fix borrowck ICE for consts with fn pointer type by im-lunex · Pull Request #160314 · rust-lang/rust

im-lunex · 2026-08-01T04:47:22Z

borrowck's annotate_argument_and_return_for_borrow called tcx.fn_sig on the item being checked whenever its type was a fn def or fn ptr. For a const like const A: fn(), that asks for the signature of the const itself, which is not a function item, so we ICE'd with "unexpected sort of node in fn_sig".

Now we take the signature from the fn ptr type instead and skip the annotation when there's no fn decl to annotate.

also added a regression test under tests/ui/borrowck.

fixes: #160255

rustbot · 2026-08-01T04:47:26Z

Thanks for the pull request, and welcome! The Rust Project is excited to review your changes, and you should hear from @davidtwco (or someone else) some time within the next two weeks.

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TaKO8Ki · 2026-08-01T10:44:21Z

r? TaKO8Ki

TaKO8Ki

Thanks for working on this. For future contributions, please check whether an issue is already assigned or someone has started working on it before opening a PR. I had assigned 160255 to myself and had already begun preparing a fix, so this duplicated ongoing work. If an issue is already assigned, please ask the assignee before starting work on it.

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rustbot · 2026-08-01T10:50:40Z

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

TaKO8Ki · 2026-08-01T19:11:57Z

@bors squash

* fix borrowck ICE for consts with fn pointer type annotate_argument_and_return_for_borrow called tcx.fn_sig on the item being checked whenever its type was FnDef or FnPtr. for a const whose type is a fn pointer that's not a function item, so we ICE'd with "unexpected sort of node in fn_sig". take the signature from the fn ptr type instead and skip the annotation when there's no fn decl. * run rustfmt and refmt * fix borrowck ICE for consts with fn pointer type annotate_argument_and_return_for_borrow called tcx.fn_sig on the item being checked whenever its type was FnDef or FnPtr. for a const whose type is a fn pointer that's not a function item, so we ICE'd with "unexpected sort of node in fn_sig". take the signature from the fn ptr type instead and skip the annotation when there's no fn decl. * edit comment * use ty.fn_sig per review

rust-bors · 2026-08-01T19:12:19Z

🔨 5 commits were squashed into d443d45.

im-lunex · 2026-08-02T06:08:28Z

@rustbot ready

TaKO8Ki

Thanks.

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TaKO8Ki · 2026-08-03T06:22:55Z

@bors r+ rollup

rust-bors · 2026-08-03T06:22:58Z

📌 Commit d443d45 has been approved by TaKO8Ki

It is now in the queue for this repository.

🌲 The tree is currently closed for pull requests below priority 5. This pull request will be tested once the tree is reopened.

Reason for tree closure: spurious failures

fix borrowck ICE for consts with fn pointer type `borrowck`'s `annotate_argument_and_return_for_borrow` called `tcx.fn_sig` on the item being checked whenever its type was a `fn def` or `fn ptr`. For a const like `const A: fn()`, that asks for the signature of the const itself, which is not a function item, so we ICE'd with `"unexpected sort of node in fn_sig"`. Now we take the signature from the `fn ptr` type instead and skip the annotation when there's no `fn decl` to annotate. also added a regression test under `tests/ui/borrowck`. fixes: rust-lang#160255

…uwer Rollup of 6 pull requests Successful merges: - #159844 (Subtree cg_gcc sync (2026-07-24)) - #160406 (`DepKind` cleanups) - #159303 (Fix ICE for direct inline const generic defaults) - #160314 (fix borrowck ICE for consts with fn pointer type) - #160322 (ElaborateBoxDeref: remove unnecessary projection) - #160384 (Add PR body notes for Cargo lock file maintenance)

fix borrowck ICE for consts with fn pointer type `borrowck`'s `annotate_argument_and_return_for_borrow` called `tcx.fn_sig` on the item being checked whenever its type was a `fn def` or `fn ptr`. For a const like `const A: fn()`, that asks for the signature of the const itself, which is not a function item, so we ICE'd with `"unexpected sort of node in fn_sig"`. Now we take the signature from the `fn ptr` type instead and skip the annotation when there's no `fn decl` to annotate. also added a regression test under `tests/ui/borrowck`. fixes: rust-lang#160255

…uwer Rollup of 21 pull requests Successful merges: - #159844 (Subtree cg_gcc sync (2026-07-24)) - #159326 (Deny multiple EII impls on a single item) - #159535 (Optimize slice::contains for bytewise types) - #159595 (Promote loongarch32-unknown-none* to Tier 2) - #160007 (allow `-Ldependency` search paths for panic runtimes) - #160320 (point at trait definition when it is used as a derive macro) - #160369 (When suggesting method names, prefer *exact* doc aliases over similar names) - #160406 (`DepKind` cleanups) - #160424 (Use `thread::available_parallelism` as the default limit for backend parallelism) - #159014 ([rustdoc] Do not take `doc(cfg())` into account when filtering doctests) - #159303 (Fix ICE for direct inline const generic defaults) - #159977 (Add regression test for bool indexing codegen) - #160165 (reject `...` without pattern post-expansion) - #160295 (Fix rustdoc ICE when checking if a generic arg can be elided) - #160305 (Linkify C-SKY targets in `platform-support.md`) - #160314 (fix borrowck ICE for consts with fn pointer type) - #160322 (ElaborateBoxDeref: remove unnecessary projection) - #160338 (Add regression test for supertrait associated type normalization through dyn) - #160340 (Add regression test for unused_parens on contract clauses) - #160371 (Add doc aliases for transpositions `read_exact_buf` and `read_exact_buf_at`) - #160384 (Add PR body notes for Cargo lock file maintenance)

fix borrowck ICE for consts with fn pointer type `borrowck`'s `annotate_argument_and_return_for_borrow` called `tcx.fn_sig` on the item being checked whenever its type was a `fn def` or `fn ptr`. For a const like `const A: fn()`, that asks for the signature of the const itself, which is not a function item, so we ICE'd with `"unexpected sort of node in fn_sig"`. Now we take the signature from the `fn ptr` type instead and skip the annotation when there's no `fn decl` to annotate. also added a regression test under `tests/ui/borrowck`. fixes: rust-lang#160255

…uwer Rollup of 23 pull requests Successful merges: - #153749 (Account for ownership mismatch on argument that doesn't meet bound) - #159326 (Deny multiple EII impls on a single item) - #159535 (Optimize slice::contains for bytewise types) - #159595 (Promote loongarch32-unknown-none* to Tier 2) - #160007 (allow `-Ldependency` search paths for panic runtimes) - #160184 (Add -Zinstrument-mcount={fentry-nop-record,fentry-record}) - #160320 (point at trait definition when it is used as a derive macro) - #160369 (When suggesting method names, prefer *exact* doc aliases over similar names) - #160406 (`DepKind` cleanups) - #160424 (Use `thread::available_parallelism` as the default limit for backend parallelism) - #159303 (Fix ICE for direct inline const generic defaults) - #159977 (Add regression test for bool indexing codegen) - #160011 (remove InterpError::map_err_info) - #160165 (reject `...` without pattern post-expansion) - #160295 (Fix rustdoc ICE when checking if a generic arg can be elided) - #160305 (Linkify C-SKY targets in `platform-support.md`) - #160314 (fix borrowck ICE for consts with fn pointer type) - #160322 (ElaborateBoxDeref: remove unnecessary projection) - #160338 (Add regression test for supertrait associated type normalization through dyn) - #160340 (Add regression test for unused_parens on contract clauses) - #160371 (Add doc aliases for transpositions `read_exact_buf` and `read_exact_buf_at`) - #160384 (Add PR body notes for Cargo lock file maintenance) - #160435 (bump tracing-tree)

fix borrowck ICE for consts with fn pointer type `borrowck`'s `annotate_argument_and_return_for_borrow` called `tcx.fn_sig` on the item being checked whenever its type was a `fn def` or `fn ptr`. For a const like `const A: fn()`, that asks for the signature of the const itself, which is not a function item, so we ICE'd with `"unexpected sort of node in fn_sig"`. Now we take the signature from the `fn ptr` type instead and skip the annotation when there's no `fn decl` to annotate. also added a regression test under `tests/ui/borrowck`. fixes: rust-lang#160255

rustbot assigned davidtwco Aug 1, 2026

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Aug 1, 2026

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rustbot assigned TaKO8Ki and unassigned davidtwco Aug 1, 2026

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Comment thread tests/ui/borrowck/const-fn-ptr-borrow-annotation.rs Outdated

rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Aug 1, 2026

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Comment thread compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs Outdated

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rust-bors Bot force-pushed the fix_#160255 branch from f6974e6 to d443d45 Compare August 1, 2026 19:12

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Aug 2, 2026

im-lunex requested a review from TaKO8Ki August 2, 2026 11:31

TaKO8Ki approved these changes Aug 3, 2026

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rust-bors Bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Aug 3, 2026

JonathanBrouwer mentioned this pull request Aug 3, 2026

Rollup of 4 pull requests #160419

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JonathanBrouwer mentioned this pull request Aug 3, 2026

Rollup of 6 pull requests #160423

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JonathanBrouwer mentioned this pull request Aug 3, 2026

Rollup of 21 pull requests #160437

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JonathanBrouwer mentioned this pull request Aug 3, 2026

Rollup of 23 pull requests #160455

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JonathanBrouwer mentioned this pull request Aug 3, 2026

Rollup of 26 pull requests #160469

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