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Initial reorg.

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This is largely the same as #305, but updated for the current tree.
This commit is contained in:
Dan Gohman
2019-11-07 17:11:06 -08:00
parent 2c69546a24
commit 22641de629
351 changed files with 52 additions and 52 deletions
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615
crates/runtime/src/vmcontext.rs Normal file
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//! This file declares `VMContext` and several related structs which contain
//! fields that compiled wasm code accesses directly.
use crate::instance::Instance;
use core::any::Any;
use core::{ptr, u32};
use wasmtime_environ::BuiltinFunctionIndex;
/// An imported function.
#[derive(Debug, Copy, Clone)]
#[repr(C)]
pub struct VMFunctionImport {
/// A pointer to the imported function body.
pub body: *const VMFunctionBody,
/// A pointer to the `VMContext` that owns the function.
pub vmctx: *mut VMContext,
}
#[cfg(test)]
mod test_vmfunction_import {
use super::VMFunctionImport;
use core::mem::size_of;
use wasmtime_environ::{Module, VMOffsets};
#[test]
fn check_vmfunction_import_offsets() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMFunctionImport>(),
usize::from(offsets.size_of_vmfunction_import())
);
assert_eq!(
offset_of!(VMFunctionImport, body),
usize::from(offsets.vmfunction_import_body())
);
assert_eq!(
offset_of!(VMFunctionImport, vmctx),
usize::from(offsets.vmfunction_import_vmctx())
);
}
}
/// A placeholder byte-sized type which is just used to provide some amount of type
/// safety when dealing with pointers to JIT-compiled function bodies. Note that it's
/// deliberately not Copy, as we shouldn't be carelessly copying function body bytes
/// around.
#[repr(C)]
pub struct VMFunctionBody(u8);
#[cfg(test)]
mod test_vmfunction_body {
use super::VMFunctionBody;
use core::mem::size_of;
#[test]
fn check_vmfunction_body_offsets() {
assert_eq!(size_of::<VMFunctionBody>(), 1);
}
}
/// The fields compiled code needs to access to utilize a WebAssembly table
/// imported from another instance.
#[derive(Debug, Copy, Clone)]
#[repr(C)]
pub struct VMTableImport {
/// A pointer to the imported table description.
pub from: *mut VMTableDefinition,
/// A pointer to the `VMContext` that owns the table description.
pub vmctx: *mut VMContext,
}
#[cfg(test)]
mod test_vmtable_import {
use super::VMTableImport;
use core::mem::size_of;
use wasmtime_environ::{Module, VMOffsets};
#[test]
fn check_vmtable_import_offsets() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMTableImport>(),
usize::from(offsets.size_of_vmtable_import())
);
assert_eq!(
offset_of!(VMTableImport, from),
usize::from(offsets.vmtable_import_from())
);
assert_eq!(
offset_of!(VMTableImport, vmctx),
usize::from(offsets.vmtable_import_vmctx())
);
}
}
/// The fields compiled code needs to access to utilize a WebAssembly linear
/// memory imported from another instance.
#[derive(Debug, Copy, Clone)]
#[repr(C)]
pub struct VMMemoryImport {
/// A pointer to the imported memory description.
pub from: *mut VMMemoryDefinition,
/// A pointer to the `VMContext` that owns the memory description.
pub vmctx: *mut VMContext,
}
#[cfg(test)]
mod test_vmmemory_import {
use super::VMMemoryImport;
use core::mem::size_of;
use wasmtime_environ::{Module, VMOffsets};
#[test]
fn check_vmmemory_import_offsets() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMMemoryImport>(),
usize::from(offsets.size_of_vmmemory_import())
);
assert_eq!(
offset_of!(VMMemoryImport, from),
usize::from(offsets.vmmemory_import_from())
);
assert_eq!(
offset_of!(VMMemoryImport, vmctx),
usize::from(offsets.vmmemory_import_vmctx())
);
}
}
/// The fields compiled code needs to access to utilize a WebAssembly global
/// variable imported from another instance.
#[derive(Debug, Copy, Clone)]
#[repr(C)]
pub struct VMGlobalImport {
/// A pointer to the imported global variable description.
pub from: *mut VMGlobalDefinition,
}
#[cfg(test)]
mod test_vmglobal_import {
use super::VMGlobalImport;
use core::mem::size_of;
use wasmtime_environ::{Module, VMOffsets};
#[test]
fn check_vmglobal_import_offsets() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMGlobalImport>(),
usize::from(offsets.size_of_vmglobal_import())
);
assert_eq!(
offset_of!(VMGlobalImport, from),
usize::from(offsets.vmglobal_import_from())
);
}
}
/// The fields compiled code needs to access to utilize a WebAssembly linear
/// memory defined within the instance, namely the start address and the
/// size in bytes.
#[derive(Debug, Copy, Clone)]
#[repr(C)]
pub struct VMMemoryDefinition {
/// The start address.
pub base: *mut u8,
/// The current logical size of this linear memory in bytes.
pub current_length: usize,
}
#[cfg(test)]
mod test_vmmemory_definition {
use super::VMMemoryDefinition;
use core::mem::size_of;
use wasmtime_environ::{Module, VMOffsets};
#[test]
fn check_vmmemory_definition_offsets() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMMemoryDefinition>(),
usize::from(offsets.size_of_vmmemory_definition())
);
assert_eq!(
offset_of!(VMMemoryDefinition, base),
usize::from(offsets.vmmemory_definition_base())
);
assert_eq!(
offset_of!(VMMemoryDefinition, current_length),
usize::from(offsets.vmmemory_definition_current_length())
);
/* TODO: Assert that the size of `current_length` matches.
assert_eq!(
size_of::<VMMemoryDefinition::current_length>(),
usize::from(offsets.size_of_vmmemory_definition_current_length())
);
*/
}
}
/// The fields compiled code needs to access to utilize a WebAssembly table
/// defined within the instance.
#[derive(Debug, Copy, Clone)]
#[repr(C)]
pub struct VMTableDefinition {
/// Pointer to the table data.
pub base: *mut u8,
/// The current number of elements in the table.
pub current_elements: u32,
}
#[cfg(test)]
mod test_vmtable_definition {
use super::VMTableDefinition;
use core::mem::size_of;
use wasmtime_environ::{Module, VMOffsets};
#[test]
fn check_vmtable_definition_offsets() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMTableDefinition>(),
usize::from(offsets.size_of_vmtable_definition())
);
assert_eq!(
offset_of!(VMTableDefinition, base),
usize::from(offsets.vmtable_definition_base())
);
assert_eq!(
offset_of!(VMTableDefinition, current_elements),
usize::from(offsets.vmtable_definition_current_elements())
);
}
}
/// The storage for a WebAssembly global defined within the instance.
///
/// TODO: Pack the globals more densely, rather than using the same size
/// for every type.
#[derive(Debug, Copy, Clone)]
#[repr(C, align(16))]
pub struct VMGlobalDefinition {
storage: [u8; 16],
// If more elements are added here, remember to add offset_of tests below!
}
#[cfg(test)]
mod test_vmglobal_definition {
use super::VMGlobalDefinition;
use core::mem::{align_of, size_of};
use wasmtime_environ::{Module, VMOffsets};
#[test]
fn check_vmglobal_definition_alignment() {
assert!(align_of::<VMGlobalDefinition>() >= align_of::<i32>());
assert!(align_of::<VMGlobalDefinition>() >= align_of::<i64>());
assert!(align_of::<VMGlobalDefinition>() >= align_of::<f32>());
assert!(align_of::<VMGlobalDefinition>() >= align_of::<f64>());
assert!(align_of::<VMGlobalDefinition>() >= align_of::<[u8; 16]>());
}
#[test]
fn check_vmglobal_definition_offsets() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMGlobalDefinition>(),
usize::from(offsets.size_of_vmglobal_definition())
);
}
#[test]
fn check_vmglobal_begins_aligned() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(offsets.vmctx_globals_begin() % 16, 0);
}
}
impl VMGlobalDefinition {
/// Construct a `VMGlobalDefinition`.
pub fn new() -> Self {
Self { storage: [0; 16] }
}
/// Return a reference to the value as an i32.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_i32(&self) -> &i32 {
&*(self.storage.as_ref().as_ptr() as *const i32)
}
/// Return a mutable reference to the value as an i32.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_i32_mut(&mut self) -> &mut i32 {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut i32)
}
/// Return a reference to the value as a u32.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_u32(&self) -> &u32 {
&*(self.storage.as_ref().as_ptr() as *const u32)
}
/// Return a mutable reference to the value as an u32.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_u32_mut(&mut self) -> &mut u32 {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut u32)
}
/// Return a reference to the value as an i64.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_i64(&self) -> &i64 {
&*(self.storage.as_ref().as_ptr() as *const i64)
}
/// Return a mutable reference to the value as an i64.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_i64_mut(&mut self) -> &mut i64 {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut i64)
}
/// Return a reference to the value as an u64.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_u64(&self) -> &u64 {
&*(self.storage.as_ref().as_ptr() as *const u64)
}
/// Return a mutable reference to the value as an u64.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_u64_mut(&mut self) -> &mut u64 {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut u64)
}
/// Return a reference to the value as an f32.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_f32(&self) -> &f32 {
&*(self.storage.as_ref().as_ptr() as *const f32)
}
/// Return a mutable reference to the value as an f32.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_f32_mut(&mut self) -> &mut f32 {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut f32)
}
/// Return a reference to the value as f32 bits.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_f32_bits(&self) -> &u32 {
&*(self.storage.as_ref().as_ptr() as *const u32)
}
/// Return a mutable reference to the value as f32 bits.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_f32_bits_mut(&mut self) -> &mut u32 {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut u32)
}
/// Return a reference to the value as an f64.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_f64(&self) -> &f64 {
&*(self.storage.as_ref().as_ptr() as *const f64)
}
/// Return a mutable reference to the value as an f64.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_f64_mut(&mut self) -> &mut f64 {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut f64)
}
/// Return a reference to the value as f64 bits.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_f64_bits(&self) -> &u64 {
&*(self.storage.as_ref().as_ptr() as *const u64)
}
/// Return a mutable reference to the value as f64 bits.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_f64_bits_mut(&mut self) -> &mut u64 {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut u64)
}
/// Return a reference to the value as an u128.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_u128(&self) -> &u128 {
&*(self.storage.as_ref().as_ptr() as *const u128)
}
/// Return a mutable reference to the value as an u128.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_u128_mut(&mut self) -> &mut u128 {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut u128)
}
/// Return a reference to the value as u128 bits.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_u128_bits(&self) -> &[u8; 16] {
&*(self.storage.as_ref().as_ptr() as *const [u8; 16])
}
/// Return a mutable reference to the value as u128 bits.
#[allow(clippy::cast_ptr_alignment)]
pub unsafe fn as_u128_bits_mut(&mut self) -> &mut [u8; 16] {
&mut *(self.storage.as_mut().as_mut_ptr() as *mut [u8; 16])
}
}
/// An index into the shared signature registry, usable for checking signatures
/// at indirect calls.
#[repr(C)]
#[derive(Debug, Eq, PartialEq, Clone, Copy, Hash)]
pub struct VMSharedSignatureIndex(u32);
#[cfg(test)]
mod test_vmshared_signature_index {
use super::VMSharedSignatureIndex;
use core::mem::size_of;
use wasmtime_environ::{Module, TargetSharedSignatureIndex, VMOffsets};
#[test]
fn check_vmshared_signature_index() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMSharedSignatureIndex>(),
usize::from(offsets.size_of_vmshared_signature_index())
);
}
#[test]
fn check_target_shared_signature_index() {
assert_eq!(
size_of::<VMSharedSignatureIndex>(),
size_of::<TargetSharedSignatureIndex>()
);
}
}
impl VMSharedSignatureIndex {
/// Create a new `VMSharedSignatureIndex`.
pub fn new(value: u32) -> Self {
Self(value)
}
}
impl Default for VMSharedSignatureIndex {
fn default() -> Self {
Self::new(u32::MAX)
}
}
/// The VM caller-checked "anyfunc" record, for caller-side signature checking.
/// It consists of the actual function pointer and a signature id to be checked
/// by the caller.
#[derive(Debug, Clone)]
#[repr(C)]
pub struct VMCallerCheckedAnyfunc {
/// Function body.
pub func_ptr: *const VMFunctionBody,
/// Function signature id.
pub type_index: VMSharedSignatureIndex,
/// Function `VMContext`.
pub vmctx: *mut VMContext,
// If more elements are added here, remember to add offset_of tests below!
}
#[cfg(test)]
mod test_vmcaller_checked_anyfunc {
use super::VMCallerCheckedAnyfunc;
use core::mem::size_of;
use wasmtime_environ::{Module, VMOffsets};
#[test]
fn check_vmcaller_checked_anyfunc_offsets() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMCallerCheckedAnyfunc>(),
usize::from(offsets.size_of_vmcaller_checked_anyfunc())
);
assert_eq!(
offset_of!(VMCallerCheckedAnyfunc, func_ptr),
usize::from(offsets.vmcaller_checked_anyfunc_func_ptr())
);
assert_eq!(
offset_of!(VMCallerCheckedAnyfunc, type_index),
usize::from(offsets.vmcaller_checked_anyfunc_type_index())
);
assert_eq!(
offset_of!(VMCallerCheckedAnyfunc, vmctx),
usize::from(offsets.vmcaller_checked_anyfunc_vmctx())
);
}
}
impl Default for VMCallerCheckedAnyfunc {
fn default() -> Self {
Self {
func_ptr: ptr::null_mut(),
type_index: Default::default(),
vmctx: ptr::null_mut(),
}
}
}
/// An array that stores addresses of builtin functions. We translate code
/// to use indirect calls. This way, we don't have to patch the code.
#[repr(C)]
pub struct VMBuiltinFunctionsArray {
ptrs: [usize; Self::len()],
}
impl VMBuiltinFunctionsArray {
pub const fn len() -> usize {
BuiltinFunctionIndex::builtin_functions_total_number() as usize
}
pub fn initialized() -> Self {
use crate::libcalls::*;
let mut ptrs = [0; Self::len()];
ptrs[BuiltinFunctionIndex::get_memory32_grow_index().index() as usize] =
wasmtime_memory32_grow as usize;
ptrs[BuiltinFunctionIndex::get_imported_memory32_grow_index().index() as usize] =
wasmtime_imported_memory32_grow as usize;
ptrs[BuiltinFunctionIndex::get_memory32_size_index().index() as usize] =
wasmtime_memory32_size as usize;
ptrs[BuiltinFunctionIndex::get_imported_memory32_size_index().index() as usize] =
wasmtime_imported_memory32_size as usize;
Self { ptrs }
}
}
/// The storage for a WebAssembly invocation argument
///
/// TODO: These could be packed more densely, rather than using the same size for every type.
#[derive(Debug, Copy, Clone)]
#[repr(C, align(16))]
pub struct VMInvokeArgument([u8; 16]);
#[cfg(test)]
mod test_vm_invoke_argument {
use super::VMInvokeArgument;
use core::mem::{align_of, size_of};
use wasmtime_environ::{Module, VMOffsets};
#[test]
fn check_vm_invoke_argument_alignment() {
assert_eq!(align_of::<VMInvokeArgument>(), 16);
}
#[test]
fn check_vmglobal_definition_offsets() {
let module = Module::new();
let offsets = VMOffsets::new(size_of::<*mut u8>() as u8, &module);
assert_eq!(
size_of::<VMInvokeArgument>(),
usize::from(offsets.size_of_vmglobal_definition())
);
}
}
impl VMInvokeArgument {
/// Create a new invocation argument filled with zeroes
pub fn new() -> Self {
Self([0; 16])
}
}
/// The VM "context", which is pointed to by the `vmctx` arg in Cranelift.
/// This has information about globals, memories, tables, and other runtime
/// state associated with the current instance.
///
/// The struct here is empty, as the sizes of these fields are dynamic, and
/// we can't describe them in Rust's type system. Sufficient memory is
/// allocated at runtime.
///
/// TODO: We could move the globals into the `vmctx` allocation too.
#[derive(Debug)]
#[repr(C)]
pub struct VMContext {}
impl VMContext {
/// Return a mutable reference to the associated `Instance`.
///
/// This is unsafe because it doesn't work on just any `VMContext`, it must
/// be a `VMContext` allocated as part of an `Instance`.
#[allow(clippy::cast_ptr_alignment)]
pub(crate) unsafe fn instance(&mut self) -> &mut Instance {
&mut *((self as *mut Self as *mut u8).offset(-Instance::vmctx_offset()) as *mut Instance)
}
/// Return a mutable reference to the host state associated with this `Instance`.
///
/// This is unsafe because it doesn't work on just any `VMContext`, it must
/// be a `VMContext` allocated as part of an `Instance`.
pub unsafe fn host_state(&mut self) -> &mut dyn Any {
self.instance().host_state()
}
/// Lookup an export in the global exports namespace.
pub unsafe fn lookup_global_export(&mut self, field: &str) -> Option<crate::export::Export> {
self.instance().lookup_global_export(field)
}
}