In error messages, don't assume attributes are always proc macros

joshtriplett · joshtriplett · commit 92dce4dd0020 · 2025-07-28T04:24:40.000-07:00
Now that `macro_rules` macros can define attribute rules, make sure
error messages account for that.
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
@@ -417,7 +417,7 @@ pub trait Emitter {
                 if !redundant_span || always_backtrace {
                     let msg: Cow<'static, _> = match trace.kind {
                         ExpnKind::Macro(MacroKind::Attr, _) => {
-                            "this procedural macro expansion".into()
+                            "this macro attribute expansion".into()
                         }
                         ExpnKind::Macro(MacroKind::Derive, _) => {
                             "this derive macro expansion".into()
diff --git a/src/tools/miri/tests/fail/alloc/alloc_error_handler_custom.stderr b/src/tools/miri/tests/fail/alloc/alloc_error_handler_custom.stderr
@@ -11,7 +11,7 @@ note: inside `_::__rg_oom`
   --> tests/fail/alloc/alloc_error_handler_custom.rs:LL:CC
    |
 LL | #[alloc_error_handler]
-   | ---------------------- in this procedural macro expansion
+   | ---------------------- in this macro attribute expansion
 LL | fn alloc_error_handler(layout: Layout) -> ! {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: inside `alloc::alloc::handle_alloc_error::rt_error` at RUSTLIB/alloc/src/alloc.rs:LL:CC
diff --git a/tests/ui/alloc-error/alloc-error-handler-bad-signature-1.stderr b/tests/ui/alloc-error/alloc-error-handler-bad-signature-1.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/alloc-error-handler-bad-signature-1.rs:10:1
    |
 LL |    #[alloc_error_handler]
-   |    ---------------------- in this procedural macro expansion
+   |    ---------------------- in this macro attribute expansion
 LL | // fn oom(
 LL | ||     info: &Layout,
 LL | || ) -> ()
@@ -23,7 +23,7 @@ error[E0308]: mismatched types
   --> $DIR/alloc-error-handler-bad-signature-1.rs:10:1
    |
 LL |    #[alloc_error_handler]
-   |    ---------------------- in this procedural macro expansion
+   |    ---------------------- in this macro attribute expansion
 LL | // fn oom(
 LL | ||     info: &Layout,
 LL | || ) -> ()
diff --git a/tests/ui/alloc-error/alloc-error-handler-bad-signature-2.stderr b/tests/ui/alloc-error/alloc-error-handler-bad-signature-2.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/alloc-error-handler-bad-signature-2.rs:10:1
    |
 LL |    #[alloc_error_handler]
-   |    ---------------------- in this procedural macro expansion
+   |    ---------------------- in this macro attribute expansion
 LL | // fn oom(
 LL | ||     info: Layout,
 LL | || ) {
@@ -31,7 +31,7 @@ error[E0308]: mismatched types
   --> $DIR/alloc-error-handler-bad-signature-2.rs:10:1
    |
 LL |    #[alloc_error_handler]
-   |    ---------------------- in this procedural macro expansion
+   |    ---------------------- in this macro attribute expansion
 LL | // fn oom(
 LL | ||     info: Layout,
 LL | || ) {
diff --git a/tests/ui/alloc-error/alloc-error-handler-bad-signature-3.stderr b/tests/ui/alloc-error/alloc-error-handler-bad-signature-3.stderr
@@ -2,7 +2,7 @@ error[E0061]: this function takes 0 arguments but 1 argument was supplied
   --> $DIR/alloc-error-handler-bad-signature-3.rs:10:1
    |
 LL |   #[alloc_error_handler]
-   |   ---------------------- in this procedural macro expansion
+   |   ---------------------- in this macro attribute expansion
 LL |   fn oom() -> ! {
    |  _-^^^^^^^^^^^^
 LL | |     loop {}
diff --git a/tests/ui/allocator/not-an-allocator.stderr b/tests/ui/allocator/not-an-allocator.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
   --> $DIR/not-an-allocator.rs:2:11
    |
 LL | #[global_allocator]
-   | ------------------- in this procedural macro expansion
+   | ------------------- in this macro attribute expansion
 LL | static A: usize = 0;
    |           ^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
    |
@@ -12,7 +12,7 @@ error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
   --> $DIR/not-an-allocator.rs:2:11
    |
 LL | #[global_allocator]
-   | ------------------- in this procedural macro expansion
+   | ------------------- in this macro attribute expansion
 LL | static A: usize = 0;
    |           ^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
    |
@@ -23,7 +23,7 @@ error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
   --> $DIR/not-an-allocator.rs:2:11
    |
 LL | #[global_allocator]
-   | ------------------- in this procedural macro expansion
+   | ------------------- in this macro attribute expansion
 LL | static A: usize = 0;
    |           ^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
    |
@@ -34,7 +34,7 @@ error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
   --> $DIR/not-an-allocator.rs:2:11
    |
 LL | #[global_allocator]
-   | ------------------- in this procedural macro expansion
+   | ------------------- in this macro attribute expansion
 LL | static A: usize = 0;
    |           ^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
    |
diff --git a/tests/ui/allocator/two-allocators.stderr b/tests/ui/allocator/two-allocators.stderr
@@ -4,7 +4,7 @@ error: cannot define multiple global allocators
 LL | static A: System = System;
    | -------------------------- previous global allocator defined here
 LL | #[global_allocator]
-   | ------------------- in this procedural macro expansion
+   | ------------------- in this macro attribute expansion
 LL | static B: System = System;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot define a new global allocator
 
diff --git a/tests/ui/custom_test_frameworks/mismatch.stderr b/tests/ui/custom_test_frameworks/mismatch.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `TestDescAndFn: Testable` is not satisfied
   --> $DIR/mismatch.rs:9:1
    |
 LL | #[test]
-   | ------- in this procedural macro expansion
+   | ------- in this macro attribute expansion
 LL | fn wrong_kind(){}
    | ^^^^^^^^^^^^^^^^^ the trait `Testable` is not implemented for `TestDescAndFn`
    |
diff --git a/tests/ui/macros/macro-rules-attr-error.rs b/tests/ui/macros/macro-rules-attr-error.rs
@@ -0,0 +1,13 @@
+#![feature(macro_attr)]
+
+macro_rules! local_attr {
+    attr() { $($body:tt)* } => {
+        compile_error!(concat!("local_attr: ", stringify!($($body)*)));
+    };
+    //~^^ ERROR: local_attr
+}
+
+fn main() {
+    #[local_attr]
+    struct S;
+}
diff --git a/tests/ui/macros/macro-rules-attr-error.stderr b/tests/ui/macros/macro-rules-attr-error.stderr
@@ -0,0 +1,13 @@
+error: local_attr: struct S;
+  --> $DIR/macro-rules-attr-error.rs:5:9
+   |
+LL |         compile_error!(concat!("local_attr: ", stringify!($($body)*)));
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL |     #[local_attr]
+   |     ------------- in this macro attribute expansion
+   |
+   = note: this error originates in the attribute macro `local_attr` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/proc-macro/span-from-proc-macro.stderr b/tests/ui/proc-macro/span-from-proc-macro.stderr
@@ -10,7 +10,7 @@ LL |             field: MissingType
   ::: $DIR/span-from-proc-macro.rs:8:1
    |
 LL | #[error_from_attribute]
-   | ----------------------- in this procedural macro expansion
+   | ----------------------- in this macro attribute expansion
 
 error[E0412]: cannot find type `OtherMissingType` in this scope
   --> $DIR/auxiliary/span-from-proc-macro.rs:42:21
diff --git a/tests/ui/rfcs/rfc-1937-termination-trait/termination-trait-test-wrong-type.stderr b/tests/ui/rfcs/rfc-1937-termination-trait/termination-trait-test-wrong-type.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `f32: Termination` is not satisfied
   --> $DIR/termination-trait-test-wrong-type.rs:6:31
    |
 LL | #[test]
-   | ------- in this procedural macro expansion
+   | ------- in this macro attribute expansion
 LL | fn can_parse_zero_as_f32() -> Result<f32, ParseFloatError> {
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Termination` is not implemented for `f32`
    |
diff --git a/tests/ui/test-attrs/issue-12997-2.stderr b/tests/ui/test-attrs/issue-12997-2.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/issue-12997-2.rs:8:1
    |
 LL | #[bench]
-   | -------- in this procedural macro expansion
+   | -------- in this macro attribute expansion
 LL | fn bar(x: isize) { }
    | ^^^^^^^^^^^^^^^^^^^^
    | |
diff --git a/tests/ui/test-attrs/test-function-signature.stderr b/tests/ui/test-attrs/test-function-signature.stderr
@@ -26,7 +26,7 @@ error[E0277]: the trait bound `i32: Termination` is not satisfied
   --> $DIR/test-function-signature.rs:9:13
    |
 LL | #[test]
-   | ------- in this procedural macro expansion
+   | ------- in this macro attribute expansion
 LL | fn bar() -> i32 {
    |             ^^^ the trait `Termination` is not implemented for `i32`
    |

Original file line number	Diff line number	Diff line change
`@@ -417,7 +417,7 @@ pub trait Emitter {`
`417`	`417`	`if !redundant_span \|\| always_backtrace {`
`418`	`418`	`let msg: Cow<'static, _> = match trace.kind {`
`419`	`419`	`ExpnKind::Macro(MacroKind::Attr, _) => {`
`420`		`- "this procedural macro expansion".into()`
	`420`	`+ "this macro attribute expansion".into()`
`421`	`421`	`}`
`422`	`422`	`ExpnKind::Macro(MacroKind::Derive, _) => {`
`423`	`423`	`"this derive macro expansion".into()`
Original file line number	Diff line number	Diff line change
@@ -11,7 +11,7 @@ note: inside `_::__rg_oom`
`11`	`11`	`--> tests/fail/alloc/alloc_error_handler_custom.rs:LL:CC`
`12`	`12`	`\|`
`13`	`13`	`LL \| #[alloc_error_handler]`
`14`		`- \| ---------------------- in this procedural macro expansion`
	`14`	`+ \| ---------------------- in this macro attribute expansion`
`15`	`15`	`LL \| fn alloc_error_handler(layout: Layout) -> ! {`
`16`	`16`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`17`	`17`	= note: inside `alloc::alloc::handle_alloc_error::rt_error` at RUSTLIB/alloc/src/alloc.rs:LL:CC
Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@ error[E0061]: this function takes 0 arguments but 1 argument was supplied`
`2`	`2`	`--> $DIR/alloc-error-handler-bad-signature-3.rs:10:1`
`3`	`3`	`\|`
`4`	`4`	`LL \| #[alloc_error_handler]`
`5`		`- \| ---------------------- in this procedural macro expansion`
	`5`	`+ \| ---------------------- in this macro attribute expansion`
`6`	`6`	`LL \| fn oom() -> ! {`
`7`	`7`	`\| _-^^^^^^^^^^^^`
`8`	`8`	`LL \| \| loop {}`
Original file line number	Diff line number	Diff line change
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
`2`	`2`	`--> $DIR/not-an-allocator.rs:2:11`
`3`	`3`	`\|`
`4`	`4`	`LL \| #[global_allocator]`
`5`		`- \| ------------------- in this procedural macro expansion`
	`5`	`+ \| ------------------- in this macro attribute expansion`
`6`	`6`	`LL \| static A: usize = 0;`
`7`	`7`	\| ^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
`8`	`8`	`\|`
@@ -12,7 +12,7 @@ error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
`12`	`12`	`--> $DIR/not-an-allocator.rs:2:11`
`13`	`13`	`\|`
`14`	`14`	`LL \| #[global_allocator]`
`15`		`- \| ------------------- in this procedural macro expansion`
	`15`	`+ \| ------------------- in this macro attribute expansion`
`16`	`16`	`LL \| static A: usize = 0;`
`17`	`17`	\| ^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
`18`	`18`	`\|`
@@ -23,7 +23,7 @@ error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
`23`	`23`	`--> $DIR/not-an-allocator.rs:2:11`
`24`	`24`	`\|`
`25`	`25`	`LL \| #[global_allocator]`
`26`		`- \| ------------------- in this procedural macro expansion`
	`26`	`+ \| ------------------- in this macro attribute expansion`
`27`	`27`	`LL \| static A: usize = 0;`
`28`	`28`	\| ^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
`29`	`29`	`\|`
@@ -34,7 +34,7 @@ error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
`34`	`34`	`--> $DIR/not-an-allocator.rs:2:11`
`35`	`35`	`\|`
`36`	`36`	`LL \| #[global_allocator]`
`37`		`- \| ------------------- in this procedural macro expansion`
	`37`	`+ \| ------------------- in this macro attribute expansion`
`38`	`38`	`LL \| static A: usize = 0;`
`39`	`39`	\| ^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
`40`	`40`	`\|`
Original file line number	Diff line number	Diff line change
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `TestDescAndFn: Testable` is not satisfied
`2`	`2`	`--> $DIR/mismatch.rs:9:1`
`3`	`3`	`\|`
`4`	`4`	`LL \| #[test]`
`5`		`- \| ------- in this procedural macro expansion`
	`5`	`+ \| ------- in this macro attribute expansion`
`6`	`6`	`LL \| fn wrong_kind(){}`
`7`	`7`	\| ^^^^^^^^^^^^^^^^^ the trait `Testable` is not implemented for `TestDescAndFn`
`8`	`8`	`\|`