This is matching the behavior of the rest of the verifier. NOTE: Both early exit
if said flag is not set, so this should not hit compile time in any way unless
the flag is set (in which case someone is asking for more verification...).
While I was here, I also noticed an ancillary bug where we were not checking if
a value was from in a block that was in a SILGlobalVariable or a SILFunction. We
already had a check that stopped this early when validating ownership of
SILInstructions. I guess we have never had a situation where the verifier was
given values to run on SILGlobalVariable blocks.
For some time now we have had the API ValueBase::getSingleUserOfType<T>() but we
never implemented getUsersOfType<T>() using transform/filter iterators.
Since there wasn't a specific API, several incarnations of this API have been
created for BeginBorrow, LoadBorrow, BeginAccess.
In this commit, I introduce the API and use it to excise the redundant code in
those above mentioned 3 instructions.
Specifically, we were preferring the always correct ownership kind specified by
the FunctionType and ignoring what we parsed from the argument. This PR changes
ossa to give a nice error when this is detected and fixes the places where this
tests were written incorrectly.
Add `llvm_unreachable` to mark covered switches which MSVC does not
analyze correctly and believes that there exists a path through the
function without a return value.
In a previous commit, I banned in the verifier any SILValue from producing
ValueOwnershipKind::Any in preparation for this.
This change arises out of discussions in between John, Andy, and I around
ValueOwnershipKind::Trivial. The specific realization was that this ownership
kind was an unnecessary conflation of the a type system idea (triviality) with
an ownership idea (@any, an ownership kind that is compatible with any other
ownership kind at value merge points and can only create). This caused the
ownership model to have to contort to handle the non-payloaded or trivial cases
of non-trivial enums. This is unnecessary if we just eliminate the any case and
in the verifier separately verify that trivial => @any (notice that we do not
verify that @any => trivial).
NOTE: This is technically an NFC intended change since I am just replacing
Trivial with Any. That is why if you look at the tests you will see that I
actually did not need to update anything except removing some @trivial ownership
since @any ownership is represented without writing @any in the parsed sil.
rdar://46294760
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
This matches the name of OperandOwnership.cpp which performs an anologous
function. I also was able to eliminate an unneeded header. The key thing here
is that the only reason that we had ValueOwnershipKindClassifier.h was because
we needed some defs from it in SILValue.cpp for SILValue::getOwnershipKind()
... which is great except for the fact that ValueOwnershipKindClassifier is
basically the implementation of SILValue::getOwnershipKind().
So what this patch does is moves the implementation of
SILValue::getOwnershipKind() from SILValue.cpp -> ValueOwnership.cpp and then
puts the visitor into an anonymous namespace in that file.
I also added a little comment in SILValue.h that says that
SILValue::getOwnershipKind() is implemented in ValueOwnership.cpp, not
SILValue.cpp.
In the new string implementation there is a subtract of a (small) constant from the literal pointer. We convert
((ptr - offset) | bits
to
(ptr + (bits - offset))
which can still be represented as a relocation.
NOTE: This is not the final form of how operand ownership restraints will be
represented. This patch is instead an incremental change that extracts out this
functionality from the ownership verifier as a pure refactor.
rdar://44667493
When compiling with MSVC on Windows, this error among other similar
conflicts with AnyValue occur:
Defined the overloads so it selects the correct one.
I hit this problem while splitting classifying operand ownership from the
ownership verifier itself. There is no reason to allow for this implicit
conversion. Just makes updating code more error prone.
rdar://44667493
I have a bunch of work that I have done on a side branch some time ago to split
determining what value ownership kinds are able to be associated with a specific
operand.
This PR just upstreams a small part of the larger change.
introduce a common superclass, SILNode.
This is in preparation for allowing instructions to have multiple
results. It is also a somewhat more elegant representation for
instructions that have zero results. Instructions that are known
to have exactly one result inherit from a class, SingleValueInstruction,
that subclasses both ValueBase and SILInstruction. Some care must be
taken when working with SILNode pointers and testing for equality;
please see the comment on SILNode for more information.
A number of SIL passes needed to be updated in order to handle this
new distinction between SIL values and SIL instructions.
Note that the SIL parser is now stricter about not trying to assign
a result value from an instruction (like 'return' or 'strong_retain')
that does not produce any.
We compile with a pedantic warning that complains about these things,
and the massive flood of warnings is actually causing problems for the
build infrastructure.
Looping over all users and returning the only user of a specific type is a
common pattern in the compiler. This method just allows for the loop to be
eliminated.
There are a few different use cases here:
1. In Raw SIL, no return folding may not have been run yet implying that a call
to a no-return function /can/ have arbitrary control flow after it (consider
mandatory inlined functions). We need to recognize that the region of code that
is strictly post dominated by the no-return function is "transitively
unreachable" and thus leaking is ok from that point. *Footnote 1*.
2. In Canonical and Raw SIL, we must recognize that unreachables and no-return
functions constitute places where we are allowed to leak.
rdar://29791263
----
*Footnote 1*: The reason why this is done is since we want to emit unreachable
code diagnostics when we run no-return folding. By leaving in the relevant code,
we have preserved all of the SILLocations on that code allowing us to create
really nice diagnostics.
Most of this involved sprinkling ValueOwnershipKind::Owned in many places. In
some of these places, I am sure I was too cavalier and I expect some of them to
be trivial. The verifier will help me to track those down.
On the other hand, I do expect there to be some places where we are willing to
accept guaranteed+trivial or owned+trivial. In those cases, I am going to
provide an aggregate ValueOwnershipKind that will then tell SILArgument that it
should disambiguate using the type. This will eliminate the ackwardness from
such code.
I am going to use a verifier to fix such cases.
This commit also begins the serialization of ValueOwnershipKind of arguments,
but does not implement parsing of value ownership kinds. That and undef are the
last places that we still use ValueOwnershipKind::Any.
rdar://29791263
