Use ident.span instead of def_span in dead-code pass

src/librustc_passes/dead.rs

@@ -569,16 +569,26 @@ impl Visitor<'tcx> for DeadVisitor<'tcx> {
 
     fn visit_item(&mut self, item: &'tcx hir::Item) {
         if self.should_warn_about_item(item) {
-            // For items that have a definition with a signature followed by a
-            // block, point only at the signature.
+            // For most items, we want to highlight its identifier
             let span = match item.kind {
                 hir::ItemKind::Fn(..) |
                 hir::ItemKind::Mod(..) |
                 hir::ItemKind::Enum(..) |
                 hir::ItemKind::Struct(..) |
                 hir::ItemKind::Union(..) |
                 hir::ItemKind::Trait(..) |
-                hir::ItemKind::Impl(..) => self.tcx.sess.source_map().def_span(item.span),
+                hir::ItemKind::Impl(..) => {
+                    // FIXME(66095): Because item.span is annotated with things
+                    // like a macro_backtrace, and ident.span isn't, we use the
+                    // def_span method if it's part of a macro invocation
+                    // We should probably annotate ident.span with the macro
+                    // context, but that's a larger change.
+                    if item.span.macro_backtrace().len() == 0 {
+                        item.ident.span
+                    } else {
+                        self.tcx.sess.source_map().def_span(item.span)
+                    }
+                },
                 _ => item.span,
             };
             let participle = match item.kind {

src/test/ui-fulldeps/lint-plugin-cmdline-allow.stderr

@@ -7,10 +7,10 @@ LL | #![plugin(lint_plugin_test)]
    = note: `#[warn(deprecated)]` on by default
 
 warning: function is never used: `lintme`
-  --> $DIR/lint-plugin-cmdline-allow.rs:10:1
+  --> $DIR/lint-plugin-cmdline-allow.rs:10:4
    |
 LL | fn lintme() { }
-   | ^^^^^^^^^^^
+   |    ^^^^^^
    |
 note: lint level defined here
   --> $DIR/lint-plugin-cmdline-allow.rs:7:9

src/test/ui-fulldeps/lint-tool-cmdline-allow.stderr

@@ -19,10 +19,10 @@ LL | fn lintme() {}
    = note: `#[warn(clippy::test_lint)]` on by default
 
 warning: function is never used: `lintme`
-  --> $DIR/lint-tool-cmdline-allow.rs:10:1
+  --> $DIR/lint-tool-cmdline-allow.rs:10:4
    |
 LL | fn lintme() {}
-   | ^^^^^^^^^^^
+   |    ^^^^^^
    |
 note: lint level defined here
   --> $DIR/lint-tool-cmdline-allow.rs:7:9

src/test/ui/fail-no-dead-code.stderr → src/test/ui/lint/dead-code/basic.stderr

@@ -1,11 +1,11 @@
 error: function is never used: `foo`
-  --> $DIR/fail-no-dead-code.rs:4:1
+  --> $DIR/basic.rs:4:4
    |
 LL | fn foo() {
-   | ^^^^^^^^
+   |    ^^^
    |
 note: lint level defined here
-  --> $DIR/fail-no-dead-code.rs:1:9
+  --> $DIR/basic.rs:1:9
    |
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^

src/test/ui/lint/lint-dead-code-empty-unused-enum.stderr → src/test/ui/lint/dead-code/empty-unused-enum.stderr

@@ -1,11 +1,11 @@
 error: enum is never used: `E`
-  --> $DIR/lint-dead-code-empty-unused-enum.rs:3:1
+  --> $DIR/empty-unused-enum.rs:3:6
    |
 LL | enum E {}
-   | ^^^^^^
+   |      ^
    |
 note: lint level defined here
-  --> $DIR/lint-dead-code-empty-unused-enum.rs:1:9
+  --> $DIR/empty-unused-enum.rs:1:9
    |
 LL | #![deny(unused)]
    |         ^^^^^^

src/test/ui/lint/lint-dead-code-impl-trait.stderr → src/test/ui/lint/dead-code/impl-trait.stderr

@@ -1,11 +1,11 @@
 error: type alias is never used: `Unused`
-  --> $DIR/lint-dead-code-impl-trait.rs:12:1
+  --> $DIR/impl-trait.rs:12:1
    |
 LL | type Unused = ();
    | ^^^^^^^^^^^^^^^^^
    |
 note: lint level defined here
-  --> $DIR/lint-dead-code-impl-trait.rs:1:9
+  --> $DIR/impl-trait.rs:1:9
    |
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^

src/test/ui/lint/lint-dead-code-1.stderr → src/test/ui/lint/dead-code/lint-dead-code-1.stderr

@@ -1,8 +1,8 @@
 error: struct is never constructed: `Bar`
-  --> $DIR/lint-dead-code-1.rs:12:5
+  --> $DIR/lint-dead-code-1.rs:12:16
    |
 LL |     pub struct Bar;
-   |     ^^^^^^^^^^^^^^^
+   |                ^^^
    |
 note: lint level defined here
   --> $DIR/lint-dead-code-1.rs:5:9
@@ -23,16 +23,16 @@ LL | const priv_const: isize = 0;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: struct is never constructed: `PrivStruct`
-  --> $DIR/lint-dead-code-1.rs:35:1
+  --> $DIR/lint-dead-code-1.rs:35:8
    |
 LL | struct PrivStruct;
-   | ^^^^^^^^^^^^^^^^^^
+   |        ^^^^^^^^^^
 
 error: enum is never used: `priv_enum`
-  --> $DIR/lint-dead-code-1.rs:64:1
+  --> $DIR/lint-dead-code-1.rs:64:6
    |
 LL | enum priv_enum { foo2, bar2 }
-   | ^^^^^^^^^^^^^^
+   |      ^^^^^^^^^
 
 error: variant is never constructed: `bar3`
   --> $DIR/lint-dead-code-1.rs:67:5
@@ -41,28 +41,28 @@ LL |     bar3
    |     ^^^^
 
 error: function is never used: `priv_fn`
-  --> $DIR/lint-dead-code-1.rs:88:1
+  --> $DIR/lint-dead-code-1.rs:88:4
    |
 LL | fn priv_fn() {
-   | ^^^^^^^^^^^^
+   |    ^^^^^^^
 
 error: function is never used: `foo`
-  --> $DIR/lint-dead-code-1.rs:93:1
+  --> $DIR/lint-dead-code-1.rs:93:4
    |
 LL | fn foo() {
-   | ^^^^^^^^
+   |    ^^^
 
 error: function is never used: `bar`
-  --> $DIR/lint-dead-code-1.rs:98:1
+  --> $DIR/lint-dead-code-1.rs:98:4
    |
 LL | fn bar() {
-   | ^^^^^^^^
+   |    ^^^
 
 error: function is never used: `baz`
-  --> $DIR/lint-dead-code-1.rs:102:1
+  --> $DIR/lint-dead-code-1.rs:102:4
    |
 LL | fn baz() -> impl Copy {
-   | ^^^^^^^^^^^^^^^^^^^^^
+   |    ^^^
 
 error: aborting due to 10 previous errors
 

src/test/ui/lint/lint-dead-code-2.stderr → src/test/ui/lint/dead-code/lint-dead-code-2.stderr

@@ -1,8 +1,8 @@
 error: function is never used: `dead_fn`
-  --> $DIR/lint-dead-code-2.rs:22:1
+  --> $DIR/lint-dead-code-2.rs:22:4
    |
 LL | fn dead_fn() {}
-   | ^^^^^^^^^^^^
+   |    ^^^^^^^
    |
 note: lint level defined here
   --> $DIR/lint-dead-code-2.rs:2:9
@@ -11,16 +11,16 @@ LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
 error: function is never used: `dead_fn2`
-  --> $DIR/lint-dead-code-2.rs:25:1
+  --> $DIR/lint-dead-code-2.rs:25:4
    |
 LL | fn dead_fn2() {}
-   | ^^^^^^^^^^^^^
+   |    ^^^^^^^^
 
 error: function is never used: `main`
-  --> $DIR/lint-dead-code-2.rs:38:1
+  --> $DIR/lint-dead-code-2.rs:38:4
    |
 LL | fn main() {
-   | ^^^^^^^^^
+   |    ^^^^
 
 error: aborting due to 3 previous errors
 

src/test/ui/lint/lint-dead-code-3.stderr → src/test/ui/lint/dead-code/lint-dead-code-3.stderr

@@ -1,8 +1,8 @@
 error: struct is never constructed: `Foo`
-  --> $DIR/lint-dead-code-3.rs:13:1
+  --> $DIR/lint-dead-code-3.rs:13:8
    |
 LL | struct Foo;
-   | ^^^^^^^^^^^
+   |        ^^^
    |
 note: lint level defined here
   --> $DIR/lint-dead-code-3.rs:3:9
@@ -17,16 +17,16 @@ LL |     fn foo(&self) {
    |     ^^^^^^^^^^^^^
 
 error: function is never used: `bar`
-  --> $DIR/lint-dead-code-3.rs:20:1
+  --> $DIR/lint-dead-code-3.rs:20:4
    |
 LL | fn bar() {
-   | ^^^^^^^^
+   |    ^^^
 
 error: enum is never used: `c_void`
-  --> $DIR/lint-dead-code-3.rs:59:1
+  --> $DIR/lint-dead-code-3.rs:59:6
    |
 LL | enum c_void {}
-   | ^^^^^^^^^^^
+   |      ^^^^^^
 
 error: foreign function is never used: `free`
   --> $DIR/lint-dead-code-3.rs:61:5

src/test/ui/lint/lint-dead-code-4.stderr → src/test/ui/lint/dead-code/lint-dead-code-4.stderr

@@ -27,10 +27,10 @@ LL | |     },
    | |_____^
 
 error: enum is never used: `ABC`
-  --> $DIR/lint-dead-code-4.rs:24:1
+  --> $DIR/lint-dead-code-4.rs:24:6
    |
 LL | enum ABC {
-   | ^^^^^^^^
+   |      ^^^
 
 error: variant is never constructed: `I`
   --> $DIR/lint-dead-code-4.rs:36:5

src/test/ui/lint/lint-dead-code-5.stderr → src/test/ui/lint/dead-code/lint-dead-code-5.stderr

@@ -23,10 +23,10 @@ LL |     Variant6(isize),
    |     ^^^^^^^^^^^^^^^
 
 error: enum is never used: `Enum3`
-  --> $DIR/lint-dead-code-5.rs:18:1
+  --> $DIR/lint-dead-code-5.rs:18:6
    |
 LL | enum Enum3 {
-   | ^^^^^^^^^^
+   |      ^^^^^
 
 error: aborting due to 4 previous errors
 

src/test/ui/lint/dead-code/newline-span.rs

@@ -0,0 +1,19 @@
+#![deny(dead_code)]
+
+fn unused() { //~ error: function is never used:
+    println!("blah");
+}
+
+fn unused2(var: i32) { //~ error: function is never used:
+    println!("foo {}", var);
+}
+
+fn unused3( //~ error: function is never used:
+    var: i32,
+) {
+    println!("bar {}", var);
+}
+
+fn main() {
+    println!("Hello world!");
+}

src/test/ui/lint/dead-code/newline-span.stderr

@@ -0,0 +1,26 @@
+error: function is never used: `unused`
+  --> $DIR/newline-span.rs:3:4
+   |
+LL | fn unused() {
+   |    ^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/newline-span.rs:1:9
+   |
+LL | #![deny(dead_code)]
+   |         ^^^^^^^^^
+
+error: function is never used: `unused2`
+  --> $DIR/newline-span.rs:7:4
+   |
+LL | fn unused2(var: i32) {
+   |    ^^^^^^^
+
+error: function is never used: `unused3`
+  --> $DIR/newline-span.rs:11:4
+   |
+LL | fn unused3(
+   |    ^^^^^^^
+
+error: aborting due to 3 previous errors
+

src/test/ui/lint/lint-dead-code-type-alias.stderr → src/test/ui/lint/dead-code/type-alias.stderr

@@ -1,11 +1,11 @@
 error: type alias is never used: `Unused`
-  --> $DIR/lint-dead-code-type-alias.rs:4:1
+  --> $DIR/type-alias.rs:4:1
    |
 LL | type Unused = u8;
    | ^^^^^^^^^^^^^^^^^
    |
 note: lint level defined here
-  --> $DIR/lint-dead-code-type-alias.rs:1:9
+  --> $DIR/type-alias.rs:1:9
    |
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^

src/test/ui/lint/lint-dead-code-unused-enum.stderr → src/test/ui/lint/dead-code/unused-enum.stderr

@@ -1,27 +1,27 @@
 error: struct is never constructed: `F`
-  --> $DIR/lint-dead-code-unused-enum.rs:3:1
+  --> $DIR/unused-enum.rs:3:8
    |
 LL | struct F;
-   | ^^^^^^^^^
+   |        ^
    |
 note: lint level defined here
-  --> $DIR/lint-dead-code-unused-enum.rs:1:9
+  --> $DIR/unused-enum.rs:1:9
    |
 LL | #![deny(unused)]
    |         ^^^^^^
    = note: `#[deny(dead_code)]` implied by `#[deny(unused)]`
 
 error: struct is never constructed: `B`
-  --> $DIR/lint-dead-code-unused-enum.rs:4:1
+  --> $DIR/unused-enum.rs:4:8
    |
 LL | struct B;
-   | ^^^^^^^^^
+   |        ^
 
 error: enum is never used: `E`
-  --> $DIR/lint-dead-code-unused-enum.rs:6:1
+  --> $DIR/unused-enum.rs:6:6
    |
 LL | enum E {
-   | ^^^^^^
+   |      ^
 
 error: aborting due to 3 previous errors
 

src/test/ui/lint/lint-dead-code-unused-variant.stderr → src/test/ui/lint/dead-code/unused-struct-variant.stderr

@@ -1,11 +1,11 @@
 error: variant is never constructed: `Bar`
-  --> $DIR/lint-dead-code-unused-variant.rs:8:5
+  --> $DIR/unused-struct-variant.rs:8:5
    |
 LL |     Bar(B),
    |     ^^^^^^
    |
 note: lint level defined here
-  --> $DIR/lint-dead-code-unused-variant.rs:1:9
+  --> $DIR/unused-struct-variant.rs:1:9
    |
 LL | #![deny(unused)]
    |         ^^^^^^

src/test/ui/lint/lint-dead-code-variant.stderr → src/test/ui/lint/dead-code/unused-variant.stderr

@@ -1,11 +1,11 @@
 error: variant is never constructed: `Variant1`
-  --> $DIR/lint-dead-code-variant.rs:5:5
+  --> $DIR/unused-variant.rs:5:5
    |
 LL |     Variant1,
    |     ^^^^^^^^
    |
 note: lint level defined here
-  --> $DIR/lint-dead-code-variant.rs:1:9
+  --> $DIR/unused-variant.rs:1:9
    |
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^

src/test/ui/fail-no-dead-code-core.stderr → src/test/ui/lint/dead-code/with-core-crate.stderr

@@ -1,11 +1,11 @@
 error: function is never used: `foo`
-  --> $DIR/fail-no-dead-code-core.rs:7:1
+  --> $DIR/with-core-crate.rs:7:4
    |
 LL | fn foo() {
-   | ^^^^^^^^
+   |    ^^^
    |
 note: lint level defined here
-  --> $DIR/fail-no-dead-code-core.rs:1:9
+  --> $DIR/with-core-crate.rs:1:9
    |
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^