Specifically, improved debug info retention in:
* tryReplaceRedundantInstructionPair,
* splitAggregateLoad,
* TempLValueElimination,
* Mem2Reg,
* ConstantFolding.
The changes to Mem2Reg allow debug info to be retained in the case tested by
self-nostorage.swift in -O builds, so we have just enabled -O in that file
instead of writing a new test for it.
We attempted to add a case to salvageDebugInfo for unchecked_enum_data, but it
caused crashes in Linux CI that we were not able to reproduce.
Previously debug info made not difference between an existential type and a
protocol type. This caused us to loose typealiases such as
typealias Alias = ProtocolType
in the debug info.
rdar://161134092
This showed up on and off again on the source-compatibility testsuite project hummingbird.
The gist of the problem is that transformations may not rewrite the
type of an inlined instance of a variable without also createing a
deep copy of the inlined function with a different name (and e.g., a
specialization suffix). Otherwise the modified inlined variable will
cause an inconsistency when later compiler passes try to create the
abstract declaration of that inlined function as there would be
conflicting declarations for that variable.
Since SILDebugScope isn't yet available in the SwiftCompilerSources
this fix just drop these variables, but it would be absolutely
possible to preserve them by using the same mechanism that SILCloner
uses to create a deep copy of the inlined function scopes.
rdar://163167975
This is necessary because we need to model its stack-allocation
behavior, although I'm not yet doing that in this patch because
StackNesting first needs to be taught to not try to move the
deallocation.
I'm not convinced that `async let` *should* be doing a stack allocation,
but it undoubtedly *is* doing a stack allocation, and until we have an
alternative to that, we will need to model it properly.
This new option allows the Driver to pass the path to a compilation
job's own binary swiftmodule artifact to the frontend. The compiler
then stores this path in the debug info, to allow clients like LLDB to
unambiguously know which binary Swift module belongs to which compile
unit.
rdar://163302154
This pass removes `copy_addr` instructions.
However, it has some problems which causes compiler crashes.
It's not worth fixing these bugs because
1. Most copy_addrs can be eliminated by TempRValueElimination and TempLValueElimination.
2. Once we have opaque value we don't need copy_addr elimination, anyway.
rdar://162212460
Missed this in my previous patch, avoid relying on the `in` location
for closures with parameters and capture lists. Instead, form scopes
that start at the first element of the body. This fixes a crasher
uncovered by the fuzzer.
inside function returning it
A stack overflow would happen when the compiler tried emitting debug
info for a function whose opaque return type was declared inside the
function itself. This fixes the issue by emitting a forward declaration
for the function before emitting it.
rdar://150313956
We sometimes mangle SILFunctionTypes when generating debug info
for reabstraction thunks, and these can have various exotic
parameter and result attributes. Two recent additions were
never plumbed through the mangler, causing assertion failures
when emitting debug info.
Fixes rdar://153730847.
* re-implement the pass in swift
* support alloc_stack liveranges which span over multiple basic blocks
* support `load`-`store` pairs, copying from the alloc_stack (in addition to `copy_addr`)
Those improvements help to reduce temporary stack allocations, especially for InlineArrays.
rdar://151606382
Introduce a new pass MandatoryTempRValueElimination, which works as the original TempRValueElimination, except that it does not remove any alloc_stack instruction which are associated with source variables.
Running this pass at Onone helps to reduce copies of large structs, e.g. InlineArrays or structs containing InlineArrays.
Copying large structs can be a performance problem, even at Onone.
rdar://151629149
