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use crate::{
bytecompiler::{Access, BindingAccessOpcode, ByteCompiler, Label, Register, ToJsString},
vm::opcode::BindingOpcode,
};
use boa_ast::{
Expression,
expression::{
access::{PropertyAccess, PropertyAccessField},
operator::{Assign, assign::AssignOp},
},
scope::BindingLocatorError,
};
impl ByteCompiler<'_> {
pub(crate) fn compile_assign(&mut self, assign: &Assign, dst: &Register) {
let mut compiler = self.position_guard(assign);
if assign.op() == AssignOp::Assign {
match Access::from_assign_target(assign.lhs()) {
Ok(access) => {
compiler.access_set(access, |compiler| {
compiler.compile_expr(assign.rhs(), dst);
dst
});
}
Err(pattern) => {
compiler.compile_expr(assign.rhs(), dst);
compiler.compile_declaration_pattern(pattern, BindingOpcode::SetName, dst);
}
}
} else {
let access = Access::from_assign_target(assign.lhs())
.expect("patterns should throw early errors on complex assignment operators");
let short_circuit = matches!(
assign.op(),
AssignOp::BoolAnd | AssignOp::BoolOr | AssignOp::Coalesce
);
let emit = |compiler: &mut Self,
dst: &Register,
expr: &Expression,
op: AssignOp|
-> Option<Label> {
if short_circuit {
let next = compiler.next_opcode_location();
match op {
AssignOp::BoolAnd => compiler
.bytecode
.emit_logical_and(Self::DUMMY_ADDRESS, dst.variable()),
AssignOp::BoolOr => compiler
.bytecode
.emit_logical_or(Self::DUMMY_ADDRESS, dst.variable()),
AssignOp::Coalesce => compiler
.bytecode
.emit_coalesce(Self::DUMMY_ADDRESS, dst.variable()),
_ => unreachable!(),
}
compiler.compile_expr(expr, dst);
Some(Label { index: next })
} else {
let rhs = compiler.register_allocator.alloc();
compiler.compile_expr(expr, &rhs);
match op {
AssignOp::Add => compiler.bytecode.emit_add(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Sub => compiler.bytecode.emit_sub(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Mul => compiler.bytecode.emit_mul(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Div => compiler.bytecode.emit_div(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Mod => compiler.bytecode.emit_mod(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Exp => compiler.bytecode.emit_pow(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::And => compiler.bytecode.emit_bit_and(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Or => compiler.bytecode.emit_bit_or(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Xor => compiler.bytecode.emit_bit_xor(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Shl => compiler.bytecode.emit_shift_left(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Shr => compiler.bytecode.emit_shift_right(
dst.variable(),
dst.variable(),
rhs.variable(),
),
AssignOp::Ushr => compiler.bytecode.emit_unsigned_shift_right(
dst.variable(),
dst.variable(),
rhs.variable(),
),
_ => unreachable!(),
}
compiler.register_allocator.dealloc(rhs);
None
}
};
let early_exit;
match access {
Access::Variable { name } => {
let name = name.to_js_string(compiler.interner());
let binding = compiler
.lexical_scope
.get_identifier_reference(name.clone());
let is_lexical = binding.is_lexical();
let index = compiler.get_binding(&binding);
if is_lexical {
compiler.emit_binding_access(BindingAccessOpcode::GetName, &index, dst);
} else {
compiler.emit_binding_access(
BindingAccessOpcode::GetNameAndLocator,
&index,
dst,
);
}
early_exit = emit(&mut compiler, dst, assign.rhs(), assign.op());
if is_lexical {
match compiler.lexical_scope.set_mutable_binding(name.clone()) {
Ok(binding) => {
let index = compiler.insert_binding(binding);
compiler.emit_binding_access(
BindingAccessOpcode::SetName,
&index,
dst,
);
}
Err(BindingLocatorError::MutateImmutable) => {
let index = compiler.get_or_insert_string(name);
compiler.bytecode.emit_throw_mutate_immutable(index.into());
}
Err(BindingLocatorError::Silent) => {}
}
} else {
compiler.emit_binding_access(
BindingAccessOpcode::SetNameByLocator,
&index,
dst,
);
}
}
Access::Property { access } => match access {
PropertyAccess::Simple(access) => match access.field() {
PropertyAccessField::Const(name) => {
let object = compiler.register_allocator.alloc();
compiler.compile_expr(access.target(), &object);
compiler.emit_get_property_by_name(dst, &object, &object, name.sym());
early_exit = emit(&mut compiler, dst, assign.rhs(), assign.op());
compiler.emit_set_property_by_name(dst, &object, &object, name.sym());
compiler.register_allocator.dealloc(object);
}
PropertyAccessField::Expr(expr) => {
let object = compiler.register_allocator.alloc();
compiler.compile_expr(access.target(), &object);
let key = compiler.register_allocator.alloc();
compiler.compile_expr(expr, &key);
compiler.bytecode.emit_get_property_by_value_push(
dst.variable(),
key.variable(),
object.variable(),
object.variable(),
);
early_exit = emit(&mut compiler, dst, assign.rhs(), assign.op());
compiler.bytecode.emit_set_property_by_value(
dst.variable(),
key.variable(),
object.variable(),
object.variable(),
);
compiler.register_allocator.dealloc(key);
compiler.register_allocator.dealloc(object);
}
},
PropertyAccess::Private(access) => {
let index = compiler.get_or_insert_private_name(access.field());
let object = compiler.register_allocator.alloc();
compiler.compile_expr(access.target(), &object);
compiler.bytecode.emit_get_private_field(
dst.variable(),
object.variable(),
index.into(),
);
early_exit = emit(&mut compiler, dst, assign.rhs(), assign.op());
compiler.bytecode.emit_set_private_field(
dst.variable(),
object.variable(),
index.into(),
);
compiler.register_allocator.dealloc(object);
}
PropertyAccess::Super(access) => match access.field() {
PropertyAccessField::Const(name) => {
let object = compiler.register_allocator.alloc();
let receiver = compiler.register_allocator.alloc();
compiler.bytecode.emit_super(object.variable());
compiler.bytecode.emit_this(receiver.variable());
compiler.emit_get_property_by_name(dst, &receiver, &object, name.sym());
early_exit = emit(&mut compiler, dst, assign.rhs(), assign.op());
compiler.emit_set_property_by_name(dst, &receiver, &object, name.sym());
compiler.register_allocator.dealloc(receiver);
compiler.register_allocator.dealloc(object);
}
PropertyAccessField::Expr(expr) => {
let object = compiler.register_allocator.alloc();
let receiver = compiler.register_allocator.alloc();
compiler.bytecode.emit_super(object.variable());
compiler.bytecode.emit_this(receiver.variable());
let key = compiler.register_allocator.alloc();
compiler.compile_expr(expr, &key);
compiler.bytecode.emit_get_property_by_value_push(
dst.variable(),
key.variable(),
receiver.variable(),
object.variable(),
);
early_exit = emit(&mut compiler, dst, assign.rhs(), assign.op());
compiler.bytecode.emit_set_property_by_value(
dst.variable(),
key.variable(),
receiver.variable(),
object.variable(),
);
compiler.register_allocator.dealloc(key);
compiler.register_allocator.dealloc(receiver);
compiler.register_allocator.dealloc(object);
}
},
},
Access::This => unreachable!(),
}
if let Some(early_exit) = early_exit {
let skip = compiler.jump();
compiler.patch_jump(early_exit);
compiler.patch_jump(skip);
}
}
}
}