Fix bug in validate_cast_and_convert_metadata

.github/workflows/ci.yml

@@ -150,7 +150,12 @@ jobs:
       if: contains(matrix.target, 'i686')
 
     - name: Run tests
-      run: ./cargo.sh +${{ matrix.toolchain }} test --package ${{ matrix.crate }} --target ${{ matrix.target }} ${{ matrix.features }} --verbose
+      run: |
+        ./cargo.sh +${{ matrix.toolchain }} test \
+          --package ${{ matrix.crate }} \
+          --target ${{ matrix.target }} \
+          ${{ matrix.features }} \
+          --verbose
       # Only run tests when targetting x86 (32- or 64-bit) - we're executing on
       # x86_64, so we can't run tests for any non-x86 target.
       #
@@ -163,14 +168,24 @@ jobs:
         # Run under both the stacked borrows model (default) and under the tree 
         # borrows model to ensure we're compliant with both.
         for EXTRA_FLAGS in "" "-Zmiri-tree-borrows"; do
-          # Skip the `ui` test since it invokes the compiler, which we can't do from
-          # Miri (and wouldn't want to do anyway).
+          # On `--skip ui`: Skip the `ui` test since it invokes the compiler,
+          # which we can't do from Miri (and wouldn't want to do anyway).
+          #
+          # On `matrix.features == '--all-features': We mark tests which are
+          # particularly expensive to run under Miri as
+          # `#[cfg_attr(miri, ignore)]`. We want to run them once per
+          # toolchain/target combination, but not once per feature set so we
+          # keep the expensive computation to a minimum.
+          #
+          # TODO(#391): Optimize these tests.
           MIRIFLAGS="$MIRIFLAGS $EXTRA_FLAGS" ./cargo.sh +${{ matrix.toolchain }} \
             miri test \
             --package ${{ matrix.crate }} \
             --target ${{ matrix.target }} \
             ${{ matrix.features }} \
-            -- --skip ui
+            -- --skip ui \
+            ${{ matrix.features == '--all-features' && '--ignored' || '' }}
+
         done
       # Only nightly has a working Miri, so we skip installing on all other
       # toolchains.

cargo.sh

@@ -55,6 +55,10 @@ function lookup-version {
   esac
 }
 
+function get-rustflags {
+  [ "$1" == nightly ] && echo "--cfg __INTERNAL_USE_ONLY_NIGHLTY_FEATURES_IN_TESTS"
+}
+
 case "$1" in
   # cargo.sh --version <toolchain-name>
   --version)
@@ -67,14 +71,14 @@ case "$1" in
     for toolchain in msrv stable nightly; do
       echo "[cargo.sh] running with toolchain: $toolchain" >&2
       TOOLCHAIN="$(lookup-version $toolchain)"
-      cargo "+$TOOLCHAIN" ${@:2}
+      RUSTFLAGS="$(get-rustflags $toolchain)" cargo "+$TOOLCHAIN" ${@:2}
     done
     exit 0
     ;;
   # cargo.sh +<toolchain-name> [...]
   +*)
     TOOLCHAIN="$(lookup-version ${1:1})"
-    cargo "+$TOOLCHAIN" ${@:2}
+    RUSTFLAGS="$(get-rustflags ${1:1})" cargo "+$TOOLCHAIN" ${@:2}
     ;;
   *)
     print-usage-and-exit