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feat(es/minifier): Handle prefix update expressions with sequential inliner (#4741)

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Donny/강동윤 2022-05-23 13:29:31 +09:00 committed by GitHub
parent 516b0b804b
commit a51816a577
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3 changed files with 136 additions and 62 deletions
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196
crates/swc_ecma_minifier/src/compress/optimize/sequences.rs
View File

@ -1618,79 +1618,153 @@ where
fn replace_seq_update(&mut self, a: &mut Mergable, b: &mut Expr) -> Result<bool, ()> {
if let Mergable::Expr(a) = a {
if let Expr::Update(UpdateExpr {
op,
prefix: false,
arg,
..
}) = *a
{
if let Expr::Ident(a_id) = &**arg {
if let Some(usage) = self.data.vars.get(&a_id.to_id()) {
if let Some(VarDeclKind::Const) = usage.var_kind {
return Err(());
}
}
let mut v = UsageCounter {
expr_usage: Default::default(),
pat_usage: Default::default(),
target: &*a_id,
in_lhs: false,
};
b.visit_with(&mut v);
if v.expr_usage != 1 || v.pat_usage != 0 {
log_abort!(
"sequences: Aborting merging of an update expression because of usage \
counts ({}, ref = {}, pat = {})",
a_id,
v.expr_usage,
v.pat_usage
);
return Ok(false);
}
let mut replaced = false;
replace_expr(b, |e| {
if replaced {
return;
match a {
Expr::Update(UpdateExpr {
op,
prefix: false,
arg,
..
}) => {
if let Expr::Ident(a_id) = &**arg {
if let Some(usage) = self.data.vars.get(&a_id.to_id()) {
if let Some(VarDeclKind::Const) = usage.var_kind {
return Err(());
}
}
if let Expr::Ident(orig_expr) = &*e {
if orig_expr.to_id() == a_id.to_id() {
replaced = true;
*e = Expr::Update(UpdateExpr {
span: DUMMY_SP,
op: *op,
prefix: true,
arg: Box::new(Expr::Ident(orig_expr.clone())),
});
let mut v = UsageCounter {
expr_usage: Default::default(),
pat_usage: Default::default(),
target: &*a_id,
in_lhs: false,
};
b.visit_with(&mut v);
if v.expr_usage != 1 || v.pat_usage != 0 {
log_abort!(
"sequences: Aborting merging of an update expression because of \
usage counts ({}, ref = {}, pat = {})",
a_id,
v.expr_usage,
v.pat_usage
);
return Ok(false);
}
let mut replaced = false;
replace_expr(b, |e| {
if replaced {
return;
}
}
if let Expr::Update(e @ UpdateExpr { prefix: false, .. }) = e {
if let Expr::Ident(arg) = &*e.arg {
if *op == e.op && arg.to_id() == a_id.to_id() {
e.prefix = true;
if let Expr::Ident(orig_expr) = &*e {
if orig_expr.to_id() == a_id.to_id() {
replaced = true;
*e = Expr::Update(UpdateExpr {
span: DUMMY_SP,
op: *op,
prefix: true,
arg: Box::new(Expr::Ident(orig_expr.clone())),
});
return;
}
}
}
});
if replaced {
self.changed = true;
report_change!(
"sequences: Merged update expression into another expression",
);
a.take();
return Ok(true);
if let Expr::Update(e @ UpdateExpr { prefix: false, .. }) = e {
if let Expr::Ident(arg) = &*e.arg {
if *op == e.op && arg.to_id() == a_id.to_id() {
e.prefix = true;
replaced = true;
}
}
}
});
if replaced {
self.changed = true;
report_change!(
"sequences: Merged update expression into another expression",
);
a.take();
return Ok(true);
}
}
}
return Ok(false);
Expr::Update(UpdateExpr {
op,
prefix: true,
arg,
..
}) => {
if let Expr::Ident(a_id) = &**arg {
if let Some(usage) = self.data.vars.get(&a_id.to_id()) {
if let Some(VarDeclKind::Const) = usage.var_kind {
return Err(());
}
}
let mut v = UsageCounter {
expr_usage: Default::default(),
pat_usage: Default::default(),
target: &*a_id,
in_lhs: false,
};
b.visit_with(&mut v);
if v.expr_usage != 1 || v.pat_usage != 0 {
log_abort!(
"sequences: Aborting merging of an update expression because of \
usage counts ({}, ref = {}, pat = {})",
a_id,
v.expr_usage,
v.pat_usage
);
return Ok(false);
}
let mut replaced = false;
replace_expr(b, |e| {
if replaced {
return;
}
if let Expr::Ident(orig_expr) = &*e {
if orig_expr.to_id() == a_id.to_id() {
replaced = true;
*e = Expr::Update(UpdateExpr {
span: DUMMY_SP,
op: *op,
prefix: true,
arg: Box::new(Expr::Ident(orig_expr.clone())),
});
return;
}
}
if let Expr::Update(e @ UpdateExpr { prefix: false, .. }) = e {
if let Expr::Ident(arg) = &*e.arg {
if *op == e.op && arg.to_id() == a_id.to_id() {
e.prefix = true;
replaced = true;
}
}
}
});
if replaced {
self.changed = true;
report_change!(
"sequences: Merged prefix update expression into another \
expression",
);
a.take();
return Ok(true);
}
}
}
_ => {}
}
}

1
crates/swc_ecma_minifier/tests/golden.txt
View File

@ -211,6 +211,7 @@ collapse_vars/issue_3096/input.js
collapse_vars/issue_348/input.js
collapse_vars/issue_805/input.js
collapse_vars/may_throw_1/input.js
collapse_vars/may_throw_2/input.js
collapse_vars/modified/input.js
collapse_vars/reassign_const_1/input.js
collapse_vars/reassign_const_2/input.js

1
crates/swc_ecma_minifier/tests/postponed.txt
View File

@ -81,7 +81,6 @@ collapse_vars/issue_2506/input.js
collapse_vars/issue_2914_2/input.js
collapse_vars/issue_315/input.js
collapse_vars/lvalues_def/input.js
collapse_vars/may_throw_2/input.js
collapse_vars/noinline_annotation/input.js
collapse_vars/pure_getters_chain/input.js
collapse_vars/recursive_function_replacement/input.js