D123493 introduced llvm::Module::Min to encode module flags metadata for AArch64
BTI/PAC-RET. llvm::Module::Min does not take effect when the flag is absent in
one module. This behavior is misleading and does not address backward
compatibility problems (when a bitcode with "branch-target-enforcement"==1 and
another without the flag are merged, the merge result is 1 instead of 0).
To address the problems, require Min flags to be non-negative and treat absence
as having a value of zero. For an old bitcode without
"branch-target-enforcement"/"sign-return-address", its value is as if 0.
Differential Revision: https://reviews.llvm.org/D129911
LTO objects might compiled with different `mbranch-protection` flags which will cause an error in the linker.
Such a setup is allowed in the normal build with this change that is possible.
Reviewed By: pcc
Differential Revision: https://reviews.llvm.org/D123493
There is a case when a function has pseudo probe intrinsics but the module it resides does not have the probe desc. This could happen when the current module is not built with `-fpseudo-probe-for-profiling` while a function in it calls some other function from a probed module. In thinLTO mode, the callee function could be imported and inlined into the current function.
While this is undefined behavior, I'm fixing the asm printer to not ICE and warn user about this.
Reviewed By: wenlei
Differential Revision: https://reviews.llvm.org/D121737
2 of the 3 callsite of IRMover::move() pass empty lambda functions. Just
make this parameter llvm::unique_function.
Came about via discussion in D120781. Probably worth making this change
regardless of the resolution of D120781.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D121630
As discussed in:
* https://reviews.llvm.org/D94166
* https://lists.llvm.org/pipermail/llvm-dev/2020-September/145031.html
The GlobalIndirectSymbol class lost most of its meaning in
https://reviews.llvm.org/D109792, which disambiguated getBaseObject
(now getAliaseeObject) between GlobalIFunc and everything else.
In addition, as long as GlobalIFunc is not a GlobalObject and
getAliaseeObject returns GlobalObjects, a GlobalAlias whose aliasee
is a GlobalIFunc cannot currently be modeled properly. Creating
aliases for GlobalIFuncs does happen in the wild (e.g. glibc). In addition,
calling getAliaseeObject on a GlobalIFunc will currently return nullptr,
which is undesirable because it should return the object itself for
non-aliases.
This patch refactors the GlobalIFunc class to inherit directly from
GlobalObject, and removes GlobalIndirectSymbol (while inlining the
relevant parts into GlobalAlias and GlobalIFunc). This allows for
calling getAliaseeObject() on a GlobalIFunc to return the GlobalIFunc
itself, making getAliaseeObject() more consistent and enabling
alias-to-ifunc to be properly modeled in the IR.
I exercised some judgement in the API clients of GlobalIndirectSymbol:
some were 'monomorphized' for GlobalAlias and GlobalIFunc, and
some remained shared (with the type adapted to become GlobalValue).
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D108872
To better reflect the meaning of the now-disambiguated {GlobalValue,
GlobalAlias}::getBaseObject after breaking off GlobalIFunc::getResolverFunction
(D109792), the function is renamed to getAliaseeObject.
Copying IR during linking causes a type mismatch due to the field being missing in IRMover/Valuemapper. Adds the full range of typed attributes including elementtype attribute in the copy functions.
Patch by Chenyang Liu
Differential Revision: https://reviews.llvm.org/D108796
libdevice bitcode provided by NVIDIA is linked with clang/LLVM-generated IR
which uses nvptx*-nvidia-cuda triple. We need to mark them as compatible.
Differential Revision: https://reviews.llvm.org/D108835
For a variable in a comdat nodeduplicate, its initializer may be significant.
E.g. its content may be implicitly referenced by another comdat member (or
required to parallel to another comdat member by the runtime when explicit
section is used). We can clone it into an unnamed private linkage variable to
preserve its content.
This partially fixes PR51394 (Sony's proprietary linker using LTO): no error
will be reported. This is partial because we do not guarantee the global
variable order if the runtime has parallel section requirement.
---
There is a similar issue for regular LTO, but unrelated to PR51394:
with lib/LTO (using either ld.lld or LLVMgold.so), linking two modules
with a weak function of the same name, can leave one weak profc and two
private profd, due to lib/LTO's current deficiency that it mixes the two
concepts together: comdat selection and symbol resolution. If the issue
is considered important, we should suppress private profd for the weak+
regular LTO case.
Reviewed By: phosek
Differential Revision: https://reviews.llvm.org/D108879
When a nodeduplicate COMDAT group contains a weak symbol, choose
a non-weak symbol (or one of the weak ones) rather than reporting
an error. This should address issue PR51394.
With the current IR representation, a generic comdat nodeduplicate
semantics is not representable for LTO. In the linker, sections and
symbols are separate concepts. A dropped weak symbol does not force the
defining input section to be dropped as well (though it can be collected
by GC). In the IR, when a weak linkage symbol is dropped, its associate
section content is dropped as well.
For InstrProfiling, which is where ran into this issue in PR51394, the
deduplication semantic is a sufficient workaround.
Differential Revision: https://reviews.llvm.org/D108689
This is different from symbol resolution based LinkFromSrc. Rename to be
clearer.
In the future we may support a new enum member 'Both' for nodeduplicate. This is
feasible (by renaming to a private linkage GlobalValue), but we need to be
careful not to break InstrProfiling.cpp's expectation of parallel profd/profc.
The challenge is that current LTO symbol resolution only allows to mark one
profc as prevailing: the other profc in another comdat nodeduplicate may be
discarded while its associated profd isn't.
In the textual format, `noduplicates` means no COMDAT/section group
deduplication is performed. Therefore, if both sets of sections are retained, and
they happen to define strong external symbols with the same names,
there will be a duplicate definition linker error.
In PE/COFF, the selection kind lowers to `IMAGE_COMDAT_SELECT_NODUPLICATES`.
The name describes the corollary instead of the immediate semantics. The name
can cause confusion to other binary formats (ELF, wasm) which have implemented/
want to implement the "no deduplication" selection kind. Rename it to be clearer.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D106319
Previously we reliedy on pseudo probe descriptors to look up precomputed GUID during probe emission for inlined probes. Since we are moving to always using unique linkage names, GUID for functions can be computed in place from dwarf names. This eliminates the need of importing pseudo probe descs in thinlto, since those descs should be emitted by the original modules.
This significantly reduces thinlto memory footprint in some extreme case where the number of imported modules for a single module is massive.
Test Plan:
Reviewed By: wenlei
Differential Revision: https://reviews.llvm.org/D105248
3d4f3a0da9 (https://reviews.llvm.org/D20586) avoided rescheduling
a global value that was materialized first through a regular value, and
then again through an alias. This commit catches the dual, avoiding
rescheduling when the global value is first materialized through an
alias.
Differential Revision: https://reviews.llvm.org/D101419
Radar-Id: rdar://75752728
The order of global variables is generated in the order of recursively materializing variables if the global variable has the attribute of hasLocalLinkage or hasLinkOnceLinkage during the module merging. In practice, it is often the exact reverse of source order. This new order may cause performance regression.
The change is to preserve the original lexical order for global variables.
Reviewed By: jdoerfert, dexonsmith
Differential Revision: https://reviews.llvm.org/D94202
I think byval/sret and the others are close to being able to rip out
the code to support the missing type case. A lot of this code is
shared with inalloca, so catch this up to the others so that can
happen.
This patch adds support for intrinsic overloading on unnamed types.
This fixes PR38117 and PR48340 and will also be needed for the Full Restrict Patches (D68484).
The main problem is that the intrinsic overloading name mangling is using 's_s' for unnamed types.
This can result in identical intrinsic mangled names for different function prototypes.
This patch changes this by adding a '.XXXXX' to the intrinsic mangled name when at least one of the types is based on an unnamed type, ensuring that we get a unique name.
Implementation details:
- The mapping is created on demand and kept in Module.
- It also checks for existing clashes and recycles potentially existing prototypes and declarations.
- Because of extra data in Module, Intrinsic::getName needs an extra Module* argument and, for speed, an optional FunctionType* argument.
- I still kept the original two-argument 'Intrinsic::getName' around which keeps the original behavior (providing the base name).
-- Main reason is that I did not want to change the LLVMIntrinsicGetName version, as I don't know how acceptable such a change is
-- The current situation already has a limitation. So that should not get worse with this patch.
- Intrinsic::getDeclaration and the verifier are now using the new version.
Other notes:
- As far as I see, this should not suffer from stability issues. The count is only added for prototypes depending on at least one anonymous struct
- The initial count starts from 0 for each intrinsic mangled name.
- In case of name clashes, existing prototypes are remembered and reused when that makes sense.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D91250
Modified scalable vector types weren't correctly returned at link-time.
The previous behaviour was a FixedVectorType was constructed
when expecting a ScalableVectorType. This commit has added a regression
test which re-creates the failure as well as a fix.
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D96953
Rename the `RF_MoveDistinctMDs` flag passed into `MapValue` and
`MapMetadata` to `RF_ReuseAndMutateDistinctMDs` in order to more
precisely describe its effect and clarify the header documentation.
Found this while helping to investigate PR48841, which pointed out an
unsound use of the flag in `CloneModule()`. For now I've just added a
FIXME there, but I'm hopeful that the new (more precise) name will
prevent other similar errors.
This patch fixes llvm-link assertion when linking external variable
declaration with a definition with appending linkage.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95126
This also removes the empty extra "module asm" that would be created,
and updates the test to reflect that while making it more explicit.
Broken out from https://reviews.llvm.org/D92335
There's a small number of users of this function, they are all updated.
This updates the C API adding a new method LLVMGetTypeByName2 that takes a context and a name.
Differential Revision: https://reviews.llvm.org/D78793
This wasn't properly remapping the type like with the other
attributes, so this would end up hitting a verifier error after
linking different modules using byref.
No longer rely on an external tool to build the llvm component layout.
Instead, leverage the existing `add_llvm_componentlibrary` cmake function and
introduce `add_llvm_component_group` to accurately describe component behavior.
These function store extra properties in the created targets. These properties
are processed once all components are defined to resolve library dependencies
and produce the header expected by llvm-config.
Differential Revision: https://reviews.llvm.org/D90848
We saw the same assertion failure mentioned here
https://bugs.llvm.org/show_bug.cgi?id=42063 in our internal tests.
The failure happens in the same circumstance as D47898 and D66814 where
uniqueing of DICompositeTypes causes `Mapper::mapValue` to be called on
GlobalValues(`G`) from a not-yet-linked module(`M`). The following type-mapping for
`G` may not complete correctly (fail to unique types etc. depending on the
the complexity of the types) because IRLinker::computeTypeMapping is not done for `M`
in this path.
D47898 and D66814 fixed some type-mapping issue after Mapper::mapValue
is called on `G`. However, it seems it did not handle some complex cases. I
think we should delay linking globals like `G` until its owing module is
linked. In this way, we could save unnecessary type mapping and prune
these corner cases. It is also supposed to reduce the total number of structs
ending up in the combined module.
D47898 is reverted (its test is kept) because it regresses the test case here.
D66814 could also be reverted (the `check-all` looks good). But it looks reasonable
anyway, so I thought I should keep it.
Also tested the patch with clang self-host regularLTO/ThinLTO build, things look
good as well.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D87001
For ThinLTO importing we don't need to import all the fields of the DICompileUnit, such as enums, macros, retained types lists. The importation of those fields were previously disabled by setting their value map entries to nullptr. Unfortunately a metadata node can be shared by multiple metadata operands. Setting the map entry to nullptr might result in not importing other metadata unexpectedly. The issue is fixed by explicitly setting the original DICompileUnit fields (still a copy of the source module metadata) to null.
Reviewed By: wenlei, dblaikie
Differential Revision: https://reviews.llvm.org/D86675
PassManager.h is one of the top headers in the ClangBuildAnalyzer frontend worst offenders list.
This exposes a large number of implicit dependencies on various forward declarations/includes in other headers that need addressing.
Now that we have scalable vectors, there's a distinction that isn't
getting captured in the original SequentialType: some vectors don't have
a known element count, so counting the number of elements doesn't make
sense.
In some cases, there's a better way to express the commonality using
other methods. If we're dealing with GEPs, there's GEP methods; if we're
dealing with a ConstantDataSequential, we can query its element type
directly.
In the relatively few remaining cases, I just decided to write out
the type checks. We're talking about relatively few places, and I think
the abstraction doesn't really carry its weight. (See thread "[RFC]
Refactor class hierarchy of VectorType in the IR" on llvmdev.)
Differential Revision: https://reviews.llvm.org/D75661
Summary:
Debug Info Version was changed to use "Max" instead of "Warning" per the
original design intent - but this maxes old/new IR unlinkable, since
mismatched merge styles are a linking failure.
It seems possible/maybe reasonable to actually support the combination
of these two flags: Warn, but then use the maximum value rather than the
first value/earlier module's value.
Reviewers: tejohnson
Differential Revision: https://reviews.llvm.org/D74257
Fangrui Song