Auto merge of #133505 - compiler-errors:rollup-xjp8hdi, r=compiler-errors

Rollup of 12 pull requests

Successful merges:

 - #133042 (btree: add `{Entry,VacantEntry}::insert_entry`)
 - #133070 (Lexer tweaks)
 - #133136 (Support ranges in `<[T]>::get_many_mut()`)
 - #133140 (Inline ExprPrecedence::order into Expr::precedence)
 - #133155 (Yet more `rustc_mir_dataflow` cleanups)
 - #133282 (Shorten the `MaybeUninit` `Debug` implementation)
 - #133326 (Remove the `DefinitelyInitializedPlaces` analysis.)
 - #133362 (No need to re-sort existential preds in relate impl)
 - #133367 (Simplify array length mismatch error reporting (to not try to turn consts into target usizes))
 - #133394 (Bail on more errors in dyn ty lowering)
 - #133410 (target check_consistency: ensure target feature string makes some basic sense)
 - #133435 (miri: disable test_downgrade_observe test on macOS)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 23 insertions, 0 deletions

diff --git a/compiler/rustc_target/src/spec/tests/tests_impl.rs b/compiler/rustc_target/src/spec/tests/tests_impl.rs
index 522b9f837d7..3225cdc759d 100644
--- a/compiler/rustc_target/src/spec/tests/tests_impl.rs
+++ b/compiler/rustc_target/src/spec/tests/tests_impl.rs
@@ -1,5 +1,7 @@
 use std::assert_matches::assert_matches;
 
+use rustc_data_structures::fx::FxHashSet;
+
 use super::super::*;
 
 // Test target self-consistency and JSON encoding/decoding roundtrip.
@@ -173,6 +175,27 @@ impl Target {
             }
             _ => {}
         }
+
+        // Check that the given target-features string makes some basic sense.
+        if !self.features.is_empty() {
+            let mut features_enabled = FxHashSet::default();
+            let mut features_disabled = FxHashSet::default();
+            for feat in self.features.split(',') {
+                if let Some(feat) = feat.strip_prefix("+") {
+                    features_enabled.insert(feat);
+                    if features_disabled.contains(feat) {
+                        panic!("target feature `{feat}` is both enabled and disabled");
+                    }
+                } else if let Some(feat) = feat.strip_prefix("-") {
+                    features_disabled.insert(feat);
+                    if features_enabled.contains(feat) {
+                        panic!("target feature `{feat}` is both enabled and disabled");
+                    }
+                } else {
+                    panic!("target feature `{feat}` is invalid, must start with `+` or `-`");
+                }
+            }
+        }
     }
 
     // Add your target to the whitelist if it has `std` library