A check in trans didn't have a corresponding check in typeck, causing
some programs (to wit, compile-fail/chan-parameterized-args.rs - part of this
commit) to fail with an assertion failure in trans instead of a type error.
Fixed it. In short, arguments that are future thunk arguments (any spawn
arguments, and _ arguments in bind) need to either not contain type params
or type vars, or be by-reference.
Closes#665.
You can now say
expr_move(?dst, ?src) | expr_assign(?dst, ?src) { ... }
to match both expr_move and expr_assign. The names, types, and number
of bound names have to match in all the patterns.
Closes#449.
The alias rules guarantee that the alt-ed value will outlive the binding's
last use, so this is safe.
This is a preparation for or-patterns. Joining scoped bindings seems like
it would get messy.
Assignments and moves with a simple local variable reference on the
RHS now propagate any typestate constraints the RHS was involved
in to the LHS. Swaps where both sides are local variables
exchange the constraints.
This was a pain in the butt and I'm still not proud of the resulting
code. Needs refactoring like whoa.
trans::trans_lval will now autobind if the given expression was the
name of a generic functions. Those callees (trans_call and trans_bind)
that are interested in the generics information call trans_lval_gen
now.
Previously, we were creating both a normal vtable entry and a
forwarding function for overriding methods, when they should have just
gotten a vtable entry. This patch fixes that.
As a preparation for implementing the temporary-move optimization for
argument passing. The optimization itself isn't in yet, since it
mysteriously corrupts memory.
This adds support for dropping cleanups for temporary values when they
are moved somewhere else. It then adds wraps most copy operations
(return, put in data structure, box, etc) in a way that will fall back
to a move when it is safe.
This saves a lot of taking/dropping, shaving over a megabyte off the
stage2/rustc binary size.
In some cases, most notably function returns, we could detect that the
returned value is a local variable, and can thus be safely moved even
though it is not a temporary. This will require putting some more
information in lvals.
I did not yet handle function arguments, since the logic for passing
them looked too convoluted to touch. I'll probably try that in the
near future, since it's bound to be a big win.
