Some reports weren’t announced last week, so there are multiple weeks covered below.
Lang
Full report 2016-05-13
Today we accepted three RFCs:
-
RFC #1358: Adding the
#[repr(align)] attribute. To avoid an incompatibility
case between gcc and msvc, we decided to disallow structs with a manual alignment
from being packed into another struct.
-
RFC #1592: An amendment to account for the WF requirement on tuples, which
was overlooked before.
-
RFC #1492: Allow
.. in more places within patterns.
We decided not to accept two RFCs as well. Both were dealing with some
details of how to handle intrinsics and atomic types. Given the recent
libs team decisions in
RFC 1543, the issue is
somewhat moot.
Full report 2016-05-20
We put one RFC into FCP:
-
RFC 1590: add the
lifetime fragment specifier
for macro_rules.
Compiler
Full report 2016-05-13
The compiler team has all gathered together at Mozilla’s offices in
Mountain View in the first ever “rustc development sprint”. We’ve been
hacking away on MIR support as well as incremental compilation, and
progress has been quite rapid. As of this writing, the hardest part of
the backend work on incremental compilation appears to be nearing
completion – restructuring the backend to create the reusable codegen
units. In MIR land, a number of optimization improvements have landed,
and there is even preliminary work on implementing
non-zeroing drop.
Finally, we’ve had a number of good architectural discussions.
Full report 2016-05-20
I mentioned that last week we had our first ever “compiler team
development sprint”. I wanted to give a few more details on what we
did during the week.
First off, we had a number of design discussions,
covering such topics as incremental compilation, the shortest path to
IDE integration, and how to restructure the compiler to move lifetime
checking so that it operates on the MIR (which is required for
non-lexical lifetimes).
Secondly, we did a lot of hacking! Some of the notable highlights were:
- arielb1 implemented a
more-or-less working version of non-zeroing drop!
- pnkfelix implemented a number of fixes and a unit-testing framework
for the dataflow framework that underlies the non-zeroing drop work.
- nagisa implemented a
lattice-based dataflow framework
for constant propagation and other optimizations on MIR.
- eddyb hacked up the compiler to
save metadata even when not generating code,
which could serve as the basis for a cross-crate version of
cargo check (think: very fast type-checking while you are
working). He also worked on some refactorings in support of incremental
compilation.
- nrc made a number of improvements to rustw, interfacing it to
the compiler’s metadata so it can support things like “go to
definition” etc. This will hopefully evolve into something that
other IDEs can tap into as well.
- mw and aatch made great progress on refactoring the back-end of the
compiler to be more suitable for incremental compilation; we’re
getting close to a working prototype!
- doener made a number of small improvements to MIR that collectively
had a huge impact on the time it takes to translate various crates
using MIR.
- nmatsakis (that’s me!) fixed a
horrible bug in the lifetime errors
that was often causing them to give terrible suggestions, and made some
improvements to track incremental changes across crates.
- Alon Zakai and Brian Anderson did some preliminary hacking that
allowed us to translate Rust MIR into
WebAssembly,
successfully converting a simple “hello, world” style example.
Quite a successful week!
Libs
Full report
This week we decided on API stabilizations for the 1.10 release:
We also discussed the policy around Rust compiler version support and
rust-lang crates, which resulted in a new
policy RFC.
Finally, this week saw a
major RFC covering the regex
crate, which will ultimately transition it to 1.0 and full rust-lang status.
Tools
Full report
- An excellent blog post about rustup was published, detailing the
vision for the tool and next steps.
- Custom panic runtimes are now implemented which means that the
compiler flag
-C panic=abort can now be use to implement panics as aborts.
- The new rust build system can now run crate tests which should
bring it up to feature parity for tier 1 platforms.
- Various Android targets have [seen][android1] [updates][android2] to enable
more features and align them with the upstream definitions.
- A new crate type,
cdylib, is now available for production by the
compiler which is optimized for producing a dynamic library with a C API.
More information can be found in the relevant RFC.
- Cargo will now retry failed network requests by default if they look
like they’re spurious failures.
- Cargo will now emit status to stderr instead of stdout.
