fix(plugins): refuse components that don't link against the host in check and install (#1471)

check_component only compared import names and the API version, so a component
built from unreleased WIT (a function added under @1.0.0) or missing the plugin
world's exports passed `openidea-plugin check` and installing, then failed when
the IDE started it. It now links the component against the host's linker and
reports the missing or mismatched function with what to do.

Closes #1468

Cargo.lock

@@ -1496,7 +1496,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d045de693cb712d0b22c6a64be5b953f67b3ce00ab5ad3dd5d8b441886ab8e1a"
 dependencies = [
  "quote",
- "syn 3.0.9",
+ "syn 2.0.119",
 ]
 
 [[package]]
@@ -3001,7 +3001,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1c48eccd894bd15555b0346470e63491ded94aefe76b3fcb1052084b5a393238"
 dependencies = [
  "bstr",
- "hashbrown 0.17.1",
+ "hashbrown 0.16.1",
 ]
 
 [[package]]
@@ -4504,6 +4504,7 @@ dependencies = [
  "tracing",
  "wasmtime",
  "wasmtime-wasi",
+ "wat",
 ]
 
 [[package]]
@@ -8362,7 +8363,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0d204abcbdf8e88729306a8d0ca01a79d8a49969fe1f84696909d6dbc4321c1a"
 dependencies = [
  "foldhash",
- "hashbrown 0.17.1",
+ "hashbrown 0.16.1",
 ]
 
 [[package]]
@@ -10305,6 +10306,12 @@ version = "1.13.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c6f5d3c3b1bf09027a88a6bc961fc00497d651009560b5463668dc81b0fa87a8"
 
+[[package]]
+name = "unicode-width"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca718471876992059f251e33aafc334346ada08042b7661dd1fe313a9bced557"
+
 [[package]]
 name = "universal-hash"
 version = "0.6.1"
@@ -10825,6 +10832,28 @@ dependencies = [
  "wasmtime",
 ]
 
+[[package]]
+name = "wast"
+version = "258.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b912cfe5696dfaae736e344fc82082dbd63609abbaeca3926466c0b10d9fecc"
+dependencies = [
+ "bumpalo",
+ "leb128fmt",
+ "memchr",
+ "unicode-width",
+ "wasm-encoder",
+]
+
+[[package]]
+name = "wat"
+version = "1.258.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3069154948f5737a8bcd5c55dcdf2c2b59ca776057732e49821167bde268ec6e"
+dependencies = [
+ "wast",
+]
+
 [[package]]
 name = "wayland-backend"
 version = "0.3.17"

crates/ide-plugin/Cargo.toml

@@ -22,3 +22,4 @@ wasmtime-wasi = { version = "49.0.4", default-features = false, features = ["p2"
 [dev-dependencies]
 tempfile.workspace = true
 tokio = { workspace = true, features = ["rt-multi-thread", "macros", "time"] }
+wat = "1.258"

crates/ide-plugin/src/runtime.rs

@@ -211,8 +211,10 @@ impl PluginEngine {
     /// Rejects a component this host can't run, with a message that says what
     /// to do: one importing interfaces outside the plugin API and WASI, or one
     /// built for a plugin API this host doesn't implement (another major, or a
-    /// newer minor). Returns the API version the component was built for
-    /// (`None`: it uses no plugin interface).
+    /// newer minor), or one that doesn't link: an import the host lacks or
+    /// declares with another type (same API version, different WIT), or a
+    /// missing plugin export. Returns the API version the component was built
+    /// for (`None`: it uses no plugin interface).
     pub fn check_component(&self, component: &Component) -> Result<Option<semver::Version>, String> {
         let ty = component.component_type();
         let imports: Vec<String> = ty.imports(&self.engine).map(|(name, _)| name.to_owned()).collect();
@@ -229,10 +231,20 @@ impl PluginEngine {
         if let Some(v) = &built_for {
             check_api(v, &host_api())?;
         }
+        let pre = self.linker.instantiate_pre(component).map_err(|e| link_error(&format!("{e:#}")))?;
+        bindings::PluginIndices::new(&pre).map_err(|e| link_error(&format!("{e:#}")))?;
         Ok(built_for)
     }
 }
 
+/// Explains a component that doesn't link against this host's plugin API.
+fn link_error(detail: &str) -> String {
+    format!(
+        "the component doesn't match the plugin API of this IDE ({API_VERSION}): {detail}. \
+         If it was built for a newer OpenIDEA, update OpenIDEA; otherwise rebuild it with the {API_VERSION} SDK"
+    )
+}
+
 /// Interface names of the plugin API start with this (`openidea:plugin/log@1.0.0`).
 const PLUGIN_PACKAGE_PREFIX: &str = "openidea:plugin/";
 
@@ -542,11 +554,7 @@ impl Runtime {
         arm(&mut store, &setup.limits, setup.limits.timeout).map_err(|e| e.to_string())?;
         let api_hint = |e: wasmtime::Error| {
             let msg = describe_trap(&e, &setup.limits);
-            if msg.contains("openidea:plugin/") {
-                format!("{msg} (the component was built for a different plugin API; this IDE runs API {API_VERSION})")
-            } else {
-                msg
-            }
+            if msg.contains("openidea:plugin/") { link_error(&msg) } else { msg }
         };
         let pre = engine.linker.instantiate_pre(component).map_err(api_hint)?;
         let plugin_indices = bindings::PluginIndices::new(&pre).map_err(api_hint)?;

crates/ide-plugin/tests/check_component.rs

@@ -0,0 +1,43 @@
+//! `PluginEngine::check_component` (what installing and `openidea-plugin check`
+//! run) refuses a component the IDE could not start: every import has to link
+//! against the host, function by function, and the plugin world's exports have
+//! to be there, not only the interface names and their API version.
+
+use ide_plugin::PluginEngine;
+
+fn check(wat: &str) -> Result<Option<semver::Version>, String> {
+    let engine = PluginEngine::new().unwrap();
+    let component = engine.compile_bytes(&wat::parse_str(wat).unwrap()).unwrap();
+    engine.check_component(&component)
+}
+
+#[test]
+fn components_the_host_cannot_link_are_refused() {
+    let cases = [
+        // dengliu.gitlink 0.1.0: functions added to `ui` on an unreleased branch, still at @1.0.0.
+        (
+            "a function the host's interface lacks",
+            r#"(component (import "openidea:plugin/ui@1.0.0" (instance
+                (export "copy-to-clipboard" (func (param "text" string))))))"#,
+            "copy-to-clipboard",
+        ),
+        (
+            "a function with another signature",
+            r#"(component (import "openidea:plugin/ui@1.0.0" (instance
+                (export "show-notification" (func (param "title" string))))))"#,
+            "show-notification",
+        ),
+        (
+            "an interface the host lacks",
+            r#"(component (import "openidea:plugin/clipboard@1.0.0" (instance
+                (export "copy" (func (param "text" string))))))"#,
+            "openidea:plugin/clipboard@1.0.0",
+        ),
+        ("no plugin exports", r#"(component (import "openidea:plugin/ui@1.0.0" (instance)))"#, "lifecycle"),
+    ];
+    for (case, wat, names) in cases {
+        let err = check(wat).expect_err(case);
+        assert!(err.contains(names), "{case}: {err}");
+        assert!(err.contains("update OpenIDEA") && err.contains("rebuild"), "{case}: {err}");
+    }
+}

plugins/README.md

@@ -71,7 +71,8 @@ target through rustup if needed), copies the component to the manifest's
 `wasm` path and runs `check`. `check` validates the package exactly as
 _Install Plugin from Disk…_ would — manifest, every contribution, the SVG
 sanitiser, the component — and that the component imports nothing but the
-plugin API and WASI. It prints what the user will be asked to grant.
+plugin API and WASI and links against the IDE's: every function it imports
+exists with the same signature, and it exports the plugin world. It prints what the user will be asked to grant.
 
 `link` adds the folder to `links.json` in the IDE's plugins directory
 (`$OPENIDEA_PLUGINS_DIR`, default `<app-data>/ai.l0ng.openidea/plugins`). Linked
@@ -944,6 +945,8 @@ only grows:
    its `openidea:plugin/*` imports and exports, `PluginEngine::check_component`).
    Installing and `openidea-plugin check` refuse another major or a newer
    minor with a message that says to update the IDE or rebuild with the SDK.
+   They also link the component, so one that imports a function this host
+   lacks under the same version (built from unreleased WIT) is refused too.
 5. **One version number**: the `wit/` package version, `ENGINE_VERSION` and
    `API_VERSION` agree, and the SDK's `wit/` copy is identical to `wit/`.
 6. **1.x calls are synchronous and pass documents whole.** Host calls block