Commit Graph

181 Commits

Author SHA1 Message Date
Chandler Carruth
417c5c172c [PM] Remove the old 'PassManager.h' header file at the top level of
LLVM's include tree and the use of using declarations to hide the
'legacy' namespace for the old pass manager.

This undoes the primary modules-hostile change I made to keep
out-of-tree targets building. I sent an email inquiring about whether
this would be reasonable to do at this phase and people seemed fine with
it, so making it a reality. This should allow us to start bootstrapping
with modules to a certain extent along with making it easier to mix and
match headers in general.

The updates to any code for users of LLVM are very mechanical. Switch
from including "llvm/PassManager.h" to "llvm/IR/LegacyPassManager.h".
Qualify the types which now produce compile errors with "legacy::". The
most common ones are "PassManager", "PassManagerBase", and
"FunctionPassManager".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229094 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 10:01:29 +00:00
Duncan P. N. Exon Smith
7473485c0f IR: Add MDExpression::ExprOperand
Port `DIExpression::Operand` over to `MDExpression::ExprOperand`.  The
logic is needed directly in `MDExpression` to support printing in
assembly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229002 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:07:46 +00:00
Duncan P. N. Exon Smith
027898a77a 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228726 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 19:13:46 +00:00
Duncan P. N. Exon Smith
3740ae4600 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228652 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 01:59:57 +00:00
Duncan P. N. Exon Smith
db7dea0e2e IR: Add accessors to MDExpression
Add some accessors to `MDExpression`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228648 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 01:36:46 +00:00
Duncan P. N. Exon Smith
14fcfef23b 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228640 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 00:52:32 +00:00
Duncan P. N. Exon Smith
8713d99a25 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228455 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-06 22:50:13 +00:00
Duncan P. N. Exon Smith
ca8d3bf8af 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`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227835 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-02 18:53:21 +00:00
Duncan P. N. Exon Smith
0784a4dabb Fix some file headers, NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227826 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-02 18:20:15 +00:00
Duncan P. N. Exon Smith
a791aea5ae IR: Change GenericDwarfNode::getHeader() to StringRef
Simplify the API to use a `StringRef` directly rather than exposing the
`MDString` bits underneath.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226876 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 23:10:55 +00:00
Duncan P. N. Exon Smith
cee1699e9f 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226874 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 22:47:44 +00:00
Duncan P. N. Exon Smith
003346177c 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.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226866 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 21:36:45 +00:00
Adrian Prantl
bc1819e62e simplify expression
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226701 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-21 21:23:35 +00:00
Adrian Prantl
8737be85f6 Fix a compile issue on MSVC and call finalize().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226694 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-21 19:25:35 +00:00
Adrian Prantl
9dc47c0c4a Let subprograms with instructions without parent scopes fail the
verification. Tested via a unit test.

Follow-up to r226616.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226684 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-21 18:32:56 +00:00
Duncan P. N. Exon Smith
62475afaf2 IR: Canonicalize GenericDwarfNode empty headers to null
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226532 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-20 00:58:46 +00:00
Duncan P. N. Exon Smith
0a9f921686 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226529 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-20 00:01:43 +00:00
Duncan P. N. Exon Smith
37c7ccc40c 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()`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226510 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 22:24:52 +00:00
Duncan P. N. Exon Smith
f9eaea701d 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226504 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 21:30:18 +00:00
Duncan P. N. Exon Smith
a7852bfa47 IR: Add MDLocation::getTemporary()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226502 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 20:37:44 +00:00
Duncan P. N. Exon Smith
8ec0aee3b4 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226501 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 20:36:39 +00:00
Duncan P. N. Exon Smith
641414a6c0 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`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226484 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 19:02:06 +00:00
Duncan P. N. Exon Smith
1d72e18caa IR: Add isUniqued() and isTemporary()
Change `MDNode::isDistinct()` to only apply to 'distinct' nodes (not
temporaries), and introduce `MDNode::isUniqued()` and
`MDNode::isTemporary()` for the other two possibilities.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226482 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 18:45:35 +00:00
Chandler Carruth
de5df29556 [PM] Split the LoopInfo object apart from the legacy pass, creating
a LoopInfoWrapperPass to wire the object up to the legacy pass manager.

This switches all the clients of LoopInfo over and paves the way to port
LoopInfo to the new pass manager. No functionality change is intended
with this iteration.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226373 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-17 14:16:18 +00:00
Duncan P. N. Exon Smith
fb7514fccb IR: Allow 16-bits for column info
Raise the limit for column information from 8 bits to 16 bits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226291 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-16 17:33:08 +00:00
Duncan P. N. Exon Smith
9e4a11f46c IR: Fix a use-after-free in RAUW
Happened pretty commonly during `LLVMContext` teardown when `clang -g`
hit an error.  This fixes the use-after-free.  Next I'll clean up
teardown so that it's not RAUW'ing when metadata-tracked values are
deleted (only really causes a problem if the graph is mid-construction
when teardown starts, but it's still unnecessary work).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226029 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 19:56:10 +00:00
Chandler Carruth
1b279144ec [cleanup] Re-sort all the #include lines in LLVM using
utils/sort_includes.py.

I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225974 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 11:23:27 +00:00
Duncan P. N. Exon Smith
d640962656 IR: Add MDLocation class
Add a new subclass of `UniquableMDNode`, `MDLocation`.  This will be the
IR version of `DebugLoc` and `DILocation`.  The goal is to rename this
to `DILocation` once the IR classes supersede the `DI`-prefixed
wrappers.

This isn't used anywhere yet.  Part of PR21433.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225824 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 20:44:56 +00:00
NAKAMURA Takumi
16a6d38e01 IR/MetadataTest.cpp: Appease msc17 to avoid initializer list.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225775 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 08:13:46 +00:00
Duncan P. N. Exon Smith
6e4bbf0390 IR: Use unique_ptr, NFC
Use `std::unique_ptr<>`, as suggested by David Blaikie.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225749 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 00:57:27 +00:00
Duncan P. N. Exon Smith
698be08c84 IR: Remove an invalid assertion when replacing resolved operands
This adds back the testcase from r225738, and adds to it.  Looks like we
need both sides for now (the assertion was incorrect both ways, and
although it seemed reasonable (when written correctly) it wasn't
particularly important).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225745 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 00:46:34 +00:00
Duncan P. N. Exon Smith
47952358ce Revert "IR: Fix an inverted assertion when replacing resolved operands"
This reverts commit r225738.  Maybe the assertion is just plain wrong,
but this version fails on WAY more bots.  I'll make sure both ways work
in a follow-up but I want to get bots green in the meantime.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225742 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 00:34:21 +00:00
Duncan P. N. Exon Smith
4fef722974 IR: Fix an inverted assertion when replacing resolved operands
Add a unit test, since this bug was only exposed by clang tests.  Thanks
to Rafael for tracking this down!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225738 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 00:10:38 +00:00
Duncan P. N. Exon Smith
5e3ba22b3a IR: Fix unit test memory leak reported by ASan
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/603/steps/check-llvm%20asan/logs/stdio

Thanks Alexey for pointing me to this!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225721 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:46:15 +00:00
Duncan P. N. Exon Smith
45db33d634 IR: Make MDNodeFwdDecl destructor public
Now that the leak detector is gone, anyone can call this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225689 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 20:19:54 +00:00
Duncan P. N. Exon Smith
728315adf4 IR: Add test for handleChangedOperand() recursion
Turns out this can happen.  Remove the `FIXME` and add a testcase that
crashes without the extra logic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225657 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 19:22:04 +00:00
Duncan P. N. Exon Smith
28184c10c9 IR: Make temporary nodes distinct
Change the return of `MDNode::isDistinct()` for `MDNode::getTemporary()`
to `true`.  They aren't uniqued.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225646 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 18:41:26 +00:00
Duncan P. N. Exon Smith
727176d00e IR: Add MDNode::getDistinct()
Allow distinct `MDNode`s to be explicitly created.  There's no way (yet)
of representing their distinctness in assembly/bitcode, however, so this
still isn't first-class.

Part of PR22111.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225406 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 22:24:46 +00:00
Duncan P. N. Exon Smith
ee06e126b7 IR: Add MDNode::isDistinct()
Add API to indicate whether an `MDNode` is distinct.  A distinct node is
not stored in the MDNode uniquing tables, and will never be returned by
`MDNode::get()`.

Although distinct nodes are only currently created by uniquing
collisions (when operands change), PR22111 will allow these nodes to be
explicitly created.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225401 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 21:35:38 +00:00
Duncan P. N. Exon Smith
97d1c07c15 IR: Don't drop MDNode uniquing on null operands
Now that `LLVMContextImpl` can call `MDNode::dropAllReferences()` to
prevent teardown madness, stop dropping uniquing just because an operand
drops to null.

Part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225223 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-05 23:31:54 +00:00
Chandler Carruth
040ca449b2 [PM] Add names and debug logging for analysis passes to the new pass
manager.

This starts to allow us to test analyses more easily, but it's really
only the beginning. Some of the code here is still untestable without
manual changes to create analysis passes, but I wanted to factor it into
a small of chunks as possible.

Next up in order to be able to test things are, in no particular order:
- No-op analyses passes so we don't have to use real ones to exercise
  the pass maneger itself.
- Automatic way of generating dummy passes that require an analysis be
  run, including a variant that calls a 'print' method on a pass to make
  it even easier to print out the results of an analysis.
- Dummy passes that invalidate all analyses for their IR unit so we can
  test invalidation and re-runs.
- Automatic way to print each analysis pass as it is re-run.
- Automatic but optional verification of analysis passes everywhere
  possible.

I'm not claiming I'll get to all of these immediately, but that's what
is in the pipeline at some stage. I'm fleshing out exactly what I need
and what to prioritize by working on converting analyses and then trying
to test the conversion. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225162 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-05 12:21:44 +00:00
Chandler Carruth
b246acebf4 [PM] Switch the new pass manager to use a reference-based API for IR
units.

This was debated back and forth a bunch, but using references is now
clearly cleaner. Of all the code written using pointers thus far, in
only one place did it really make more sense to have a pointer. In most
cases, this just removes immediate dereferencing from the code. I think
it is much better to get errors on null IR units earlier, potentially
at compile time, than to delay it.

Most notably, the legacy pass manager uses references for its routines
and so as more and more code works with both, the use of pointers was
likely to become really annoying. I noticed this when I ported the
domtree analysis over and wrote the entire thing with references only to
have it fail to compile. =/ It seemed better to switch now than to
delay. We can, of course, revisit this is we learn that references are
really problematic in the API.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225145 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-05 02:47:05 +00:00
Rafael Espindola
1871cba561 Fix a leak found by asan.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224773 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 17:20:23 +00:00
Rafael Espindola
ada5f24b5f The leak detector is dead, long live asan and valgrind.
In resent times asan and valgrind have found way more memory management bugs
in llvm than the special purpose leak detector.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224703 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-22 13:00:36 +00:00
Duncan P. N. Exon Smith
9e2c0f95fe Remove 'metadata' from comments
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224328 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 07:45:05 +00:00
Duncan P. N. Exon Smith
02a8d1bcfd IR: Stop printing 'metadata' in Metadata::print()
Stop printing `metadata` in `Metadata::print()` and
`Metadata::printAsOperand()`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224327 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 07:40:31 +00:00
Duncan P. N. Exon Smith
2ebd1efc08 IR: Make MDNode::dump() useful by adding addresses
It's horrible to inspect `MDNode`s in a debugger.  All of their operands
that are `MDNode`s get dumped as `<badref>`, since we can't assign
metadata slots in the context of a `Metadata::dump()`.  (Why not?  Why
not assign numbers lazily?  Because then each time you called `dump()`,
a given `MDNode` could have a different lazily assigned number.)

Fortunately, the C memory model gives us perfectly good identifiers for
`MDNode`.  Add pointer addresses to the dumps, transforming this:

    (lldb) e N->dump()
    !{i32 662302, i32 26, <badref>, null}

    (lldb) e ((MDNode*)N->getOperand(2))->dump()
    !{i32 4, !"foo"}

into:

    (lldb) e N->dump()
    !{i32 662302, i32 26, <0x100706ee0>, null}

    (lldb) e ((MDNode*)0x100706ee0)->dump()
    !{i32 4, !"foo"}

and this:

    (lldb) e N->dump()
    0x101200248 = !{<badref>, <badref>, <badref>, <badref>, <badref>}

    (lldb) e N->getOperand(0)
    (const llvm::MDOperand) $0 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(1)
    (const llvm::MDOperand) $1 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(2)
    (const llvm::MDOperand) $2 = {
      MD = 0x0000000101200058
    }
    (lldb) e N->getOperand(3)
    (const llvm::MDOperand) $3 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(4)
    (const llvm::MDOperand) $4 = {
      MD = 0x0000000101200058
    }
    (lldb) e ((MDNode*)0x00000001012004e0)->dump()
    !{}

    (lldb) e ((MDNode*)0x0000000101200058)->dump()
    !{null}

into:

    (lldb) e N->dump()
    !{<0x1012004e0>, <0x1012004e0>, <0x101200058>, <0x1012004e0>, <0x101200058>}

    (lldb) e ((MDNode*)0x1012004e0)->dump()
    !{}

    (lldb) e ((MDNode*)0x101200058)->dump()
    !{null}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224325 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 07:09:37 +00:00
Duncan P. N. Exon Smith
85cbe57fc5 IR: Don't track nullptr on metadata RAUW
The RAUW support in `Metadata` supports going to `nullptr` specifically
to handle values being deleted, causing `ValueAsMetadata` to be deleted.

Fix the case where the reference is from a `TrackingMDRef` (as opposed
to an `MDOperand` or a `MetadataAsValue`).

This is surprisingly rare -- metadata tracked by `TrackingMDRef` going
to null -- but it came up in an openSUSE bootstrap during inlining.  The
tracking ref was held by the `ValueMap` because it was referencing a
local, the basic block containing the local became dead after it had
been merged in, and when the local was deleted, the tracking ref
asserted in an `isa`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224146 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-12 19:24:33 +00:00
Duncan P. N. Exon Smith
dad20b2ae2 IR: Split Metadata from Value
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532.  Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.

I have a follow-up patch prepared for `clang`.  If this breaks other
sub-projects, I apologize in advance :(.  Help me compile it on Darwin
I'll try to fix it.  FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.

This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.

Here's a quick guide for updating your code:

  - `Metadata` is the root of a class hierarchy with three main classes:
    `MDNode`, `MDString`, and `ValueAsMetadata`.  It is distinct from
    the `Value` class hierarchy.  It is typeless -- i.e., instances do
    *not* have a `Type`.

  - `MDNode`'s operands are all `Metadata *` (instead of `Value *`).

  - `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
    replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.

    If you're referring solely to resolved `MDNode`s -- post graph
    construction -- just use `MDNode*`.

  - `MDNode` (and the rest of `Metadata`) have only limited support for
    `replaceAllUsesWith()`.

    As long as an `MDNode` is pointing at a forward declaration -- the
    result of `MDNode::getTemporary()` -- it maintains a side map of its
    uses and can RAUW itself.  Once the forward declarations are fully
    resolved RAUW support is dropped on the ground.  This means that
    uniquing collisions on changing operands cause nodes to become
    "distinct".  (This already happened fairly commonly, whenever an
    operand went to null.)

    If you're constructing complex (non self-reference) `MDNode` cycles,
    you need to call `MDNode::resolveCycles()` on each node (or on a
    top-level node that somehow references all of the nodes).  Also,
    don't do that.  Metadata cycles (and the RAUW machinery needed to
    construct them) are expensive.

  - An `MDNode` can only refer to a `Constant` through a bridge called
    `ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).

    As a side effect, accessing an operand of an `MDNode` that is known
    to be, e.g., `ConstantInt`, takes three steps: first, cast from
    `Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
    third, cast down to `ConstantInt`.

    The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
    metadata schema owners transition away from using `Constant`s when
    the type isn't important (and they don't care about referring to
    `GlobalValue`s).

    In the meantime, I've added transitional API to the `mdconst`
    namespace that matches semantics with the old code, in order to
    avoid adding the error-prone three-step equivalent to every call
    site.  If your old code was:

        MDNode *N = foo();
        bar(isa             <ConstantInt>(N->getOperand(0)));
        baz(cast            <ConstantInt>(N->getOperand(1)));
        bak(cast_or_null    <ConstantInt>(N->getOperand(2)));
        bat(dyn_cast        <ConstantInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));

    you can trivially match its semantics with:

        MDNode *N = foo();
        bar(mdconst::hasa               <ConstantInt>(N->getOperand(0)));
        baz(mdconst::extract            <ConstantInt>(N->getOperand(1)));
        bak(mdconst::extract_or_null    <ConstantInt>(N->getOperand(2)));
        bat(mdconst::dyn_extract        <ConstantInt>(N->getOperand(3)));
        bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));

    and when you transition your metadata schema to `MDInt`:

        MDNode *N = foo();
        bar(isa             <MDInt>(N->getOperand(0)));
        baz(cast            <MDInt>(N->getOperand(1)));
        bak(cast_or_null    <MDInt>(N->getOperand(2)));
        bat(dyn_cast        <MDInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));

  - A `CallInst` -- specifically, intrinsic instructions -- can refer to
    metadata through a bridge called `MetadataAsValue`.  This is a
    subclass of `Value` where `getType()->isMetadataTy()`.

    `MetadataAsValue` is the *only* class that can legally refer to a
    `LocalAsMetadata`, which is a bridged form of non-`Constant` values
    like `Argument` and `Instruction`.  It can also refer to any other
    `Metadata` subclass.

(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223802 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 18:38:53 +00:00
Duncan P. N. Exon Smith
7280d8ccce IR: Drop uniquing for self-referencing MDNodes
It doesn't make sense to unique self-referencing nodes.  Drop uniquing
for them.

Note that `MDNode::intersect()` occasionally returns self-referencing
nodes.  Previously these would be returned by `MDNode::get()`.  I'm not
convinced this was intended behaviour -- to me it seems it should return
a node whose only operand is the self-reference -- but I don't know much
about alias scopes so I'm preserving it for now.

This is part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223618 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-07 19:52:06 +00:00