This allows us to check situations like this:
PAR i = 0 FOR 10
IF
i = 0
a[10] := 3
TRUE
a[i] := 3
Previously this would have been flagged unsafe (because 10 can overlap with 10 between the replicated branches).
But with this change, the equations on the replicators (including: i'>=i+1, i = 0, i' = 0) are included alongside 10=10, so there is no solution over all because the replicator equations prevent a solution (i.e. the 10 can't be used twice in parallel).
I also added an occam testcase to help time the different between * and TIMES. But gcc optimises out the loop with TIMES under -O2, and with -O0 there is a factor of four difference.
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 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.
This makes it possible to mark a slice as not needing runtime
checking, which is immediately useful for _sizes arrays.
This fixes cgtest03, which was previously failing to compile because
the _sizes array for one of the constants in it contained a runtime
check and thus wasn't itself constant. I've added a testcase file for
the relevant bit of code.
Unfortunately there appears to be exactly one place you can do this, and it
turns out to be inside inferTypes (because you need to know the type of c
completely, and you can't type-infer x until you know if it's a tag or a
variable). It's definitely nicer than doing it in the parser, though.
I've also started adding "-- AMBIGUITY" comments in the parser.
