Ongoing projects

[wesleywiser]

This is a meta issue to track ongoing projects and other activities of the Incremental Compilation Working Group.

Talk to us on Zulip

Unless otherwise noted, consider any tasks "up for grabs".

Projects

• CGU Partitioning (Project: Code Gen Unit Partitioning #4)

  • @wesleywiser is taking point on this

• Better bug reporting for incremental issues (Project: Better bug reports for incremental issues #5)

  • @pnkfelix is taking point on this

Issues

• Treat inline functions the same as non-inline functions for debug builds (Make codegen treat inline fns the same as regular fns in non-opt builds rust#54089)

  • @spastorino is working on this
  • Related to the cgu partitioning work

• Special case non-inline functions to increase cgu granularity (incr. comp.: Increase partition granularity via special-casing non-inlined functions rust#35902)

  • Related to the cgu partitioning work

• Consider storing auto-generated error (panic) messages strings in a separate object file (Consider storing auto-generated error message strings in separate object file rust#37512)

  • Slightly related to the cgu partitioning work
  • Potential for code size improvements in addition to compilation time improvements.

• Optimize dependency-less anonymous queries (incr.comp.: Maybe optimize case of dependency-less anonymous queries. rust#45408)

  • This relates to the query system internals
  • Potential for small compile time improvements for both incremental and non-incremental cases.

• Don't create small cgus ([partitioning] Don't create CGUs below a certain size rust#47318)

  • Related to the cgu partitioning work

• Explore incremental linking (mentioned in Tracking Issue for Incremental Compilation rust#47660)

  • Needs design work and experimentation

• Add support for split debuginfo (debuginfo: Add support for split-debuginfo on platforms that allow it rust#34651)

  • Relates to LLVM and probably does not require changing much besides codegen

• Make the result cache updatable in place (incr.comp.: Investigate making the result cache updateable in-place. rust#48231)

  • Relates to the query system internals
  • Needs some investigation to prove there is a potential speedup

• Bug: Fix path canonicalization issues on Windows (Error when canonicalizing path on RAM drive rust#48249)

  • Relates to the query system internals
  • Worth some discussion but if the file system can't do what we're asking, it's probably fine to emit a warning and then disable incremental compilation

• Bug: Fix compilation aborted because it could not delete incremental files (Compiliation aborted because it can not delete dep-graph.bin rust#48614)

  • Relates to the query system internals
  • Worth discussion but if the file doesn't exist, we probably shouldn't error deleting it. It may also be ok to downgrade this to a warning (old incremental files should not cause an issue for the next compile)

Other Activities

• Bi-weekly update meetings, Tuesdays at 12:00 UTC on Zoom.