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 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.
This is looking at array dimensions in literals. By this point unknown
dimensions should have been inferred; if they haven't, I'd rather it blew up
here than caused bizarre behaviour later on.
(This is a good candidate for a property check.)
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.
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.
It wasn't looking for PROC definitions inside Specs. This is a good example of
a pass that really wants a trimmed "everywhere"/"contexts" rather than explicit
recursion.
This patch is actually an amalgam of multiple (already large) patches. Those patches conflicted (parameterised Structured vs. changes to usage checking and FlowGraph) and encountered a nasty bug in darcs 1 involving exponential time (see http://wiki.darcs.net/DarcsWiki/ConflictsFAQ for more details). Reasoning that half an hour (of 100% CPU use) was too long to apply patches, I opted to re-record the parameterised Structured changes as this new large patch. Here are the commit messages originally used for the patches (which, as mentioned, were already large patches):
A gigantic patch switching all the non-test modules over to using parameterised A.Structured
Changed the FlowGraph module again to handle any sort of Structured you want to pass to it (mainly for testing)
A further gigantic patch changing all the tests to work with the new parameterised Structured
Fixed a nasty bug involving functions being named incorrectly inside transformInputCase
Added a hand-written instance of Data for Structured that allows us to use ext1M properly
Fixed a few warnings in the code
This was not as straightforward as the C++ backend. CIF has no capability for supporting waiting *for* a specified time as an ALT guard; only waiting until (AFTER, in occam) a specified time. This is further complicated by the fact that when you disable an ALT timer guard in CIF, you have to be able to supply the timeout value that you waited on in the enable sequence.
Therefore, I added a pass that transforms all WaitFor guards into WaitUntil guards, by declaring nonce time variables, getting the time, and adding on the delay that we want to wait for; these actions occur just before the ALT.
This new pass is in the new BackendPasses module, into which I also moved the identifyParProcs pass. I also wrote tests for my new pass that live in the new BackendPassesTest module.
