rustdoc: Properly detect syntactically invalid doctests (to fix a regression)

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -241,7 +241,7 @@ pub(crate) enum AttributeOrder {
     ///
     /// Attributes are processed from bottom to top, so this raises a warning/error on all the attributes
     /// further above the lowest one:
-    /// ```
+    /// ```ignore (illustrative)
     /// #[stable(since="1.0")] //~ WARNING duplicated attribute
     /// #[stable(since="2.0")]
     /// ```
@@ -252,7 +252,7 @@ pub(crate) enum AttributeOrder {
     ///
     /// Attributes are processed from bottom to top, so this raises a warning/error on all the attributes
     /// below the highest one:
-    /// ```
+    /// ```ignore (illustrative)
     /// #[path="foo.rs"]
     /// #[path="bar.rs"] //~ WARNING duplicated attribute
     /// ```

compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs

@@ -112,10 +112,6 @@ impl Emitter for AnnotateSnippetEmitter {
     fn translator(&self) -> &Translator {
         &self.translator
     }
-
-    fn supports_color(&self) -> bool {
-        false
-    }
 }
 
 fn annotation_level_for_level(level: Level) -> annotate_snippets::level::Level<'static> {

compiler/rustc_errors/src/emitter.rs

@@ -203,11 +203,6 @@ pub trait Emitter {
         true
     }
 
-    /// Checks if we can use colors in the current output stream.
-    fn supports_color(&self) -> bool {
-        false
-    }
-
     fn source_map(&self) -> Option<&SourceMap>;
 
     fn translator(&self) -> &Translator;

tests/rustdoc-ui/doctest/doctest-output-include-fail.stdout

@@ -13,7 +13,15 @@ LL |     let x = 234 // no semicolon here! oh no!
 LL | }
    | - unexpected token
 
-error: aborting due to 1 previous error
+warning: unused variable: `x`
+  --> $DIR/doctest-output-include-fail.md:5:9
+   |
+LL |     let x = 234 // no semicolon here! oh no!
+   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
+   |
+   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
+
+error: aborting due to 1 previous error; 1 warning emitted
 
 Couldn't compile the test.
 
@@ -22,4 +30,3 @@ failures:
 
 test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
 
-all doctests ran in $TIME; merged doctests compilation took $TIME

tests/rustdoc-ui/doctest/no-capture-fail.stderr

@@ -14,5 +14,12 @@ LL |     Input: 123
 LL ~ } }
    |
 
-error: aborting due to 1 previous error
+error[E0601]: `main` function not found in crate `rust_out`
+  --> $DIR/nocapture-fail.rs:10:2
+   |
+LL | }
+   |  ^ consider adding a `main` function to `$DIR/nocapture-fail.rs`
+
+error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0601`.

tests/rustdoc-ui/doctest/recovered-syntax-error.rs

@@ -0,0 +1,9 @@
+// issue: <https://github.com/rust-lang/rust/issues/147999>
+//@ compile-flags: --test
+//@ normalize-stdout: "tests/rustdoc-ui/doctest" -> "$$DIR"
+//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"
+//@ failure-status: 101
+
+//! ```
+//! #[derive(Clone)]
+//! ```

tests/rustdoc-ui/doctest/recovered-syntax-error.stdout

@@ -0,0 +1,22 @@
+
+running 1 test
+test $DIR/recovered-syntax-error.rs - (line 7) ... FAILED
+
+failures:
+
+---- $DIR/recovered-syntax-error.rs - (line 7) stdout ----
+error: expected item after attributes
+  --> $DIR/recovered-syntax-error.rs:8:1
+   |
+LL | #[derive(Clone)]
+   | ^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
+Couldn't compile the test.
+
+failures:
+    $DIR/recovered-syntax-error.rs - (line 7)
+
+test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+