By chance, two things have prevented the autoupgrade path being exercised much so far: * LLParser setting the debug-info mode to "old" on seeing intrinsics, * The test in AutoUpgrade.cpp wanting to upgrade into a "new" debug-info block. In practice, this appears to mean this code path hasn't seen the various invalid inputs that can come its way. This commit does a number of things: * Tolerates the various illegal inputs that can be written with debug-intrinsics, and that must be tolerated until the Verifier runs, * Printing illegal/null DbgRecord fields must succeed, * Verifier errors need to localise the function/block where the error is, * Tests that now see debug records will print debug-record errors, Plus a few new tests for other intrinsic-to-debug-record failures modes I found. There are also two edge cases: * Some of the unit tests switch back and forth between intrinsic and record modes at will; I've deleted coverage and some assertions to tolerate this as intrinsic support is now Gone (TM), * In sroa-extract-bits.ll, the order of debug records flips. This is because the autoupgrader upgrades in the opposite order to the basic block conversion routines... which doesn't change the record order, but _does_ change the use list order in Metadata! This should (TM) have no consequence to the correctness of LLVM, but will change the order of various records and the order of DWARF record output too. I tried to reduce this patch to a smaller collection of changes, but they're all intertwined, sorry.
These date back to when the non-intrinsic format of variable locations was still being tested and was behind a compile-time flag, so not all builds / bots would correctly run them. The solution at the time, to get at least some test coverage, was to have tests opt-in to non-intrinsic debug-info if it was built into LLVM. Nowadays, non-intrinsic format is the default and has been on for more than a year, there's no need for this flag to exist. (I've downgraded the flag from "try" to explicitly requesting non-intrinsic format in some places, so that we can deal with tests that are explicitly about non-intrinsic format in their own commit).
`undef` debug info can be replaced with `poison` debug info.
Represent extant metadata uses of a deleted instruction with `poison` instead of `undef`.
Fixes issue #61981 by adjusting variable location offsets (in the DIExpression)
when splitting allocas.
Patch [4/4] to fix structured bindings in SROA.
NOTE: There's still a bug in mem2reg which generates incorrect locations in some
situations: if the variable fragment has an offset into the new (split) alloca,
mem2reg will fail to convert that into a bit shift (the location contains a
garbage offset). That's not addressed here.
insertNewDbgInst - Now takes the address-expression and FragmentInfo as
separate parameters because unlike dbg_declares dbg_assigns want those to go
to different places. dbg_assign records put the variable fragment info in the
value expression only (whereas dbg_declare has only one expression so puts it
there - ideally this information wouldn't live in DIExpression, but that's
another issue).
MigrateOne - Modified to correctly compute the necessary offsets and fragment
adjustments. The previous implementation produced bogus locations for variables
with non-zero offsets. The changes replace most of the body of this lambda, so
it might be easier to review in a split-diff view and focus on the change as a
whole than to compare it to the old implementation.
This uses calculateFragmentIntersect and extractLeadingOffset added in previous
patches in this series, and createOrReplaceFragment described below.
createOrReplaceFragment - Similar to DIExpression::createFragmentExpression
except for 3 important distinctions:
1. The new fragment isn't relative to an existing fragment.
2. There are no checks on the the operation types because it is assumed
the location this expression is computing is not implicit (i.e., it's
always safe to create a fragment because arithmetic operations apply
to the address computation, not to an implicit value computation).
3. Existing extract_bits are modified independetly of fragment changes
using \p BitExtractOffset. A change to the fragment offset or size
may affect a bit extract. But a bit extract offset can change
independently of the fragment dimensions.
Returns the new expression, or nullptr if one couldn't be created. Ideally
this is only used to signal that a bit-extract has become zero-sized (and thus
the new debug record has no size and can be dropped), however, it fails for
other reasons too - see the FIXME below.
FIXME: To keep the scope of this change focused on non-bitfield structured
bindings the function bails in situations that
DIExpression::createFragmentExpression fails. E.g. when fragment and bit
extract sizes differ. These limitations can be removed in the future.
If the instruction is marked for deletion, better to drop all its operands and mark them for deletion too (if allowed). It allows to have more vectorizable patterns and generate less useless extractelement instructions. Reviewers: RKSimon Reviewed By: RKSimon Pull Request: https://github.com/llvm/llvm-project/pull/97409
This patch makes the final major change of the RemoveDIs project, changing the default IR output from debug intrinsics to debug records. This is expected to break a large number of tests: every single one that tests for uses or declarations of debug intrinsics and does not explicitly disable writing records. If this patch has broken your downstream tests (or upstream tests on a configuration I wasn't able to run): 1. If you need to immediately unblock a build, pass `--write-experimental-debuginfo=false` to LLVM's option processing for all failing tests (remember to use `-mllvm` for clang/flang to forward arguments to LLVM). 2. For most test failures, the changes are trivial and mechanical, enough that they can be done by script; see the migration guide for a guide on how to do this: https://llvm.org/docs/RemoveDIsDebugInfo.html#test-updates 3. If any tests fail for reasons other than FileCheck check lines that need updating, such as assertion failures, that is most likely a real bug with this patch and should be reported as such. For more information, see the recent PSA: https://discourse.llvm.org/t/psa-ir-output-changing-from-debug-intrinsics-to-debug-records/79578
llvm.dbg.assign intrinsics have 2 {value, expression} pairs; fix hwasan to
update the second expression.
Fixes #76545. This is #78606 rebased and with the addition of DPValue handling.
Note the addition of --try-experimental-debuginfo-iterators in the tests and
some shuffling of code in MemoryTaggingSupport.cpp.