Align multiline messages to their label (add left margin)

compiler/rustc_errors/src/emitter.rs

@@ -1266,22 +1266,37 @@ impl EmitterWriter {
             }
             self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
         } else {
+            let mut label_width = 0;
             // The failure note level itself does not provide any useful diagnostic information
             if *level != Level::FailureNote {
                 buffer.append(0, level.to_str(), Style::Level(*level));
+                label_width += level.to_str().len();
             }
             // only render error codes, not lint codes
             if let Some(DiagnosticId::Error(ref code)) = *code {
                 buffer.append(0, "[", Style::Level(*level));
                 buffer.append(0, &code, Style::Level(*level));
                 buffer.append(0, "]", Style::Level(*level));
+                label_width += 2 + code.len();
             }
             let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
             if *level != Level::FailureNote {
                 buffer.append(0, ": ", header_style);
+                label_width += 2;
             }
             for &(ref text, _) in msg.iter() {
-                buffer.append(0, &replace_tabs(text), header_style);
+                // Account for newlines to align output to its label.
+                for (line, text) in replace_tabs(text).lines().enumerate() {
+                    buffer.append(
+                        0 + line,
+                        &format!(
+                            "{}{}",
+                            if line == 0 { String::new() } else { " ".repeat(label_width) },
+                            text
+                        ),
+                        header_style,
+                    );
+                }
             }
         }
 

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

@@ -24,7 +24,7 @@ error: unexpected token: `{
                                                                                                       ::core::fmt::Display::fmt)],
                                                                     }));
            res
-}.as_str()`
+       }.as_str()`
   --> $DIR/key-value-expansion.rs:48:23
    |
 LL |         doc_comment! {format!("{coor}", coor = stringify!($t1)).as_str()}

src/test/ui/cmse-nonsecure/cmse-nonsecure-call/params-on-stack.stderr

@@ -1,5 +1,4 @@
 error: <unknown>:0:0: in function test i32 (i32, i32, i32, i32, i32): call to non-secure function would require passing arguments on stack
 
-
 error: aborting due to previous error
 

src/test/ui/cmse-nonsecure/cmse-nonsecure-entry/params-on-stack.stderr

@@ -1,5 +1,4 @@
 error: <unknown>:0:0: in function entry_function i32 (i32, i32, i32, i32, i32): secure entry function requires arguments on stack
 
-
 error: aborting due to previous error
 

src/test/ui/layout/debug.stderr

@@ -104,7 +104,7 @@ error: layout_of(E) = Layout {
            size: Size {
                raw: 12,
            },
-}
+       }
   --> $DIR/debug.rs:6:1
    |
 LL | enum E { Foo, Bar(!, i32, i32) }
@@ -158,7 +158,7 @@ error: layout_of(S) = Layout {
            size: Size {
                raw: 8,
            },
-}
+       }
   --> $DIR/debug.rs:9:1
    |
 LL | struct S { f1: i32, f2: (), f3: i32 }
@@ -184,7 +184,7 @@ error: layout_of(U) = Layout {
            size: Size {
                raw: 8,
            },
-}
+       }
   --> $DIR/debug.rs:12:1
    |
 LL | union U { f1: (i32, i32), f3: i32 }
@@ -309,7 +309,7 @@ error: layout_of(std::result::Result<i32, i32>) = Layout {
            size: Size {
                raw: 8,
            },
-}
+       }
   --> $DIR/debug.rs:15:1
    |
 LL | type Test = Result<i32, i32>;
@@ -339,7 +339,7 @@ error: layout_of(i32) = Layout {
            size: Size {
                raw: 4,
            },
-}
+       }
   --> $DIR/debug.rs:18:1
    |
 LL | type T = impl std::fmt::Debug;

src/test/ui/layout/hexagon-enum.stderr

@@ -80,7 +80,7 @@ error: layout_of(A) = Layout {
            size: Size {
                raw: 1,
            },
-}
+       }
   --> $DIR/hexagon-enum.rs:16:1
    |
 LL | enum A { Apple }
@@ -168,7 +168,7 @@ error: layout_of(B) = Layout {
            size: Size {
                raw: 1,
            },
-}
+       }
   --> $DIR/hexagon-enum.rs:20:1
    |
 LL | enum B { Banana = 255, }
@@ -256,7 +256,7 @@ error: layout_of(C) = Layout {
            size: Size {
                raw: 2,
            },
-}
+       }
   --> $DIR/hexagon-enum.rs:24:1
    |
 LL | enum C { Chaenomeles = 256, }
@@ -344,7 +344,7 @@ error: layout_of(P) = Layout {
            size: Size {
                raw: 4,
            },
-}
+       }
   --> $DIR/hexagon-enum.rs:28:1
    |
 LL | enum P { Peach = 0x1000_0000isize, }
@@ -432,7 +432,7 @@ error: layout_of(T) = Layout {
            size: Size {
                raw: 4,
            },
-}
+       }
   --> $DIR/hexagon-enum.rs:34:1
    |
 LL | enum T { Tangerine = TANGERINE as isize }

src/test/ui/layout/thumb-enum.stderr

@@ -80,7 +80,7 @@ error: layout_of(A) = Layout {
            size: Size {
                raw: 1,
            },
-}
+       }
   --> $DIR/thumb-enum.rs:16:1
    |
 LL | enum A { Apple }
@@ -168,7 +168,7 @@ error: layout_of(B) = Layout {
            size: Size {
                raw: 1,
            },
-}
+       }
   --> $DIR/thumb-enum.rs:20:1
    |
 LL | enum B { Banana = 255, }
@@ -256,7 +256,7 @@ error: layout_of(C) = Layout {
            size: Size {
                raw: 2,
            },
-}
+       }
   --> $DIR/thumb-enum.rs:24:1
    |
 LL | enum C { Chaenomeles = 256, }
@@ -344,7 +344,7 @@ error: layout_of(P) = Layout {
            size: Size {
                raw: 4,
            },
-}
+       }
   --> $DIR/thumb-enum.rs:28:1
    |
 LL | enum P { Peach = 0x1000_0000isize, }
@@ -432,7 +432,7 @@ error: layout_of(T) = Layout {
            size: Size {
                raw: 4,
            },
-}
+       }
   --> $DIR/thumb-enum.rs:34:1
    |
 LL | enum T { Tangerine = TANGERINE as isize }

src/test/ui/traits/vtable/vtable-diamond.stderr

@@ -7,7 +7,7 @@ error: vtable entries for `<S as D>`: [
            Method(<S as C>::foo_c),
            TraitVPtr(<S as C>),
            Method(<S as D>::foo_d),
-]
+       ]
   --> $DIR/vtable-diamond.rs:21:1
    |
 LL | / trait D: B + C {
@@ -22,7 +22,7 @@ error: vtable entries for `<S as C>`: [
            MetadataAlign,
            Method(<S as A>::foo_a),
            Method(<S as C>::foo_c),
-]
+       ]
   --> $DIR/vtable-diamond.rs:15:1
    |
 LL | / trait C: A {

src/test/ui/traits/vtable/vtable-multi-level.stderr

@@ -28,7 +28,7 @@ error: vtable entries for `<S as O>`: [
            Method(<S as N>::foo_n),
            TraitVPtr(<S as N>),
            Method(<S as O>::foo_o),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:95:1
    |
 LL | / trait O: G + N {
@@ -42,7 +42,7 @@ error: vtable entries for `<S as B>`: [
            MetadataSize,
            MetadataAlign,
            Method(<S as B>::foo_b),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:19:1
    |
 LL | / trait B {
@@ -56,7 +56,7 @@ error: vtable entries for `<S as D>`: [
            MetadataSize,
            MetadataAlign,
            Method(<S as D>::foo_d),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:30:1
    |
 LL | / trait D {
@@ -70,7 +70,7 @@ error: vtable entries for `<S as E>`: [
            MetadataSize,
            MetadataAlign,
            Method(<S as E>::foo_e),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:36:1
    |
 LL | / trait E {
@@ -87,7 +87,7 @@ error: vtable entries for `<S as F>`: [
            Method(<S as E>::foo_e),
            TraitVPtr(<S as E>),
            Method(<S as F>::foo_f),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:42:1
    |
 LL | / trait F: D + E {
@@ -101,7 +101,7 @@ error: vtable entries for `<S as H>`: [
            MetadataSize,
            MetadataAlign,
            Method(<S as H>::foo_h),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:53:1
    |
 LL | / trait H {
@@ -115,7 +115,7 @@ error: vtable entries for `<S as I>`: [
            MetadataSize,
            MetadataAlign,
            Method(<S as I>::foo_i),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:59:1
    |
 LL | / trait I {
@@ -132,7 +132,7 @@ error: vtable entries for `<S as J>`: [
            Method(<S as I>::foo_i),
            TraitVPtr(<S as I>),
            Method(<S as J>::foo_j),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:65:1
    |
 LL | / trait J: H + I {
@@ -146,7 +146,7 @@ error: vtable entries for `<S as K>`: [
            MetadataSize,
            MetadataAlign,
            Method(<S as K>::foo_k),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:71:1
    |
 LL | / trait K {
@@ -160,7 +160,7 @@ error: vtable entries for `<S as L>`: [
            MetadataSize,
            MetadataAlign,
            Method(<S as L>::foo_l),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:77:1
    |
 LL | / trait L {
@@ -177,7 +177,7 @@ error: vtable entries for `<S as M>`: [
            Method(<S as L>::foo_l),
            TraitVPtr(<S as L>),
            Method(<S as M>::foo_m),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:83:1
    |
 LL | / trait M: K + L {
@@ -201,7 +201,7 @@ error: vtable entries for `<S as N>`: [
            Method(<S as M>::foo_m),
            TraitVPtr(<S as M>),
            Method(<S as N>::foo_n),
-]
+       ]
   --> $DIR/vtable-multi-level.rs:89:1
    |
 LL | / trait N: J + M {

src/test/ui/traits/vtable/vtable-multiple.stderr

@@ -6,7 +6,7 @@ error: vtable entries for `<S as C>`: [
            Method(<S as B>::foo_b),
            TraitVPtr(<S as B>),
            Method(<S as C>::foo_c),
-]
+       ]
   --> $DIR/vtable-multiple.rs:16:1
    |
 LL | / trait C: A + B {
@@ -20,7 +20,7 @@ error: vtable entries for `<S as B>`: [
            MetadataSize,
            MetadataAlign,
            Method(<S as B>::foo_b),
-]
+       ]
   --> $DIR/vtable-multiple.rs:10:1
    |
 LL | / trait B {

src/test/ui/traits/vtable/vtable-non-object-safe.stderr

@@ -6,7 +6,7 @@ error: vtable entries for `<std::vec::IntoIter<u8> as A>`: [
            Method(<std::vec::IntoIter<u8> as Iterator>::size_hint),
            Method(<std::vec::IntoIter<u8> as Iterator>::advance_by),
            Method(<std::vec::IntoIter<u8> as Iterator>::nth),
-]
+       ]
   --> $DIR/vtable-non-object-safe.rs:8:1
    |
 LL | trait A: Iterator {}

src/test/ui/traits/vtable/vtable-vacant.stderr

@@ -6,7 +6,7 @@ error: vtable entries for `<S as B>`: [
            Vacant,
            Method(<S as B>::foo_b1),
            Vacant,
-]
+       ]
   --> $DIR/vtable-vacant.rs:15:1
    |
 LL | / trait B: A {