files.

llvm-svn: 357194
2019-03-28 17:38:53 +00:00
Rui Ueyama 8521ba37d7 Make a member function a non-member function.
Since this member function doesn't use anything in the class,
it doesn't have to be a member of the class.

llvm-svn: 357193
2019-03-28 17:35:00 +00:00
Rui Ueyama 676d25ab94 De-template X86_64TargetInfo. NFC.
llvm-svn: 357191
2019-03-28 17:31:12 +00:00
Rui Ueyama c694633a12 Make TargetInfo const. NFC.
We do not mutate a TargetInfo instance after creating it. This change
makes it explicit.

llvm-svn: 357185
2019-03-28 17:05:09 +00:00
Peter Smith 3ce9af9370 [ELF][ARM] Recommit Redesign of .ARM.exidx handling to use a SyntheticSection
Recommit r356666 with fixes for buildbot failure, as well as handling for
--emit-relocs, which we decide not to emit any relocation sections as the
table is already position independent and an offline tool can deduce the
relocations.

Instead of creating extra Synthetic .ARM.exidx sections to account for
gaps in the table, create a single .ARM.exidx SyntheticSection that can
derive the contents of the gaps from a sorted list of the executable
InputSections. This has the benefit of moving the ARM specific code for
SyntheticSections in SHF_LINK_ORDER processing and the table merging code
into the ARM specific SyntheticSection. This also makes it easier to create
EXIDX_CANTUNWIND table entries for executable InputSections that don't
have an associated .ARM.exidx section.

Fixes pr40277

Differential Revision: https://reviews.llvm.org/D59216

llvm-svn: 357160
2019-03-28 11:10:20 +00:00
Rui Ueyama a0a50a7a5b Inline a trivial function. NFC.
I found that hiding this particular actual expression doesn't help
readers understand the code. So I remove and inline that function.

llvm-svn: 357140
2019-03-28 01:37:48 +00:00
Rui Ueyama 432030e843 [ELF] Dump symbols ordered by profiled guided section layout to file.
Patch by Tiancong Wang.

In D36351, Call-Chain Clustering (C3) heuristic is implemented with
option --call-graph-ordering-file <file>.
This patch adds a flag --print-symbol-order=<file> to LLD, and when
specified, it prints out the symbols ordered by the heuristics to the
file. The symbols printout is helpful to those who want to understand
the heuristics and want to reproduce the ordering with
--symbol-ordering-file in later pass.

Differential Revision: https://reviews.llvm.org/D59311

llvm-svn: 357133
2019-03-27 23:52:22 +00:00
Fangrui Song 210949a221 [ELF] Change GOT*_FROM_END (relative to end(.got)) to GOTPLT* (start(.got.plt))
Summary:
This should address remaining issues discussed in PR36555.

Currently R_GOT*_FROM_END are exclusively used by x86 and x86_64 to
express relocations types relative to the GOT base. We have
_GLOBAL_OFFSET_TABLE_ (GOT base) = start(.got.plt) but end(.got) !=
start(.got.plt)

This can have problems when _GLOBAL_OFFSET_TABLE_ is used as a symbol, e.g.
glibc dl_machine_dynamic assumes _GLOBAL_OFFSET_TABLE_ is start(.got.plt),
which is not true.

  extern const ElfW(Addr) _GLOBAL_OFFSET_TABLE_[] attribute_hidden;
  return _GLOBAL_OFFSET_TABLE_[0]; // R_X86_64_GOTPC32

In this patch, we

* Change all GOT*_FROM_END to GOTPLT* to fix the problem.
* Add HasGotPltOffRel to denote whether .got.plt should be kept even if
  the section is empty.
* Simplify GotSection::empty and GotPltSection::empty by setting
  HasGotOffRel and HasGotPltOffRel according to GlobalOffsetTable early.

The change of R_386_GOTPC makes X86::writePltHeader simpler as we don't
have to compute the offset start(.got.plt) - Ebx (it is constant 0).

We still diverge from ld.bfd (at least in most cases) and gold in that
.got.plt and .got are not adjacent, but the advantage doing that is
unclear.

Reviewers: ruiu, sivachandra, espindola

Subscribers: emaste, mehdi_amini, arichardson, dexonsmith, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59594

llvm-svn: 356968
2019-03-25 23:46:19 +00:00
Rui Ueyama e6c24299d2 Use a class instead of lambda-based callbacks to organize garbage collector.
lld's mark-sweep garbage collector was written in the visitor pattern.
There are functions that traverses a given graph, and the functions calls
callback functions to dispatch according to node type.

The code was originaly pretty simple, and lambdas worked pretty
well. However, as we add more features to the garbage collector, that became
more like a callback hell. We now have a callback function that wraps
another callback function, for example. It is not easy to follow the flow of
the control.

This patch rewrites it as a regular class. What was once a lambda is now a
regular class member function. I think this change fixes the readability
issue.

No functionality change intended.

Differential Revision: https://reviews.llvm.org/D59800

llvm-svn: 356966
2019-03-25 23:28:47 +00:00
Rui Ueyama d2e0ed7755 Simplify PltSection.
Previously, `Entries` contains pairs of symbols and their indices.
The indices are always 0, x, 2x, 3x, ..., where x is the size of
relocation entry. We didn't have to store that values because we can
compute them when we consume them.

llvm-svn: 356812
2019-03-22 21:17:25 +00:00
Fangrui Song dc6c0cf94d [DWARF] Refactor RelocVisitor and fix computation of SHT_RELA-typed relocation entries
Summary: This is the lld-side change of D57939

Reviewers: echristo, dblaikie, ruiu, espindola

Reviewed By: echristo, ruiu

Subscribers: jdoerfert, emaste, arichardson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57940

llvm-svn: 356730
2019-03-22 02:43:17 +00:00
Peter Smith 54dab70bb7 [ELF][ARM] Revert Redesign of .ARM.exidx handling to use a SyntheticSection
There is a reproducible buildbot failure (segfault) on the 2 stage
clang-cmake-armv8-lld bot. Reverting while I investigate.

Differential Revision: https://reviews.llvm.org/D59216

llvm-svn: 356684
2019-03-21 17:17:54 +00:00
Peter Smith d3511a214e [ELF][ARM] Redesign of .ARM.exidx handling to use a SyntheticSection
Instead of creating extra Synthetic .ARM.exidx sections to account for
gaps in the table, create a single .ARM.exidx SyntheticSection that can
derive the contents of the gaps from a sorted list of the executable
InputSections. This has the benefit of moving the ARM specific code for
SyntheticSections in SHF_LINK_ORDER processing and the table merging code
into the ARM specific SyntheticSection. This also makes it easier to create
EXIDX_CANTUNWIND table entries for executable InputSections that don't
have an associated .ARM.exidx section.

Fixes pr40277

Differential Revision: https://reviews.llvm.org/D59216

llvm-svn: 356666
2019-03-21 14:06:40 +00:00
Fangrui Song 1092fc9057 [ELF] Allow sh_entsize to be unrelated to sh_addralign and not a power of 2
Summary:
This implements Rui Ueyama's idea in PR39044.
I've checked that ld.bfd and gold do not have the power-of-2 requirement
and do not require sh_entsize to be a multiple of sh_align.

Now on the updated test merge-entsize.s, all the 3 linkers happily
create .rodata that is not 3-byte aligned.

This has a use case in Linux arch/x86/crypto/sha512-avx2-asm.S
It uses sh_entsize of 640, which is not a power of 2.
See https://github.com/ClangBuiltLinux/linux/issues/417

Reviewers: ruiu, espindola

Reviewed By: ruiu

Subscribers: nickdesaulniers, E5ten, emaste, arichardson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59478

llvm-svn: 356428
2019-03-18 23:49:18 +00:00
Siva Chandra 1915e2be93 [ELF] Emit weak-undef symbols in .dynsym of a PIE binary only if linked against shared libs.
Reviewers: espindola

Subscribers: emaste, arichardson, MaskRay, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59275

llvm-svn: 356374
2019-03-18 15:32:57 +00:00
Fangrui Song 6778b53e95 [ELF] De-virtualize findOrphanPos, excludeLibs and handleARMTlsRelocation
llvm-svn: 356331
2019-03-17 13:53:42 +00:00
Fangrui Song f9695e166b [ELF] Delete unused forward declarations and unused DynamicReloc::getInputSec(). NFC
llvm-svn: 356239
2019-03-15 07:16:39 +00:00
Fangrui Song 76a7ecb3ae [ELF] De-template wrapSymbols, isReserved and addGotEntry. NFC
llvm-svn: 356237
2019-03-15 06:58:23 +00:00
Fangrui Song e8710ef1fb [ELF] Split RW PT_LOAD on the PT_GNU_RELRO boundary
Summary:
Based on Peter Collingbourne's suggestion in D56828.

Before D56828: PT_LOAD(.data PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) .bss)
Old:           PT_LOAD(PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) .data .bss)
New:           PT_LOAD(PT_GNU_RELRO(.data.rel.ro .bss.rel.ro)) PT_LOAD(.data. .bss)

The new layout reflects the runtime memory mappings.
By having two PT_LOAD segments, we can utilize the NOBITS part of the
first PT_LOAD and save bytes for .bss.rel.ro.

.bss.rel.ro is currently small and only used by copy relocations of
symbols in read-only segments, but it can be used for other purposes in
the future, e.g. if a relro section's statically relocated data is all
zeros, we can move it to .bss.rel.ro.

Reviewers: espindola, ruiu, pcc

Reviewed By: ruiu

Subscribers: nemanjai, jvesely, nhaehnle, javed.absar, kbarton, emaste, arichardson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58892

llvm-svn: 356226
2019-03-15 01:29:57 +00:00
Rui Ueyama cc8e4e839f Make a hack for LTO work only when you are actually doing LTO.
We allow an archive file without symbol table as a linker input as a
workaround for a very common error in LTO build. But that logic worked
even for an archive file containing non-bitcode files, which is not
expected. This patch limits that workaround to one that contains only
bitcode files.

Differential Revision: https://reviews.llvm.org/D59373

llvm-svn: 356186
2019-03-14 18:21:32 +00:00
Fangrui Song 07f8daf05e [ELF] Simplify RelRo, TLS, NOBITS section ranks and make RW PT_LOAD start with RelRo
Old: PT_LOAD(.data | PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) | .bss)
New: PT_LOAD(PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) | .data .bss)

The placement of | indicates page alignment caused by PT_GNU_RELRO. The
new layout has simpler rules and saves space for many cases.

Old size: roundup(.data) + roundup(.data.rel.ro)
New size: roundup(.data.rel.ro + .bss.rel.ro) + .data

Other advantages:

* At runtime the 3 memory mappings decrease to 2.
* start(PT_TLS) = start(PT_GNU_RELRO) = start(RW PT_LOAD). This
  simplifies binary manipulation tools.
  GNU strip before 2.31 discards PT_GNU_RELRO if its
  address is not equal to the start of its associated PT_LOAD.
  This has been fixed by https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f2731e0c374e5323ce4cdae2bcc7b7fe22da1a6f
  But with this change, we will be compatible with GNU strip before 2.31
* Before, .got.plt (non-relro by default) was placed before .got (relro
  by default), which made it impossible to have _GLOBAL_OFFSET_TABLE_
  (start of .got.plt on x86-64) equal to the end of .got (R_GOT*_FROM_END)
  (https://bugs.llvm.org/show_bug.cgi?id=36555). With the new ordering, we
  can improve on this regard if we'd like to.

Reviewers: ruiu, espindola, pcc

Subscribers: emaste, arichardson, llvm-commits, joerg, jdoerfert

Differential Revision: https://reviews.llvm.org/D56828

llvm-svn: 356117
2019-03-14 03:47:45 +00:00
Simon Atanasyan 2e855675eb [mips] Remove redundant setup of less-significant bit. NFC
The less-significant bit for microMIPS symbols configured
in the `getSymVA` function. Do not need to setup it once again.

llvm-svn: 356058
2019-03-13 16:00:35 +00:00
Francis Visoiu Mistrih dd42236c6c Reland "[Remarks] Add -foptimization-record-passes to filter remark emission"
Currently we have -Rpass for filtering the remarks that are displayed as
diagnostics, but when using -fsave-optimization-record, there is no way
to filter the remarks while generating them.

This adds support for filtering remarks by passes using a regex.
Ex: `clang -fsave-optimization-record -foptimization-record-passes=inline`

will only emit the remarks coming from the pass `inline`.

This adds:

* `-fsave-optimization-record` to the driver
* `-opt-record-passes` to cc1
* `-lto-pass-remarks-filter` to the LTOCodeGenerator
* `--opt-remarks-passes` to lld
* `-pass-remarks-filter` to llc, opt, llvm-lto, llvm-lto2
* `-opt-remarks-passes` to gold-plugin

Differential Revision: https://reviews.llvm.org/D59268

Original llvm-svn: 355964

llvm-svn: 355984
2019-03-12 21:22:27 +00:00
Peter Collingbourne 8a28673a2e ELF: Don't add .dynamic strings to .dynstr early.
This does not appear to be necessary because StringTableSection does not
need to be finalized, which also means that we can remove the call to
finalizeSynthetic on .dynstr.

Differential Revision: https://reviews.llvm.org/D59240

llvm-svn: 355977
2019-03-12 20:58:34 +00:00
Francis Visoiu Mistrih 1d6c47ad2b Revert "[Remarks] Add -foptimization-record-passes to filter remark emission"
This reverts commit 20fff32b7d.

llvm-svn: 355976
2019-03-12 20:54:18 +00:00
Peter Collingbourne e2b8c40a77 ELF: Use bump pointer allocator for uncompressed section buffers. NFCI.
This shaves another word off SectionBase and makes it possible to clone a
section using the implicit copy constructor.

This basically reverts r311056, which removed the mutex in order to
make the code easier to understand. On balance I think it's probably more
straightforward to have a mutex here than to have an unusual copy constructor
in SectionBase.

Differential Revision: https://reviews.llvm.org/D59269

llvm-svn: 355966
2019-03-12 20:32:30 +00:00
Francis Visoiu Mistrih 20fff32b7d [Remarks] Add -foptimization-record-passes to filter remark emission
Currently we have -Rpass for filtering the remarks that are displayed as
diagnostics, but when using -fsave-optimization-record, there is no way
to filter the remarks while generating them.

This adds support for filtering remarks by passes using a regex.
Ex: `clang -fsave-optimization-record -foptimization-record-passes=inline`

will only emit the remarks coming from the pass `inline`.

This adds:

* `-fsave-optimization-record` to the driver
* `-opt-record-passes` to cc1
* `-lto-pass-remarks-filter` to the LTOCodeGenerator
* `--opt-remarks-passes` to lld
* `-pass-remarks-filter` to llc, opt, llvm-lto, llvm-lto2
* `-opt-remarks-passes` to gold-plugin

Differential Revision: https://reviews.llvm.org/D59268

llvm-svn: 355964
2019-03-12 20:28:50 +00:00
Peter Collingbourne 2da7b32684 ELF: Simplify. NFCI.
We don't need to take a slice of SectionCommands in addOrphanSections()
because it is not modified until the end of the function.

Differential Revision: https://reviews.llvm.org/D59239

llvm-svn: 355954
2019-03-12 19:19:23 +00:00
George Rimar 43b6689e64 [LLD][ELF] - Show symbols visibility in "undefined symbol..." error messages.
This teaches LLD to report visibility when showing undefined symbol errors
and fixes https://bugs.llvm.org/show_bug.cgi?id=40770.

Differential revision: https://reviews.llvm.org/D58577

llvm-svn: 355909
2019-03-12 11:10:29 +00:00
Peter Collingbourne b5a307fa24 ELF: Remove dead code. NFCI.
The Live bit is already set to false by SectionBase.

Differential Revision: https://reviews.llvm.org/D59052

llvm-svn: 355893
2019-03-12 02:18:03 +00:00
Eli Friedman 3751ae4a94 [ELF] Print a better error for an archive containing a non-ELF file.
Hopefully gives a more readable error message for the most obvious
mistake.

Differential Revision: https://reviews.llvm.org/D59170

llvm-svn: 355888
2019-03-12 01:24:39 +00:00
Rui Ueyama 033c4d2126 Include an archive file name in an error message for a corrupted file.
Differential Revision: https://reviews.llvm.org/D59212

llvm-svn: 355886
2019-03-12 00:24:34 +00:00
Rong Xu f92e59cbba [PGO] Add options for context-sensitive PGO
Add lld options for CSPGO (context-sensitive PGO).

Differential Revision: https://reviews.llvm.org/D56675

llvm-svn: 355876
2019-03-11 22:51:38 +00:00
Rui Ueyama 7fd99fc475 Fail early if an output file is not writable
Fixes https://bugs.llvm.org/show_bug.cgi?id=36478

Differential Revision: https://reviews.llvm.org/D43664

llvm-svn: 355834
2019-03-11 16:30:55 +00:00
Sam Clegg d15a4154a8 [WebAssembly] Don't mark lazy symbols as `IsUsedInRegularObj`
This matches the ELF does.  Update the comment in ELF/Symbols.h and
duplicate it in wasm/Symbols.h

This a followup on rL355580 and rL355577.

Differential Revision: https://reviews.llvm.org/D59075

llvm-svn: 355737
2019-03-08 21:10:48 +00:00
Peter Collingbourne dfbb9a793e ELF: Reduce the size of InputSectionBase by two words. NFCI.
- The Assigned bit was previously taking a word on its own. Move
  it into the bit fields in SectionBase.
- NumRelocations and AreRelocsRela were previously also taking up
  a word despite only using half of it. Move them into the alignment gap
  after SectionBase's fields.

Differential Revision: https://reviews.llvm.org/D59044

llvm-svn: 355622
2019-03-07 18:48:12 +00:00
Peter Collingbourne 5ee9abd4c8 ELF: De-template OutputSection::finalize() and MipsGotSection::build(). NFCI.
Differential Revision: https://reviews.llvm.org/D58810

llvm-svn: 355479
2019-03-06 03:07:57 +00:00
Peter Collingbourne 704dfd6e28 ELF: Extract a non-ELFT base class for VersionNeedSection.
We're going to need a separate VersionNeedSection for each partition, and
the partition data structure won't be templated.

With this the VersionTableSection class no longer needs ELFT, so detemplate it.

Differential Revision: https://reviews.llvm.org/D58808

llvm-svn: 355478
2019-03-06 03:07:48 +00:00
Peter Collingbourne 16d9a0acfd ELF: Change FileSize back to a uint64_t.
This lets us detect file size overflows when creating a 64-bit binary on
a 32-bit machine.

Differential Revision: https://reviews.llvm.org/D58840

llvm-svn: 355218
2019-03-01 18:53:41 +00:00
Peter Smith 22ce712c19 [ELF][ARM] Fix clang-armv7-linux-build-cache builds of LLD [NFC]
r355153 introduced a build failure on a build bot that uses clang natively
on an armv7-a machine. This a temporary fix to use size_t rather than
uint64_t.

llvm-svn: 355195
2019-03-01 10:52:25 +00:00
Peter Collingbourne 7fb9eabda5 ELF: Write .eh_frame_hdr explicitly after writing .eh_frame.
This lets us remove the special case from Writer::writeSections(), and also
fixes a bug where .eh_frame_hdr isn't necessarily written in the correct
order if a linker script moves .eh_frame and .eh_frame_hdr into the same
output section.

Differential Revision: https://reviews.llvm.org/D58795

llvm-svn: 355153
2019-02-28 23:11:35 +00:00
Alexey Lapshin 77fc1f6049 [DebugInfo] add SectionedAddress to DebugInfo interfaces.
That patch is the fix for https://bugs.llvm.org/show_bug.cgi?id=40703
   "wrong line number info for obj file compiled with -ffunction-sections"
   bug. The problem happened with only .o files. If object file contains
   several .text sections then line number information showed incorrectly.
   The reason for this is that DwarfLineTable could not detect section which
   corresponds to specified address(because address is the local to the
   section). And as the result it could not select proper sequence in the
   line table. The fix is to pass SectionIndex with the address. So that it
   would be possible to differentiate addresses from various sections. With
   this fix llvm-objdump shows correct line numbers for disassembled code.

   Differential review: https://reviews.llvm.org/D58194

llvm-svn: 354972
2019-02-27 13:17:36 +00:00
George Rimar cc19dc75fb [LLD][ELF] - Improve "sh_addralign is not a power of 2" diagnostics.
This patch removes the precompiled binary from inputs,
replacing it with a YAML. And teaches LLD to report a
section name in case of such error.

Differential revision: https://reviews.llvm.org/D58670

llvm-svn: 354959
2019-02-27 10:28:23 +00:00
Bill Wendling 01706bda5b Output ELF files after ThinLTO is run.
Summary:
The gold linker allowed you to output the ELF files after LTO was run. It did
it by using the 'obj-path' option. This replicates that behavior.

Reviewers: espindola, ruiu, MaskRay, pcc

Reviewed By: MaskRay, pcc

Subscribers: grimar, emaste, inglorion, arichardson, steven_wu, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D56046

llvm-svn: 354917
2019-02-26 19:29:14 +00:00
Peter Smith 777e1cfdc3 [ELF][ARM] Accept and ignore -p and -no-pipleline-knowledge
The linux kernel uses an old flag -p/-no-pipeline-knowledge that is
accepted by bfd and gold but ignored by modern versions of them. The
original option is very old and is pre-ABI, it sometimes comes up in
code-bases that had support for pre ABI toolchains. The Linux kernel uses
it in 3 places in the ARM specific section.

Differential Revision: https://reviews.llvm.org/D58540

llvm-svn: 354769
2019-02-25 10:48:31 +00:00
Rui Ueyama c94dad9d97 Remove a function from header and move the implementation to a .cpp file. NFC.
llvm-svn: 354703
2019-02-22 23:59:43 +00:00
Peter Collingbourne f9232b0c00 ELF: Remove dead code. NFCI.
RelocationBaseSection is not used in -r links, so Config->Relocatable will
always be false.

Differential Revision: https://reviews.llvm.org/D58489

llvm-svn: 354607
2019-02-21 18:53:58 +00:00
Simon Atanasyan 14b09810a0 [mips] Put some MIPS-specific sections to separate segments
Three MIPS-specific sections `.reginfo`, `.MIPS.options`, and `.MIPS.abiflags`
are used by loader to read their contents and setup environment for running
a program. Loader looks up these data in the corresponding segments:
`PT_MIPS_REGINFO`, `PT_MIPS_OPTIONS`, and `PT_MIPS_ABIFLAGS` respectively.

This patch put these sections to separate segments like we do already
for ARM `SHT_ARM_EXIDX` section.

Differential Revision: http://reviews.llvm.org/D58381

llvm-svn: 354468
2019-02-20 14:47:02 +00:00
Fangrui Song eaa0db021f ELF: Remove field for .gdb_index in InStruct. NFC.
Summary: This field is unreferenced outside of createSyntheticSections.

Reviewers: ruiu, pcc, espindola, grimar

Reviewed By: grimar

Subscribers: grimar, emaste, arichardson, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58423

llvm-svn: 354449
2019-02-20 11:34:18 +00:00
Peter Collingbourne 7cca803d4c ELF: Remove field for .interp in InStruct. NFC.
This field is unreferenced outside of createSyntheticSections.

Differential Revision: https://reviews.llvm.org/D58422

llvm-svn: 354428
2019-02-20 02:32:53 +00:00
Tom Stellard 20332cc4ea ELF: Fix typo in --build-id option description
Reviewers: ruiu, espindola

Reviewed By: ruiu

Subscribers: emaste, arichardson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58265

llvm-svn: 354422
2019-02-20 01:40:35 +00:00
Rui Ueyama 3ae6726234 Sort enum members so that arch-dependent members are at the right place. NFC.
llvm-svn: 354405
2019-02-20 00:01:21 +00:00
Simon Atanasyan a6012a65d4 [mips] Create LA25 thunks for MIPS R6 code
MIPS R6 code uses the `R_MIPS_PC26_S2` relocation for calls which might
cross boundaries of non-PIC-to-PIC code. We need to create a LA25 thunks
for that case.

llvm-svn: 354312
2019-02-19 11:11:12 +00:00
Simon Atanasyan fae2a509fa [MIPS] Handle cross-mode (regular <-> microMIPS) jumps
The patch solves two tasks:

1. MIPS ABI allows to mix regular and microMIPS code and perform
cross-mode jumps. Linker needs to detect such cases and replace
jump/branch instructions by their cross-mode equivalents.

2. Other tools like dunamic linkers need to recognize cases when dynamic
table entries, e_entry field of an ELF header etc point to microMIPS
symbol. Linker should provide such information.

The first task is implemented in the `MIPS<ELFT>::relocateOne()` method.
New routine `fixupCrossModeJump` detects ISA mode change, checks and
replaces an instruction.

The main problem is how to recognize that relocation target is microMIPS
symbol. For absolute and section symbols compiler or assembler set the
less-significant bit of the symbol's value or sum of the symbol's value
and addend. And this bit signals to linker about microMIPS code. For
global symbols compiler cannot do the same trick because other tools like,
for example, disassembler wants to know an actual position of the symbol.
So compiler sets STO_MIPS_MICROMIPS flag in the `st_other` field.

In `MIPS<ELFT>::relocateOne()` method we have a symbol's value only and
cannot access any symbol's attributes. To pass type of the symbol
(regular/microMIPS) to that routine as well as other places where we
write a symbol value as-is (.dynamic section, `Elf_Ehdr::e_entry` field
etc) we set when necessary a less-significant bit in the `getSymVA`
function.

Differential revision: https://reviews.llvm.org/D40147

llvm-svn: 354311
2019-02-19 10:36:58 +00:00
Rui Ueyama 9efdd7ac5e [PPC64] Preserve LocalEntry when linking
On PowerPC64, it is necessary to keep the LocalEntry bits in st_other,
especially when -r is used. Otherwise, when the resulting object is used
in a posterior linking, LocalEntry info will be unavailable and
functions may be called through the wrong entrypoint.

Patch by Leandro Lupori.

Differential Revision: https://reviews.llvm.org/D56782

llvm-svn: 354184
2019-02-15 23:11:18 +00:00
Konstantin Zhuravlyov 87498153aa LLD/AMDGPU: Preserve ABI version during linking ELF for AMDGPU
Differential Revision: https://reviews.llvm.org/D58026

llvm-svn: 354086
2019-02-14 23:59:44 +00:00
Nick Desaulniers c3aefedc46 Revert "Revert "[lld] Fix elf::unlinkAsync detached thread""
This reverts commit 9934f2ff02dba9fdabe6e27a83f9f95388bf4132.

llvm-svn: 354081
2019-02-14 23:41:23 +00:00
Nick Desaulniers 289d70cf58 Revert "[lld] Fix elf::unlinkAsync detached thread"
This reverts commit 2694810153.

llvm-svn: 354080
2019-02-14 23:39:32 +00:00
Vitaly Buka 2694810153 [lld] Fix elf::unlinkAsync detached thread
Summary:
So this patch just make sure that the thread is at least stated
before we return from main.

If we just detach then the thread may be actually be stated just after
the process returned from main and it's calling atexit handers. Then the thread may try to create own function static variable and it will
add new at exit handlers confusing libc.

GLIBC before 2.27 had race in that case which corrupted atexit handlers
list. Support for this use-case for other implementation is also unclear,
so we can try just avoid that.

PR40162

Reviewers: ruiu, espindola

Subscribers: emaste, arichardson, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58246

llvm-svn: 354078
2019-02-14 23:29:28 +00:00
Rui Ueyama 72c3b1ed1d Move a function from .h to .cpp and use a shorter name. NFC.
llvm-svn: 354054
2019-02-14 19:33:26 +00:00
Rui Ueyama 980fb790c1 Remove a comparator from header and instead use lambdas for simplicity. NFC.
llvm-svn: 354052
2019-02-14 19:21:10 +00:00
Rui Ueyama f69bbbbdd2 Add a comment. NFC.
llvm-svn: 354049
2019-02-14 18:50:59 +00:00
Rui Ueyama b8b81e9b43 Improve error message for unknown relocations.
Previously, we showed the following message for an unknown relocation:

  foo.o: unrecognized reloc 256

This patch improves it so that the error message includes a symbol name:

  foo.o: unknown relocation (256) against symbol bar

llvm-svn: 354040
2019-02-14 18:02:20 +00:00
Peter Collingbourne 8331f61a51 ELF: Allow GOT relocs pointing to non-preemptable ifunc to resolve to an IRELATIVE where possible.
Non-GOT non-PLT relocations to non-preemptible ifuncs result in the
creation of a canonical PLT, which now takes the identity of the IFUNC
in the symbol table. This (a) ensures address consistency inside and
outside the module, and (b) fixes a bug where some of these relocations
end up pointing to the resolver.

Fixes (at least) PR40474 and PR40501.

Differential Revision: https://reviews.llvm.org/D57371

llvm-svn: 353981
2019-02-13 21:49:55 +00:00
Rui Ueyama 4134143cf5 Recover elf32-bigmips and elf32-powerpc support in LLD
This fixes a 7.0 -> 8.0 regression when parsing
OUTPUT_FORMAT("elf32-powerpc"); or elf32-bigmips directive in ldscripts
as well as an unknown emulation error when lld is invoked by clang due
to missed elf32ppclinux case.

Patch by vit9696

Differential Revision: https://reviews.llvm.org/D58005

llvm-svn: 353968
2019-02-13 18:51:15 +00:00
Rui Ueyama 265e8e8252 Show "Unknown -z option" error message even if --version or --help are given.
Previously, we validated -z options after we process --version or --help flags.
So, if one of these flags is given, we wouldn't show an "unknown -z option"
error. This patch fixes that behavior.

Differential Revision: https://reviews.llvm.org/D55446

llvm-svn: 353967
2019-02-13 18:48:39 +00:00
Sean Fertile d694160e66 [PPC64] Sort .toc sections accessed with small code model relocs.
A follow up to the intial patch that unblocked linking against libgcc.
For lld we don't need to bother tracking which objects have got based small
code model relocations. This is due to the fact that the compilers on
powerpc64 use the .toc section to generate indirections to symbols (rather then
using got relocations) which keeps the got small. This makes overflowing a
small code model got relocation very unlikely.

Differential Revision: https://reviews.llvm.org/D57245

llvm-svn: 353849
2019-02-12 15:35:49 +00:00
Rui Ueyama 016833bac2 lld: unquote possibly quoted `EXTERN("symbol")` entry in linker script.
gold accepts quoted strings. binutils requires quoted strings for some
kinds of symbols, e.g.:

  it accepts quoted symbols with @ in name:

  $ echo 'EXTERN("__libc_start_main@@GLIBC_2.2.5")' > a.script
  $ g++ a.script
  /usr/lib/gcc/x86_64-redhat-linux/4.8.5/../../../../lib64/crt1.o: In function `_start':
  (.text+0x20): undefined reference to `main'
  collect2: error: ld returned 1 exit status

  but rejects them if unquoted:

  $ echo 'EXTERN(__libc_start_main@@GLIBC_2.2.5)' > a.script
  $ g++ a.script
  a.script: file not recognized: File format not recognized
  collect2: error: ld returned 1 exit status

To maintain compatibility with existing linker scripts support quoted
strings in lld as well.

Patch by Lucian Adrian Grijincu.

Differential Revision: https://reviews.llvm.org/D57987

llvm-svn: 353756
2019-02-11 22:01:32 +00:00
Fangrui Song 283d103bde [ELF] Delete a comment that is no longer correct. Fix a typo. NFC
llvm-svn: 353605
2019-02-09 10:09:40 +00:00
Rui Ueyama 04cbd988f9 Fix a bug in R_X86_64_PC{8,16} relocation handling.
R_X86_64_PC{8,16} relocations are sign-extended, so when we check
for relocation overflow, we had to use checkInt instead of checkUInt.
I confirmed that GNU linkers create the same output for the test case.

llvm-svn: 353437
2019-02-07 18:12:57 +00:00
George Rimar 55f7c72bea [LLD][ELF] - Set DF_STATIC_TLS flag for X64 target
This is the same as D57749, but for x64 target.

"ELF Handling For Thread-Local Storage" p41 says (https://www.akkadia.org/drepper/tls.pdf):
R_X86_64_GOTTPOFF relocation is used for IE TLS models.
Hence if linker sees this relocation we should add DF_STATIC_TLS flag.

Differential revision: https://reviews.llvm.org/D57821

llvm-svn: 353378
2019-02-07 07:59:43 +00:00
Ed Maste e9932c103b Correct "varaible" typo in comment
llvm-svn: 353340
2019-02-06 20:36:02 +00:00
Rui Ueyama 1b11e9e8a4 Remove a small header that is used only by one file. NFC.
llvm-svn: 353331
2019-02-06 19:28:23 +00:00
Rui Ueyama 7c77044a38 Add comment.
llvm-svn: 353323
2019-02-06 18:53:17 +00:00
Rui Ueyama 33dbcbb2bc Support R_X86_64_PC8 and R_X86_64_PC16.
They are defined by the x86-64 ELF ABI standard.

Differential Revision: https://reviews.llvm.org/D57799

llvm-svn: 353314
2019-02-06 16:50:09 +00:00
George Rimar ae54e58b90 Recommit r353293 "[LLD][ELF] - Set DF_STATIC_TLS flag for i386 target."
With the following changes:
1) Compilation fix:
std::atomic<bool> HasStaticTlsModel = false; ->
std::atomic<bool> HasStaticTlsModel{false};

2) Adjusted the comment in code.

Initial commit message:

DF_STATIC_TLS flag indicates that the shared object or executable
contains code using a static thread-local storage scheme.

Patch checks if IE/LE relocations were used to check if the code uses
a static model. If so it sets the DF_STATIC_TLS flag.

Differential revision: https://reviews.llvm.org/D57749
----
Modified : /lld/trunk/ELF/Arch/X86.cpp
Modified : /lld/trunk/ELF/Config.h
Modified : /lld/trunk/ELF/SyntheticSections.cpp
Added : /lld/trunk/test/ELF/Inputs/i386-static-tls-model1.s
Added : /lld/trunk/test/ELF/Inputs/i386-static-tls-model2.s
Added : /lld/trunk/test/ELF/Inputs/i386-static-tls-model3.s
Added : /lld/trunk/test/ELF/Inputs/i386-static-tls-model4.s
Added : /lld/trunk/test/ELF/i386-static-tls-model.s
Modified : /lld/trunk/test/ELF/i386-tls-ie-shared.s
Modified : /lld/trunk/test/ELF/tls-dynamic-i686.s
Modified : /lld/trunk/test/ELF/tls-opt-iele-i686-nopic.s

llvm-svn: 353299
2019-02-06 14:43:30 +00:00
George Rimar 52fafcb919 Revert r353293 "[LLD][ELF] - Set DF_STATIC_TLS flag for i386 target."
It broke BB:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/43450
http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/27891

Error is:
tools/lld/ELF/Config.h:84:41: error: copying member subobject of type
'std::atomic<bool>' invokes deleted constructor std::atomic<bool> HasStaticTlsModel = false;

llvm-svn: 353297
2019-02-06 13:53:32 +00:00
George Rimar da60ad220b [LLD][ELF] - Set DF_STATIC_TLS flag for i386 target.
DF_STATIC_TLS flag indicates that the shared object or executable
contains code using a static thread-local storage scheme.

Patch checks if IE/LE relocations were used to check if the code uses
a static model. If so it sets the DF_STATIC_TLS flag.

Differential revision: https://reviews.llvm.org/D57749

llvm-svn: 353293
2019-02-06 13:38:10 +00:00
Fangrui Song f55e9a2d2e [PPC64] Set the number of relocations processed for R_PPC64_TLS[GL]D to 2
Summary:
R_PPC64_TLSGD and R_PPC64_TLSLD are used as markers on TLS code sequences. After GD-to-IE or GD-to-LE relaxation, the next relocation R_PPC64_REL24 should be skipped to not create a false dependency on __tls_get_addr. When linking statically, the false dependency may cause an "undefined symbol: __tls_get_addr" error.

R_PPC64_GOT_TLSGD16_HA
R_PPC64_GOT_TLSGD16_LO
R_PPC64_TLSGD R_TLSDESC_CALL
R_PPC64_REL24 __tls_get_addr

Reviewers: ruiu, sfertile, syzaara, espindola

Reviewed By: sfertile

Subscribers: emaste, nemanjai, arichardson, kbarton, jsji, llvm-commits, tamur

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57673

llvm-svn: 353262
2019-02-06 02:00:24 +00:00
Rui Ueyama 3fdb07258b Inline a trivial function and update comment. NFC.
llvm-svn: 353200
2019-02-05 19:19:45 +00:00
Fangrui Song ae0294375f [ELF] Default to --no-allow-shlib-undefined for executables
Summary:
This follows the ld.bfd/gold behavior.

The error check is useful as it captures a common type of ld.so undefined symbol errors as link-time errors:

    // a.cc => a.so (not linked with -z defs)
    void f(); // f is undefined
    void g() { f(); }

    // b.cc => executable with a DT_NEEDED entry on a.so
    void g();
    int main() { g(); }

    // ld.so errors when g() is executed (lazy binding) or when the program is started (-z now)
    // symbol lookup error: ... undefined symbol: f

Reviewers: ruiu, grimar, pcc, espindola

Reviewed By: ruiu

Subscribers: llvm-commits, emaste, arichardson

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57569

llvm-svn: 352943
2019-02-02 00:34:28 +00:00
Fangrui Song b4744d306c [ELF] Support --{,no-}allow-shlib-undefined
Summary:
In ld.bfd/gold, --no-allow-shlib-undefined is the default when linking
an executable. This patch implements a check to error on undefined
symbols in a shared object, if all of its DT_NEEDED entries are seen.

Our approach resembles the one used in gold, achieves a good balance to
be useful but not too smart (ld.bfd traces all DSOs and emulates the
behavior of a dynamic linker to catch more cases).

The error is issued based on the symbol table, different from undefined
reference errors issued for relocations. It is most effective when there
are DSOs that were not linked with -z defs (e.g. when static sanitizers
runtime is used).

gold has a comment that some system libraries on GNU/Linux may have
spurious undefined references and thus system libraries should be
excluded (https://sourceware.org/bugzilla/show_bug.cgi?id=6811). The
story may have changed now but we make --allow-shlib-undefined the
default for now. Its interaction with -shared can be discussed in the
future.

Reviewers: ruiu, grimar, pcc, espindola

Reviewed By: ruiu

Subscribers: joerg, emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D57385

llvm-svn: 352826
2019-02-01 02:25:05 +00:00
Sam Clegg dfbd19033b Fix names of functions in TargetOptionsCommandFlags.h. NFC.
Differential Revision: https://reviews.llvm.org/D57555

llvm-svn: 352825
2019-02-01 02:24:50 +00:00
Sam Clegg 5cdc91d003 [LTO] Set CGOptLevel in LTO config.
Previously we were never setting this which means it was always being
set to Default (-O2/-Os).

Differential Revision: https://reviews.llvm.org/D57422

llvm-svn: 352667
2019-01-30 20:46:18 +00:00
Dimitry Andric 19b134cc44 Recognize FreeBSD specific BFD names in OUTPUT_FORMAT
Summary:
After rLLD344952 ("Add OUTPUT_FORMAT linker script directive support"),
using BFD names such as `elf64-x86-64-freebsd` the `OUTPUT_FORMAT`
linker script command does not work anymore, resulting in errors like:

```
ld: error: /home/dim/src/clang800-import/stand/efi/loader/arch/amd64/ldscript.amd64:2: unknown output format name: elf64-x86-64-freebsd
>>> OUTPUT_FORMAT("elf64-x86-64-freebsd", "elf64-x86-64-freebsd", "elf64-x86-64-freebsd")
>>>               ^
```

To fix this, recognize a `-freebsd` suffix in BFD names, and also set
`Configuration::OSABI` to `ELFOSABI_FREEBSD` for those cases.

Add and/or update several test cases to check for the correct results of
these new `OUTPUT_FORMAT` arguments.

Reviewers: ruiu, atanasyan, grimar, hokein, emaste, espindola

Reviewed By: ruiu

Subscribers: nemanjai, javed.absar, arichardson, krytarowski, kristof.beyls, kbarton, llvm-commits

Differential Revision: https://reviews.llvm.org/D57283

llvm-svn: 352606
2019-01-30 06:31:52 +00:00
Fangrui Song ae82599a30 [ELF] Simplify. NFC
llvm-svn: 352499
2019-01-29 14:24:35 +00:00
George Rimar ff193c473e [ELF] - Remove dead `readBfdName` declaration. NFC.
`readBfdName` was removed recently.

llvm-svn: 352482
2019-01-29 11:46:00 +00:00
Rui Ueyama 0068d223ee Attempt to fix build failure with GCC 5.4.
llvm-svn: 352435
2019-01-28 21:45:50 +00:00
Peter Collingbourne ff35dbac47 ELF: Set sh_info on RelaIplt to point to the IgotPlt output section.
Previously we were setting it to the GotPlt output section, which is
incorrect on ARM where this section is in .got. In static binaries
this can lead to sh_info being set to -1 (because there is no .got.plt)
which results in various tools rejecting the output file.

Differential Revision: https://reviews.llvm.org/D57274

llvm-svn: 352413
2019-01-28 19:29:41 +00:00
Rui Ueyama 4f8c82281d Refactoring. NFC.
llvm-svn: 352407
2019-01-28 19:11:52 +00:00
Nick Desaulniers 6cff0cb35a lld: elf: discard more specific .gnu.linkonce section
Summary:
lld discards .gnu.linonce.* sections work around a bug in glibc.
https://sourceware.org/bugzilla/show_bug.cgi?id=20543

Unfortunately, the Linux kernel uses a section named
.gnu.linkonce.this_module to store infomation about kernel modules. The
kernel reads data from this section when loading kernel modules, and
errors if it fails to find this section. The current behavior of lld
discards this section when kernel modules are linked, so kernel modules
linked with lld are unloadable by the linux kernel.

The Linux kernel should use a comdat section instead of .gnu.linkonce.
The minimum version of binutils supported by the kernel supports comdat
sections. The kernel is also not relying on the old linkonce behavior;
it seems to have chosen a name that contains a deprecated GNU feature.

Changing the section name now in the kernel would require all kernel
modules to be recompiled to make use of the new section name. Instead,
rather than discarding .gnu.linkonce.*, let's discard the more specific
section name to continue working around the glibc issue while supporting
linking Linux kernel modules.

Link: https://github.com/ClangBuiltLinux/linux/issues/329

Reviewers: pcc, espindola

Reviewed By: pcc

Subscribers: nathanchance, emaste, arichardson, void, srhines

Differential Revision: https://reviews.llvm.org/D57294

llvm-svn: 352302
2019-01-27 02:54:23 +00:00
Rui Ueyama 3749befe74 Remove dead declaration.
llvm-svn: 352257
2019-01-26 00:31:49 +00:00
Rui Ueyama e14e46b3f1 Simplify. NFC.
llvm-svn: 352242
2019-01-25 21:25:25 +00:00
Sean Fertile 83cb252876 [PPC64] Reland r351978 'Sort .toc sections accessed with small code model ...'
Guessing that the slashes used in the scripts SECTION command was causing the
windows related failures in the added test.

Original commit message:
Small code model global variable access on PPC64 has a very limited range of
addressing. The instructions the relocations are used on add an offset in the
range [-0x8000, 0x7FFC] to the toc pointer which points to .got +0x8000, giving
an addressable range of [.got, .got + 0xFFFC]. While user code can be recompiled
with medium and large code models when the binary grows too large for small code
model, there are small code model relocations in the crt files and libgcc.a
which are typically shipped with the distros, and the ABI dictates that linkers
must allow linking of relocatable object files using different code models.

To minimze the chance of relocation overflow, any file that contains a small
code model relocation should have its .toc section placed closer to the .got
then any .toc from a file without small code model relocations.

Differential Revision: https://reviews.llvm.org/D56920

llvm-svn: 352071
2019-01-24 18:17:40 +00:00
Rui Ueyama ec33fd6dd5 Untabify.
llvm-svn: 352070
2019-01-24 18:17:17 +00:00
Serge Guelton 1fa239f500 Partial support of SHT_GROUP without flag
This does *not* implement full SHT_GROUP semantic, yet it is a simple step forward:
Sections within a group are still considered valid, but they do not behave as
specified by the standard in case of garbage collection.

Differential Revision: https://reviews.llvm.org/D56437

llvm-svn: 352068
2019-01-24 17:56:08 +00:00
Sean Fertile 72679cff12 Revert "[PPC64] Sort .toc sections accessed with small code model ..."
This reverts commit ca87c57a3aa4770c9cf0defd4b2feccbc342ee93.
Added test fails on several windows buildbots.

llvm-svn: 351985
2019-01-23 21:46:28 +00:00
Sean Fertile a010cf615a [PPC64] Sort .toc sections accessed with small code model relocs close to .got.
Small code model global variable access on PPC64 has a very limited range of
addressing. The instructions the relocations are used on add an offset in the
range [-0x8000, 0x7FFC] to the toc pointer which points to .got +0x8000, giving
an addressable range of [.got, .got + 0xFFFC]. While user code can be recompiled
with medium and large code models when the binary grows too large for small code
model, there are small code model relocations in the crt files and libgcc.a
which are typically shipped with the distros, and the ABI dictates that linkers
must allow linking of relocatable object files using different code models.

To minimze the chance of relocation overflow, any file that contains a small
code model relocation should have its .toc section placed closer to the .got
then any .toc from a file without small code model relocations.

Differential Revision: https://reviews.llvm.org/D56920

llvm-svn: 351978
2019-01-23 21:04:03 +00:00
Peter Collingbourne bcd08c16bb COFF, ELF: ICF: Perform 2 rounds of relocation hash propagation.
LLD's performance on PGO instrumented Windows binaries was still not
great even with the fix in D56955; out of the 2m41s linker runtime,
around 2 minutes were still being spent in ICF. I looked into this more
closely and discovered that the vast majority of the runtime was being
spent segregating .pdata sections with the following relocation chain:

.pdata -> identical .text -> unique PGO counter (not eligible for ICF)

This patch causes us to perform 2 rounds of relocation hash
propagation, which allows the hash for the .pdata sections to
incorporate the identifier from the PGO counter. With that, the amount
of time spent in ICF was reduced to about 2 seconds. I also found that
the same change led to a significant ICF performance improvement in a
regular release build of Chromium's chrome_child.dll, where ICF time
was reduced from around 1s to around 700ms.

With the same change applied to the ELF linker, median of 100 runs
for lld-speed-test/chrome reduced from 4.53s to 4.45s on my machine.

I also experimented with increasing the number of propagation rounds
further, but I did not observe any further significant performance
improvements linking Chromium or Firefox.

Differential Revision: https://reviews.llvm.org/D56986

llvm-svn: 351899
2019-01-22 23:54:49 +00:00
Peter Collingbourne 3426111145 COFF, ELF: Adjust ICF hash computation to account for self relocations.
It turns out that sections in PGO instrumented object files on Windows
contain a large number of relocations pointing to themselves. With
r347429 this can cause many sections to receive the same hash (usually
zero) as a result of a section's hash being xor'ed with itself.

This patch causes the COFF and ELF linkers to avoid this problem
by adding the hash of the relocated section instead of xor'ing it.
On my machine this causes the regressing test case
provided by Mozilla to terminate in 2m41s.

Differential Revision: https://reviews.llvm.org/D56955

llvm-svn: 351898
2019-01-22 23:51:35 +00:00