fix(plugin_call): set rc to EXIT_SIGNALED_SIGABRT when wasmtime bails out on plugin call (#776)

Fixes #775

134/EXIT_SIGNALED_SIGABRT was chosen as the wasmtime CLI exits with it
executes `unreachable`.

runtime/src/plugin.rs

@@ -867,19 +867,25 @@ impl Plugin {
         let _ = self.timer_tx.send(TimerAction::Stop { id: self.id });
         self.store_needs_reset = name == "_start";
 
-        let mut rc = 0;
+        let mut rc = -1;
         if self.store.get_fuel().is_ok_and(|x| x == 0) {
             res = Err(Error::msg("plugin ran out of fuel"));
-            rc = -1;
         } else {
             // Get extism error
-            self.get_output_after_call().map_err(|x| (x, -1))?;
-            if !results.is_empty() {
-                rc = results[0].i32().unwrap_or(-1);
-                debug!(plugin = self.id.to_string(), "got return code: {}", rc);
+            let output_res = self.get_output_after_call().map_err(|x| (x, -1));
+
+            // Get the return code
+            if output_res.is_ok() && res.is_ok() {
+                rc = 0;
+                if !results.is_empty() {
+                    rc = results[0].i32().unwrap_or(-1);
+                    debug!(plugin = self.id.to_string(), "got return code: {}", rc);
+                }
             }
 
-            if self.output.error_offset != 0 && self.output.error_length != 0 {
+            // on extism error
+            if output_res.is_ok() && self.output.error_offset != 0 && self.output.error_length != 0
+            {
                 let handle = MemoryHandle {
                     offset: self.output.error_offset,
                     length: self.output.error_length,
@@ -904,6 +910,14 @@ impl Plugin {
                         )));
                     }
                 }
+            // on wasmtime error
+            } else if let Err(e) = &res {
+                if e.is::<wasmtime::Trap>() {
+                    rc = 134; // EXIT_SIGNALED_SIGABRT
+                }
+            // if there was an error retrieving the output
+            } else {
+                output_res?;
             }
         }
 

runtime/src/tests/issues.rs

@@ -1,6 +1,7 @@
 use crate::*;
 
 const WASM_EMPTY: &[u8] = include_bytes!("../../../wasm/empty.wasm");
+const WASM_UNREACHABLE: &[u8] = include_bytes!("../../../wasm/unreachable.wasm");
 
 // https://github.com/extism/extism/issues/620
 #[test]
@@ -26,3 +27,31 @@ host_fn!(
         Ok(path.display().to_string())
     }
 );
+
+// https://github.com/extism/extism/issues/775
+#[test]
+fn test_issue_775() {
+    // Load and build plugin
+    let url = Wasm::data(WASM_UNREACHABLE);
+    let manifest = Manifest::new([url]);
+    let mut plugin = PluginBuilder::new(manifest)
+        .with_wasi(true)
+        .build()
+        .unwrap();
+    // Call test method
+    let lock = plugin.instance.clone();
+    let mut lock = lock.lock().unwrap();
+    let res = plugin.raw_call(&mut lock, "do_unreachable", b"", None::<()>);
+    let p = match res {
+        Err(e) => {
+            if e.1 == 0 {
+                Err(e.1)
+            } else {
+                Ok(e.1)
+            }
+        }
+        Ok(code) => Err(code),
+    }
+    .unwrap();
+    println!("{}", p);
+}