Commit Graph

194 Commits

Author SHA1 Message Date
Kazu Hirata
586ecdf205
[llvm] Use StringRef::{starts,ends}_with (NFC) (#74956)
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.

I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
2023-12-11 21:01:36 -08:00
Fangrui Song
d0d1c416cb Remove unneeded cl::ZeroOrMore for cl::list options 2022-06-04 23:51:13 -07:00
Keith Smiley
2569f79a4f
[llvm-dis] Improve missing file error message
Previously the error message didn't include the failing path, which made
it hard to tell what went wrong.

Differential Revision: https://reviews.llvm.org/D121665
2022-05-19 11:07:49 -07:00
serge-sans-paille
1237c1496f Cleanup LLVMBitcode headers
Major user-facing changes:
llvm/Bitcode/BitcodeReader.h no longer includes llvm/IR/ModuleSummaryIndex.h

Some statistics:
clang++ -E  -Iinclude -I../llvm/include ../llvm/lib/Bitcode/Reader/*.cpp -std=c++14 -fno-rtti -fno-exceptions | wc -l
after: 493335
before: 539640

Discourse thread on the topic: https://discourse.llvm.org/t/include-what-you-use-include-cleanup/

Differential Revision: https://reviews.llvm.org/D119091
2022-02-07 21:19:22 +01:00
minglotus-6
e95ad93e6e [llvm-dis] Add an option dump-thinlto-index-only in llvm-dis to read ThinLTO minimized code only. 2022-01-19 18:07:50 -08:00
Timm Bäder
669275f8a0 [llvm][tools] Hide more unrelated tool options
Differential Revision: https://reviews.llvm.org/D106271
2021-07-20 13:27:33 +02:00
Arthur Eubanks
4c8174f54b [OpaquePtr] Introduce option to force all pointers to be opaque pointers
We don't want to start updating tests to use opaque pointers until we're
close to the opaque pointer transition. However, before the transition
we want to run tests as if pointers are opaque pointers to see if there
are any crashes.

At some point when we have a flag to only create opaque pointers in the
bitcode and textual IR readers, and when we have fixed all places that
try to read a pointee type, this flag will be useless. However, until
then, this can help us find issues more easily.

Since the cl::opt is read into LLVMContext, we need to make sure
LLVMContext is created after cl::ParseCommandLineOptions().

Previously ValueEnumerator would visit the value types of global values
via the pointer type, but with opaque pointers we have to manually visit
the value type.

Reviewed By: nikic, dexonsmith

Differential Revision: https://reviews.llvm.org/D103503
2021-06-24 13:32:31 -07:00
Matthew Voss
22aece57be Allow llvm-dis to disassemble multiple files
Differential Revision: https://reviews.llvm.org/D101110
2021-05-06 11:08:55 -07:00
Abhina Sreeskantharajan
82b3e28e83 [SystemZ][z/OS][Windows] Add new OF_TextWithCRLF flag and use this flag instead of OF_Text
Problem:
On SystemZ we need to open text files in text mode. On Windows, files opened in text mode adds a CRLF '\r\n' which may not be desirable.

Solution:
This patch adds two new flags

  - OF_CRLF which indicates that CRLF translation is used.
  - OF_TextWithCRLF = OF_Text | OF_CRLF indicates that the file is text and uses CRLF translation.

Developers should now use either the OF_Text or OF_TextWithCRLF for text files and OF_None for binary files. If the developer doesn't want carriage returns on Windows, they should use OF_Text, if they do want carriage returns on Windows, they should use OF_TextWithCRLF.

So this is the behaviour per platform with my patch:

z/OS:
OF_None: open in binary mode
OF_Text : open in text mode
OF_TextWithCRLF: open in text mode

Windows:
OF_None: open file with no carriage return
OF_Text: open file with no carriage return
OF_TextWithCRLF: open file with carriage return

The Major change is in llvm/lib/Support/Windows/Path.inc to only set text mode if the OF_CRLF is set.
```
  if (Flags & OF_CRLF)
    CrtOpenFlags |= _O_TEXT;
```

These following files are the ones that still use OF_Text which I left unchanged. I modified all these except raw_ostream.cpp in recent patches so I know these were previously in Binary mode on Windows.
./llvm/lib/Support/raw_ostream.cpp
./llvm/lib/TableGen/Main.cpp
./llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
./llvm/unittests/Support/Path.cpp
./clang/lib/StaticAnalyzer/Core/HTMLDiagnostics.cpp
./clang/lib/Frontend/CompilerInstance.cpp
./clang/lib/Driver/Driver.cpp
./clang/lib/Driver/ToolChains/Clang.cpp

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D99426
2021-04-06 07:23:31 -04:00
serge-sans-paille
9218ff50f9 llvmbuildectomy - replace llvm-build by plain cmake
No longer rely on an external tool to build the llvm component layout.

Instead, leverage the existing `add_llvm_componentlibrary` cmake function and
introduce `add_llvm_component_group` to accurately describe component behavior.

These function store extra properties in the created targets. These properties
are processed once all components are defined to resolve library dependencies
and produce the header expected by llvm-config.

Differential Revision: https://reviews.llvm.org/D90848
2020-11-13 10:35:24 +01:00
Matthew Voss
e69a7364f2 [llvm-dis] Fix the disable-output flag
My change in llvmorg-10-init-9872-g141bb5f308f broke this flag.

Thanks to @rsmith for the bug.
2019-11-14 13:35:21 -08:00
Matthew Voss
141bb5f308 Add support for multi-module bitcode files to llvm-dis
Summary:
This change allows llvm-dis to disassemble multi-module bitcode
files, including the associated module summary.

Reviewers: tejohnson, pcc, mehdi_amini

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70153
2019-11-14 10:40:41 -08:00
Kai Nacke
c9ddda8405 [Tools] Mark output of tools as text if it is text
Several LLVM tools write text files/streams without using OF_Text.
This can cause problems on platforms which distinguish between
text and binary output. This PR adds the OF_Text flag for the
following tools:

- llvm-dis
- llvm-dwarfdump
- llvm-mca
- llvm-mc (assembler files only)
- opt (assembler files only)
- RemarkStreamer (used e.g. by opt)

Reviewers: rnk, vivekvpandya, Bigcheese, andreadb

Differential Revision: https://reviews.llvm.org/D67696

llvm-svn: 374024
2019-10-08 08:21:20 +00:00
Jonas Devlieghere
0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Fangrui Song
d9b948b6eb Rename F_{None,Text,Append} to OF_{None,Text,Append}. NFC
F_{None,Text,Append} are kept for compatibility since r334221.

llvm-svn: 367800
2019-08-05 05:43:48 +00:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Teresa Johnson
08d5b4ef0d [ThinLTO] Print module summary index to assembly
Summary:
Implements AsmWriter support for printing the module summary index to
assembly with the format discussed in the RFC "LLVM Assembly format for
ThinLTO Summary".

Implements just enough of the parsing support to recognize and ignore
the summary entries. As agreed in the RFC thread, this will be the
behavior when assembling the IR. A follow on change will implement
parsing/assembling of the summary entries for use by tools that
currently build the summary index from bitcode.

Reviewers: dexonsmith, pcc

Subscribers: inglorion, eraman, steven_wu, dblaikie, llvm-commits

Differential Revision: https://reviews.llvm.org/D46699

llvm-svn: 333335
2018-05-26 02:34:13 +00:00
Jonas Devlieghere
2cd41eb058 [tools] Use WithColor for printing errors.
Use convenience helpers in WithColor to print errors, warnings and notes
in a few more tools.

llvm-svn: 330524
2018-04-21 21:11:59 +00:00
Rui Ueyama
197194b6c9 Define InitLLVM to do common initialization all at once.
We have a few functions that virtually all command wants to run on
process startup/shutdown. This patch adds InitLLVM class to do that
all at once, so that we don't need to copy-n-paste boilerplate code
to each llvm command's main() function.

Differential Revision: https://reviews.llvm.org/D45602

llvm-svn: 330046
2018-04-13 18:26:06 +00:00
Reid Kleckner
3fc649cb76 [Support] Rename tool_output_file to ToolOutputFile, NFC
This class isn't similar to anything from the STL, so it shouldn't use
the STL naming conventions.

llvm-svn: 314050
2017-09-23 01:03:17 +00:00
Vivek Pandya
b5ab895e2a This patch fixes https://bugs.llvm.org/show_bug.cgi?id=32352
It enables OptimizationRemarkEmitter::allowExtraAnalysis and MachineOptimizationRemarkEmitter::allowExtraAnalysis to return true not only for -fsave-optimization-record but when specific remarks are requested with
command line options.
The diagnostic handler used to be callback now this patch adds a class
DiagnosticHandler. It has virtual method to provide custom diagnostic handler
and methods to control which particular remarks are enabled. 
However LLVM-C API users can still provide callback function for diagnostic handler.

llvm-svn: 313390
2017-09-15 20:10:09 +00:00
Vivek Pandya
df8598dcc4 This reverts r313381
llvm-svn: 313387
2017-09-15 19:53:54 +00:00
Vivek Pandya
00d887447b This patch fixes https://bugs.llvm.org/show_bug.cgi?id=32352
It enables OptimizationRemarkEmitter::allowExtraAnalysis and MachineOptimizationRemarkEmitter::allowExtraAnalysis to return true not only for -fsave-optimization-record but when specific remarks are requested with
command line options.
The diagnostic handler used to be callback now this patch adds a class
DiagnosticHandler. It has virtual method to provide custom diagnostic handler
and methods to control which particular remarks are enabled. 
However LLVM-C API users can still provide callback function for diagnostic handler.

llvm-svn: 313382
2017-09-15 19:30:59 +00:00
Charles Saternos
55d93e79df [ThinLTO] Fix ThinLTO crash while destroying context
Fix for PR32763

An assert that checks if a Ref was untracked fails during ThinLTO context cleanup. The issue is because lazy loading temporary nodes didn't properly track ValueAsMetadata nodes. This patch ensures that the temporary nodes are properly tracked when they're replaced with the value.

llvm-svn: 310967
2017-08-15 22:23:44 +00:00
Chris Bieneman
e525ef9cd1 [CMake] llvm-dis depends on intrinsics_gen
llvm-dis.cpp has the following include chain:

llvm/Bitcode/BitcodeReader.h
llvm/IR/ModuleSummaryIndex.h
llvm/IR/Module.h
llvm/IR/Function.h
llvm/IR/Argument.h
llvm/IR/Attributes.h
llvm/IR/Attributes.gen

This means llvm-dis needs to depend on intrinsics_gen.

llvm-svn: 287428
2016-11-19 02:31:14 +00:00
Peter Collingbourne
bda4498543 llvm-dis: Remove dead code.
llvm-svn: 287182
2016-11-17 00:42:08 +00:00
Peter Collingbourne
d9445c49ad Bitcode: Change module reader functions to return an llvm::Expected.
Differential Revision: https://reviews.llvm.org/D26562

llvm-svn: 286752
2016-11-13 07:00:17 +00:00
Teresa Johnson
ad17679abd Split Bitcode/ReaderWriter.h into separate reader and writer headers
Summary:
Split ReaderWriter.h which contains the APIs into both the BitReader and
BitWriter libraries into BitcodeReader.h and BitcodeWriter.h.

This is to address Chandler's concern about sharing the same API header
between multiple libraries (BitReader and BitWriter). That concern is
why we create a single bitcode library in our downstream build of clang,
which led to r286297 being reverted as it added a dependency that
created a cycle only when there is a single bitcode library (not two as
in upstream).

Reviewers: mehdi_amini

Subscribers: dlj, mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D26502

llvm-svn: 286566
2016-11-11 05:34:58 +00:00
Peter Collingbourne
7f00d0a125 Bitcode: Change the materializer interface to return llvm::Error.
Differential Revision: https://reviews.llvm.org/D26439

llvm-svn: 286382
2016-11-09 17:49:19 +00:00
Peter Collingbourne
e2dcf7c3a1 IR, Bitcode: Change bitcode reader to no longer own its memory buffer.
Unique ownership is just one possible ownership pattern for the memory buffer
underlying the bitcode reader. In practice, as this patch shows, ownership can
often reside at a higher level. With the upcoming change to allow multiple
modules in a single bitcode file, it will no longer be appropriate for
modules to generally have unique ownership of their memory buffer.

The C API exposes the ownership relation via the LLVMGetBitcodeModuleInContext
and LLVMGetBitcodeModuleInContext2 functions, so we still need some way for
the module to own the memory buffer. This patch does so by adding an owned
memory buffer field to Module, and using it in a few other places where it
is convenient.

Differential Revision: https://reviews.llvm.org/D26384

llvm-svn: 286214
2016-11-08 06:03:43 +00:00
Peter Collingbourne
028eb5a3f8 Bitcode: Change reader interface to take memory buffers.
As proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/106595.html

This change also fixes an API oddity where BitstreamCursor::Read() would
return zero for the first read past the end of the bitstream, but would
report_fatal_error for subsequent reads. Now we always report_fatal_error
for all reads past the end. Updated clients to check for the end of the
bitstream before reading from it.

I also needed to add padding to the invalid bitcode tests in
test/Bitcode/. This is because the streaming interface was not checking that
the file size is a multiple of 4.

Differential Revision: https://reviews.llvm.org/D26219

llvm-svn: 285773
2016-11-02 00:08:19 +00:00
Peter Collingbourne
21521891a2 IR: Allow metadata attachments on declarations, and fix lazy loaded metadata issue with globals.
This change is motivated by an upcoming change to the metadata representation
used for CFI. The indirect function call checker needs type information for
external function declarations in order to correctly generate jump table
entries for such declarations. We currently associate such type information
with declarations using a global metadata node, but I plan [1] to move all
such metadata to global object attachments.

In bitcode, metadata attachments for function declarations appear in the
global metadata block. This seems reasonable to me because I expect metadata
attachments on declarations to be uncommon. In the long term I'd also expect
this to be the case for CFI, because we'd want to use some specialized bitcode
format for this metadata that could be read as part of the ThinLTO thin-link
phase, which would mean that it would not appear in the global metadata block.

To solve the lazy loaded metadata issue I was seeing with D20147, I use the
same bitcode representation for metadata attachments for global variables as I
do for function declarations. Since there's a use case for metadata attachments
in the global metadata block, we might as well use that representation for
global variables as well, at least until we have a mechanism for lazy loading
global variables.

In the assembly format, the metadata attachments appear after the "declare"
keyword in order to avoid a parsing ambiguity.

[1] http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html

Differential Revision: http://reviews.llvm.org/D21052

llvm-svn: 273336
2016-06-21 23:42:48 +00:00
Richard Smith
2ad6d48b0c Search for llvm-symbolizer binary in the same directory as argv[0], before
looking for it along $PATH. This allows installs of LLVM tools outside of
$PATH to find the symbolizer and produce pretty backtraces if they crash.

llvm-svn: 272232
2016-06-09 00:53:21 +00:00
Mehdi Amini
03b42e41bf Remove every uses of getGlobalContext() in LLVM (but the C API)
At the same time, fixes InstructionsTest::CastInst unittest: yes
you can leave the IR in an invalid state and exit when you don't
destroy the context (like the global one), no longer now.

This is the first part of http://reviews.llvm.org/D19094

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266379
2016-04-14 21:59:01 +00:00
Chris Bieneman
e49730d4ba Remove autoconf support
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html

"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi

Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark

Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D16471

llvm-svn: 258861
2016-01-26 21:29:08 +00:00
Rafael Espindola
c4a03483f4 Drop materializeAllPermanently.
This inlines materializeAll into the only caller
(materializeAllPermanently) and renames materializeAllPermanently to
just materializeAll.

llvm-svn: 256024
2015-12-18 20:13:39 +00:00
Rafael Espindola
1aabf982bc Use std::unique_ptr to manage the DataStreamer in bitcode parsing.
We were already deleting it, this just makes it explicit.

llvm-svn: 239867
2015-06-16 23:29:49 +00:00
Alexey Samsonov
d923508782 Fix input validation issues in llvm-as/llvm-dis
Summary:
1. llvm-as/llvm-dis tools do not check for input filename length.
2. llvm-dis does not verify the `Streamer` variable against `nullptr` properly, so the `M` variable could be uninitialized (e.g. if the input file does not exist) leading to null dref.

Patch by Lenar Safin!

Reviewers: samsonov

Reviewed By: samsonov

Subscribers: samsonov, llvm-commits

Differential Revision: http://reviews.llvm.org/D9584

llvm-svn: 237051
2015-05-11 21:20:20 +00:00
Duncan P. N. Exon Smith
a9308c49ef IR: Give 'DI' prefix to debug info metadata
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`.  The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.

Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one.  It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs.  YMMV of
course.

Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py.  I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three.  It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).

Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.

llvm-svn: 236120
2015-04-29 16:38:44 +00:00
Duncan P. N. Exon Smith
60635e39b6 DebugInfo: Drop rest of DIDescriptor subclasses
Delete the remaining subclasses of (the already deleted) `DIDescriptor`.
Part of PR23080.

llvm-svn: 235404
2015-04-21 18:44:06 +00:00
Duncan P. N. Exon Smith
8a7b84b4d0 uselistorder: Remove the global bits
Remove all the global bits to do with preserving use-list order by
moving the `cl::opt`s to the individual tools that want them.  There's a
minor functionality change to `libLTO`, in that you can't send in
`-preserve-bc-uselistorder=false`, but making that bit settable (if it's
worth doing) should be through explicit LTO API.

As a drive-by fix, I removed some includes of `UseListOrder.h` that were
made unnecessary by recent commits.

llvm-svn: 234973
2015-04-15 03:14:06 +00:00
Duncan P. N. Exon Smith
c4f0a325a7 uselistorder: Pull the assembly bit up out of the printer
Pull the `-preserve-ll-uselistorder` bit up through all the callers of
`Module::print()`.  I converted callers of `operator<<` to
`Module::print()` where necessary to pull the bit through.

llvm-svn: 234968
2015-04-15 02:12:41 +00:00
Duncan P. N. Exon Smith
7348ddaa74 DebugInfo: Gut DIVariable and DIGlobalVariable
Gut all the non-pointer API from the variable wrappers, except an
implicit conversion from `DIGlobalVariable` to `DIDescriptor`.  Note
that if you're updating out-of-tree code, `DIVariable` wraps
`MDLocalVariable` (`MDVariable` is a common base class shared with
`MDGlobalVariable`).

llvm-svn: 234840
2015-04-14 02:22:36 +00:00
Duncan P. N. Exon Smith
b8afdd6044 llvm-dis: Use the new DebugLoc API, NFC
Update tools/llvm-dis to use the new `DebugLoc` API.

llvm-svn: 233590
2015-03-30 20:04:06 +00:00
Duncan P. N. Exon Smith
a6b8895442 llvm-dis: Stop crashing when dropping debug info
Since r199356, we've printed a warning when dropping debug info.
r225562 started crashing on that, since it registered a diagnostic
handler that only expected errors.  This fixes the handler to expect
other severities.  As a side effect, it now prints "error: " at the
start of error messages, similar to `llvm-as`.

There was a testcase for r199356, but it only really checked the
assembler.  Move `test/Bitcode/drop-debug-info.ll` to `test/Assembler`,
and introduce `test/Bitcode/drop-debug-info.3.5.ll` (and companion
`.bc`) to test the bitcode reader.

Note: tools/gold/gold-plugin.cpp has an equivalent bug, but I'm not sure
what the best fix is there.  I'll file a PR.

llvm-svn: 230416
2015-02-25 01:10:03 +00:00
Rafael Espindola
d0b23bef6f Use the DiagnosticHandler to print diagnostics when reading bitcode.
The bitcode reading interface used std::error_code to report an error to the
callers and it is the callers job to print diagnostics.

This is not ideal for error handling or diagnostic reporting:

* For error handling, all that the callers care about is 3 possibilities:
  * It worked
  * The bitcode file is corrupted/invalid.
  * The file is not bitcode at all.

* For diagnostic, it is user friendly to include far more information
  about the invalid case so the user can find out what is wrong with the
  bitcode file. This comes up, for example, when a developer introduces a
  bug while extending the format.

The compromise we had was to have a lot of error codes.

With this patch we use the DiagnosticHandler to communicate with the
human and std::error_code to communicate with the caller.

This allows us to have far fewer error codes and adds the infrastructure to
print better diagnostics. This is so because the diagnostics are printed when
he issue is found. The code that detected the problem in alive in the stack and
can pass down as much context as needed. As an example the patch updates
test/Bitcode/invalid.ll.

Using a DiagnosticHandler also moves the fatal/non-fatal error decision to the
caller. A simple one like llvm-dis can just use fatal errors. The gold plugin
needs a bit more complex treatment because of being passed non-bitcode files. An
hypothetical interactive tool would make all bitcode errors non-fatal.

llvm-svn: 225562
2015-01-10 00:07:30 +00:00
Rafael Espindola
7d727b5f11 Modernize the getStreamedBitcodeModule interface a bit. NFC.
llvm-svn: 224499
2014-12-18 05:08:43 +00:00
Rafael Espindola
3fd1e9933f Modernize raw_fd_ostream's constructor a bit.
Take a StringRef instead of a "const char *".
Take a "std::error_code &" instead of a "std::string &" for error.

A create static method would be even better, but this patch is already a bit too
big.

llvm-svn: 216393
2014-08-25 18:16:47 +00:00
Rafael Espindola
4453e42945 Remove 'using std::error_code' from tools.
llvm-svn: 210876
2014-06-13 03:07:50 +00:00
Rafael Espindola
3acea39853 Don't use 'using std::error_code' in include/llvm.
This should make sure that most new uses use the std prefix.

llvm-svn: 210835
2014-06-12 21:46:39 +00:00