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refactor(es/minifier): Decouple assign_count from reassigned (#8137)

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Austaras 2023-10-20 03:37:37 +08:00 committed by GitHub
parent a18ffc107f
commit 13106e0d2e
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5 changed files with 35 additions and 39 deletions
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4
crates/swc_ecma_minifier/src/compress/optimize/inline.rs
View File

@ -174,7 +174,7 @@ impl Optimizer<'_> {
// new variant is added for multi inline, think carefully
if is_inline_enabled
&& usage.declared_count == 1
&& usage.assign_count == 0
&& usage.assign_count == 1
&& (!usage.has_property_mutation || !usage.reassigned)
&& match init {
Expr::Ident(Ident { sym, .. }) if &**sym == "eval" => false,
@ -326,7 +326,7 @@ impl Optimizer<'_> {
&& usage.declared
&& may_remove
&& !usage.reassigned
&& usage.assign_count == 0
&& usage.assign_count == 1
&& ref_count == 1
{
match init {

3
crates/swc_ecma_minifier/src/compress/optimize/sequences.rs
View File

@ -2327,8 +2327,7 @@ impl Optimizer<'_> {
if let Some(usage) = self.data.vars.get(&left_id.to_id()) {
// We are eliminating one usage, so we use 1 instead of
// 0
if !$force_drop && usage.usage_count == 1 && usage.assign_count == 0
{
if !$force_drop && usage.usage_count == 1 && !usage.reassigned {
report_change!("sequences: Dropping inlined variable");
a.name.take();
}

43
crates/swc_ecma_minifier/src/program_data.rs
View File

@ -64,6 +64,7 @@ pub(crate) struct VarUsageInfo {
pub(crate) declared_as_for_init: bool,
/// The number of assign and initialization to this identifier.
pub(crate) assign_count: u32,
/// The number of direct and indirect reference to this identifier.
@ -171,7 +172,7 @@ impl VarUsageInfo {
/// The variable itself or a property of it is modified.
pub(crate) fn mutated(&self) -> bool {
self.assign_count > 0 || self.has_property_mutation
self.assign_count > 1 || self.has_property_mutation
}
pub(crate) fn can_inline_fn_once(&self) -> bool {
@ -221,11 +222,16 @@ impl Storage for ProgramData {
let var_assigned = var_info.assign_count > 0
|| (var_info.var_initialized && !e.get().var_initialized);
if var_info.assign_count > 0 {
if e.get().initialized() {
e.get_mut().reassigned = true
}
}
if var_info.var_initialized {
// If it is inited in some other child scope and also inited in current
// scope
if e.get().var_initialized || e.get().ref_count > 0 {
e.get_mut().assign_count += 1;
e.get_mut().reassigned = true;
} else {
// If it is referred outside child scope, it will
@ -237,7 +243,6 @@ impl Storage for ProgramData {
// current child scope
if !inited && e.get().var_initialized && var_info.ref_count > 0 {
e.get_mut().var_initialized = false;
e.get_mut().assign_count += 1;
e.get_mut().reassigned = true
}
}
@ -246,12 +251,6 @@ impl Storage for ProgramData {
e.get_mut().reassigned |= var_info.reassigned;
if var_info.assign_count > 0 {
if e.get().initialized() {
e.get_mut().reassigned = true
}
}
e.get_mut().has_property_access |= var_info.has_property_access;
e.get_mut().has_property_mutation |= var_info.has_property_mutation;
e.get_mut().exported |= var_info.exported;
@ -349,13 +348,16 @@ impl Storage for ProgramData {
v.is_top_level |= ctx.is_top_level;
// assigned or declared before this declaration
if has_init && (v.declared || v.var_initialized || v.assign_count > 0) {
#[cfg(feature = "debug")]
{
tracing::trace!("declare_decl(`{}`): Already declared", i);
if has_init {
if v.declared || v.var_initialized || v.assign_count > 0 {
#[cfg(feature = "debug")]
{
tracing::trace!("declare_decl(`{}`): Already declared", i);
}
v.reassigned = true;
}
v.reassigned = true;
v.assign_count += 1;
}
@ -403,7 +405,7 @@ impl Storage for ProgramData {
for other in to_mark_mutate {
let other = self.vars.entry(other).or_insert_with(|| {
let simple_assign = ctx.is_exact_reassignment && !ctx.is_op_assign;
let simple_assign = ctx.is_exact_assignment && !ctx.is_op_assign;
VarUsageInfo {
used_above_decl: !simple_assign,
@ -570,7 +572,7 @@ impl ProgramData {
let e = self.vars.entry(i.clone()).or_insert_with(|| {
// trace!("insert({}{:?})", i.0, i.1);
let simple_assign = ctx.is_exact_reassignment && !ctx.is_op_assign;
let simple_assign = ctx.is_exact_assignment && !ctx.is_op_assign;
VarUsageInfo {
used_above_decl: !simple_assign,
@ -601,7 +603,7 @@ impl ProgramData {
e.executed_multiple_time |= ctx.executed_multiple_time;
e.used_in_cond |= ctx.in_cond;
if is_modify && ctx.is_exact_reassignment {
if is_modify && ctx.is_exact_assignment {
if is_first {
if e.assign_count > 0 || e.initialized() {
e.reassigned = true
@ -610,13 +612,8 @@ impl ProgramData {
e.assign_count += 1;
if !ctx.is_op_assign {
if e.ref_count == 1
&& ctx.in_assign_lhs
&& e.var_kind != Some(VarDeclKind::Const)
&& !inited
{
if e.ref_count == 1 && e.var_kind != Some(VarDeclKind::Const) && !inited {
self.initialized_vars.insert(i.clone());
e.assign_count -= 1;
e.var_initialized = true;
} else {
e.reassigned = true

2
crates/swc_ecma_usage_analyzer/src/analyzer/ctx.rs
View File

@ -112,7 +112,7 @@ pub struct Ctx {
pub in_pat_of_param: bool,
pub in_catch_param: bool,
/// `true` for `foo.bar` and `false` for `foo` in `foo.bar++`
pub is_exact_reassignment: bool,
pub is_exact_assignment: bool,
pub is_callee: bool,

22
crates/swc_ecma_usage_analyzer/src/analyzer/mod.rs
View File

@ -218,7 +218,7 @@ where
fn visit_assign_expr(&mut self, n: &AssignExpr) {
let ctx = Ctx {
in_assign_lhs: true,
is_exact_reassignment: true,
is_exact_assignment: true,
is_op_assign: n.op != op!("="),
is_delete_arg: false,
..self.ctx
@ -227,7 +227,7 @@ where
let ctx = Ctx {
in_assign_lhs: false,
is_exact_reassignment: false,
is_exact_assignment: false,
is_delete_arg: false,
// We mark bar in
//
@ -407,7 +407,7 @@ where
},
is_delete_arg: false,
is_exact_arg: true,
is_exact_reassignment: false,
is_exact_assignment: false,
is_callee: false,
is_id_ref: true,
..self.ctx
@ -750,7 +750,7 @@ where
self.with_child(n.span.ctxt, ScopeKind::Block, |child| {
let ctx = Ctx {
is_exact_reassignment: true,
is_exact_assignment: true,
is_delete_arg: false,
in_left_of_for_loop: true,
..child.ctx
@ -777,7 +777,7 @@ where
self.with_child(n.span.ctxt, ScopeKind::Block, |child| {
let ctx = Ctx {
in_left_of_for_loop: true,
is_exact_reassignment: true,
is_exact_assignment: true,
is_delete_arg: false,
..child.ctx
};
@ -884,7 +884,7 @@ where
{
let ctx = Ctx {
is_exact_arg: false,
is_exact_reassignment: false,
is_exact_assignment: false,
is_callee: false,
is_id_ref: false,
..self.ctx
@ -895,7 +895,7 @@ where
if let MemberProp::Computed(c) = &e.prop {
let ctx = Ctx {
is_exact_arg: false,
is_exact_reassignment: false,
is_exact_assignment: false,
is_callee: false,
is_delete_arg: false,
..self.ctx
@ -1067,7 +1067,7 @@ where
fn visit_prop(&mut self, n: &Prop) {
let ctx = Ctx {
is_exact_arg: false,
is_exact_reassignment: false,
is_exact_assignment: false,
is_id_ref: true,
..self.ctx
};
@ -1151,7 +1151,7 @@ where
if let SuperProp::Computed(c) = &e.prop {
let ctx = Ctx {
is_exact_arg: false,
is_exact_reassignment: false,
is_exact_assignment: false,
is_delete_arg: false,
is_id_ref: false,
..self.ctx
@ -1217,7 +1217,7 @@ where
fn visit_unary_expr(&mut self, n: &UnaryExpr) {
let ctx = Ctx {
in_update_arg: false,
is_exact_reassignment: false,
is_exact_assignment: false,
is_delete_arg: n.op == op!("delete"),
..self.ctx
};
@ -1228,7 +1228,7 @@ where
fn visit_update_expr(&mut self, n: &UpdateExpr) {
let ctx = Ctx {
in_update_arg: true,
is_exact_reassignment: true,
is_exact_assignment: true,
is_delete_arg: false,
..self.ctx
};