RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 15:57:34 +00:00
Code Issues Activity Actions

LibJS: More properly implement scoping rules in bytecode codegen

Browse source 
Now we emit CreateVariable and SetVariable with the appropriate
initialization/environment modes, much closer to the spec.
This makes a whole lot of things like let/const variables, function
and variable hoisting and some other things work :^)
This commit is contained in:
Ali Mohammad Pur 2022-02-12 19:48:45 +03:30 • committed by Linus Groh
parent c7e6b65fd2
commit 1bbfaf8627
12 changed files with 503 additions and 38 deletions
Download patch file Download diff file Expand all files Collapse all files

72
Userland/Libraries/LibJS/Bytecode/Op.h
View file

@ -282,11 +282,34 @@ private:
Register m_lhs;
};
class SetVariable final : public Instruction {
enum class EnvironmentMode {
Lexical,
Var,
};
class CreateEnvironment final : public Instruction {
public:
explicit SetVariable(IdentifierTableIndex identifier)
: Instruction(Type::SetVariable)
explicit CreateEnvironment(EnvironmentMode mode)
: Instruction(Type::CreateEnvironment)
, m_mode(mode)
{
}
ThrowCompletionOr<void> execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
void replace_references_impl(BasicBlock const&, BasicBlock const&) { }
private:
EnvironmentMode m_mode { EnvironmentMode::Lexical };
};
class CreateVariable final : public Instruction {
public:
explicit CreateVariable(IdentifierTableIndex identifier, EnvironmentMode mode, bool is_immutable)
: Instruction(Type::CreateVariable)
, m_identifier(identifier)
, m_mode(mode)
, m_is_immutable(is_immutable)
{
}
@ -296,6 +319,33 @@ public:
private:
IdentifierTableIndex m_identifier;
EnvironmentMode m_mode;
bool m_is_immutable { false };
};
class SetVariable final : public Instruction {
public:
enum class InitializationMode {
Initialize,
Set,
InitializeOrSet,
};
explicit SetVariable(IdentifierTableIndex identifier, InitializationMode initialization_mode = InitializationMode::Set, EnvironmentMode mode = EnvironmentMode::Lexical)
: Instruction(Type::SetVariable)
, m_identifier(identifier)
, m_mode(mode)
, m_initialization_mode(initialization_mode)
{
}
ThrowCompletionOr<void> execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
void replace_references_impl(BasicBlock const&, BasicBlock const&) { }
private:
IdentifierTableIndex m_identifier;
EnvironmentMode m_mode;
InitializationMode m_initialization_mode { InitializationMode::Set };
};
class GetVariable final : public Instruction {
@ -599,6 +649,22 @@ private:
Optional<Label> m_finalizer_target;
};
class LeaveEnvironment final : public Instruction {
public:
LeaveEnvironment(EnvironmentMode mode)
: Instruction(Type::LeaveEnvironment)
, m_mode(mode)
{
}
ThrowCompletionOr<void> execute_impl(Bytecode::Interpreter&) const;
String to_string_impl(Bytecode::Executable const&) const;
void replace_references_impl(BasicBlock const&, BasicBlock const&) { }
private:
EnvironmentMode m_mode { EnvironmentMode::Lexical };
};
class LeaveUnwindContext final : public Instruction {
public:
LeaveUnwindContext()