It looks like an apply of a partial_apply with an opened existential
in the substitutions triggered an assert because the opened
existential was not propagated into the body of the inlined
function.
Changes:
* Terminate all namespaces with the correct closing comment.
* Make sure argument names in comments match the corresponding parameter name.
* Remove redundant get() calls on smart pointers.
* Prefer using "override" or "final" instead of "virtual". Remove "virtual" where appropriate.
Applying nontrivial generic arguments to a nontrivial SIL layout requires lowered SILType substitution, which requires a SILModule. NFC yet, just an API change.
There's no longer a single element type to speak of. Update uses to either iterate all box fields or to assert that they're working with a single-field box.
This was made redundant by typed boxes, and the type operand was already removed from textual SIL, but the field was never removed from the instruction's in memory representation. It becomes wrong in the face of compound boxes with layout.
This was already done for getSuccessorBlocks() to distinguish getting successor
blocks from getting the full list of SILSuccessors via getSuccessors(). This
commit just makes all of the successor/predecessor code follow that naming
convention.
Some examples:
getSingleSuccessor() => getSingleSuccessorBlock().
isSuccessor() => isSuccessorBlock().
getPreds() => getPredecessorBlocks().
Really, IMO, we should consider renaming SILSuccessor to a more verbose name so
that it is clear that it is more of an internal detail of SILBasicBlock's
implementation rather than something that one should consider as apart of one's
mental model of the IR when one really wants to be thinking about predecessor
and successor blocks. But that is not what this commit is trying to change, it
is just trying to eliminate a bit of technical debt by making the naming
conventions here consistent.
Before this commit all code relating to handling arguments in SILBasicBlock had
somewhere in the name BB. This is redundant given that the class's name is
already SILBasicBlock. This commit drops those names.
Some examples:
getBBArg() => getArgument()
BBArgList => ArgumentList
bbarg_begin() => args_begin()
This eliminates all inline creation of SILBasicBlock via placement new.
There are a few reasons to do this:
1. A SILBasicBlock is always created with a parent function. This commit
formalizes this into the SILBasicBlock API by only allowing for SILFunctions to
create SILBasicBlocks. This is implemented via the type system by making all
SILBasicBlock constructors private. Since SILFunction is a friend of
SILBasicBlock, SILFunction can still create a SILBasicBlock without issue.
2. Since all SILBasicBlocks will be created in only a few functions, it becomes
very easy to determine using instruments the amount of memory being allocated
for SILBasicBlocks by simply inverting the call tree in Allocations.
With LTO+PGO, normal inlining can occur if profitable so there shouldn't be
overhead that we care about in shipping compilers.
This is working around an additional use-list DI ordering issue that I exposed
when implementing High Level Memory Operations. Specifically, DI started to
error on:
(class_method x)
instead of on:
(apply (class_method x) x)
We would also try to emit an error on the apply, but we would squelch the apply
error (which is more accuracte) since we had already emitted the class_method
error.
This commit conservatively checks for this condition and skips the class method
so we can emit the more descriptive error on the apply.
Often times SILGen wants to hold onto values that have been copied. This causes
an issue, when due to Cleanups firing, SILBuilder inserts destroys and destroys
the copy that produced the value that SILGen held onto. This will then cause
SILGen to emit incorrect code.
There really is no reason to introduce such complexity into SILBuilder when a
small simple guaranteed pass can perform the same work. Thus the introduction of
this pass.
In a later commit, I am going to eliminate the SILBuilder entry points.
rdar://28685236
Today, loads and stores are treated as having @unowned(unsafe) ownership
semantics. This leaves the user to specify ownership changes on the loaded or
stored value independently of the load/store by inserting ARC operations. With
the change to Semantic SIL, this will no longer be true. Instead loads, stores
have ownership semantics that one must reason about such as copy, take, and
trivial.
This change moves us closer to that world by eliminating the default
OwnershipQualification argument from create{Load,Store}. This means that the
compiler developer cannot ignore reasoning about the ownership semantics of the
memory operation that they are creating.
Operationally, this is a NFC change since I have just gone through the compiler
and updated all places where we create loads, stores to pass in the former
default argument ({Load,Store}OwnershipQualifier::Unqualified), to
SILBuilder::create{Load,Store}(...). For now, one can just do that in situations
where one needs to create loads/stores, but over time, I am going to tighten the
semantics up via the verifier.
rdar://28685236
This specific issue came up due to my SILGen changes for copy_value,
destroy_value. Specifically, we used to emit the diagnostic:
super.init isn't called on all paths before returning from initializer.
After my change, we began to emit:
'self' used before super.init call
Since the code was:
init() {}
there is clearly no use, so the new error is incorrect or at minimum
misleading. When I investigated why the change in diagnostic happened, it was
because as a result of my SILGen change, the order of the strong_retain and
return in the use-list swapped in the following code:
%1 = load %0 : $*MultipleInitDerived
strong_retain %1 : $MultipleInitDerived
return %1 : $MultipleInitDerived
Before my change, return was visited first, causing the correct diagnostic to be
emitted. After my change, the strong_retain is visited first causing the second
diagnostic to be emitted. Since we only emit one source error for each
SILLocation, in the 2nd case, the error associated with the return is not
emitted.
We should not be considering strong_retain to be a use that propagates
liveness. The reason why is that a strong_retain should always be paired with
some local use that consumes it, whether that is an apply, closure, or a store
into memory. Since we will always have a consuming operation for the retain and
the consuming operation actually is able to be something visible at the source
level to the user (versus the retain), it makes more sense to just ignore
strong_retain.
In general though, we should try to be more careful about how we swallow errors
in DI, especially in the light of use-list twiddling. I attempted to improve our
testing situation by added a flag '-definite-init-visit-debuginfo-locs' that
would cause DI to consider SIL Location debug info locs when deciding whether or
not to swallow errors. Sadly, our diagnostics (from what I can tell) do not
support emitting diagnositics for such locations, so I failed.
Thus I could not actually test this, but it will fail once I get in the
copy_value, destroy_value change, so that /should/ act as good enough of a test.
rdar://28851920
This is just old code that needs to be updated given changes in DebugInfo and
this should be a NFC change.
I am going to use this so that I can test a specific test case where DI emits
different errors depending on use-list ordering.
rdar://28851920
We don't want the machine calling conventions for closure invocation functions to necessarily be tied to the convention for normal thin functions or methods. NFC yet; for now, 'closure' follows the same behavior as the 'method' convention, but as part of partial_apply simplification it will be a requirement that partial_apply takes a @convention(closure) function and a box and produces a @convention(thick) function from them.
radar rdar://problem/28434323
SILGen has no reason to insert shadow copies for inout parameters any more. They cannot be captured. We still emit these copies. Sometimes deshadowing removes them, but sometimes it does not.
In this PR we just avoid emitting the copies and remove the deshadowing pass.
This PR chery-picked some of @dduan work and built on top of it.
When applying substitutions to substitution lists in SIL, we would
unpack the ArrayRef<Substitution> into a SubstitutionMap on each
iteration over the original ArrayRef<Substitution>. Discourage
this sort of thing by removing the API in question and refactoring
surrounding code.
Extend the checks in `LifetimeChecker` in
`SILOptimizer/Mandatory/DefiniteInitialization.cpp`
to catch when the memory object corresponding to a let constant is used
as an inout parameter in a protocol witness method.
Initializing a let constant separate from its declaration requires write
access. Therefore it is treated as `@lvalue TestProtocol` in the AST for
a certain scope.
Checking that the constant is not written to after being initialized is
supposed to happen in the Mandatory SILOptimizer phase instead.
On loads, the Optimizer checks, that a variable is fully initialized,
but perviously did not validate what happens to it after it is loaded.
This allowed loading the memory object through an open_existential_addr
instruction and applying the result as an Operand to a mutating witness
method.
This patch is rather large, since it was hard to make this change
incrementally, but most of the changes are mechanical.
Now that we have a lighter-weight data structure in the AST for mapping
interface types to archetypes and vice versa, use that in SIL instead of
a GenericParamList.
This means that when serializing a SILFunction body, we no longer need to
serialize references to archetypes from other modules.
Several methods used for forming substitutions can now be moved from
GenericParamList to GenericEnvironment.
Also, GenericParamList::cloneWithOuterParameters() and
GenericParamList::getEmpty() can now go away, since they were only used
when SILGen-ing witness thunks.
Finally, when printing generic parameters with identical names, the
SIL printer used to number them from highest depth to lowest, by
walking generic parameter lists starting with the innermost one.
Now, ambiguous generic parameters are numbered from lowest depth
to highest, by walking the generic signature, which means test
output in one of the SILGen tests has changed.
The inlining algorithm was rescanning the whole basic block after inlining a call, which resulted in O(N^2) time complexity. In some pathological cases like e.g. huge basic blocks with many thousands of calls this would lead to very long compile times which could takes hours to finish.
This change improves compile times by avoiding the rescanning of basic blocks containing the call which was inlined.
rdar://27818830
This function takes a substitution array and produces a
contextual type substitution map, so it is the contextual
type equivalent of GenericSignature::getSubstitutionMap(),
which produces an interface type substitution map.
The new version takes a GenericSignature, just like the new
getForwardingSubstitutions(), so that it can walk the
requirements of the signature rather than walking the
AllArchetypes list.
Also, this new version now produces a mapping from
archetypes to conformances in addition to the type mapping,
which will allow it to be used in a few places that had
hand-coded logic.
Turn on the noreturn diagnostic for cases where a reachable unreachable
could be encountered. Previously, the diagnostic would not fire if the
function was marked noreturn and any of its reachable unreachable calls
were around. While this makes sense from a SILGen perspective (it Just
Crashes tm), it is still wrong. We need to diagnose *everything* that
has reachable unreachables.
Previously, we were only able to detect factory initializers
dispatched through class_method. This didn't work for
factory initializers defined in protocol extensions.
The end result would be that we would strong_release an
uninitialized class instance, which could cause crashes.
Fix DI to correctly release the old instance using
dealloc_partial_ref instead.
Fixes <rdar://problem/27713221>.
Till now there was no way in SIL to explicitly express a dependency of an instruction on any opened archetypes used by it. This was a cause of many errors and correctness issues. In many cases the code was moved around without taking into account these dependencies, which resulted in breaking the invariant that any uses of an opened archetype should be dominated by the definition of this archetype.
This patch does the following:
- Map opened archetypes to the instructions defining them, i.e. to open_existential instructions.
- Introduce a helper class SILOpenedArchetypesTracker for creating and maintaining such mappings.
- Introduce a helper class SILOpenedArchetypesState for providing a read-only API for looking up available opened archetypes.
- Each SIL instruction which uses an opened archetype as a type gets an additional opened archetype operand representing a dependency of the instruction on this archetype. These opened archetypes operands are an in-memory representation. They are not serialized. Instead, they are re-constructed when reading binary or textual SIL files.
- SILVerifier was extended to conduct more thorough checks related to the usage of opened archetypes.
