This lets you write things like "[cs! FOR 5]", which is horrible; I
would prefer "[cs FOR 5]!", since then that doesn't imply that you can
do things like "cs![0] ! 0".
However, Tock now compiles and passes cgtest87 -- the first occam-pi
cgtest we've handled. :)
This is mostly straightforward: modify the parser to allow direction
decorators in the right places, and extend the type checker to match.
There's some slight awkwardness in that some of the Types functions
have to perform the same checks as the type checker (e.g. directing a
non-channel), so I've tidied up their error messages a bit.
At the backend, I've just added a little pass to strip out all the
DirectedVariables, since the other backend passes don't handle them
gracefully. From the occam/C point of view this is fine, but I'm not
sure if it's going to cause problems for C++.
This also refactors the sizes-array-declaring code, pulling the
declaration of static sizes out to a helper function, and does a
couple of other minor cleanups to match.
I'm pretty sure this test used to fail and got fixed, but I think the
test was fixed to match the incorrect code rather than the other way
around. What it's testing is the abbreviation of a channel end as an
identically-typed channel end, which (since they're both pointers)
should look something like:
Channel *c;
Channel *d = c;
Instead it was generating "d = &c", which broke cgtest87.
The change made to GenerateC to fix this feels a bit awkward to me --
it's very simple, but it's yet another special case in genVariableAM.
All of the genVariable code could really use reworking (again),
perhaps to use some internal representation of the C expression...
The expressions are optional (wrapped in a Maybe type). Nothing indicates that the variable was written to, but that the value isn't available. This is usually the case (for example, process parameters, channel inputs).
I have also temporarily disabled the tests for this function
Previously it was a tuple, which meant it couldn't have sensible
custom instances. Token and TokenType now have Show instances, so we
get more useful output when parsing fails.
This fixes the AST, parser and typechecker, and adds a pass to
transform Result back into Abbrev, but doesn't transform Initial yet.
(It actually works for trivial stuff anyway, but it won't do the right
thing for complex types or PROC parameters.)
It appears (to me) to make sense to support INITIAL/RESULT reshaping
and retyping too, so this does.
Refs #42.
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
