fix mismatch in stability attributes error in wit-parser (#2076)

When a new interface is marked as @unstable (feature = somefeaturegate) and it uses a stable type from another package via use package:interface/type.{name} the resulting package should be able to be imported into other packages that use it. The use case for this is adding a unstable interface such as wasi-tls to wasi-cli.  Once we get to resolve_include's processing we've already verified that everything checks out from a feature/version perspective for those features. i.e. we can't be trying to consolidate an interface type with a feature that hasn't already been resolved.

Signed-off-by: James Sturtevant <[email protected]>

Author: jsturtevant

crates/wit-parser/src/lib.rs

@@ -1176,18 +1176,21 @@ fn find_futures_and_streams(resolve: &Resolve, ty: Type, results: &mut Vec<TypeI
 ///
 /// This is added for WebAssembly/component-model#332 where @since and @unstable
 /// annotations were added to WIT.
-#[derive(Debug, Clone, PartialEq, Eq)]
+///
+/// The order of the of enum values is significant since it is used with Ord and PartialOrd
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde_derive::Deserialize, Serialize))]
 #[cfg_attr(feature = "serde", serde(rename_all = "kebab-case"))]
 pub enum Stability {
-    /// `@since(version = 1.2.3)`
+    /// This item does not have either `@since` or `@unstable`.
+    Unknown,
+
+    /// `@unstable(feature = foo)`
     ///
-    /// This item is explicitly tagged with `@since` as stable since the
-    /// specified version.  This may optionally have a feature listed as well.
-    Stable {
-        #[cfg_attr(feature = "serde", serde(serialize_with = "serialize_version"))]
-        #[cfg_attr(feature = "serde", serde(deserialize_with = "deserialize_version"))]
-        since: Version,
+    /// This item is explicitly tagged `@unstable`. A feature name is listed and
+    /// this item is excluded by default in `Resolve` unless explicitly enabled.
+    Unstable {
+        feature: String,
         #[cfg_attr(
             feature = "serde",
             serde(
@@ -1200,12 +1203,14 @@ pub enum Stability {
         deprecated: Option<Version>,
     },
 
-    /// `@unstable(feature = foo)`
+    /// `@since(version = 1.2.3)`
     ///
-    /// This item is explicitly tagged `@unstable`. A feature name is listed and
-    /// this item is excluded by default in `Resolve` unless explicitly enabled.
-    Unstable {
-        feature: String,
+    /// This item is explicitly tagged with `@since` as stable since the
+    /// specified version.  This may optionally have a feature listed as well.
+    Stable {
+        #[cfg_attr(feature = "serde", serde(serialize_with = "serialize_version"))]
+        #[cfg_attr(feature = "serde", serde(deserialize_with = "deserialize_version"))]
+        since: Version,
         #[cfg_attr(
             feature = "serde",
             serde(
@@ -1217,9 +1222,6 @@ pub enum Stability {
         )]
         deprecated: Option<Version>,
     },
-
-    /// This item does not have either `@since` or `@unstable`.
-    Unknown,
 }
 
 impl Stability {

crates/wit-parser/src/resolve.rs

@@ -3411,7 +3411,7 @@ impl Remap {
                         },
                     ) => {
                         assert_eq!(*aid, *bid);
-                        update_stability(astability, bstability)?;
+                        merge_stability(astability, bstability)?;
                     }
                     (WorldItem::Interface { .. }, _) => unreachable!(),
                     (WorldItem::Function(_), _) => unreachable!(),
@@ -3837,7 +3837,28 @@ fn update_stability(from: &Stability, into: &mut Stability) -> Result<()> {
 
     // Failing all that this means that the two attributes are different so
     // generate an error.
-    bail!("mismatch in stability attributes")
+    bail!("mismatch in stability from '{:?}' to '{:?}'", from, into)
+}
+
+/// Compares the two attributes and if the `from` is more stable than the `into` then
+/// it will elevate the `into` to the same stability.  
+/// This should be used after its already been confirmed that the types are the same and
+/// should be apart of the component because versions/features are enabled.
+fn merge_stability(from: &Stability, into: &mut Stability) -> Result<()> {
+    // If the two stability annotations are equal then
+    // there's nothing to do here.
+    if from == into {
+        return Ok(());
+    }
+
+    // if the from is more stable elevate stability of into
+    if from > into {
+        *into = from.clone();
+        return Ok(());
+    }
+
+    // otherwise `into`` already has higher stability
+    return Ok(());
 }
 
 /// An error that can be returned during "world elaboration" during various

crates/wit-parser/tests/ui/gated-include-use-with-stable.wit

@@ -0,0 +1,75 @@
+package wasmtime:test;
+
+world test{
+    @unstable(feature = active)
+    include wasi:unstable/imports@0.2.3; 
+    include wasi:foo/imports@0.2.3;
+} 
+
+world test-ordered{
+    include wasi:foo/imports@0.2.3;
+    @unstable(feature = active)
+    include wasi:unstable/imports@0.2.3; 
+} 
+
+package wasi:unstable@0.2.3 {
+    @unstable(feature = active)
+    world imports {
+        @unstable(feature = active)
+        use wasi:dep2/[email protected].{stable-resource};
+        @unstable(feature = active)
+        use wasi:dep-unversioned/unversioned.{unversioned-resource};
+        @unstable(feature = active)
+        use wasi:dep-unstable/unstable.{unstable-resource};
+    }
+}
+
+package wasi:foo@0.2.3 {
+    @since(version = 0.2.0)
+    world imports {
+        @since(version = 0.2.0)
+        include wasi:dep2/[email protected];
+        include wasi:dep-unversioned/imports;
+        include wasi:dep-unstable/imports;
+    }
+}
+
+package wasi:dep2@0.2.3 {
+    @since(version = 0.2.0)
+    world imports {
+        @since(version = 0.2.0)
+        import stable;
+    }
+    @since(version = 0.2.1)
+    interface stable {
+        resource stable-resource {
+        }
+    }
+}
+
+package wasi:dep-unversioned{
+    world imports {
+        import unversioned;
+    }
+    interface unversioned {
+        resource unversioned-resource {
+
+        }
+    }
+}
+
+package wasi:dep-unstable{
+    @unstable(feature = active)
+    world imports {
+        @unstable(feature = active)
+        import unstable;
+    }
+    @unstable(feature = active)
+    interface unstable {
+        @unstable(feature = active)
+        resource unstable-resource {
+
+        }
+    }
+}
+