249 Commits

Author SHA1 Message Date
Stephen Tozer
a344c9073c [DebugInfo] Add support for variadic DBG_INSTR_REFs in LiveDebugValues
Following support from the previous patches in this stack being added for
variadic DBG_INSTR_REFs to exist, this patch modifies LiveDebugValues to
handle those instructions. Support already exists for DBG_VALUE_LISTs, which
covers most of the work needed to handle these instructions; this patch only
modifies the transferDebugInstrRef function to correctly track them.

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D133927
2023-01-06 23:01:25 +00:00
Stephen Tozer
c383f4d655 [DebugInfo] Allow non-stack_value variadic expressions and use in DBG_INSTR_REF
Prior to this patch, variadic DIExpressions (i.e. ones that contain
DW_OP_LLVM_arg) could only be created by salvaging debug values to create
stack value expressions, resulting in a DBG_VALUE_LIST being created. As of
the previous patch in this patch stack, DBG_INSTR_REF's syntax has been
changed to match DBG_VALUE_LIST in preparation for supporting variadic
expressions. This patch adds some minor changes needed to allow variadic
expressions that aren't stack values to exist, and allows variadic expressions
that are trivially reduceable to non-variadic expressions to be handled
similarly to non-variadic expressions.

Reviewed by: jmorse

Differential Revision: https://reviews.llvm.org/D133926
2023-01-06 19:31:10 +00:00
serge-sans-paille
38818b60c5
Move from llvm::makeArrayRef to ArrayRef deduction guides - llvm/ part
Use deduction guides instead of helper functions.

The only non-automatic changes have been:

1. ArrayRef(some_uint8_pointer, 0) needs to be changed into ArrayRef(some_uint8_pointer, (size_t)0) to avoid an ambiguous call with ArrayRef((uint8_t*), (uint8_t*))
2. CVSymbol sym(makeArrayRef(symStorage)); needed to be rewritten as CVSymbol sym{ArrayRef(symStorage)}; otherwise the compiler is confused and thinks we have a (bad) function prototype. There was a few similar situation across the codebase.
3. ADL doesn't seem to work the same for deduction-guides and functions, so at some point the llvm namespace must be explicitly stated.
4. The "reference mode" of makeArrayRef(ArrayRef<T> &) that acts as no-op is not supported (a constructor cannot achieve that).

Per reviewers' comment, some useless makeArrayRef have been removed in the process.

This is a follow-up to https://reviews.llvm.org/D140896 that introduced
the deduction guides.

Differential Revision: https://reviews.llvm.org/D140955
2023-01-05 14:11:08 +01:00
Stephen Tozer
6d169089f6 [DebugInfo] Add function to test debug values for equivalence
This patch adds a new function that can be used to check all the
properties, other than the machine values, of a pair of debug values for
equivalence. This is done by folding the "directness" into the
expression, converting the expression to variadic form if it is not
already in that form, and then comparing directly. In a few places which
check whether two debug values are identical to see if their ranges can
be merged, this function will correctly identify cases where two debug
values are expressed differently but have the same meaning, allowing
those ranges to be correctly merged.

Differential Revision: https://reviews.llvm.org/D136173
2022-12-19 17:14:25 +00:00
Felipe de Azevedo Piovezan
57a0990e61 [nfc][DebugInfo] Move subprogram rewriting utility to header
This utility will be useful in subsequent patches, as such we expose it
in the DebugInfoMetadata header.

Depends on D139669

Differential Revision: https://reviews.llvm.org/D139670
2022-12-12 09:24:04 -05:00
Jonas Hahnfeld
c9cb4fc761 [DebugInfo] Store optional DIFile::Source as pointer
getCanonicalMDString() also returns a nullptr for empty strings, which
tripped over the getSource() method. Solve the ambiguity of no source
versus an optional containing a nullptr by simply storing a pointer.

Differential Revision: https://reviews.llvm.org/D138658
2022-12-08 09:58:33 +01:00
Krzysztof Parzyszek
0ca43d4488 DebugInfoMetadata: convert Optional to std::optional 2022-12-04 11:52:02 -06:00
Kazu Hirata
e842c06c2d [IR] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-02 20:05:20 -08:00
OCHyams
a2620e00ff [Assignment Tracking][3/*] Add DIAssignID metadata boilerplate
The Assignment Tracking debug-info feature is outlined in this RFC:

https://discourse.llvm.org/t/
rfc-assignment-tracking-a-better-way-of-specifying-variable-locations-in-ir

Add the DIAssignID metadata attachment boilerplate. Includes a textual-bitcode
roundtrip test and tests that the verifier and parser catch badly formed IR.

This piece of metadata links together stores (used as an attachment) and the
yet-to-be-added llvm.dbg.assign debug intrinsic (used as an operand).

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D132222
2022-11-07 09:05:56 +00:00
OCHyams
fac26edae5 Revert "[Assignment Tracking][3/*] Add DIAssignID metadata boilerplate"
This reverts commit c285df77e9b78f971f9cd9d025248c20b030cc2a.

A sanitizer bot found an issue:
https://lab.llvm.org/buildbot/#/builders/5/builds/28809/steps/13/logs/stdio
2022-11-03 13:46:00 +00:00
OCHyams
e53c4c6d86 [Assignment Tracking][3/*] Add DIAssignID metadata boilerplate
The Assignment Tracking debug-info feature is outlined in this RFC:

https://discourse.llvm.org/t/
rfc-assignment-tracking-a-better-way-of-specifying-variable-locations-in-ir

Add the DIAssignID metadata attachment boilerplate. Includes a textual-bitcode
roundtrip test and tests that the verifier and parser catch badly formed IR.

This piece of metadata links together stores (used as an attachment) and the
yet-to-be-added llvm.dbg.assign debug intrinsic (used as an operand).

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D132222
2022-11-03 11:24:18 +00:00
OCHyams
e1b3d7ab44 Account for memory locations in DIExpression::createFragmentExpression
createFragmentExpression rejects expressions containing certain ops, like
DW_OP_plus, that may cause the expression to compute a value that can't be
split.

Teach createFragmentExpression that the value loaded from an address computed
using those ops is safe to split.

Update a unittest to account for and test this change.

Reviewed By: StephenTozer

Differential Revision: https://reviews.llvm.org/D136243
2022-10-27 08:29:39 +01:00
Juan Manuel MARTINEZ CAAMAÑO
854b1bca60 [DebugInfo] getMergedLocation: Maintain the line number if they match
getMergedLocation returns a 'line 0' DILocaiton if the two locations
being merged don't perfecly match, even if they are in the same line but
a different column.

This commit adds support to keep the line number if it matches (but only
the column differs). The merged column number is the leftmost between the
two.

Reviewed By: dblaikie, orlando

Differential Revision: https://reviews.llvm.org/D135166
2022-10-25 14:10:21 +00:00
OCHyams
50d9bb6b39 [NFC] Add DebugVariable constructor that takes DbgVariableIntrinsic pointer
Note: The constructor definition cannot be inline without some refactoring as
it introduces a circular dependency between the headers
llvm/IR/DebugInfoMetadata.h (this file) and llvm/IR/IntrinsicInst.h (where
DbgVariableIntrinsic is defined).

Reviewed By: jryans

Differential Revision: https://reviews.llvm.org/D133286
2022-10-20 15:28:00 +01:00
Juan Manuel MARTINEZ CAAMAÑO
b1f76e8c57 [NFC] Remove unused set construction from DILocation::getMergedLocation
Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D134357
2022-09-22 07:00:02 +00:00
Joe Loser
5e96cea1db [llvm] Use std::size instead of llvm::array_lengthof
LLVM contains a helpful function for getting the size of a C-style
array: `llvm::array_lengthof`. This is useful prior to C++17, but not as
helpful for C++17 or later: `std::size` already has support for C-style
arrays.

Change call sites to use `std::size` instead.

Differential Revision: https://reviews.llvm.org/D133429
2022-09-08 09:01:53 -06:00
Adrian Prantl
2d48b403f6 Fix UB in DIExpression::appendOffset()
The absolute value of 0x8000000000000000 does not fit into an int64_t
and UBSan tells us that by crashing.

rdar://98799670

Differential Revision: https://reviews.llvm.org/D132194
2022-08-19 09:16:59 -07:00
Kazu Hirata
0916d96d12 Don't use Optional::hasValue (NFC) 2022-06-20 20:17:57 -07:00
Kazu Hirata
129b531c9c [llvm] Use value_or instead of getValueOr (NFC) 2022-06-18 23:07:11 -07:00
Fangrui Song
557efc9a8b [llvm] Remove unneeded cl::ZeroOrMore for cl::opt options. NFC
Some cl::ZeroOrMore were added to avoid the `may only occur zero or one times!`
error. More were added due to cargo cult. Since the error has been removed,
cl::ZeroOrMore is unneeded.

Also remove cl::init(false) while touching the lines.
2022-06-03 21:59:05 -07:00
Wolfgang Pieb
2740c1875d [NFC][Metadata] Refactor allocation, initalization and deletion of MDNodes.
This patch is refactoring the allocation, initialization and deletion
of MDNodes. It is intended as a preparatory patch for the upcoming
addition of dynamic resizability of MDNodes. It is fundamentally NFC,
but removes the necessity for suppressing the memory sanitizer for
MDNode's operator delete.

Reviewers: dexonsmith

Differential Revision: https://reviews.llvm.org/D125489
2022-05-13 16:05:29 -07:00
Chih-Ping Chen
eab6e94f91 [DebugInfo] Add a TargetFuncName field in DISubprogram for
specifying DW_AT_trampoline as a string. Also update the signature
of DIBuilder::createFunction to reflect this addition.

Differential Revision: https://reviews.llvm.org/D123697
2022-04-15 16:38:23 -04:00
Rong Xu
1712254b3f [SampleFDO] Allow multiple of --enable-fs-discrimintor option [NFC]
Allow users to use multiple of --enable-fs-discriminator option.
When this option is specified multiple times, the last instance wins.
2022-03-08 11:31:20 -08:00
serge-sans-paille
ffe8720aa0 Reduce dependencies on llvm/BinaryFormat/Dwarf.h
This header is very large (3M Lines once expended) and was included in location
where dwarf-specific information were not needed.

More specifically, this commit suppresses the dependencies on
llvm/BinaryFormat/Dwarf.h in two headers: llvm/IR/IRBuilder.h and
llvm/IR/DebugInfoMetadata.h. As these headers (esp. the former) are widely used,
this has a decent impact on number of preprocessed lines generated during
compilation of LLVM, as showcased below.

This is achieved by moving some definitions back to the .cpp file, no
performance impact implied[0].

As a consequence of that patch, downstream user may need to manually some extra
files:

llvm/IR/IRBuilder.h no longer includes llvm/BinaryFormat/Dwarf.h
llvm/IR/DebugInfoMetadata.h no longer includes llvm/BinaryFormat/Dwarf.h

In some situations, codes maybe relying on the fact that
llvm/BinaryFormat/Dwarf.h was including llvm/ADT/Triple.h, this hidden
dependency now needs to be explicit.

$ clang++ -E  -Iinclude -I../llvm/include ../llvm/lib/Transforms/Scalar/*.cpp -std=c++14 -fno-rtti -fno-exceptions | wc -l
after:   10978519
before:  11245451

Related Discourse thread: https://llvm.discourse.group/t/include-what-you-use-include-cleanup
[0] https://llvm-compile-time-tracker.com/compare.php?from=fa7145dfbf94cb93b1c3e610582c495cb806569b&to=995d3e326ee1d9489145e20762c65465a9caeab4&stat=instructions

Differential Revision: https://reviews.llvm.org/D118781
2022-02-04 11:44:03 +01:00
serge-sans-paille
e188aae406 Cleanup header dependencies in LLVMCore
Based on the output of include-what-you-use.

This is a big chunk of changes. It is very likely to break downstream code
unless they took a lot of care in avoiding hidden ehader dependencies, something
the LLVM codebase doesn't do that well :-/

I've tried to summarize the biggest change below:

- llvm/include/llvm-c/Core.h: no longer includes llvm-c/ErrorHandling.h
- llvm/IR/DIBuilder.h no longer includes llvm/IR/DebugInfo.h
- llvm/IR/IRBuilder.h no longer includes llvm/IR/IntrinsicInst.h
- llvm/IR/LLVMRemarkStreamer.h no longer includes llvm/Support/ToolOutputFile.h
- llvm/IR/LegacyPassManager.h no longer include llvm/Pass.h
- llvm/IR/Type.h no longer includes llvm/ADT/SmallPtrSet.h
- llvm/IR/PassManager.h no longer includes llvm/Pass.h nor llvm/Support/Debug.h

And the usual count of preprocessed lines:
$ clang++ -E  -Iinclude -I../llvm/include ../llvm/lib/IR/*.cpp -std=c++14 -fno-rtti -fno-exceptions | wc -l
before: 6400831
after:  6189948

200k lines less to process is no that bad ;-)

Discourse thread on the topic: https://llvm.discourse.group/t/include-what-you-use-include-cleanup

Differential Revision: https://reviews.llvm.org/D118652
2022-02-02 06:54:20 +01:00
Chih-Ping Chen
28bfa57a73 [DebugInfo] Add stringLocationExp field to DIStringType
DIStringType is used to encode the debug info of a character object
in Fortran. A Fortran deferred-length character object is typically
implemented as a pair of the following two pieces of info: An address
of the raw storage of the characters, and the length of the object.
The stringLocationExp field contains the DIExpression to get to the
raw storage.

This patch also enables the emission of DW_AT_data_location attribute
in a DW_TAG_string_type debug info entry based on stringLocationExp
in DIStringType.

A test is also added to ensure that the bitcode reader is backward
compatible with the old DIStringType format.

Differential Revision: https://reviews.llvm.org/D117586
2022-01-26 11:56:57 -05:00
Benjamin Kramer
f15014ff54 Revert "Rename llvm::array_lengthof into llvm::size to match std::size from C++17"
This reverts commit ef8206320769ad31422a803a0d6de6077fd231d2.

- It conflicts with the existing llvm::size in STLExtras, which will now
  never be called.
- Calling it without llvm:: breaks C++17 compat
2022-01-26 16:55:53 +01:00
serge-sans-paille
ef82063207 Rename llvm::array_lengthof into llvm::size to match std::size from C++17
As a conquence move llvm::array_lengthof from STLExtras.h to
STLForwardCompat.h (which is included by STLExtras.h so no build
breakage expected).
2022-01-26 16:17:45 +01:00
Luís Ferreira
665b4138d9 [DebugInfo] run clang-format on some unformatted files
This trivial patch runs clang-format on some unformatted files before
doing logic changes and prevent hard to review diffs.

Differential Revision: https://reviews.llvm.org/D113572
2021-11-11 18:59:41 -08:00
Arthur Eubanks
05963a3d66 Revert "[DebugInfo] Enforce implicit constraints on distinct MDNodes"
This reverts commit ee7652569854af567ba83e5255d70e80cc8619a1.

Causes crashes, see comments in D104827.
2021-11-09 14:27:55 -08:00
Scott Linder
ee76525698 [DebugInfo] Enforce implicit constraints on distinct MDNodes
Add UNIQUED and DISTINCT properties in Metadata.def and use them to
implement restrictions on the `distinct` property of MDNodes:

* DIExpression can currently be parsed from IR or read from bitcode
  as `distinct`, but this property is silently dropped when printing
  to IR. This causes accepted IR to fail to round-trip. As DIExpression
  appears inline at each use in the canonical form of IR, it cannot
  actually be `distinct` anyway, as there is no syntax to describe it.
* Similarly, DIArgList is conceptually always uniqued. It is currently
  restricted to only appearing in contexts where there is no syntax for
  `distinct`, but for consistency it is treated equivalently to
  DIExpression in this patch.
* DICompileUnit is already restricted to always being `distinct`, but
  along with adding general support for the inverse restriction I went
  ahead and described this in Metadata.def and updated the parser to be
  general. Future nodes which have this restriction can share this
  support.

The new UNIQUED property applies to DIExpression and DIArgList, and
forbids them to be `distinct`. It also implies they are canonically
printed inline at each use, rather than via MDNode ID.

The new DISTINCT property applies to DICompileUnit, and requires it to
be `distinct`.

A potential alternative change is to forbid the non-inline syntax for
DIExpression entirely, as is done with DIArgList implicitly by requiring
it appear in the context of a function. For example, we would forbid:

    !named = !{!0}
    !0 = !DIExpression()

Instead we would only accept the equivalent inlined version:

    !named = !{!DIExpression()}

This essentially removes the ability to create a `distinct` DIExpression
by construction, as there is no syntax for `distinct` inline. If this
patch is accepted as-is, the result would be that the non-canonical
version is accepted, but the following would be an error and produce a diagnostic:

    !named = !{!0}
    ; error: 'distinct' not allowed for !DIExpression()
    !0 = distinct !DIExpression()

Also update some documentation to consistently use the inline syntax for
DIExpression, and to describe the restrictions on `distinct` for nodes
where applicable.

Reviewed By: StephenTozer, t-tye

Differential Revision: https://reviews.llvm.org/D104827
2021-11-09 18:19:11 +00:00
Yuanfang Chen
7c3fa52785 [DebugInfo] Skip ODRUniquing for mismatched tags
Otherwise, ODRUniquing would map some member method/variable MDNodes
to have enum type DIScope, resulting in invalid debug info and bad
DWARF.

- Add a Verifier check that when a 'scope:' operand is an ODR type that is not an enum.
- Makes ODRUniquing apply to only ODR types with the same tag so that the debuginfo/DWARF is well-formed.

Reviewed By: probinson, aprantl

Differential Revision: https://reviews.llvm.org/D111770
2021-10-26 15:28:25 -07:00
Alok Kumar Sharma
a5b72abc9e [DebugInfo] Enhance DIImportedEntity to accept children entities
New field `elements` is added to '!DIImportedEntity', representing
list of aliased entities.
This is needed to dump optimized debugging information where all names
in a module are imported, but a few names are imported with overriding
aliases.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D109343
2021-09-16 10:41:55 +05:30
Teresa Johnson
badcd58589 [DIArgList] Re-unique after changing operands to fix non-determinism
We have a large compile showing occasional non-deterministic behavior
that is due to DIArgList not being properly uniqued in some cases. I
tracked this down to handleChangedOperands, for which there is a custom
implementation for DIArgList, that does not take care of re-uniquing
after updating the DIArgList Args, unlike the default version of
handleChangedOperands for MDNode.

Since the Args in the DIArgList form the key for the store, this seems
to be occasionally breaking the lookup in that DenseSet. Specifically,
when invoking DIArgList::get() from replaceVariableLocationOp, very
occasionally it returns a new DIArgList object, when one already exists
having the same exact Args pointers. This in turn causes a subsequent
call to Instruction::isIdenticalToWhenDefined on those two otherwise
identical DIArgList objects during a later pass to return false, leading
to different IR in those rare cases.

I modified DIArgList::handleChangedOperands to perform similar
re-uniquing as the MDNode version used by other metadata node types.
This also necessitated a change to the context destructor, since in some
cases we end up with DIArgList as distinct nodes: DIArgList is the only
metadata node type to have a custom dropAllReferences, so we need to
invoke that version on DIArgList in the DistinctMDNodes store to clean
it up properly.

Differential Revision: https://reviews.llvm.org/D108968
2021-09-01 07:04:02 -07:00
Yonghong Song
1bebc31c61 [DebugInfo] generate btf_tag annotations for func parameters
Generate btf_tag annotations for function parameters.
A field "annotations" is introduced to DILocalVariable, and
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates how
annotations are encoded in IR:
    distinct !DILocalVariable(name: "info",, arg: 1, ..., annotations: !10)
    !10 = !{!11, !12}
    !11 = !{!"btf_tag", !"a"}
    !12 = !{!"btf_tag", !"b"}

Differential Revision: https://reviews.llvm.org/D106620
2021-08-26 14:18:30 -07:00
Yonghong Song
30c288489a [DebugInfo] generate btf_tag annotations for DIGlobalVariable
Generate btf_tag annotations for DIGlobalVariable.
A field "annotations" is introduced to DIGlobalVariable, and
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates how
annotations are encoded in IR:
    distinct !DIGlobalVariable(..., annotations: !10)
    !10 = !{!11, !12}
    !11 = !{!"btf_tag", !"a"}
    !12 = !{!"btf_tag", !"b"}

Differential Revision: https://reviews.llvm.org/D106619
2021-08-26 10:03:44 -07:00
Yonghong Song
d383df32c0 [DebugInfo] generate btf_tag annotations for DISubprogram types
Generate btf_tag annotations for DISubprogram types.
A field "annotations" is introduced to DISubprogram, and
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates how
annotations are encoded in IR:
    distinct !DISubprogram(..., annotations: !10)
    !10 = !{!11, !12}
    !11 = !{!"btf_tag", !"a"}
    !12 = !{!"btf_tag", !"b"}

Differential Revision: https://reviews.llvm.org/D106618
2021-08-26 08:24:19 -07:00
Yonghong Song
430e223881 [DebugInfo] generate btf_tag annotations for DIDerived types
Generate btf_tag annotations for DIDrived types. More specifically,
clang frontend generates the btf_tag annotations for record
fields. The annotations are represented as an DINodeArray
in DebugInfo. The following example illustrate how
annotations are encoded in IR:
      distinct !DIDerivedType(tag: DW_TAG_member, ..., annotations: !10)
      !10 = !{!11, !12}
      !11 = !{!"btf_tag", !"a"}
      !12 = !{!"btf_tag", !"b"}

Differential Revision: https://reviews.llvm.org/D106616
2021-08-20 12:06:37 -07:00
Yonghong Song
0b32dca12e Reland [DebugInfo] generate btf_tag annotations for DIComposite types
Clang patch D106614 added attribute btf_tag support. This patch
generates btf_tag annotations for DIComposite types.
A field "annotations" is introduced to DIComposite, and the
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates
how annotations are encoded in IR:
  distinct !DICompositeType(..., annotations: !10)
  !10 = !{!11, !12}
  !11 = !{!"btf_tag", !"a"}
  !12 = !{!"btf_tag", !"b"}
Each btf_tag annotation is represented as a 2D array of
meta strings. Each record may have more than one
btf_tag annotations, as in the above example.

Reland with additional fixes for llvm/unittests/IR/DebugTypeODRUniquingTest.cpp.

Differential Revision: https://reviews.llvm.org/D106615
2021-08-19 17:33:50 -07:00
Yonghong Song
c1169b8bd3 Revert "[DebugInfo] generate btf_tag annotations for DIComposite types"
This reverts commit 2fded193e7a8fb5bd8fb339f00fd9de686390530.

Builtbot reports some test failures. Revert now so I can take time
to fix the issues.
2021-08-19 15:54:38 -07:00
Yonghong Song
2fded193e7 [DebugInfo] generate btf_tag annotations for DIComposite types
Clang patch D106614 added attribute btf_tag support. This patch
generates btf_tag annotations for DIComposite types.
A field "annotations" is introduced to DIComposite, and the
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates
how annotations are encoded in IR:
  distinct !DICompositeType(..., annotations: !10)
  !10 = !{!11, !12}
  !11 = !{!"btf_tag", !"a"}
  !12 = !{!"btf_tag", !"b"}
Each btf_tag annotation is represented as a 2D array of
meta strings. Each record may have more than one
btf_tag annotations, as in the above example.

Differential Revision: https://reviews.llvm.org/D106615
2021-08-19 15:37:44 -07:00
Paul Robinson
75aa3d520d Add a DIExpression const-folder to prevent silly expressions.
It's entirely possible (because it actually happened) for a bool
variable to end up with a 256-bit DW_AT_const_value.  This came about
when a local bool variable was initialized from a bitfield in a
32-byte struct of bitfields, and after inlining and constant
propagation, the variable did have a constant value. The sequence of
optimizations had it carrying "i256" values around, but once the
constant made it into the llvm.dbg.value, no further IR changes could
affect it.

Technically the llvm.dbg.value did have a DIExpression to reduce it
back down to 8 bits, but the compiler is in no way ready to emit an
oversized constant *and* a DWARF expression to manipulate it.
Depending on the circumstances, we had either just the very fat bool
value, or an expression with no starting value.

The sequence of optimizations that led to this state did seem pretty
reasonable, so the solution I came up with was to invent a DWARF
constant expression folder.  Currently it only does convert ops, but
there's no reason it couldn't do other ops if that became useful.

This broke three tests that depended on having convert ops survive
into the DWARF, so I added an operator that would abort the folder to
each of those tests.

Differential Revision: https://reviews.llvm.org/D106915
2021-08-05 06:14:40 -07:00
Jonas Devlieghere
52b5491a21 Revert "[DebugInfo] Enforce implicit constraints on distinct MDNodes"
This reverts commit 8cd35ad854ab4458fd509447359066ea3578b494.

It breaks `TestMembersAndLocalsWithSameName.py` on GreenDragon and
Mikael Holmén points out in D104827 that bitcode files created with the
patch cannot be parsed with binaries built before it.
2021-07-02 15:57:07 -07:00
Scott Linder
8cd35ad854 [DebugInfo] Enforce implicit constraints on distinct MDNodes
Add UNIQUED and DISTINCT properties in Metadata.def and use them to
implement restrictions on the `distinct` property of MDNodes:

* DIExpression can currently be parsed from IR or read from bitcode
  as `distinct`, but this property is silently dropped when printing
  to IR. This causes accepted IR to fail to round-trip. As DIExpression
  appears inline at each use in the canonical form of IR, it cannot
  actually be `distinct` anyway, as there is no syntax to describe it.
* Similarly, DIArgList is conceptually always uniqued. It is currently
  restricted to only appearing in contexts where there is no syntax for
  `distinct`, but for consistency it is treated equivalently to
  DIExpression in this patch.
* DICompileUnit is already restricted to always being `distinct`, but
  along with adding general support for the inverse restriction I went
  ahead and described this in Metadata.def and updated the parser to be
  general. Future nodes which have this restriction can share this
  support.

The new UNIQUED property applies to DIExpression and DIArgList, and
forbids them to be `distinct`. It also implies they are canonically
printed inline at each use, rather than via MDNode ID.

The new DISTINCT property applies to DICompileUnit, and requires it to
be `distinct`.

A potential alternative change is to forbid the non-inline syntax for
DIExpression entirely, as is done with DIArgList implicitly by requiring
it appear in the context of a function. For example, we would forbid:

    !named = !{!0}
    !0 = !DIExpression()

Instead we would only accept the equivalent inlined version:

    !named = !{!DIExpression()}

This essentially removes the ability to create a `distinct` DIExpression
by construction, as there is no syntax for `distinct` inline. If this
patch is accepted as-is, the result would be that the non-canonical
version is accepted, but the following would be an error and produce a diagnostic:

    !named = !{!0}
    ; error: 'distinct' not allowed for !DIExpression()
    !0 = distinct !DIExpression()

Also update some documentation to consistently use the inline syntax for
DIExpression, and to describe the restrictions on `distinct` for nodes
where applicable.

Reviewed By: StephenTozer, t-tye

Differential Revision: https://reviews.llvm.org/D104827
2021-06-28 21:20:04 +00:00
Stephen Tozer
c72705678c Partial Reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands"
This is a partial reapply of the original commit and the followup commit
that were previously reverted; this reapply also includes a small fix
for a potential source of non-determinism, but also has a small change
to turn off variadic debug value salvaging, to ensure that any future
revert/reapply steps to disable and renable this feature do not risk
causing conflicts.

Differential Revision: https://reviews.llvm.org/D91722

This reverts commit 386b66b2fc297cda121a3cc8a36887a6ecbcfc68.
2021-06-24 09:46:38 +01:00
Hans Wennborg
386b66b2fc Revert "3rd Reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands""
> This reapplies c0f3dfb9, which was reverted following the discovery of
> crashes on linux kernel and chromium builds - these issues have since
> been fixed, allowing this patch to re-land.

This reverts commit 36ec97f76ac0d8be76fb16ac521f55126766267d.

The change caused non-determinism in the compiler, see comments on the code
review at https://reviews.llvm.org/D91722.

Reverting to unbreak people's builds until that can be addressed.

This also reverts the follow-up "[DebugInfo] Limit the number of values
that may be referenced by a dbg.value" in
a0bd6105d80698c53ceaa64bbe6e3b7e7bbf99ee.
2021-06-08 14:54:08 +02:00
Stephen Tozer
36ec97f76a 3rd Reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands"
This reapplies c0f3dfb9, which was reverted following the discovery of
crashes on linux kernel and chromium builds - these issues have since
been fixed, allowing this patch to re-land.

This reverts commit 4397b7095d640f9b9426c4d0135e999c5a1de1c5.
2021-05-21 11:06:20 +01:00
Rong Xu
886629a8c9 [SampleFDO] New hierarchical discriminator for Flow Sensitive SampleFDO
This patch implements first part of Flow Sensitive SampleFDO (FSAFDO).
It has the following changes:
(1) disable current discriminator encoding scheme,
(2) new hierarchical discriminator for FSAFDO.

For this patch, option "-enable-fs-discriminator=true" turns on the new
functionality. Option "-enable-fs-discriminator=false" (the default)
keeps the current SampleFDO behavior. When the fs-discriminator is
enabled, we insert a flag variable, namely, llvm_fs_discriminator, to
the object. This symbol will checked by create_llvm_prof tool, and used
to generate a profile with FS-AFDO discriminators enabled. If this
happens, for an extbinary format profile, create_llvm_prof tool
will add a flag to profile summary section.

Differential Revision: https://reviews.llvm.org/D102246
2021-05-18 16:23:43 -07:00
Nathan Chancellor
4397b7095d
Revert "Re-reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands""
This reverts commit 791930d74087b8ae8901172861a0fd21a211e436, as per
https://llvm.org/docs/DeveloperPolicy.html#patch-reversion-policy.

I observed breakage with the Linux kernel, as reported at
https://reviews.llvm.org/D91722#2724321

Fixes exist at
https://reviews.llvm.org/D101523
https://reviews.llvm.org/D101540

but they have not landed so to unbreak the tree for the weekend, revert
this commit.

Commit b11e4c990771 ("Revert "[DebugInfo] Drop DBG_VALUE_LISTs with an
excessive number of debug operands"") only reverted one follow-up fix,
not the original patch that broke the kernel.

e
2021-04-30 20:23:21 -07:00
Stephen Tozer
791930d740 Re-reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands"
Previous build failures were caused by an error in bitcode reading and
writing for DIArgList metadata, which has been fixed in e5d844b587.
There were also some unnecessary asserts that were being triggered on
certain builds, which have been removed.

This reverts commit dad5caa59e6b2bde8d6cf5b64a972c393c526c82.
2021-04-23 10:54:01 +01:00