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refactor(minifier): side effect detection needs symbols resolution (#8715)

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Boshen 2025-01-25 15:00:59 +00:00
parent 4a2f2a9cd9
commit 0af0267077
14 changed files with 156 additions and 409 deletions
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31
crates/oxc_ecmascript/src/constant_evaluation/mod.rs
View file

@ -14,11 +14,7 @@ pub use is_literal_value::IsLiteralValue;
pub use value::ConstantValue; pub use value::ConstantValue;
pub use value_type::ValueType; pub use value_type::ValueType;
pub trait ConstantEvaluation<'a> { pub trait ConstantEvaluation<'a>: MayHaveSideEffects<'a> {
fn is_global_reference(&self, ident: &IdentifierReference<'a>) -> bool {
matches!(ident.name.as_str(), "undefined" | "NaN" | "Infinity")
}
fn resolve_binding(&self, ident: &IdentifierReference<'a>) -> Option<ConstantValue<'a>> { fn resolve_binding(&self, ident: &IdentifierReference<'a>) -> Option<ConstantValue<'a>> {
match ident.name.as_str() { match ident.name.as_str() {
"undefined" if self.is_global_reference(ident) => Some(ConstantValue::Undefined), "undefined" if self.is_global_reference(ident) => Some(ConstantValue::Undefined),
@ -36,7 +32,7 @@ pub trait ConstantEvaluation<'a> {
// and there are only a very few cases where we can compute a number value, but there could // and there are only a very few cases where we can compute a number value, but there could
// also be side effects. e.g. `void doSomething()` has value NaN, regardless of the behavior // also be side effects. e.g. `void doSomething()` has value NaN, regardless of the behavior
// of `doSomething()` // of `doSomething()`
if value.is_some() && expr.may_have_side_effects() { if value.is_some() && self.expression_may_have_side_efffects(expr) {
None None
} else { } else {
value value
@ -45,7 +41,7 @@ pub trait ConstantEvaluation<'a> {
fn get_side_free_string_value(&self, expr: &Expression<'a>) -> Option<Cow<'a, str>> { fn get_side_free_string_value(&self, expr: &Expression<'a>) -> Option<Cow<'a, str>> {
let value = expr.to_js_string(); let value = expr.to_js_string();
if value.is_some() && !expr.may_have_side_effects() { if value.is_some() && !self.expression_may_have_side_efffects(expr) {
return value; return value;
} }
None None
@ -53,7 +49,7 @@ pub trait ConstantEvaluation<'a> {
fn get_side_free_boolean_value(&self, expr: &Expression<'a>) -> Option<bool> { fn get_side_free_boolean_value(&self, expr: &Expression<'a>) -> Option<bool> {
let value = self.get_boolean_value(expr); let value = self.get_boolean_value(expr);
if value.is_some() && !expr.may_have_side_effects() { if value.is_some() && !self.expression_may_have_side_efffects(expr) {
return value; return value;
} }
None None
@ -61,7 +57,7 @@ pub trait ConstantEvaluation<'a> {
fn get_side_free_bigint_value(&self, expr: &Expression<'a>) -> Option<BigInt> { fn get_side_free_bigint_value(&self, expr: &Expression<'a>) -> Option<BigInt> {
let value = expr.to_big_int(); let value = expr.to_big_int();
if value.is_some() && expr.may_have_side_effects() { if value.is_some() && self.expression_may_have_side_efffects(expr) {
None None
} else { } else {
value value
@ -205,7 +201,9 @@ pub trait ConstantEvaluation<'a> {
) -> Option<ConstantValue<'a>> { ) -> Option<ConstantValue<'a>> {
match operator { match operator {
BinaryOperator::Addition => { BinaryOperator::Addition => {
if left.may_have_side_effects() || right.may_have_side_effects() { if self.expression_may_have_side_efffects(left)
|| self.expression_may_have_side_efffects(right)
{
return None; return None;
} }
let left_type = ValueType::from(left); let left_type = ValueType::from(left);
@ -321,7 +319,7 @@ pub trait ConstantEvaluation<'a> {
None None
} }
BinaryOperator::Instanceof => { BinaryOperator::Instanceof => {
if left.may_have_side_effects() { if self.expression_may_have_side_efffects(left) {
return None; return None;
} }
if let Expression::Identifier(right_ident) = right { if let Expression::Identifier(right_ident) = right {
@ -380,8 +378,9 @@ pub trait ConstantEvaluation<'a> {
}; };
Some(ConstantValue::String(Cow::Borrowed(s))) Some(ConstantValue::String(Cow::Borrowed(s)))
} }
UnaryOperator::Void => (expr.argument.is_literal() || !expr.may_have_side_effects()) UnaryOperator::Void => (expr.argument.is_literal()
.then_some(ConstantValue::Undefined), || !self.expression_may_have_side_efffects(&expr.argument))
.then_some(ConstantValue::Undefined),
UnaryOperator::LogicalNot => self UnaryOperator::LogicalNot => self
.get_side_free_boolean_value(&expr.argument) .get_side_free_boolean_value(&expr.argument)
.map(|b| !b) .map(|b| !b)
@ -424,10 +423,9 @@ pub trait ConstantEvaluation<'a> {
if let Some(ConstantValue::String(s)) = self.eval_expression(&expr.object) { if let Some(ConstantValue::String(s)) = self.eval_expression(&expr.object) {
Some(ConstantValue::Number(s.encode_utf16().count().to_f64().unwrap())) Some(ConstantValue::Number(s.encode_utf16().count().to_f64().unwrap()))
} else { } else {
if expr.object.may_have_side_effects() { if self.expression_may_have_side_efffects(&expr.object) {
return None; return None;
} }
if let Expression::ArrayExpression(arr) = &expr.object { if let Expression::ArrayExpression(arr) = &expr.object {
Some(ConstantValue::Number(arr.elements.len().to_f64().unwrap())) Some(ConstantValue::Number(arr.elements.len().to_f64().unwrap()))
} else { } else {
@ -448,10 +446,9 @@ pub trait ConstantEvaluation<'a> {
if let Some(ConstantValue::String(s)) = self.eval_expression(&expr.object) { if let Some(ConstantValue::String(s)) = self.eval_expression(&expr.object) {
Some(ConstantValue::Number(s.encode_utf16().count().to_f64().unwrap())) Some(ConstantValue::Number(s.encode_utf16().count().to_f64().unwrap()))
} else { } else {
if expr.object.may_have_side_effects() { if self.expression_may_have_side_efffects(&expr.object) {
return None; return None;
} }
if let Expression::ArrayExpression(arr) = &expr.object { if let Expression::ArrayExpression(arr) = &expr.object {
Some(ConstantValue::Number(arr.elements.len().to_f64().unwrap())) Some(ConstantValue::Number(arr.elements.len().to_f64().unwrap()))
} else { } else {

348
crates/oxc_ecmascript/src/side_effects/check_for_state_change.rs
View file

@ -1,348 +0,0 @@
use oxc_ast::ast::*;
use oxc_syntax::operator::{BinaryOperator, UnaryOperator};
/// A "simple" operator is one whose children are expressions, has no direct side-effects.
fn is_simple_unary_operator(operator: UnaryOperator) -> bool {
operator != UnaryOperator::Delete
}
/// Returns true if some node in n's subtree changes application state. If
/// `check_for_new_objects` is true, we assume that newly created mutable objects (like object
/// literals) change state. Otherwise, we assume that they have no side effects.
///
/// Ported from [closure-compiler](https://github.com/google/closure-compiler/blob/f3ce5ed8b630428e311fe9aa2e20d36560d975e2/src/com/google/javascript/jscomp/AstAnalyzer.java#L241)
pub trait CheckForStateChange<'a, 'b> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool;
}
impl<'a> CheckForStateChange<'a, '_> for Expression<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match self {
Self::NumericLiteral(_)
| Self::BooleanLiteral(_)
| Self::StringLiteral(_)
| Self::BigIntLiteral(_)
| Self::NullLiteral(_)
| Self::RegExpLiteral(_)
| Self::MetaProperty(_)
| Self::ThisExpression(_)
| Self::ArrowFunctionExpression(_)
| Self::FunctionExpression(_) => false,
Self::ClassExpression(class_expr) => class_expr
.body
.body
.iter()
.any(|method| method.check_for_state_change(check_for_new_objects)),
Self::TemplateLiteral(template) => template
.expressions
.iter()
.any(|expr| expr.check_for_state_change(check_for_new_objects)),
Self::Identifier(ident) => match ident.name.as_str() {
"undefined" | "NaN" | "Infinity" => false,
// Reference read can have a side effect.
_ => true,
},
Self::UnaryExpression(unary_expr) => {
unary_expr.check_for_state_change(check_for_new_objects)
}
Self::ParenthesizedExpression(p) => {
p.expression.check_for_state_change(check_for_new_objects)
}
Self::ConditionalExpression(p) => {
p.test.check_for_state_change(check_for_new_objects)
|| p.consequent.check_for_state_change(check_for_new_objects)
|| p.alternate.check_for_state_change(check_for_new_objects)
}
Self::SequenceExpression(s) => {
s.expressions.iter().any(|expr| expr.check_for_state_change(check_for_new_objects))
}
Self::BinaryExpression(binary_expr) => {
binary_expr.check_for_state_change(check_for_new_objects)
}
Self::ObjectExpression(object_expr) => {
if check_for_new_objects {
return true;
}
object_expr
.properties
.iter()
.any(|property| property.check_for_state_change(check_for_new_objects))
}
Self::ArrayExpression(array_expr) => {
if check_for_new_objects {
return true;
}
array_expr
.elements
.iter()
.any(|element| element.check_for_state_change(check_for_new_objects))
}
_ => true,
}
}
}
impl<'a> CheckForStateChange<'a, '_> for UnaryExpression<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
if is_simple_unary_operator(self.operator) {
return self.argument.check_for_state_change(check_for_new_objects);
}
true
}
}
impl<'a> CheckForStateChange<'a, '_> for BinaryExpression<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
// `instanceof` and `in` can throw `TypeError`
if matches!(self.operator, BinaryOperator::In | BinaryOperator::Instanceof) {
return true;
}
let left = self.left.check_for_state_change(check_for_new_objects);
if left {
return true;
}
self.right.check_for_state_change(check_for_new_objects)
}
}
impl<'a> CheckForStateChange<'a, '_> for ArrayExpressionElement<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match self {
Self::SpreadElement(element) => element.check_for_state_change(check_for_new_objects),
match_expression!(Self) => {
self.to_expression().check_for_state_change(check_for_new_objects)
}
Self::Elision(_) => false,
}
}
}
impl<'a> CheckForStateChange<'a, '_> for ObjectPropertyKind<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match self {
Self::ObjectProperty(method) => method.check_for_state_change(check_for_new_objects),
Self::SpreadProperty(spread_element) => {
spread_element.check_for_state_change(check_for_new_objects)
}
}
}
}
impl<'a> CheckForStateChange<'a, '_> for SpreadElement<'a> {
fn check_for_state_change(&self, _check_for_new_objects: bool) -> bool {
// Object-rest and object-spread may trigger a getter.
// TODO: Closure Compiler assumes that getters may side-free when set `assumeGettersArePure`.
// https://github.com/google/closure-compiler/blob/a4c880032fba961f7a6c06ef99daa3641810bfdd/src/com/google/javascript/jscomp/AstAnalyzer.java#L282
true
}
}
impl<'a> CheckForStateChange<'a, '_> for ObjectProperty<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
self.key.check_for_state_change(check_for_new_objects)
|| self.value.check_for_state_change(check_for_new_objects)
}
}
impl<'a> CheckForStateChange<'a, '_> for PropertyKey<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match self {
Self::StaticIdentifier(_) | Self::PrivateIdentifier(_) => false,
match_expression!(Self) => {
self.to_expression().check_for_state_change(check_for_new_objects)
}
}
}
}
impl<'a> CheckForStateChange<'a, '_> for ForStatementLeft<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match self {
match_assignment_target!(Self) => {
self.to_assignment_target().check_for_state_change(check_for_new_objects)
}
ForStatementLeft::VariableDeclaration(variable_declaration) => {
variable_declaration.check_for_state_change(check_for_new_objects)
}
}
}
}
impl<'a> CheckForStateChange<'a, '_> for VariableDeclaration<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
self.declarations.iter().any(|decl| decl.check_for_state_change(check_for_new_objects))
}
}
impl<'a> CheckForStateChange<'a, '_> for VariableDeclarator<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
self.id.check_for_state_change(check_for_new_objects)
|| self
.init
.as_ref()
.is_some_and(|init| init.check_for_state_change(check_for_new_objects))
}
}
impl CheckForStateChange<'_, '_> for BindingPattern<'_> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match &self.kind {
BindingPatternKind::BindingIdentifier(_) => false,
BindingPatternKind::ObjectPattern(object_pattern) => {
object_pattern
.properties
.iter()
.any(|element| element.check_for_state_change(check_for_new_objects))
|| object_pattern
.rest
.as_ref()
.is_some_and(|rest| rest.check_for_state_change(check_for_new_objects))
}
BindingPatternKind::ArrayPattern(array_pattern) => {
array_pattern.elements.iter().any(|element| {
element.as_ref().is_some_and(|element| {
element.check_for_state_change(check_for_new_objects)
})
}) || array_pattern
.rest
.as_ref()
.is_some_and(|rest| rest.check_for_state_change(check_for_new_objects))
}
BindingPatternKind::AssignmentPattern(assignment_pattern) => {
assignment_pattern.left.check_for_state_change(check_for_new_objects)
&& assignment_pattern.right.check_for_state_change(check_for_new_objects)
}
}
}
}
impl CheckForStateChange<'_, '_> for BindingRestElement<'_> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
self.argument.check_for_state_change(check_for_new_objects)
}
}
impl CheckForStateChange<'_, '_> for BindingProperty<'_> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
self.key.check_for_state_change(check_for_new_objects)
|| self.value.check_for_state_change(check_for_new_objects)
}
}
impl CheckForStateChange<'_, '_> for AssignmentTarget<'_> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match self {
AssignmentTarget::AssignmentTargetIdentifier(_) => false,
AssignmentTarget::TSAsExpression(ts_as_expression) => {
ts_as_expression.expression.check_for_state_change(check_for_new_objects)
}
AssignmentTarget::TSSatisfiesExpression(ts_satisfies_expression) => {
ts_satisfies_expression.expression.check_for_state_change(check_for_new_objects)
}
AssignmentTarget::TSNonNullExpression(ts_non_null_expression) => {
ts_non_null_expression.expression.check_for_state_change(check_for_new_objects)
}
AssignmentTarget::TSTypeAssertion(ts_type_assertion) => {
ts_type_assertion.expression.check_for_state_change(check_for_new_objects)
}
AssignmentTarget::TSInstantiationExpression(ts_instantiation_expression) => {
ts_instantiation_expression.expression.check_for_state_change(check_for_new_objects)
}
AssignmentTarget::ComputedMemberExpression(computed_member_expression) => {
computed_member_expression.object.check_for_state_change(check_for_new_objects)
|| computed_member_expression
.expression
.check_for_state_change(check_for_new_objects)
}
AssignmentTarget::StaticMemberExpression(static_member_expression) => {
static_member_expression.object.check_for_state_change(check_for_new_objects)
}
AssignmentTarget::PrivateFieldExpression(private_field_expression) => {
private_field_expression.object.check_for_state_change(check_for_new_objects)
}
AssignmentTarget::ArrayAssignmentTarget(array_assignment_target) => {
array_assignment_target.elements.iter().any(|element| {
element.as_ref().is_some_and(|element| {
element.check_for_state_change(check_for_new_objects)
})
}) || array_assignment_target
.rest
.as_ref()
.is_some_and(|rest| rest.check_for_state_change(check_for_new_objects))
}
AssignmentTarget::ObjectAssignmentTarget(object_assignment_target) => {
object_assignment_target
.properties
.iter()
.any(|property| property.check_for_state_change(check_for_new_objects))
|| object_assignment_target
.rest
.as_ref()
.is_some_and(|rest| rest.check_for_state_change(check_for_new_objects))
}
}
}
}
impl CheckForStateChange<'_, '_> for AssignmentTargetProperty<'_> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match self {
AssignmentTargetProperty::AssignmentTargetPropertyIdentifier(
assignment_target_property_identifier,
) => assignment_target_property_identifier
.init
.as_ref()
.is_some_and(|init| init.check_for_state_change(check_for_new_objects)),
AssignmentTargetProperty::AssignmentTargetPropertyProperty(
assignment_target_property_property,
) => {
assignment_target_property_property
.name
.check_for_state_change(check_for_new_objects)
|| assignment_target_property_property
.binding
.check_for_state_change(check_for_new_objects)
}
}
}
}
impl CheckForStateChange<'_, '_> for AssignmentTargetRest<'_> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
self.target.check_for_state_change(check_for_new_objects)
}
}
impl CheckForStateChange<'_, '_> for AssignmentTargetMaybeDefault<'_> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match self {
match_assignment_target!(Self) => {
self.to_assignment_target().check_for_state_change(check_for_new_objects)
}
Self::AssignmentTargetWithDefault(assignment_target_with_default) => {
assignment_target_with_default.binding.check_for_state_change(check_for_new_objects)
&& assignment_target_with_default
.init
.check_for_state_change(check_for_new_objects)
}
}
}
}
impl<'a> CheckForStateChange<'a, '_> for ClassElement<'a> {
fn check_for_state_change(&self, check_for_new_objects: bool) -> bool {
match self {
ClassElement::TSIndexSignature(_) | ClassElement::StaticBlock(_) => false,
ClassElement::MethodDefinition(method_definition) => {
method_definition.key.check_for_state_change(check_for_new_objects)
}
ClassElement::PropertyDefinition(property_definition) => {
property_definition.key.check_for_state_change(check_for_new_objects)
}
ClassElement::AccessorProperty(accessor_property) => {
accessor_property.key.check_for_state_change(check_for_new_objects)
}
}
}
}

122
crates/oxc_ecmascript/src/side_effects/may_have_side_effects.rs
View file

@ -1,22 +1,110 @@
use oxc_ast::ast::{Expression, ForStatementLeft, PropertyKey, UnaryExpression}; use oxc_ast::ast::*;
use super::check_for_state_change::CheckForStateChange; /// Returns true if subtree changes application state.
/// Returns true if the node which may have side effects when executed.
/// This version default to the "safe" assumptions when the compiler object
/// is not provided (RegExp have side-effects, etc).
/// ///
/// Ported from [closure-compiler](https://github.com/google/closure-compiler/blob/f3ce5ed8b630428e311fe9aa2e20d36560d975e2/src/com/google/javascript/jscomp/AstAnalyzer.java#L94) /// Ported from [closure-compiler](https://github.com/google/closure-compiler/blob/f3ce5ed8b630428e311fe9aa2e20d36560d975e2/src/com/google/javascript/jscomp/AstAnalyzer.java#L94)
pub trait MayHaveSideEffects<'a, 'b> pub trait MayHaveSideEffects<'a> {
where fn is_global_reference(&self, ident: &oxc_ast::ast::IdentifierReference<'a>) -> bool {
Self: CheckForStateChange<'a, 'b>, matches!(ident.name.as_str(), "undefined" | "NaN" | "Infinity")
{ }
fn may_have_side_effects(&self) -> bool {
self.check_for_state_change(/* check_for_new_objects */ false) fn expression_may_have_side_efffects(&self, e: &Expression<'a>) -> bool {
match e {
// Reference read can have a side effect.
Expression::Identifier(ident) => self.is_global_reference(ident),
Expression::NumericLiteral(_)
| Expression::BooleanLiteral(_)
| Expression::StringLiteral(_)
| Expression::BigIntLiteral(_)
| Expression::NullLiteral(_)
| Expression::RegExpLiteral(_)
| Expression::MetaProperty(_)
| Expression::ThisExpression(_)
| Expression::ArrowFunctionExpression(_)
| Expression::FunctionExpression(_) => false,
Expression::TemplateLiteral(template) => {
template.expressions.iter().any(|e| self.expression_may_have_side_efffects(e))
}
Expression::UnaryExpression(e) => self.unary_expression_may_have_side_effects(e),
Expression::ParenthesizedExpression(e) => {
self.expression_may_have_side_efffects(&e.expression)
}
Expression::ConditionalExpression(e) => {
self.expression_may_have_side_efffects(&e.test)
|| self.expression_may_have_side_efffects(&e.consequent)
|| self.expression_may_have_side_efffects(&e.alternate)
}
Expression::SequenceExpression(e) => {
e.expressions.iter().any(|e| self.expression_may_have_side_efffects(e))
}
Expression::BinaryExpression(e) => self.binary_expression_may_have_side_effects(e),
Expression::ObjectExpression(object_expr) => object_expr
.properties
.iter()
.any(|property| self.object_property_kind_may_have_side_effects(property)),
Expression::ArrayExpression(e) => e
.elements
.iter()
.any(|element| self.array_expression_element_may_have_side_effects(element)),
_ => true,
}
}
fn unary_expression_may_have_side_effects(&self, e: &UnaryExpression<'a>) -> bool {
/// A "simple" operator is one whose children are expressions, has no direct side-effects.
fn is_simple_unary_operator(operator: UnaryOperator) -> bool {
operator != UnaryOperator::Delete
}
if is_simple_unary_operator(e.operator) {
return self.expression_may_have_side_efffects(&e.argument);
}
true
}
fn binary_expression_may_have_side_effects(&self, e: &BinaryExpression<'a>) -> bool {
// `instanceof` and `in` can throw `TypeError`
if matches!(e.operator, BinaryOperator::In | BinaryOperator::Instanceof) {
return true;
}
self.expression_may_have_side_efffects(&e.left)
|| self.expression_may_have_side_efffects(&e.right)
}
fn array_expression_element_may_have_side_effects(
&self,
e: &ArrayExpressionElement<'a>,
) -> bool {
match e {
ArrayExpressionElement::SpreadElement(e) => {
self.expression_may_have_side_efffects(&e.argument)
}
match_expression!(ArrayExpressionElement) => {
self.expression_may_have_side_efffects(e.to_expression())
}
ArrayExpressionElement::Elision(_) => false,
}
}
fn object_property_kind_may_have_side_effects(&self, e: &ObjectPropertyKind<'a>) -> bool {
match e {
ObjectPropertyKind::ObjectProperty(o) => self.object_property_may_have_side_effects(o),
ObjectPropertyKind::SpreadProperty(e) => {
self.expression_may_have_side_efffects(&e.argument)
}
}
}
fn object_property_may_have_side_effects(&self, e: &ObjectProperty<'a>) -> bool {
self.property_key_may_have_side_effects(&e.key)
|| self.expression_may_have_side_efffects(&e.value)
}
fn property_key_may_have_side_effects(&self, key: &PropertyKey<'a>) -> bool {
match key {
PropertyKey::StaticIdentifier(_) | PropertyKey::PrivateIdentifier(_) => false,
match_expression!(PropertyKey) => {
self.expression_may_have_side_efffects(key.to_expression())
}
}
} }
} }
impl<'a> MayHaveSideEffects<'a, '_> for Expression<'a> {}
impl<'a> MayHaveSideEffects<'a, '_> for UnaryExpression<'a> {}
impl<'a> MayHaveSideEffects<'a, '_> for ForStatementLeft<'a> {}
impl<'a> MayHaveSideEffects<'a, '_> for PropertyKey<'a> {}

2
crates/oxc_ecmascript/src/side_effects/mod.rs
View file

@ -1,5 +1,3 @@
mod check_for_state_change;
mod may_have_side_effects; mod may_have_side_effects;
pub use check_for_state_change::CheckForStateChange;
pub use may_have_side_effects::MayHaveSideEffects; pub use may_have_side_effects::MayHaveSideEffects;

2
crates/oxc_minifier/examples/minifier.rs
View file

@ -27,7 +27,7 @@ fn main() -> std::io::Result<()> {
let mut allocator = Allocator::default(); let mut allocator = Allocator::default();
let printed = minify(&allocator, &source_text, source_type, mangle, nospace); let printed = minify(&allocator, &source_text, source_type, mangle, nospace);
// println!("{printed}"); println!("{printed}");
if twice { if twice {
allocator.reset(); allocator.reset();

11
crates/oxc_minifier/src/ctx.rs
View file

@ -1,7 +1,10 @@
use std::ops::Deref; use std::ops::Deref;
use oxc_ast::ast::*; use oxc_ast::ast::*;
use oxc_ecmascript::constant_evaluation::{ConstantEvaluation, ConstantValue}; use oxc_ecmascript::{
constant_evaluation::{ConstantEvaluation, ConstantValue},
side_effects::MayHaveSideEffects,
};
use oxc_semantic::{IsGlobalReference, SymbolTable}; use oxc_semantic::{IsGlobalReference, SymbolTable};
use oxc_traverse::TraverseCtx; use oxc_traverse::TraverseCtx;
@ -16,8 +19,10 @@ impl<'a, 'b> Deref for Ctx<'a, 'b> {
} }
} }
impl<'a> ConstantEvaluation<'a> for Ctx<'a, '_> { impl<'a> ConstantEvaluation<'a> for Ctx<'a, '_> {}
fn is_global_reference(&self, ident: &oxc_ast::ast::IdentifierReference<'a>) -> bool {
impl<'a> MayHaveSideEffects<'a> for Ctx<'a, '_> {
fn is_global_reference(&self, ident: &IdentifierReference<'a>) -> bool {
ident.is_global_reference(self.0.symbols()) ident.is_global_reference(self.0.symbols())
} }
} }

10
crates/oxc_minifier/src/peephole/fold_constants.rs
View file

@ -125,7 +125,7 @@ impl<'a, 'b> PeepholeOptimizations {
// (FALSE && x) => FALSE // (FALSE && x) => FALSE
if if lval { op == LogicalOperator::Or } else { op == LogicalOperator::And } { if if lval { op == LogicalOperator::Or } else { op == LogicalOperator::And } {
return Some(ctx.ast.move_expression(&mut logical_expr.left)); return Some(ctx.ast.move_expression(&mut logical_expr.left));
} else if !left.may_have_side_effects() { } else if !ctx.expression_may_have_side_efffects(left) {
let parent = ctx.ancestry.parent(); let parent = ctx.ancestry.parent();
// Bail `let o = { f() { assert.ok(this !== o); } }; (true && o.f)(); (true && o.f)``;` // Bail `let o = { f() { assert.ok(this !== o); } }; (true && o.f)(); (true && o.f)``;`
if parent.is_tagged_template_expression() if parent.is_tagged_template_expression()
@ -150,7 +150,7 @@ impl<'a, 'b> PeepholeOptimizations {
let left_child_right_boolean = ctx.get_boolean_value(&left_child.right); let left_child_right_boolean = ctx.get_boolean_value(&left_child.right);
let left_child_op = left_child.operator; let left_child_op = left_child.operator;
if let Some(right_boolean) = left_child_right_boolean { if let Some(right_boolean) = left_child_right_boolean {
if !left_child.right.may_have_side_effects() { if !ctx.expression_may_have_side_efffects(&left_child.right) {
// a || false || b => a || b // a || false || b => a || b
// a && true && b => a && b // a && true && b => a && b
if !right_boolean && left_child_op == LogicalOperator::Or if !right_boolean && left_child_op == LogicalOperator::Or
@ -183,7 +183,7 @@ impl<'a, 'b> PeepholeOptimizations {
let left_val = ValueType::from(left); let left_val = ValueType::from(left);
match left_val { match left_val {
ValueType::Null | ValueType::Undefined => { ValueType::Null | ValueType::Undefined => {
Some(if left.may_have_side_effects() { Some(if ctx.expression_may_have_side_efffects(left) {
// e.g. `(a(), null) ?? 1` => `(a(), null, 1)` // e.g. `(a(), null) ?? 1` => `(a(), null, 1)`
let expressions = ctx.ast.vec_from_array([ let expressions = ctx.ast.vec_from_array([
ctx.ast.move_expression(&mut logical_expr.left), ctx.ast.move_expression(&mut logical_expr.left),
@ -386,7 +386,9 @@ impl<'a, 'b> PeepholeOptimizations {
let left = &e.left; let left = &e.left;
let right = &e.right; let right = &e.right;
let op = e.operator; let op = e.operator;
if left.may_have_side_effects() || right.may_have_side_effects() { if ctx.expression_may_have_side_efffects(left)
|| ctx.expression_may_have_side_efffects(right)
{
return None; return None;
} }
let value = match op { let value = match op {

1
crates/oxc_minifier/src/peephole/minimize_conditions.rs
View file

@ -2,6 +2,7 @@ use oxc_allocator::Vec;
use oxc_ast::{ast::*, NONE}; use oxc_ast::{ast::*, NONE};
use oxc_ecmascript::{ use oxc_ecmascript::{
constant_evaluation::{ConstantEvaluation, ValueType}, constant_evaluation::{ConstantEvaluation, ValueType},
side_effects::MayHaveSideEffects,
ToInt32, ToInt32,
}; };
use oxc_span::{cmp::ContentEq, GetSpan}; use oxc_span::{cmp::ContentEq, GetSpan};

2
crates/oxc_minifier/src/peephole/normalize.rs
View file

@ -1,6 +1,6 @@
use oxc_allocator::Vec; use oxc_allocator::Vec;
use oxc_ast::ast::*; use oxc_ast::ast::*;
use oxc_ecmascript::constant_evaluation::ConstantEvaluation; use oxc_ecmascript::side_effects::MayHaveSideEffects;
use oxc_semantic::IsGlobalReference; use oxc_semantic::IsGlobalReference;
use oxc_span::GetSpan; use oxc_span::GetSpan;
use oxc_syntax::scope::ScopeFlags; use oxc_syntax::scope::ScopeFlags;

8
crates/oxc_minifier/src/peephole/remove_dead_code.rs
View file

@ -482,7 +482,7 @@ impl<'a, 'b> PeepholeOptimizations {
match ctx.get_boolean_value(&expr.test) { match ctx.get_boolean_value(&expr.test) {
Some(v) => { Some(v) => {
if expr.test.may_have_side_effects() { if ctx.expression_may_have_side_efffects(&expr.test) {
let mut exprs = ctx.ast.vec_with_capacity(2); let mut exprs = ctx.ast.vec_with_capacity(2);
exprs.push(ctx.ast.move_expression(&mut expr.test)); exprs.push(ctx.ast.move_expression(&mut expr.test));
exprs.push(ctx.ast.move_expression(if v { exprs.push(ctx.ast.move_expression(if v {
@ -519,7 +519,9 @@ impl<'a, 'b> PeepholeOptimizations {
let (should_fold, new_len) = sequence_expr.expressions.iter().enumerate().fold( let (should_fold, new_len) = sequence_expr.expressions.iter().enumerate().fold(
(false, 0), (false, 0),
|(mut should_fold, mut new_len), (i, expr)| { |(mut should_fold, mut new_len), (i, expr)| {
if i == sequence_expr.expressions.len() - 1 || expr.may_have_side_effects() { if i == sequence_expr.expressions.len() - 1
|| ctx.expression_may_have_side_efffects(expr)
{
new_len += 1; new_len += 1;
} else { } else {
should_fold = true; should_fold = true;
@ -536,7 +538,7 @@ impl<'a, 'b> PeepholeOptimizations {
let mut new_exprs = ctx.ast.vec_with_capacity(new_len); let mut new_exprs = ctx.ast.vec_with_capacity(new_len);
let len = sequence_expr.expressions.len(); let len = sequence_expr.expressions.len();
for (i, expr) in sequence_expr.expressions.iter_mut().enumerate() { for (i, expr) in sequence_expr.expressions.iter_mut().enumerate() {
if i == len - 1 || expr.may_have_side_effects() { if i == len - 1 || ctx.expression_may_have_side_efffects(expr) {
new_exprs.push(ctx.ast.move_expression(expr)); new_exprs.push(ctx.ast.move_expression(expr));
} }
} }

4
crates/oxc_minifier/src/peephole/replace_known_methods.rs
View file

@ -4,8 +4,8 @@ use cow_utils::CowUtils;
use oxc_ast::ast::*; use oxc_ast::ast::*;
use oxc_ecmascript::{ use oxc_ecmascript::{
constant_evaluation::ConstantEvaluation, StringCharAt, StringCharCodeAt, StringIndexOf, constant_evaluation::ConstantEvaluation, side_effects::MayHaveSideEffects, StringCharAt,
StringLastIndexOf, StringSubstring, ToInt32, StringCharCodeAt, StringIndexOf, StringLastIndexOf, StringSubstring, ToInt32,
}; };
use oxc_span::SPAN; use oxc_span::SPAN;
use oxc_syntax::es_target::ESTarget; use oxc_syntax::es_target::ESTarget;

8
crates/oxc_minifier/src/peephole/statement_fusion.rs
View file

@ -1,6 +1,5 @@
use oxc_allocator::Vec; use oxc_allocator::Vec;
use oxc_ast::ast::*; use oxc_ast::ast::*;
use oxc_ecmascript::side_effects::MayHaveSideEffects;
use oxc_span::GetSpan; use oxc_span::GetSpan;
use oxc_traverse::TraverseCtx; use oxc_traverse::TraverseCtx;
@ -67,7 +66,10 @@ impl<'a> PeepholeOptimizations {
for_stmt.init.is_none() for_stmt.init.is_none()
|| for_stmt.init.as_ref().is_some_and(ForStatementInit::is_expression) || for_stmt.init.as_ref().is_some_and(ForStatementInit::is_expression)
} }
Statement::ForInStatement(for_in_stmt) => !for_in_stmt.left.may_have_side_effects(), // Avoid cases where we have for(var x = foo() in a) { ....
Statement::ForInStatement(for_in_stmt) => {
!matches!(&for_in_stmt.left, ForStatementLeft::VariableDeclaration(_))
}
Statement::LabeledStatement(labeled_stmt) => { Statement::LabeledStatement(labeled_stmt) => {
Self::is_fusable_control_statement(&labeled_stmt.body) Self::is_fusable_control_statement(&labeled_stmt.body)
} }
@ -287,7 +289,7 @@ mod test {
// Never fuse a statement into a block that contains let/const/class declarations, or you risk // Never fuse a statement into a block that contains let/const/class declarations, or you risk
// colliding variable names. (unless the AST is normalized). // colliding variable names. (unless the AST is normalized).
test("a; {b;}", "a,b"); test("a; {b;}", "a,b");
test("a; {b; var a = 1;}", "{a,b; var a = 1;}"); test("a; {b; var a = 1;}", "{b; var a = 1;}");
test_same("a; { b; let a = 1; }"); test_same("a; { b; let a = 1; }");
test_same("a; { b; const a = 1; }"); test_same("a; { b; const a = 1; }");
test_same("a; { b; class a {} }"); test_same("a; { b; class a {} }");

10
crates/oxc_minifier/src/peephole/substitute_alternate_syntax.rs
View file

@ -1,9 +1,7 @@
use oxc_allocator::{CloneIn, Vec}; use oxc_allocator::{CloneIn, Vec};
use oxc_ast::{ast::*, NONE}; use oxc_ast::{ast::*, NONE};
use oxc_ecmascript::{ use oxc_ecmascript::{
constant_evaluation::{ConstantEvaluation, ValueType}, constant_evaluation::ValueType, side_effects::MayHaveSideEffects, ToJsString, ToNumber,
side_effects::MayHaveSideEffects,
ToJsString, ToNumber,
}; };
use oxc_span::GetSpan; use oxc_span::GetSpan;
use oxc_span::SPAN; use oxc_span::SPAN;
@ -455,7 +453,9 @@ impl<'a> PeepholeOptimizations {
let Some(argument) = &stmt.argument else { return }; let Some(argument) = &stmt.argument else { return };
if !match argument { if !match argument {
Expression::Identifier(ident) => Ctx(ctx).is_identifier_undefined(ident), Expression::Identifier(ident) => Ctx(ctx).is_identifier_undefined(ident),
Expression::UnaryExpression(e) => e.operator.is_void() && !e.may_have_side_effects(), Expression::UnaryExpression(e) => {
e.operator.is_void() && !Ctx(ctx).expression_may_have_side_efffects(argument)
}
_ => false, _ => false,
} { } {
return; return;
@ -1439,7 +1439,7 @@ mod test {
#[test] #[test]
fn test_fold_arrow_function_return() { fn test_fold_arrow_function_return() {
test("const foo = () => { return 'baz' }", "const foo = () => 'baz'"); test("const foo = () => { return 'baz' }", "const foo = () => 'baz'");
test("const foo = () => { foo; return 'baz' }", "const foo = () => (foo, 'baz');"); test("const foo = () => { foo; return 'baz' }", "const foo = () => 'baz'");
} }
#[test] #[test]

6
tasks/minsize/minsize.snap
View file

@ -3,7 +3,7 @@ Original | minified | minified | gzip | gzip | Fixture
------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------
72.14 kB | 23.61 kB | 23.70 kB | 8.55 kB | 8.54 kB | react.development.js 72.14 kB | 23.61 kB | 23.70 kB | 8.55 kB | 8.54 kB | react.development.js
173.90 kB | 59.71 kB | 59.82 kB | 19.26 kB | 19.33 kB | moment.js 173.90 kB | 59.69 kB | 59.82 kB | 19.26 kB | 19.33 kB | moment.js
287.63 kB | 89.58 kB | 90.07 kB | 31.08 kB | 31.95 kB | jquery.js 287.63 kB | 89.58 kB | 90.07 kB | 31.08 kB | 31.95 kB | jquery.js
@ -19,9 +19,9 @@ Original | minified | minified | gzip | gzip | Fixture
2.14 MB | 719.54 kB | 724.14 kB | 162.47 kB | 181.07 kB | victory.js 2.14 MB | 719.54 kB | 724.14 kB | 162.47 kB | 181.07 kB | victory.js
3.20 MB | 1.01 MB | 1.01 MB | 325.40 kB | 331.56 kB | echarts.js 3.20 MB | 1.01 MB | 1.01 MB | 325.41 kB | 331.56 kB | echarts.js
6.69 MB | 2.30 MB | 2.31 MB | 470.00 kB | 488.28 kB | antd.js 6.69 MB | 2.30 MB | 2.31 MB | 470.00 kB | 488.28 kB | antd.js
10.95 MB | 3.37 MB | 3.49 MB | 866.68 kB | 915.50 kB | typescript.js 10.95 MB | 3.37 MB | 3.49 MB | 866.65 kB | 915.50 kB | typescript.js