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
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
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
No change in this commit, but clang was changed to also produce trivial comdats when
needed.
Original message:
Don't create new comdats in CodeGen.
This patch stops the implicit creation of comdats during codegen.
Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226467 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r226173, adding r226038 back.
No change in this commit, but clang was changed to also produce trivial comdats for
costructors, destructors and vtables when needed.
Original message:
Don't create new comdats in CodeGen.
This patch stops the implicit creation of comdats during codegen.
Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226242 91177308-0d34-0410-b5e6-96231b3b80d8
This patch stops the implicit creation of comdats during codegen.
Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226038 91177308-0d34-0410-b5e6-96231b3b80d8
This adds assembly and bitcode support for `MDLocation`. The assembly
side is rather big, since this is the first `MDNode` subclass (that
isn't `MDTuple`). Part of PR21433.
(If you're wondering where the mountains of testcase updates are, we
don't need them until I update `DILocation` and `DebugLoc` to actually
use this class.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225830 91177308-0d34-0410-b5e6-96231b3b80d8
Refactor logic so that we know up-front whether to open a block and
whether we need an MDString abbreviation.
This is almost NFC, but will start emitting `MDString` abbreviations
when the first record is not an `MDString`.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225712 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r225498 (but leaves r225499, which was a worthy
cleanup).
My plan was to change `DEBUG_LOC` to store the `MDNode` directly rather
than its operands (patch was to go out this morning), but on reflection
it's not clear that it's strictly better. (I had missed that the
current code is unlikely to emit the `MDNode` at all.)
Conflicts:
lib/Bitcode/Reader/BitcodeReader.cpp (due to r225499)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225531 91177308-0d34-0410-b5e6-96231b3b80d8
Propagate whether `MDNode`s are 'distinct' through the other types of IR
(assembly and bitcode). This adds the `distinct` keyword to assembly.
Currently, no one actually calls `MDNode::getDistinct()`, so these nodes
only get created for:
- self-references, which are never uniqued, and
- nodes whose operands are replaced that hit a uniquing collision.
The concept of distinct nodes is still not quite first-class, since
distinct-ness doesn't yet survive across `MapMetadata()`.
Part of PR22111.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225474 91177308-0d34-0410-b5e6-96231b3b80d8
`MDString`s can have arbitrary characters in them. Prevent an assertion
that fired in `BitcodeWriter` because of sign extension by copying the
characters into the record as `unsigned char`s.
Based on a patch by Keno Fischer; fixes PR21882.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224077 91177308-0d34-0410-b5e6-96231b3b80d8
This reflects the typelessness of `Metadata` in the bitcode format,
removing types from all metadata operands.
`METADATA_VALUE` represents a `ValueAsMetadata`, and always has two
fields: the type and the value.
`METADATA_NODE` represents an `MDNode`, and unlike `METADATA_OLD_NODE`,
doesn't store types. It stores operands at their ID+1 so that `0` can
reference `nullptr` operands.
Part of PR21532.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224073 91177308-0d34-0410-b5e6-96231b3b80d8
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
Patch by Ben Gamari!
This redefines the `prefix` attribute introduced previously and
introduces a `prologue` attribute. There are a two primary usecases
that these attributes aim to serve,
1. Function prologue sigils
2. Function hot-patching: Enable the user to insert `nop` operations
at the beginning of the function which can later be safely replaced
with a call to some instrumentation facility
3. Runtime metadata: Allow a compiler to insert data for use by the
runtime during execution. GHC is one example of a compiler that
needs this functionality for its tables-next-to-code functionality.
Previously `prefix` served cases (1) and (2) quite well by allowing the user
to introduce arbitrary data at the entrypoint but before the function
body. Case (3), however, was poorly handled by this approach as it
required that prefix data was valid executable code.
Here we redefine the notion of prefix data to instead be data which
occurs immediately before the function entrypoint (i.e. the symbol
address). Since prefix data now occurs before the function entrypoint,
there is no need for the data to be valid code.
The previous notion of prefix data now goes under the name "prologue
data" to emphasize its duality with the function epilogue.
The intention here is to handle cases (1) and (2) with prologue data and
case (3) with prefix data.
References
----------
This idea arose out of discussions[1] with Reid Kleckner in response to a
proposal to introduce the notion of symbol offsets to enable handling of
case (3).
[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073235.html
Test Plan: testsuite
Differential Revision: http://reviews.llvm.org/D6454
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223189 91177308-0d34-0410-b5e6-96231b3b80d8
Instead, we're going to separate metadata from the Value hierarchy. See
PR21532.
This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221711 91177308-0d34-0410-b5e6-96231b3b80d8
Change `Instruction::getAllMetadataOtherThanDebugLoc()` from a vector of
`MDNode` to one of `Value`. Part of PR21433.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221167 91177308-0d34-0410-b5e6-96231b3b80d8
1. Use const with autos.
2. Don't bother with explicit const in cast ops because they do it automagically.
Thanks, David B. / Aaron B. / Reid K.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219817 91177308-0d34-0410-b5e6-96231b3b80d8
Predict and serialize use-list order in bitcode. This makes the option
`-preserve-bc-use-list-order` work *most* of the time, but this is still
experimental.
- Builds a full value-table up front in the writer, sets up a list of
use-list orders to write out, and discards the table. This is a
simpler first step than determining the order from the various
overlapping IDs of values on-the-fly.
- The shuffles stored in the use-list order list have an unnecessarily
large memory footprint.
- `blockaddress` expressions cause functions to be materialized
out-of-order. For now I've ignored this problem, so use-list orders
will be wrong for constants used by functions that have block
addresses taken. There are a couple of ways to fix this, but I
don't have a concrete plan yet.
- When materializing functions lazily, the use-lists for constants
will not be correct. This use case is out of scope: what should the
use-list order be, if it's incomplete?
This is part of PR5680.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214125 91177308-0d34-0410-b5e6-96231b3b80d8
Add a -verify-use-list-order pass, which shuffles use-list order, writes
to bitcode, reads back, and verifies that the (shuffled) order matches.
- The utility functions live in lib/IR/UseListOrder.cpp.
- Moved (and renamed) the command-line option to enable writing
use-lists, so that this pass can return early if the use-list orders
aren't being serialized.
It's not clear that this pass is the right direction long-term (perhaps
a separate tool instead?), but short-term it's a great way to test the
use-list order prototype. I've added an XFAIL-ed testcase that I'm
hoping to get working pretty quickly.
This is part of PR5680.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213945 91177308-0d34-0410-b5e6-96231b3b80d8
This attribute indicates that the parameter or return pointer is
dereferenceable. Practically speaking, loads from such a pointer within the
associated byte range are safe to speculatively execute. Such pointer
parameters are common in source languages (C++ references, for example).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213385 91177308-0d34-0410-b5e6-96231b3b80d8
Currently the only kind of integer IR attributes that we have are alignment
attributes, and so the attribute kind that takes an integer parameter is called
AlignAttr, but that will change (we'll soon be adding a dereferenceable
attribute that also takes an integer value). Accordingly, rename AlignAttribute
to IntAttribute (class names, enums, etc.).
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213352 91177308-0d34-0410-b5e6-96231b3b80d8
This was an oversight in the original support. As it is, I stuffed this
bit into the alignment. The alignment is stored in log2 form, so it
doesn't need more than 5 bits, given that Value::MaximumAlignment is 1
<< 29.
Reviewers: nicholas
Differential Revision: http://reviews.llvm.org/D3943
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213118 91177308-0d34-0410-b5e6-96231b3b80d8
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.
COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.
This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.
Differential Revision: http://reviews.llvm.org/D4178
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211920 91177308-0d34-0410-b5e6-96231b3b80d8
This commit adds a weak variant of the cmpxchg operation, as described
in C++11. A cmpxchg instruction with this modifier is permitted to
fail to store, even if the comparison indicated it should.
As a result, cmpxchg instructions must return a flag indicating
success in addition to their original iN value loaded. Thus, for
uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The
second flag is 1 when the store succeeded.
At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been
added as the natural representation for the new cmpxchg instructions.
It is a strong cmpxchg.
By default this gets Expanded to the existing ATOMIC_CMP_SWAP during
Legalization, so existing backends should see no change in behaviour.
If they wish to deal with the enhanced node instead, they can call
setOperationAction on it. Beware: as a node with 2 results, it cannot
be selected from TableGen.
Currently, no use is made of the extra information provided in this
patch. Test updates are almost entirely adapting the input IR to the
new scheme.
Summary for out of tree users:
------------------------------
+ Legacy Bitcode files are upgraded during read.
+ Legacy assembly IR files will be invalid.
+ Front-ends must adapt to different type for "cmpxchg".
+ Backends should be unaffected by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210903 91177308-0d34-0410-b5e6-96231b3b80d8
Alias with unnamed_addr were in a strange state. It is stored in GlobalValue,
the language reference talks about "unnamed_addr aliases" but the verifier
was rejecting them.
It seems natural to allow unnamed_addr in aliases:
* It is a property of how it is accessed, not of the data itself.
* It is perfectly possible to write code that depends on the address
of an alias.
This patch then makes unname_addr legal for aliases. One side effect is that
the syntax changes for a corner case: In globals, unnamed_addr is now printed
before the address space.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210302 91177308-0d34-0410-b5e6-96231b3b80d8
It includes a pass that rewrites all indirect calls to jumptable functions to pass through these tables.
This also adds backend support for generating the jump-instruction tables on ARM and X86.
Note that since the jumptable attribute creates a second function pointer for a
function, any function marked with jumptable must also be marked with unnamed_addr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210280 91177308-0d34-0410-b5e6-96231b3b80d8
This matches gcc's behavior. It also seems natural given that aliases
contain other properties that govern how it is accessed (linkage,
visibility, dll storage).
Clang still has to be updated to expose this feature to C.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209759 91177308-0d34-0410-b5e6-96231b3b80d8
