Commit Graph

1254 Commits

Author SHA1 Message Date
Pavel Labath 47c3472c41 [DebugInfo/AccelTable] Fix inconsistency in getDIEOffset implementations
Summary:
Even though the getDIEOffset offset function was common for the two
accelerator table implementations, it was doing two different things:
for the Apple tables, it was returning the die offset relative to the
start of the section, whereas for DWARF v5 tables, it was relative to
the start of the CU.

I resolve this by renaming the function to getDIESectionOffset to make
it obvious what the function returns, and change the DWARF
implementation to return the section offset. I also keep the CU-relative
accessor, but only in the DWARF implementation (there is no way to get
this information for the Apple tables). This was not caught by existing
tests because the hand-written inputs also erroneously used section
offsets instead of CU-relative ones.

While looking at this, I noticed that the Apple implementation was not
fully correct either -- the header contains a DIEOffsetBase field, which
should be added to offsets encoded with the DW_FORM_ref*** family, but
this was not being used. This went unnoticed because all current writers
set this field to zero anyway. I fix this as well and add a hand-written
test which demonstrates the issue.

Reviewers: JDevlieghere, dblaikie

Subscribers: aprantl, llvm-commits

Differential Revision: https://reviews.llvm.org/D44202

llvm-svn: 327116
2018-03-09 11:58:59 +00:00
Jonas Devlieghere 6921753994 [Support] Move syntax highlighting into support
Move the DWARF syntax highlighting into support. This has several
advantages, most notably that this makes the WithColor RAII wrapper
available outside libDebugInfo. Furthermore, several projects all have
their own code for handling colored output. This provides a place to
centralize it.

Differential revision: https://reviews.llvm.org/D44215

llvm-svn: 327108
2018-03-09 09:56:24 +00:00
Benjamin Kramer 70e6faaa0d [DebugInfo] Move RangeListEntries instead of copying.
This is needed for correctness as RangeListEntry is not copy-assignable,
which std::vector might rely on.

llvm-svn: 327067
2018-03-08 21:31:10 +00:00
Zachary Turner 145bc6e0d3 Fix compilation failure with MSVC.
llvm-svn: 327063
2018-03-08 21:07:30 +00:00
Wolfgang Pieb a0729d4126 [DWARF v5] Support for verbose dumping of .debug_rnglist entries
Adding verbose dumping to the recent implementation of dumping of v5 range list entries. 
We're capturing the entries as is as they come in during extraction, including their file offset,
so we can dump them in more detail.
The offset table entries which are table-relative are shown as is (as in non-verbose mode)
and with the actual file offset they map to.

Reviewers: dblaikie, aprantl, jdevlieghere, jhenderson

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43366

llvm-svn: 327059
2018-03-08 20:52:35 +00:00
Pavel Labath b136c3934e DWARFVerifier: Basic verification of .debug_names
Summary:
This patch adds basic .debug_names verification capabilities to the
DWARF verifier. Right now, it checks that the headers and abbreviation
tables of the individual name indexes can be parsed correctly, it
verifies the buckets table and the cross-checks the CU lists for
consistency. I intend to add further checks in follow-up patches.

Reviewers: JDevlieghere, aprantl, probinson, dblaikie

Subscribers: vleschuk, echristo, clayborg, llvm-commits

Differential Revision: https://reviews.llvm.org/D44211

llvm-svn: 327011
2018-03-08 15:34:42 +00:00
James Henderson 667026297d [DWARF] Don't attempt to parse line tables at invalid offsets
Whilst working on improvements to the error handling of the debug line
parsing code, I noticed that if an invalid offset were to be specified
in a call to getOrParseLineTable(), an entry in the LineTableMap would
still be created, even if the offset was not within the section range.
The immediate parsing attempt afterwards would fail (it would end up
getting a version of 0), and thereafter, any subsequent calls to
getOrParseLineTable or getLineTable would return the default-
constructed, invalid line table. In reality, we shouldn't even attempt
to parse this table, and we should always return a nullptr from these
two functions for this situation.

I have tested this via a unit test, which required some new framework
for unit testing debug line. My plan is to add quite a few more unit
tests for the new error reporting mechanism that will follow shortly,
hence the reason why the supporting code for the tests are written the
way they are - I intend to extend the DwarfGenerator class to support
generating debug line. At that point, I'll make sure that there are a
few positive test cases for this and the parsing code too.

Differential Revision: https://reviews.llvm.org/D44200

Reviewers: JDevlieghere, aprantl
llvm-svn: 326995
2018-03-08 10:53:34 +00:00
Rafael Auler 86fb7bf2bc Reland "[DebugInfo] Support DWARF expressions in eh_frame"
Summary:
Original change was D43313 (r326932) and reverted by r326953 because it
broke an LLD test and a windows build. The LLD test was already fixed in
lld commit r326944 (thanks maskray). This is the original change with
the windows build fixed.

llvm-svn: 326970
2018-03-08 00:46:53 +00:00
Eugene Zemtsov c4a13015fd Fix build broken by r326959
Adding Demangle to link time dependencies of Symbolize

llvm-svn: 326964
2018-03-08 00:07:26 +00:00
Eugene Zemtsov cd72cbc667 Use itaniumDemangle in llvm-symbolizer
Currently on Windows (_MSC_VER) LLVMSymbolizer supports only Microsoft mangling.
This fix just explicitly uses itaniumDemangle when mangled name starts with _Z.

Differential Revision: https://reviews.llvm.org/D44192

llvm-svn: 326959
2018-03-07 23:07:34 +00:00
Rui Ueyama 6aa8b3491f Revert r326932: [DebugInfo] Support DWARF expressions in eh_frame
This reverts commit rr326932 because it broke lld/test/ELF/eh-frame-hdr-augmentation.s.

llvm-svn: 326953
2018-03-07 22:29:48 +00:00
Rafael Auler 7fdf44440c [DebugInfo] Support DWARF expressions in eh_frame
This patch enhances DWARFDebugFrame with the capability of parsing and
printing DWARF expressions in CFI instructions. It also makes FDEs and
CIEs accessible to lib users, so they can process them in client tools
that rely on LLVM. To make it self-contained with a test case, it
teaches llvm-readobj to be able to dump EH frames and checks they are
correct in a unit test. The llvm-readobj code is Maksim Panchenko's work
(maksfb).

Reviewers: JDevlieghere, espindola

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D43313

llvm-svn: 326932
2018-03-07 19:19:51 +00:00
Jonas Devlieghere bf8596f9cf [dwarfdump] Only print CU relative offset in verbose mode
Instead of only printing the CU-relative offset in non-verbose mode, it
makes more sense to only printed the resolved address. In verbose mode
we still print both.

Differential revision: https://reviews.llvm.org/D44148

rdar://33525475

llvm-svn: 326903
2018-03-07 16:28:53 +00:00
Aaron Smith 25409ddf2a [DebugInfoPDB] Add DIA implementation for getSrcLineOnTypeDefn
Summary: This helps to determine the line number for a PDB type with definition

Reviewers: zturner, llvm-commits, rnk

Reviewed By: zturner

Subscribers: rengolin, JDevlieghere

Differential Revision: https://reviews.llvm.org/D44119

llvm-svn: 326857
2018-03-07 00:33:09 +00:00
Francis Ricci fe6cbceec2 [llvm-symbolizer] Use correct path when resolving .gnu_debuglink in .debug
Summary:
The symbolizer was checking for .debug as a subdirectory of the
binary file itself, not of the directory containing the binary. This led to
a failure to find split debug info when it was contained in a .debug directory.

Reviewers: rnk, glider, zturner

Subscribers: llvm-commits, aprantl

Differential Revision: https://reviews.llvm.org/D44025

llvm-svn: 326630
2018-03-02 22:56:45 +00:00
Zachary Turner c6a75a69f1 [PDB] Defer writing the build id until the rest of the PDB is written.
For now this is NFC, but this small refactor opens the door to
letting us embed a hash of the PDB in the build id field of the
PDB.

Differential Revision: https://reviews.llvm.org/D43913

llvm-svn: 326453
2018-03-01 18:00:29 +00:00
Reid Kleckner 3acdc67734 [CodeView] Lower __restrict and other pointer qualifiers correctly
Qualifiers on a pointer or reference type may apply to either the
pointee or the pointer itself. Consider 'const char *' and 'char *
const'. In the first example, the pointee data may not be modified
without casts, and in the second example, the pointer may not be updated
to point to new data.

In the general case, qualifiers are applied to types with LF_MODIFIER
records, which support the usual const and volatile qualifiers as well
as the __unaligned extension qualifier.

However, LF_POINTER records, which are used for pointers, references,
and member pointers, have flags for qualifiers applying to the
*pointer*. In fact, this is the only way to represent the restrict
qualifier, which can only apply to pointers, and cannot qualify regular
data types.

This patch causes LLVM to correctly fold 'const' and 'volatile' pointer
qualifiers into the pointer record, as well as adding support for
'__restrict' qualifiers in the same place.

Based on a patch from Aaron Smith

Differential Revision: https://reviews.llvm.org/D43060

llvm-svn: 326260
2018-02-27 22:08:15 +00:00
Reid Kleckner 22d838cd31 [codeview] Remove unused variable
llvm-svn: 326253
2018-02-27 21:46:40 +00:00
Pavel Labath d99072bc97 Implement equal_range for the DWARF v5 accelerator table
Summary:
This patch implements the name lookup functionality of the .debug_names
accelerator table and hooks it up to "llvm-dwarfdump -find". To make the
interface of the two kinds of accelerator tables more consistent, I've
created an abstract "DWARFAcceleratorTable::Entry" class, which provides
a consistent interface to access the common functionality of the table
entries (such as getting the die offset, die tag, etc.). I've also
modified the apple table to vend entries conforming to this interface.

Reviewers: JDevlieghere, aprantl, probinson, dblaikie

Subscribers: vleschuk, clayborg, echristo, llvm-commits

Differential Revision: https://reviews.llvm.org/D43067

llvm-svn: 326003
2018-02-24 00:35:21 +00:00
Scott Linder 16c7bdaf32 [DebugInfo] Support DWARF v5 source code embedding extension
In DWARF v5 the Line Number Program Header is extensible, allowing values with
new content types. In this extension a content type is added,
DW_LNCT_LLVM_source, which contains the embedded source code of the file.

Add new optional attribute for !DIFile IR metadata called source which contains
source text. Use this to output the source to the DWARF line table of code
objects. Analogously extend METADATA_FILE in Bitcode and .file directive in ASM
to support optional source.

Teach llvm-dwarfdump and llvm-objdump about the new values. Update the output
format of llvm-dwarfdump to make room for the new attribute on file_names
entries, and support embedded sources for the -source option in llvm-objdump.

Differential Revision: https://reviews.llvm.org/D42765

llvm-svn: 325970
2018-02-23 23:01:06 +00:00
Aaron Smith 89a19ac38d [PDB] Check the result of setLoadAddress()
Summary: Change setLoadAddress() to return true or false on failure.

Reviewers: zturner, llvm-commits

Reviewed By: zturner

Differential Revision: https://reviews.llvm.org/D43638

llvm-svn: 325843
2018-02-23 00:02:27 +00:00
Aaron Smith 9161a6cb25 [PDB] Fix buildbot failure from missing include for DIAEnumLineNumbers
llvm-svn: 325826
2018-02-22 20:00:07 +00:00
Aaron Smith fbe65404fd [PDB] Implement more find methods for PDB symbols
Summary:
Add additional find methods on PDB raw symbols.

findChildrenByAddr()
findChildrenByVA()
findInlineFramesByAddr()
findInlineFramesByVA()
findInlineLines()
findInlineLinesByAddr()
findInlineLinesByRVA()
findInlineLinesByVA()




Reviewers: zturner, llvm-commits

Reviewed By: zturner

Differential Revision: https://reviews.llvm.org/D43637

llvm-svn: 325824
2018-02-22 19:47:43 +00:00
Jonas Devlieghere 7d4a974d8b [dwarfdump] Fix spurious verification errors for DW_AT_location attributes
Verifying any DWARF file that is optimized and contains at least one tag
with a DW_AT_location with a location list offset as a
DW_AT_form_dataXXX results in dwarfdump spuriously claiming that the
location list is invalid.

Differential revision: https://reviews.llvm.org/D40199

llvm-svn: 325430
2018-02-17 13:06:37 +00:00
Zachary Turner cafd476836 Fix emission of PDB string table.
This was originally reported as a bug with the symptom being "cvdump
crashes when printing an LLD-linked PDB that has an S_FILESTATIC record
in it". After some additional investigation, I determined that this was
a symptom of a larger problem, and in fact the real problem was in the
way we emitted the global PDB string table. As evidence of this, you can
take any lld-generated PDB, run cvdump -stringtable on it, and it would
return no results.

My hypothesis was that cvdump could not *find* the string table to begin
with. Normally it would do this by looking in the "named stream map",
finding the string /names, and using its value as the stream index. If
this lookup fails, then cvdump would fail to load the string table.

To test this hypothesis, I looked at the name stream map generated by a
link.exe PDB, and I emitted exactly those bytes into an LLD-generated
PDB. Suddenly, cvdump could read our string table!

This code has always been hacky and we knew there was something we
didn't understand. After all, there were some comments to the effect of
"we have to emit strings in a specific order, otherwise things don't
work". The key to fixing this was finally understanding this.

The way it works is that it makes use of a generic serializable hash map
that maps integers to other integers. In this case, the "key" is the
offset into a buffer, and the value is the stream number. If you index
into the buffer at the offset specified by a given key, you find the
name. The underlying cause of all these problems is that we were using
the identity function for the hash. i.e. if a string's offset in the
buffer was 12, the hash value was 12. Instead, we need to hash the
string *at that offset*. There is an additional catch, in that we have
to compute the hash as a uint32 and then truncate it to uint16.

Making this work is a little bit annoying, because we use the same hash
table in other places as well, and normally just using the identity
function for the hash function is actually what's desired. I'm not
totally happy with the template goo I came up with, but it works in any
case.

The reason we never found this bug through our own testing is because we
were building a /parallel/ hash table (in the form of an
llvm::StringMap<>) and doing all of our lookups and "real" hash table
work against that. I deleted all of that code and now everything goes
through the real hash table. Then, to test it, I added a unit test which
adds 7 strings and queries the associated values. I test every possible
insertion order permutation of these 7 strings, to verify that it really
does work as expected.

Differential Revision: https://reviews.llvm.org/D43326

llvm-svn: 325386
2018-02-16 20:46:04 +00:00
David Blaikie 3b6de6fe1c Revert "Rewrite the cached map used for locating the most precise DIE among inlined subroutines for a given address."
Seeing some inlining missing in internal uses of symbolizer. I'll work
on a reproduction, tests, improvements & recommit as soon as possible.

(Chandler would like it to be known that this improvement did make
check-llvm 4x faster... - so there's certainly some fairly good
motivation to push on fixing/figuring this out & getting it back in)

This reverts commit r321345.

llvm-svn: 324981
2018-02-13 01:52:30 +00:00
Adrian Prantl a5eee4de07 Simplify switch statement (NFC)
llvm-svn: 324945
2018-02-12 22:09:57 +00:00
Adrian Prantl 520789e139 Fix the syntax highlighting of strings in dwarfdump.
llvm-svn: 324936
2018-02-12 21:11:23 +00:00
Adrian Prantl baf9c20b02 Factor out common condition into an easier to understand helper function (NFC).
llvm-svn: 324935
2018-02-12 21:11:14 +00:00
Paul Robinson ceafcd41cf [DWARFv5] Fix dumper to show the file table starts at index 0.
Emitting the correct (root of compilation) file at index 0 will be
posted for review later; I wanted to get this minor change out of the
way first.

llvm-svn: 324669
2018-02-08 23:08:02 +00:00
Paul Robinson 0a22709f06 [DWARF] Regularize dumping strings from line tables.
The major visible difference here is that in line-table dumps,
directory and file names are wrapped in double-quotes; previously,
directory names got single quotes and file names were not quoted at
all.

The improvement in this patch is that when a DWARF v5 line table
header has indirect strings, in a verbose dump these will all have
their section[offset] printed as well as the name itself.  This
matches the format used for dumping strings in the .debug_info
section.

Differential Revision: https://reviews.llvm.org/D42802

llvm-svn: 324270
2018-02-05 20:43:15 +00:00
James Henderson 10392cdbf7 Fix more print format specifiers in debug_rnglists dumping
See also r324096.

I have made the assumption that DWARF64 is not an issue for the time
being with these fixes.

llvm-svn: 324223
2018-02-05 10:47:13 +00:00
Simon Pilgrim 3d5ee7aa41 Fix MSVC signed/unsigned comparison warning. NFCI.
llvm-svn: 324171
2018-02-03 12:38:56 +00:00
James Henderson 2465633234 Fix type sizes that were causing incorrect string formatting
llvm-svn: 324096
2018-02-02 15:09:31 +00:00
James Henderson c2dfd502a2 Add missing new files from r324077
Differential Revision: https://reviews.llvm.org/D42481

llvm-svn: 324078
2018-02-02 12:45:57 +00:00
James Henderson 3fcc74500a [DWARF v5] Add limited support for dumping .debug_rnglists
This change adds support to llvm-dwarfdump for dumping DWARF5
.debug_rnglists sections in regular ELF files.

It is not complete, in that several DW_RLE_* encodings are currently
not supported, but does dump the headert and the basic ranges for
DW_RLE_start_length and DW_RLE_start_end encodings.

Obvious next steps are to add verbose dumping that dumps the raw
encodings, rather than the interpreted contents, to add -verify support
of the section (e.g. to show that the correct number of offsets are
specified), add dumping of .debug_rnglists.dwo, and to add support for
other encodings.

Reviewed by: dblaikie, JDevlieghere

Differential Revision: https://reviews.llvm.org/D42481

llvm-svn: 324077
2018-02-02 12:35:52 +00:00
Zachary Turner 07d803777c [CodeView] Micro-optimizations to speed up type merging.
Based on a profile, a couple of hot spots were identified in the
main type merging loop.  The code was simplified, a few loops
were re-arranged, and some outlined functions were inlined.  This
speeds up type merging by a decent amount, shaving around 3-4 seconds
off of a 40 second link in my test case.

Differential Revision: https://reviews.llvm.org/D42559

llvm-svn: 323790
2018-01-30 17:12:04 +00:00
Paul Robinson d0c89f851b Stop tracking .debug_line_str in DWARFUnit. NFC.
llvm-svn: 323701
2018-01-29 22:02:56 +00:00
Paul Robinson bf750c80e9 [DWARFv5] Re-enable dumping a line table with no CU.
r323476 added support for DW_FORM_line_strp, and incorrectly made that
depend on having a DWARFUnit available.  We shouldn't be tracking
.debug_line_str in DWARFUnit after all.  After this patch, I can do an
NFC follow up and undo a bunch of the "plumbing" part of r323476.

Differential Revision: https://reviews.llvm.org/D42609

llvm-svn: 323691
2018-01-29 20:57:43 +00:00
Pavel Labath e7264106d4 Fix windows test failure caused by r323638
The test was failing because of an incorrect sizeof check in the name
index parsing code. This code was meant to check that we have enough
input to parse the fixed-size part of the dwarf header, which it did by
comparing the input to sizeof(Header). Originally struct Header only
contained the fixed-size part, but during review, we've moved additional
members into it, which rendered the sizeof check invalid.

I resolve this by moving the fixed-size part to a separate struct and
updating the sizeof-expression to use that.

llvm-svn: 323648
2018-01-29 13:53:48 +00:00
Pavel Labath 3460957ea3 Fix build broken by r323641
The call to ScopedPrinter::printNumber with size_t argument was
ambiguous (I think) on 32-bit builds. Explicitly cast to a 64-bit int to
avoid this.

llvm-svn: 323642
2018-01-29 11:53:46 +00:00
Pavel Labath 394e805668 Refactor dwarfdump -apple-names output
Summary:
This modifies the dwarfdump output to align it with the new .debug_names
dump. It also renames two header fields to match similar fields in the
dwarf5 header.

A couple of tests needed to be updated to match new output. The changes
were fairly straight-forward, although not really automatable.

Reviewers: JDevlieghere, aprantl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42415

llvm-svn: 323641
2018-01-29 11:33:17 +00:00
Pavel Labath 3c9a918c9e [DebugInfo] Basic .debug_names dumping support
Summary:
This commit renames DWARFAcceleratorTable to AppleAcceleratorTable to free up
the first name as an interface for the different accelerator tables.
Then I add a DWARFDebugNames class for the dwarf5 table.

Presently, the only common functionality of the two classes is the dump()
method, because this is the only method that was necessary to implement
dwarfdump -debug-names; and because the rest of the
AppleAcceleratorTable interface does not directly transfer to the dwarf5
tables (the main reason for that is that the present interface assumes
the tables are homogeneous, but the dwarf5 tables can have different
keys associated with each entry).

I expect to make the common interface richer as I add more functionality
to the new class (and invent a way to represent it in generic way).

In terms of sharing the implementation, I found the format of the two
tables sufficiently different to frustrate any attempts to have common
parsing or dumping code, so presently the implementations share just low
level code for formatting dwarf constants.

Reviewers: vleschuk, JDevlieghere, clayborg, aprantl, probinson, echristo, dblaikie

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42297

llvm-svn: 323638
2018-01-29 11:08:32 +00:00
Jonas Devlieghere 92ac9d3e1b [Support] Move DJB hash to support. NFC
This patch moves the DJB hash to support. This is consistent with other
hashing algorithms living there. The hash is used by the DWARF
accelerator tables. We're doing this now because the hashing function is
needed by dsymutil and we don't want to link against libBinaryFormat.

Differential revision: https://reviews.llvm.org/D42594

llvm-svn: 323616
2018-01-28 11:05:10 +00:00
Paul Robinson 0115844c2f [DWARFv5] Classify all the new forms. NFC.
Move standard forms from a switch statement to the table of forms;
fill in all the missing ones defined in DWARF v5.  I'm guessing at
classifications in a couple of cases where v5 forms aren't actually
supported yet, but whoever adds support for the forms can fix the
classifications as needed.

llvm-svn: 323481
2018-01-25 23:06:36 +00:00
Paul Robinson b6aa01ca99 [DWARFv5] Support DW_FORM_line_strp in llvm-dwarfdump.
This form is like DW_FORM_strp, but points to .debug_line_str instead
of .debug_str as the string section.  It's intended to be used from
the line-table header, and allows string-pooling of directory and
filenames across compilation units.

Differential Revision: https://reviews.llvm.org/D42553

llvm-svn: 323476
2018-01-25 22:02:36 +00:00
Pavel Labath 9b36fd2541 Rename DwarfAcceleratorTable to AppleAcceleratorTable. NFC
This frees up the first name to be used as an base class for the
apple table and the dwarf5 .debug_names accel table. The rename  was
split off from D42297 (adding of debug_names support), which is still
under review.

llvm-svn: 323113
2018-01-22 13:17:23 +00:00
Paul Robinson 8181d23b3d [DWARFv5] Number the line-table's directory array correctly.
The compilation directory has always been #0, but as of DWARF v5 it is
explicitly listed in the line-table section instead of implicitly
being a reference to the compile_unit DIE's DW_AT_comp_dir attribute.
This means the dumper should number the dumped array starting with 0
or 1 depending on the DWARF version of the line table.

References in the generated DWARF are correct, it's just the dumper
that was wrong.  Also some assembler-coded tests were similarly
confused about directory numbers.

llvm-svn: 322884
2018-01-18 20:33:35 +00:00
Zachary Turner 1bc2ce6b9b Speed up iteration of CodeView record streams.
There's some abstraction overhead in the underlying
mechanisms that were being used, and it was leading to an
abundance of small but not-free copies being made.  This
showed up on a profile.  Eliminating this and going back to
a low-level byte-based implementation speeds up lld with
/DEBUG between 10 and 15%.

Differential Revision: https://reviews.llvm.org/D42148

llvm-svn: 322871
2018-01-18 18:35:01 +00:00
Aaron Smith 53a1a1616c Fix pretty printing the unspecified param of a variadic function
Summary:
 - Fix a bug in PrettyBuiltinDumper that returns "void" as the name for
  an unspecified builtin type. Since the unspecified param of a variadic
  function is considered a builtin of unspecified type in PDBs, we set
  "..." for its name.

  - Provide a method to determine if a PDBSymbolFunc is variadic in
  PrettyFunctionDumper since PDBSymbolFunc::getArgument() doesn't return the
  last unspecified-type param.

  - Add a pretty-func-dumper.test to test pretty dumping of variadic
  functions.

Reviewers: zturner, llvm-commits

Reviewed By: zturner

Differential Revision: https://reviews.llvm.org/D41801

llvm-svn: 322608
2018-01-17 01:22:03 +00:00