For some reason, the usage check tests are now very slow to run (perhaps because of all the operator definitions added to each one?), which needs further investigation.
This may seem like an odd change, but it simplifies the logic a lot. I kept having problems with passes not operating on externals (e.g. functions-to-procs, adding array sizes, constant folding in array dimensions) and adding a special case every time to also process the externals was getting silly.
Putting the externals in the AST therefore made sense, but I didn't want to just add dummy bodies as this would cause them to throw up errors (e.g. in the type-checking for functions). So I turned the bodies into a Maybe type, and that has worked out well.
I also stopped storing the formals in csExternals (since they are now in csNames, and the tree), which streamlined that nicely, and stopped me having to keep them up to date.
I changed a little bit of the code, but mainly the tests. Several of the remaining failures are actually real failures, so I need to dig through the rest carefully. A lot are failing because the C++ backend is broken.
All the passes now have their information (name, pre-requisites and post- properties) stored at the point where the pass is declared, which means the pass lists are just a simple list of pass functions.
The main consequence of this change was that the tests had to be changed. Now, instead of taking a "pass applied to data" item (type: PassM b), they take both the pass (type: Pass) and source data (type: b), and apply them later. This was the decision that involved the simplest changes to the existing tests (simply unbracketing the application of the pass to the source). I also had to include a few old-style versions though (testPass', testPassShouldFail') for where the functions were being used to test things that weren't actually passes (mainly StructureOccam).
Fixes#48
NameType is only really needed in the parser, so this takes it out of
NameDef, meaning that later passes defining names no longer need to
set an arbitrary NameType for them. The parser gets slightly more
complicated (because some productions now have to return a SpecType
and a NameType too), but lots of other code gets simpler.
The code that removed free names was the only thing outside the parser
using NameType, and it now makes a more sensible decision based on the
SpecType. Since unscoped names previously didn't have a SpecType at
all, I've added an Unscoped constructor to it and arranged matters
such that unscoped names now get a proper entry in csNames.
Fixes#61.
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 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
