ladybird/Userland/Libraries/LibWasm/AbstractMachine/AbstractMachine.h

679 lines
20 KiB
C++

/*
* Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Function.h>
#include <AK/HashMap.h>
#include <AK/HashTable.h>
#include <AK/OwnPtr.h>
#include <AK/Result.h>
#include <AK/StackInfo.h>
#include <AK/UFixedBigInt.h>
#include <LibWasm/Types.h>
// NOTE: Special case for Wasm::Result.
#include <LibJS/Runtime/Completion.h>
namespace Wasm {
class Configuration;
struct Interpreter;
struct InstantiationError {
ByteString error { "Unknown error" };
};
struct LinkError {
enum OtherErrors {
InvalidImportedModule,
};
Vector<ByteString> missing_imports;
Vector<OtherErrors> other_errors;
};
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(u64, FunctionAddress, Arithmetic, Comparison, Increment);
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(u64, ExternAddress, Arithmetic, Comparison, Increment);
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(u64, TableAddress, Arithmetic, Comparison, Increment);
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(u64, GlobalAddress, Arithmetic, Comparison, Increment);
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(u64, ElementAddress, Arithmetic, Comparison, Increment);
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(u64, DataAddress, Arithmetic, Comparison, Increment);
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(u64, MemoryAddress, Arithmetic, Comparison, Increment);
// FIXME: These should probably be made generic/virtual if/when we decide to do something more
// fancy than just a dumb interpreter.
class Reference {
public:
struct Null {
ValueType type;
};
struct Func {
FunctionAddress address;
};
struct Extern {
ExternAddress address;
};
using RefType = Variant<Null, Func, Extern>;
explicit Reference(RefType ref)
: m_ref(move(ref))
{
}
explicit Reference()
: m_ref(Reference::Null { ValueType(ValueType::Kind::FunctionReference) })
{
}
auto& ref() const { return m_ref; }
private:
RefType m_ref;
};
class Value {
public:
Value()
: m_value(0)
{
}
using AnyValueType = Variant<i32, i64, float, double, u128, Reference>;
explicit Value(AnyValueType value)
: m_value(move(value))
{
}
template<typename T>
requires(sizeof(T) == sizeof(u64)) explicit Value(ValueType type, T raw_value)
: m_value(0)
{
switch (type.kind()) {
case ValueType::Kind::ExternReference:
m_value = Reference { Reference::Extern { { bit_cast<u64>(raw_value) } } };
break;
case ValueType::Kind::FunctionReference:
m_value = Reference { Reference::Func { { bit_cast<u64>(raw_value) } } };
break;
case ValueType::Kind::I32:
m_value = static_cast<i32>(bit_cast<i64>(raw_value));
break;
case ValueType::Kind::I64:
m_value = static_cast<i64>(bit_cast<u64>(raw_value));
break;
case ValueType::Kind::F32:
m_value = static_cast<float>(bit_cast<double>(raw_value));
break;
case ValueType::Kind::F64:
m_value = bit_cast<double>(raw_value);
break;
case ValueType::Kind::V128:
m_value = u128(0ull, bit_cast<u64>(raw_value));
break;
default:
VERIFY_NOT_REACHED();
}
}
template<SameAs<u128> T>
explicit Value(T raw_value)
: m_value(raw_value)
{
}
ALWAYS_INLINE Value(Value const& value) = default;
ALWAYS_INLINE Value(Value&& value) = default;
ALWAYS_INLINE Value& operator=(Value&& value) = default;
ALWAYS_INLINE Value& operator=(Value const& value) = default;
template<typename T>
ALWAYS_INLINE Optional<T> to() const
{
Optional<T> result;
m_value.visit(
[&](auto value) {
if constexpr (IsSame<T, decltype(value)> || (!IsFloatingPoint<T> && IsSame<decltype(value), MakeSigned<T>>)) {
result = static_cast<T>(value);
} else if constexpr (!IsFloatingPoint<T> && IsConvertible<decltype(value), T>) {
// NOTE: No implicit vector <-> scalar conversion.
if constexpr (!IsSame<T, u128>) {
if (AK::is_within_range<T>(value))
result = static_cast<T>(value);
}
}
},
[&](u128 value) {
if constexpr (IsSame<T, u128>)
result = value;
},
[&](Reference const& value) {
if constexpr (IsSame<T, Reference>) {
result = value;
} else if constexpr (IsSame<T, Reference::Func>) {
if (auto ptr = value.ref().template get_pointer<Reference::Func>())
result = *ptr;
} else if constexpr (IsSame<T, Reference::Extern>) {
if (auto ptr = value.ref().template get_pointer<Reference::Extern>())
result = *ptr;
} else if constexpr (IsSame<T, Reference::Null>) {
if (auto ptr = value.ref().template get_pointer<Reference::Null>())
result = *ptr;
}
});
return result;
}
ValueType type() const
{
return ValueType(m_value.visit(
[](i32) { return ValueType::Kind::I32; },
[](i64) { return ValueType::Kind::I64; },
[](float) { return ValueType::Kind::F32; },
[](double) { return ValueType::Kind::F64; },
[](u128) { return ValueType::Kind::V128; },
[&](Reference const& type) {
return type.ref().visit(
[](Reference::Func const&) { return ValueType::Kind::FunctionReference; },
[](Reference::Null const& null_type) {
return null_type.type.kind();
},
[](Reference::Extern const&) { return ValueType::Kind::ExternReference; });
}));
}
auto& value() const { return m_value; }
private:
AnyValueType m_value;
};
struct Trap {
ByteString reason;
};
// A variant of Result that does not include external reasons for error (JS::Completion, for now).
class PureResult {
public:
explicit PureResult(Vector<Value> values)
: m_result(move(values))
{
}
PureResult(Trap trap)
: m_result(move(trap))
{
}
auto is_trap() const { return m_result.has<Trap>(); }
auto& values() const { return m_result.get<Vector<Value>>(); }
auto& values() { return m_result.get<Vector<Value>>(); }
auto& trap() const { return m_result.get<Trap>(); }
auto& trap() { return m_result.get<Trap>(); }
private:
friend class Result;
explicit PureResult(Variant<Vector<Value>, Trap>&& result)
: m_result(move(result))
{
}
Variant<Vector<Value>, Trap> m_result;
};
class Result {
public:
explicit Result(Vector<Value> values)
: m_result(move(values))
{
}
Result(Trap trap)
: m_result(move(trap))
{
}
Result(JS::Completion completion)
: m_result(move(completion))
{
VERIFY(m_result.get<JS::Completion>().is_abrupt());
}
Result(PureResult&& result)
: m_result(result.m_result.downcast<decltype(m_result)>())
{
}
auto is_trap() const { return m_result.has<Trap>(); }
auto is_completion() const { return m_result.has<JS::Completion>(); }
auto& values() const { return m_result.get<Vector<Value>>(); }
auto& values() { return m_result.get<Vector<Value>>(); }
auto& trap() const { return m_result.get<Trap>(); }
auto& trap() { return m_result.get<Trap>(); }
auto& completion() { return m_result.get<JS::Completion>(); }
auto& completion() const { return m_result.get<JS::Completion>(); }
PureResult assert_wasm_result() &&
{
VERIFY(!is_completion());
return PureResult(move(m_result).downcast<Vector<Value>, Trap>());
}
private:
Variant<Vector<Value>, Trap, JS::Completion> m_result;
};
using ExternValue = Variant<FunctionAddress, TableAddress, MemoryAddress, GlobalAddress>;
class ExportInstance {
public:
explicit ExportInstance(ByteString name, ExternValue value)
: m_name(move(name))
, m_value(move(value))
{
}
auto& name() const { return m_name; }
auto& value() const { return m_value; }
private:
ByteString m_name;
ExternValue m_value;
};
class ModuleInstance {
public:
explicit ModuleInstance(
Vector<FunctionType> types, Vector<FunctionAddress> function_addresses, Vector<TableAddress> table_addresses,
Vector<MemoryAddress> memory_addresses, Vector<GlobalAddress> global_addresses, Vector<DataAddress> data_addresses,
Vector<ExportInstance> exports)
: m_types(move(types))
, m_functions(move(function_addresses))
, m_tables(move(table_addresses))
, m_memories(move(memory_addresses))
, m_globals(move(global_addresses))
, m_datas(move(data_addresses))
, m_exports(move(exports))
{
}
ModuleInstance() = default;
auto& types() const { return m_types; }
auto& functions() const { return m_functions; }
auto& tables() const { return m_tables; }
auto& memories() const { return m_memories; }
auto& globals() const { return m_globals; }
auto& elements() const { return m_elements; }
auto& datas() const { return m_datas; }
auto& exports() const { return m_exports; }
auto& types() { return m_types; }
auto& functions() { return m_functions; }
auto& tables() { return m_tables; }
auto& memories() { return m_memories; }
auto& globals() { return m_globals; }
auto& elements() { return m_elements; }
auto& datas() { return m_datas; }
auto& exports() { return m_exports; }
private:
Vector<FunctionType> m_types;
Vector<FunctionAddress> m_functions;
Vector<TableAddress> m_tables;
Vector<MemoryAddress> m_memories;
Vector<GlobalAddress> m_globals;
Vector<ElementAddress> m_elements;
Vector<DataAddress> m_datas;
Vector<ExportInstance> m_exports;
};
class WasmFunction {
public:
explicit WasmFunction(FunctionType const& type, ModuleInstance const& module, Module::Function const& code)
: m_type(type)
, m_module(module)
, m_code(code)
{
}
auto& type() const { return m_type; }
auto& module() const { return m_module; }
auto& code() const { return m_code; }
private:
FunctionType m_type;
ModuleInstance const& m_module;
Module::Function const& m_code;
};
class HostFunction {
public:
explicit HostFunction(AK::Function<Result(Configuration&, Vector<Value>&)> function, FunctionType const& type, ByteString name)
: m_function(move(function))
, m_type(type)
, m_name(move(name))
{
}
auto& function() { return m_function; }
auto& type() const { return m_type; }
auto& name() const { return m_name; }
private:
AK::Function<Result(Configuration&, Vector<Value>&)> m_function;
FunctionType m_type;
ByteString m_name;
};
using FunctionInstance = Variant<WasmFunction, HostFunction>;
class TableInstance {
public:
explicit TableInstance(TableType const& type, Vector<Reference> elements)
: m_elements(move(elements))
, m_type(type)
{
}
auto& elements() const { return m_elements; }
auto& elements() { return m_elements; }
auto& type() const { return m_type; }
bool grow(u32 size_to_grow, Reference const& fill_value)
{
if (size_to_grow == 0)
return true;
size_t new_size = m_elements.size() + size_to_grow;
if (auto max = m_type.limits().max(); max.has_value()) {
if (max.value() < new_size)
return false;
}
if (new_size >= NumericLimits<u32>::max()) {
return false;
}
auto previous_size = m_elements.size();
if (m_elements.try_resize(new_size).is_error())
return false;
for (size_t i = previous_size; i < m_elements.size(); ++i)
m_elements[i] = fill_value;
return true;
}
private:
Vector<Reference> m_elements;
TableType m_type;
};
class MemoryInstance {
public:
static ErrorOr<MemoryInstance> create(MemoryType const& type)
{
MemoryInstance instance { type };
if (!instance.grow(type.limits().min() * Constants::page_size))
return Error::from_string_literal("Failed to grow to requested size");
return { move(instance) };
}
auto& type() const { return m_type; }
auto size() const { return m_size; }
auto& data() const { return m_data; }
auto& data() { return m_data; }
enum class InhibitGrowCallback {
No,
Yes,
};
bool grow(size_t size_to_grow, InhibitGrowCallback inhibit_callback = InhibitGrowCallback::No)
{
if (size_to_grow == 0)
return true;
u64 new_size = m_data.size() + size_to_grow;
// Can't grow past 2^16 pages.
if (new_size >= Constants::page_size * 65536)
return false;
if (auto max = m_type.limits().max(); max.has_value()) {
if (max.value() * Constants::page_size < new_size)
return false;
}
auto previous_size = m_size;
if (m_data.try_resize(new_size).is_error())
return false;
m_size = new_size;
// The spec requires that we zero out everything on grow
__builtin_memset(m_data.offset_pointer(previous_size), 0, size_to_grow);
// NOTE: This exists because wasm-js-api wants to execute code after a successful grow,
// See [this issue](https://github.com/WebAssembly/spec/issues/1635) for more details.
if (inhibit_callback == InhibitGrowCallback::No && successful_grow_hook)
successful_grow_hook();
return true;
}
Function<void()> successful_grow_hook;
private:
explicit MemoryInstance(MemoryType const& type)
: m_type(type)
{
}
MemoryType m_type;
size_t m_size { 0 };
ByteBuffer m_data;
};
class GlobalInstance {
public:
explicit GlobalInstance(Value value, bool is_mutable)
: m_mutable(is_mutable)
, m_value(move(value))
{
}
auto is_mutable() const { return m_mutable; }
auto& value() const { return m_value; }
GlobalType type() const { return { m_value.type(), is_mutable() }; }
void set_value(Value value)
{
VERIFY(is_mutable());
m_value = move(value);
}
private:
bool m_mutable { false };
Value m_value;
};
class DataInstance {
public:
explicit DataInstance(Vector<u8> data)
: m_data(move(data))
{
}
size_t size() const { return m_data.size(); }
Vector<u8>& data() { return m_data; }
Vector<u8> const& data() const { return m_data; }
private:
Vector<u8> m_data;
};
class ElementInstance {
public:
explicit ElementInstance(ValueType type, Vector<Reference> references)
: m_type(move(type))
, m_references(move(references))
{
}
auto& type() const { return m_type; }
auto& references() const { return m_references; }
private:
ValueType m_type;
Vector<Reference> m_references;
};
class Store {
public:
Store() = default;
Optional<FunctionAddress> allocate(ModuleInstance& module, Module::Function const& function);
Optional<FunctionAddress> allocate(HostFunction&&);
Optional<TableAddress> allocate(TableType const&);
Optional<MemoryAddress> allocate(MemoryType const&);
Optional<DataAddress> allocate_data(Vector<u8>);
Optional<GlobalAddress> allocate(GlobalType const&, Value);
Optional<ElementAddress> allocate(ValueType const&, Vector<Reference>);
FunctionInstance* get(FunctionAddress);
TableInstance* get(TableAddress);
MemoryInstance* get(MemoryAddress);
GlobalInstance* get(GlobalAddress);
DataInstance* get(DataAddress);
ElementInstance* get(ElementAddress);
private:
Vector<FunctionInstance> m_functions;
Vector<TableInstance> m_tables;
Vector<MemoryInstance> m_memories;
Vector<GlobalInstance> m_globals;
Vector<ElementInstance> m_elements;
Vector<DataInstance> m_datas;
};
class Label {
public:
explicit Label(size_t arity, InstructionPointer continuation)
: m_arity(arity)
, m_continuation(continuation)
{
}
auto continuation() const { return m_continuation; }
auto arity() const { return m_arity; }
private:
size_t m_arity { 0 };
InstructionPointer m_continuation { 0 };
};
class Frame {
public:
explicit Frame(ModuleInstance const& module, Vector<Value> locals, Expression const& expression, size_t arity)
: m_module(module)
, m_locals(move(locals))
, m_expression(expression)
, m_arity(arity)
{
}
auto& module() const { return m_module; }
auto& locals() const { return m_locals; }
auto& locals() { return m_locals; }
auto& expression() const { return m_expression; }
auto arity() const { return m_arity; }
private:
ModuleInstance const& m_module;
Vector<Value> m_locals;
Expression const& m_expression;
size_t m_arity { 0 };
};
class Stack {
public:
using EntryType = Variant<Value, Label, Frame>;
Stack() = default;
[[nodiscard]] ALWAYS_INLINE bool is_empty() const { return m_data.is_empty(); }
ALWAYS_INLINE void push(EntryType entry) { m_data.append(move(entry)); }
ALWAYS_INLINE auto pop() { return m_data.take_last(); }
ALWAYS_INLINE auto& peek() const { return m_data.last(); }
ALWAYS_INLINE auto& peek() { return m_data.last(); }
ALWAYS_INLINE auto size() const { return m_data.size(); }
ALWAYS_INLINE auto& entries() const { return m_data; }
ALWAYS_INLINE auto& entries() { return m_data; }
private:
Vector<EntryType, 1024> m_data;
};
using InstantiationResult = AK::ErrorOr<NonnullOwnPtr<ModuleInstance>, InstantiationError>;
class AbstractMachine {
public:
explicit AbstractMachine() = default;
// Validate a module; permanently sets the module's validity status.
ErrorOr<void, ValidationError> validate(Module&);
// Load and instantiate a module, and link it into this interpreter.
InstantiationResult instantiate(Module const&, Vector<ExternValue>);
Result invoke(FunctionAddress, Vector<Value>);
Result invoke(Interpreter&, FunctionAddress, Vector<Value>);
auto& store() const { return m_store; }
auto& store() { return m_store; }
void enable_instruction_count_limit() { m_should_limit_instruction_count = true; }
private:
Optional<InstantiationError> allocate_all_initial_phase(Module const&, ModuleInstance&, Vector<ExternValue>&, Vector<Value>& global_values, Vector<FunctionAddress>& own_functions);
Optional<InstantiationError> allocate_all_final_phase(Module const&, ModuleInstance&, Vector<Vector<Reference>>& elements);
Store m_store;
StackInfo m_stack_info;
bool m_should_limit_instruction_count { false };
};
class Linker {
public:
struct Name {
ByteString module;
ByteString name;
ImportSection::Import::ImportDesc type;
};
explicit Linker(Module const& module)
: m_module(module)
{
}
// Link a module, the import 'module name' is ignored with this.
void link(ModuleInstance const&);
// Link a bunch of qualified values, also matches 'module name'.
void link(HashMap<Name, ExternValue> const&);
auto& unresolved_imports()
{
populate();
return m_unresolved_imports;
}
AK::ErrorOr<Vector<ExternValue>, LinkError> finish();
private:
void populate();
Module const& m_module;
HashMap<Name, ExternValue> m_resolved_imports;
HashTable<Name> m_unresolved_imports;
Vector<Name> m_ordered_imports;
Optional<LinkError> m_error;
};
}
template<>
struct AK::Traits<Wasm::Linker::Name> : public AK::DefaultTraits<Wasm::Linker::Name> {
static constexpr bool is_trivial() { return false; }
static unsigned hash(Wasm::Linker::Name const& entry) { return pair_int_hash(entry.module.hash(), entry.name.hash()); }
static bool equals(Wasm::Linker::Name const& a, Wasm::Linker::Name const& b) { return a.name == b.name && a.module == b.module; }
};