make cache consistency checks into regular debug assertions

Cargo.toml

@@ -54,8 +54,6 @@ harness = false
 
 [features]
 default = ["stack-cache"]
-# Will be enabled on CI via `--all-features`.
-expensive-debug-assertions = []
 stack-cache = []
 
 [profile.dev]

ci.sh

@@ -5,11 +5,11 @@ set -x
 # Determine configuration
 export RUSTFLAGS="-D warnings -C debug-assertions -C debuginfo=1"
 export CARGO_INCREMENTAL=0
-export CARGO_EXTRA_FLAGS="--all-features" # in particular, expensive-debug-assertions
+export CARGO_EXTRA_FLAGS="--all-features"
 
 # Prepare
 echo "Build and install miri"
-CARGO_EXTRA_FLAGS="" ./miri install # implicitly locked -- and the *installed* Miri does *not* get the expensive-debug-assertions feature
+RUSTFLAGS="" ./miri install # implicitly locked, and explicitly without debug assertions
 ./miri build --all-targets --locked # the build that all the `./miri test` below will use
 echo
 

src/stacked_borrows/stack.rs

@@ -82,7 +82,7 @@ impl<'tcx> Stack {
     /// Panics if any of the caching mechanisms have broken,
     /// - The StackCache indices don't refer to the parallel items,
     /// - There are no Unique items outside of first_unique..last_unique
-    #[cfg(feature = "expensive-debug-assertions")]
+    #[cfg(debug_assertions)]
     fn verify_cache_consistency(&self) {
         // Only a full cache needs to be valid. Also see the comments in find_granting_cache
         // and set_unknown_bottom.
@@ -115,7 +115,7 @@ impl<'tcx> Stack {
         tag: SbTagExtra,
         exposed_tags: &FxHashSet<SbTag>,
     ) -> Result<Option<usize>, ()> {
-        #[cfg(feature = "expensive-debug-assertions")]
+        #[cfg(debug_assertions)]
         self.verify_cache_consistency();
 
         let SbTagExtra::Concrete(tag) = tag else {
@@ -247,7 +247,7 @@ impl<'tcx> Stack {
         // This primes the cache for the next access, which is almost always the just-added tag.
         self.cache.add(new_idx, new);
 
-        #[cfg(feature = "expensive-debug-assertions")]
+        #[cfg(debug_assertions)]
         self.verify_cache_consistency();
     }
 
@@ -325,7 +325,7 @@ impl<'tcx> Stack {
             self.unique_range.end = self.unique_range.end.min(disable_start + 1);
         }
 
-        #[cfg(feature = "expensive-debug-assertions")]
+        #[cfg(debug_assertions)]
         self.verify_cache_consistency();
 
         Ok(())
@@ -380,7 +380,7 @@ impl<'tcx> Stack {
             self.unique_range = 0..0;
         }
 
-        #[cfg(feature = "expensive-debug-assertions")]
+        #[cfg(debug_assertions)]
         self.verify_cache_consistency();
         Ok(())
     }