This changes the Traversal API to the one that I've been working on in
the Polyplate branch, but implemented in terms of Data. The
performance isn't as good as the Polyplate version, but the code is a
lot simpler because it doesn't need all the type constraints (and it
doesn't make GHC struggle).
This also reworks all the passes in Tock to use the new API, including
those that previously used makeGeneric (which I've now removed) or
everywhereM. Most of the passes are simpler because of this, and I
suspect it's fixed a few subtle bugs resulting from missing recursion
in makeGeneric code.
I haven't yet profiled this, but subjectively it seems about the same
as the old Traversal (and thus faster for all the passes that didn't
yet use it).
This fixes Trac ticket #46. The pass for masking out state bodies has been moved to PassList (since it's so small and should be run first) for now, and SimplifyTypes has had its previous two passes merged into one.
This patch hides all the old typeOfExpression, typeOfName, typeOfVariable, etc, and unifies them into a single type-class with an "astTypeOf" function. The type-class is currently named Typed, but that can easily be changed (it's only explicitly referred to in the Types module). The patch is essentially the type-class with a giant find-and-replace on the other modules.
It's redundant, since you can always compute them from the variable, and it
makes the code that deals with actuals rather cleaner.
On the other hand, it slightly complicates some of the tests, because any names
you use in an Actual need to be defined...
This touches an awful lot of code, but cgtest07/17 (arrays and retyping) pass.
This is useful because there are going to be places in the future where we'll
want to represent dimensions that are known at runtime but not at compile time
-- for example, mobile allocations, or dynamically-sized arrays. It simplifies
the code in a number of places.
However, we do now need to be careful that expressions containing variables do
not leak into the State, since they won't be affected by later passes.
Two caveats (marked as FIXMEs in the source):
- Retypes checking in the occam parser is disabled, since the plan is to move
it out to a pass anyway.
- There's some (now very obvious) duplication, particularly in the backend, of
bits of code that construct expressions for the total size of an array
(either in bytes or elements); this should be moved to a couple of helper
functions that everything can use.
This lets you say things like:
VAL []INT xs IS [i = 0 FOR 20 | i]:
and have it figure out that the type of xs is really [20]INT.
This also cleans up the code a very small amount.
All it did was to make a list of the Procs generated by parsToProcs, so
parsToProcs may as well just do the same job itself.
The reason I'd made it a separate pass originally was that I wanted to
optimise out the wrapper when the child of a Par was already a ProcCall.
That optimisation isn't going to be possible any more with the new CCSP,
since wrappers have to fetch their arguments in a different way from
ordinary Procs.
Previously, assignments of records were directly flattened into assignment of each of the fields. Now, we instead generate a copy_<recordname> inline procedure for each record definition, and compile code that uses that (for C++, we could even make this an operator= implementation later on). This allows us to re-use the proc later in the C/C++ backends if needed.