This simplifies an upcoming patch to support the RemoveDIs project (tracking
variable locations without using intrinsics).
Next in this series is #73500.
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
With intrinsics representing debug-info, we just clone all the
intrinsics when inlining a function and don't think about it any
further. With non-instruction debug-info however we need to be a bit
more careful and manually move the debug-info from one place to another.
For the most part, this means keeping a "cursor" during block cloning of
where we last copied debug-info from, and performing debug-info copying
whenever we successfully clone another instruction.
There are several utilities in LLVM for doing this, all of which now
need to manually call cloneDebugInfo. The testing story for this is not
well covered as we could rely on normal instruction-cloning mechanisms
to do all the hard stuff. Thus, I've added a few tests to explicitly
test dbg.value behaviours, ahead of them becoming not-instructions.
It seems TypeSize is currently broken in the sense that:
TypeSize::Fixed(4) + TypeSize::Scalable(4) => TypeSize::Fixed(8)
without failing its assert that explicitly tests for this case:
assert(LHS.Scalable == RHS.Scalable && ...);
The reason this fails is that `Scalable` is a static method of class
TypeSize,
and LHS and RHS are both objects of class TypeSize. So this is
evaluating
if the pointer to the function Scalable == the pointer to the function
Scalable,
which is always true because LHS and RHS have the same class.
This patch fixes the issue by renaming `TypeSize::Scalable` ->
`TypeSize::getScalable`, as well as `TypeSize::Fixed` to
`TypeSize::getFixed`,
so that it no longer clashes with the variable in
FixedOrScalableQuantity.
The new methods now also better match the coding standard, which
specifies that:
* Variable names should be nouns (as they represent state)
* Function names should be verb phrases (as they represent actions)
In present-day debug-info, when you delete all instructions, you delete
all their debug-info with it because debug-info is stored in
instructions. With debug-info stored in DPValue objects however,
deleting instructions causes DPValue objects to clump together into a
large blob of debug-info that hangs around in the block, as nothing has
explicitly deleted it.
To restore this behaviour, scatter calls to dropDbgValues around in
places that used to delete chunks of dbg.values, for example during
stripDebugInfo and in the code that deletes everything after an
Unreachable instruction. DCE is another example.
The tests with --try... added to them are new scenarios where we can now
correctly replicate the "normal" debug-info behaviour. Alas, there's no
explicit test for the opt -strip-debug option though (in dbg.value mode
or DPValue mode).
This patch extends findDbgValue and friends to optionally fill out a vector
of DPValue pointers, containing DPValues that refer to the sought Value.
This will allow us to incrementally add instrumentation to other
optimisation passes one-at-a-time, while un-instrumented passes will not
(yet) update DPValues.
Unit tests to check this behaves in the same way as dbg.values.
RunTimeLang is already supported by DICompositeType, and already used by
structs and unions. Add a new parameter in the class and enumeration
create methods, so they can use the RunTimeLang attribute as well.
This was reverted because it broke the OCaml LLVM bindings.
Relanding the original patch but without changing the C-API.
They'll continue to work just fine as they do today. If in the
future there is a need to pass a new tag to the C-API for creating
static members, then we'll make the change to the OCaml bindings
at that time.
Original commit message:
"""
This patch adds the LLVM-side infrastructure to implement DWARFv5 issue
161118.1: "DW_TAG for C++ static data members".
The clang-side of this patch will simply construct the DIDerivedType
with a different DW_TAG.
"""
This reverts commit 9a9933fae23249fbf6cf5b3c090e630f578b7f98.
The OCaml bindings were using `LLVMDIBuilderCreateStaticMemberType`,
causing the API change in `9a9933fae23249fbf6cf5b3c090e630f578b7f98`
to break buildbots that built the bindings. Revert until we figure out
whether to fixup the bindings or just not change the C-API
This patch adds the LLVM-side infrastructure to implement DWARFv5 issue
161118.1: "DW_TAG for C++ static data members".
The clang-side of this patch will simply construct the DIDerivedType
with a different DW_TAG.
This caused asserts:
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp:2331:
virtual void llvm::DwarfDebug::endFunctionImpl(const llvm::MachineFunction *):
Assertion `LScopes.getAbstractScopesList().size() == NumAbstractSubprograms &&
"getOrCreateAbstractScope() inserted an abstract subprogram scope"' failed.
See comment on the code review for reproducer.
> RFC https://discourse.llvm.org/t/rfc-dwarfdebug-fix-and-improve-handling-imported-entities-types-and-static-local-in-subprogram-and-lexical-block-scopes/68544
>
> Similar to imported declarations, the patch tracks function-local types in
> DISubprogram's 'retainedNodes' field. DwarfDebug is adjusted in accordance with
> the aforementioned metadata change and provided a support of function-local
> types scoped within a lexical block.
>
> The patch assumes that DICompileUnit's 'enums field' no longer tracks local
> types and DwarfDebug would assert if any locally-scoped types get placed there.
>
> Reviewed By: jmmartinez
>
> Differential Revision: https://reviews.llvm.org/D144006
This reverts commit f8aab289b5549086062588fba627b0e4d3a5ab15.
This function otherwise crashes. This behavior has been incorrect since
its introduction in 260b581498bed0b847e7e086852e0082d266711d (D46627).
Reviewed By: scott.linder
Differential Revision: https://reviews.llvm.org/D154630
This commit removes constness from DILocation::getMergedLocation and
fixes all its users accordingly.
Having constness on the parameters forced the return type to be const
as well, which does force usage of `const_cast` when the location needs
to be used in metadata nodes.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D149942
Do not convert dbg.declares to dbg.assigns for variables backed by scalable
vector allocas as this isn't yet supported.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D149959
Without this patch, in `getAssignmentInfo` the result of `getTypeSizeInBits` is
cast to `uint64_t`, which a) is an operation that will eventually be
unsupported by the API according to the comments, and b) causes an assertion
failure if the type is a scalable vector. Don't cast the `TypeSize` to
`uint64_t` and check `isScalable` before getting the fixed size.
This can result in incorrect variable locations, see llvm.org/PR62346 (but is
better than crashing).
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D149137
The out-param vector from findDbgValues and findDbgUsers should not include
duplicates, which is possible if the debug intrinsic uses the value multiple
times. This filter is already in place for multiple uses in a `DIArgLists`;
extend it to cover dbg.assigns too because a Value may be used in both the
address and value components.
Additionally, refactor the duplicated functionality between findDbgValues and
FindDbgUsers into a new function findDbgIntrinsics.
Reviewed By: jmorse, StephenTozer
Differential Revision: https://reviews.llvm.org/D148788
`shortenAssignment` inserts dbg.assigns with fragments describing the dead part
of a shortened store after each dbg.assign linked to the store.
Without this patch it doesn't take into account that the dead part of a
shortened store may be outside the bounds of a variable of a linked
dbg.assign. It also doesn't correctly account for a non-zero offset in the
address modifying `DIExpression` of the dbg.assign (which is possible for
fragments now even though whole variables currently cannot have a non-zero
offset in their alloca).
Fix this by moving the dead slice into variable-space and performing an
intersect of that adjusted slice with the existing fragment.
This fixes a verifier error reported when building fuchsia with assignment
tracking enabled:
https://ci.chromium.org/ui/p/fuchsia/builders/ci/
clang_toolchain.ci.core.x64-release/b8784000953022145169/overview
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D148536
Debug intrinsics sometimes end up with empty metadata location operands. The
debug intrinsic interfaces return nullptr when retrieving location operand in
this case.
Skip empty-metadata dbg.declares to avoid dereferencing the nullptr. This
doesn't affect the final debug info in any way.
Reviewed By: jryans
Differential Revision: https://reviews.llvm.org/D148204
VLA backed variables currently trip an assertion in SROA with D146987 (enabling
assignment tracking). Disable assignment tracking for VLA variables until that
can be investigated.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D148140
The assertion exists to ensure all variables passed into `trackAssignments` end
up with dbg.assigns associated with their backing allocas. The assertion
compared the passed-in and tracked variables using `DebugVariable`, which
includes the fragment as part of the variable identity.
It is possible for the backing alloca to be smaller than a variable (see test
case). In this case the input variable `(Var X, no fragment, no InlinedAt)`
isn't equal to the dbg.assign variable `(Var X, some fragment, no
InlinedAt)`. To cover this case the assertion now ignores fragments through the
use of `DebugVariableAggregate`.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D148100
In D147777 emitDbgAssign was fixed to discard assignments which touched any
bits outside the bounds of a variable. This patch changes emitDbgAssign to
discard assignments which touch bits only outside the variable bounds, and
creates a truncated fragment expression for stores partially overlapping the
variable. This is necessary because the alloca is interpreted as a store (of
undef), meaning without this patch emitDbgAssign would discard the inital
dbg.assign for a variable that is smaller than the alloca.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D148018
Prior to this patch the trackAssignments function would attribute all stores to
an alloca to all variables linked to the alloca. This is wrong in the case
where the alloca contains variables which are smaller than the alloca, and
caused erroneous fragment information to be generated.
Now stores outside the variable bounds are discarded, and we check whether a
fragment is needed based on whether the store covers the entire variable as
opposed to whether it covers the entire alloca (except for variables of unknown
size).
Note that trackAssignments doesn't yet understand whole variables sitting at
anything other than offset 0 in an alloca - those variables are still tracked
using dbg.declares.
Fixes https://lab.llvm.org/buildbot/#/builders/70/builds/36007
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D147777
Assignment tracking doesn't add value when optimisations are disabled - don't
apply it to functions marked optnone.
Reviewed By: jryans
Differential Revision: https://reviews.llvm.org/D147129
The module flag "debug-info-assignment-tracking" is set by the
declare-to-assign pass to indicate that assignment tracking is enabled. This
patch changes declare-to-assign to only set the flag if it makes a
modification. This lets the compiler avoid doing extra work for no benefit,
such as is currently the case if assignment tracking is requested for a build
with line tables only (-gmlt) or a build without debug info.
Reviewed By: scott.linder
Differential Revision: https://reviews.llvm.org/D144481
This patch adds several missing NamedMDList modifier functions, like
removeNamedMDNode(), eraseNamedMDNode() and insertNamedMDNode().
There is no longer need to access the list directly so it also makes
getNamedMDList() private.
Differential Revision: https://reviews.llvm.org/D143969
The stripDebugLocFromLoopID() may mistakenly remove useful metadata nodes
when they are operands of a child node, which also has DILocation operands.
It can be reproduced by the output of clang for code similar to the following:
for(int i = 0; i < n; i++)
x[i] = 10;
-strip-debug removes the child node of llvm.loop.vectorize.followup_all,
which contains llvm.loop.isvectorized and llvm.loop.unroll.count.
This patch fixes by checking all children nodes and only remove a metadata
node if all its children are DILocation.
Differential Revision: https://reviews.llvm.org/D141909
Remove LLVM flag -experimental-assignment-tracking. Assignment tracking is
still enabled from Clang with the command line -Xclang
-fexperimental-assignment-tracking which tells Clang to ask LLVM to run the
pass declare-to-assign. That pass converts conventional debug intrinsics to
assignment tracking metadata. With this patch it now also sets a module flag
debug-info-assignment-tracking with the value `i1 true` (using the flag conflict
rule `Max` since enabling assignment tracking on IR that contains only
conventional debug intrinsics should cause no issues).
Update the docs and tests too.
Reviewed By: CarlosAlbertoEnciso
Differential Revision: https://reviews.llvm.org/D142027
value() has undesired exception checking semantics and calls
__throw_bad_optional_access in libc++. Moreover, the API is unavailable without
_LIBCPP_NO_EXCEPTIONS on older Mach-O platforms (see
_LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS).
This commit fixes LLVMAnalysis and its dependencies.
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
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 method:
Instruction::mergeDIAssignID(
ArrayRef<const Instruction* > SourceInstructions)
which merges the DIAssignID metadata attachments on `SourceInstructions` and
`this` and replaces uses of the original IDs with the new shared one.
This is used when stores are merged, for example sinking stores out of a
if-diamond CFG or vectorizing contiguous stores.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D133291
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 trackAssignments which adds assignment tracking metadata to a function for
a specified set of variables. The intended callers are the inliner and the
front end - those calls will be added in separate patches.
I've added a pass called declare-to-assign (AssignmentTrackingPass) that
converts dbg.declare intrinsics to dbg.assigns using trackAssignments so that
the function can be easily tested (see
llvm/test/DebugInfo/Generic/track-assignments.ll). The pass could also be used
by front ends to easily test out enabling assignment tracking.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D132225
