Rename various resolving functions for consistency, and document them

[jdonszelmann]

r? @lcnr or anyone in @rust-lang/initiative-trait-system-refactor

This is all changes from https://github.com/rust-lang/rust/pull/160913/changes that are just renames. Updating that PR to be just the logic changes

All interesting changes happened in rustc_infer/src/infer/mod.rs across all commits. Everything else is renames propagating through other files.

The functions are now called:

before	after	note
shallow_resolve_*	(unchanged) shallow_resolve_*	Now with newly added docs.
resolve_vars_if_possible_*	deeply_resolve_ignoring_regions_*	deliberately longer name, we want to encourage using deeply_resolve instead.
eager_resolve_vars	deeply_resolve	moved onto the InferCtxtLike as an inherent method with default body.
fully_resolve	(unchanged) deeply_resolve_and_assert_fully_resolved	Resolves with regions and asserts that all variables are resolved at the end. Note, we only use this function 3x so the long name is ok, it shouldn't be your go-to anyway.
opportunistic_resolve_var		gone, same as shalllow_resolve now that we resolve to roots

Note

I've not used an LLM for any part of this PR, or any other PR I make. This includes any related work like research.

[rustbot]

changes to inspect_obligations.rs

cc @lcnr

changes to the core type system

cc @lcnr

Some changes occurred to the core trait solver

cc @rust-lang/initiative-trait-system-refactor

Some changes occurred in need_type_info.rs

cc @lcnr

[BoxyUwU]

bikeshed: fully_resolve to deeply_resolve_and_assert_blah or sth? it feels odd to me that there wouldnt be a naming similarity between fully_resolve and all the other methods

[jdonszelmann]

hm, I do like that, lemme change that @BoxyUwU :)

[BoxyUwU]

Seems reasonable enough 🤔 It feels a little unfortunate that we lose "var" being in the name of resolve_vars_if_possible. It's also a little unfortunate that deeply_resolve has naming similarities with deeply_normalize which errors if it can't normalize sth, whereas deeply_normalize is fine if it can't resolve something 🤔

I do like the new names more though since they feel more internally consistent with eachother

View changes since this review

[BoxyUwU]

@rustbot author (conflicts)

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[jdonszelmann]

@rustbot review

[rust-log-analyzer]

The job test-pr-check-2 failed! Check out the build log: (web) (plain enhanced) (plain)

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

 Documenting rustc_infer v0.0.0 (/checkout/compiler/rustc_infer)
warning: unresolved link to `rustc_type_ir::deeply_resolve`
    --> compiler/rustc_infer/src/infer/mod.rs:1268:38
     |
1268 |     /// or better [`deeply_resolve`](rustc_type_ir::deeply_resolve), if you can, which *does* resolve regions.
     |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `deeply_resolve` in module `rustc_type_ir`
     |
     = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

 Documenting rustc_symbol_mangling v0.0.0 (/checkout/compiler/rustc_symbol_mangling)
 Documenting rustc_public_bridge v0.0.0 (/checkout/compiler/rustc_public_bridge)
 Documenting rustc_ty_walk v0.0.0 (/checkout/compiler/rustc_ty_walk)
error: `rustc_infer` (lib doc) generated 1 warning
error: warnings are denied by `build.warnings` configuration
warning: build failed, waiting for other jobs to finish...
Command `/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo doc --target x86_64-unknown-linux-gnu -Zbinary-dep-depinfo -j 4 -Zroot-dir=/checkout -Zembed-metadata=no --locked --color=always --profile=release --features 'llvm rustc' --manifest-path /checkout/compiler/rustc/Cargo.toml -Zskip-rustdoc-fingerprint --no-deps -Zrustdoc-map -p rustc-main -p rustc_abi -p rustc_arena -p rustc_ast -p rustc_ast_ir -p rustc_ast_lowering -p rustc_ast_passes -p rustc_ast_pretty -p rustc_attr_ir -p rustc_attr_parsing -p rustc_baked_icu_data -p rustc_borrowck -p rustc_builtin_macros -p rustc_codegen_llvm -p rustc_codegen_ssa -p rustc_const_eval -p rustc_crate_store -p rustc_data_structures -p rustc_driver -p rustc_driver_impl -p rustc_error_codes -p rustc_error_messages -p rustc_errors -p rustc_expand -p rustc_expand_queries -p rustc_feature -p rustc_fs_util -p rustc_graphviz -p rustc_hashes -p rustc_hir -p rustc_hir_analysis -p rustc_hir_id -p rustc_hir_pretty -p rustc_hir_typeck -p rustc_incremental -p rustc_index -p rustc_index_macros -p rustc_infer -p rustc_interface -p rustc_lexer -p rustc_lint -p rustc_lint_defs -p rustc_llvm -p rustc_log -p rustc_macros -p rustc_metadata -p rustc_middle -p rustc_mir_build -p rustc_mir_dataflow -p rustc_mir_transform -p rustc_monomorphize -p rustc_next_trait_solver -p rustc_parse -p rustc_parse_format -p rustc_passes -p rustc_pattern_analysis -p rustc_privacy -p rustc_proc_macro -p rustc_public -p rustc_public_bridge -p rustc_query_impl -p rustc_resolve -p rustc_sanitizers -p rustc_serialize -p rustc_session -p rustc_span -p rustc_structures -p rustc_symbol_mangling -p rustc_target -p rustc_thread_pool -p rustc_trait_selection -p rustc_traits -p rustc_transmute -p rustc_ty_utils -p rustc_ty_walk -p rustc_type_ir -p rustc_type_ir_macros -p rustc_windows_rc [workdir=/checkout]` failed with exit code 101
Created at: src/bootstrap/src/core/build_steps/doc.rs:946:25
Executed at: src/bootstrap/src/core/build_steps/doc.rs:1007:26

Command has failed. Rerun with -v to see more details.
Bootstrap failed while executing `doc compiler --stage 1`
Currently active steps:
doc::Rustc { build_compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu, crates: ["rustc-main", "rustc_abi", "rustc_arena", "rustc_ast", "rustc_ast_ir", "rustc_ast_lowering", "rustc_ast_passes", "rustc_ast_pretty", "rustc_attr_ir", "rustc_attr_parsing", "rustc_baked_icu_data", "rustc_borrowck", "rustc_builtin_macros", "rustc_codegen_llvm", "rustc_codegen_ssa", "rustc_const_eval", "rustc_crate_store", "rustc_data_structures", "rustc_driver", "rustc_driver_impl", "rustc_error_codes", "rustc_error_messages", "rustc_errors", "rustc_expand", "rustc_expand_queries", "rustc_feature", "rustc_fs_util", "rustc_graphviz", "rustc_hashes", "rustc_hir", "rustc_hir_analysis", "rustc_hir_id", "rustc_hir_pretty", "rustc_hir_typeck", "rustc_incremental", "rustc_index", "rustc_index_macros", "rustc_infer", "rustc_interface", "rustc_lexer", "rustc_lint", "rustc_lint_defs", "rustc_llvm", "rustc_log", "rustc_macros", "rustc_metadata", "rustc_middle", "rustc_mir_build", "rustc_mir_dataflow", "rustc_mir_transform", "rustc_monomorphize", "rustc_next_trait_solver", "rustc_parse", "rustc_parse_format", "rustc_passes", "rustc_pattern_analysis", "rustc_privacy", "rustc_proc_macro", "rustc_public", "rustc_public_bridge", "rustc_query_impl", "rustc_resolve", "rustc_sanitizers", "rustc_serialize", "rustc_session", "rustc_span", "rustc_structures", "rustc_symbol_mangling", "rustc_target", "rustc_thread_pool", "rustc_trait_selection", "rustc_traits", "rustc_transmute", "rustc_ty_utils", "rustc_ty_walk", "rustc_type_ir", "rustc_type_ir_macros", "rustc_windows_rc"] } at src/bootstrap/src/core/build_steps/doc.rs:916
Build completed unsuccessfully in 0:02:11
  local time: Tue Sep  8 14:34:32 UTC 2026