LibJS: Make Reference aware of DeclarativeEnvironment indices

VM::resolve_binding() can now return a Reference that knows the exact
binding index if it's pointing into a DeclarativeEnvironment.

Reading/writing through the Reference will now use direct environment
access when possible.
This commit is contained in:
Andreas Kling 2021-10-07 00:16:37 +02:00
parent 540ce075b6
commit 4444bcabde
Notes: sideshowbarker 2024-07-18 02:59:19 +09:00
3 changed files with 14 additions and 4 deletions

View file

@ -5,6 +5,7 @@
*/ */
#include <LibJS/AST.h> #include <LibJS/AST.h>
#include <LibJS/Runtime/DeclarativeEnvironment.h>
#include <LibJS/Runtime/Error.h> #include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/GlobalObject.h> #include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/Reference.h> #include <LibJS/Runtime/Reference.h>
@ -48,7 +49,10 @@ void Reference::put_value(GlobalObject& global_object, Value value)
VERIFY(m_base_type == BaseType::Environment); VERIFY(m_base_type == BaseType::Environment);
VERIFY(m_base_environment); VERIFY(m_base_environment);
m_base_environment->set_mutable_binding(global_object, m_name.as_string(), value, m_strict); if (m_index_in_declarative_environment.has_value())
static_cast<DeclarativeEnvironment*>(m_base_environment)->set_mutable_binding_direct(global_object, m_index_in_declarative_environment.value(), value, m_strict);
else
m_base_environment->set_mutable_binding(global_object, m_name.as_string(), value, m_strict);
} }
void Reference::throw_reference_error(GlobalObject& global_object) const void Reference::throw_reference_error(GlobalObject& global_object) const
@ -77,6 +81,8 @@ Value Reference::get_value(GlobalObject& global_object) const
VERIFY(m_base_type == BaseType::Environment); VERIFY(m_base_type == BaseType::Environment);
VERIFY(m_base_environment); VERIFY(m_base_environment);
if (m_index_in_declarative_environment.has_value())
return static_cast<DeclarativeEnvironment*>(m_base_environment)->get_binding_value_direct(global_object, m_index_in_declarative_environment.value(), m_strict);
return m_base_environment->get_binding_value(global_object, m_name.as_string(), m_strict); return m_base_environment->get_binding_value(global_object, m_name.as_string(), m_strict);
} }

View file

@ -44,11 +44,12 @@ public:
} }
} }
Reference(Environment& base, FlyString referenced_name, bool strict = false) Reference(Environment& base, FlyString referenced_name, bool strict = false, Optional<size_t> index_in_declarative_environment = {})
: m_base_type(BaseType::Environment) : m_base_type(BaseType::Environment)
, m_base_environment(&base) , m_base_environment(&base)
, m_name(move(referenced_name)) , m_name(move(referenced_name))
, m_strict(strict) , m_strict(strict)
, m_index_in_declarative_environment(move(index_in_declarative_environment))
{ {
} }
@ -129,6 +130,7 @@ private:
PropertyName m_name; PropertyName m_name;
Value m_this_value; Value m_this_value;
bool m_strict { false }; bool m_strict { false };
Optional<size_t> m_index_in_declarative_environment;
}; };
} }

View file

@ -442,12 +442,14 @@ Reference VM::get_identifier_reference(Environment* environment, FlyString name,
// a. Return the Reference Record { [[Base]]: unresolvable, [[ReferencedName]]: name, [[Strict]]: strict, [[ThisValue]]: empty }. // a. Return the Reference Record { [[Base]]: unresolvable, [[ReferencedName]]: name, [[Strict]]: strict, [[ThisValue]]: empty }.
return Reference { Reference::BaseType::Unresolvable, move(name), strict }; return Reference { Reference::BaseType::Unresolvable, move(name), strict };
} }
auto exists = environment->has_binding(name);
Optional<size_t> index;
auto exists = environment->has_binding(name, &index);
if (exception()) if (exception())
return {}; return {};
if (exists) if (exists)
return Reference { *environment, move(name), strict }; return Reference { *environment, move(name), strict, index };
else else
return get_identifier_reference(environment->outer_environment(), move(name), strict); return get_identifier_reference(environment->outer_environment(), move(name), strict);
} }