Researching in prep of doing the implementation for lowering, I found
that the source of the valid identifiers list from flang is in the
frontend. This patch adds the same list to the frontend, but does it as
a sema diagnostic, so we still parse it as an identifier/identifier-like
thing, but then diagnose it as invalid later.
OpenACC 3.3-NEXT has changed the way tags for copy, copyin, copyout, and
create clauses are specified, and end up adding a few extras, and
permits them as a list. This patch encodes these as bitmask enum so
they can be stored succinctly, but still diagnose reasonably.
OpenACC Github PR#499 defines the pqr-list as having at least 1 item. We
already handle that for all but 'wait', so this patch just does the work
to add it for 'wait', plus adds tests.
All 4 of the 'data' constructs have a requirement that at least 1 of a
small list of clauses must appear on the construct. This patch
implements that restriction, and updates all of the tests it takes to
do so.
This is a clause that is only valid on 'host_data' constructs, and
identifies variables which it should use the current device address.
From a Sema perspective, the only thing novel here is mild changes to
how ActOnVar works for this clause, else this is very much like the rest
of the 'var-list' clauses.
'delete' is another clause that has very little compile-time
implication, but needs a full AST that takes a var list. This patch
ipmlements it fully, plus adds sufficient test coverage.
This is another new clause specific to 'exit data' that takes a pointer
argument. This patch implements this the same way we do a few other
clauses (like attach) that have the same restrictions.
The 'if_present' clause controls the replacement of addresses in the
var-list in current device memory. This clause can only go on
'host_device'. From a Sema perspective, there isn't anything to do
beyond add this to AST and pass it on.
This is a very simple clause as far as sema is concerned. It is only
valid on 'exit data', and doesn't have any rules involving it, so it is
simply applied and passed onto the MLIR.
This is once again simply enabling this for 'data', 'enter data', and
'exit data' (and ensuring we error for 'host_data'). Implementation is
very simply to enable it rather than emit the not-implemented
diagnostic.
Semantically this is identical to all other constructs with this tag,
except in this case the 'wait' and 'async' are the only ones allowed
after it. This patch implements that rule using the existing
infrastructure.
These constructs are all very similar and closely related, so this patch
creates the AST nodes for them, serialization, printing/etc.
Additionally the restrictions are all added as tests/todos in the tests,
as those will have to be implemented once we get those clauses implemented.
