rust/compiler/rustc_mir_transform
bors c872a1418a Auto merge of #125507 - compiler-errors:type-length-limit, r=lcnr
Re-implement a type-size based limit

r? lcnr

This PR reintroduces the type length limit added in #37789, which was accidentally made practically useless by the caching changes to `Ty::walk` in #72412, which caused the `walk` function to no longer walk over identical elements.

Hitting this length limit is not fatal unless we are in codegen -- so it shouldn't affect passes like the mir inliner which creates potentially very large types (which we observed, for example, when the new trait solver compiles `itertools` in `--release` mode).

This also increases the type length limit from `1048576 == 2 ** 20` to `2 ** 24`, which covers all of the code that can be reached with craterbot-check. Individual crates can increase the length limit further if desired.

Perf regression is mild and I think we should accept it -- reinstating this limit is important for the new trait solver and to make sure we don't accidentally hit more type-size related regressions in the future.

Fixes #125460
2024-07-03 11:56:36 +00:00
..
src Auto merge of #125507 - compiler-errors:type-length-limit, r=lcnr 2024-07-03 11:56:36 +00:00
Cargo.toml compiler: const_eval/transform/validate.rs -> mir_transform/validate.rs 2024-05-24 09:56:56 -07:00
messages.ftl Remove MIR unsafe check 2024-04-03 08:50:12 +00:00