Commit Graph

24120 Commits

Author SHA1 Message Date
Alex Lorenz
c9a4f3d5d9 MIR Serialization: Serialize simple MachineRegisterInfo attributes.
This commit serializes the 3 scalar boolean attributes from the
MachineRegisterInfo class: IsSSA, TracksRegLiveness, and
TracksSubRegLiveness. These attributes are serialized as part
of the machine function YAML mapping.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10618


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240579 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 19:56:10 +00:00
Rafael Espindola
9fa0ab3335 Add a SymbolRef::getValue.
This returns either the symbol offset or address. Since it is not defined which
one, it never has to lookup the section and so never fails.

I will add users in the next commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240569 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 19:11:10 +00:00
Pete Cooper
234c5890e7 Devirtualize Constant::replaceUsesOfWithOnConstant.
This is part of the work to devirtualize Value.

The old pattern was to call replaceUsesOfWithOnConstant which was overridden by
subclasses.  Those could then call replaceUsesOfWithOnConstantImpl on Constant
to handle deleting the current value.

To be consistent with other parts of the code, this has been changed so that we
call the method on Constant, and that dispatches to an Impl on subclasses.

As part of this, it made sense to rename the methods to be more descriptive.  The
new name is Constant::handleOperandChange, and it requires that all subclasses of
Constant implement handleOperandChangeImpl, even if they just throw an error if
they shouldn't be called.

Reviewed by Duncan Exon Smith.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240567 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 18:55:24 +00:00
Duncan P. N. Exon Smith
a0b5a74966 AsmPrinter: Cleanup DIEValue::EmitValue() API, NFC
Stop taking a `dwarf::Form` in `DIEValue::EmitValue()` and
`DIEValue::SizeOf()`, since they're always passed `DIEValue::getForm()`
anyway.  This is just left over from when `DIEValue` didn't know its own
form.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240566 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 18:48:11 +00:00
Rafael Espindola
262e948d2a Refactor duplicated code. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240563 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 18:14:41 +00:00
Bruno Cardoso Lopes
1b6ca9d0cc [CaptureTracking] Avoid long compilation time on large basic blocks
CaptureTracking becomes very expensive in large basic blocks while
calling PointerMayBeCaptured. PointerMayBeCaptured scans the BB the
number of times equal to the number of uses of 'BeforeHere', which is
currently capped at 20 and bails out with Tracker->tooManyUses().

The bottleneck here is the number of calls to PointerMayBeCaptured * the
basic block scan. In a testcase with a 82k instruction BB,
PointerMayBeCaptured is called 130k times, leading to 'shouldExplore'
taking 527k runs, this currently takes ~12min.

To fix this we locally (within PointerMayBeCaptured) number the
instructions in the basic block using a DenseMap to cache instruction
positions/numbers. We build the cache incrementally every time we need
to scan an unexplored part of the BB, improving compile time to only
take ~2min.

This triggers in the flow: DeadStoreElimination -> MepDepAnalysis ->
CaptureTracking.

Side note: after multiple runs in the test-suite I've seen no
performance nor compile time regressions, but could note a couple of
compile time improvements:

Performance Improvements - Compile Time Delta Previous  Current StdDev
SingleSource/Benchmarks/Misc-C++/bigfib -4.48%  0.8547  0.8164  0.0022
MultiSource/Benchmarks/TSVC/LoopRerolling-dbl/LoopRerolling-dbl -1.47% 1.3912  1.3707  0.0056

Differential Revision: http://reviews.llvm.org/D7010

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240560 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 17:53:17 +00:00
Rafael Espindola
1e6b8f552c Don't get confused with sections whose section number is reserved.
It is perfectly possible for SHNDX to contain indexes that have the same value
as reserved st_shndx values.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240544 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 14:48:54 +00:00
Rafael Espindola
821b06f3a8 Change how symbol sizes are handled in lib/Object.
COFF and MachO only define symbol sizes for common symbols. Reflect that
in the class hierarchy by having a method for common symbols only in the base
and a general one in ELF.

This avoids the need of using a magic value for the size, which had a few
problems
* Most callers didn't check for it.
* The ones that did could not tell the magic value from a file actually having
  that value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240529 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 10:20:30 +00:00
Chandler Carruth
9ece8eb945 [ADT] Teach DenseMap to support StringRef keys.
While often you want to use something specialized like StringMap, when
the strings already have persistent storage a normal densemap over them
can be more efficient.

This can't go into StringRef.h because of really obnoxious header chains
from the hashing code to the endian detection code to CPU feature
detection code to StringMap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240528 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 10:06:29 +00:00
Craig Topper
1405564987 [TableGen] Restore the use of the TheInit field in Record to cache the Record's DefInit. I broke this when I fixed memory leaks recently. Remove the DenseMap that mapped Record's to DefInit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240524 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 06:19:19 +00:00
Bob Wilson
bfb1922670 Do not treat ARM _MoveToCoprocessor* intrinsics as MSBuiltins.
Those builtins are now handled via ad-hoc code in clang with r240522 to
deal with reordering the arguments to fix PR22560.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240523 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 06:07:41 +00:00
Rafael Espindola
9073b8fb67 Don't repeat name in comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240516 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 03:19:35 +00:00
Pete Cooper
eab3c6548c Remove unused GlobalVariable::replaceUsesOfWithOnConstant. NFC.
The only caller of this method is Value::replaceAllUsesWith which
explicitly checks that we are not a GlobalValue.  So replace the
body with an unreachable to ensure that we never call it.

The unreachable itself is moved to GlobalValue not GlobalVariable
as that is the base class of all the globals we don't want to call
this method on.

Note, this patch is short lived as i'll soon refactor all callers
of this method.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240486 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 00:05:07 +00:00
Alex Lorenz
926d65d4f7 MIR Parser: Use correct source locations for machine instruction diagnostics.
This commit translates the source locations for MIParser diagnostics from
the locations in the machine instruction string to the locations in the
MIR file.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10574


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240474 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 22:39:23 +00:00
Pete Cooper
d621812aac Devirtualize Constant::destroyConstant.
This reorganizes destroyConstant and destroyConstantImpl.

Now there is only destroyConstant in Constant itself, while
subclasses are required to implement destroyConstantImpl.

destroyConstantImpl no longer calls delete but is instead only
responsible for removing the constant from any maps in which it
is contained.

Reviewed by Duncan Exon Smith.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240471 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 21:55:11 +00:00
Alexey Samsonov
a9a3bc268b Let llvm::ReplaceInstWithInst copy debug location from old to new instruction.
Currently some users of this function do this explicitly, and all the
rest forget to do this.

ThreadSanitizer was one of such users, and had missing debug
locations for calls into TSan runtime handling atomic operations,
eventually leading to poorly symbolized stack traces and malfunctioning
suppressions.

This is another change relevant to PR23837.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240460 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 21:00:08 +00:00
Sanjoy Das
ef42e1115f Revert "[FaultMaps] Move FaultMapParser to Object/"
This reverts commit r240364 (git c49542e5bb).  The issue r240364 was
trying to fix was fixed independently in r240362.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240448 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 20:09:03 +00:00
Alex Lorenz
1c5cf241af ADT: Add a string APSInt constructor.
This commit moves the APSInt initialization code that's used by
the LLLexer class into a new APSInt constructor that constructs
APSInts from strings.

This change is useful for MIR Serialization, as it would allow
the MILexer class to use the same APSInt initialization as 
LLexer when parsing immediate machine operands.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240436 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 18:22:10 +00:00
Alex Lorenz
d31dc69aa1 AsmParser: Extend the API to make the global value and metadata node slot mappings publicly accessible.
This commit creates a new structure called 'SlotMapping' in the AsmParser library.
This structure can be passed into the public parsing APIs from the AsmParser library
in order to extract the data structures that map from slot numbers to unnamed global
values and metadata nodes.

This change is useful for MIR Serialization, as the MIR Parser has to lookup the
unnamed global values and metadata nodes by their slot numbers.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10551


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240427 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 17:10:10 +00:00
Tom Stellard
3edc38d967 ELF: Fix defintion of STT_LOOS and STT_HIOS.
Reviewers: chandlerc, Bigcheese, rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10647

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240426 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 16:41:57 +00:00
Benjamin Kramer
896353d663 [Option] Plug a leak when move-assigning an InputArgList.
The class has a non-trivial dtor so we have to clean up before we move
in new members. Remove misleading comment as a default move assignment
operator will never be synthesized for this class.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240417 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 15:28:10 +00:00
Benjamin Kramer
336ead08bd [MachineBasicBlock] Add getFirstNonDebugInstr to complement getLastNonDebugInstr
Use it in CodeGen where applicable. No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240414 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 14:47:29 +00:00
Benjamin Kramer
d18bb88b2e [MachineBasicBlock] Use the const_cast(this) trick to reduce duplication
NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240413 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 14:47:18 +00:00
Rafael Espindola
0e9288493a Remove unused arguments and move ManglerPrefixTy to the implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240408 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 14:11:09 +00:00
Rafael Espindola
9758b4ae95 Simplify the Mangler interface now that DataLayout is mandatory.
We only need to pass in a DataLayout when mangling a raw string, not when
constructing the mangler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240405 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 13:59:29 +00:00
Rafael Espindola
7737c637f0 Don't repeat names in comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240396 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 12:29:52 +00:00
Rafael Espindola
b9ed9af341 Use MCSymbols for FastISel.
The summary is that it moves the mangling earlier and replaces a few
calls to .addExternalSymbol with addSym.

I originally wanted to replace all the uses of addExternalSymbol with
addSym, but noticed it was a lot of work and doesn't need to be done
all at once.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240395 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 12:21:54 +00:00
Daniel Jasper
b7f5b8b4b2 Revert r240302 ("Bring r240130 back.").
This causes errors like:

  ld: error: blah.o: requires dynamic R_X86_64_PC32 reloc against '' which
  may overflow at runtime; recompile with -fPIC
  blah.cc:function f(): error: undefined reference to ''
  blah.o:g(): error: undefined reference to ''

I have not yet come up with an appropriate reproduction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240394 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 11:31:32 +00:00
Alexander Kornienko
b7c46b5fc9 Revert r240271 (Fixed/added namespace ending comments using clang-tidy. NFC)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240393 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 10:48:35 +00:00
Alexander Kornienko
cd52a7a381 Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240390 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 09:49:53 +00:00
Elena Demikhovsky
d96e362b3f AVX-512: Added all forms of VPABS instruction
Added all intrinsics, tests for encoding, tests for intrinsics.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240386 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 08:19:46 +00:00
Rafael Espindola
9e7539a79f Remove broken banner.
Thanks to Filipe Cabecinhas for noticing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240375 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 03:45:23 +00:00
Rafael Espindola
344dd6519e Extract an utility for computing symbol sizes on MachO and COFF.
I will add a second user in the next commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240366 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 02:08:48 +00:00
Sanjoy Das
c49542e5bb [FaultMaps] Move FaultMapParser to Object/
Summary:
That way llvm-objdump can rely on it without adding an extra dependency
on CodeGen.

This change duplicates the FaultKind enum and the code that serializes
it to a string.  I could not figure out a way to get around this without
adding a new dependency to Object

Reviewers: rafael, ab

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10619

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240364 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 01:05:26 +00:00
Sanjoy Das
14b492752c Fix a typo in a comment in FaultMaps.h. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240363 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 01:05:21 +00:00
Justin Bogner
b06f3b4a33 Re-apply "InstrProf: When reading, copy the data instead of taking a reference. NFC"
This version fixes a missing include that MSVC noticed and
clarifies the ownership of the counter buffer that's passed to
InstrProfRecord.

This restores r240206, which was reverted in r240208.

Patch by Betul Buyukkurt.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240360 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 23:58:05 +00:00
Pete Cooper
46a3ee7346 Create Value.def helper. NFC.
This is similar to Metadata.def and Instructions.def but for Value's.

It will be used in upcoming commits to devirtualize the Value class.

Reviewed by Duncan Exon Smith.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240358 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 23:48:35 +00:00
David Blaikie
0c17f95006 Modify ParseArgs to return the InputArgList by value - there's no need for dynamic allocation/ownership here
The one caller that does anything other than keep this variable on the
stack is the single use of DerivedArgList in Clang, which is a bit more
interesting but can probably be cleaned up/simplified a bit further
(have DerivedArgList take ownership of the InputArgList rather than
needing to reference its Args indirectly) which I'll try to after this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240345 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 22:06:37 +00:00
Joseph Tremoulet
864619a387 Fix line endings (NFC)
I inadvertently checked these in with Windows-style line
endings in r240288.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240340 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 21:37:34 +00:00
Frederic Riss
11fcb49922 [Object] Search for architecures by name in MachOUniversalBinary::getObjectForArch()
The reason we need to search by name rather than by Triple::ArchType
is to handle subarchitecture correclty. There is no different ArchType
for the x86_64h architecture (it identifies itself as x86_64), or for
the various ARM subarches. The only way to get to the subarch slice
in an universal binary is to search by name.

This issue led to hard to debug and transient symbolication failures
in Asan tests (it mostly works, because the files are very similar).

This also affects the Profiling infrastucture as it is the other user
of that API.

Reviewers: samsonov, bogner

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10604

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240339 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 21:33:24 +00:00
Tom Stellard
b53953a84f Support/ELF: Add EM_AMDGPU
Summary: This will be used by the R600 backend.

Reviewers: chandlerc, rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10389

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240329 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 21:03:47 +00:00
Pete Cooper
8b4b91acd8 Move MCSymbol Value in to the union of Offset and CommonSize.
This is a reapplication of r239440 which was reverted in r239441.
There are no changes to this patch from then, but this had instead exposed
a bug in .thumb_set which was fixed in r240318.  Having fixed that bug, it
is now safe to re-apply this code.

Original commit message below:

It wasn't possible to have a variable Symbol with offset or 'isCommon' so
this just enables better packing of the MCSymbol class.

Reviewed by Rafael Espindola.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240320 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 19:57:33 +00:00
Pete Cooper
54d0bc35fe Change .thumb_set to have the same error checks as .set.
According to the documentation, .thumb_set is 'the equivalent of a .set directive'.

We didn't have equivalent behaviour in terms of all the errors we could throw, for
example, when a symbol is redefined.

This change refactors parseAssignment so that it can be used by .set and .thumb_set
and implements tests for .thumb_set for all the errors thrown by that method.

Reviewed by Rafael Espíndola.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240318 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 19:35:57 +00:00
Krzysztof Parzyszek
18693ad79a Remove "const" from the MachineFunction reference in VLIWPacketizerList
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240317 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 18:59:44 +00:00
Sanjoy Das
060e38ab9f Fix MSVC build (again!).
Remove two `typename`s that I should have removed in r240307 but left in
by mistake.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240309 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 18:24:50 +00:00
Sanjoy Das
e0ef46e5e7 [FaultMaps] Add a parser for the __llvm__faultmaps section.
Summary:
The parser is exercised by llvm-objdump using -print-fault-maps.  As is
probably obvious, the code itself was "heavily inspired" by
http://reviews.llvm.org/D10434.

Reviewers: reames, atrick, JosephTremoulet

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10491

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240304 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 18:03:02 +00:00
Rafael Espindola
afd779f72d Bring r240130 back.
Now that pr23900 is fixed, we can bring it back with no changes.

Original message:

Make all temporary symbols unnamed.

What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.

Some of these symbols still show up in the symbol table, but we can just
make them unnamed.

In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.

Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240302 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 17:52:52 +00:00
Rafael Espindola
09bbd16112 Avoid a Symbol -> Name -> Symbol conversion.
Before this we were producing a TargetExternalSymbol from a MCSymbol.
That meant extracting the symbol name and fetching the symbol again
down the pipeline.

This patch adds a DAG.getMCSymbol that lets the MCSymbol pass unchanged on the
DAG.

Doing so removes the need for MO_NOPREFIX and fixes the root cause of pr23900,
allowing r240130 to be committed again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240300 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 17:46:53 +00:00
Alex Lorenz
2f801faafb MIR Serialization: Serialize machine instruction names.
This commit implements initial machine instruction serialization. It
serializes machine instruction names. The instructions are represented
using a YAML sequence of string literals and are a part of machine
basic block YAML mapping.

This commit introduces a class called 'MIParser' which will be used to
parse the machine instructions and operands.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10481


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240295 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 17:02:30 +00:00
Joseph Tremoulet
c29284e6c3 [ORC] Add NullResolver
Summary:
This is an implementation of RuntimeDyld::SymbolResolver that simply
rejects all resolution requests; useful for clients that do not have any
cross-object symbol references.

Reviewers: lhames

Reviewed By: lhames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10455

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240288 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 15:27:58 +00:00