2019-04-18

Volunteers wanted

• No issues discussed this week.

Backport decisions

• There were no beta backport nominations this week.

• “Use informational target machine for metadata” (#58605) was nominated for backport to stable.

  • Nomination was declined

Working group sync

wg-llvm

• wg-llvm is working on optimizing overflow intrinsics with add and sub instructions.

• A PR (#59546) has also been opened to fix a long standing unsoundness issue. The PR is currently waiting for someone to run lolbench.rs to determine what impact the PR has on generated code performance.

Link to full discussion

wg-async-await

• wg-async-await is currently working though the list of issues blocking stabilization.

  • This includes:
    • Async-await syntax
    • Supporting async fns whose arguments have multiple lifetimes
    • Shrinking the size of generators

• The thorniest issue remaining is determining the drop order for unused async function arguments (#54716)

  • While investigating this issue, some subtle inconsistencies regarding existing drop order for regular functions were discovered.
  • This issue is also not proving to be easy to resolve.

Link to full discussion