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77 Commits

Author SHA1 Message Date
Diego Novillo 2567f3d0fb Add function entry count metadata.
Summary:
This adds three Function methods to handle function entry counts:
setEntryCount() and getEntryCount().

Entry counts are stored under the MD_prof metadata node with the name
"function_entry_count". They are unsigned 64 bit values set by profilers
(instrumentation and sample profiler changes coming up).

Added documentation for new profile metadata and tests.

Reviewers: dexonsmith, bogner

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9628

llvm-svn: 237260
2015-05-13 15:13:45 +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 1ec75ae963 DebugInfo: Support up to 2^16 arguments in a subprogram
Support up to 2^16 arguments to a function.  If we do hit the limit,
assert out rather than restarting at 0 as we've done historically.

This fixes PR23332.  A clang test will follow.

llvm-svn: 235955
2015-04-28 01:07:33 +00:00
Duncan P. N. Exon Smith 327e9bd399 Verifier: Function metadata attachments require a body
Add a verifier check that only functions with bodies have metadata
attachments.  This should help catch bugs in frontends and
transformation passes.  Part of PR23340.

llvm-svn: 235784
2015-04-24 21:53:27 +00:00
Duncan P. N. Exon Smith e2510cdfe8 IR: Add Function metadata attachments
Add IR support for `Metadata` attachments.  Assembly and bitcode support
will follow shortly, but for now we just have unit tests.  This is part
of PR23340.

llvm-svn: 235783
2015-04-24 21:51:02 +00:00
Duncan P. N. Exon Smith f15c6f8032 DebugInfo: Gut DIDescriptor
PR23080 is almost finished.  With this commit, there's no consequential
API in `DIDescriptor` and its subclasses.  What's left?

  - Default-constructed to `nullptr`.
  - Handy `const_cast<>` (constructed from `const`, but accessors are
    non-`const`).

I think the safe way to catch those is to delete the classes and fix
compile errors.  That'll be my next step, after I delete the `DITypeRef`
(etc.) wrapper around `MDTypeRef`.

llvm-svn: 235069
2015-04-16 01:53:33 +00:00
Duncan P. N. Exon Smith 62e0f454a0 DebugInfo: Remove 'inlinedAt:' field from MDLocalVariable
Remove 'inlinedAt:' from MDLocalVariable.  Besides saving some memory
(variables with it seem to be single largest `Metadata` contributer to
memory usage right now in -g -flto builds), this stops optimization and
backend passes from having to change local variables.

The 'inlinedAt:' field was used by the backend in two ways:

 1. To tell the backend whether and into what a variable was inlined.
 2. To create a unique id for each inlined variable.

Instead, rely on the 'inlinedAt:' field of the intrinsic's `!dbg`
attachment, and change the DWARF backend to use a typedef called
`InlinedVariable` which is `std::pair<MDLocalVariable*, MDLocation*>`.
This `DebugLoc` is already passed reliably through the backend (as
verified by r234021).

This commit removes the check from r234021, but I added a new check
(that will survive) in r235048, and changed the `DIBuilder` API in
r235041 to require a `!dbg` attachment whose 'scope:` is in the same
`MDSubprogram` as the variable's.

If this breaks your out-of-tree testcases, perhaps the script I used
(mdlocalvariable-drop-inlinedat.sh) will help; I'll attach it to PR22778
in a moment.

llvm-svn: 235050
2015-04-15 22:29:27 +00:00
Duncan P. N. Exon Smith 7ad0bd54d3 DebugInfo: Make MDSubprogram::getFunction() return Constant
Change `MDSubprogram::getFunction()` and
`MDGlobalVariable::getConstant()` to return a `Constant`.  Previously,
both returned `ConstantAsMetadata`.

llvm-svn: 234699
2015-04-11 20:27:40 +00:00
Duncan P. N. Exon Smith 1134473f51 IR: Remove MDTupleTypedArrayWrapper::operator MDTuple*()
Remove `MDTupleTypedArrayWrapper::operator MDTuple*()`, since it causes
ambiguity (at least in some [1] compilers [2]) when using indexes to
`MDTupleTypedArrayWrapper::operator[](unsigned)` that are convertible to
(but not the same as) `unsigned`.

[1]: http://lab.llvm.org:8011/builders/sanitizer-windows/builds/2308
[2]: http://lab.llvm.org:8011/builders/clang-cmake-mips/builds/4442

llvm-svn: 234326
2015-04-07 16:50:39 +00:00
Duncan P. N. Exon Smith 5dcf621c8a IR: Rename MDSubrange::getLo() to getLowerBound()
During initial review, the `lo:` field was renamed to `lowerBound:`.
Make the same change to the C++ API.

llvm-svn: 234267
2015-04-07 00:39:59 +00:00
Duncan P. N. Exon Smith 3ec5fa6a1c DebugInfo: Use MDTypeRef throughout the hierarchy
Use `MDTypeRef` (etc.) in the new debug info hierarchy rather than raw
`Metadata *` pointers.

I rolled in a change to `DIBuilder` that looks unrelated: take `DIType`
instead of `DITypeRef` as type arguments when creating variables.
However, this was the simplest way to use `MDTypeRef` within the
functions, and didn't require any cleanups from callers in clang (since
they were all passing in `DIType`s anyway, relying on their implicit
conversions to `DITypeRef`).

llvm-svn: 234197
2015-04-06 19:03:45 +00:00
Duncan P. N. Exon Smith 014f1b83eb IR: Rename replaceWithUniqued() tests from r233751
replaceWithUniquedUnresolved
replaceWithUniquedUnresolvedChangedOperand
 =>
replaceWithUniquedResolvingOperand
replaceWithUniquedChangingOperand

I find the new names less confusing; they're also more accurate.  Sorry
for the churn.

llvm-svn: 233759
2015-03-31 21:05:06 +00:00
Duncan P. N. Exon Smith cb33d6f546 IR: Enable uniquing callbacks during MDNode::replaceWithUniqued()
Uniqued nodes have more complete registration with
`ReplaceableMetadataImpl` so that they can update themselves when
operands change.  Fix a bug where `MDNode::replaceWithUniqued()` wasn't
enabling these callbacks.

The two most obvious ways missing callbacks causes problems is that
auto-resolution fails and re-uniquing (on changed operands) just doesn't
happen.  I've added tests for both -- in both cases, I confirmed that
the final check was failing before the fix.

rdar://problem/20365935

llvm-svn: 233751
2015-03-31 20:50:50 +00:00
Duncan P. N. Exon Smith f9b4775c78 Verifier: Add operand checks for remaining debug info
llvm-svn: 233565
2015-03-30 17:21:38 +00:00
Duncan P. N. Exon Smith 0e202b95c4 Verifier: Add operand checks for MDLexicalBlock
Add operand checks for `MDLexicalBlock` and `MDLexicalBlockFile`.  Like
`MDLocalVariable` and `MDLocation`, these nodes always require a scope.

There was no test bitrot to fix here (just updated the serialization
tests in test/Assembler/mdlexicalblock.ll).

llvm-svn: 233561
2015-03-30 16:37:48 +00:00
Duncan P. N. Exon Smith 869db50ffd Verifier: Check operands of MDSubprogram nodes
Check operands of `MDSubprogram`s in the verifier, and update the
accessors and factory functions to use more specific types.

There were a lot of broken testcases, which I fixed in r233466.  If you
have out-of-tree tests for debug info, you probably need similar changes
to the ones I made there.

llvm-svn: 233559
2015-03-30 16:19:15 +00:00
Duncan P. N. Exon Smith 53855f05d3 Verifier: Check operands of MDType subclasses and MDCompileUnit
Add verify checks for `MDType` subclasses and for `MDCompileUnit`.
These new checks don't yet incorporate everything from `Verify()`, but
at least they sanity check the operands.  Also downcast accessors as
possible.

A lot of these accessors can't be downcast as far as we'd like because
of arrays of typed objects (stored in a generic `MDTuple`) and
`MDString`-based type references.  Eventually I'll port over `DIRef<>`
and `DITypedArray<>` from `DebugInfo.h` to clean those up as well.

Updated bitrotted testcases separately in r233415 and r233443 to reduce
churn on the off-chance this needs to be reverted.

llvm-svn: 233446
2015-03-27 23:05:04 +00:00
Duncan P. N. Exon Smith 3d2afaa29e Verifier: Check fields of MDVariable subclasses
Check fields from `MDLocalVariable` and `MDGlobalVariable` and change
the accessors to downcast to the right types.  `getType()` still returns
`Metadata*` since it could be an `MDString`-based reference.

Since local variables require non-null scopes, I also updated `LLParser`
to require a `scope:` field.

A number of testcases had grown bitrot and started failing with this
patch; I committed them separately in r233349.  If I just broke your
out-of-tree testcases, you're probably hitting similar problems (so have
a look there).

llvm-svn: 233389
2015-03-27 17:29:58 +00:00
Duncan P. N. Exon Smith 264899823f Verifier: Check accessors of MDLocation
Check accessors of `MDLocation`, and change them to `cast<>` down to the
right types.  Also add type-safe factory functions.

All the callers that handle broken code need to use the new versions of
the accessors (`getRawScope()` instead of `getScope()`) that still
return `Metadata*`.  This is also necessary for things like
`MDNodeKeyImpl<MDLocation>` (in LLVMContextImpl.h) that need to unique
the nodes when their operands might still be forward references of the
wrong type.

In the `Value` hierarchy, consumers that handle broken code use
`getOperand()` directly.  However, debug info nodes have a ton of
operands, and their order (even their existence) isn't stable yet.  It's
safer and more maintainable to add an explicit "raw" accessor on the
class itself.

llvm-svn: 233322
2015-03-26 22:05:04 +00:00
Duncan P. N. Exon Smith 3d510665e9 AsmWriter: Handle broken metadata nodes
Print out temporary `MDNode`s so we don't crash in the verifier (or
during `dump()` output).

llvm-svn: 232417
2015-03-16 21:21:10 +00:00
Duncan P. N. Exon Smith d6d70e753d IR: Make Metadata::print() reliable and useful
Replumb the `AsmWriter` so that `Metadata::print()` is generally useful.
(Similarly change `Metadata::printAsOperand()`.)

- `SlotTracker` now has a mode where all metadata will be correctly
  numbered when initializing a `Module`.  Normally, `Metadata` only
  referenced from within `Function`s gets numbered when the `Function`
  is incorporated.
- `Metadata::print()` and `Metadata::printAsOperand()` (and
  `Metadata::dump()`) now take an optional `Module` argument.  When
  provided, `SlotTracker` is initialized with the new mode, and the
  numbering will be complete and consistent for all calls to `print()`.
- `Value::print()` uses the new `SlotTracker` mode when printing
  intrinsics with `MDNode` operands, `MetadataAsValue` operands, or the
  bodies of functions.  Thus, metadata numbering will be consistent
  between calls to `Metadata::print()` and `Value::print()`.
- `Metadata::print()` (and `Metadata::dump()`) now print the full
  definition of `MDNode`s:

    !5 = !{!6, !"abc", !7}

  This matches behaviour for `Value::print()`, which includes the name
  of instructions.
- Updated call sites in `Verifier` to call `print()` instead of
  `printAsOperand()`.

All this, so that `Verifier` can print out useful failure messages that
involve `Metadata` for PR22777.

Note that `Metadata::printAsOperand()` previously took an optional
`bool` and `Module` operand.  The former was cargo-culted from
`Value::printAsOperand()` and wasn't doing anything useful.  The latter
didn't give consistent results (without the new `SlotTracker` mode).

llvm-svn: 232275
2015-03-14 20:19:36 +00:00
Duncan P. N. Exon Smith b353849c9e IR: Add missing API to specialized metadata nodes
Add the final bits of API that `DIBuilder` needs before the new nodes
can be moved into place.

  - Add `MDType::clone()` and `MDType::setFlags()` to support
    `DIBuilder::createTypeWithFlags()`.
  - Add `MDBasicType::get()` overload that just requires a tag and a
    name, as a convenience for `DIBuilder::createUnspecifiedType()`.
  - Add `MDLocalVariable::withInline()` and
    `MDLocalVariable::withoutInline()` to support
    `llvm::createInlinedVariable()` and
    `llvm::cleanseInlinedVariable()`.

(Somehow these got lost inside the "move into place" patch I'm about to
commit -- better to commit separately!)

llvm-svn: 231079
2015-03-03 16:45:34 +00:00
Duncan P. N. Exon Smith 2c6a0a905c IR: Specialize MDScope::getFile() for MDFile
Fix `MDScope::getFile()` so that it correctly returns a valid `MDFile`
even when it's an instance of `MDFile`.  This logic is necessary because
of r230057.  I'm working on moving the new hierarchy into place
out-of-tree (on track to commit Monday morning, BTW), and this was
exposed by a few failing tests.

llvm-svn: 230871
2015-02-28 21:47:02 +00:00
Duncan P. N. Exon Smith 738889f752 IR: Drop newline from AssemblyWriter::printMDNodeBody()
Remove a newline from `AssemblyWriter::printMDNodeBody()`, and add one
to `AssemblyWriter::writeMDNode()`.  NFCI for assembly output.

However, this drops an inconsistent newline from `Metadata::print()`
when `this` is an `MDNode`.  Now the newline added by `Metadata::dump()`
won't look so verbose.

llvm-svn: 230565
2015-02-25 22:46:38 +00:00
Duncan P. N. Exon Smith d34db1716e IR: Fix MDType fields from unsigned to uint64_t
When trying to match the current schema with the new debug info
hierarchy, I downgraded `SizeInBits`, `AlignInBits` and `OffsetInBits`
to 32-bits (oops!).  Caught this while testing my upgrade script to move
the hierarchy into place.  Bump it back up to 64-bits and update tests.

llvm-svn: 229933
2015-02-19 23:56:07 +00:00
Duncan P. N. Exon Smith a9f0a8d325 IR: Add missing null operand to MDSubroutineType
Add missing `nullptr` from `MDSubroutineType`'s operands for
`MDCompositeTypeBase::getIdentifier()` (and add tests for all the other
unused fields).  This highlights just how crazy it is that
`MDSubroutineType` inherits from `MDCompositeTypeBase`.

llvm-svn: 229926
2015-02-19 23:25:21 +00:00
Duncan P. N. Exon Smith 3d62bbacb1 IR: Drop scope from MDTemplateParameter
Follow-up to r229740, which removed `DITemplate*::getContext()` after my
upgrade script revealed that scopes are always `nullptr` for template
parameters.  This is the other shoe: drop `scope:` from
`MDTemplateParameter` and its two subclasses.  (Note: a bitcode upgrade
would be pointless, since the hierarchy hasn't been moved into place.)

llvm-svn: 229791
2015-02-19 00:37:21 +00:00
Duncan P. N. Exon Smith 5c9a17732b IR: Allow MDSubrange to have 'count: -1'
It turns out that `count: -1` is a special value indicating an empty
array, such as `Values` in:

    struct T {
      unsigned Count;
      int Values[];
    };

Handle it.

llvm-svn: 229769
2015-02-18 23:17:51 +00:00
Duncan P. N. Exon Smith f51e00dfd6 IR: Add MDCompositeTypeBase::replace*()
Add `replaceElements()`, `replaceVTableHolder()`, and
`replaceTemplateParams()` to `MDCompositeTypeBase`.  Included an
assertion in `replaceElements()` to match the one in
`DICompositeType::replaceArrays()`.

llvm-svn: 229744
2015-02-18 20:47:52 +00:00
Duncan P. N. Exon Smith 94bbbf0dee IR: Add MDCompileUnit::replace*()
Add `MDCompileUnit::replaceGlobalVariables()` and
`MDCompileUnit::replaceSubprograms()`.

llvm-svn: 229743
2015-02-18 20:36:09 +00:00
Duncan P. N. Exon Smith df52349bb0 IR: Add MDSubprogram::replaceFunction()
llvm-svn: 229742
2015-02-18 20:32:57 +00:00
Duncan P. N. Exon Smith 6873feaa2c IR: Add missing clone() overloads
Add missing specialized node overloads for `MDNode::clone()` (they were
on most of the node types already, but missing from the others).
`MDNode::clone()` returns `TempMDNode` (`std::unique_ptr<MDNode,...>`),
while `TempMDSubrange::clone()` (for example) returns the more
convenient `TempMDSubrange` (`std::unique_ptr<TempMDSubrange,...>`).

llvm-svn: 229579
2015-02-17 23:10:13 +00:00
Duncan P. N. Exon Smith 193a4fdafd IR: Add MDExpression::ExprOperand
Port `DIExpression::Operand` over to `MDExpression::ExprOperand`.  The
logic is needed directly in `MDExpression` to support printing in
assembly.

llvm-svn: 229002
2015-02-13 01:07:46 +00:00
Duncan P. N. Exon Smith 4ee4a98eaa IR: Add MDNode::replaceWithPermanent()
Add new API for converting temporaries that may self-reference.
Self-referencing nodes are not allowed to be uniqued, so sending them
into `replaceWithUniqued()` is dangerous (and this commit adds
assertions that prevent it).

`replaceWithPermanent()` has similar semantics to `get()` followed by
calls to `replaceOperandWith()`.  In particular, if there's a
self-reference, it returns a distinct node; otherwise, it returns a
uniqued one.  Like `replaceWithUniqued()` and `replaceWithDistinct()`
(well, it calls out to them) it mutates the temporary node in place if
possible, only calling `replaceAllUsesWith()` on a uniquing collision.

llvm-svn: 228726
2015-02-10 19:13:46 +00:00
Duncan P. N. Exon Smith bd33d375f0 IR: Remove unnecessary fields from MDTemplateParameter
I noticed this fields were never used in r228607, but I neglected to
propagate that into `MDTemplateParameter` until now.  This really should
have been done before commit in r228640; sorry for the churn.

llvm-svn: 228652
2015-02-10 01:59:57 +00:00
Duncan P. N. Exon Smith dddc537cc0 IR: Add accessors to MDExpression
Add some accessors to `MDExpression`.

llvm-svn: 228648
2015-02-10 01:36:46 +00:00
Duncan P. N. Exon Smith 01fc176977 IR: Add specialized debug info metadata nodes
Add specialized debug info metadata nodes that match the `DIDescriptor`
wrappers (used by `DIBuilder`) closely.  Assembly and bitcode support to
follow soon (it'll mostly just be obvious), but this sketches in today's
schema.  This is the first big commit (well, the only *big* one aside
from the testcase changes that'll come when I move this into place) for
PR22464.

I've marked a bunch of obvious changes as `TODO`s in the source; I plan
to make those changes promptly after this hierarchy is moved underneath
`DIDescriptor`, but for now I'm aiming mostly to match the status quo.

llvm-svn: 228640
2015-02-10 00:52:32 +00:00
Duncan P. N. Exon Smith af677ebb41 IR: Allow 32-bits for lines in debug location
Remove unnecessary restriction of 24-bits for line numbers in
`MDLocation`.

The rest of the debug info schema (with the exception of local
variables) uses 32-bits for line numbers.  As I introduce the
specialized nodes, it makes sense to canonicalize on one size or the
other.

llvm-svn: 228455
2015-02-06 22:50:13 +00:00
Duncan P. N. Exon Smith d9901ff586 IR: Split out DebugInfoMetadata.h, NFC
Move debug-info-centred `Metadata` subclasses into their own
header/source file.  A couple of private template functions are needed
from both `Metadata.cpp` and `DebugInfoMetadata.cpp`, so I've moved them
to `lib/IR/MetadataImpl.h`.

llvm-svn: 227835
2015-02-02 18:53:21 +00:00
Duncan P. N. Exon Smith 71db64258d Fix some file headers, NFC
llvm-svn: 227826
2015-02-02 18:20:15 +00:00
Duncan P. N. Exon Smith 68ab023ef7 IR: Change GenericDwarfNode::getHeader() to StringRef
Simplify the API to use a `StringRef` directly rather than exposing the
`MDString` bits underneath.

llvm-svn: 226876
2015-01-22 23:10:55 +00:00
Duncan P. N. Exon Smith e8b5e49ffd IR: DwarfNode => DebugNode, NFC
These things are potentially used for non-DWARF data (see the discussion
in PR22235), so take the `Dwarf` out of the name.  Since the new name
gives fewer clues, update the doxygen to properly describe what they
are.

llvm-svn: 226874
2015-01-22 22:47:44 +00:00
Duncan P. N. Exon Smith 8d536973a2 IR: Update references to temporaries before deleting
During `MDNode::deleteTemporary()`, call `replaceAllUsesWith(nullptr)`
to update all tracking references to `nullptr`.

This fixes PR22280, where inverted destruction order between tracking
references and the temporaries themselves caused a use-after-free in
`LLParser`.

An alternative fix would be to add an assertion that there are no users,
and continue to fix inverted destruction order in clients (like
`LLParser`), but instead I decided to make getting-teardown-right easy.
(If someone disagrees let me know.)

llvm-svn: 226866
2015-01-22 21:36:45 +00:00
Duncan P. N. Exon Smith 2da09e4408 IR: Canonicalize GenericDwarfNode empty headers to null
llvm-svn: 226532
2015-01-20 00:58:46 +00:00
Duncan P. N. Exon Smith fed199a758 IR: Introduce GenericDwarfNode
As part of PR22235, introduce `DwarfNode` and `GenericDwarfNode`.  The
former is a metadata node with a DWARF tag.  The latter matches our
current (generic) schema of a header with string (and stringified
integer) data and an arbitrary number of operands.

This doesn't move it into place yet; that change will require a large
number of testcase updates.

llvm-svn: 226529
2015-01-20 00:01:43 +00:00
Duncan P. N. Exon Smith e33530909d IR: Allow temporary nodes to become uniqued or distinct
Add `MDNode::replaceWithUniqued()` and `MDNode::replaceWithDistinct()`,
which mutate temporary nodes to become uniqued or distinct.  On uniquing
collisions, the unique version is returned and the node is deleted.

This takes advantage of temporary nodes being folded back in, and should
let me clean up some awkward logic in `MapMetadata()`.

llvm-svn: 226510
2015-01-19 22:24:52 +00:00
Duncan P. N. Exon Smith 7d82313bcd IR: Return unique_ptr from MDNode::getTemporary()
Change `MDTuple::getTemporary()` and `MDLocation::getTemporary()` to
return (effectively) `std::unique_ptr<T, MDNode::deleteTemporary>`, and
clean up call sites.  (For now, `DIBuilder` call sites just call
`release()` immediately.)

There's an accompanying change in each of clang and polly to use the new
API.

llvm-svn: 226504
2015-01-19 21:30:18 +00:00
Duncan P. N. Exon Smith 799e56a9ae IR: Add MDLocation::getTemporary()
llvm-svn: 226502
2015-01-19 20:37:44 +00:00
Duncan P. N. Exon Smith 946fdcc50c IR: Remove MDNodeFwdDecl
Remove `MDNodeFwdDecl` (as promised in r226481).  Aside from API
changes, there's no real functionality change here.
`MDNode::getTemporary()` now forwards to `MDTuple::getTemporary()`,
which returns a tuple with `isTemporary()` equal to true.

The main point is that we can now add temporaries of other `MDNode`
subclasses, needed for PR22235 (I introduced `MDNodeFwdDecl` in the
first place because I didn't recognize this need, and thought they were
only needed to handle forward references).

A few things left out of (or highlighted by) this commit:

  - I've had to remove the (few) uses of `std::unique_ptr<>` to deal
    with temporaries, since the destructor is no longer public.
    `getTemporary()` should probably return the equivalent of
    `std::unique_ptr<T, MDNode::deleteTemporary>`.
  - `MDLocation::getTemporary()` doesn't exist yet (worse, it actually
    does exist, but does the wrong thing: `MDNode::getTemporary()` is
    inherited and returns an `MDTuple`).
  - `MDNode` now only has one subclass, `UniquableMDNode`, and the
    distinction between them is actually somewhat confusing.

I'll fix those up next.

llvm-svn: 226501
2015-01-19 20:36:39 +00:00
Duncan P. N. Exon Smith 2711ca7c28 IR: Store RAUW support and Context in the same pointer, NFC
Add an `LLVMContext &` to `ReplaceableMetadataImpl`, create a class that
either holds a reference to an `LLVMContext` or owns a
`ReplaceableMetadataImpl`, and use the new class in `MDNode`.

  - This saves a pointer in `UniquableMDNode` at the cost of a pointer
    in `ValueAsMetadata` (which didn't used to store the `LLVMContext`).
    There are far more of the former.
  - Unifies RAUW support between `MDNodeFwdDecl` (which is going away,
    see r226481) and `UniquableMDNode`.

llvm-svn: 226484
2015-01-19 19:02:06 +00:00