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
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
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
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
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
Change `MDNode::isDistinct()` to only apply to 'distinct' nodes (not
temporaries), and introduce `MDNode::isUniqued()` and
`MDNode::isTemporary()` for the other two possibilities.
llvm-svn: 226482
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).
llvm-svn: 226029
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.
llvm-svn: 225974
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.
llvm-svn: 225824
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).
llvm-svn: 225745
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.
llvm-svn: 225742
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.
llvm-svn: 225406
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.
llvm-svn: 225401
Now that `LLVMContextImpl` can call `MDNode::dropAllReferences()` to
prevent teardown madness, stop dropping uniquing just because an operand
drops to null.
Part of PR21532.
llvm-svn: 225223
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}
llvm-svn: 224325
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`.
llvm-svn: 224146
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.)
llvm-svn: 223802
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.
llvm-svn: 223618
Apparently `MDNode` uniquing used to be optional. I suppose the
configure flag must have disappeared at some point. Change the test so
it actually tests uniquing, and remove the check for
`ENABLE_MDNODE_UNIQUING`.
llvm-svn: 223617
Move the test for this class into the IR unittests as well.
This uncovers that ValueMap too is in the IR library. Ironically, the
unittest for ValueMap is useless in the Support library (honestly, so
was the ValueHandle test) and so it already lives in the IR unittests.
Mmmm, tasty layering.
llvm-svn: 202821
Duncan P. N. Exon Smith