The bitcode upgrade I added for DISubprogram in r266446 was based on the
assumption that the CU node for the subprogram was already materialized by the
time the DISubprogram is visited. This assumption may not hold true as future
versions of LLVM may decide to write out bitcode in a different order. This
patch corrects this by introducing a versioning bit next to the distinct flag to
unambiguously differentiate the new from the old record layouts.
Note for people stabilizing LLVM out-of-tree: This patch introduces a bitcode
incompatibility with llvm trunk revisions from r266446 — this commit. (But
D19987 will ensure that it degrades gracefully).
http://reviews.llvm.org/D20004
rdar://problem/26074194
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268816 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
With the removal of support for lazy parsing of combined index summary
records (e.g. r267344), we no longer need to include the summary record
bitcode offset in the VST entries for definitions. Change the combined
index format to be similar to the per-module index format in using value
ids to cross-reference from the summary record to the VST entry (rather
than the summary record bitcode offset to cross-reference in the other
direction).
The visible changes are:
1) Add the value id to the combined summary records
2) Remove the summary offset from the combined VST records, which has
the following effects:
- No longer need the VST_CODE_COMBINED_GVDEFENTRY record, as all
combined index VST entries now only contain the value id and
corresponding GUID.
- No longer have duplicate VST entries in the case where there are
multiple definitions of a symbol (e.g. weak/linkonce), as they all
have the same value id and GUID.
An implication of #2 above is that in order to hook up an alias to the
correct aliasee based on the value id of the aliasee recorded in the
combined index alias record, we need to scan the entries in the index
for that GUID to find the one from the same module (i.e. the case where
there are multiple entries for the aliasee). But the reader no longer
has to maintain a special map to hook up the alias/aliasee.
Reviewers: joker.eph
Subscribers: joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D19481
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267712 91177308-0d34-0410-b5e6-96231b3b80d8
There's hardly any functionality change here. Instead of calling
materializeMetadata on the first call to materialize(GlobalValue*), wait
until the first one that's actually going to do something. Noticed by
inspection; I don't have a concrete case where this makes a difference.
Added an assertion in materializeMetadata to be sure this (or a future
change) doesn't delay materializeMetadata after function-level metadata.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267345 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Remove the GlobalValueInfo and change the ModuleSummaryIndex to directly
reference summary objects. The info structure was there to support lazy
parsing of the combined index summary objects, which is no longer
needed and not supported.
Reviewers: joker.eph
Subscribers: joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D19462
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267344 91177308-0d34-0410-b5e6-96231b3b80d8
Add tests for some missing cases to bitcode upgrade in r267296.
- DICompositeType with an 'elements:' field, which will cause it to be
involved in a cycle after the upgrade.
- A DIDerivedType that references a class in 'extraData:'.
I updated test/Bitcode/dityperefs-3.8.ll with the missing cases and
regenerated test/Bitcode/dityperefs-3.8.ll.bc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267332 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
As discussed in D18298, some local globals can't
be renamed/promoted (because they have a section, or because
they are referenced from inline assembly).
To be able to detect naming collision, we need to keep around
the "GUID" using their original name without taking the linkage
into account.
Reviewers: tejohnson
Subscribers: joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D19454
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267304 91177308-0d34-0410-b5e6-96231b3b80d8
Eliminate DITypeIdentifierMap and make DITypeRef a thin wrapper around
DIType*. It is no longer legal to refer to a DICompositeType by its
'identifier:', and DIBuilder no longer retains all types with an
'identifier:' automatically.
Aside from the bitcode upgrade, this is mainly removing logic to resolve
an MDString-based reference to an actualy DIType. The commits leading
up to this have made the implicit type map in DICompileUnit's
'retainedTypes:' field superfluous.
This does not remove DITypeRef, DIScopeRef, DINodeRef, and
DITypeRefArray, or stop using them in DI-related metadata. Although as
of this commit they aren't serving a useful purpose, there are patchces
under review to reuse them for CodeView support.
The tests in LLVM were updated with deref-typerefs.sh, which is attached
to the thread "[RFC] Lazy-loading of debug info metadata":
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098318.html
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267296 91177308-0d34-0410-b5e6-96231b3b80d8
Each reference to an unresolved MDNode is expensive, since the RAUW
support in MDNode uses a separate allocation and side map. Since
a distinct MDNode doesn't require its operands on creation (unlike
uniuqed nodes, there's no need to check for structural equivalence),
use nullptr for any of its unresolved operands. Besides reducing the
burden on MDNode maps, this can avoid allocating temporary MDNodes in
the first place.
We need some way to track operands. Invent DistinctMDOperandPlaceholder
for this purpose, which is a Metadata subclass that holds an ID and
points at its single user. DistinctMDOperandPlaceholder::replaceUseWith
is just like RAUW, but its name highlights that there is only ever
exactly one use.
There is no support for moving (or, obviously, copying) these. Move
support would be possible but expensive; leaving it unimplemented
prevents user error. In the BitcodeReader I originally considered
allocating on a BumpPtrAllocator and keeping a vector of pointers to
them, and then I realized that std::deque implements exactly this.
A couple of obvious follow-ups:
- Change ValueEnumerator to emit distinct nodes first to take more
advantage of this optimization. (How convenient... I think I might
have a couple of patches for this.)
- Change DIBuilder and its consumers (like CGDebugInfo in clang) to
use something like this when constructing debug info in the first
place.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267270 91177308-0d34-0410-b5e6-96231b3b80d8
Consistently use the IsDistinct variable and start relying on it in
GET_OR_DISTINCT. This change has NFC, but prepares for using IsDistinct
to optimize the behaviour of the getMD() and getMDOrNull() helpers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267268 91177308-0d34-0410-b5e6-96231b3b80d8
The only functionality change was removing an error check from the
BitcodeReader (and an assertion from DILocation::getImpl) that is
already caught by Verifier::visitDILocation. The Verifier is a better
place for this anyway, and being inconsistent with other subclasses of
MDNode isn't serving anyone.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267267 91177308-0d34-0410-b5e6-96231b3b80d8
This removes the interfaces added (and not yet complete) to support
lazy reading of summaries. This support is not expected to be needed
since we are moving to a model where the full index is only being
traversed in the thin link step, instead of the back ends.
(The second part of this that I plan to do next is remove the
GlobalValueInfo from the ModuleSummaryIndex - it was mostly needed to
support lazy parsing of summaries. The index can instead reference the
summary structures directly.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267097 91177308-0d34-0410-b5e6-96231b3b80d8
Don't use std::vector<TrackingMDRef>, since (at least in some versions
of libc++) std::vector apparently copies values on grow operations
instead of moving them. Found this when I was temporarily deleting the
copy constructor for TrackingMDRef to investigate a performance
bottleneck.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266909 91177308-0d34-0410-b5e6-96231b3b80d8
Add a new method, DICompositeType::buildODRType, that will create or
mutate the DICompositeType for a given ODR identifier, and use it in
LLParser and BitcodeReader instead of DICompositeType::getODRType.
The logic is as follows:
- If there's no node, create one with the given arguments.
- Else, if the current node is a forward declaration and the new
arguments would create a definition, mutate the node to match the
new arguments.
- Else, return the old node.
This adds a missing feature supported by the current DITypeIdentifierMap
(which I'm slowly making redudant). The only remaining difference is
that the DITypeIdentifierMap has a "the-last-one-wins" rule, whereas
DICompositeType::buildODRType has a "the-first-one-wins" rule.
For now I'm leaving behind DICompositeType::getODRType since it has
obvious, low-level semantics that are convenient for unit testing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266786 91177308-0d34-0410-b5e6-96231b3b80d8
Lift the API for debug info ODR type uniquing up a layer. Instead of
clients managing the map directly on the LLVMContext, add a static
method to DICompositeType called getODRType and handle the map in the
background. Also adds DICompositeType::getODRTypeIfExists, so far just
for convenience in the unit tests.
This simplifies the logic in LLParser and BitcodeReader. Because of
argument spam there are actually a few more lines of code now; I'll see
if I come up with a reasonable way to clean that up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266742 91177308-0d34-0410-b5e6-96231b3b80d8
Tighten up the API for debug info ODR type uniquing in LLVMContext. The
only reason to allow other DIType subclasses is to make the unit tests
prettier :/.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266737 91177308-0d34-0410-b5e6-96231b3b80d8
As per David's review, rename everything in the new API for ODR type
uniquing of debug info.
ensureDITypeMap => enableDebugTypeODRUniquing
destroyDITypeMap => disableDebugTypeODRUniquing
hasDITypeMap => isODRUniquingDebugTypes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266713 91177308-0d34-0410-b5e6-96231b3b80d8
Rather than relying on the structural equivalence of DICompositeType to
merge type definitions, use an explicit map on the LLVMContext that
LLParser and BitcodeReader consult when constructing new nodes.
Each non-forward-declaration DICompositeType with a non-empty
'identifier:' field is stored/loaded from the type map, and the first
definiton will "win".
This map is opt-in: clients that expect ODR types from different modules
to be merged must call LLVMContext::ensureDITypeMap.
- Clients that just happen to load more than one Module in the same
LLVMContext won't magically merge types.
- Clients (like LTO) that want to continue to merge types based on ODR
identifiers should opt-in immediately.
I have updated LTOCodeGenerator.cpp, the two "linking" spots in
gold-plugin.cpp, and llvm-link (unless -disable-debug-info-type-map) to
set this.
With this in place, it will be straightforward to remove the DITypeRef
concept (i.e., referencing types by their 'identifier:' string rather
than pointing at them directly).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266549 91177308-0d34-0410-b5e6-96231b3b80d8
Adrian Prantl
Teresa Johnson
Duncan P. N. Exon Smith
Mehdi Amini