Show macro name in 'this error originates in macro' message

When there are multiple macros in use, it can be difficult to tell
which one was responsible for producing an error.

compiler/rustc_errors/src/emitter.rs

@@ -309,8 +309,8 @@ pub trait Emitter {
                     // are some which do actually involve macros.
                     ExpnKind::Inlined | ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None,
 
-                    ExpnKind::Macro { kind: macro_kind, name: _, proc_macro: _ } => {
-                        Some(macro_kind)
+                    ExpnKind::Macro { kind: macro_kind, name, proc_macro: _ } => {
+                        Some((macro_kind, name))
                     }
                 }
             });
@@ -322,13 +322,12 @@ pub trait Emitter {
         self.render_multispans_macro_backtrace(span, children, backtrace);
 
         if !backtrace {
-            if let Some(macro_kind) = has_macro_spans {
+            if let Some((macro_kind, name)) = has_macro_spans {
+                let descr = macro_kind.descr();
+
                 let msg = format!(
-                    "this {} originates in {} {} \
+                    "this {level} originates in the {descr} `{name}` \
                     (in Nightly builds, run with -Z macro-backtrace for more info)",
-                    level,
-                    macro_kind.article(),
-                    macro_kind.descr(),
                 );
 
                 children.push(SubDiagnostic {

compiler/rustc_errors/src/lib.rs

@@ -6,6 +6,7 @@
 #![feature(crate_visibility_modifier)]
 #![feature(backtrace)]
 #![feature(extended_key_value_attributes)]
+#![feature(format_args_capture)]
 #![feature(iter_zip)]
 #![feature(nll)]
 

src/test/rustdoc-ui/intra-doc/warning.stderr

@@ -96,7 +96,7 @@ LL | f!("Foo\nbar [BarF] bar\nbaz");
                 ^^^^
    = note: no item named `BarF` in scope
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
-   = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this warning originates in the macro `f` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 warning: unresolved link to `error`
   --> $DIR/warning.rs:58:30

src/test/ui-fulldeps/hash-stable-is-unstable.stderr

@@ -42,7 +42,7 @@ LL | #[derive(HashStable)]
    |
    = note: see issue #27812 <https://github.com/rust-lang/rust/issues/27812> for more information
    = help: add `#![feature(rustc_private)]` to the crate attributes to enable
-   = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `HashStable` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 5 previous errors
 

src/test/ui-fulldeps/internal-lints/lint_pass_impl_without_macro.stderr

@@ -21,7 +21,7 @@ LL | custom_lint_pass_macro!();
    | -------------------------- in this macro invocation
    |
    = help: try using `declare_lint_pass!` or `impl_lint_pass!` instead
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `custom_lint_pass_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 2 previous errors
 

src/test/ui-fulldeps/session-derive-errors.stderr

@@ -62,7 +62,7 @@ LL | #[message = "This is missing a closing brace: {name"]
    | ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
-   = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `SessionDiagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: invalid format string: unmatched `}` found
   --> $DIR/session-derive-errors.rs:119:1
@@ -71,7 +71,7 @@ LL | #[message = "This is missing an opening brace: name}"]
    | ^ unmatched `}` in format string
    |
    = note: if you intended to print `}`, you can escape it using `}}`
-   = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `SessionDiagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: The `#[label = ...]` attribute can only be applied to fields of type Span
   --> $DIR/session-derive-errors.rs:138:5

src/test/ui/allocator/not-an-allocator.stderr

@@ -5,7 +5,7 @@ LL | static A: usize = 0;
    | ^^^^^^^^^^^^^^^^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
    |
    = note: required by `std::alloc::GlobalAlloc::alloc`
-   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the attribute macro `global_allocator` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
   --> $DIR/not-an-allocator.rs:2:1
@@ -14,7 +14,7 @@ LL | static A: usize = 0;
    | ^^^^^^^^^^^^^^^^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
    |
    = note: required by `std::alloc::GlobalAlloc::dealloc`
-   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the attribute macro `global_allocator` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
   --> $DIR/not-an-allocator.rs:2:1
@@ -23,7 +23,7 @@ LL | static A: usize = 0;
    | ^^^^^^^^^^^^^^^^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
    |
    = note: required by `std::alloc::GlobalAlloc::realloc`
-   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the attribute macro `global_allocator` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
   --> $DIR/not-an-allocator.rs:2:1
@@ -32,7 +32,7 @@ LL | static A: usize = 0;
    | ^^^^^^^^^^^^^^^^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
    |
    = note: required by `std::alloc::GlobalAlloc::alloc_zeroed`
-   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the attribute macro `global_allocator` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 4 previous errors
 

src/test/ui/allocator/two-allocators.stderr

@@ -7,7 +7,7 @@ LL | #[global_allocator]
 LL | static B: System = System;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot define a new global allocator
    |
-   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the attribute macro `global_allocator` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error
 

src/test/ui/asm/interpolated-idents.stderr

@@ -9,7 +9,7 @@ LL | |        pure nomem readonly preserves_flags
 LL | |        noreturn nostack att_syntax options);
    | |____________________________________________- in this macro invocation
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: the `pure` and `noreturn` options are mutually exclusive
   --> $DIR/interpolated-idents.rs:13:13
@@ -22,7 +22,7 @@ LL | |        pure nomem readonly preserves_flags
 LL | |        noreturn nostack att_syntax options);
    | |____________________________________________- in this macro invocation
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: asm outputs are not allowed with the `noreturn` option
   --> $DIR/interpolated-idents.rs:10:32
@@ -45,7 +45,7 @@ LL | |        noreturn nostack att_syntax options);
    | |____________________________________________in this macro invocation
    |                                              in this macro invocation
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 3 previous errors
 

src/test/ui/asm/naked-functions.stderr

@@ -233,7 +233,7 @@ LL |     llvm_asm!("");
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #32408 <https://github.com/rust-lang/rust/issues/32408>
    = help: use the new asm! syntax specified in RFC 2873
-   = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this warning originates in the macro `llvm_asm` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 warning: naked functions must contain a single asm block
   --> $DIR/naked-functions.rs:108:1

src/test/ui/asm/parse-error.stderr

@@ -154,15 +154,15 @@ error: asm template must be a string literal
 LL |         asm!(format!("{{{}}}", 0), in(reg) foo);
    |              ^^^^^^^^^^^^^^^^^^^^
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `format` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: asm template must be a string literal
   --> $DIR/parse-error.rs:62:21
    |
 LL |         asm!("{1}", format!("{{{}}}", 0), in(reg) foo, out(reg) bar);
    |                     ^^^^^^^^^^^^^^^^^^^^
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `format` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0435]: attempt to use a non-constant value in a constant
   --> $DIR/parse-error.rs:37:37

src/test/ui/asm/type-check-2.stderr

@@ -27,7 +27,7 @@ LL |         asm!("{}", in(reg) vec![0]);
    |                            ^^^^^^^
    |
    = note: only integers, floats, SIMD vectors, pointers and function pointers can be used as arguments for inline assembly
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: cannot use value of type `(i32, i32, i32)` for inline assembly
   --> $DIR/type-check-2.rs:70:28

src/test/ui/associated-consts/defaults-not-assumed-fail.stderr

@@ -24,7 +24,7 @@ LL |     assert_eq!(<() as Tr>::B, 0);    // causes the error above
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800>
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 3 previous errors
 

src/test/ui/async-await/issue-73541-2.stderr

@@ -11,7 +11,7 @@ LL |                 b!();
    |                 ----- in this macro invocation
    |
    = note: labels are unreachable through functions, closures, async blocks and modules
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `b` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error
 

src/test/ui/attributes/key-value-expansion.stderr

@@ -13,7 +13,7 @@ LL |         bug!("bug" + stringify!(found));
 LL | bug!();
    | ------- in this macro invocation
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `bug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: unexpected token: `{
     let res =
@@ -33,7 +33,7 @@ LL |         doc_comment! {format!("{coor}", coor = stringify!($t1)).as_str()}
 LL | some_macro!(u8);
    | ---------------- in this macro invocation
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `some_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 3 previous errors
 

src/test/ui/attributes/nonterminal-expansion.stderr

@@ -7,7 +7,7 @@ LL |         #[repr(align($n))]
 LL | pass_nonterminal!(n!());
    | ------------------------ in this macro invocation
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `pass_nonterminal` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error
 

src/test/ui/binop/issue-77910-1.stderr

@@ -7,7 +7,7 @@ LL |     assert_eq!(foo, y);
    |     for<'r> fn(&'r i32) -> &'r i32 {foo}
    |     _
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: `for<'r> fn(&'r i32) -> &'r i32 {foo}` doesn't implement `Debug`
   --> $DIR/issue-77910-1.rs:8:5
@@ -21,7 +21,7 @@ LL |     T: fmt::Debug + ?Sized,
    |        ---------- required by this bound in `core::panicking::assert_failed`
    |
    = help: the trait `Debug` is not implemented for `for<'r> fn(&'r i32) -> &'r i32 {foo}`
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 2 previous errors
 

src/test/ui/borrowck/borrowck-borrowed-uniq-rvalue-2.stderr

@@ -9,7 +9,7 @@ LL |     x.x[0];
    |     ------ borrow later used here
    |
    = note: consider using a `let` binding to create a longer lived value
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error
 

src/test/ui/borrowck/issue-25793.stderr

@@ -11,7 +11,7 @@ LL |         r.get_size(width!(self))
    |           |
    |           borrow later used by call
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `width` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error
 

src/test/ui/borrowck/issue-64453.stderr

@@ -10,15 +10,15 @@ error[E0015]: calls in statics are limited to constant functions, tuple structs
 LL | static settings_dir: String = format!("");
    |                               ^^^^^^^^^^^
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::__export::format_args` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
   --> $DIR/issue-64453.rs:4:31
    |
 LL | static settings_dir: String = format!("");
    |                               ^^^^^^^^^^^
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `format` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 3 previous errors
 

src/test/ui/borrowck/move-error-snippets.stderr

@@ -12,7 +12,7 @@ LL |         let a = $c;
 LL | sss!();
    | ------- in this macro invocation
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `aaa` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error
 

src/test/ui/bound-suggestions.stderr

@@ -5,7 +5,7 @@ LL |     println!("{:?}", t);
    |                      ^ `impl Sized` cannot be formatted using `{:?}` because it doesn't implement `Debug`
    |
    = note: required by `std::fmt::Debug::fmt`
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::format_args_nl` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting this bound
    |
 LL | fn test_impl(t: impl Sized + std::fmt::Debug) {
@@ -18,7 +18,7 @@ LL |     println!("{:?}", t);
    |                      ^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug`
    |
    = note: required by `std::fmt::Debug::fmt`
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::format_args_nl` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider restricting type parameter `T`
    |
 LL | fn test_no_bounds<T: std::fmt::Debug>(t: T) {
@@ -31,7 +31,7 @@ LL |     println!("{:?}", t);
    |                      ^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug`
    |
    = note: required by `std::fmt::Debug::fmt`
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::format_args_nl` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting this bound
    |
 LL | fn test_one_bound<T: Sized + std::fmt::Debug>(t: T) {
@@ -44,7 +44,7 @@ LL |     println!("{:?} {:?}", x, y);
    |                              ^ `Y` cannot be formatted using `{:?}` because it doesn't implement `Debug`
    |
    = note: required by `std::fmt::Debug::fmt`
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::format_args_nl` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting type parameter `Y`
    |
 LL | fn test_no_bounds_where<X, Y>(x: X, y: Y) where X: std::fmt::Debug, Y: std::fmt::Debug {
@@ -57,7 +57,7 @@ LL |     println!("{:?}", x);
    |                      ^ `X` cannot be formatted using `{:?}` because it doesn't implement `Debug`
    |
    = note: required by `std::fmt::Debug::fmt`
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::format_args_nl` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting this bound
    |
 LL | fn test_one_bound_where<X>(x: X) where X: Sized + std::fmt::Debug {
@@ -70,7 +70,7 @@ LL |     println!("{:?}", x);
    |                      ^ `X` cannot be formatted using `{:?}` because it doesn't implement `Debug`
    |
    = note: required by `std::fmt::Debug::fmt`
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::format_args_nl` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider further restricting type parameter `X`
    |
 LL | fn test_many_bounds_where<X>(x: X) where X: Sized, X: Sized, X: std::fmt::Debug {

src/test/ui/codemap_tests/bad-format-args.stderr

@@ -4,7 +4,7 @@ error: requires at least a format string argument
 LL |     format!();
    |     ^^^^^^^^^^
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `$crate::__export::format_args` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: expected `,`, found `1`
   --> $DIR/bad-format-args.rs:3:16

src/test/ui/codemap_tests/issue-28308.stderr

@@ -4,7 +4,7 @@ error[E0600]: cannot apply unary operator `!` to type `&'static str`
 LL |     assert!("foo");
    |     ^^^^^^^^^^^^^^^ cannot apply unary operator `!`
    |
-   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error