The pipes compiler produced data types that encoded efficient and safe
bounded message passing protocols between two endpoints. It was also
capable of producing unbounded protocols.
It was useful research but was arguably done before its proper time.
I am removing it for the following reasons:
* In practice we used it only for producing the `oneshot` and `stream`
unbounded protocols and all communication in Rust use those.
* The interface between the proto! macro and the standard library
has a large surface area and was difficult to maintain through
language and library changes.
* It is now written in an old dialect of Rust and generates code
which would likely be considered non-idiomatic.
* Both the compiler and the runtime are difficult to understand,
and likewise the relationship between the generated code and
the library is hard to understand. Debugging is difficult.
* The new scheduler implements `stream` and `oneshot` by hand
in a way that will be significantly easier to maintain.
This shouldn't be taken as an indication that 'channel protocols'
for Rust are not worth pursuing again in the future.
Hello,
While looking at `tests.mk` I noticed two errors:
- there's a `srcrustllvm` instead of `src/rustllvm`
- some filtered out files don't exist anymore
These two commits fix these issues. Thanks!
Change the former repetition::
for 5.times { }
to::
do 5.times { }
.times() cannot be broken with `break` or `return` anymore; for those
cases, use a numerical range loop instead.
Change all users of old-style for with internal iterators to using
`do`-loops.
The code in stackwalk.rs does not actually implement the
looping protocol (no break on return false).
The code in gc.rs does not use loop breaks, nor does any code using it.
We remove the capacity to break from the loops in std::gc and implement
the walks using `do { .. }` expressions.
No behavior change.
.intersection(), .union() etc methods in trait std::container::Set use
internal iters. Remove these methods from the trait.
I reported issue #8154 for the reinstatement of iterator-based set algebra
methods to the Set trait.
For bitv and treemap, that lack Iterator implementations of set
operations, preserve them as methods directly on the types themselves.
For HashSet, these methods are replaced by the present .union_iter()
etc.
* All globals marked as `pub` won't have the `internal` linkage type set
* All global references across crates are forced to use the address of the
global in the other crate via an external reference.
Assertions without a message get a generated message that consists of a
prefix plus the stringified expression that is being asserted. That
prefix is currently a unique string, while a static string would be
sufficient and needs less code.
Builds are considerably faster without assertions, so when working on
e.g. libstd, which doesn't directly interact with LLVM, one might want
to disable them.
This is a preliminary implementation of `for ... in ... { ...}` using a transitionary keyword `foreach`. Codesize seems to be a little bit down (10% or less non-opt) and otherwise it seems quite trivial to rewrite lambda-based loops to use it. Once we've rewritten the codebase away from lambda-based `for` we can retarget that word at the same production, snapshot, rewrite the keywords in one go, and expire `foreach`.
Feedback welcome. It's a desugaring-based approach which is arguably something we should have been doing for other constructs before. I apologize both for the laziness associated with doing it this way and with any sense that I'm bending rules I put in place previously concerning "never doing desugarings". I put the expansion in `expand.rs` and would be amenable to the argument that the code there needs better factoring / more helpers / to move to a submodule or helper function. It does seem to work at this point, though, and I gather we'd like to get the shift done relatively quickly.
