use crate::export::Export;
use crate::imports::Imports;
use crate::jit_int::GdbJitImageRegistration;
use crate::memory::LinearMemory;
use crate::mmap::Mmap;
use crate::signalhandlers::{wasmtime_init_eager, wasmtime_init_finish};
use crate::table::Table;
use crate::traphandlers::wasmtime_call;
use crate::vmcontext::{
VMBuiltinFunctionsArray, VMCallerCheckedAnyfunc, VMContext, VMFunctionBody, VMFunctionImport,
VMGlobalDefinition, VMGlobalImport, VMMemoryDefinition, VMMemoryImport, VMSharedSignatureIndex,
VMTableDefinition, VMTableImport,
};
use crate::{HashMap, HashSet};
use alloc::borrow::ToOwned;
use alloc::boxed::Box;
use alloc::rc::Rc;
use alloc::string::{String, ToString};
use core::any::Any;
use core::borrow::Borrow;
use core::cell::RefCell;
use core::convert::TryFrom;
use core::{mem, ptr, slice};
use cranelift_entity::{BoxedSlice, EntityRef, PrimaryMap};
use cranelift_wasm::{
DefinedFuncIndex, DefinedGlobalIndex, DefinedMemoryIndex, DefinedTableIndex, FuncIndex,
GlobalIndex, GlobalInit, MemoryIndex, SignatureIndex, TableIndex,
};
use memoffset::offset_of;
use more_asserts::assert_lt;
use thiserror::Error;
use wasmtime_environ::{DataInitializer, Module, TableElements, VMOffsets};
fn signature_id(
vmctx: &VMContext,
offsets: &VMOffsets,
index: SignatureIndex,
) -> VMSharedSignatureIndex {
#[allow(clippy::cast_ptr_alignment)]
unsafe {
let ptr = (vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_vmshared_signature_id(index)).unwrap());
*(ptr as *const VMSharedSignatureIndex)
}
}
fn imported_function<'vmctx>(
vmctx: &'vmctx VMContext,
offsets: &VMOffsets,
index: FuncIndex,
) -> &'vmctx VMFunctionImport {
#[allow(clippy::cast_ptr_alignment)]
unsafe {
let ptr = (vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_vmfunction_import(index)).unwrap());
&*(ptr as *const VMFunctionImport)
}
}
fn imported_table<'vmctx>(
vmctx: &'vmctx VMContext,
offsets: &VMOffsets,
index: TableIndex,
) -> &'vmctx VMTableImport {
#[allow(clippy::cast_ptr_alignment)]
unsafe {
let ptr = (vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_vmtable_import(index)).unwrap());
&*(ptr as *const VMTableImport)
}
}
fn imported_memory<'vmctx>(
vmctx: &'vmctx VMContext,
offsets: &VMOffsets,
index: MemoryIndex,
) -> &'vmctx VMMemoryImport {
#[allow(clippy::cast_ptr_alignment)]
unsafe {
let ptr = (vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_vmmemory_import(index)).unwrap());
&*(ptr as *const VMMemoryImport)
}
}
fn imported_global<'vmctx>(
vmctx: &'vmctx VMContext,
offsets: &VMOffsets,
index: GlobalIndex,
) -> &'vmctx VMGlobalImport {
unsafe {
let ptr = (vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_vmglobal_import(index)).unwrap());
#[allow(clippy::cast_ptr_alignment)]
&*(ptr as *const VMGlobalImport)
}
}
fn table<'vmctx>(
vmctx: &'vmctx VMContext,
offsets: &VMOffsets,
index: DefinedTableIndex,
) -> &'vmctx VMTableDefinition {
unsafe {
let ptr = (vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_vmtable_definition(index)).unwrap());
#[allow(clippy::cast_ptr_alignment)]
&*(ptr as *const VMTableDefinition)
}
}
fn table_mut<'vmctx>(
vmctx: &'vmctx mut VMContext,
offsets: &VMOffsets,
index: DefinedTableIndex,
) -> &'vmctx mut VMTableDefinition {
unsafe {
let ptr = (vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(offsets.vmctx_vmtable_definition(index)).unwrap());
#[allow(clippy::cast_ptr_alignment)]
&mut *(ptr as *mut VMTableDefinition)
}
}
fn memory<'vmctx>(
vmctx: &'vmctx VMContext,
offsets: &VMOffsets,
index: DefinedMemoryIndex,
) -> &'vmctx VMMemoryDefinition {
unsafe {
let ptr = (vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_vmmemory_definition(index)).unwrap());
#[allow(clippy::cast_ptr_alignment)]
&*(ptr as *const VMMemoryDefinition)
}
}
fn memory_mut<'vmctx>(
vmctx: &'vmctx mut VMContext,
offsets: &VMOffsets,
index: DefinedMemoryIndex,
) -> &'vmctx mut VMMemoryDefinition {
unsafe {
let ptr = (vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(offsets.vmctx_vmmemory_definition(index)).unwrap());
#[allow(clippy::cast_ptr_alignment)]
&mut *(ptr as *mut VMMemoryDefinition)
}
}
fn global<'vmctx>(
vmctx: &'vmctx VMContext,
offsets: &VMOffsets,
index: DefinedGlobalIndex,
) -> &'vmctx VMGlobalDefinition {
unsafe {
let ptr = (vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_vmglobal_definition(index)).unwrap());
#[allow(clippy::cast_ptr_alignment)]
&*(ptr as *const VMGlobalDefinition)
}
}
fn global_mut<'vmctx>(
vmctx: &'vmctx mut VMContext,
offsets: &VMOffsets,
index: DefinedGlobalIndex,
) -> &'vmctx mut VMGlobalDefinition {
unsafe {
let ptr = (vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(offsets.vmctx_vmglobal_definition(index)).unwrap());
#[allow(clippy::cast_ptr_alignment)]
&mut *(ptr as *mut VMGlobalDefinition)
}
}
#[repr(C)]
pub(crate) struct Instance {
refcount: usize,
dependencies: HashSet<InstanceHandle>,
mmap: Mmap,
module: Rc<Module>,
offsets: VMOffsets,
global_exports: Rc<RefCell<HashMap<String, Option<Export>>>>,
memories: BoxedSlice<DefinedMemoryIndex, LinearMemory>,
tables: BoxedSlice<DefinedTableIndex, Table>,
finished_functions: BoxedSlice<DefinedFuncIndex, *const VMFunctionBody>,
host_state: Box<dyn Any>,
dbg_jit_registration: Option<Rc<GdbJitImageRegistration>>,
vmctx: VMContext,
}
#[allow(clippy::cast_ptr_alignment)]
impl Instance {
#[allow(dead_code)]
fn signature_id(&self, index: SignatureIndex) -> VMSharedSignatureIndex {
signature_id(&self.vmctx, &self.offsets, index)
}
fn signature_ids_ptr(&mut self) -> *mut VMSharedSignatureIndex {
unsafe {
(&mut self.vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(self.offsets.vmctx_signature_ids_begin()).unwrap())
as *mut VMSharedSignatureIndex
}
}
fn imported_function(&self, index: FuncIndex) -> &VMFunctionImport {
imported_function(&self.vmctx, &self.offsets, index)
}
fn imported_functions_ptr(&mut self) -> *mut VMFunctionImport {
unsafe {
(&mut self.vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(self.offsets.vmctx_imported_functions_begin()).unwrap())
as *mut VMFunctionImport
}
}
#[allow(dead_code)]
fn imported_table(&self, index: TableIndex) -> &VMTableImport {
imported_table(&self.vmctx, &self.offsets, index)
}
fn imported_tables_ptr(&mut self) -> *mut VMTableImport {
unsafe {
(&mut self.vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(self.offsets.vmctx_imported_tables_begin()).unwrap())
as *mut VMTableImport
}
}
fn imported_memory(&self, index: MemoryIndex) -> &VMMemoryImport {
imported_memory(&self.vmctx, &self.offsets, index)
}
fn imported_memories_ptr(&mut self) -> *mut VMMemoryImport {
unsafe {
(&mut self.vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(self.offsets.vmctx_imported_memories_begin()).unwrap())
as *mut VMMemoryImport
}
}
fn imported_global(&self, index: GlobalIndex) -> &VMGlobalImport {
imported_global(&self.vmctx, &self.offsets, index)
}
fn imported_globals_ptr(&mut self) -> *mut VMGlobalImport {
unsafe {
(&mut self.vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(self.offsets.vmctx_imported_globals_begin()).unwrap())
as *mut VMGlobalImport
}
}
#[allow(dead_code)]
fn table(&self, index: DefinedTableIndex) -> &VMTableDefinition {
table(&self.vmctx, &self.offsets, index)
}
#[allow(dead_code)]
fn table_mut(&mut self, index: DefinedTableIndex) -> &mut VMTableDefinition {
table_mut(&mut self.vmctx, &self.offsets, index)
}
fn tables_ptr(&mut self) -> *mut VMTableDefinition {
unsafe {
(&mut self.vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(self.offsets.vmctx_tables_begin()).unwrap())
as *mut VMTableDefinition
}
}
fn memory(&self, index: DefinedMemoryIndex) -> &VMMemoryDefinition {
memory(&self.vmctx, &self.offsets, index)
}
fn memory_mut(&mut self, index: DefinedMemoryIndex) -> &mut VMMemoryDefinition {
memory_mut(&mut self.vmctx, &self.offsets, index)
}
fn memories_ptr(&mut self) -> *mut VMMemoryDefinition {
unsafe {
(&mut self.vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(self.offsets.vmctx_memories_begin()).unwrap())
as *mut VMMemoryDefinition
}
}
#[allow(dead_code)]
fn global(&self, index: DefinedGlobalIndex) -> &VMGlobalDefinition {
global(&self.vmctx, &self.offsets, index)
}
fn global_mut(&mut self, index: DefinedGlobalIndex) -> &mut VMGlobalDefinition {
global_mut(&mut self.vmctx, &self.offsets, index)
}
fn globals_ptr(&mut self) -> *mut VMGlobalDefinition {
unsafe {
(&mut self.vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(self.offsets.vmctx_globals_begin()).unwrap())
as *mut VMGlobalDefinition
}
}
fn builtin_functions_ptr(&mut self) -> *mut VMBuiltinFunctionsArray {
unsafe {
(&mut self.vmctx as *mut VMContext as *mut u8)
.add(usize::try_from(self.offsets.vmctx_builtin_functions_begin()).unwrap())
as *mut VMBuiltinFunctionsArray
}
}
pub fn vmctx(&self) -> &VMContext {
&self.vmctx
}
pub fn vmctx_ptr(&self) -> *const VMContext {
self.vmctx()
}
pub fn vmctx_mut(&mut self) -> &mut VMContext {
&mut self.vmctx
}
pub fn vmctx_mut_ptr(&mut self) -> *mut VMContext {
self.vmctx_mut()
}
pub fn lookup(&mut self, field: &str) -> Option<Export> {
let export = if let Some(export) = self.module.exports.get(field) {
export.clone()
} else {
return None;
};
Some(self.lookup_by_declaration(&export))
}
pub unsafe fn lookup_immutable(&self, field: &str) -> Option<Export> {
#[allow(clippy::cast_ref_to_mut)]
let temporary_mut = &mut *(self as *const Self as *mut Self);
temporary_mut.lookup(field)
}
pub fn lookup_by_declaration(&mut self, export: &wasmtime_environ::Export) -> Export {
lookup_by_declaration(
&self.module,
&mut self.vmctx,
&self.offsets,
&self.finished_functions,
export,
)
}
pub unsafe fn lookup_immutable_by_declaration(
&self,
export: &wasmtime_environ::Export,
) -> Export {
#[allow(clippy::cast_ref_to_mut)]
let temporary_mut = &mut *(self as *const Self as *mut Self);
temporary_mut.lookup_by_declaration(export)
}
pub fn exports(&self) -> indexmap::map::Iter<String, wasmtime_environ::Export> {
self.module.exports.iter()
}
pub fn host_state(&mut self) -> &mut dyn Any {
&mut *self.host_state
}
fn invoke_function(&mut self, index: FuncIndex) -> Result<(), InstantiationError> {
let (callee_address, callee_vmctx) = match self.module.defined_func_index(index) {
Some(defined_index) => {
let body = *self
.finished_functions
.get(defined_index)
.expect("function index is out of bounds");
(body, self.vmctx_mut() as *mut VMContext)
}
None => {
assert_lt!(index.index(), self.module.imported_funcs.len());
let import = self.imported_function(index);
(import.body, import.vmctx)
}
};
unsafe { wasmtime_call(callee_vmctx, callee_address) }
.map_err(InstantiationError::StartTrap)
}
fn invoke_start_function(&mut self) -> Result<(), InstantiationError> {
if let Some(start_index) = self.module.start_func {
self.invoke_function(start_index)
} else if let Some(start_export) = self.module.exports.get("_start") {
match *start_export {
wasmtime_environ::Export::Function(func_index) => {
let sig = &self.module.signatures[self.module.functions[func_index]];
if sig.params.len() == 1 && sig.returns.is_empty() {
self.invoke_function(func_index)
} else {
Ok(())
}
}
_ => Ok(()),
}
} else if let Some(main_export) = self.module.exports.get("main") {
match *main_export {
wasmtime_environ::Export::Function(func_index) => {
let sig = &self.module.signatures[self.module.functions[func_index]];
if sig.params.len() == 1 && sig.returns.is_empty() {
self.invoke_function(func_index)
} else {
Ok(())
}
}
_ => Ok(()),
}
} else {
Ok(())
}
}
pub(crate) fn vmctx_offset() -> isize {
offset_of!(Self, vmctx) as isize
}
pub(crate) fn table_index(&self, table: &VMTableDefinition) -> DefinedTableIndex {
let offsets = &self.offsets;
let begin = unsafe {
(&self.vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_tables_begin()).unwrap())
} as *const VMTableDefinition;
let end: *const VMTableDefinition = table;
let index = DefinedTableIndex::new(
(end as usize - begin as usize) / mem::size_of::<VMTableDefinition>(),
);
assert_lt!(index.index(), self.tables.len());
index
}
pub(crate) fn memory_index(&self, memory: &VMMemoryDefinition) -> DefinedMemoryIndex {
let offsets = &self.offsets;
let begin = unsafe {
(&self.vmctx as *const VMContext as *const u8)
.add(usize::try_from(offsets.vmctx_memories_begin()).unwrap())
} as *const VMMemoryDefinition;
let end: *const VMMemoryDefinition = memory;
let index = DefinedMemoryIndex::new(
(end as usize - begin as usize) / mem::size_of::<VMMemoryDefinition>(),
);
assert_lt!(index.index(), self.memories.len());
index
}
pub(crate) fn needs_signal_handlers(&self) -> bool {
self.memories
.values()
.any(|memory| memory.needs_signal_handlers)
}
pub(crate) fn memory_grow(
&mut self,
memory_index: DefinedMemoryIndex,
delta: u32,
) -> Option<u32> {
let result = self
.memories
.get_mut(memory_index)
.unwrap_or_else(|| panic!("no memory for index {}", memory_index.index()))
.grow(delta);
*self.memory_mut(memory_index) = self.memories[memory_index].vmmemory();
result
}
pub(crate) unsafe fn imported_memory_grow(
&mut self,
memory_index: MemoryIndex,
delta: u32,
) -> Option<u32> {
let import = self.imported_memory(memory_index);
let foreign_instance = (&mut *import.vmctx).instance();
let foreign_memory = &mut *import.from;
let foreign_index = foreign_instance.memory_index(foreign_memory);
foreign_instance.memory_grow(foreign_index, delta)
}
pub(crate) fn memory_size(&mut self, memory_index: DefinedMemoryIndex) -> u32 {
self.memories
.get(memory_index)
.unwrap_or_else(|| panic!("no memory for index {}", memory_index.index()))
.size()
}
pub(crate) unsafe fn imported_memory_size(&mut self, memory_index: MemoryIndex) -> u32 {
let import = self.imported_memory(memory_index);
let foreign_instance = (&mut *import.vmctx).instance();
let foreign_memory = &mut *import.from;
let foreign_index = foreign_instance.memory_index(foreign_memory);
foreign_instance.memory_size(foreign_index)
}
pub(crate) fn lookup_global_export(&self, field: &str) -> Option<Export> {
let cell: &RefCell<HashMap<alloc::string::String, core::option::Option<Export>>> =
self.global_exports.borrow();
let map: &mut HashMap<alloc::string::String, core::option::Option<Export>> =
&mut cell.borrow_mut();
if let Some(Some(export)) = map.get(field) {
return Some(export.clone());
}
None
}
pub(crate) fn table_grow(&mut self, table_index: DefinedTableIndex, delta: u32) -> Option<u32> {
let result = self
.tables
.get_mut(table_index)
.unwrap_or_else(|| panic!("no table for index {}", table_index.index()))
.grow(delta);
*self.table_mut(table_index) = self.tables[table_index].vmtable();
result
}
pub(crate) fn table_get(
&self,
table_index: DefinedTableIndex,
index: u32,
) -> Option<&VMCallerCheckedAnyfunc> {
self.tables
.get(table_index)
.unwrap_or_else(|| panic!("no table for index {}", table_index.index()))
.get(index)
}
pub(crate) fn table_get_mut(
&mut self,
table_index: DefinedTableIndex,
index: u32,
) -> Option<&mut VMCallerCheckedAnyfunc> {
self.tables
.get_mut(table_index)
.unwrap_or_else(|| panic!("no table for index {}", table_index.index()))
.get_mut(index)
}
}
#[derive(Hash, PartialEq, Eq)]
pub struct InstanceHandle {
instance: *mut Instance,
}
impl InstanceHandle {
pub fn new(
module: Rc<Module>,
global_exports: Rc<RefCell<HashMap<String, Option<Export>>>>,
finished_functions: BoxedSlice<DefinedFuncIndex, *const VMFunctionBody>,
imports: Imports,
data_initializers: &[DataInitializer<'_>],
vmshared_signatures: BoxedSlice<SignatureIndex, VMSharedSignatureIndex>,
dbg_jit_registration: Option<Rc<GdbJitImageRegistration>>,
host_state: Box<dyn Any>,
) -> Result<Self, InstantiationError> {
let mut tables = create_tables(&module);
let mut memories = create_memories(&module)?;
let vmctx_tables = tables
.values_mut()
.map(Table::vmtable)
.collect::<PrimaryMap<DefinedTableIndex, _>>()
.into_boxed_slice();
let vmctx_memories = memories
.values_mut()
.map(LinearMemory::vmmemory)
.collect::<PrimaryMap<DefinedMemoryIndex, _>>()
.into_boxed_slice();
let vmctx_globals = create_globals(&module);
let offsets = VMOffsets::new(mem::size_of::<*const u8>() as u8, &module);
let mut instance_mmap = Mmap::with_at_least(
mem::size_of::<Instance>()
.checked_add(usize::try_from(offsets.size_of_vmctx()).unwrap())
.unwrap(),
)
.map_err(InstantiationError::Resource)?;
let instance = {
#[allow(clippy::cast_ptr_alignment)]
let instance_ptr = instance_mmap.as_mut_ptr() as *mut Instance;
let instance = Instance {
refcount: 1,
dependencies: imports.dependencies,
mmap: instance_mmap,
module,
global_exports,
offsets,
memories,
tables,
finished_functions,
dbg_jit_registration,
host_state,
vmctx: VMContext {},
};
unsafe {
ptr::write(instance_ptr, instance);
&mut *instance_ptr
}
};
unsafe {
ptr::copy(
vmshared_signatures.values().as_slice().as_ptr(),
instance.signature_ids_ptr() as *mut VMSharedSignatureIndex,
vmshared_signatures.len(),
);
ptr::copy(
imports.functions.values().as_slice().as_ptr(),
instance.imported_functions_ptr() as *mut VMFunctionImport,
imports.functions.len(),
);
ptr::copy(
imports.tables.values().as_slice().as_ptr(),
instance.imported_tables_ptr() as *mut VMTableImport,
imports.tables.len(),
);
ptr::copy(
imports.memories.values().as_slice().as_ptr(),
instance.imported_memories_ptr() as *mut VMMemoryImport,
imports.memories.len(),
);
ptr::copy(
imports.globals.values().as_slice().as_ptr(),
instance.imported_globals_ptr() as *mut VMGlobalImport,
imports.globals.len(),
);
ptr::copy(
vmctx_tables.values().as_slice().as_ptr(),
instance.tables_ptr() as *mut VMTableDefinition,
vmctx_tables.len(),
);
ptr::copy(
vmctx_memories.values().as_slice().as_ptr(),
instance.memories_ptr() as *mut VMMemoryDefinition,
vmctx_memories.len(),
);
ptr::copy(
vmctx_globals.values().as_slice().as_ptr(),
instance.globals_ptr() as *mut VMGlobalDefinition,
vmctx_globals.len(),
);
ptr::write(
instance.builtin_functions_ptr() as *mut VMBuiltinFunctionsArray,
VMBuiltinFunctionsArray::initialized(),
);
}
check_table_init_bounds(instance)?;
check_memory_init_bounds(instance, data_initializers)?;
initialize_tables(instance)?;
initialize_memories(instance, data_initializers)?;
initialize_globals(instance);
for (field, decl) in &instance.module.exports {
use crate::hash_map::Entry::*;
let cell: &RefCell<HashMap<alloc::string::String, core::option::Option<Export>>> =
instance.global_exports.borrow();
let map: &mut HashMap<alloc::string::String, core::option::Option<Export>> =
&mut cell.borrow_mut();
match map.entry(field.to_string()) {
Vacant(entry) => {
entry.insert(Some(lookup_by_declaration(
&instance.module,
&mut instance.vmctx,
&instance.offsets,
&instance.finished_functions,
&decl,
)));
}
Occupied(ref mut entry) => *entry.get_mut() = None,
}
}
wasmtime_init_eager();
wasmtime_init_finish(instance.vmctx_mut());
instance.invoke_start_function()?;
Ok(Self { instance })
}
pub unsafe fn from_vmctx(vmctx: *mut VMContext) -> Self {
let instance = (&mut *vmctx).instance();
instance.refcount += 1;
Self { instance }
}
pub fn vmctx(&self) -> &VMContext {
self.instance().vmctx()
}
pub fn vmctx_ptr(&self) -> *const VMContext {
self.instance().vmctx_ptr()
}
pub fn module(&self) -> Rc<Module> {
self.instance().module.clone()
}
pub fn module_ref(&self) -> &Module {
&self.instance().module
}
pub fn vmctx_mut(&mut self) -> &mut VMContext {
self.instance_mut().vmctx_mut()
}
pub fn vmctx_mut_ptr(&mut self) -> *mut VMContext {
self.instance_mut().vmctx_mut_ptr()
}
pub fn lookup(&mut self, field: &str) -> Option<Export> {
self.instance_mut().lookup(field)
}
pub unsafe fn lookup_immutable(&self, field: &str) -> Option<Export> {
self.instance().lookup_immutable(field)
}
pub fn lookup_by_declaration(&mut self, export: &wasmtime_environ::Export) -> Export {
self.instance_mut().lookup_by_declaration(export)
}
pub unsafe fn lookup_immutable_by_declaration(
&self,
export: &wasmtime_environ::Export,
) -> Export {
self.instance().lookup_immutable_by_declaration(export)
}
pub fn exports(&self) -> indexmap::map::Iter<String, wasmtime_environ::Export> {
self.instance().exports()
}
pub fn host_state(&mut self) -> &mut dyn Any {
self.instance_mut().host_state()
}
pub fn memory_index(&self, memory: &VMMemoryDefinition) -> DefinedMemoryIndex {
self.instance().memory_index(memory)
}
pub fn memory_grow(&mut self, memory_index: DefinedMemoryIndex, delta: u32) -> Option<u32> {
self.instance_mut().memory_grow(memory_index, delta)
}
pub fn table_index(&self, table: &VMTableDefinition) -> DefinedTableIndex {
self.instance().table_index(table)
}
pub fn table_grow(&mut self, table_index: DefinedTableIndex, delta: u32) -> Option<u32> {
self.instance_mut().table_grow(table_index, delta)
}
pub fn table_get(
&self,
table_index: DefinedTableIndex,
index: u32,
) -> Option<&VMCallerCheckedAnyfunc> {
self.instance().table_get(table_index, index)
}
pub fn table_get_mut(
&mut self,
table_index: DefinedTableIndex,
index: u32,
) -> Option<&mut VMCallerCheckedAnyfunc> {
self.instance_mut().table_get_mut(table_index, index)
}
}
impl InstanceHandle {
fn instance(&self) -> &Instance {
unsafe { &*(self.instance as *const Instance) }
}
fn instance_mut(&mut self) -> &mut Instance {
unsafe { &mut *(self.instance as *mut Instance) }
}
}
impl Clone for InstanceHandle {
fn clone(&self) -> Self {
unsafe { &mut *(self.instance as *mut Instance) }.refcount += 1;
Self {
instance: self.instance,
}
}
}
impl Drop for InstanceHandle {
fn drop(&mut self) {
let instance = self.instance_mut();
instance.refcount -= 1;
if instance.refcount == 0 {
let mmap = mem::replace(&mut instance.mmap, Mmap::new());
unsafe { ptr::drop_in_place(instance) };
mem::drop(mmap);
}
}
}
fn lookup_by_declaration(
module: &Module,
vmctx: &mut VMContext,
offsets: &VMOffsets,
finished_functions: &BoxedSlice<DefinedFuncIndex, *const VMFunctionBody>,
export: &wasmtime_environ::Export,
) -> Export {
match export {
wasmtime_environ::Export::Function(index) => {
let signature = module.signatures[module.functions[*index]].clone();
let (address, vmctx) = if let Some(def_index) = module.defined_func_index(*index) {
(finished_functions[def_index], vmctx as *mut VMContext)
} else {
let import = imported_function(vmctx, offsets, *index);
(import.body, import.vmctx)
};
Export::Function {
address,
signature,
vmctx,
}
}
wasmtime_environ::Export::Table(index) => {
let (definition, vmctx) = if let Some(def_index) = module.defined_table_index(*index) {
(
table_mut(vmctx, offsets, def_index) as *mut VMTableDefinition,
vmctx as *mut VMContext,
)
} else {
let import = imported_table(vmctx, offsets, *index);
(import.from, import.vmctx)
};
Export::Table {
definition,
vmctx,
table: module.table_plans[*index].clone(),
}
}
wasmtime_environ::Export::Memory(index) => {
let (definition, vmctx) = if let Some(def_index) = module.defined_memory_index(*index) {
(
memory_mut(vmctx, offsets, def_index) as *mut VMMemoryDefinition,
vmctx as *mut VMContext,
)
} else {
let import = imported_memory(vmctx, offsets, *index);
(import.from, import.vmctx)
};
Export::Memory {
definition,
vmctx,
memory: module.memory_plans[*index].clone(),
}
}
wasmtime_environ::Export::Global(index) => Export::Global {
definition: if let Some(def_index) = module.defined_global_index(*index) {
global_mut(vmctx, offsets, def_index)
} else {
imported_global(vmctx, offsets, *index).from
},
vmctx,
global: module.globals[*index],
},
}
}
fn check_table_init_bounds(instance: &mut Instance) -> Result<(), InstantiationError> {
let module = Rc::clone(&instance.module);
for init in &module.table_elements {
let start = get_table_init_start(init, instance);
let slice = get_table_slice(
init,
&instance.module,
&mut instance.tables,
&instance.vmctx,
&instance.offsets,
);
if slice.get_mut(start..start + init.elements.len()).is_none() {
return Err(InstantiationError::Link(LinkError(
"elements segment does not fit".to_owned(),
)));
}
}
Ok(())
}
fn get_memory_init_start(init: &DataInitializer<'_>, instance: &mut Instance) -> usize {
let mut start = init.location.offset;
if let Some(base) = init.location.base {
let global = if let Some(def_index) = instance.module.defined_global_index(base) {
instance.global_mut(def_index)
} else {
instance.imported_global(base).from
};
start += usize::try_from(*unsafe { (*global).as_u32() }).unwrap();
}
start
}
fn get_memory_slice<'instance>(
init: &DataInitializer<'_>,
instance: &'instance mut Instance,
) -> &'instance mut [u8] {
let memory = if let Some(defined_memory_index) = instance
.module
.defined_memory_index(init.location.memory_index)
{
instance.memory(defined_memory_index)
} else {
let import = instance.imported_memory(init.location.memory_index);
let foreign_instance = unsafe { (&mut *(import).vmctx).instance() };
let foreign_memory = unsafe { &mut *(import).from };
let foreign_index = foreign_instance.memory_index(foreign_memory);
foreign_instance.memory(foreign_index)
};
unsafe { slice::from_raw_parts_mut(memory.base, memory.current_length) }
}
fn check_memory_init_bounds(
instance: &mut Instance,
data_initializers: &[DataInitializer<'_>],
) -> Result<(), InstantiationError> {
for init in data_initializers {
let start = get_memory_init_start(init, instance);
let mem_slice = get_memory_slice(init, instance);
if mem_slice.get_mut(start..start + init.data.len()).is_none() {
return Err(InstantiationError::Link(LinkError(
"data segment does not fit".to_owned(),
)));
}
}
Ok(())
}
fn create_tables(module: &Module) -> BoxedSlice<DefinedTableIndex, Table> {
let num_imports = module.imported_tables.len();
let mut tables: PrimaryMap<DefinedTableIndex, _> =
PrimaryMap::with_capacity(module.table_plans.len() - num_imports);
for table in &module.table_plans.values().as_slice()[num_imports..] {
tables.push(Table::new(table));
}
tables.into_boxed_slice()
}
fn get_table_init_start(init: &TableElements, instance: &mut Instance) -> usize {
let mut start = init.offset;
if let Some(base) = init.base {
let global = if let Some(def_index) = instance.module.defined_global_index(base) {
instance.global_mut(def_index)
} else {
instance.imported_global(base).from
};
start += usize::try_from(*unsafe { (*global).as_u32() }).unwrap();
}
start
}
fn get_table_slice<'instance>(
init: &TableElements,
module: &Module,
tables: &'instance mut BoxedSlice<DefinedTableIndex, Table>,
vmctx: &VMContext,
offsets: &VMOffsets,
) -> &'instance mut [VMCallerCheckedAnyfunc] {
if let Some(defined_table_index) = module.defined_table_index(init.table_index) {
tables[defined_table_index].as_mut()
} else {
let import = imported_table(vmctx, offsets, init.table_index);
let foreign_instance = unsafe { (&mut *(import).vmctx).instance() };
let foreign_table = unsafe { &mut *(import).from };
let foreign_index = foreign_instance.table_index(foreign_table);
foreign_instance.tables[foreign_index].as_mut()
}
}
fn initialize_tables(instance: &mut Instance) -> Result<(), InstantiationError> {
let vmctx: *mut VMContext = instance.vmctx_mut();
let module = Rc::clone(&instance.module);
for init in &module.table_elements {
let start = get_table_init_start(init, instance);
let slice = get_table_slice(
init,
&instance.module,
&mut instance.tables,
&instance.vmctx,
&instance.offsets,
);
let subslice = &mut slice[start..start + init.elements.len()];
for (i, func_idx) in init.elements.iter().enumerate() {
let callee_sig = instance.module.functions[*func_idx];
let (callee_ptr, callee_vmctx) =
if let Some(index) = instance.module.defined_func_index(*func_idx) {
(instance.finished_functions[index], vmctx)
} else {
let imported_func =
imported_function(&instance.vmctx, &instance.offsets, *func_idx);
(imported_func.body, imported_func.vmctx)
};
let type_index = signature_id(&instance.vmctx, &instance.offsets, callee_sig);
subslice[i] = VMCallerCheckedAnyfunc {
func_ptr: callee_ptr,
type_index,
vmctx: callee_vmctx,
};
}
}
Ok(())
}
fn create_memories(
module: &Module,
) -> Result<BoxedSlice<DefinedMemoryIndex, LinearMemory>, InstantiationError> {
let num_imports = module.imported_memories.len();
let mut memories: PrimaryMap<DefinedMemoryIndex, _> =
PrimaryMap::with_capacity(module.memory_plans.len() - num_imports);
for plan in &module.memory_plans.values().as_slice()[num_imports..] {
memories.push(LinearMemory::new(plan).map_err(InstantiationError::Resource)?);
}
Ok(memories.into_boxed_slice())
}
fn initialize_memories(
instance: &mut Instance,
data_initializers: &[DataInitializer<'_>],
) -> Result<(), InstantiationError> {
for init in data_initializers {
let start = get_memory_init_start(init, instance);
let mem_slice = get_memory_slice(init, instance);
let to_init = &mut mem_slice[start..start + init.data.len()];
to_init.copy_from_slice(init.data);
}
Ok(())
}
fn create_globals(module: &Module) -> BoxedSlice<DefinedGlobalIndex, VMGlobalDefinition> {
let num_imports = module.imported_globals.len();
let mut vmctx_globals = PrimaryMap::with_capacity(module.globals.len() - num_imports);
for _ in &module.globals.values().as_slice()[num_imports..] {
vmctx_globals.push(VMGlobalDefinition::new());
}
vmctx_globals.into_boxed_slice()
}
fn initialize_globals(instance: &mut Instance) {
let module = Rc::clone(&instance.module);
let num_imports = module.imported_globals.len();
for (index, global) in module.globals.iter().skip(num_imports) {
let def_index = module.defined_global_index(index).unwrap();
let to: *mut VMGlobalDefinition = instance.global_mut(def_index);
match global.initializer {
GlobalInit::I32Const(x) => *unsafe { (*to).as_i32_mut() } = x,
GlobalInit::I64Const(x) => *unsafe { (*to).as_i64_mut() } = x,
GlobalInit::F32Const(x) => *unsafe { (*to).as_f32_bits_mut() } = x,
GlobalInit::F64Const(x) => *unsafe { (*to).as_f64_bits_mut() } = x,
GlobalInit::V128Const(x) => *unsafe { (*to).as_u128_bits_mut() } = x.0,
GlobalInit::GetGlobal(x) => {
let from = if let Some(def_x) = module.defined_global_index(x) {
instance.global_mut(def_x)
} else {
instance.imported_global(x).from
};
unsafe { *to = *from };
}
GlobalInit::Import => panic!("locally-defined global initialized as import"),
}
}
}
#[derive(Error, Debug)]
#[error("Link error: {0}")]
pub struct LinkError(pub String);
#[derive(Error, Debug)]
pub enum InstantiationError {
#[error("Insufficient resources: {0}")]
Resource(String),
#[error("Failed to link module")]
Link(#[from] LinkError),
#[error("Trap occurred while invoking start function: {0}")]
StartTrap(String),
}