Merge pull request #425 from filecoin-project/feat/wasmtime-config

Set some wasmtime config settings

Author: Stebalien

fvm/src/machine/engine.rs

@@ -17,7 +17,48 @@ pub struct Engine(Arc<EngineInner>);
 
 impl Default for Engine {
     fn default() -> Self {
-        Engine::new(&wasmtime::Config::default()).unwrap()
+        let mut c = wasmtime::Config::default();
+
+        // c.max_wasm_stack(); https://github.com/filecoin-project/ref-fvm/issues/424
+
+        // wasmtime default: false
+        c.wasm_threads(false);
+
+        // wasmtime default: true
+        c.wasm_simd(false);
+
+        // wasmtime default: false
+        c.wasm_multi_memory(false);
+
+        // wasmtime default: false
+        c.wasm_memory64(false);
+
+        // wasmtime default: true
+        c.wasm_bulk_memory(true);
+
+        // wasmtime default: false
+        c.wasm_module_linking(false);
+
+        // wasmtime default: true
+        c.wasm_multi_value(false); // ??
+
+        // wasmtime default: depends on the arch
+        // > This is true by default on x86-64, and false by default on other architectures.
+        c.wasm_reference_types(false);
+
+        // wasmtime default: false
+        //
+        // from wasmtime docs:
+        // > When Cranelift is used as a code generation backend this will
+        // > configure it to replace NaNs with a single canonical value. This
+        // > is useful for users requiring entirely deterministic WebAssembly
+        // > computation. This is not required by the WebAssembly spec, so it is
+        // > not enabled by default.
+        c.cranelift_nan_canonicalization(true);
+
+        // c.cranelift_opt_level(Speed); ?
+
+        Engine::new(&c).unwrap()
     }
 }