Rollup merge of #141517 - lolbinarycat:rustdoc-doctest-tooltip-ignore-141092, r=notriddle

rustdoc: use descriptive tooltip if doctest is conditionally ignored

fixes https://github.com/rust-lang/rust/issues/141092

here's what it looks like now:
![screenshot](https://github.com/user-attachments/assets/71e679fe-8828-439d-a2ce-b9187ad3aeea)

3 files changed, 53 insertions, 21 deletions

diff --git a/src/librustdoc/html/highlight.rs b/src/librustdoc/html/highlight.rs
index 2db1ea8450c..b2feee36c93 100644
--- a/src/librustdoc/html/highlight.rs
+++ b/src/librustdoc/html/highlight.rs
@@ -6,7 +6,7 @@
 //! Use the `render_with_highlighting` to highlight some rust code.
 
 use std::collections::VecDeque;
-use std::fmt::{Display, Write};
+use std::fmt::{self, Display, Write};
 
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_lexer::{Cursor, FrontmatterAllowed, LiteralKind, TokenKind};
@@ -36,9 +36,10 @@ pub(crate) struct HrefContext<'a, 'tcx> {
 #[derive(Default)]
 pub(crate) struct DecorationInfo(pub(crate) FxIndexMap<&'static str, Vec<(u32, u32)>>);
 
-#[derive(Eq, PartialEq, Clone, Copy)]
+#[derive(Eq, PartialEq, Clone)]
 pub(crate) enum Tooltip {
-    Ignore,
+    IgnoreAll,
+    IgnoreSome(Vec<String>),
     CompileFail,
     ShouldPanic,
     Edition(Edition),
@@ -70,7 +71,7 @@ fn write_header(
         format_args!(
             "<div class=\"example-wrap{}\">",
             match tooltip {
-                Tooltip::Ignore => " ignore",
+                Tooltip::IgnoreAll | Tooltip::IgnoreSome(_) => " ignore",
                 Tooltip::CompileFail => " compile_fail",
                 Tooltip::ShouldPanic => " should_panic",
                 Tooltip::Edition(_) => " edition",
@@ -80,23 +81,29 @@ fn write_header(
     );
 
     if tooltip != Tooltip::None {
-        let edition_code;
-        write_str(
-            out,
-            format_args!(
-                "<a href=\"#\" class=\"tooltip\" title=\"{}\">ⓘ</a>",
-                match tooltip {
-                    Tooltip::Ignore => "This example is not tested",
-                    Tooltip::CompileFail => "This example deliberately fails to compile",
-                    Tooltip::ShouldPanic => "This example panics",
-                    Tooltip::Edition(edition) => {
-                        edition_code = format!("This example runs with edition {edition}");
-                        &edition_code
+        let tooltip = fmt::from_fn(|f| match &tooltip {
+            Tooltip::IgnoreAll => f.write_str("This example is not tested"),
+            Tooltip::IgnoreSome(platforms) => {
+                f.write_str("This example is not tested on ")?;
+                match &platforms[..] {
+                    [] => unreachable!(),
+                    [platform] => f.write_str(platform)?,
+                    [first, second] => write!(f, "{first} or {second}")?,
+                    [platforms @ .., last] => {
+                        for platform in platforms {
+                            write!(f, "{platform}, ")?;
+                        }
+                        write!(f, "or {last}")?;
                     }
-                    Tooltip::None => unreachable!(),
                 }
-            ),
-        );
+                Ok(())
+            }
+            Tooltip::CompileFail => f.write_str("This example deliberately fails to compile"),
+            Tooltip::ShouldPanic => f.write_str("This example panics"),
+            Tooltip::Edition(edition) => write!(f, "This example runs with edition {edition}"),
+            Tooltip::None => unreachable!(),
+        });
+        write_str(out, format_args!("<a href=\"#\" class=\"tooltip\" title=\"{tooltip}\">ⓘ</a>"));
     }
 
     if let Some(extra) = extra_content {
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index ad7dfafd90c..987b92fa4e2 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -320,8 +320,10 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for CodeBlocks<'_, 'a, I> {
             ))
         });
 
-        let tooltip = if ignore != Ignore::None {
-            highlight::Tooltip::Ignore
+        let tooltip = if ignore == Ignore::All {
+            highlight::Tooltip::IgnoreAll
+        } else if let Ignore::Some(platforms) = ignore {
+            highlight::Tooltip::IgnoreSome(platforms)
         } else if compile_fail {
             highlight::Tooltip::CompileFail
         } else if should_panic {
diff --git a/tests/rustdoc/doctest/ignore-sometimes.rs b/tests/rustdoc/doctest/ignore-sometimes.rs
new file mode 100644
index 00000000000..0f8586d221c
--- /dev/null
+++ b/tests/rustdoc/doctest/ignore-sometimes.rs
@@ -0,0 +1,23 @@
+#![crate_name = "foo"]
+
+// test for https://github.com/rust-lang/rust/issues/141092
+
+//@ has 'foo/fn.f.html' '//a[@title="This example is not tested on wasm"]' 'ⓘ'
+/// Example
+///
+/// ```ignore-wasm
+/// let x = 1;
+/// ```
+pub fn f() {}
+
+//@ has 'foo/fn.g.html' '//a[@title="This example is not tested on wasm or windows"]' 'ⓘ'
+/// ```ignore-wasm,ignore-windows
+/// let x = 1;
+/// ```
+pub fn g() {}
+
+//@ has 'foo/fn.h.html' '//a[@title="This example is not tested on wasm, windows, or unix"]' 'ⓘ'
+/// ```ignore-wasm,ignore-windows,ignore-unix
+/// let x = 1;
+/// ```
+pub fn h() {}