Remove Engine trait

Makefile

@@ -9,22 +9,22 @@ SHELL=/usr/bin/env bash
 
 # The matrix is the product of the following columns:
 #
-# |------------|-----------|----------|--------------|-------|
+# |------------|----------|--------------|-------|
-# | Compiler   ⨯ Engine    ⨯ Platform ⨯ Architecture ⨯ libc  |
+# | Compiler   ⨯ Platform ⨯ Architecture ⨯ libc  |
-# |------------|-----------|----------|--------------|-------|
+# |------------|----------|--------------|-------|
-# | Cranelift  | Universal | Linux    | amd64        | glibc |
+# | Cranelift  | Linux    | amd64        | glibc |
-# | LLVM       |           | Darwin   | aarch64      | musl  |
+# | LLVM       | Darwin   | aarch64      | musl  |
-# | Singlepass |           | Windows  |              |       |
+# | Singlepass | Windows  |              |       |
-# |------------|-----------|----------|--------------|-------|
+# |------------|----------|--------------|-------|
 #
 # Here is what works and what doesn't:
 #
-# * Cranelift with the Universal engine works everywhere,
+# * Cranelift works everywhere,
 #
-# * LLVM with the Universal engine works on Linux+Darwin/`amd64`,
+# * LLVM works on Linux+Darwin/`amd64`,
 #   but it doesn't work on */`aarch64` or Windows/*.
 #
-# * Singlepass with the Universal engine works on Linux+Darwin/`amd64`, but
+# * Singlepass works on Linux+Darwin/`amd64`, but
 #   it doesn't work on */`aarch64` or Windows/*.
 #
 # * Windows isn't tested on `aarch64`, that's why we consider it's not

fuzz/fuzz_targets/deterministic.rs

@@ -2,7 +2,7 @@
 
 use libfuzzer_sys::{arbitrary, arbitrary::Arbitrary, fuzz_target};
 use wasm_smith::{Config, ConfiguredModule};
-use wasmer::{CompilerConfig, Engine, Module, Store};
+use wasmer::{CompilerConfig, Module, Store, UniversalEngine};
 use wasmer_compiler::Universal;
 use wasmer_compiler_cranelift::Cranelift;
 use wasmer_compiler_llvm::LLVM;
@@ -23,8 +23,8 @@ impl Config for NoImportsConfig {
     }
 }
 
-fn compile_and_compare(name: &str, engine: impl Engine, wasm: &[u8]) {
+fn compile_and_compare(name: &str, engine: UniversalEngine, wasm: &[u8]) {
-    let mut store = Store::new_with_engine(&engine);
+    let store = Store::new_with_engine(&engine);
 
     // compile for first time
     let module = Module::new(&store, wasm).unwrap();

lib/api/src/sys/mod.rs

@@ -36,7 +36,7 @@ pub use target_lexicon::{Architecture, CallingConvention, OperatingSystem, Tripl
 pub use wasmer_compiler::{
     wasmparser, CompilerConfig, FunctionMiddleware, MiddlewareReaderState, ModuleMiddleware,
 };
-pub use wasmer_compiler::{Engine, Features, FrameInfo, LinkError, RuntimeError, Tunables};
+pub use wasmer_compiler::{Features, FrameInfo, LinkError, RuntimeError, Tunables};
 pub use wasmer_derive::ValueType;
 pub use wasmer_types::is_wasm;
 pub use wasmer_types::{

lib/api/src/sys/store.rs

@@ -1,12 +1,11 @@
 use crate::sys::tunables::BaseTunables;
 use std::fmt;
-use std::sync::Arc;
+use std::sync::{Arc, RwLock};
 #[cfg(feature = "compiler")]
 use wasmer_compiler::CompilerConfig;
 #[cfg(feature = "compiler")]
-use wasmer_compiler::Universal;
+use wasmer_compiler::{Tunables, Universal, UniversalEngine};
-use wasmer_compiler::{Engine, Tunables};
+use wasmer_vm::{init_traps, TrapHandler, TrapHandlerFn};
-use wasmer_vm::{init_traps, TrapHandlerFn};
 
 use wasmer_vm::StoreObjects;
 
@@ -15,7 +14,7 @@ use wasmer_vm::StoreObjects;
 /// wrap the actual context in a box.
 pub(crate) struct StoreInner {
     pub(crate) objects: StoreObjects,
-    pub(crate) engine: Arc<dyn Engine + Send + Sync>,
+    pub(crate) engine: Arc<UniversalEngine>,
     pub(crate) tunables: Box<dyn Tunables + Send + Sync>,
     pub(crate) trap_handler: Option<Box<TrapHandlerFn<'static>>>,
 }
@@ -32,6 +31,8 @@ pub(crate) struct StoreInner {
 /// Spec: <https://webassembly.github.io/spec/core/exec/runtime.html#store>
 pub struct Store {
     pub(crate) inner: Box<StoreInner>,
+    engine: Arc<UniversalEngine>,
+    trap_handler: Arc<RwLock<Option<Box<TrapHandlerFn<'static>>>>>,
 }
 
 impl Store {
@@ -43,10 +44,7 @@ impl Store {
     }
 
     /// Creates a new `Store` with a specific [`Engine`].
-    pub fn new_with_engine<E>(engine: &E) -> Self
+    pub fn new_with_engine(engine: &UniversalEngine) -> Self {
-    where
-        E: Engine + ?Sized,
-    {
         Self::new_with_tunables(engine, BaseTunables::for_target(engine.target()))
     }
 
@@ -56,10 +54,10 @@ impl Store {
     }
 
     /// Creates a new `Store` with a specific [`Engine`] and [`Tunables`].
-    pub fn new_with_tunables<E>(engine: &E, tunables: impl Tunables + Send + Sync + 'static) -> Self
+    pub fn new_with_tunables(
-    where
+        engine: &UniversalEngine,
-        E: Engine + ?Sized,
+        tunables: impl Tunables + Send + Sync + 'static,
-    {
+    ) -> Self {
         // Make sure the signal handlers are installed.
         // This is required for handling traps.
         init_traps();
@@ -71,6 +69,41 @@ impl Store {
                 tunables: Box::new(tunables),
                 trap_handler: None,
             }),
+            engine: engine.cloned(),
+            trap_handler: Arc::new(RwLock::new(None)),
+        }
+    }
+
+    /// Returns the [`Tunables`].
+    pub fn tunables(&self) -> &dyn Tunables {
+        self.inner.tunables.as_ref()
+    }
+
+    /// Returns the [`Engine`].
+    pub fn engine(&self) -> &Arc<UniversalEngine> {
+        &self.engine
+    }
+
+    /// Checks whether two stores are identical. A store is considered
+    /// equal to another store if both have the same engine. The
+    /// tunables are excluded from the logic.
+    pub fn same(a: &Self, b: &Self) -> bool {
+        a.engine.id() == b.engine.id()
+    }
+}
+
+impl PartialEq for Store {
+    fn eq(&self, other: &Self) -> bool {
+        Self::same(self, other)
+    }
+}
+
+unsafe impl TrapHandler for Store {
+    fn custom_trap_handler(&self, call: &dyn Fn(&TrapHandlerFn) -> bool) -> bool {
+        if let Some(handler) = self.trap_handler.read().unwrap().as_ref() {
+            call(handler)
+        } else {
+            false
         }
     }
 }
@@ -109,7 +142,7 @@ impl Default for Store {
         }
 
         #[allow(unreachable_code, unused_mut)]
-        fn get_engine(mut config: impl CompilerConfig + 'static) -> impl Engine + Send + Sync {
+        fn get_engine(mut config: impl CompilerConfig + 'static) -> UniversalEngine {
             cfg_if::cfg_if! {
                 if #[cfg(feature = "default-universal")] {
                     wasmer_compiler::Universal::new(config)
@@ -165,7 +198,7 @@ impl<'a> StoreRef<'a> {
     }
 
     /// Returns the [`Engine`].
-    pub fn engine(&self) -> &Arc<dyn Engine + Send + Sync> {
+    pub fn engine(&self) -> &Arc<UniversalEngine> {
         &self.inner.engine
     }
 
@@ -198,7 +231,7 @@ impl<'a> StoreMut<'a> {
     }
 
     /// Returns the [`Engine`].
-    pub fn engine(&self) -> &Arc<dyn Engine + Send + Sync> {
+    pub fn engine(&self) -> &Arc<UniversalEngine> {
         &self.inner.engine
     }
 

lib/c-api/src/wasm_c_api/engine.rs

@@ -12,9 +12,8 @@ use super::unstable::target_lexicon::wasmer_target_t;
 use crate::error::update_last_error;
 use cfg_if::cfg_if;
 use std::sync::Arc;
-use wasmer_api::Engine;
 #[cfg(feature = "universal")]
-use wasmer_compiler::Universal;
+use wasmer_compiler::{Universal, UniversalEngine};
 
 /// Kind of compilers that can be used by the engines.
 ///
@@ -263,7 +262,7 @@ pub extern "C" fn wasm_config_set_engine(config: &mut wasm_config_t, engine: was
 /// cbindgen:ignore
 #[repr(C)]
 pub struct wasm_engine_t {
-    pub(crate) inner: Arc<dyn Engine + Send + Sync>,
+    pub(crate) inner: Arc<UniversalEngine>,
 }
 
 #[cfg(feature = "compiler")]
@@ -296,7 +295,7 @@ cfg_if! {
         #[no_mangle]
         pub extern "C" fn wasm_engine_new() -> Box<wasm_engine_t> {
             let compiler_config: Box<dyn CompilerConfig> = get_default_compiler_config();
-            let engine: Arc<dyn Engine + Send + Sync> = Arc::new(Universal::new(compiler_config).engine());
+            let engine: Arc<UniversalEngine> = Arc::new(Universal::new(compiler_config).engine());
             Box::new(wasm_engine_t { inner: engine })
         }
     } else if #[cfg(feature = "universal")] {
@@ -309,7 +308,7 @@ cfg_if! {
         /// cbindgen:ignore
         #[no_mangle]
         pub extern "C" fn wasm_engine_new() -> Box<wasm_engine_t> {
-            let engine: Arc<dyn Engine + Send + Sync> = Arc::new(Universal::headless().engine());
+            let engine: Arc<UniversalEngine> = Arc::new(Universal::headless().engine());
             Box::new(wasm_engine_t { inner: engine })
         }
     } else {
@@ -419,10 +418,11 @@ pub extern "C" fn wasm_engine_new_with_config(
                 compiler_config.canonicalize_nans(true);
             }
 
-            let inner: Arc<dyn Engine + Send + Sync> = match config.engine {
+            #[cfg(not(feature = "universal"))]
-                wasmer_engine_t::UNIVERSAL => {
+            return return_with_error("Wasmer has not been compiled with the `universal` feature.");
-                    cfg_if! {
+            #[cfg(feature = "universal")]
-                        if #[cfg(feature = "universal")] {
+            let inner: Arc<UniversalEngine> =
+                         {
                             let mut builder = Universal::new(compiler_config);
 
                             if let Some(target) = config.target {
@@ -434,16 +434,10 @@ pub extern "C" fn wasm_engine_new_with_config(
                             }
 
                             Arc::new(builder.engine())
-                        } else {
-                            return return_with_error("Wasmer has not been compiled with the `universal` feature.");
-                        }
-                    }
-                },
                         };
             Some(Box::new(wasm_engine_t { inner }))
         } else {
-            let inner: Arc<dyn Engine + Send + Sync> = match config.engine {
+            let inner: Arc<UniversalEngine> =
-                wasmer_engine_t::UNIVERSAL => {
                     cfg_if! {
                         if #[cfg(feature = "universal")] {
                             let mut builder = Universal::headless();
@@ -460,8 +454,6 @@ pub extern "C" fn wasm_engine_new_with_config(
                         } else {
                             return return_with_error("Wasmer has not been compiled with the `universal` feature.");
                         }
-                    }
-                },
                     };
             Some(Box::new(wasm_engine_t { inner }))
         }

lib/cli-compiler/src/commands/compile.rs

@@ -1,4 +1,4 @@
-use crate::store::{EngineType, StoreOptions};
+use crate::store::StoreOptions;
 use crate::warning;
 use anyhow::{Context, Result};
 use std::path::{Path, PathBuf};
@@ -39,15 +39,8 @@ impl Compile {
             .context(format!("failed to compile `{}`", self.path.display()))
     }
 
-    pub(crate) fn get_recommend_extension(
+    pub(crate) fn get_recommend_extension(target_triple: &Triple) -> Result<&'static str> {
-        engine_type: &EngineType,
+        Ok(wasmer_compiler::UniversalArtifactBuild::get_default_extension(target_triple))
-        target_triple: &Triple,
-    ) -> Result<&'static str> {
-        Ok(match engine_type {
-            EngineType::Universal => {
-                wasmer_compiler::UniversalArtifactBuild::get_default_extension(target_triple)
-            }
-        })
     }
 
     fn inner_execute(&self) -> Result<()> {
@@ -66,14 +59,13 @@ impl Compile {
                 Target::new(target_triple.clone(), features)
             })
             .unwrap_or_default();
-        let (mut engine, engine_type, compiler_type) =
+        let (mut engine, compiler_type) = self.store.get_engine_for_target(target.clone())?;
-            self.store.get_engine_for_target(target.clone())?;
         let output_filename = self
             .output
             .file_stem()
             .map(|osstr| osstr.to_string_lossy().to_string())
             .unwrap_or_default();
-        let recommended_extension = Self::get_recommend_extension(&engine_type, target.triple())?;
+        let recommended_extension = Self::get_recommend_extension(target.triple())?;
         match self.output.extension() {
             Some(ext) => {
                 if ext != recommended_extension {
@@ -86,7 +78,6 @@ impl Compile {
         }
         let tunables = self.store.get_tunables_for_target(&target)?;
 
-        println!("Engine: {}", engine_type.to_string());
         println!("Compiler: {}", compiler_type.to_string());
         println!("Target: {}", target.triple());
 

lib/cli-compiler/src/commands/validate.rs

@@ -27,7 +27,7 @@ impl Validate {
             Triple::from_str("x86_64-linux-gnu").unwrap(),
             CpuFeature::SSE2 | CpuFeature::AVX,
         );
-        let (engine, _engine_type, _compiler_type) = self.store.get_engine_for_target(target)?;
+        let (engine, _compiler_type) = self.store.get_engine_for_target(target)?;
         let module_contents = std::fs::read(&self.path)?;
         if !is_wasm(&module_contents) {
             bail!("`wasmer validate` only validates WebAssembly files");

lib/cli-compiler/src/store.rs

@@ -172,14 +172,10 @@ impl CompilerOptions {
         &self,
         target: Target,
         compiler_config: Box<dyn CompilerConfig>,
-        engine_type: EngineType,
     ) -> Result<UniversalEngineBuilder> {
         let features = self.get_features(compiler_config.default_features_for_target(&target))?;
-        let engine: UniversalEngineBuilder = match engine_type {
+        let engine: UniversalEngineBuilder =
-            EngineType::Universal => {
+            UniversalEngineBuilder::new(Some(compiler_config.compiler()), features);
-                UniversalEngineBuilder::new(Some(compiler_config.compiler()), features)
-            }
-        };
 
         Ok(engine)
     }
@@ -361,48 +357,23 @@ impl ToString for CompilerType {
     }
 }
 
-/// The engine used for the store
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub enum EngineType {
-    /// Universal Engine
-    Universal,
-}
-
-impl ToString for EngineType {
-    fn to_string(&self) -> String {
-        match self {
-            Self::Universal => "universal".to_string(),
-        }
-    }
-}
-
 impl StoreOptions {
     /// Get a UniversalEngineBulder for the Target
     pub fn get_engine_for_target(
         &self,
         target: Target,
-    ) -> Result<(UniversalEngineBuilder, EngineType, CompilerType)> {
+    ) -> Result<(UniversalEngineBuilder, CompilerType)> {
         let (compiler_config, compiler_type) = self.compiler.get_compiler_config()?;
-        let (engine, engine_type) = self.get_engine_with_compiler(target, compiler_config)?;
+        let engine = self.get_engine_with_compiler(target, compiler_config)?;
-        Ok((engine, engine_type, compiler_type))
+        Ok((engine, compiler_type))
-    }
-
-    /// Get default EngineType
-    pub fn get_engine(&self) -> Result<EngineType> {
-        Ok(EngineType::Universal)
     }
 
     fn get_engine_with_compiler(
         &self,
         target: Target,
         compiler_config: Box<dyn CompilerConfig>,
-    ) -> Result<(UniversalEngineBuilder, EngineType)> {
+    ) -> Result<UniversalEngineBuilder> {
-        let engine_type = self.get_engine()?;
+        self.compiler.get_engine_by_type(target, compiler_config)
-        let engine = self
-            .compiler
-            .get_engine_by_type(target, compiler_config, engine_type)?;
-
-        Ok((engine, engine_type))
     }
 
     /// Get (Subset)Tunables for the Target

lib/cli/src/store.rs

@@ -112,9 +112,9 @@ impl CompilerOptions {
         &self,
         target: Target,
         compiler_config: Box<dyn CompilerConfig>,
-    ) -> Result<Box<dyn Engine + Send + Sync>> {
+    ) -> Result<Box<UniversalEngine>> {
         let features = self.get_features(compiler_config.default_features_for_target(&target))?;
-        let engine: Box<dyn Engine + Send + Sync> = Box::new(
+        let engine: Box<UniversalEngine> = Box::new(
             wasmer_compiler::Universal::new(compiler_config)
                 .features(features)
                 .target(target)
@@ -321,7 +321,7 @@ impl StoreOptions {
         &self,
         target: Target,
         compiler_config: Box<dyn CompilerConfig>,
-    ) -> Result<Box<dyn Engine + Send + Sync>> {
+    ) -> Result<Box<UniversalEngine>> {
         let engine = self.compiler.get_engine(target, compiler_config)?;
 
         Ok(engine)
@@ -331,8 +331,8 @@ impl StoreOptions {
 // If we don't have a compiler, but we have an engine
 #[cfg(not(feature = "compiler"))]
 impl StoreOptions {
-    fn get_engine_headless(&self) -> Result<Arc<dyn Engine + Send + Sync>> {
+    fn get_engine_headless(&self) -> Result<Arc<UniversalEngine>> {
-        let engine: Arc<dyn Engine + Send + Sync> =
+        let engine: Arc<UniversalEngine> =
             Arc::new(wasmer_compiler::Universal::headless().engine());
         Ok(engine)
     }

lib/compiler/src/engine/inner.rs

@@ -1,97 +0,0 @@
-//! Engine trait and associated types.
-
-use crate::engine::tunables::Tunables;
-use crate::UniversalArtifact;
-use memmap2::Mmap;
-use std::path::Path;
-use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
-use std::sync::Arc;
-use wasmer_types::{CompileError, DeserializeError, FunctionType, Target};
-use wasmer_vm::VMSharedSignatureIndex;
-
-/// A unimplemented Wasmer `Engine`.
-///
-/// This trait is used by implementors to implement custom engines
-/// such as: Universal or Native.
-///
-/// The product that an `Engine` produces and consumes is the [`Artifact`].
-pub trait Engine {
-    /// Gets the target
-    fn target(&self) -> &Target;
-
-    /// Register a signature
-    fn register_signature(&self, func_type: &FunctionType) -> VMSharedSignatureIndex;
-
-    /// Lookup a signature
-    fn lookup_signature(&self, sig: VMSharedSignatureIndex) -> Option<FunctionType>;
-
-    /// Validates a WebAssembly module
-    fn validate(&self, binary: &[u8]) -> Result<(), CompileError>;
-
-    /// Compile a WebAssembly binary
-    fn compile(
-        &self,
-        binary: &[u8],
-        tunables: &dyn Tunables,
-    ) -> Result<Arc<UniversalArtifact>, CompileError>;
-
-    /// Deserializes a WebAssembly module
-    ///
-    /// # Safety
-    ///
-    /// The serialized content must represent a serialized WebAssembly module.
-    unsafe fn deserialize(&self, bytes: &[u8]) -> Result<Arc<UniversalArtifact>, DeserializeError>;
-
-    /// Deserializes a WebAssembly module from a path
-    ///
-    /// # Safety
-    ///
-    /// The file's content must represent a serialized WebAssembly module.
-    unsafe fn deserialize_from_file(
-        &self,
-        file_ref: &Path,
-    ) -> Result<Arc<UniversalArtifact>, DeserializeError> {
-        let file = std::fs::File::open(file_ref)?;
-        let mmap = Mmap::map(&file)?;
-        self.deserialize(&mmap)
-    }
-
-    /// A unique identifier for this object.
-    ///
-    /// This exists to allow us to compare two Engines for equality. Otherwise,
-    /// comparing two trait objects unsafely relies on implementation details
-    /// of trait representation.
-    fn id(&self) -> &EngineId;
-
-    /// Clone the engine
-    fn cloned(&self) -> Arc<dyn Engine + Send + Sync>;
-}
-
-#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
-#[repr(transparent)]
-/// A unique identifier for an Engine.
-pub struct EngineId {
-    id: usize,
-}
-
-impl EngineId {
-    /// Format this identifier as a string.
-    pub fn id(&self) -> String {
-        format!("{}", &self.id)
-    }
-}
-
-impl Clone for EngineId {
-    fn clone(&self) -> Self {
-        Self::default()
-    }
-}
-
-impl Default for EngineId {
-    fn default() -> Self {
-        static NEXT_ID: AtomicUsize = AtomicUsize::new(0);
-        Self {
-            id: NEXT_ID.fetch_add(1, SeqCst),
-        }
-    }
-}

lib/compiler/src/engine/mod.rs

@@ -1,7 +1,6 @@
-//! Generic Engine abstraction for Wasmer Engines.
+//! The Wasmer Engine.
 
 mod error;
-mod inner;
 mod resolver;
 mod trap;
 mod tunables;
@@ -10,7 +9,6 @@ mod tunables;
 mod universal;
 
 pub use self::error::{InstantiationError, LinkError};
-pub use self::inner::{Engine, EngineId};
 pub use self::resolver::resolve_imports;
 pub use self::trap::*;
 pub use self::tunables::Tunables;

lib/compiler/src/engine/universal/artifact.rs

@@ -5,13 +5,13 @@ use super::engine::{UniversalEngine, UniversalEngineInner};
 use crate::engine::universal::link::link_module;
 use crate::ArtifactCreate;
 use crate::Features;
+#[cfg(feature = "universal_engine")]
+use crate::ModuleEnvironment;
 use crate::UniversalArtifactBuild;
 use crate::{
     register_frame_info, resolve_imports, FunctionExtent, GlobalFrameInfoRegistration,
     InstantiationError, MetadataHeader, RuntimeError, Tunables,
 };
-#[cfg(feature = "universal_engine")]
-use crate::{Engine, ModuleEnvironment};
 use enumset::EnumSet;
 use std::sync::Arc;
 use std::sync::Mutex;

lib/compiler/src/engine/universal/engine.rs

@@ -4,7 +4,10 @@
 use crate::Compiler;
 use crate::UniversalEngineBuilder;
 use crate::{CodeMemory, UniversalArtifact};
-use crate::{Engine, EngineId, FunctionExtent, Tunables};
+use crate::{FunctionExtent, Tunables};
+use memmap2::Mmap;
+use std::path::Path;
+use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
 use std::sync::{Arc, Mutex};
 use wasmer_types::entity::PrimaryMap;
 use wasmer_types::FunctionBody;
@@ -74,34 +77,32 @@ impl UniversalEngine {
     pub(crate) fn inner_mut(&self) -> std::sync::MutexGuard<'_, UniversalEngineInner> {
         self.inner.lock().unwrap()
     }
-}
 
-impl Engine for UniversalEngine {
+    /// Gets the target
-    /// The target
+    pub fn target(&self) -> &Target {
-    fn target(&self) -> &Target {
         &self.target
     }
 
     /// Register a signature
-    fn register_signature(&self, func_type: &FunctionType) -> VMSharedSignatureIndex {
+    pub fn register_signature(&self, func_type: &FunctionType) -> VMSharedSignatureIndex {
         let compiler = self.inner();
         compiler.signatures().register(func_type)
     }
 
     /// Lookup a signature
-    fn lookup_signature(&self, sig: VMSharedSignatureIndex) -> Option<FunctionType> {
+    pub fn lookup_signature(&self, sig: VMSharedSignatureIndex) -> Option<FunctionType> {
         let compiler = self.inner();
         compiler.signatures().lookup(sig)
     }
 
     /// Validates a WebAssembly module
-    fn validate(&self, binary: &[u8]) -> Result<(), CompileError> {
+    pub fn validate(&self, binary: &[u8]) -> Result<(), CompileError> {
         self.inner().validate(binary)
     }
 
     /// Compile a WebAssembly binary
     #[cfg(feature = "universal_engine")]
-    fn compile(
+    pub fn compile(
         &self,
         binary: &[u8],
         tunables: &dyn Tunables,
@@ -111,7 +112,7 @@ impl Engine for UniversalEngine {
 
     /// Compile a WebAssembly binary
     #[cfg(not(feature = "universal_engine"))]
-    fn compile(
+    pub fn compile(
         &self,
         _binary: &[u8],
         _tunables: &dyn Tunables,
@@ -123,15 +124,42 @@ impl Engine for UniversalEngine {
     }
 
     /// Deserializes a WebAssembly module
-    unsafe fn deserialize(&self, bytes: &[u8]) -> Result<Arc<UniversalArtifact>, DeserializeError> {
+    ///
+    /// # Safety
+    ///
+    /// The serialized content must represent a serialized WebAssembly module.
+    pub unsafe fn deserialize(
+        &self,
+        bytes: &[u8],
+    ) -> Result<Arc<UniversalArtifact>, DeserializeError> {
         Ok(Arc::new(UniversalArtifact::deserialize(self, bytes)?))
     }
 
-    fn id(&self) -> &EngineId {
+    /// Deserializes a WebAssembly module from a path
+    ///
+    /// # Safety
+    ///
+    /// The file's content must represent a serialized WebAssembly module.
+    pub unsafe fn deserialize_from_file(
+        &self,
+        file_ref: &Path,
+    ) -> Result<Arc<UniversalArtifact>, DeserializeError> {
+        let file = std::fs::File::open(file_ref)?;
+        let mmap = Mmap::map(&file)?;
+        self.deserialize(&mmap)
+    }
+
+    /// A unique identifier for this object.
+    ///
+    /// This exists to allow us to compare two Engines for equality. Otherwise,
+    /// comparing two trait objects unsafely relies on implementation details
+    /// of trait representation.
+    pub fn id(&self) -> &EngineId {
         &self.engine_id
     }
 
-    fn cloned(&self) -> Arc<dyn Engine + Send + Sync> {
+    /// Clone the engine
+    pub fn cloned(&self) -> Arc<Self> {
         Arc::new(self.clone())
     }
 }
@@ -285,3 +313,32 @@ impl UniversalEngineInner {
         &self.signatures
     }
 }
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[repr(transparent)]
+/// A unique identifier for an Engine.
+pub struct EngineId {
+    id: usize,
+}
+
+impl EngineId {
+    /// Format this identifier as a string.
+    pub fn id(&self) -> String {
+        format!("{}", &self.id)
+    }
+}
+
+impl Clone for EngineId {
+    fn clone(&self) -> Self {
+        Self::default()
+    }
+}
+
+impl Default for EngineId {
+    fn default() -> Self {
+        static NEXT_ID: AtomicUsize = AtomicUsize::new(0);
+        Self {
+            id: NEXT_ID.fetch_add(1, SeqCst),
+        }
+    }
+}

tests/compilers/config.rs

@@ -1,5 +1,6 @@
 use std::sync::Arc;
-use wasmer::{CompilerConfig, Engine, Features, ModuleMiddleware, Store};
+use wasmer::{CompilerConfig, Features, ModuleMiddleware, Store};
+use wasmer_compiler::UniversalEngine;
 
 #[derive(Clone, Debug, PartialEq)]
 pub enum Compiler {
@@ -49,7 +50,7 @@ impl Config {
         Store::new_with_engine(&*engine)
     }
 
-    pub fn engine(&self, compiler_config: Box<dyn CompilerConfig>) -> Box<dyn Engine> {
+    pub fn engine(&self, compiler_config: Box<dyn CompilerConfig>) -> Box<UniversalEngine> {
         let mut engine = wasmer_compiler::Universal::new(compiler_config);
         if let Some(ref features) = self.features {
             engine = engine.features(features.clone())
@@ -57,7 +58,7 @@ impl Config {
         Box::new(engine.engine())
     }
 
-    pub fn engine_headless(&self) -> Box<dyn Engine> {
+    pub fn engine_headless(&self) -> Box<UniversalEngine> {
         Box::new(wasmer_compiler::Universal::headless().engine())
     }
 

tests/lib/compiler-test-derive/src/ignores.rs

@@ -115,7 +115,7 @@ impl Ignores {
                             arch = Some(alias.to_string());
                         }
                         // Engines
-                        "universal" => {
+                        "universal" | "engine" => {
                             engine = Some(alias.to_string());
                         }
                         // Compilers