Only use layout_for_ptr feature for zerocopy tests

This puts the use of the unstable feature `layout_for_ptr` behind
`all(__ZEROCOPY_INTERNAL_USE_ONLY_NIGHTLY_FEATURES_IN_TESTS, miri)`,
since it is only necessary for zerocopy tests, not for downstream users.

Release 0.8.49.

gherrit-pr-id: Gejcq7kjlhyldvg6gkkxeudox66wbfmi3

Author: erickt

.github/workflows/ci.yml

@@ -523,10 +523,14 @@ jobs:
         THREADS=$(echo "$(nproc) * 2" | bc)
         echo "Running Miri tests with $THREADS threads" | tee -a $GITHUB_STEP_SUMMARY
 
+        # The internal miri tests use unstable rust features, so we want to make sure zerocopy
+        # still compiles without those features for downstream users.
+        RUSTFLAGS="--cfg miri" ./cargo.sh +$TOOLCHAIN
+
         # Run under both the stacked borrows model (default) and under the tree 
         # borrows model to ensure we're compliant with both.
         for EXTRA_FLAGS in "" "-Zmiri-tree-borrows"; do
-          MIRIFLAGS="$MIRIFLAGS $EXTRA_FLAGS" ./cargo.sh +$TOOLCHAIN \
+          MIRIFLAGS="$MIRIFLAGS $EXTRA_FLAGS --cfg __ZEROCOPY_INTERNAL_USE_ONLY_NIGHTLY_FEATURES_IN_TESTS" ./cargo.sh +$TOOLCHAIN \
             miri nextest run \
             --test-threads "$THREADS" \
             --package $CRATE \

Cargo.lock

@@ -15,7 +15,7 @@
 [package]
 edition = "2021"
 name = "zerocopy"
-version = "0.8.48"
+version = "0.8.49"
 authors = [
     "Joshua Liebow-Feeser <joshlf@google.com>",
     "Jack Wrenn <jswrenn@amazon.com>",
@@ -124,13 +124,13 @@ __internal_use_only_features_that_work_on_stable = [
 ]
 
 [dependencies]
-zerocopy-derive = { version = "=0.8.48", path = "zerocopy-derive", optional = true }
+zerocopy-derive = { version = "=0.8.49", path = "zerocopy-derive", optional = true }
 
 # The "associated proc macro pattern" ensures that the versions of zerocopy and
 # zerocopy-derive remain equal, even if the 'derive' feature isn't used.
 # See: https://github.com/matklad/macro-dep-test
 [target.'cfg(any())'.dependencies]
-zerocopy-derive = { version = "=0.8.48", path = "zerocopy-derive" }
+zerocopy-derive = { version = "=0.8.49", path = "zerocopy-derive" }
 
 [dev-dependencies]
 # FIXME(#381) Remove this dependency once we have our own layout gadgets.
@@ -142,4 +142,4 @@ rustversion = "1.0"
 static_assertions = "1.1"
 testutil = { path = "testutil" }
 # In tests, unlike in production, zerocopy-derive is not optional
-zerocopy-derive = { version = "=0.8.48", path = "zerocopy-derive" }
+zerocopy-derive = { version = "=0.8.49", path = "zerocopy-derive" }

Cargo.toml

@@ -324,10 +324,7 @@
 #![cfg_attr(feature = "float-nightly", feature(f16, f128))]
 #![cfg_attr(doc_cfg, feature(doc_cfg))]
 #![cfg_attr(__ZEROCOPY_INTERNAL_USE_ONLY_NIGHTLY_FEATURES_IN_TESTS, feature(coverage_attribute))]
-#![cfg_attr(
-    any(__ZEROCOPY_INTERNAL_USE_ONLY_NIGHTLY_FEATURES_IN_TESTS, miri),
-    feature(layout_for_ptr)
-)]
+#![cfg_attr(__ZEROCOPY_INTERNAL_USE_ONLY_NIGHTLY_FEATURES_IN_TESTS, feature(layout_for_ptr))]
 #![cfg_attr(all(test, __ZEROCOPY_INTERNAL_USE_ONLY_NIGHTLY_FEATURES_IN_TESTS), feature(test))]
 
 // This is a hack to allow zerocopy-derive derives to work in this crate. They

src/lib.rs

@@ -233,7 +233,7 @@ mod _conversions {
             let raw = self.as_inner().as_non_null();
             // SAFETY: `self` satisfies the `Aligned` invariant, so we know that
             // `raw` is validly-aligned for `T`.
-            #[cfg(miri)]
+            #[cfg(all(__ZEROCOPY_INTERNAL_USE_ONLY_NIGHTLY_FEATURES_IN_TESTS, miri))]
             unsafe {
                 crate::util::miri_promise_symbolic_alignment(
                     raw.as_ptr().cast(),
@@ -381,7 +381,7 @@ mod _conversions {
             let mut raw = self.as_inner().as_non_null();
             // SAFETY: `self` satisfies the `Aligned` invariant, so we know that
             // `raw` is validly-aligned for `T`.
-            #[cfg(miri)]
+            #[cfg(all(__ZEROCOPY_INTERNAL_USE_ONLY_NIGHTLY_FEATURES_IN_TESTS, miri))]
             unsafe {
                 crate::util::miri_promise_symbolic_alignment(
                     raw.as_ptr().cast(),

src/pointer/ptr.rs

@@ -56,7 +56,7 @@ impl<T: ?Sized> Clone for SendSyncPhantomData<T> {
     }
 }
 
-#[cfg(miri)]
+#[cfg(all(__ZEROCOPY_INTERNAL_USE_ONLY_NIGHTLY_FEATURES_IN_TESTS, miri))]
 extern "Rust" {
     /// Miri-provided intrinsic that marks the pointer `ptr` as aligned to
     /// `align`.

src/util/mod.rs

@@ -9,7 +9,7 @@
 [package]
 edition = "2021"
 name = "zerocopy-derive"
-version = "0.8.48"
+version = "0.8.49"
 authors = ["Joshua Liebow-Feeser <joshlf@google.com>", "Jack Wrenn <jswrenn@amazon.com>"]
 description = "Custom derive for traits from the zerocopy crate"
 license = "BSD-2-Clause OR Apache-2.0 OR MIT"