Fix escaping inference var ICE in `point_at_expr_source_of_inferred_type` #107175

compiler-errors · 2023-01-21T22:24:55Z

point_at_expr_source_of_inferred_type uses lookup_probe to adjust the self type of a method receiver -- but that method returns inference variables from inside a probe. That means that the ty vars are no longer valid, so we can't use any infcx methods on them.

Also, pass some extra span info to hack a quick solution to bad labels, resulting in this diagnostic improvement:

fn example2() {
    let mut x = vec![1];
    x.push("");
}

  error[E0308]: mismatched types
   --> src/main.rs:5:12
    |
  5 |     x.push("");
    |       ---- ^^
    |       |    |
    |       |    expected integer, found `&str`
-   |       |    this is of type `&'static str`, which causes `x` to be inferred as `Vec<{integer}>`
    |       arguments to this method are incorrect

(since that "which causes x to be inferred as Vec<{integer}> part is wrong)

r? @estebank

(we really should make this code better in general, cc #106590, but that's a bit bigger issue that needs some more thinking about)

estebank · 2023-01-23T14:15:24Z

compiler/rustc_hir_typeck/src/demand.rs

+                    if !span.overlaps(mismatch_span) {
                    err.span_label(
                        span,
                        with_forced_trimmed_paths!(format!(
                            "here the type of `{ident}` is inferred to be `{ty}`",
                        )),
-                    );
+                    );}


Love let-chains 🙃

estebank · 2023-01-23T14:16:24Z

tests/ui/typeck/bad-type-in-vec-push.rs

@@ -0,0 +1,20 @@
+// The error message here still is pretty confusing.


We can probably check how many spans we have and if there's only one, with infer vars in the type, then we skip the customization? Not necessary for this PR.

estebank

r=me after fixing formatting

compiler-errors · 2023-01-23T17:21:40Z

@bors r=estebank

bors · 2023-01-23T17:21:43Z

📌 Commit 9f933b5 has been approved by estebank

It is now in the queue for this repository.

…ush, r=estebank Fix escaping inference var ICE in `point_at_expr_source_of_inferred_type` Fixes rust-lang#107158 `point_at_expr_source_of_inferred_type` uses `lookup_probe` to adjust the self type of a method receiver -- but that method returns inference variables from inside a probe. That means that the ty vars are no longer valid, so we can't use any infcx methods on them. Also, pass some extra span info to hack a quick solution to bad labels, resulting in this diagnostic improvement: ```rust fn example2() { let mut x = vec![1]; x.push(""); } ``` ```diff error[E0308]: mismatched types --> src/main.rs:5:12 | 5 | x.push(""); | ---- ^^ | | | | | expected integer, found `&str` - | | this is of type `&'static str`, which causes `x` to be inferred as `Vec<{integer}>` | arguments to this method are incorrect ``` (since that "which causes `x` to be inferred as `Vec<{integer}>` part is wrong) r? `@estebank` (we really should make this code better in general, cc rust-lang#106590, but that's a bit bigger issue that needs some more thinking about)

…ush, r=estebank Fix escaping inference var ICE in `point_at_expr_source_of_inferred_type` Fixes rust-lang#107158 `point_at_expr_source_of_inferred_type` uses `lookup_probe` to adjust the self type of a method receiver -- but that method returns inference variables from inside a probe. That means that the ty vars are no longer valid, so we can't use any infcx methods on them. Also, pass some extra span info to hack a quick solution to bad labels, resulting in this diagnostic improvement: ```rust fn example2() { let mut x = vec![1]; x.push(""); } ``` ```diff error[E0308]: mismatched types --> src/main.rs:5:12 | 5 | x.push(""); | ---- ^^ | | | | | expected integer, found `&str` - | | this is of type `&'static str`, which causes `x` to be inferred as `Vec<{integer}>` | arguments to this method are incorrect ``` (since that "which causes `x` to be inferred as `Vec<{integer}>` part is wrong) r? ``@estebank`` (we really should make this code better in general, cc rust-lang#106590, but that's a bit bigger issue that needs some more thinking about)

compiler-errors · 2023-01-26T03:24:07Z

@bors rollup as this only affects diagnostics

…iaskrgr Rollup of 11 pull requests Successful merges: - rust-lang#106407 (Improve proc macro attribute diagnostics) - rust-lang#106960 (Teach parser to understand fake anonymous enum syntax) - rust-lang#107085 (Custom MIR: Support binary and unary operations) - rust-lang#107086 (Print PID holding bootstrap build lock on Linux) - rust-lang#107175 (Fix escaping inference var ICE in `point_at_expr_source_of_inferred_type`) - rust-lang#107204 (suggest qualifying bare associated constants) - rust-lang#107248 (abi: add AddressSpace field to Primitive::Pointer ) - rust-lang#107272 (Implement ObjectSafe and WF in the new solver) - rust-lang#107285 (Implement `Generator` and `Future` in the new solver) - rust-lang#107286 (ICE in new solver if we see an inference variable) - rust-lang#107313 (Add Style Team Triagebot config) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup

rustbot assigned estebank Jan 21, 2023

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 Jan 21, 2023

estebank reviewed Jan 23, 2023

View reviewed changes

estebank approved these changes Jan 23, 2023

View reviewed changes

compiler-errors added 2 commits January 23, 2023 17:02

Don't resolve type var roots in point_at_expr_source_of_inferred_type

bed3bb5

Hack to suppress bad labels in type mismatch inference deduction code

9f933b5

compiler-errors force-pushed the bad-types-in-vec-push branch from 35ef3fc to 9f933b5 Compare January 23, 2023 17:03

bors 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 Jan 23, 2023

matthiaskrgr mentioned this pull request Jan 23, 2023

Rollup of 9 pull requests #107240

Closed

matthiaskrgr mentioned this pull request Jan 25, 2023

Rollup of 9 pull requests #107311

Closed

matthiaskrgr mentioned this pull request Jan 26, 2023

Rollup of 11 pull requests #107314

Merged

bors merged commit 5bc4980 into rust-lang:master Jan 26, 2023

rustbot added this to the 1.69.0 milestone Jan 26, 2023

compiler-errors mentioned this pull request Mar 3, 2023

Fix another ICE in point_at_expr_source_of_inferred_type #108667

Merged

compiler-errors deleted the bad-types-in-vec-push branch August 11, 2023 19:55

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Fix escaping inference var ICE in `point_at_expr_source_of_inferred_type` #107175

Fix escaping inference var ICE in `point_at_expr_source_of_inferred_type` #107175

compiler-errors commented Jan 21, 2023 •

edited

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estebank Jan 23, 2023

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bors commented Jan 23, 2023

compiler-errors commented Jan 26, 2023

		@@ -0,0 +1,20 @@
		// The error message here still is pretty confusing.

Fix escaping inference var ICE in point_at_expr_source_of_inferred_type #107175

Fix escaping inference var ICE in point_at_expr_source_of_inferred_type #107175

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compiler-errors commented Jan 23, 2023

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compiler-errors commented Jan 26, 2023

Fix escaping inference var ICE in `point_at_expr_source_of_inferred_type` #107175

Fix escaping inference var ICE in `point_at_expr_source_of_inferred_type` #107175

compiler-errors commented Jan 21, 2023 •

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