rustdoc: Don't mark #[target_feature] functions as ⚠

Closes https://www.github.com/rust-lang/rust/issues/142952

Author: aDotInTheVoid

src/librustdoc/html/render/print_item.rs

@@ -469,7 +469,8 @@ fn item_module(cx: &Context<'_>, item: &clean::Item, items: &[clean::Item]) -> i
 
                     let unsafety_flag = match myitem.kind {
                         clean::FunctionItem(_) | clean::ForeignFunctionItem(..)
-                            if myitem.fn_header(tcx).unwrap().is_unsafe() =>
+                            if myitem.fn_header(tcx).unwrap().safety
+                                == hir::HeaderSafety::Normal(hir::Safety::Unsafe) =>
                         {
                             "<sup title=\"unsafe function\">⚠</sup>"
                         }

tests/rustdoc/target-feature.rs

@@ -0,0 +1,38 @@
+#![crate_name = "foo"]
+
+//@ has 'foo/index.html'
+
+//@ has   - '//dl[@class="item-table"]/dt[1]//a' 'f1_safe'
+//@ has   - '//dl[@class="item-table"]/dt[1]//code' 'popcnt'
+//@ count - '//dl[@class="item-table"]/dt[1]//sup' 0
+//@ has   - '//dl[@class="item-table"]/dt[2]//a' 'f2_not_safe'
+//@ has   - '//dl[@class="item-table"]/dt[2]//code' 'avx2'
+//@ count - '//dl[@class="item-table"]/dt[2]//sup' 1
+//@ has   - '//dl[@class="item-table"]/dt[2]//sup' '⚠'
+
+#[target_feature(enable = "popcnt")]
+//@ has 'foo/fn.f1_safe.html'
+//@ has - '//pre[@class="rust item-decl"]' 'pub fn f1_safe()'
+//@ has - '//*[@id="main-content"]/*[@class="item-info"]/*[@class="stab portability"]' \
+//        'Available with target feature popcnt only.'
+pub fn f1_safe() {}
+
+//@ has 'foo/fn.f2_not_safe.html'
+//@ has - '//pre[@class="rust item-decl"]' 'pub unsafe fn f2_not_safe()'
+//@ has - '//*[@id="main-content"]/*[@class="item-info"]/*[@class="stab portability"]' \
+//        'Available with target feature avx2 only.'
+#[target_feature(enable = "avx2")]
+pub unsafe fn f2_not_safe() {}
+
+//@ has 'foo/fn.f3_multifeatures_in_attr.html'
+//@ has - '//*[@id="main-content"]/*[@class="item-info"]/*[@class="stab portability"]' \
+//        'Available on target features popcnt and avx2 only.'
+#[target_feature(enable = "popcnt", enable = "avx2")]
+pub fn f3_multifeatures_in_attr() {}
+
+//@ has 'foo/fn.f4_multi_attrs.html'
+//@ has - '//*[@id="main-content"]/*[@class="item-info"]/*[@class="stab portability"]' \
+//        'Available on target features popcnt and avx2 only.'
+#[target_feature(enable = "popcnt")]
+#[target_feature(enable = "avx2")]
+pub fn f4_multi_attrs() {}