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.

Author: Aaron1011

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