Added support for option "-fdebug-info-for-profiling" in flang.
- When the option `-fdebug-info-for-profiling` option is passed,
compiler sets the `DebugInfoForProfiling` flag and triggers the
`AddDiscriminatorsPass`. This pass inserts additional debug metadata,
specifically discriminator values into the IR to improve the profiling
precision.
- Additionally `-add-debug-info` pass has been updated to emit an extra
field, `debugInfoForProfiling: true` inside the generated DICompileUnit
metadata node.
This PR updates `DIDerivedTypeAttr` to support optional file, line and
scope parameters in the same way as `DICompositeTypeAttr`. These
parameters are already supported in the `llvm::DIDerivedType`
constructor and were hardcoded to nullptr/0, they are now accessible
from MLIR.
The existing `llvmir-debug.mlir` test has been updated to test these
changes.
The name field of DICompositeTypeAttr was already optional, but
DIBasicTypeAttr and DIStringTypeAttr were not handled consistently. Make
the name parameter of both an OptionalParameter to support LLVM debug
info nodes with no name. Update DebugImporter to use getStringAttrOrNull
when translating the name of these types. Add tests for the null-name
cases in the import and export test files.
This commit removes the creation of NameLocs when importing locations
for LLVM IR functions. This made the generated fused location more
complex by adding no valuable additional information to it. Note that
removing it has no effect on the roundtrip from LLVM IR back to LLVM IR.
This patch sets up `DICompileUnit` to support the DWARFv6
`DW_AT_language_name` and `DW_AT_language_version` attributes (which are
set to replace `DW_AT_language`). This patch changes the
`DICompileUnit::SourceLanguage` field type to a `DISourceLanguageName`
that encapsulates the notion of "versioned vs. unversioned name". A
"versioned" name is one that has an associated version stored separately
in `DISourceLanguageName::Version`.
This patch just changes all the clients of the `getSourceLanguage` API
to the expect a `DISourceLanguageName`. Currently they all just `assert`
(via `DISourceLanguageName::getUnversionedName`) that we're dealing with
"unversioned names" (i.e., the pre-DWARFv6 language codes). In follow-up
patches (e.g., draft is at
https://github.com/llvm/llvm-project/pull/162261), when we start
emitting versioned language codes, the `getUnversionedName` calls can
then be adjusted to `getName`.
**Implementation considerations**
* We could have added a new member to `DICompileUnit` alongside the
existing `SourceLanguage` field. I don't think this would have made the
transition any simpler (clients would still need to be aware of
"versioned" vs. "unversioned" language names). I felt that encapsulating
this inside a `DISourceLanguageName` was easier to reason about for
maintainers.
* Currently DISourceLanguageName is a `12` byte structure. We could
probably pack all the info inside a `uint64_t` (16-bits for the name,
32-bits for the version, 1-bit for answering the `hasVersionedName`).
Just to keep the prototype simple I used a `std::optional`. But since
the guts of the structure are hidden, we can always change the layout to
a more compact representation instead.
**How to review**
* The new `DISourceLanguageName` structure is defined in
`DebugInfoMetadata.h`. All the other changes fall out from changing the
`DICompileUnit::SourceLanguage` from `unsigned` to
`DISourceLanguageName`.
This commit moves the "element" param of `DICompositeType` to the end of
the parameter list. This is required as there seems to be a bug in the
attribute parser that breaks a print + parse roundtrip.
Related ticket: https://github.com/llvm/llvm-project/issues/156623
These are identified by misc-include-cleaner. I've filtered out those
that break builds. Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
`DIGenericSubrange` is used when the dimensions of the arrays are
unknown at build time (e.g. assumed-rank arrays in Fortran). It has same
`lowerBound`, `upperBound`, `count` and `stride` fields as in
`DISubrange` and its translation looks quite similar as a result.
---------
Co-authored-by: Tobias Gysi <tobias.gysi@nextsilicon.com>
A COMMON block is a named area of memory that holds a collection of
variables. Fortran subprograms may map the COMMON block memory area to a
list of variables. A common block is represented in LLVM debug by
DICommonBlock.
This PR adds support for this in MLIR. The changes are mostly mechanical
apart from small change to access the DICompileUnit when the scope of
the variable is DICommonBlock.
---------
Co-authored-by: Tobias Gysi <tobias.gysi@nextsilicon.com>
LLVM already supports `DW_TAG_LLVM_annotation` entries for subprograms,
but this hasn't been surfaced to the LLVM dialect.
I'm doing the minimal amount of work to support string-based
annotations, which is useful for attaching metadata to
functions, which is useful for debuggers to offer features beyond basic
DWARF.
As LLVM already supports this, this patch is not controversial.
This reverts commit fa93be4, restoring
commit d884b77, with fixes that ensure the CAPI declarations are
exported properly.
This commit implements LLVM_DIRecursiveTypeAttrInterface for the
DISubprogramAttr to ensure cyclic subprograms can be imported properly.
In the process multiple shortcuts around the recently introduced
DIImportedEntityAttr can be removed.
This commit implements LLVM_DIRecursiveTypeAttrInterface for the
DISubprogramAttr to ensure cyclic subprograms can be imported properly.
In the process multiple shortcuts around the recently introduced
DIImportedEntityAttr can be removed.
The `DIImporedEntity` can be used to represent imported entities like
C++'s namespace with using directive or fortran's moudule with use
statement.
This PR adds `DIImportedEntityAttr` and 2-way translation from
`DIImportedEntity` to `DIImportedEntityAttr` and vice versa.
When an entity is imported in a function, the `retainedNodes` field of
the `DISubprogram` contains all the imported nodes. See the C++ code and
the LLVM IR below.
```
void test() {
using namespace n1;
...
}
!2 = !DINamespace(name: "n1", scope: null)
!16 = distinct !DISubprogram(name: "test", ..., retainedNodes: !19) !19 = !{!20}
!20 = !DIImportedEntity(tag: DW_TAG_imported_module, scope: !16, entity: !2 ...)
```
This PR makes sure that the translation from mlir to `retainedNodes`
field happens correctly both ways.
To side step the cyclic dependency between `DISubprogramAttr` and `DIImportedEntityAttr`,
we have decided to not have `scope` field in the `DIImportedEntityAttr` and it is inferred
from the entity which hold the list of `DIImportedEntityAttr`. A `retainedNodes` field has been
added in the `DISubprogramAttr` which contains the list of `DIImportedEntityAttr` for that
function.
This PR currently does not handle entities imported in a global scope
but that should be easy to handle in a subsequent PR.
Use the new CyclicReplacerCache from
https://github.com/llvm/llvm-project/pull/98202 to support importing of
recursive DITypes in LLVM dialect's DebugImporter. This helps simplify
the implementation, allows for separate testing of the cache infra
itself, and as a result we even got more efficient translations.
This PR handle translation of DIStringType. Mostly mechanical changes to
translate DIStringType to/from DIStringTypeAttr. The 'stringLength'
field is 'DIVariable' in DIStringType. As there was no `DIVariableAttr`
previously, it has been added to ease the translation.
---------
Co-authored-by: Tobias Gysi <tobias.gysi@nextsilicon.com>
The DISubrange can take integer, dwarf expressions or variables. The
current translation only handled integers. This PR adds handling of
dwarf expressions and variables.
The fortran arrays use 'dataLocation', 'rank', 'allocated' and
'associated' fields of the DICompositeType. These were not available in
'DICompositeTypeAttr'. This PR adds the missing fields.
---------
Co-authored-by: Tobias Gysi <tobias.gysi@nextsilicon.com>
This field is present in LLVM, but was missing from the MLIR wrapper
type. This addition allows MLIR languages to add proper DWARF info for
GPU programs.
This commit fixes a bug in the DICompositeType element ignore mode. It
seems that vectors require the presence of elements, as they otherwise
do not pass the verifier.
This commit introduces a flag to allow skipping the potentially
recursive import of DICompositeType elements. This patch is essentially a
bandaid for the still broken recursive debug type import.
Some of our downstream inputs are produced by excessive usage of
template meta programming, and thus contain tens of thousands of types
that all participate in such recursions. Unfortunately, the series of
patches that introduces type support is not easily revertible due to
being around for a while now and Modular depending on it.
We can consider to revert this change once the type importer has show to
be very performant, but for now we are talking second vs hours to import
specific files.
Followup to this discussion:
https://github.com/llvm/llvm-project/pull/80251#discussion_r1535599920.
The previous debug importer was correct but inefficient. For cases with
mutual recursion that contain more than one back-edge, each back-edge
would result in a new translated instance. This is because the previous
implementation never caches any translated result with unbounded
self-references. This means all translation inside a recursive context
is performed from scratch, which will incur repeated run-time cost as
well as repeated attribute sub-trees in the translated IR (differing
only in their `recId`s).
This PR refactors the importer to handle caching inside a recursive
context.
- In the presence of unbound self-refs, the translation result is cached
in a separate cache that keeps track of the set of dependent unbound
self-refs.
- A dependent cache entry is valid only when all the unbound self-refs
are in scope. Whenever a cached entry goes out of scope, it will be
removed the next time it is looked up.
This revision makes the subprogramFlags field in the DISubprogrammAttr
optional. This is necessary since the DISubprogram attached to a
declaration may have none of the subprogram flags set.
This commit extends the DIDerivedTypeAttr with the `extraData` field.
For now, the type of it is limited to be a `DINodeAttr`, as extending
the debug metadata handling to support arbitrary metadata nodes does not
seem to be necessary so far.
Following the discussion from [this
thread](https://discourse.llvm.org/t/handling-cyclic-dependencies-in-debug-info/67526/11),
this PR adds support for recursive DITypes.
This PR adds:
1. DIRecursiveTypeAttrInterface: An interface that DITypeAttrs can
implement to indicate that it supports recursion. See full description
in code.
2. Importer & exporter support (The only DITypeAttr that implements the
interface is DICompositeTypeAttr, so the exporter is only implemented
for composites too. There will be two methods that each llvm DI type
that supports mutation needs to implement since there's nothing
general).
---------
Co-authored-by: Tobias Gysi <tobias.gysi@nextsilicon.com>
This revision handles the case that the translation of a scope fails due
to cyclic metadata. This mainly affects the import of debug intrinsics
that indirectly take such a scope as metadata argument (e.g. via local
variable or label metadata). This commit ensures we drop intrinsics with
such a dependency on cyclic metadata.
This commit adds an optional distinct attribute parameter to the
DISubprogramAttr. This enables modeling of distinct subprograms, as
required for LLVM IR. This change is required to avoid accidential
uniquing of subprograms on functions that would lead to invalid LLVM IR
post export.
This commit adds a distinct attribute parameter to the DICompileUnit to
enable the modeling of distinctness. LLVM requires DICompileUnits to be
distinct and there are cases where one gets two equivalent compilation
units but LLVM still requires differentiates them. We observed such
cases for combinations of LTO and inline functions.
This patch also changes the DIScopeForLLVMFuncOp pass to a module pass,
to ensure that only one distinct DICompileUnit is created, instead of
one for each function.
This commit ensures that we model DI information for global constants
correctly. These constructs can lack scopes, names, and linkage names,
so these parameters were made optional for the DIGlobalVariable
attribute.
There's an issue in the translator today where, for a CallsiteLoc, if
the callee does not have a DI scope (perhaps due to compile options or
optimizations), it may get propagated the DI scope of its callsite's
parent function, which will create a non-existent DILocation combining
line & col number from one file, and the filename from another.
The root problem is we cannot propagate the parent scope when
translating the callee location, as it no longer applies to inlined
locations (see code diff and hopefully this will make sense).
To facilitate this, the importer is also changed so that callee scopes
are fused with the callee FileLineCol loc, instead of on the Callsite
loc itself. This comes with the benefit that we now have a symmetric
Callsite loc representation. If we required the callee scope be always
annotated on the Callsite loc, it would be hard for generic inlining
passes to maintain that, since it would have to somehow understand the
semantics of the fused metadata and pull it out while inlining.
This PR introduces DIGlobalVariableAttr and
DIGlobalVariableExpressionAttr so that ModuleTranslation can emit the
required metadata needed for debug information about global variable.
The translator implementation for debug metadata needed to be refactored
in order to allow translation of nodes based on MDNode
(DIGlobalVariableExpressionAttr and DIExpression) in addition to
DINode-based nodes.
A DIGlobalVariableExpressionAttr can now be passed to the GlobalOp
operation directly and ModuleTranslation will create the respective
DIGlobalVariable and DIGlobalVariableExpression nodes. The compile unit
that DIGlobalVariable is expected to be configured with will be updated
with the created DIGlobalVariableExpression.
This commit ensures that the debug info import skips `DICompositeTypes`
that have an array type tag and failed to translate the base type. This
is necessary because array `DICompositeTypes` require a base type to be
valid.
Note that this is currently not verified in LLVM, instead it leads to an
explosion of the `ASMPrinter`.
This commit adds a DIModuleAttr to the set of debug info attributes and
extends the LLVM IR import and export to support it.
DIModule metadata is missing in the LLVM LangRef and cannot be produced
from C or C++ input. So far, we only observed classic flang producing
such DI metadata.
Reviewed By: zero9178
Differential Revision: https://reviews.llvm.org/D156969
This commit changes the LLVM IR import to use UnkownLoc for missing
debug locations. This change ensures that we do not accidentially
introduce faulty locations that can influence debugging post export.
This behavior change is not applied to locations of global metadata
operations, as their location will not be exported.
Reviewed By: gysit
Differential Revision: https://reviews.llvm.org/D154416
This revision adds support for the llvm.dbg.label.intrinsic
and the corresponding DILabel metadata.
Reviewed By: Dinistro
Differential Revision: https://reviews.llvm.org/D153975
This commit ensures that no empty debug metadata strings are exported as
these are not legal names. Additionally, this commit ensures that
non-existing strings are not accidentially imported as empty strings.
Reviewed By: gysit
Differential Revision: https://reviews.llvm.org/D144263
This commit introduces the DINamespaceAttr to model LLVM's DINamespace metadata.
Reviewed By: gysit
Differential Revision: https://reviews.llvm.org/D144243
This commit renames the "di_void_result_type" to "di_null_type" as LLVM
does use null not exclusively for void types. An added test demonstrates
this for variadic function declarations, whose DISubroutine indicates the
start of variadic types with `null`.
Reviewed By: gysit
Differential Revision: https://reviews.llvm.org/D144109
This revision fixes the import of LLVM IR to handle debug metadata with
cyclic dependencies. It deletes the elements list of the composite type
if a cyclic dependency is detected. The revision is meant as a band aid
to avoid infinite recursion during the import of cyclic debug metadata.
Long term solutions are currently discussed here:
https://discourse.llvm.org/t/handling-cyclic-dependencies-in-debug-info/67526/4
Reviewed By: Dinistro
Differential Revision: https://reviews.llvm.org/D142086
Previously, the DISubroutineType attribute used an optional result
parameter and an optional argument types array to model the subroutine
signature. LLVM IR debug metadata, on the other hand, has one types
list whose first entry maps to the result type. That entry may be
null to model a void result type. The type list may also be entirely
empty not specifying any type information. The latter is problematic
since the current DISubroutineType attribute cannot express it.
The revision changes DISubroutineTypeAttr to closely follow the
LLVM metadata design. In particular, it uses a single types parameter
array to model the subroutine signature and introduces an explicit
DIVoidResultTypeAttr to model the null entries.
Reviewed By: Dinistro
Differential Revision: https://reviews.llvm.org/D141261
This reverts commit 81f57b6
and relands commit a960547
Fixes flang build and drop_begin on an empty array ref.
Previously, the DISubroutineType attribute used an optional result
parameter and an optional argument types array to model the subroutine
signature. LLVM IR debug metadata, on the other hand, has one types
list whose first entry maps to the result type. That entry may be
null to model a void result type. The type list may also be entirely
empty not specifying any type information. The latter is problematic
since the current DISubroutineType attribute cannot express it.
The revision changes DISubroutineTypeAttr to closely follow the
LLVM metadata design. In particular, it uses a single types parameter
array to model the subroutine signature and introduces an explicit
DIVoidResultTypeAttr to model the null entries.
Reviewed By: Dinistro
Differential Revision: https://reviews.llvm.org/D141261
