[dingxiangfei2009]

🐉 Highly experimental field projection primitive raw_handle!

r? @oli-obk

cc @ShaddyDC
cc @ojeda
cc @BennoLossin

We would like to submit this patch to start the experiment with the LocalHandle and PlaceHandle. We intend to continue polishing it in a patch series following this initial patch.

We know that the following items are not working.

• Closure capture is still hanging in the air, this will be another major work.
• Library trait wording. Field projection design in general is still shifting landscape, so many pieces as presented here would change. We will continue submitting patches to match the design.

[BennoLossin]

(a bit of context for Oli)

we disussed this PR in a meeting yesterday and I suggested we use a more concrete PlaceExpr type in the hir. Ding then argued that it would already make sense to do that in the ast, which I agree with. since that would be a bigger refactor, we figured we would just create the PR and then Ding (or Rasmus) change the ast to already use PlaceExpr in a few days when they find the time.

View changes since the review

[oli-obk]

Right. Yea I think it should def have more precise types here so you can only represent actually legal syntax.

It does mean you'll have to extend the visitors a bit, but it may suffice to just handle it in the walk functions without adding new visitor functions

[rust-log-analyzer]

The job test-aarch64-gnu-llvm-22-1 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

test [mir-opt] tests/mir-opt/unusual_item_types.rs ... ok

failures:

---- [mir-opt] tests/mir-opt/issues/issue_163598.rs stdout ----
24         _3 = &((*_1).0: T);
25         StorageLive(_4);
26         _4 = &((*_2).0: T);
-         _0 = <T as PartialOrd>::__chaining_le(move _3, move _4) -> [return: bb1, unwind unreachable];
+         _0 = <T as PartialOrd>::__chaining_le(move _3, move _4) -> [return: bb1, unwind continue];
28     }
29 
30     bb1: {

45         _6 = &((*_1).1: U);
46         StorageLive(_7);
47         _7 = &((*_2).1: U);
-         _0 = <U as PartialOrd>::__chaining_le(move _6, move _7) -> [return: bb4, unwind unreachable];
+         _0 = <U as PartialOrd>::__chaining_le(move _6, move _7) -> [return: bb4, unwind continue];
49     }
50 
51     bb4: {


thread '[mir-opt] tests/mir-opt/issues/issue_163598.rs' panicked at src/tools/compiletest/src/runtest/mir_opt.rs:73:21:
Actual MIR output differs from expected MIR output /checkout/tests/mir-opt/issues/issue_163598.chain_generic.runtime-optimized.after.mir
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
---- [mir-opt] tests/mir-opt/issues/issue_163598.rs stdout end ----

failures:
    [mir-opt] tests/mir-opt/issues/issue_163598.rs

[rust-bors]

☔ The latest upstream changes (presumably #164673) made this pull request unmergeable. Please resolve the merge conflicts by rebasing.