[VibhuGupta-dev]

Fixes #164592

E0117 used the whole impl header (tcx.def_span(impl_def_id)) as its
primary span, while the labels point at the trait path and the self type,
both of which sit inside that header. These overlapping spans render as a
chopped-up underline in the terminal (^^^^^---------^^^^^--------) and
as fragmented ranges in LSP.

This PR uses the self type span (impl_.self_ty.span) as the primary span
in emit_orphan_check_error, so the trait label and the primary span no
longer overlap. Only diagnostic output changes; there are no logic changes.

Before:

LL | impl Into<i32> for Box<i32> {}
   | ^^^^^---------^^^^^--------
   |      |             |
   |      |             `i32` is not defined in the current crate
   |      this is not defined in the current crate because this is a foreign trait

After:

LL | impl Into<i32> for Box<i32> {}
   |      ---------     ^^^^^^^^ `i32` is not defined in the current crate
   |      |
   |      this is not defined in the current crate because this is a foreign trait

When the primary span and the label point at the same type (for example
impl Copy for i32 {}), they now coincide and are rendered as a single
underline with the label attached.

Notes for reviewers:

• The existing .stderr files for E0117 under tests/ui/coherence/ (and a
  few others) are re-blessed. The diff there is only the changed spans.
• The auto trait errors (E0321 etc.) use a different code path and are not
  touched.
• Adds tests/ui/coherence/orphan-foreign-trait-box.rs as a regression test
  for the case from the issue.
• The label wording (i32 on Box<i32>) is unchanged and out of scope here.

[rustbot]

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[maxdexh]

The code change looks good to me, thanks for writing this!
I'm not sure why there are still tests failing. Did you run x test --bless ui?

[VibhuGupta-dev]

Thanks for the review!

You were right, I had missed re-blessing some UI tests outside tests/ui/coherence that also emit E0117. I've now re-blessed them with ./x test --bless:

• tests/ui/any/reject_manual_impl
• tests/ui/field_representing_types/incoherent-impl (both old and next revisions)
• tests/ui/pin-ergonomics/impl-unpin (tait revision)
• tests/ui/traits/const-traits/const-and-non-const-impl
• tests/ui/traits/trait-implementation-for-non-local-types-67535
• tests/ui/type/pattern_types/range_patterns_trait_impls2

The diff in these files is only the changed primary span (it now points at the self type instead of the whole impl header). There are no other changes.

I also ran ./x test tests/ui/coherence locally on this branch and all tests pass.

I amended and force-pushed, so the PR is still a single commit.
@maxdexh

[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)

To only update this specific test, also pass `--test-args dropck/drop-on-non-struct.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/dropck/drop-on-non-struct.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/dropck/drop-on-non-struct" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers" "--edition=2015"
stdout: none
--- stderr -------------------------------
error[E0425]: cannot find type `Nonexistent` in this scope
##[error]  --> /checkout/tests/ui/dropck/drop-on-non-struct.rs:9:15
   |
---
To only update this specific test, also pass `--test-args error-codes/E0117.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/error-codes/E0117.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/error-codes/E0117" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers" "--edition=2015"
stdout: none
--- stderr -------------------------------
error[E0117]: only traits defined in the current crate can be implemented for primitive types
##[error]  --> /checkout/tests/ui/error-codes/E0117.rs:1:15
   |
LL | impl Drop for u32 {} //~ ERROR E0117
   |               ^^^ `u32` is not defined in the current crate
   |
   = note: impl doesn't have any local type before any uncovered type parameters
   = note: for more information see https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules
   = note: define and implement a trait or new type instead

error[E0120]: the `Drop` trait may only be implemented for local structs, enums, and unions
##[error]  --> /checkout/tests/ui/error-codes/E0117.rs:1:15
   |
LL | impl Drop for u32 {} //~ ERROR E0117
   |               ^^^ must be a struct, enum, or union in the current crate

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0117, E0120.
For more information about an error, try `rustc --explain E0117`.
---
1 error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
-   --> $DIR/complex-impl.rs:9:1
+   --> $DIR/complex-impl.rs:9:22
3    |
4 LL | impl<R> External for (Q, R) {}
-    | ^^^^^^^^^^^^^^^^^^^^^------
-    |                      |
-    |                      this is not defined in the current crate because tuples are always foreign
+    |                      ^^^^^^ this is not defined in the current crate because tuples are always foreign
8    |
---
To only update this specific test, also pass `--test-args error-codes/e0119/complex-impl.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/error-codes/e0119/complex-impl.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/error-codes/e0119/complex-impl" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/error-codes/e0119/complex-impl/auxiliary" "--edition=2015"
stdout: none
--- stderr -------------------------------
error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
##[error]  --> /checkout/tests/ui/error-codes/e0119/complex-impl.rs:9:22
   |
LL | impl<R> External for (Q, R) {} //~ ERROR only traits defined
   |                      ^^^^^^ this is not defined in the current crate because tuples are always foreign
   |
   = note: impl doesn't have any local type before any uncovered type parameters
   = note: for more information see https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules
   = note: define and implement a trait or new type instead

---
19 error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
-   --> $DIR/issue-99572-impl-trait-on-pointer.rs:19:1
+   --> $DIR/issue-99572-impl-trait-on-pointer.rs:19:26
21    |
22 LL | impl<T> marker::Copy for *mut T {
-    | ^^^^^^^^^^^^^^^^^^^^^^^^^------
-    |                          |
-    |                          `*mut T` is not defined in the current crate because raw pointers are always foreign
+    |                          ^^^^^^ `*mut T` is not defined in the current crate because raw pointers are always foreign
26    |
---
To only update this specific test, also pass `--test-args errors/issue-99572-impl-trait-on-pointer.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/errors/issue-99572-impl-trait-on-pointer.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/errors/issue-99572-impl-trait-on-pointer" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers" "--edition=2015"
stdout: none
--- stderr -------------------------------
error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
##[error]  --> /checkout/tests/ui/errors/issue-99572-impl-trait-on-pointer.rs:7:23
   |
---

error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
##[error]  --> /checkout/tests/ui/errors/issue-99572-impl-trait-on-pointer.rs:19:26
   |
LL | impl<T> marker::Copy for *mut T {
   |                          ^^^^^^ `*mut T` is not defined in the current crate because raw pointers are always foreign
   |
   = note: impl doesn't have any local type before any uncovered type parameters
   = note: for more information see https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules
   = note: define and implement a trait or new type instead

---
1 error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
-   --> $DIR/unpin-for-future.rs:19:1
+   --> $DIR/unpin-for-future.rs:19:16
3    |
4 LL | impl Unpin for MyFut {}
-    | ^^^^^^^^^^^^^^^-----
-    |                |
-    |                `MyFut` is not defined in the current crate
+    |                ^^^^^ `MyFut` is not defined in the current crate
8    |
9    = note: impl doesn't have any local type before any uncovered type parameters
10    = note: for more information see https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules

Note: some mismatched output was normalized before being compared
-   --> /checkout/tests/ui/impl-trait/unpin-for-future.rs:19:16
+   --> $DIR/unpin-for-future.rs:19:16
+    |                ^^^^^ `MyFut` is not defined in the current crate


The actual stderr differed from the expected stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args impl-trait/unpin-for-future.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/impl-trait/unpin-for-future.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/impl-trait/unpin-for-future" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers" "--edition=2024"
stdout: none
--- stderr -------------------------------
error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
##[error]  --> /checkout/tests/ui/impl-trait/unpin-for-future.rs:19:16
   |
LL | impl Unpin for MyFut {}
   |                ^^^^^ `MyFut` is not defined in the current crate
   |
   = note: impl doesn't have any local type before any uncovered type parameters
   = note: for more information see https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules
   = note: define and implement a trait or new type instead

[oli-obk]

For the future, please avoid generating PR descriptions and comments with LLMs. Even if you write part of them yourself, there is no benefit to us to include the verbose things like which commands you ran and which tests you modified. All of that is visible to us in the diff, so this should be just information the LLM gives to you, but you should only write messages to us including things actually relevant to us.

That said: please read our LLM policy on how to contribute to this project in general.

[oli-obk]

I've now re-blessed them with ./x test --bless:

considering the new error that occurred in CI, did you actually run that command?