Split codegen into multiple modules

lib/clif-backend/src/codegen.rs

@@ -25,10 +25,11 @@ use wasmer_runtime::{
     types::{
         ElementType as WasmerElementType, FuncIndex as WasmerFuncIndex, FuncSig as WasmerSignature,
         Global as WasmerGlobal, GlobalDesc as WasmerGlobalDesc, GlobalIndex as WasmerGlobalIndex,
-        GlobalInit as WasmerGlobalInit, Initializer as WasmerInitializer, Map,
+        GlobalInit as WasmerGlobalInit, Initializer as WasmerInitializer,
         Memory as WasmerMemory, MemoryIndex as WasmerMemoryIndex, SigIndex as WasmerSignatureIndex,
-        Table as WasmerTable, TableIndex as WasmerTableIndex, Type as WasmerType, TypedIndex,
+        Table as WasmerTable, TableIndex as WasmerTableIndex, Type as WasmerType,
     },
+    structures::{TypedIndex, Map},
     vm::{self, Ctx as WasmerVMContext},
 };
 
@@ -94,7 +95,7 @@ pub mod converter {
             imported_globals,
             exports,
             data_initializers,
-            table_initializers,
+            elem_initializers,
             start_func,
             sig_registry,
             ..
@@ -112,7 +113,7 @@ pub mod converter {
             imported_globals,
             exports,
             data_initializers,
-            table_initializers,
+            elem_initializers,
             start_func,
             func_assoc,
             sig_registry,
@@ -255,7 +256,7 @@ pub struct CraneliftModule {
     pub data_initializers: Vec<DataInitializer>,
 
     // Function indices to add to table.
-    pub table_initializers: Vec<TableInitializer>,
+    pub elem_initializers: Vec<TableInitializer>,
 
     // The start function index.
     pub start_func: Option<WasmerFuncIndex>,
@@ -289,7 +290,7 @@ impl CraneliftModule {
             imported_globals: Map::new(),
             exports: HashMap::new(),
             data_initializers: Vec::new(),
-            table_initializers: Vec::new(),
+            elem_initializers: Vec::new(),
             start_func: None,
             sig_registry: SigRegistry::new(),
         };
@@ -922,7 +923,7 @@ impl<'data> ModuleEnvironment<'data> for CraneliftModule {
         };
 
         // Add table initializer to list of table initializers
-        self.table_initializers.push(TableInitializer {
+        self.elem_initializers.push(TableInitializer {
             table_index: WasmerTableIndex::new(table_index.index()),
             base,
             elements: elements

lib/clif-backend/src/func_env.rs

@@ -0,0 +1,607 @@
+use crate::{module::Converter, module_env::ModuleEnv};
+use cranelift_codegen::{
+    cursor::FuncCursor,
+    ir::{self, InstBuilder},
+    isa,
+};
+use cranelift_entity::EntityRef;
+use cranelift_wasm::{self, FuncEnvironment, ModuleEnvironment};
+use wasmer_runtime::{
+    memory::LinearMemory,
+    structures::TypedIndex,
+    types::{FuncIndex, GlobalIndex, LocalOrImport, MemoryIndex, TableIndex},
+    vm,
+};
+
+pub struct FuncEnv<'env, 'module, 'isa> {
+    env: &'env ModuleEnv<'module, 'isa>,
+}
+
+impl<'env, 'module, 'isa> FuncEnv<'env, 'module, 'isa> {
+    pub fn new(env: &'env ModuleEnv<'module, 'isa>) -> Self {
+        Self { env }
+    }
+
+    /// Creates a signature with VMContext as the last param
+    pub fn generate_signature(&self, sig_index: cranelift_wasm::SignatureIndex) -> ir::Signature {
+        // Get signature
+        let mut signature = self.env.signatures[Converter(sig_index).into()].clone();
+
+        // Add the vmctx parameter type to it
+        signature.params.push(ir::AbiParam::special(
+            self.pointer_type(),
+            ir::ArgumentPurpose::VMContext,
+        ));
+
+        // Return signature
+        signature
+    }
+}
+
+impl<'env, 'module, 'isa> FuncEnvironment for FuncEnv<'env, 'module, 'isa> {
+    /// Gets configuration information needed for compiling functions
+    fn target_config(&self) -> isa::TargetFrontendConfig {
+        self.env.target_config()
+    }
+
+    /// Gets native pointers types.
+    ///
+    /// `I64` on 64-bit arch; `I32` on 32-bit arch.
+    fn pointer_type(&self) -> ir::Type {
+        ir::Type::int(u16::from(self.target_config().pointer_bits())).unwrap()
+    }
+
+    /// Gets the size of a native pointer in bytes.
+    fn pointer_bytes(&self) -> u8 {
+        self.target_config().pointer_bytes()
+    }
+
+    /// Sets up the necessary preamble definitions in `func` to access the global identified
+    /// by `index`.
+    ///
+    /// The index space covers both imported and locally declared globals.
+    fn make_global(
+        &mut self,
+        func: &mut ir::Function,
+        clif_global_index: cranelift_wasm::GlobalIndex,
+    ) -> cranelift_wasm::GlobalVariable {
+        let global_index: GlobalIndex = Converter(clif_global_index).into();
+
+        // Create VMContext value.
+        let vmctx = func.create_global_value(ir::GlobalValueData::VMContext);
+        let ptr_type = self.pointer_type();
+
+        match global_index.local_or_import(self.env.module) {
+            LocalOrImport::Local(local_global_index) => {
+                let globals_base_addr = func.create_global_value(ir::GlobalValueData::Load {
+                    base: vmctx,
+                    offset: (vm::Ctx::offset_globals() as i32).into(),
+                    global_type: self.pointer_type(),
+                    readonly: true,
+                });
+
+                let offset = local_global_index.index() * vm::LocalGlobal::size() as usize;
+
+                let local_global_addr = func.create_global_value(ir::GlobalValueData::IAddImm {
+                    base: globals_base_addr,
+                    offset: (offset as i64).into(),
+                    global_type: ptr_type,
+                });
+
+                // Create global variable based on the data above.
+                cranelift_wasm::GlobalVariable::Memory {
+                    gv: local_global_addr,
+                    offset: (vm::LocalGlobal::offset_data() as i32).into(),
+                    ty: self.env.get_global(clif_global_index).ty,
+                }
+            }
+            LocalOrImport::Import(imported_global_index) => {
+                let imported_globals_base_addr =
+                    func.create_global_value(ir::GlobalValueData::Load {
+                        base: vmctx,
+                        offset: (vm::Ctx::offset_imported_globals() as i32).into(),
+                        global_type: ptr_type,
+                        readonly: true,
+                    });
+
+                let offset = imported_global_index.index() * vm::ImportedGlobal::size() as usize;
+
+                let imported_global_addr = func.create_global_value(ir::GlobalValueData::IAddImm {
+                    base: imported_globals_base_addr,
+                    offset: (offset as i64).into(),
+                    global_type: ptr_type,
+                });
+
+                let local_global_addr = func.create_global_value(ir::GlobalValueData::Load {
+                    base: imported_global_addr,
+                    offset: (vm::ImportedGlobal::offset_global() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                cranelift_wasm::GlobalVariable::Memory {
+                    gv: local_global_addr,
+                    offset: (vm::LocalGlobal::offset_data() as i32).into(),
+                    ty: self.env.get_global(clif_global_index).ty,
+                }
+            }
+        }
+    }
+
+    /// Sets up the necessary preamble definitions in `func` to access the linear memory identified
+    /// by `index`.
+    ///
+    /// The index space covers both imported and locally declared memories.
+    fn make_heap(
+        &mut self,
+        func: &mut ir::Function,
+        clif_mem_index: cranelift_wasm::MemoryIndex,
+    ) -> ir::Heap {
+        let mem_index: MemoryIndex = Converter(clif_mem_index).into();
+        // Create VMContext value.
+        let vmctx = func.create_global_value(ir::GlobalValueData::VMContext);
+        let ptr_type = self.pointer_type();
+
+        match mem_index.local_or_import(self.env.module) {
+            LocalOrImport::Local(local_mem_index) => {
+                let memories_base_addr = func.create_global_value(ir::GlobalValueData::Load {
+                    base: vmctx,
+                    offset: (vm::Ctx::offset_memories() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                let memory_offset = local_mem_index.index() * vm::LocalMemory::size() as usize;
+
+                let memory_struct_addr = func.create_global_value(ir::GlobalValueData::IAddImm {
+                    base: memories_base_addr,
+                    offset: (memory_offset as i64).into(),
+                    global_type: ptr_type,
+                });
+
+                let memory_base_addr = func.create_global_value(ir::GlobalValueData::Load {
+                    base: memory_struct_addr,
+                    offset: (vm::LocalMemory::offset_base() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                func.create_heap(ir::HeapData {
+                    base: memory_base_addr,
+                    min_size: (self.env.module.memories[local_mem_index].min as u64).into(),
+                    offset_guard_size: (LinearMemory::DEFAULT_GUARD_SIZE as u64).into(),
+                    style: ir::HeapStyle::Static {
+                        bound: (LinearMemory::DEFAULT_HEAP_SIZE as u64).into(),
+                    },
+                    index_type: ir::types::I32,
+                })
+            }
+            LocalOrImport::Import(imported_mem_index) => {
+                let imported_memories_base = func.create_global_value(ir::GlobalValueData::Load {
+                    base: vmctx,
+                    offset: (vm::Ctx::offset_imported_memories() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                let imported_memory_offset =
+                    imported_mem_index.index() * vm::ImportedMemory::size() as usize;
+
+                let imported_memory_struct_addr =
+                    func.create_global_value(ir::GlobalValueData::IAddImm {
+                        base: imported_memories_base,
+                        offset: (imported_memory_offset as i64).into(),
+                        global_type: ptr_type,
+                    });
+
+                let local_memory_struct_addr =
+                    func.create_global_value(ir::GlobalValueData::Load {
+                        base: imported_memory_struct_addr,
+                        offset: (vm::ImportedMemory::offset_memory() as i32).into(),
+                        global_type: ptr_type,
+                        readonly: true,
+                    });
+
+                let local_memory_base = func.create_global_value(ir::GlobalValueData::Load {
+                    base: local_memory_struct_addr,
+                    offset: (vm::LocalMemory::offset_base() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                func.create_heap(ir::HeapData {
+                    base: local_memory_base,
+                    min_size: (self.env.module.imported_memories[imported_mem_index].1.min as u64)
+                        .into(),
+                    offset_guard_size: (LinearMemory::DEFAULT_GUARD_SIZE as u64).into(),
+                    style: ir::HeapStyle::Static {
+                        bound: (LinearMemory::DEFAULT_HEAP_SIZE as u64).into(),
+                    },
+                    index_type: ir::types::I32,
+                })
+            }
+        }
+    }
+
+    /// Sets up the necessary preamble definitions in `func` to access the table identified
+    /// by `index`.
+    ///
+    /// The index space covers both imported and locally declared tables.
+    fn make_table(
+        &mut self,
+        func: &mut ir::Function,
+        clif_table_index: cranelift_wasm::TableIndex,
+    ) -> ir::Table {
+        let table_index: TableIndex = Converter(clif_table_index).into();
+        // Create VMContext value.
+        let vmctx = func.create_global_value(ir::GlobalValueData::VMContext);
+        let ptr_type = self.pointer_type();
+
+        match table_index.local_or_import(self.env.module) {
+            LocalOrImport::Local(local_table_index) => {
+                let tables_base = func.create_global_value(ir::GlobalValueData::Load {
+                    base: vmctx,
+                    offset: (vm::Ctx::offset_tables() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                let table_struct_offset =
+                    local_table_index.index() * vm::LocalTable::size() as usize;
+
+                let table_struct_addr = func.create_global_value(ir::GlobalValueData::IAddImm {
+                    base: tables_base,
+                    offset: (table_struct_offset as i64).into(),
+                    global_type: ptr_type,
+                });
+
+                let table_base = func.create_global_value(ir::GlobalValueData::Load {
+                    base: table_struct_addr,
+                    offset: (vm::LocalTable::offset_base() as i32).into(),
+                    global_type: ptr_type,
+                    // we will support growing tables, so this cannot be readonly.
+                    readonly: false,
+                });
+
+                let table_bound = func.create_global_value(ir::GlobalValueData::Load {
+                    base: table_struct_addr,
+                    offset: (vm::LocalTable::offset_current_elements() as i32).into(),
+                    // the number of elements in a table will always fit in an `i32`.
+                    global_type: ir::types::I32,
+                    readonly: false,
+                });
+
+                func.create_table(ir::TableData {
+                    base_gv: table_base,
+                    min_size: (self.env.module.tables[local_table_index].min as u64).into(),
+                    bound_gv: table_bound,
+                    element_size: (vm::Anyfunc::size() as u64).into(),
+                    index_type: ir::types::I32,
+                })
+            }
+            LocalOrImport::Import(imported_table_index) => {
+                let imported_tables_base = func.create_global_value(ir::GlobalValueData::Load {
+                    base: vmctx,
+                    offset: (vm::Ctx::offset_imported_memories() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                let imported_table_struct_offset =
+                    imported_table_index.index() * vm::ImportedTable::size() as usize;
+
+                let imported_table_struct_addr =
+                    func.create_global_value(ir::GlobalValueData::IAddImm {
+                        base: imported_tables_base,
+                        offset: (imported_table_struct_offset as i64).into(),
+                        global_type: ptr_type,
+                    });
+
+                let local_table_struct_addr = func.create_global_value(ir::GlobalValueData::Load {
+                    base: imported_table_struct_addr,
+                    offset: (vm::ImportedTable::offset_table() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                let local_table_base = func.create_global_value(ir::GlobalValueData::Load {
+                    base: local_table_struct_addr,
+                    offset: (vm::LocalTable::offset_base() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: false,
+                });
+
+                let local_table_bound = func.create_global_value(ir::GlobalValueData::Load {
+                    base: local_table_struct_addr,
+                    offset: (vm::LocalTable::offset_current_elements() as i32).into(),
+                    global_type: ir::types::I32,
+                    readonly: false,
+                });
+
+                func.create_table(ir::TableData {
+                    base_gv: local_table_base,
+                    min_size: (self.env.module.imported_tables[imported_table_index].1.min as u64)
+                        .into(),
+                    bound_gv: local_table_bound,
+                    element_size: (vm::Anyfunc::size() as u64).into(),
+                    index_type: ir::types::I32,
+                })
+            }
+        }
+    }
+
+    /// Sets up a signature definition in `func`'s preamble.
+    ///
+    /// Signature may contain additional argument, but arguments marked as ArgumentPurpose::Normal`
+    /// must correspond to the arguments in the wasm signature
+    fn make_indirect_sig(
+        &mut self,
+        func: &mut ir::Function,
+        index: cranelift_wasm::SignatureIndex,
+    ) -> ir::SigRef {
+        // Create a signature reference out of specified signature (with VMContext param added).
+        func.import_signature(self.generate_signature(index))
+    }
+
+    /// Sets up an external function definition in the preamble of `func` that can be used to
+    /// directly call the function `index`.
+    ///
+    /// The index space covers both imported functions and functions defined in the current module.
+    fn make_direct_func(
+        &mut self,
+        func: &mut ir::Function,
+        func_index: cranelift_wasm::FuncIndex,
+    ) -> ir::FuncRef {
+        // Get signature of function.
+        let signature_index = self.env.get_func_type(func_index);
+
+        // Create a signature reference from specified signature (with VMContext param added).
+        let signature = func.import_signature(self.generate_signature(signature_index));
+
+        // Get name of function.
+        let name = ir::ExternalName::user(0, func_index.as_u32());
+
+        // Create function reference from fuction data.
+        func.import_function(ir::ExtFuncData {
+            name,
+            signature,
+            colocated: false,
+        })
+    }
+
+    /// Generates an indirect call IR with `callee` and `call_args`.
+    ///
+    /// Inserts instructions at `pos` to the function `callee` in the table
+    /// `table_index` with WebAssembly signature `sig_index`
+    #[cfg_attr(feature = "cargo-clippy", allow(clippy::too_many_arguments))]
+    fn translate_call_indirect(
+        &mut self,
+        mut pos: FuncCursor,
+        _table_index: cranelift_wasm::TableIndex,
+        table: ir::Table,
+        sig_index: cranelift_wasm::SignatureIndex,
+        sig_ref: ir::SigRef,
+        callee: ir::Value,
+        call_args: &[ir::Value],
+    ) -> cranelift_wasm::WasmResult<ir::Inst> {
+        // Get the pointer type based on machine's pointer size.
+        let ptr_type = self.pointer_type();
+
+        // The `callee` value is an index into a table of Anyfunc structures.
+        let entry_addr = pos.ins().table_addr(ptr_type, table, callee, 0);
+
+        let mflags = ir::MemFlags::trusted();
+
+        let func_ptr = pos.ins().load(
+            ptr_type,
+            mflags,
+            entry_addr,
+            vm::Anyfunc::offset_func() as i32,
+        );
+        let vmctx_ptr = pos.ins().load(
+            ptr_type,
+            mflags,
+            entry_addr,
+            vm::Anyfunc::offset_vmctx() as i32,
+        );
+        let found_sig = pos.ins().load(
+            ir::types::I32,
+            mflags,
+            entry_addr,
+            vm::Anyfunc::offset_sig_id() as i32,
+        );
+
+        pos.ins().trapz(func_ptr, ir::TrapCode::IndirectCallToNull);
+
+        let deduplicated_sig_index = self
+            .env
+            .module
+            .sig_registry
+            .lookup_deduplicated_sigindex(Converter(sig_index).into());
+        let expected_sig = pos
+            .ins()
+            .iconst(ir::types::I32, deduplicated_sig_index.index() as i64);
+        let not_equal_flags = pos.ins().ifcmp(found_sig, expected_sig);
+
+        pos.ins().trapif(
+            ir::condcodes::IntCC::NotEqual,
+            not_equal_flags,
+            ir::TrapCode::BadSignature,
+        );
+
+        // Build a value list for the indirect call instruction containing the call_args
+        // and the vmctx parameter.
+        let mut args = Vec::with_capacity(call_args.len() + 1);
+        args.extend(call_args.iter().cloned());
+        args.push(vmctx_ptr);
+
+        Ok(pos.ins().call_indirect(sig_ref, func_ptr, &args))
+    }
+
+    /// Generates a call IR with `callee` and `call_args` and inserts it at `pos`
+    /// TODO: add support for imported functions
+    fn translate_call(
+        &mut self,
+        mut pos: FuncCursor,
+        clif_callee_index: cranelift_wasm::FuncIndex,
+        callee: ir::FuncRef,
+        call_args: &[ir::Value],
+    ) -> cranelift_wasm::WasmResult<ir::Inst> {
+        let callee_index: FuncIndex = Converter(clif_callee_index).into();
+
+        match callee_index.local_or_import(self.env.module) {
+            LocalOrImport::Local(_) => {
+                // this is an internal function
+                let vmctx = pos
+                    .func
+                    .special_param(ir::ArgumentPurpose::VMContext)
+                    .expect("missing vmctx parameter");
+
+                let mut args = Vec::with_capacity(call_args.len() + 1);
+                args.extend(call_args.iter().cloned());
+                args.push(vmctx);
+
+                Ok(pos.ins().call(callee, &args))
+            }
+            LocalOrImport::Import(imported_func_index) => {
+                let ptr_type = self.pointer_type();
+                // this is an imported function
+                let vmctx = pos.func.create_global_value(ir::GlobalValueData::VMContext);
+
+                let imported_funcs = pos.func.create_global_value(ir::GlobalValueData::Load {
+                    base: vmctx,
+                    offset: (vm::Ctx::offset_imported_funcs() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                let imported_func_offset =
+                    imported_func_index.index() * vm::ImportedFunc::size() as usize;
+
+                let imported_func_struct_addr =
+                    pos.func.create_global_value(ir::GlobalValueData::IAddImm {
+                        base: imported_funcs,
+                        offset: (imported_func_offset as i64).into(),
+                        global_type: ptr_type,
+                    });
+
+                let imported_func_addr = pos.func.create_global_value(ir::GlobalValueData::Load {
+                    base: imported_func_struct_addr,
+                    offset: (vm::ImportedFunc::offset_func() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                let imported_vmctx_addr = pos.func.create_global_value(ir::GlobalValueData::Load {
+                    base: imported_func_struct_addr,
+                    offset: (vm::ImportedFunc::offset_vmctx() as i32).into(),
+                    global_type: ptr_type,
+                    readonly: true,
+                });
+
+                let imported_func_addr = pos.ins().global_value(ptr_type, imported_func_addr);
+                let imported_vmctx_addr = pos.ins().global_value(ptr_type, imported_vmctx_addr);
+
+                let sig_ref = pos.func.dfg.ext_funcs[callee].signature;
+
+                let mut args = Vec::with_capacity(call_args.len() + 1);
+                args.extend(call_args.iter().cloned());
+                args.push(imported_vmctx_addr);
+
+                Ok(pos
+                    .ins()
+                    .call_indirect(sig_ref, imported_func_addr, &args[..]))
+            }
+        }
+    }
+
+    /// Generates code corresponding to wasm `memory.grow`.
+    ///
+    /// `index` refers to the linear memory to query.
+    ///
+    /// `heap` refers to the IR generated by `make_heap`.
+    ///
+    /// `val`  refers the value to grow the memory by.
+    fn translate_memory_grow(
+        &mut self,
+        mut pos: FuncCursor,
+        index: cranelift_wasm::MemoryIndex,
+        _heap: ir::Heap,
+        val: ir::Value,
+    ) -> cranelift_wasm::WasmResult<ir::Value> {
+        let signature = pos.func.import_signature(ir::Signature {
+            call_conv: self.target_config().default_call_conv,
+            params: vec![
+                ir::AbiParam::new(ir::types::I32),
+                ir::AbiParam::new(ir::types::I32),
+                ir::AbiParam::special(self.pointer_type(), ir::ArgumentPurpose::VMContext),
+            ],
+            returns: vec![ir::AbiParam::new(ir::types::I32)],
+        });
+
+        let grow_mem_func = pos.func.import_function(ir::ExtFuncData {
+            // `ir::ExternalName` for static_grow_memory`
+            name: ir::ExternalName::user(1, 0),
+            signature,
+            colocated: false,
+        });
+
+        // Create a memory index value.
+        let memory_index = pos.ins().iconst(ir::types::I32, index.index() as i64);
+
+        // Create a VMContext value.
+        let vmctx = pos
+            .func
+            .special_param(ir::ArgumentPurpose::VMContext)
+            .expect("missing vmctx parameter");
+
+        // Insert call instructions for `grow_memory`.
+        let call_inst = pos.ins().call(grow_mem_func, &[memory_index, val, vmctx]);
+
+        // Return value.
+        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
+    }
+
+    /// Generates code corresponding to wasm `memory.size`.
+    ///
+    /// `index` refers to the linear memory to query.
+    ///
+    /// `heap` refers to the IR generated by `make_heap`.
+    fn translate_memory_size(
+        &mut self,
+        mut pos: FuncCursor,
+        index: cranelift_wasm::MemoryIndex,
+        _heap: ir::Heap,
+    ) -> cranelift_wasm::WasmResult<ir::Value> {
+        let signature = pos.func.import_signature(ir::Signature {
+            call_conv: self.target_config().default_call_conv,
+            params: vec![
+                ir::AbiParam::new(ir::types::I32),
+                ir::AbiParam::special(self.pointer_type(), ir::ArgumentPurpose::VMContext),
+            ],
+            returns: vec![ir::AbiParam::new(ir::types::I32)],
+        });
+
+        let size_mem_func = pos.func.import_function(ir::ExtFuncData {
+            // `ir::ExternalName` for static_grow_memory`
+            name: ir::ExternalName::user(1, 1),
+            signature,
+            colocated: false,
+        });
+
+        // Create a memory index value.
+        let memory_index = pos.ins().iconst(ir::types::I32, index.index() as i64);
+
+        // Create a VMContext value.
+        let vmctx = pos
+            .func
+            .special_param(ir::ArgumentPurpose::VMContext)
+            .expect("missing vmctx parameter");
+
+        // Insert call instructions for `grow_memory`.
+        let call_inst = pos.ins().call(size_mem_func, &[memory_index, vmctx]);
+
+        // Return value.
+        Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
+    }
+}

lib/clif-backend/src/lib.rs

@@ -1,8 +1,10 @@
-pub mod codegen;
+// pub mod codegen;
+mod func_env;
 mod libcalls;
+mod module;
+mod module_env;
 mod relocation;
 mod resolver;
-// mod module;
 
 use cranelift_codegen::{
     isa,
@@ -12,9 +14,6 @@ use target_lexicon::Triple;
 use wasmer_runtime::{backend::Compiler, module::ModuleInner};
 use wasmparser::{self, WasmDecoder};
 
-use self::codegen::converter;
-use self::codegen::CraneliftModule;
-
 pub struct CraneliftCompiler {}
 
 impl CraneliftCompiler {
@@ -29,14 +28,12 @@ impl Compiler for CraneliftCompiler {
         validate(wasm)?;
 
         let isa = get_isa();
-        // Generate a Cranlift module from wasm binary
-        let cranelift_module = CraneliftModule::from_bytes(&wasm.to_vec(), isa.frontend_config())?;
 
-        // Convert Cranelift module to wasmer module
-        let wasmer_module = converter::convert_module(cranelift_module);
+        let mut module = module::Module::empty();
+        let module_env = module_env::ModuleEnv::new(&mut module, &*isa);
+        let func_bodies = module_env.translate(wasm)?;
 
-        // Return new wasmer module
-        Ok(wasmer_module)
+        module.compile(&*isa, func_bodies)
     }
 }
 
@@ -61,11 +58,11 @@ fn validate(bytes: &[u8]) -> Result<(), String> {
     loop {
         let state = parser.read();
         match *state {
-            wasmparser::ParserState::EndWasm => return Ok(()),
+            wasmparser::ParserState::EndWasm => break Ok(()),
             wasmparser::ParserState::Error(err) => {
                 return Err(format!("Validation error: {}", err.message));
             }
-            _ => (),
+            _ => {}
         }
     }
 }

lib/clif-backend/src/module.rs

@@ -1,20 +1,158 @@
+use crate::resolver::FuncResolverBuilder;
+use cranelift_codegen::{ir, isa};
+use cranelift_entity::EntityRef;
+use cranelift_wasm;
+use hashbrown::HashMap;
+use std::{
+    ops::{Deref, DerefMut},
+    ptr::NonNull,
+};
 use wasmer_runtime::{
+    backend::FuncResolver,
     backend::SigRegistry,
-    memory::LinearMemory,
-    module::{
-        DataInitializer, ExportIndex, ImportName, ModuleInner, TableInitializer,
-    },
+    module::ModuleInner,
+    structures::{Map, TypedIndex},
     types::{
-        ElementType, FuncIndex, FuncSig,
-        Global, GlobalDesc, GlobalIndex,
-        Initializer, Map, TypedIndex, Memory,
-        MemoryIndex as WasmerMemoryIndex, SigIndex as WasmerSignatureIndex, Table as WasmerTable,
-        TableIndex as WasmerTableIndex, Type as WasmerType, GlobalInit as WasmerGlobalInit,
+        FuncIndex, FuncSig, GlobalIndex, LocalFuncIndex, MemoryIndex, SigIndex, TableIndex, Type,
     },
-    vm::{self, Ctx as WasmerVMContext},
+    vm,
 };
 
-/// This is a wasmer module.
-pub struct Module {
+struct PlaceholderFuncResolver;
 
+impl FuncResolver for PlaceholderFuncResolver {
+    fn get(
+        &self,
+        _module: &ModuleInner,
+        _local_func_index: LocalFuncIndex,
+    ) -> Option<NonNull<vm::Func>> {
+        None
+    }
+}
+
+/// This contains all of the items in a `ModuleInner` except the `func_resolver`.
+pub struct Module {
+    module: ModuleInner,
+}
+
+impl Module {
+    pub fn empty() -> Self {
+        Self {
+            module: ModuleInner {
+                // this is a placeholder
+                func_resolver: Box::new(PlaceholderFuncResolver),
+                memories: Map::new(),
+                globals: Map::new(),
+                tables: Map::new(),
+
+                imported_functions: Map::new(),
+                imported_memories: Map::new(),
+                imported_tables: Map::new(),
+                imported_globals: Map::new(),
+
+                exports: HashMap::new(),
+
+                data_initializers: Vec::new(),
+                elem_initializers: Vec::new(),
+
+                start_func: None,
+
+                func_assoc: Map::new(),
+                sig_registry: SigRegistry::new(),
+            },
+        }
+    }
+
+    pub fn compile(
+        mut self,
+        isa: &isa::TargetIsa,
+        functions: Map<LocalFuncIndex, ir::Function>,
+    ) -> Result<ModuleInner, String> {
+        // we have to deduplicate `module.func_assoc`
+        let func_assoc = &mut self.module.func_assoc;
+        let sig_registry = &self.module.sig_registry;
+        func_assoc.iter_mut().for_each(|(_, sig_index)| {
+            *sig_index = sig_registry.lookup_deduplicated_sigindex(*sig_index);
+        });
+
+        let func_resolver_builder = FuncResolverBuilder::new(isa, functions)?;
+        self.module.func_resolver = Box::new(func_resolver_builder.finalize()?);
+        Ok(self.module)
+    }
+}
+
+impl Deref for Module {
+    type Target = ModuleInner;
+
+    fn deref(&self) -> &ModuleInner {
+        &self.module
+    }
+}
+
+impl DerefMut for Module {
+    fn deref_mut(&mut self) -> &mut ModuleInner {
+        &mut self.module
+    }
+}
+
+pub struct Converter<T>(pub T);
+
+macro_rules! convert_clif_to_runtime_index {
+    ($clif_index:ident, $runtime_index:ident) => {
+        impl From<Converter<cranelift_wasm::$clif_index>> for $runtime_index {
+            fn from(clif_index: Converter<cranelift_wasm::$clif_index>) -> Self {
+                $runtime_index::new(clif_index.0.index())
+            }
+        }
+
+        impl From<Converter<$runtime_index>> for cranelift_wasm::$clif_index {
+            fn from(runtime_index: Converter<$runtime_index>) -> Self {
+                cranelift_wasm::$clif_index::new(runtime_index.0.index())
+            }
+        }
+    };
+    ($(($clif_index:ident: $runtime_index:ident),)*) => {
+        $(
+            convert_clif_to_runtime_index!($clif_index, $runtime_index);
+        )*
+    };
+}
+
+convert_clif_to_runtime_index![
+    (FuncIndex: FuncIndex),
+    (MemoryIndex: MemoryIndex),
+    (TableIndex: TableIndex),
+    (GlobalIndex: GlobalIndex),
+    (SignatureIndex: SigIndex),
+];
+
+impl<'a> From<Converter<&'a ir::Signature>> for FuncSig {
+    fn from(signature: Converter<&'a ir::Signature>) -> Self {
+        FuncSig {
+            params: signature
+                .0
+                .params
+                .iter()
+                .map(|param| Converter(param.value_type).into())
+                .collect(),
+            returns: signature
+                .0
+                .returns
+                .iter()
+                .map(|ret| Converter(ret.value_type).into())
+                .collect(),
+        }
+    }
+}
+
+impl From<Converter<ir::Type>> for Type {
+    fn from(ty: Converter<ir::Type>) -> Self {
+        match ty.0 {
+            ir::types::I32 => Type::I32,
+            ir::types::I64 => Type::I64,
+            ir::types::F32 => Type::F32,
+            ir::types::F64 => Type::F64,
+            _ => panic!("unsupported wasm type"),
+        }
+    }
 }

lib/clif-backend/src/module_env.rs

@@ -0,0 +1,364 @@
+use crate::{
+    func_env::FuncEnv,
+    module::{Converter, Module},
+};
+use cranelift_codegen::{ir, isa};
+use cranelift_wasm::{self, translate_module, FuncTranslator, ModuleEnvironment};
+use wasmer_runtime::{
+    module::{DataInitializer, ExportIndex, ImportName, TableInitializer},
+    structures::{Map, TypedIndex},
+    types::{
+        ElementType, Global, GlobalDesc, GlobalIndex, Initializer, LocalFuncIndex, LocalOrImport,
+        Memory, SigIndex, Table, Value,
+    },
+};
+
+pub struct ModuleEnv<'module, 'isa> {
+    pub module: &'module mut Module,
+    isa: &'isa isa::TargetIsa,
+    pub signatures: Map<SigIndex, ir::Signature>,
+    globals: Map<GlobalIndex, cranelift_wasm::Global>,
+    func_bodies: Map<LocalFuncIndex, ir::Function>,
+}
+
+impl<'module, 'isa> ModuleEnv<'module, 'isa> {
+    pub fn new(module: &'module mut Module, isa: &'isa isa::TargetIsa) -> Self {
+        Self {
+            module,
+            isa,
+            signatures: Map::new(),
+            globals: Map::new(),
+            func_bodies: Map::new(),
+        }
+    }
+
+    pub fn translate(mut self, wasm: &[u8]) -> Result<Map<LocalFuncIndex, ir::Function>, String> {
+        translate_module(wasm, &mut self).map_err(|e| e.to_string())?;
+        Ok(self.func_bodies)
+    }
+}
+
+impl<'module, 'isa, 'data> ModuleEnvironment<'data> for ModuleEnv<'module, 'isa> {
+    /// Get the information needed to produce Cranelift IR for the current target.
+    fn target_config(&self) -> isa::TargetFrontendConfig {
+        self.isa.frontend_config()
+    }
+
+    /// Declares a function signature to the environment.
+    fn declare_signature(&mut self, sig: &ir::Signature) {
+        self.signatures.push(sig.clone());
+        self.module.sig_registry.register(Converter(sig).into());
+    }
+
+    /// Return the signature with the given index.
+    fn get_signature(&self, sig_index: cranelift_wasm::SignatureIndex) -> &ir::Signature {
+        &self.signatures[Converter(sig_index).into()]
+    }
+
+    /// Declares a function import to the environment.
+    fn declare_func_import(
+        &mut self,
+        sig_index: cranelift_wasm::SignatureIndex,
+        namespace: &'data str,
+        name: &'data str,
+    ) {
+        self.module.func_assoc.push(Converter(sig_index).into());
+
+        // Add import names to list of imported functions
+        self.module.imported_functions.push(ImportName {
+            namespace: namespace.to_string(),
+            name: name.to_string(),
+        });
+    }
+
+    /// Return the number of imported funcs.
+    fn get_num_func_imports(&self) -> usize {
+        self.module.imported_functions.len()
+    }
+
+    /// Declares the type (signature) of a local function in the module.
+    fn declare_func_type(&mut self, sig_index: cranelift_wasm::SignatureIndex) {
+        self.module.func_assoc.push(Converter(sig_index).into());
+    }
+
+    /// Return the signature index for the given function index.
+    fn get_func_type(
+        &self,
+        func_index: cranelift_wasm::FuncIndex,
+    ) -> cranelift_wasm::SignatureIndex {
+        Converter(self.module.func_assoc[Converter(func_index).into()]).into()
+    }
+
+    /// Declares a global to the environment.
+    fn declare_global(&mut self, global: cranelift_wasm::Global) {
+        use cranelift_wasm::GlobalInit;
+
+        let desc = GlobalDesc {
+            mutable: global.mutability,
+            ty: Converter(global.ty).into(),
+        };
+
+        let init = match global.initializer {
+            GlobalInit::I32Const(x) => Initializer::Const(Value::I32(x)),
+            GlobalInit::I64Const(x) => Initializer::Const(Value::I64(x)),
+            GlobalInit::F32Const(x) => Initializer::Const(Value::F32(f32::from_bits(x))),
+            GlobalInit::F64Const(x) => Initializer::Const(Value::F64(f64::from_bits(x))),
+            GlobalInit::GetGlobal(global_index) => {
+                assert!(!desc.mutable);
+                let global_index: GlobalIndex = Converter(global_index).into();
+                let imported_global_index = global_index
+                    .local_or_import(self.module)
+                    .import()
+                    .expect("invalid global initializer when declaring an imported global");
+                Initializer::GetGlobal(imported_global_index)
+            }
+            _ => panic!("invalid global initializer when declaring a local global"),
+        };
+
+        // Add global ir to the list of globals
+        self.module.globals.push(Global { desc, init });
+
+        self.globals.push(global);
+    }
+
+    /// Declares a global import to the environment.
+    fn declare_global_import(
+        &mut self,
+        global: cranelift_wasm::Global,
+        namespace: &'data str,
+        name: &'data str,
+    ) {
+        assert!(match global.initializer {
+            cranelift_wasm::GlobalInit::Import => true,
+            _ => false,
+        });
+
+        let import_name = ImportName {
+            namespace: namespace.to_string(),
+            name: name.to_string(),
+        };
+
+        let desc = GlobalDesc {
+            mutable: global.mutability,
+            ty: Converter(global.ty).into(),
+        };
+
+        // Add global ir to the list of globals
+        self.module.imported_globals.push((import_name, desc));
+
+        self.globals.push(global);
+    }
+
+    /// Return the global for the given global index.
+    fn get_global(&self, global_index: cranelift_wasm::GlobalIndex) -> &cranelift_wasm::Global {
+        &self.globals[Converter(global_index).into()]
+    }
+
+    /// Declares a table to the environment.
+    fn declare_table(&mut self, table: cranelift_wasm::Table) {
+        use cranelift_wasm::TableElementType;
+        // Add table ir to the list of tables
+        self.module.tables.push(Table {
+            ty: match table.ty {
+                TableElementType::Func => ElementType::Anyfunc,
+                _ => unimplemented!(),
+            },
+            min: table.minimum,
+            max: table.maximum,
+        });
+    }
+
+    /// Declares a table import to the environment.
+    fn declare_table_import(
+        &mut self,
+        table: cranelift_wasm::Table,
+        namespace: &'data str,
+        name: &'data str,
+    ) {
+        use cranelift_wasm::TableElementType;
+
+        let import_name = ImportName {
+            namespace: namespace.to_string(),
+            name: name.to_string(),
+        };
+
+        let imported_table = Table {
+            ty: match table.ty {
+                TableElementType::Func => ElementType::Anyfunc,
+                _ => unimplemented!(),
+            },
+            min: table.minimum,
+            max: table.maximum,
+        };
+
+        // Add import names to list of imported tables
+        self.module
+            .imported_tables
+            .push((import_name, imported_table));
+    }
+
+    /// Fills a declared table with references to functions in the module.
+    fn declare_table_elements(
+        &mut self,
+        table_index: cranelift_wasm::TableIndex,
+        base: Option<cranelift_wasm::GlobalIndex>,
+        offset: usize,
+        elements: Vec<cranelift_wasm::FuncIndex>,
+    ) {
+        // Convert Cranelift GlobalIndex to wamser GlobalIndex
+        // let base = base.map(|index| WasmerGlobalIndex::new(index.index()));
+        let base = match base {
+            Some(global_index) => {
+                let global_index: GlobalIndex = Converter(global_index).into();
+                Initializer::GetGlobal(match global_index.local_or_import(self.module) {
+                    LocalOrImport::Import(imported_global_index) => imported_global_index,
+                    LocalOrImport::Local(_) => {
+                        panic!("invalid global initializer when declaring an imported global")
+                    }
+                })
+            }
+            None => Initializer::Const((offset as i32).into()),
+        };
+
+        // Add table initializer to list of table initializers
+        self.module.elem_initializers.push(TableInitializer {
+            table_index: Converter(table_index).into(),
+            base,
+            elements: elements
+                .iter()
+                .map(|&func_index| Converter(func_index).into())
+                .collect(),
+        });
+    }
+
+    /// Declares a memory to the environment
+    fn declare_memory(&mut self, memory: cranelift_wasm::Memory) {
+        self.module.memories.push(Memory {
+            min: memory.minimum,
+            max: memory.maximum,
+            shared: memory.shared,
+        });
+    }
+
+    /// Declares a memory import to the environment.
+    fn declare_memory_import(
+        &mut self,
+        memory: cranelift_wasm::Memory,
+        namespace: &'data str,
+        name: &'data str,
+    ) {
+        let import_name = ImportName {
+            namespace: namespace.to_string(),
+            name: name.to_string(),
+        };
+
+        let memory = Memory {
+            min: memory.minimum,
+            max: memory.maximum,
+            shared: memory.shared,
+        };
+
+        // Add import names to list of imported memories
+        self.module.imported_memories.push((import_name, memory));
+    }
+
+    /// Fills a declared memory with bytes at module instantiation.
+    fn declare_data_initialization(
+        &mut self,
+        memory_index: cranelift_wasm::MemoryIndex,
+        base: Option<cranelift_wasm::GlobalIndex>,
+        offset: usize,
+        data: &'data [u8],
+    ) {
+        // Convert Cranelift GlobalIndex to wamser GlobalIndex
+        let base = match base {
+            Some(global_index) => {
+                let global_index: GlobalIndex = Converter(global_index).into();
+                Initializer::GetGlobal(match global_index.local_or_import(self.module) {
+                    LocalOrImport::Import(imported_global_index) => imported_global_index,
+                    LocalOrImport::Local(_) => {
+                        panic!("invalid global initializer when declaring an imported global")
+                    }
+                })
+            }
+            None => Initializer::Const((offset as i32).into()),
+        };
+
+        // Add data initializer to list of data initializers
+        self.module.data_initializers.push(DataInitializer {
+            memory_index: Converter(memory_index).into(),
+            base,
+            data: data.to_vec(),
+        });
+    }
+
+    /// Declares a function export to the environment.
+    fn declare_func_export(&mut self, func_index: cranelift_wasm::FuncIndex, name: &'data str) {
+        self.module.exports.insert(
+            name.to_string(),
+            ExportIndex::Func(Converter(func_index).into()),
+        );
+    }
+    /// Declares a table export to the environment.
+    fn declare_table_export(&mut self, table_index: cranelift_wasm::TableIndex, name: &'data str) {
+        self.module.exports.insert(
+            name.to_string(),
+            ExportIndex::Table(Converter(table_index).into()),
+        );
+    }
+    /// Declares a memory export to the environment.
+    fn declare_memory_export(
+        &mut self,
+        memory_index: cranelift_wasm::MemoryIndex,
+        name: &'data str,
+    ) {
+        self.module.exports.insert(
+            name.to_string(),
+            ExportIndex::Memory(Converter(memory_index).into()),
+        );
+    }
+    /// Declares a global export to the environment.
+    fn declare_global_export(
+        &mut self,
+        global_index: cranelift_wasm::GlobalIndex,
+        name: &'data str,
+    ) {
+        self.module.exports.insert(
+            name.to_string(),
+            ExportIndex::Global(Converter(global_index).into()),
+        );
+    }
+
+    /// Declares a start function.
+    fn declare_start_func(&mut self, func_index: cranelift_wasm::FuncIndex) {
+        self.module.start_func = Some(Converter(func_index).into());
+    }
+
+    /// Provides the contents of a function body.
+    fn define_function_body(&mut self, body_bytes: &'data [u8]) -> cranelift_wasm::WasmResult<()> {
+        let mut func_translator = FuncTranslator::new();
+
+        let func_body = {
+            let mut func_env = FuncEnv::new(self);
+            let func_index = self.func_bodies.next_index();
+            let name = ir::ExternalName::user(0, func_index.index() as u32);
+
+            let sig = func_env.generate_signature(
+                self.get_func_type(Converter(func_index.convert_up(self.module)).into()),
+            );
+
+            let mut func = ir::Function::with_name_signature(name, sig);
+
+            println!("translating function");
+            func_translator.translate(body_bytes, &mut func, &mut func_env)?;
+            println!("done translating function");
+
+            func
+        };
+
+        // Add function body to list of function bodies.
+        self.func_bodies.push(func_body);
+
+        Ok(())
+    }
+}

lib/clif-backend/src/relocation.rs

@@ -4,6 +4,7 @@
 //! function addrs in runtime with the functions we need.
 use cranelift_codegen::binemit;
 use cranelift_codegen::ir::{self, ExternalName, LibCall, SourceLoc, TrapCode};
+use wasmer_runtime::{structures::TypedIndex, types::LocalFuncIndex};
 
 pub use cranelift_codegen::binemit::Reloc;
 
@@ -22,11 +23,11 @@ pub struct Relocation {
 /// Specify the type of relocation
 #[derive(Debug, Clone)]
 pub enum RelocationType {
-    Normal(u32),
+    Normal(LocalFuncIndex),
     Intrinsic(String),
     LibCall(LibCall),
-    GrowMemory,
-    CurrentMemory,
+    StaticGrowMemory,
+    StaticCurrentMemory,
 }
 
 /// Implementation of a relocation sink that just saves all the information for later
@@ -61,22 +62,33 @@ impl binemit::RelocSink for RelocSink {
                     reloc,
                     offset,
                     addend,
-                    target: RelocationType::Normal(index as _),
+                    target: RelocationType::Normal(LocalFuncIndex::new(index as usize)),
                 });
             }
-            ExternalName::TestCase { length, ascii } => {
-                let (slice, _) = ascii.split_at(length as usize);
-                let name = String::from_utf8(slice.to_vec()).unwrap();
-                let relocation_type = match name.as_str() {
-                    "current_memory" => RelocationType::CurrentMemory,
-                    "grow_memory" => RelocationType::GrowMemory,
-                    _ => RelocationType::Intrinsic(name),
+            ExternalName::User {
+                namespace: 1,
+                index,
+            } => {
+                let target = match index {
+                    0 => RelocationType::StaticGrowMemory,
+                    1 => RelocationType::StaticCurrentMemory,
+                    _ => unimplemented!(),
                 };
                 self.func_relocs.push(Relocation {
                     reloc,
                     offset,
                     addend,
-                    target: relocation_type,
+                    target,
+                });
+            }
+            ExternalName::TestCase { length, ascii } => {
+                let (slice, _) = ascii.split_at(length as usize);
+                let name = String::from_utf8(slice.to_vec()).unwrap();
+                self.func_relocs.push(Relocation {
+                    reloc,
+                    offset,
+                    addend,
+                    target: RelocationType::Intrinsic(name),
                 });
             }
             ExternalName::LibCall(libcall) => {

lib/clif-backend/src/resolver.rs

@@ -7,7 +7,8 @@ use std::ptr::{write_unaligned, NonNull};
 use wasmer_runtime::{
     self,
     backend::{self, Mmap, Protect},
-    types::{LocalFuncIndex, Map, TypedIndex},
+    structures::Map,
+    types::LocalFuncIndex,
     vm, vmcalls,
 };
 
@@ -21,8 +22,7 @@ pub struct FuncResolverBuilder {
 impl FuncResolverBuilder {
     pub fn new(
         isa: &isa::TargetIsa,
-        function_bodies: Vec<ir::Function>,
-        num_imported_funcs: usize,
+        function_bodies: Map<LocalFuncIndex, ir::Function>,
     ) -> Result<Self, String> {
         let mut compiled_functions: Vec<Vec<u8>> = Vec::with_capacity(function_bodies.len());
         let mut relocations = Map::with_capacity(function_bodies.len());
@@ -31,7 +31,7 @@ impl FuncResolverBuilder {
         let mut ctx = Context::new();
         let mut total_size = 0;
 
-        for func in function_bodies.into_iter() {
+        for (_, func) in function_bodies {
             ctx.func = func;
             let mut code_buf = Vec::new();
             let mut reloc_sink = RelocSink::new();
@@ -71,11 +71,7 @@ impl FuncResolverBuilder {
         }
 
         Ok(Self {
-            resolver: FuncResolver {
-                num_imported_funcs,
-                map,
-                memory,
-            },
+            resolver: FuncResolver { map, memory },
             relocations,
             trap_sinks,
         })
@@ -85,17 +81,14 @@ impl FuncResolverBuilder {
         for (index, relocs) in self.relocations.iter() {
             for ref reloc in relocs {
                 let target_func_address: isize = match reloc.target {
-                    RelocationType::Normal(func_index) => {
+                    RelocationType::Normal(local_func_index) => {
                         // This will always be an internal function
                         // because imported functions are not
                         // called in this way.
-                        self.resolver
-                            .lookup(FuncIndex::new(func_index as _))
-                            .unwrap()
-                            .as_ptr() as isize
+                        self.resolver.lookup(local_func_index).unwrap().as_ptr() as isize
                     }
-                    RelocationType::CurrentMemory => vmcalls::memory_size as isize,
-                    RelocationType::GrowMemory => vmcalls::memory_grow_static as isize,
+                    RelocationType::StaticCurrentMemory => vmcalls::memory_size as isize,
+                    RelocationType::StaticGrowMemory => vmcalls::memory_grow_static as isize,
                     RelocationType::LibCall(libcall) => match libcall {
                         ir::LibCall::CeilF32 => libcalls::ceilf32 as isize,
                         ir::LibCall::FloorF32 => libcalls::floorf32 as isize,
@@ -157,7 +150,6 @@ impl FuncResolverBuilder {
 
 /// Resolves a function index to a function address.
 pub struct FuncResolver {
-    num_imported_funcs: usize,
     map: Map<LocalFuncIndex, usize>,
     memory: Mmap,
 }
@@ -176,7 +168,7 @@ impl backend::FuncResolver for FuncResolver {
     fn get(
         &self,
         _module: &wasmer_runtime::module::ModuleInner,
-        index: FuncIndex,
+        index: LocalFuncIndex,
     ) -> Option<NonNull<vm::Func>> {
         self.lookup(index)
     }

lib/runtime/src/backing.rs

@@ -42,7 +42,7 @@ impl LocalBacking {
 
         let vm_memories = Self::finalize_memories(module, imports, &mut memories);
         let vm_tables = Self::finalize_tables(module, imports, &mut tables, vmctx);
-        let vm_globals = Self::finalize_globals(module, globals);
+        let vm_globals = Self::finalize_globals(module, imports, globals);
 
         Self {
             memories,
@@ -86,16 +86,27 @@ impl LocalBacking {
             .iter()
             .filter(|init| init.data.len() > 0)
         {
-            assert!(init.base.is_none(), "global base not supported yet");
+            let init_base = match init.base {
+                Initializer::Const(Value::I32(offset)) => offset as u32,
+                Initializer::Const(_) => panic!("a const initializer must be the i32 type"),
+                Initializer::GetGlobal(imported_global_index) => {
+                    if module.imported_globals[imported_global_index].1.ty == Type::I32 {
+                        unsafe { (*imports.globals[imported_global_index].global).data as u32 }
+                    } else {
+                        panic!("unsupported global type for initialzer")
+                    }
+                }
+            } as usize;
 
             match init.memory_index.local_or_import(module) {
                 LocalOrImport::Local(local_memory_index) => {
                     let memory_desc = &module.memories[local_memory_index];
-                    let data_top = init.offset + init.data.len();
-                    assert!(memory_desc.min as usize >= data_top);
+                    let data_top = init_base + init.data.len();
+                    println!("data_top: {}", data_top);
+                    assert!((memory_desc.min * LinearMemory::PAGE_SIZE) as usize >= data_top);
                     let mem: &mut LinearMemory = &mut memories[local_memory_index];
 
-                    let to_init = &mut mem[init.offset..init.offset + init.data.len()];
+                    let to_init = &mut mem[init_base..init_base + init.data.len()];
                     to_init.copy_from_slice(&init.data);
                 }
                 LocalOrImport::Import(imported_memory_index) => {
@@ -130,12 +141,12 @@ impl LocalBacking {
         tables: &mut SliceMap<LocalTableIndex, TableBacking>,
         vmctx: *mut vm::Ctx,
     ) -> BoxedMap<LocalTableIndex, vm::LocalTable> {
-        for init in &module.table_initializers {
+        for init in &module.elem_initializers {
             let init_base = match init.base {
                 Initializer::Const(Value::I32(offset)) => offset as u32,
                 Initializer::Const(_) => panic!("a const initializer must be the i32 type"),
                 Initializer::GetGlobal(imported_global_index) => {
-                    if module.imported_globals[imported_global_index].1.desc.ty == Type::I32 {
+                    if module.imported_globals[imported_global_index].1.ty == Type::I32 {
                         unsafe { (*imports.globals[imported_global_index].global).data as u32 }
                     } else {
                         panic!("unsupported global type for initialzer")
@@ -243,14 +254,20 @@ impl LocalBacking {
 
     fn finalize_globals(
         module: &ModuleInner,
+        imports: &ImportBacking,
         mut globals: BoxedMap<LocalGlobalIndex, vm::LocalGlobal>,
     ) -> BoxedMap<LocalGlobalIndex, vm::LocalGlobal> {
-        for ((_, to), (_, from)) in globals.iter_mut().zip(module.globals.into_iter()) {
+        for ((_, to), (_, from)) in globals.iter_mut().zip(module.globals.iter()) {
             to.data = match from.init {
-                Value::I32(x) => x as u64,
-                Value::I64(x) => x as u64,
+                Initializer::Const(ref value) => match value {
+                    Value::I32(x) => *x as u64,
+                    Value::I64(x) => *x as u64,
                     Value::F32(x) => x.to_bits() as u64,
                     Value::F64(x) => x.to_bits(),
+                },
+                Initializer::GetGlobal(imported_global_index) => unsafe {
+                    (*imports.globals[imported_global_index].global).data
+                },
             };
         }
 
@@ -416,13 +433,13 @@ fn import_globals(
     imports: &mut Imports,
 ) -> Result<BoxedMap<ImportedGlobalIndex, vm::ImportedGlobal>, String> {
     let mut globals = Map::with_capacity(module.imported_globals.len());
-    for (_, (ImportName { namespace, name }, imported_global)) in &module.imported_globals {
+    for (_, (ImportName { namespace, name }, imported_global_desc)) in &module.imported_globals {
         let import = imports
             .get_namespace(namespace)
             .and_then(|namespace| namespace.get_export(name));
         match import {
             Some(Export::Global { local, global }) => {
-                if global == imported_global.desc {
+                if global == *imported_global_desc {
                     globals.push(vm::ImportedGlobal {
                         global: local.inner(),
                     });

lib/runtime/src/instance.rs

@@ -277,13 +277,16 @@ impl InstanceInner {
                 )
             }
             LocalOrImport::Import(imported_global_index) => {
-                let &(_, imported_global) = &module
+                let &(_, imported_global_desc) = &module
                     .imported_globals
                     .get(imported_global_index)
                     .expect("missing imported global index");
                 let vm::ImportedGlobal { global } =
                     &self.import_backing.globals[imported_global_index];
-                (unsafe { GlobalPointer::new(*global) }, imported_global.desc)
+                (
+                    unsafe { GlobalPointer::new(*global) },
+                    *imported_global_desc,
+                )
             }
         }
     }

lib/runtime/src/module.rs

@@ -4,7 +4,7 @@ use crate::{
     sig_registry::SigRegistry,
     structures::Map,
     types::{
-        FuncIndex, Global, GlobalIndex, ImportedFuncIndex, ImportedGlobal, ImportedGlobalIndex,
+        FuncIndex, Global, GlobalDesc, GlobalIndex, ImportedFuncIndex, ImportedGlobalIndex,
         ImportedMemoryIndex, ImportedTableIndex, Initializer, LocalGlobalIndex, LocalMemoryIndex,
         LocalTableIndex, Memory, MemoryIndex, SigIndex, Table, TableIndex,
     },
@@ -26,12 +26,13 @@ pub struct ModuleInner {
     pub imported_functions: Map<ImportedFuncIndex, ImportName>,
     pub imported_memories: Map<ImportedMemoryIndex, (ImportName, Memory)>,
     pub imported_tables: Map<ImportedTableIndex, (ImportName, Table)>,
-    pub imported_globals: Map<ImportedGlobalIndex, (ImportName, ImportedGlobal)>,
+    pub imported_globals: Map<ImportedGlobalIndex, (ImportName, GlobalDesc)>,
 
     pub exports: HashMap<String, ExportIndex>,
 
     pub data_initializers: Vec<DataInitializer>,
-    pub table_initializers: Vec<TableInitializer>,
+    pub elem_initializers: Vec<TableInitializer>,
+
     pub start_func: Option<FuncIndex>,
 
     pub func_assoc: Map<FuncIndex, SigIndex>,
@@ -82,10 +83,8 @@ pub enum ExportIndex {
 pub struct DataInitializer {
     /// The index of the memory to initialize.
     pub memory_index: MemoryIndex,
-    /// Optionally a globalvalue base to initialize at.
-    pub base: Option<GlobalIndex>,
-    /// A constant offset to initialize at.
-    pub offset: usize,
+    /// Either a constant offset or a `get_global`
+    pub base: Initializer,
     /// The initialization data.
     pub data: Vec<u8>,
 }

lib/runtime/src/structures/map.rs

@@ -4,7 +4,7 @@ use std::{
     marker::PhantomData,
     mem,
     ops::{Deref, DerefMut},
-    slice,
+    slice, vec,
 };
 
 /// Dense item map
@@ -45,6 +45,10 @@ where
         K::new(len)
     }
 
+    pub fn next_index(&self) -> K {
+        K::new(self.len())
+    }
+
     pub fn reserve_exact(&mut self, size: usize) {
         self.elems.reserve_exact(size);
     }
@@ -105,6 +109,49 @@ where
     }
 }
 
+pub struct IntoIter<K, V>
+where
+    K: TypedIndex,
+{
+    enumerated: iter::Enumerate<vec::IntoIter<V>>,
+    _marker: PhantomData<K>,
+}
+
+impl<K, V> IntoIter<K, V>
+where
+    K: TypedIndex,
+{
+    pub(in crate::structures) fn new(into_iter: vec::IntoIter<V>) -> Self {
+        Self {
+            enumerated: into_iter.enumerate(),
+            _marker: PhantomData,
+        }
+    }
+}
+
+impl<K, V> Iterator for IntoIter<K, V>
+where
+    K: TypedIndex,
+{
+    type Item = (K, V);
+
+    fn next(&mut self) -> Option<(K, V)> {
+        self.enumerated.next().map(|(i, v)| (K::new(i), v))
+    }
+}
+
+impl<K, V> IntoIterator for Map<K, V>
+where
+    K: TypedIndex,
+{
+    type Item = (K, V);
+    type IntoIter = IntoIter<K, V>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        IntoIter::new(self.elems.into_iter())
+    }
+}
+
 impl<'a, K, V> IntoIterator for &'a Map<K, V>
 where
     K: TypedIndex,

lib/runtime/src/structures/mod.rs

@@ -7,6 +7,8 @@ pub use self::map::{Iter, IterMut, Map};
 pub use self::slice::SliceMap;
 
 pub trait TypedIndex {
+    #[doc(hidden)]
     fn new(index: usize) -> Self;
+    #[doc(hidden)]
     fn index(&self) -> usize;
 }

lib/runtime/src/types.rs

@@ -101,23 +101,11 @@ pub struct GlobalDesc {
     pub ty: Type,
 }
 
-#[derive(Debug, Clone, PartialEq)]
-pub enum ImportedGlobalInit {
-    GetGlobal(ImportedGlobalIndex),
-    Import,
-}
-
-#[derive(Debug, Clone, PartialEq)]
-pub struct ImportedGlobal {
-    pub desc: GlobalDesc,
-    pub init: ImportedGlobalInit,
-}
-
 /// A wasm global.
 #[derive(Debug, Clone)]
 pub struct Global {
     pub desc: GlobalDesc,
-    pub init: Value,
+    pub init: Initializer,
 }
 
 /// A wasm memory.
@@ -174,10 +162,12 @@ macro_rules! define_map_index {
         #[derive(Debug, Copy, Clone, PartialEq, Eq)]
         pub struct $ty (u32);
         impl TypedIndex for $ty {
+            #[doc(hidden)]
             fn new(index: usize) -> Self {
                 $ty (index as _)
             }
 
+            #[doc(hidden)]
             fn index(&self) -> usize {
                 self.0 as usize
             }
@@ -247,10 +237,12 @@ define_local_or_import![
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct SigIndex(u32);
 impl TypedIndex for SigIndex {
+    #[doc(hidden)]
     fn new(index: usize) -> Self {
         SigIndex(index as _)
     }
 
+    #[doc(hidden)]
     fn index(&self) -> usize {
         self.0 as usize
     }
@@ -263,3 +255,22 @@ where
     Local(T::Local),
     Import(T::Import),
 }
+
+impl<T> LocalOrImport<T>
+where
+    T: LocalImport,
+{
+    pub fn local(self) -> Option<T::Local> {
+        match self {
+            LocalOrImport::Local(local) => Some(local),
+            LocalOrImport::Import(_) => None,
+        }
+    }
+
+    pub fn import(self) -> Option<T::Import> {
+        match self {
+            LocalOrImport::Import(import) => Some(import),
+            LocalOrImport::Local(_) => None,
+        }
+    }
+}

lib/runtime/src/vm.rs

@@ -127,6 +127,10 @@ impl LocalTable {
     pub fn offset_current_elements() -> u8 {
         1 * (mem::size_of::<usize>() as u8)
     }
+
+    pub fn size() -> u8 {
+        mem::size_of::<Self>() as u8
+    }
 }
 
 #[derive(Debug, Clone)]
@@ -146,6 +150,10 @@ impl ImportedTable {
     pub fn offset_vmctx() -> u8 {
         1 * (mem::size_of::<usize>() as u8)
     }
+
+    pub fn size() -> u8 {
+        mem::size_of::<Self>() as u8
+    }
 }
 
 /// Definition of a memory used by the VM.
@@ -166,6 +174,10 @@ impl LocalMemory {
     pub fn offset_size() -> u8 {
         1 * (mem::size_of::<usize>() as u8)
     }
+
+    pub fn size() -> u8 {
+        mem::size_of::<Self>() as u8
+    }
 }
 
 #[derive(Debug, Clone)]
@@ -184,6 +196,10 @@ impl ImportedMemory {
     pub fn offset_vmctx() -> u8 {
         1 * (mem::size_of::<usize>() as u8)
     }
+
+    pub fn size() -> u8 {
+        mem::size_of::<Self>() as u8
+    }
 }
 
 /// Definition of a global used by the VM.
@@ -257,6 +273,10 @@ impl Anyfunc {
     pub fn offset_sig_id() -> u8 {
         2 * (mem::size_of::<usize>() as u8)
     }
+
+    pub fn size() -> u8 {
+        mem::size_of::<Self>() as u8
+    }
 }
 
 #[cfg(test)]