Move compilation into Module from Instance. (#822)

* Move compilation into Module from Instance.

* Fix fuzzing

* Use wasmtime::Module in fuzzing crates

Instead of wasmtime_jit.

* Compile eagerly.

* Review fixes.

* Always use the saved name.

* Preserve the former behavior for fuzzing oracle

Cargo.lock

@@ -2166,7 +2166,6 @@ dependencies = [
  "log",
  "wasmtime",
  "wasmtime-fuzzing",
- "wasmtime-jit",
 ]
 
 [[package]]
@@ -2181,8 +2180,6 @@ dependencies = [
  "wasmparser 0.47.0",
  "wasmprinter",
  "wasmtime",
- "wasmtime-environ",
- "wasmtime-jit",
  "wat",
 ]
 

crates/api/src/instance.rs

@@ -20,36 +20,22 @@ impl Resolver for SimpleResolver<'_> {
     }
 }
 
-fn instantiate_in_context(
+fn instantiate(
-    store: &Store,
+    compiled_module: &CompiledModule,
-    data: &[u8],
     imports: &[Extern],
-    module_name: Option<&str>,
+) -> Result<InstanceHandle, Error> {
-) -> Result<InstanceHandle> {
     let mut resolver = SimpleResolver { imports };
-    let mut compiled_module = CompiledModule::new(
+    let instance = compiled_module
-        &mut store.compiler_mut(),
+        .instantiate(&mut resolver)
-        data,
+        .map_err(|e| -> Error {
-        module_name,
+            if let Some(trap) = take_api_trap() {
-        &mut resolver,
+                trap.into()
-        store.global_exports().clone(),
+            } else if let InstantiationError::StartTrap(trap) = e {
-        store.engine().config().debug_info,
+                Trap::from_jit(trap).into()
-    )?;
+            } else {
-
+                e.into()
-    // Register all module signatures
+            }
-    for signature in compiled_module.module().signatures.values() {
+        })?;
-        store.register_wasmtime_signature(signature);
-    }
-
-    let instance = compiled_module.instantiate().map_err(|e| -> Error {
-        if let Some(trap) = take_api_trap() {
-            trap.into()
-        } else if let InstantiationError::StartTrap(trap) = e {
-            Trap::from_jit(trap).into()
-        } else {
-            e.into()
-        }
-    })?;
     Ok(instance)
 }
 
@@ -63,12 +49,8 @@ pub struct Instance {
 impl Instance {
     pub fn new(module: &Module, externs: &[Extern]) -> Result<Instance, Error> {
         let store = module.store();
-        let mut instance_handle = instantiate_in_context(
+        let mut instance_handle =
-            store,
+            instantiate(module.compiled_module().expect("compiled_module"), externs)?;
-            module.binary().expect("binary"),
-            externs,
-            module.name(),
-        )?;
 
         let exports = {
             let mut exports = Vec::with_capacity(module.exports().len());

crates/api/src/module.rs

@@ -9,6 +9,7 @@ use wasmparser::{
     validate, CustomSectionKind, ExternalKind, ImportSectionEntryType, ModuleReader, Name,
     OperatorValidatorConfig, SectionCode, ValidatingParserConfig,
 };
+use wasmtime_jit::CompiledModule;
 
 fn into_memory_type(mt: wasmparser::MemoryType) -> MemoryType {
     assert!(!mt.shared);
@@ -56,12 +57,6 @@ fn into_table_type(tt: wasmparser::TableType) -> TableType {
     TableType::new(ty, limits)
 }
 
-#[derive(Clone)]
-pub(crate) enum ModuleCodeSource {
-    Binary(Box<[u8]>),
-    Unknown,
-}
-
 /// A compiled WebAssembly module, ready to be instantiated.
 ///
 /// A `Module` is a compiled in-memory representation of an input WebAssembly
@@ -84,10 +79,10 @@ pub struct Module {
 
 struct ModuleInner {
     store: Store,
-    source: ModuleCodeSource,
     imports: Box<[ImportType]>,
     exports: Box<[ExportType]>,
     name: Option<String>,
+    compiled: Option<CompiledModule>,
 }
 
 impl Module {
@@ -131,7 +126,7 @@ impl Module {
         // Note that the call to `unsafe` here should be ok because we
         // previously validated the binary, meaning we're guaranteed to pass a
         // valid binary for `store`.
-        unsafe { Module::new_unchecked(store, binary) }
+        unsafe { Module::new_internal(store, binary, None) }
     }
 
     /// Creates a new WebAssembly `Module` from the given in-memory `binary`
@@ -139,9 +134,11 @@ impl Module {
     ///
     /// See [`Module::new`] for other details.
     pub fn new_with_name(store: &Store, binary: &[u8], name: &str) -> Result<Module> {
-        let mut ret = Module::new(store, binary)?;
+        Module::validate(store, binary)?;
-        Rc::get_mut(&mut ret.inner).unwrap().name = Some(name.to_string());
+        // Note that the call to `unsafe` here should be ok because we
-        Ok(ret)
+        // previously validated the binary, meaning we're guaranteed to pass a
+        // valid binary for `store`.
+        unsafe { Module::new_internal(store, binary, Some(name)) }
     }
 
     /// Creates a new WebAssembly `Module` from the given in-memory `binary`
@@ -171,8 +168,20 @@ impl Module {
     /// be somewhat valid for decoding purposes, and the basics of decoding can
     /// still fail.
     pub unsafe fn new_unchecked(store: &Store, binary: &[u8]) -> Result<Module> {
+        Module::new_internal(store, binary, None)
+    }
+
+    /// Creates a new `Module` and compiles it without doing any validation.
+    unsafe fn new_internal(store: &Store, binary: &[u8], name: Option<&str>) -> Result<Module> {
         let mut ret = Module::empty(store);
         ret.read_imports_and_exports(binary)?;
+
+        let inner = Rc::get_mut(&mut ret.inner).unwrap();
+        if let Some(name) = name {
+            // Assign or override the module's name if supplied.
+            inner.name = Some(name.to_string());
+        }
+        inner.compiled = Some(compile(store, binary, inner.name.as_deref())?);
         Ok(ret)
     }
 
@@ -219,19 +228,16 @@ impl Module {
         Module {
             inner: Rc::new(ModuleInner {
                 store: store.clone(),
-                source: ModuleCodeSource::Unknown,
                 imports: Box::new([]),
                 exports: Box::new([]),
                 name: None,
+                compiled: None,
             }),
         }
     }
 
-    pub(crate) fn binary(&self) -> Option<&[u8]> {
+    pub(crate) fn compiled_module(&self) -> Option<&CompiledModule> {
-        match &self.inner.source {
+        self.inner.compiled.as_ref()
-            ModuleCodeSource::Binary(b) => Some(b),
-            _ => None,
-        }
     }
 
     /// Returns identifier/name that this [`Module`] has. This name
@@ -259,7 +265,6 @@ impl Module {
 
     fn read_imports_and_exports(&mut self, binary: &[u8]) -> Result<()> {
         let inner = Rc::get_mut(&mut self.inner).unwrap();
-        inner.source = ModuleCodeSource::Binary(binary.into());
         let mut reader = ModuleReader::new(binary)?;
         let mut imports = Vec::new();
         let mut exports = Vec::new();
@@ -387,3 +392,21 @@ impl Module {
         Ok(())
     }
 }
+
+fn compile(store: &Store, binary: &[u8], module_name: Option<&str>) -> Result<CompiledModule> {
+    let exports = store.global_exports().clone();
+    let compiled_module = CompiledModule::new(
+        &mut store.compiler_mut(),
+        binary,
+        module_name,
+        exports,
+        store.engine().config().debug_info,
+    )?;
+
+    // Register all module signatures
+    for signature in compiled_module.module().signatures.values() {
+        store.register_wasmtime_signature(signature);
+    }
+
+    Ok(compiled_module)
+}

crates/fuzzing/Cargo.toml

@@ -17,8 +17,6 @@ log = "0.4.8"
 wasmparser = "0.47.0"
 wasmprinter = "0.2.0"
 wasmtime = { path = "../api", version = "0.9.0" }
-wasmtime-environ = { path = "../environ", version = "0.9.0" }
-wasmtime-jit = { path = "../jit", version = "0.9.0" }
 
 [dev-dependencies]
 wat = "1.0"

crates/fuzzing/src/oracles.rs

@@ -13,25 +13,15 @@
 pub mod dummy;
 
 use dummy::{dummy_imports, dummy_value};
-use std::cell::RefCell;
 use std::collections::HashMap;
-use std::rc::Rc;
 use wasmtime::*;
-use wasmtime_environ::{isa, settings};
-use wasmtime_jit::{native, CompilationStrategy, CompiledModule, Compiler, NullResolver};
-
-fn host_isa() -> Box<dyn isa::TargetIsa> {
-    let flag_builder = settings::builder();
-    let isa_builder = native::builder();
-    isa_builder.finish(settings::Flags::new(flag_builder))
-}
 
 /// Instantiate the Wasm buffer, and implicitly fail if we have an unexpected
 /// panic or segfault or anything else that can be detected "passively".
 ///
 /// Performs initial validation, and returns early if the Wasm is invalid.
 ///
-/// You can control which compiler is used via passing a `CompilationStrategy`.
+/// You can control which compiler is used via passing a `Strategy`.
 pub fn instantiate(wasm: &[u8], strategy: Strategy) {
     if wasmparser::validate(wasm, None).is_err() {
         return;
@@ -68,24 +58,13 @@ pub fn instantiate(wasm: &[u8], strategy: Strategy) {
 ///
 /// Performs initial validation, and returns early if the Wasm is invalid.
 ///
-/// You can control which compiler is used via passing a `CompilationStrategy`.
+/// You can control which compiler is used via passing a `Strategy`.
-pub fn compile(wasm: &[u8], compilation_strategy: CompilationStrategy) {
+pub fn compile(wasm: &[u8], strategy: Strategy) {
-    if wasmparser::validate(wasm, None).is_err() {
+    let mut config = Config::new();
-        return;
+    config.strategy(strategy).unwrap();
-    }
+    let engine = Engine::new(&config);
-
+    let store = Store::new(&engine);
-    let isa = host_isa();
+    let _ = Module::new(&store, wasm);
-    let mut compiler = Compiler::new(isa, compilation_strategy);
-    let mut resolver = NullResolver {};
-    let global_exports = Rc::new(RefCell::new(HashMap::new()));
-    let _ = CompiledModule::new(
-        &mut compiler,
-        wasm,
-        None,
-        &mut resolver,
-        global_exports,
-        false,
-    );
 }
 
 /// Invoke the given API calls.

crates/jit/src/context.rs

@@ -156,7 +156,6 @@ impl Context {
             &mut *self.compiler,
             data,
             None,
-            &mut self.namespace,
             Rc::clone(&self.global_exports),
             debug_info,
         )

crates/jit/src/imports.rs

@@ -0,0 +1,289 @@
+//! Module imports resolving logic.
+
+use crate::resolver::Resolver;
+use more_asserts::assert_ge;
+use std::collections::HashSet;
+use wasmtime_environ::entity::PrimaryMap;
+use wasmtime_environ::wasm::{Global, GlobalInit, Memory, Table, TableElementType};
+use wasmtime_environ::{MemoryPlan, MemoryStyle, Module, TablePlan};
+use wasmtime_runtime::{
+    Export, Imports, InstanceHandle, LinkError, VMFunctionImport, VMGlobalImport, VMMemoryImport,
+    VMTableImport,
+};
+
+/// This function allows to match all imports of a `Module` with concrete definitions provided by
+/// a `Resolver`.
+///
+/// If all imports are satisfied returns an `Imports` instance required for a module instantiation.
+pub fn resolve_imports(module: &Module, resolver: &mut dyn Resolver) -> Result<Imports, LinkError> {
+    let mut dependencies = HashSet::new();
+
+    let mut function_imports = PrimaryMap::with_capacity(module.imported_funcs.len());
+    for (index, (module_name, field, import_idx)) in module.imported_funcs.iter() {
+        match resolver.resolve(*import_idx, module_name, field) {
+            Some(export_value) => match export_value {
+                Export::Function {
+                    address,
+                    signature,
+                    vmctx,
+                } => {
+                    let import_signature = &module.signatures[module.functions[index]];
+                    if signature != *import_signature {
+                        // TODO: If the difference is in the calling convention,
+                        // we could emit a wrapper function to fix it up.
+                        return Err(LinkError(format!(
+                            "{}/{}: incompatible import type: exported function with signature {} \
+                             incompatible with function import with signature {}",
+                            module_name, field, signature, import_signature
+                        )));
+                    }
+                    dependencies.insert(unsafe { InstanceHandle::from_vmctx(vmctx) });
+                    function_imports.push(VMFunctionImport {
+                        body: address,
+                        vmctx,
+                    });
+                }
+                Export::Table { .. } | Export::Memory { .. } | Export::Global { .. } => {
+                    return Err(LinkError(format!(
+                        "{}/{}: incompatible import type: export incompatible with function import",
+                        module_name, field
+                    )));
+                }
+            },
+            None => {
+                return Err(LinkError(format!(
+                    "{}/{}: unknown import function: function not provided",
+                    module_name, field
+                )));
+            }
+        }
+    }
+
+    let mut table_imports = PrimaryMap::with_capacity(module.imported_tables.len());
+    for (index, (module_name, field, import_idx)) in module.imported_tables.iter() {
+        match resolver.resolve(*import_idx, module_name, field) {
+            Some(export_value) => match export_value {
+                Export::Table {
+                    definition,
+                    vmctx,
+                    table,
+                } => {
+                    let import_table = &module.table_plans[index];
+                    if !is_table_compatible(&table, import_table) {
+                        return Err(LinkError(format!(
+                            "{}/{}: incompatible import type: exported table incompatible with \
+                             table import",
+                            module_name, field,
+                        )));
+                    }
+                    dependencies.insert(unsafe { InstanceHandle::from_vmctx(vmctx) });
+                    table_imports.push(VMTableImport {
+                        from: definition,
+                        vmctx,
+                    });
+                }
+                Export::Global { .. } | Export::Memory { .. } | Export::Function { .. } => {
+                    return Err(LinkError(format!(
+                        "{}/{}: incompatible import type: export incompatible with table import",
+                        module_name, field
+                    )));
+                }
+            },
+            None => {
+                return Err(LinkError(format!(
+                    "unknown import: no provided import table for {}/{}",
+                    module_name, field
+                )));
+            }
+        }
+    }
+
+    let mut memory_imports = PrimaryMap::with_capacity(module.imported_memories.len());
+    for (index, (module_name, field, import_idx)) in module.imported_memories.iter() {
+        match resolver.resolve(*import_idx, module_name, field) {
+            Some(export_value) => match export_value {
+                Export::Memory {
+                    definition,
+                    vmctx,
+                    memory,
+                } => {
+                    let import_memory = &module.memory_plans[index];
+                    if !is_memory_compatible(&memory, import_memory) {
+                        return Err(LinkError(format!(
+                            "{}/{}: incompatible import type: exported memory incompatible with \
+                             memory import",
+                            module_name, field
+                        )));
+                    }
+
+                    // Sanity-check: Ensure that the imported memory has at least
+                    // guard-page protections the importing module expects it to have.
+                    if let (
+                        MemoryStyle::Static { bound },
+                        MemoryStyle::Static {
+                            bound: import_bound,
+                        },
+                    ) = (memory.style, &import_memory.style)
+                    {
+                        assert_ge!(bound, *import_bound);
+                    }
+                    assert_ge!(memory.offset_guard_size, import_memory.offset_guard_size);
+
+                    dependencies.insert(unsafe { InstanceHandle::from_vmctx(vmctx) });
+                    memory_imports.push(VMMemoryImport {
+                        from: definition,
+                        vmctx,
+                    });
+                }
+                Export::Table { .. } | Export::Global { .. } | Export::Function { .. } => {
+                    return Err(LinkError(format!(
+                        "{}/{}: incompatible import type: export incompatible with memory import",
+                        module_name, field
+                    )));
+                }
+            },
+            None => {
+                return Err(LinkError(format!(
+                    "unknown import: no provided import memory for {}/{}",
+                    module_name, field
+                )));
+            }
+        }
+    }
+
+    let mut global_imports = PrimaryMap::with_capacity(module.imported_globals.len());
+    for (index, (module_name, field, import_idx)) in module.imported_globals.iter() {
+        match resolver.resolve(*import_idx, module_name, field) {
+            Some(export_value) => match export_value {
+                Export::Table { .. } | Export::Memory { .. } | Export::Function { .. } => {
+                    return Err(LinkError(format!(
+                        "{}/{}: incompatible import type: exported global incompatible with \
+                         global import",
+                        module_name, field
+                    )));
+                }
+                Export::Global {
+                    definition,
+                    vmctx,
+                    global,
+                } => {
+                    let imported_global = module.globals[index];
+                    if !is_global_compatible(&global, &imported_global) {
+                        return Err(LinkError(format!(
+                            "{}/{}: incompatible import type: exported global incompatible with \
+                             global import",
+                            module_name, field
+                        )));
+                    }
+                    dependencies.insert(unsafe { InstanceHandle::from_vmctx(vmctx) });
+                    global_imports.push(VMGlobalImport { from: definition });
+                }
+            },
+            None => {
+                return Err(LinkError(format!(
+                    "unknown import: no provided import global for {}/{}",
+                    module_name, field
+                )));
+            }
+        }
+    }
+
+    Ok(Imports::new(
+        dependencies,
+        function_imports,
+        table_imports,
+        memory_imports,
+        global_imports,
+    ))
+}
+
+fn is_global_compatible(exported: &Global, imported: &Global) -> bool {
+    match imported.initializer {
+        GlobalInit::Import => (),
+        _ => panic!("imported Global should have an Imported initializer"),
+    }
+
+    let Global {
+        ty: exported_ty,
+        mutability: exported_mutability,
+        initializer: _exported_initializer,
+    } = exported;
+    let Global {
+        ty: imported_ty,
+        mutability: imported_mutability,
+        initializer: _imported_initializer,
+    } = imported;
+    exported_ty == imported_ty && imported_mutability == exported_mutability
+}
+
+fn is_table_element_type_compatible(
+    exported_type: TableElementType,
+    imported_type: TableElementType,
+) -> bool {
+    match exported_type {
+        TableElementType::Func => match imported_type {
+            TableElementType::Func => true,
+            _ => false,
+        },
+        TableElementType::Val(exported_val_ty) => match imported_type {
+            TableElementType::Val(imported_val_ty) => exported_val_ty == imported_val_ty,
+            _ => false,
+        },
+    }
+}
+
+fn is_table_compatible(exported: &TablePlan, imported: &TablePlan) -> bool {
+    let TablePlan {
+        table:
+            Table {
+                ty: exported_ty,
+                minimum: exported_minimum,
+                maximum: exported_maximum,
+            },
+        style: _exported_style,
+    } = exported;
+    let TablePlan {
+        table:
+            Table {
+                ty: imported_ty,
+                minimum: imported_minimum,
+                maximum: imported_maximum,
+            },
+        style: _imported_style,
+    } = imported;
+
+    is_table_element_type_compatible(*exported_ty, *imported_ty)
+        && imported_minimum <= exported_minimum
+        && (imported_maximum.is_none()
+            || (!exported_maximum.is_none()
+                && imported_maximum.unwrap() >= exported_maximum.unwrap()))
+}
+
+fn is_memory_compatible(exported: &MemoryPlan, imported: &MemoryPlan) -> bool {
+    let MemoryPlan {
+        memory:
+            Memory {
+                minimum: exported_minimum,
+                maximum: exported_maximum,
+                shared: exported_shared,
+            },
+        style: _exported_style,
+        offset_guard_size: _exported_offset_guard_size,
+    } = exported;
+    let MemoryPlan {
+        memory:
+            Memory {
+                minimum: imported_minimum,
+                maximum: imported_maximum,
+                shared: imported_shared,
+            },
+        style: _imported_style,
+        offset_guard_size: _imported_offset_guard_size,
+    } = imported;
+
+    imported_minimum <= exported_minimum
+        && (imported_maximum.is_none()
+            || (!exported_maximum.is_none()
+                && imported_maximum.unwrap() >= exported_maximum.unwrap()))
+        && exported_shared == imported_shared
+}

crates/jit/src/instantiate.rs

@@ -4,6 +4,7 @@
 //! steps.
 
 use crate::compiler::Compiler;
+use crate::imports::resolve_imports;
 use crate::link::link_module;
 use crate::resolver::Resolver;
 use std::cell::RefCell;
@@ -19,7 +20,7 @@ use wasmtime_environ::{
     ModuleSyncString,
 };
 use wasmtime_runtime::{
-    Export, GdbJitImageRegistration, Imports, InstanceHandle, InstantiationError, VMFunctionBody,
+    Export, GdbJitImageRegistration, InstanceHandle, InstantiationError, VMFunctionBody,
     VMSharedSignatureIndex,
 };
 
@@ -50,7 +51,6 @@ pub enum SetupError {
 struct RawCompiledModule<'data> {
     module: Module,
     finished_functions: BoxedSlice<DefinedFuncIndex, *const VMFunctionBody>,
-    imports: Imports,
     data_initializers: Box<[DataInitializer<'data>]>,
     signatures: BoxedSlice<SignatureIndex, VMSharedSignatureIndex>,
     dbg_jit_registration: Option<GdbJitImageRegistration>,
@@ -62,7 +62,6 @@ impl<'data> RawCompiledModule<'data> {
         compiler: &mut Compiler,
         data: &'data [u8],
         module_name: Option<&str>,
-        resolver: &mut dyn Resolver,
         debug_info: bool,
     ) -> Result<Self, SetupError> {
         let environ = ModuleEnvironment::new(compiler.frontend_config(), compiler.tunables());
@@ -86,14 +85,12 @@ impl<'data> RawCompiledModule<'data> {
             debug_data,
         )?;
 
-        let imports = link_module(
+        link_module(
             &translation.module,
             &allocated_functions,
             &jt_offsets,
             relocations,
-            resolver,
+        );
-        )
-        .map_err(|err| SetupError::Instantiate(InstantiationError::Link(err)))?;
 
         // Gather up the pointers to the compiled functions.
         let finished_functions: BoxedSlice<DefinedFuncIndex, *const VMFunctionBody> =
@@ -132,7 +129,6 @@ impl<'data> RawCompiledModule<'data> {
         Ok(Self {
             module: translation.module,
             finished_functions,
-            imports,
             data_initializers: translation.data_initializers.into_boxed_slice(),
             signatures: signatures.into_boxed_slice(),
             dbg_jit_registration,
@@ -144,7 +140,6 @@ impl<'data> RawCompiledModule<'data> {
 pub struct CompiledModule {
     module: Rc<Module>,
     finished_functions: BoxedSlice<DefinedFuncIndex, *const VMFunctionBody>,
-    imports: Imports,
     data_initializers: Box<[OwnedDataInitializer]>,
     signatures: BoxedSlice<SignatureIndex, VMSharedSignatureIndex>,
     global_exports: Rc<RefCell<HashMap<String, Option<Export>>>>,
@@ -157,18 +152,15 @@ impl CompiledModule {
         compiler: &mut Compiler,
         data: &'data [u8],
         module_name: Option<&str>,
-        resolver: &mut dyn Resolver,
         global_exports: Rc<RefCell<HashMap<String, Option<Export>>>>,
         debug_info: bool,
     ) -> Result<Self, SetupError> {
-        let raw =
+        let raw = RawCompiledModule::<'data>::new(compiler, data, module_name, debug_info)?;
-            RawCompiledModule::<'data>::new(compiler, data, module_name, resolver, debug_info)?;
 
         Ok(Self::from_parts(
             raw.module,
             global_exports,
             raw.finished_functions,
-            raw.imports,
             raw.data_initializers
                 .iter()
                 .map(OwnedDataInitializer::new)
@@ -184,7 +176,6 @@ impl CompiledModule {
         module: Module,
         global_exports: Rc<RefCell<HashMap<String, Option<Export>>>>,
         finished_functions: BoxedSlice<DefinedFuncIndex, *const VMFunctionBody>,
-        imports: Imports,
         data_initializers: Box<[OwnedDataInitializer]>,
         signatures: BoxedSlice<SignatureIndex, VMSharedSignatureIndex>,
         dbg_jit_registration: Option<GdbJitImageRegistration>,
@@ -193,7 +184,6 @@ impl CompiledModule {
             module: Rc::new(module),
             global_exports: Rc::clone(&global_exports),
             finished_functions,
-            imports,
             data_initializers,
             signatures,
             dbg_jit_registration: dbg_jit_registration.map(Rc::new),
@@ -205,7 +195,10 @@ impl CompiledModule {
     /// Note that if only one instance of this module is needed, it may be more
     /// efficient to call the top-level `instantiate`, since that avoids copying
     /// the data initializers.
-    pub fn instantiate(&mut self) -> Result<InstanceHandle, InstantiationError> {
+    pub fn instantiate(
+        &self,
+        resolver: &mut dyn Resolver,
+    ) -> Result<InstanceHandle, InstantiationError> {
         let data_initializers = self
             .data_initializers
             .iter()
@@ -214,11 +207,12 @@ impl CompiledModule {
                 data: &*init.data,
             })
             .collect::<Vec<_>>();
+        let imports = resolve_imports(&self.module, resolver)?;
         InstanceHandle::new(
             Rc::clone(&self.module),
             Rc::clone(&self.global_exports),
             self.finished_functions.clone(),
-            self.imports.clone(),
+            imports,
             &data_initializers,
             self.signatures.clone(),
             self.dbg_jit_registration.as_ref().map(|r| Rc::clone(&r)),
@@ -269,13 +263,14 @@ pub fn instantiate(
     global_exports: Rc<RefCell<HashMap<String, Option<Export>>>>,
     debug_info: bool,
 ) -> Result<InstanceHandle, SetupError> {
-    let raw = RawCompiledModule::new(compiler, data, module_name, resolver, debug_info)?;
+    let raw = RawCompiledModule::new(compiler, data, module_name, debug_info)?;
-
+    let imports = resolve_imports(&raw.module, resolver)
+        .map_err(|err| SetupError::Instantiate(InstantiationError::Link(err)))?;
     InstanceHandle::new(
         Rc::new(raw.module),
         global_exports,
         raw.finished_functions,
-        raw.imports,
+        imports,
         &*raw.data_initializers,
         raw.signatures,
         raw.dbg_jit_registration.map(Rc::new),

crates/jit/src/lib.rs

@@ -26,6 +26,7 @@ mod code_memory;
 mod compiler;
 mod context;
 mod function_table;
+mod imports;
 mod instantiate;
 mod link;
 mod namespace;

crates/jit/src/link.rs

@@ -1,313 +1,22 @@
 //! Linking for JIT-compiled code.
 
-use crate::resolver::Resolver;
 use cranelift_codegen::binemit::Reloc;
 use cranelift_codegen::ir::JumpTableOffsets;
-use more_asserts::assert_ge;
-use std::collections::HashSet;
 use std::ptr::write_unaligned;
 use wasmtime_environ::entity::PrimaryMap;
-use wasmtime_environ::wasm::{
+use wasmtime_environ::wasm::DefinedFuncIndex;
-    DefinedFuncIndex, Global, GlobalInit, Memory, Table, TableElementType,
+use wasmtime_environ::{Module, RelocationTarget, Relocations};
-};
-use wasmtime_environ::{
-    MemoryPlan, MemoryStyle, Module, Relocation, RelocationTarget, Relocations, TablePlan,
-};
 use wasmtime_runtime::libcalls;
-use wasmtime_runtime::{
+use wasmtime_runtime::VMFunctionBody;
-    Export, Imports, InstanceHandle, LinkError, VMFunctionBody, VMFunctionImport, VMGlobalImport,
-    VMMemoryImport, VMTableImport,
-};
 
 /// Links a module that has been compiled with `compiled_module` in `wasmtime-environ`.
+///
+/// Performs all required relocations inside the function code, provided the necessary metadata.
 pub fn link_module(
     module: &Module,
     allocated_functions: &PrimaryMap<DefinedFuncIndex, *mut [VMFunctionBody]>,
     jt_offsets: &PrimaryMap<DefinedFuncIndex, JumpTableOffsets>,
     relocations: Relocations,
-    resolver: &mut dyn Resolver,
-) -> Result<Imports, LinkError> {
-    let mut dependencies = HashSet::new();
-
-    let mut function_imports = PrimaryMap::with_capacity(module.imported_funcs.len());
-    for (index, (module_name, field, import_idx)) in module.imported_funcs.iter() {
-        match resolver.resolve(*import_idx, module_name, field) {
-            Some(export_value) => match export_value {
-                Export::Function {
-                    address,
-                    signature,
-                    vmctx,
-                } => {
-                    let import_signature = &module.signatures[module.functions[index]];
-                    if signature != *import_signature {
-                        // TODO: If the difference is in the calling convention,
-                        // we could emit a wrapper function to fix it up.
-                        return Err(LinkError(format!(
-                            "{}/{}: incompatible import type: exported function with signature {} \
-                             incompatible with function import with signature {}",
-                            module_name, field, signature, import_signature
-                        )));
-                    }
-                    dependencies.insert(unsafe { InstanceHandle::from_vmctx(vmctx) });
-                    function_imports.push(VMFunctionImport {
-                        body: address,
-                        vmctx,
-                    });
-                }
-                Export::Table { .. } | Export::Memory { .. } | Export::Global { .. } => {
-                    return Err(LinkError(format!(
-                        "{}/{}: incompatible import type: export incompatible with function import",
-                        module_name, field
-                    )));
-                }
-            },
-            None => {
-                return Err(LinkError(format!(
-                    "{}/{}: unknown import function: function not provided",
-                    module_name, field
-                )));
-            }
-        }
-    }
-
-    let mut table_imports = PrimaryMap::with_capacity(module.imported_tables.len());
-    for (index, (module_name, field, import_idx)) in module.imported_tables.iter() {
-        match resolver.resolve(*import_idx, module_name, field) {
-            Some(export_value) => match export_value {
-                Export::Table {
-                    definition,
-                    vmctx,
-                    table,
-                } => {
-                    let import_table = &module.table_plans[index];
-                    if !is_table_compatible(&table, import_table) {
-                        return Err(LinkError(format!(
-                            "{}/{}: incompatible import type: exported table incompatible with \
-                             table import",
-                            module_name, field,
-                        )));
-                    }
-                    dependencies.insert(unsafe { InstanceHandle::from_vmctx(vmctx) });
-                    table_imports.push(VMTableImport {
-                        from: definition,
-                        vmctx,
-                    });
-                }
-                Export::Global { .. } | Export::Memory { .. } | Export::Function { .. } => {
-                    return Err(LinkError(format!(
-                        "{}/{}: incompatible import type: export incompatible with table import",
-                        module_name, field
-                    )));
-                }
-            },
-            None => {
-                return Err(LinkError(format!(
-                    "unknown import: no provided import table for {}/{}",
-                    module_name, field
-                )));
-            }
-        }
-    }
-
-    let mut memory_imports = PrimaryMap::with_capacity(module.imported_memories.len());
-    for (index, (module_name, field, import_idx)) in module.imported_memories.iter() {
-        match resolver.resolve(*import_idx, module_name, field) {
-            Some(export_value) => match export_value {
-                Export::Memory {
-                    definition,
-                    vmctx,
-                    memory,
-                } => {
-                    let import_memory = &module.memory_plans[index];
-                    if !is_memory_compatible(&memory, import_memory) {
-                        return Err(LinkError(format!(
-                            "{}/{}: incompatible import type: exported memory incompatible with \
-                             memory import",
-                            module_name, field
-                        )));
-                    }
-
-                    // Sanity-check: Ensure that the imported memory has at least
-                    // guard-page protections the importing module expects it to have.
-                    if let (
-                        MemoryStyle::Static { bound },
-                        MemoryStyle::Static {
-                            bound: import_bound,
-                        },
-                    ) = (memory.style, &import_memory.style)
-                    {
-                        assert_ge!(bound, *import_bound);
-                    }
-                    assert_ge!(memory.offset_guard_size, import_memory.offset_guard_size);
-
-                    dependencies.insert(unsafe { InstanceHandle::from_vmctx(vmctx) });
-                    memory_imports.push(VMMemoryImport {
-                        from: definition,
-                        vmctx,
-                    });
-                }
-                Export::Table { .. } | Export::Global { .. } | Export::Function { .. } => {
-                    return Err(LinkError(format!(
-                        "{}/{}: incompatible import type: export incompatible with memory import",
-                        module_name, field
-                    )));
-                }
-            },
-            None => {
-                return Err(LinkError(format!(
-                    "unknown import: no provided import memory for {}/{}",
-                    module_name, field
-                )));
-            }
-        }
-    }
-
-    let mut global_imports = PrimaryMap::with_capacity(module.imported_globals.len());
-    for (index, (module_name, field, import_idx)) in module.imported_globals.iter() {
-        match resolver.resolve(*import_idx, module_name, field) {
-            Some(export_value) => match export_value {
-                Export::Table { .. } | Export::Memory { .. } | Export::Function { .. } => {
-                    return Err(LinkError(format!(
-                        "{}/{}: incompatible import type: exported global incompatible with \
-                         global import",
-                        module_name, field
-                    )));
-                }
-                Export::Global {
-                    definition,
-                    vmctx,
-                    global,
-                } => {
-                    let imported_global = module.globals[index];
-                    if !is_global_compatible(&global, &imported_global) {
-                        return Err(LinkError(format!(
-                            "{}/{}: incompatible import type: exported global incompatible with \
-                             global import",
-                            module_name, field
-                        )));
-                    }
-                    dependencies.insert(unsafe { InstanceHandle::from_vmctx(vmctx) });
-                    global_imports.push(VMGlobalImport { from: definition });
-                }
-            },
-            None => {
-                return Err(LinkError(format!(
-                    "unknown import: no provided import global for {}/{}",
-                    module_name, field
-                )));
-            }
-        }
-    }
-
-    // Apply relocations, now that we have virtual addresses for everything.
-    relocate(allocated_functions, jt_offsets, relocations, module);
-
-    Ok(Imports::new(
-        dependencies,
-        function_imports,
-        table_imports,
-        memory_imports,
-        global_imports,
-    ))
-}
-
-fn is_global_compatible(exported: &Global, imported: &Global) -> bool {
-    match imported.initializer {
-        GlobalInit::Import => (),
-        _ => panic!("imported Global should have an Imported initializer"),
-    }
-
-    let Global {
-        ty: exported_ty,
-        mutability: exported_mutability,
-        initializer: _exported_initializer,
-    } = exported;
-    let Global {
-        ty: imported_ty,
-        mutability: imported_mutability,
-        initializer: _imported_initializer,
-    } = imported;
-    exported_ty == imported_ty && imported_mutability == exported_mutability
-}
-
-fn is_table_element_type_compatible(
-    exported_type: TableElementType,
-    imported_type: TableElementType,
-) -> bool {
-    match exported_type {
-        TableElementType::Func => match imported_type {
-            TableElementType::Func => true,
-            _ => false,
-        },
-        TableElementType::Val(exported_val_ty) => match imported_type {
-            TableElementType::Val(imported_val_ty) => exported_val_ty == imported_val_ty,
-            _ => false,
-        },
-    }
-}
-
-fn is_table_compatible(exported: &TablePlan, imported: &TablePlan) -> bool {
-    let TablePlan {
-        table:
-            Table {
-                ty: exported_ty,
-                minimum: exported_minimum,
-                maximum: exported_maximum,
-            },
-        style: _exported_style,
-    } = exported;
-    let TablePlan {
-        table:
-            Table {
-                ty: imported_ty,
-                minimum: imported_minimum,
-                maximum: imported_maximum,
-            },
-        style: _imported_style,
-    } = imported;
-
-    is_table_element_type_compatible(*exported_ty, *imported_ty)
-        && imported_minimum <= exported_minimum
-        && (imported_maximum.is_none()
-            || (!exported_maximum.is_none()
-                && imported_maximum.unwrap() >= exported_maximum.unwrap()))
-}
-
-fn is_memory_compatible(exported: &MemoryPlan, imported: &MemoryPlan) -> bool {
-    let MemoryPlan {
-        memory:
-            Memory {
-                minimum: exported_minimum,
-                maximum: exported_maximum,
-                shared: exported_shared,
-            },
-        style: _exported_style,
-        offset_guard_size: _exported_offset_guard_size,
-    } = exported;
-    let MemoryPlan {
-        memory:
-            Memory {
-                minimum: imported_minimum,
-                maximum: imported_maximum,
-                shared: imported_shared,
-            },
-        style: _imported_style,
-        offset_guard_size: _imported_offset_guard_size,
-    } = imported;
-
-    imported_minimum <= exported_minimum
-        && (imported_maximum.is_none()
-            || (!exported_maximum.is_none()
-                && imported_maximum.unwrap() >= exported_maximum.unwrap()))
-        && exported_shared == imported_shared
-}
-
-/// Performs the relocations inside the function bytecode, provided the necessary metadata.
-fn relocate(
-    allocated_functions: &PrimaryMap<DefinedFuncIndex, *mut [VMFunctionBody]>,
-    jt_offsets: &PrimaryMap<DefinedFuncIndex, JumpTableOffsets>,
-    relocations: PrimaryMap<DefinedFuncIndex, Vec<Relocation>>,
-    module: &Module,
 ) {
     for (i, function_relocs) in relocations.into_iter() {
         for r in function_relocs {

fuzz/Cargo.toml

@@ -13,7 +13,6 @@ arbitrary = "0.2.0"
 env_logger = "0.7.1"
 log = "0.4.8"
 wasmtime-fuzzing = { path = "../crates/fuzzing", features = ["env_logger"] }
-wasmtime-jit = { path = "../crates/jit" }
 wasmtime = { path = "../crates/api" }
 libfuzzer-sys = "0.2.0"
 

fuzz/fuzz_targets/compile.rs

@@ -1,20 +1,14 @@
 #![no_main]
 
 use libfuzzer_sys::fuzz_target;
+use wasmtime::Strategy;
 use wasmtime_fuzzing::{oracles, with_log_wasm_test_case};
-use wasmtime_jit::CompilationStrategy;
 
 fuzz_target!(|data: &[u8]| {
-    with_log_wasm_test_case!(data, |data| oracles::compile(
+    with_log_wasm_test_case!(data, |data| oracles::compile(data, Strategy::Cranelift));
-        data,
-        CompilationStrategy::Cranelift
-    ));
 });
 
 #[cfg(feature = "lightbeam")]
 fuzz_target!(|data: &[u8]| {
-    with_log_wasm_test_case!(data, |data| oracles::compile(
+    with_log_wasm_test_case!(data, |data| oracles::compile(data, Strategy::Lightbeam));
-        data,
-        CompilationStrategy::Lightbeam
-    ));
 });