ladybird/Userland/Libraries/LibJS/Bytecode/Op.h

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/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
* Copyright (c) 2021, Gunnar Beutner <gbeutner@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibCrypto/BigInt/SignedBigInteger.h>
#include <LibJS/Bytecode/Instruction.h>
#include <LibJS/Bytecode/Label.h>
#include <LibJS/Bytecode/Register.h>
#include <LibJS/Bytecode/StringTable.h>
#include <LibJS/Heap/Cell.h>
#include <LibJS/Runtime/ScopeObject.h>
#include <LibJS/Runtime/Value.h>
namespace JS::Bytecode::Op {
class Load final : public Instruction {
public:
explicit Load(Register src)
: Instruction(Type::Load)
, m_src(src)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
Register m_src;
};
class LoadImmediate final : public Instruction {
public:
explicit LoadImmediate(Value value)
: Instruction(Type::LoadImmediate)
, m_value(value)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
Value m_value;
};
class Store final : public Instruction {
public:
explicit Store(Register dst)
: Instruction(Type::Store)
, m_dst(dst)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
Register m_dst;
};
#define JS_ENUMERATE_COMMON_BINARY_OPS(O) \
O(Add, add) \
O(Sub, sub) \
O(Mul, mul) \
O(Div, div) \
O(Exp, exp) \
O(Mod, mod) \
O(In, in) \
O(InstanceOf, instance_of) \
O(GreaterThan, greater_than) \
O(GreaterThanEquals, greater_than_equals) \
O(LessThan, less_than) \
O(LessThanEquals, less_than_equals) \
O(AbstractInequals, abstract_inequals) \
O(AbstractEquals, abstract_equals) \
O(TypedInequals, typed_inequals) \
O(TypedEquals, typed_equals) \
O(BitwiseAnd, bitwise_and) \
O(BitwiseOr, bitwise_or) \
O(BitwiseXor, bitwise_xor) \
O(LeftShift, left_shift) \
O(RightShift, right_shift) \
O(UnsignedRightShift, unsigned_right_shift)
#define JS_DECLARE_COMMON_BINARY_OP(OpTitleCase, op_snake_case) \
class OpTitleCase final : public Instruction { \
public: \
explicit OpTitleCase(Register lhs_reg) \
: Instruction(Type::OpTitleCase) \
, m_lhs_reg(lhs_reg) \
{ \
} \
\
void execute_impl(Bytecode::Interpreter&) const; \
String to_string_impl(Bytecode::Executable const&) const; \
\
private: \
Register m_lhs_reg; \
};
JS_ENUMERATE_COMMON_BINARY_OPS(JS_DECLARE_COMMON_BINARY_OP)
#undef JS_DECLARE_COMMON_BINARY_OP
#define JS_ENUMERATE_COMMON_UNARY_OPS(O) \
O(BitwiseNot, bitwise_not) \
O(Not, not_) \
O(UnaryPlus, unary_plus) \
O(UnaryMinus, unary_minus) \
O(Typeof, typeof_)
#define JS_DECLARE_COMMON_UNARY_OP(OpTitleCase, op_snake_case) \
class OpTitleCase final : public Instruction { \
public: \
OpTitleCase() \
: Instruction(Type::OpTitleCase) \
{ \
} \
\
void execute_impl(Bytecode::Interpreter&) const; \
String to_string_impl(Bytecode::Executable const&) const; \
};
JS_ENUMERATE_COMMON_UNARY_OPS(JS_DECLARE_COMMON_UNARY_OP)
#undef JS_DECLARE_COMMON_UNARY_OP
class NewString final : public Instruction {
public:
explicit NewString(StringTableIndex string)
: Instruction(Type::NewString)
, m_string(string)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
StringTableIndex m_string;
};
class NewObject final : public Instruction {
public:
NewObject()
: Instruction(Type::NewObject)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
};
class NewBigInt final : public Instruction {
public:
explicit NewBigInt(Crypto::SignedBigInteger bigint)
: Instruction(Type::NewBigInt)
, m_bigint(move(bigint))
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
Crypto::SignedBigInteger m_bigint;
};
// NOTE: This instruction is variable-width depending on the number of elements!
class NewArray final : public Instruction {
public:
explicit NewArray(Vector<Register> const& elements)
: Instruction(Type::NewArray)
, m_element_count(elements.size())
{
for (size_t i = 0; i < m_element_count; ++i)
m_elements[i] = elements[i];
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
size_t length_impl() const { return sizeof(*this) + sizeof(Register) * m_element_count; }
private:
size_t m_element_count { 0 };
Register m_elements[];
};
class ConcatString final : public Instruction {
public:
explicit ConcatString(Register lhs)
: Instruction(Type::ConcatString)
, m_lhs(lhs)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
Register m_lhs;
};
class SetVariable final : public Instruction {
public:
explicit SetVariable(StringTableIndex identifier)
: Instruction(Type::SetVariable)
, m_identifier(identifier)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
StringTableIndex m_identifier;
};
class GetVariable final : public Instruction {
public:
explicit GetVariable(StringTableIndex identifier)
: Instruction(Type::GetVariable)
, m_identifier(identifier)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
StringTableIndex m_identifier;
};
class GetById final : public Instruction {
public:
explicit GetById(StringTableIndex property)
: Instruction(Type::GetById)
, m_property(property)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
StringTableIndex m_property;
};
class PutById final : public Instruction {
public:
explicit PutById(Register base, StringTableIndex property)
: Instruction(Type::PutById)
, m_base(base)
, m_property(property)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
Register m_base;
StringTableIndex m_property;
};
class GetByValue final : public Instruction {
public:
explicit GetByValue(Register base)
: Instruction(Type::GetByValue)
, m_base(base)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
Register m_base;
};
class PutByValue final : public Instruction {
public:
PutByValue(Register base, Register property)
: Instruction(Type::PutByValue)
, m_base(base)
, m_property(property)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
Register m_base;
Register m_property;
};
class Jump : public Instruction {
public:
constexpr static bool IsTerminator = true;
explicit Jump(Type type, Optional<Label> taken_target = {}, Optional<Label> nontaken_target = {})
: Instruction(type)
, m_true_target(move(taken_target))
, m_false_target(move(nontaken_target))
{
}
explicit Jump(Optional<Label> taken_target = {}, Optional<Label> nontaken_target = {})
: Instruction(Type::Jump)
, m_true_target(move(taken_target))
, m_false_target(move(nontaken_target))
{
}
void set_targets(Optional<Label> true_target, Optional<Label> false_target)
{
m_true_target = move(true_target);
m_false_target = move(false_target);
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
protected:
Optional<Label> m_true_target;
Optional<Label> m_false_target;
};
class JumpConditional final : public Jump {
public:
explicit JumpConditional(Optional<Label> true_target = {}, Optional<Label> false_target = {})
: Jump(Type::JumpConditional, move(true_target), move(false_target))
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
};
class JumpNullish final : public Jump {
public:
explicit JumpNullish(Optional<Label> true_target = {}, Optional<Label> false_target = {})
: Jump(Type::JumpNullish, move(true_target), move(false_target))
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
};
// NOTE: This instruction is variable-width depending on the number of arguments!
class Call final : public Instruction {
public:
enum class CallType {
Call,
Construct,
};
Call(CallType type, Register callee, Register this_value, Vector<Register> const& arguments)
: Instruction(Type::Call)
, m_callee(callee)
, m_this_value(this_value)
, m_type(type)
, m_argument_count(arguments.size())
{
for (size_t i = 0; i < m_argument_count; ++i)
m_arguments[i] = arguments[i];
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
size_t length_impl() const { return sizeof(*this) + sizeof(Register) * m_argument_count; }
private:
Register m_callee;
Register m_this_value;
CallType m_type;
size_t m_argument_count { 0 };
Register m_arguments[];
};
class NewFunction final : public Instruction {
public:
explicit NewFunction(FunctionNode const& function_node)
: Instruction(Type::NewFunction)
, m_function_node(function_node)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
FunctionNode const& m_function_node;
};
class Return final : public Instruction {
public:
constexpr static bool IsTerminator = true;
Return()
: Instruction(Type::Return)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
};
class Increment final : public Instruction {
public:
Increment()
: Instruction(Type::Increment)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
};
class Decrement final : public Instruction {
public:
Decrement()
: Instruction(Type::Decrement)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
};
class Throw final : public Instruction {
public:
constexpr static bool IsTerminator = true;
Throw()
: Instruction(Type::Throw)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
};
LibJS: Implement bytecode generation for try..catch..finally EnterUnwindContext pushes an unwind context (exception handler and/or finalizer) onto a stack. LeaveUnwindContext pops the unwind context from that stack. Upon return to the interpreter loop we check whether the VM has an exception pending. If no unwind context is available we return from the loop. If an exception handler is available we clear the VM's exception, put the exception value into the accumulator register, clear the unwind context's handler and jump to the handler. If no handler is available but a finalizer is available we save the exception value + metadata (for later use by ContinuePendingUnwind), clear the VM's exception, pop the unwind context and jump to the finalizer. ContinuePendingUnwind checks whether a saved exception is available. If no saved exception is available it jumps to the resume label. Otherwise it stores the exception into the VM. The Jump after LeaveUnwindContext could be integrated into the LeaveUnwindContext instruction. I've kept them separate for now to make the bytecode more readable. > try { 1; throw "x" } catch (e) { 2 } finally { 3 }; 4 1: [ 0] EnterScope [ 10] EnterUnwindContext handler:@4 finalizer:@3 [ 38] EnterScope [ 48] LoadImmediate 1 [ 60] NewString 1 ("x") [ 70] Throw <for non-terminated blocks: insert LeaveUnwindContext + Jump @3 here> 2: [ 0] LoadImmediate 4 3: [ 0] EnterScope [ 10] LoadImmediate 3 [ 28] ContinuePendingUnwind resume:@2 4: [ 0] SetVariable 0 (e) [ 10] EnterScope [ 20] LoadImmediate 2 [ 38] LeaveUnwindContext [ 3c] Jump @3 String Table: 0: e 1: x
2021-06-10 15:04:38 +02:00
class EnterUnwindContext final : public Instruction {
public:
constexpr static bool IsTerminator = true;
EnterUnwindContext(Label entry_point, Optional<Label> handler_target, Optional<Label> finalizer_target)
LibJS: Implement bytecode generation for try..catch..finally EnterUnwindContext pushes an unwind context (exception handler and/or finalizer) onto a stack. LeaveUnwindContext pops the unwind context from that stack. Upon return to the interpreter loop we check whether the VM has an exception pending. If no unwind context is available we return from the loop. If an exception handler is available we clear the VM's exception, put the exception value into the accumulator register, clear the unwind context's handler and jump to the handler. If no handler is available but a finalizer is available we save the exception value + metadata (for later use by ContinuePendingUnwind), clear the VM's exception, pop the unwind context and jump to the finalizer. ContinuePendingUnwind checks whether a saved exception is available. If no saved exception is available it jumps to the resume label. Otherwise it stores the exception into the VM. The Jump after LeaveUnwindContext could be integrated into the LeaveUnwindContext instruction. I've kept them separate for now to make the bytecode more readable. > try { 1; throw "x" } catch (e) { 2 } finally { 3 }; 4 1: [ 0] EnterScope [ 10] EnterUnwindContext handler:@4 finalizer:@3 [ 38] EnterScope [ 48] LoadImmediate 1 [ 60] NewString 1 ("x") [ 70] Throw <for non-terminated blocks: insert LeaveUnwindContext + Jump @3 here> 2: [ 0] LoadImmediate 4 3: [ 0] EnterScope [ 10] LoadImmediate 3 [ 28] ContinuePendingUnwind resume:@2 4: [ 0] SetVariable 0 (e) [ 10] EnterScope [ 20] LoadImmediate 2 [ 38] LeaveUnwindContext [ 3c] Jump @3 String Table: 0: e 1: x
2021-06-10 15:04:38 +02:00
: Instruction(Type::EnterUnwindContext)
, m_entry_point(move(entry_point))
, m_handler_target(move(handler_target))
, m_finalizer_target(move(finalizer_target))
LibJS: Implement bytecode generation for try..catch..finally EnterUnwindContext pushes an unwind context (exception handler and/or finalizer) onto a stack. LeaveUnwindContext pops the unwind context from that stack. Upon return to the interpreter loop we check whether the VM has an exception pending. If no unwind context is available we return from the loop. If an exception handler is available we clear the VM's exception, put the exception value into the accumulator register, clear the unwind context's handler and jump to the handler. If no handler is available but a finalizer is available we save the exception value + metadata (for later use by ContinuePendingUnwind), clear the VM's exception, pop the unwind context and jump to the finalizer. ContinuePendingUnwind checks whether a saved exception is available. If no saved exception is available it jumps to the resume label. Otherwise it stores the exception into the VM. The Jump after LeaveUnwindContext could be integrated into the LeaveUnwindContext instruction. I've kept them separate for now to make the bytecode more readable. > try { 1; throw "x" } catch (e) { 2 } finally { 3 }; 4 1: [ 0] EnterScope [ 10] EnterUnwindContext handler:@4 finalizer:@3 [ 38] EnterScope [ 48] LoadImmediate 1 [ 60] NewString 1 ("x") [ 70] Throw <for non-terminated blocks: insert LeaveUnwindContext + Jump @3 here> 2: [ 0] LoadImmediate 4 3: [ 0] EnterScope [ 10] LoadImmediate 3 [ 28] ContinuePendingUnwind resume:@2 4: [ 0] SetVariable 0 (e) [ 10] EnterScope [ 20] LoadImmediate 2 [ 38] LeaveUnwindContext [ 3c] Jump @3 String Table: 0: e 1: x
2021-06-10 15:04:38 +02:00
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
LibJS: Implement bytecode generation for try..catch..finally EnterUnwindContext pushes an unwind context (exception handler and/or finalizer) onto a stack. LeaveUnwindContext pops the unwind context from that stack. Upon return to the interpreter loop we check whether the VM has an exception pending. If no unwind context is available we return from the loop. If an exception handler is available we clear the VM's exception, put the exception value into the accumulator register, clear the unwind context's handler and jump to the handler. If no handler is available but a finalizer is available we save the exception value + metadata (for later use by ContinuePendingUnwind), clear the VM's exception, pop the unwind context and jump to the finalizer. ContinuePendingUnwind checks whether a saved exception is available. If no saved exception is available it jumps to the resume label. Otherwise it stores the exception into the VM. The Jump after LeaveUnwindContext could be integrated into the LeaveUnwindContext instruction. I've kept them separate for now to make the bytecode more readable. > try { 1; throw "x" } catch (e) { 2 } finally { 3 }; 4 1: [ 0] EnterScope [ 10] EnterUnwindContext handler:@4 finalizer:@3 [ 38] EnterScope [ 48] LoadImmediate 1 [ 60] NewString 1 ("x") [ 70] Throw <for non-terminated blocks: insert LeaveUnwindContext + Jump @3 here> 2: [ 0] LoadImmediate 4 3: [ 0] EnterScope [ 10] LoadImmediate 3 [ 28] ContinuePendingUnwind resume:@2 4: [ 0] SetVariable 0 (e) [ 10] EnterScope [ 20] LoadImmediate 2 [ 38] LeaveUnwindContext [ 3c] Jump @3 String Table: 0: e 1: x
2021-06-10 15:04:38 +02:00
private:
Label m_entry_point;
LibJS: Implement bytecode generation for try..catch..finally EnterUnwindContext pushes an unwind context (exception handler and/or finalizer) onto a stack. LeaveUnwindContext pops the unwind context from that stack. Upon return to the interpreter loop we check whether the VM has an exception pending. If no unwind context is available we return from the loop. If an exception handler is available we clear the VM's exception, put the exception value into the accumulator register, clear the unwind context's handler and jump to the handler. If no handler is available but a finalizer is available we save the exception value + metadata (for later use by ContinuePendingUnwind), clear the VM's exception, pop the unwind context and jump to the finalizer. ContinuePendingUnwind checks whether a saved exception is available. If no saved exception is available it jumps to the resume label. Otherwise it stores the exception into the VM. The Jump after LeaveUnwindContext could be integrated into the LeaveUnwindContext instruction. I've kept them separate for now to make the bytecode more readable. > try { 1; throw "x" } catch (e) { 2 } finally { 3 }; 4 1: [ 0] EnterScope [ 10] EnterUnwindContext handler:@4 finalizer:@3 [ 38] EnterScope [ 48] LoadImmediate 1 [ 60] NewString 1 ("x") [ 70] Throw <for non-terminated blocks: insert LeaveUnwindContext + Jump @3 here> 2: [ 0] LoadImmediate 4 3: [ 0] EnterScope [ 10] LoadImmediate 3 [ 28] ContinuePendingUnwind resume:@2 4: [ 0] SetVariable 0 (e) [ 10] EnterScope [ 20] LoadImmediate 2 [ 38] LeaveUnwindContext [ 3c] Jump @3 String Table: 0: e 1: x
2021-06-10 15:04:38 +02:00
Optional<Label> m_handler_target;
Optional<Label> m_finalizer_target;
};
class LeaveUnwindContext final : public Instruction {
public:
LeaveUnwindContext()
: Instruction(Type::LeaveUnwindContext)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
LibJS: Implement bytecode generation for try..catch..finally EnterUnwindContext pushes an unwind context (exception handler and/or finalizer) onto a stack. LeaveUnwindContext pops the unwind context from that stack. Upon return to the interpreter loop we check whether the VM has an exception pending. If no unwind context is available we return from the loop. If an exception handler is available we clear the VM's exception, put the exception value into the accumulator register, clear the unwind context's handler and jump to the handler. If no handler is available but a finalizer is available we save the exception value + metadata (for later use by ContinuePendingUnwind), clear the VM's exception, pop the unwind context and jump to the finalizer. ContinuePendingUnwind checks whether a saved exception is available. If no saved exception is available it jumps to the resume label. Otherwise it stores the exception into the VM. The Jump after LeaveUnwindContext could be integrated into the LeaveUnwindContext instruction. I've kept them separate for now to make the bytecode more readable. > try { 1; throw "x" } catch (e) { 2 } finally { 3 }; 4 1: [ 0] EnterScope [ 10] EnterUnwindContext handler:@4 finalizer:@3 [ 38] EnterScope [ 48] LoadImmediate 1 [ 60] NewString 1 ("x") [ 70] Throw <for non-terminated blocks: insert LeaveUnwindContext + Jump @3 here> 2: [ 0] LoadImmediate 4 3: [ 0] EnterScope [ 10] LoadImmediate 3 [ 28] ContinuePendingUnwind resume:@2 4: [ 0] SetVariable 0 (e) [ 10] EnterScope [ 20] LoadImmediate 2 [ 38] LeaveUnwindContext [ 3c] Jump @3 String Table: 0: e 1: x
2021-06-10 15:04:38 +02:00
};
class ContinuePendingUnwind final : public Instruction {
public:
constexpr static bool IsTerminator = true;
explicit ContinuePendingUnwind(Label resume_target)
LibJS: Implement bytecode generation for try..catch..finally EnterUnwindContext pushes an unwind context (exception handler and/or finalizer) onto a stack. LeaveUnwindContext pops the unwind context from that stack. Upon return to the interpreter loop we check whether the VM has an exception pending. If no unwind context is available we return from the loop. If an exception handler is available we clear the VM's exception, put the exception value into the accumulator register, clear the unwind context's handler and jump to the handler. If no handler is available but a finalizer is available we save the exception value + metadata (for later use by ContinuePendingUnwind), clear the VM's exception, pop the unwind context and jump to the finalizer. ContinuePendingUnwind checks whether a saved exception is available. If no saved exception is available it jumps to the resume label. Otherwise it stores the exception into the VM. The Jump after LeaveUnwindContext could be integrated into the LeaveUnwindContext instruction. I've kept them separate for now to make the bytecode more readable. > try { 1; throw "x" } catch (e) { 2 } finally { 3 }; 4 1: [ 0] EnterScope [ 10] EnterUnwindContext handler:@4 finalizer:@3 [ 38] EnterScope [ 48] LoadImmediate 1 [ 60] NewString 1 ("x") [ 70] Throw <for non-terminated blocks: insert LeaveUnwindContext + Jump @3 here> 2: [ 0] LoadImmediate 4 3: [ 0] EnterScope [ 10] LoadImmediate 3 [ 28] ContinuePendingUnwind resume:@2 4: [ 0] SetVariable 0 (e) [ 10] EnterScope [ 20] LoadImmediate 2 [ 38] LeaveUnwindContext [ 3c] Jump @3 String Table: 0: e 1: x
2021-06-10 15:04:38 +02:00
: Instruction(Type::ContinuePendingUnwind)
, m_resume_target(resume_target)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
LibJS: Implement bytecode generation for try..catch..finally EnterUnwindContext pushes an unwind context (exception handler and/or finalizer) onto a stack. LeaveUnwindContext pops the unwind context from that stack. Upon return to the interpreter loop we check whether the VM has an exception pending. If no unwind context is available we return from the loop. If an exception handler is available we clear the VM's exception, put the exception value into the accumulator register, clear the unwind context's handler and jump to the handler. If no handler is available but a finalizer is available we save the exception value + metadata (for later use by ContinuePendingUnwind), clear the VM's exception, pop the unwind context and jump to the finalizer. ContinuePendingUnwind checks whether a saved exception is available. If no saved exception is available it jumps to the resume label. Otherwise it stores the exception into the VM. The Jump after LeaveUnwindContext could be integrated into the LeaveUnwindContext instruction. I've kept them separate for now to make the bytecode more readable. > try { 1; throw "x" } catch (e) { 2 } finally { 3 }; 4 1: [ 0] EnterScope [ 10] EnterUnwindContext handler:@4 finalizer:@3 [ 38] EnterScope [ 48] LoadImmediate 1 [ 60] NewString 1 ("x") [ 70] Throw <for non-terminated blocks: insert LeaveUnwindContext + Jump @3 here> 2: [ 0] LoadImmediate 4 3: [ 0] EnterScope [ 10] LoadImmediate 3 [ 28] ContinuePendingUnwind resume:@2 4: [ 0] SetVariable 0 (e) [ 10] EnterScope [ 20] LoadImmediate 2 [ 38] LeaveUnwindContext [ 3c] Jump @3 String Table: 0: e 1: x
2021-06-10 15:04:38 +02:00
private:
Label m_resume_target;
};
class Yield final : public Instruction {
public:
constexpr static bool IsTerminator = true;
explicit Yield(Label continuation_label)
: Instruction(Type::Yield)
, m_continuation_label(continuation_label)
{
}
explicit Yield(std::nullptr_t)
: Instruction(Type::Yield)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
Optional<Label> m_continuation_label;
};
class PushLexicalEnvironment final : public Instruction {
public:
explicit PushLexicalEnvironment(HashMap<u32, Variable> variables)
: Instruction(Type::PushLexicalEnvironment)
, m_variables(move(variables))
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
HashMap<u32, Variable> m_variables;
};
class LoadArgument final : public Instruction {
public:
explicit LoadArgument(size_t index)
: Instruction(Type::LoadArgument)
, m_index(index)
{
}
void execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
private:
size_t m_index { 0 };
};
}
namespace JS::Bytecode {
ALWAYS_INLINE void Instruction::execute(Bytecode::Interpreter& interpreter) const
{
#define __BYTECODE_OP(op) \
case Instruction::Type::op: \
return static_cast<Bytecode::Op::op const&>(*this).execute_impl(interpreter);
switch (type()) {
ENUMERATE_BYTECODE_OPS(__BYTECODE_OP)
default:
VERIFY_NOT_REACHED();
}
#undef __BYTECODE_OP
}
ALWAYS_INLINE size_t Instruction::length() const
{
if (type() == Type::Call)
return static_cast<Op::Call const&>(*this).length_impl();
else if (type() == Type::NewArray)
return static_cast<Op::NewArray const&>(*this).length_impl();
#define __BYTECODE_OP(op) \
case Type::op: \
return sizeof(Op::op);
switch (type()) {
ENUMERATE_BYTECODE_OPS(__BYTECODE_OP)
default:
VERIFY_NOT_REACHED();
}
#undef __BYTECODE_OP
}
}