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feat(minifier): improve folding block stmts (#6793)

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This commit is contained in:
camc314 2024-10-23 04:13:57 +00:00
parent 7c51b2fd9d
commit b4bc300ebf
2 changed files with 64 additions and 12 deletions
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70
crates/oxc_minifier/src/ast_passes/peephole_remove_dead_code.rs
View file

@ -146,7 +146,12 @@ impl<'a, 'b> PeepholeRemoveDeadCode {
return;
}
if block.body.len() == 0
&& (ctx.parent().is_block_statement() || ctx.parent().is_program())
&& (ctx.parent().is_while_statement()
|| ctx.parent().is_for_statement()
|| ctx.parent().is_for_in_statement()
|| ctx.parent().is_for_of_statement()
|| ctx.parent().is_block_statement()
|| ctx.parent().is_program())
{
// Remove the block if it is empty and the parent is a block statement.
*stmt = ctx.ast.statement_empty(SPAN);
@ -282,6 +287,53 @@ impl<'a, 'b> PeepholeRemoveDeadCode {
Expression::ObjectExpression(object_expr) => {
Self::try_fold_object_expression(object_expr, ctx)
}
Expression::TemplateLiteral(template_lit) => {
template_lit.expressions.retain(
oxc_ecmascript::side_effects::MayHaveSideEffects::may_have_side_effects,
);
let mut expressions = ctx.ast.move_vec(&mut template_lit.expressions);
if expressions.len() == 0 {
return Some(ctx.ast.statement_empty(SPAN));
} else if expressions.len() == 1 {
return Some(
ctx.ast.statement_expression(
template_lit.span,
expressions.pop().unwrap(),
),
);
}
return Some(ctx.ast.statement_expression(
template_lit.span,
ctx.ast.expression_from_sequence(
ctx.ast.sequence_expression(template_lit.span, expressions),
),
));
}
Expression::BinaryExpression(bin_expr) => {
let left = bin_expr.left.may_have_side_effects();
let right = bin_expr.left.may_have_side_effects();
if left && right {
return None;
}
if !left && !right {
return Some(ctx.ast.statement_empty(SPAN));
}
return Some(ctx.ast.statement_expression(
bin_expr.span,
ctx.ast.move_expression(if left {
&mut bin_expr.right
} else {
&mut bin_expr.left
}),
));
}
Expression::FunctionExpression(function_expr) if function_expr.id.is_none() => {
Some(ctx.ast.statement_empty(SPAN))
}
_ => None,
})
}
@ -503,22 +555,22 @@ mod test {
fold("{if(false)if(false)if(false)foo(); {bar()}}", "bar()");
fold("{'hi'}", "");
// fold("{x==3}", "");
// fold("{`hello ${foo}`}", "");
// fold("{ (function(){x++}) }", "");
// fold_same("function f(){return;}");
// fold("function f(){return 3;}", "function f(){return 3}");
fold("{x==3}", "");
fold("{`hello ${foo}`}", "");
fold("{ (function(){x++}) }", "");
fold_same("function f(){return;}");
fold("function f(){return 3;}", "function f(){return 3}");
// fold_same("function f(){if(x)return; x=3; return; }");
// fold("{x=3;;;y=2;;;}", "x=3;y=2");
// Cases to test for empty block.
// fold("while(x()){x}", "while(x());");
// fold("while(x()){x()}", "while(x())x()");
fold("while(x()){x()}", "while(x())x()");
// fold("for(x=0;x<100;x++){x}", "for(x=0;x<100;x++);");
// fold("for(x in y){x}", "for(x in y);");
// fold("for (x of y) {x}", "for(x of y);");
// fold_same("for (let x = 1; x <10; x++ ) {}");
// fold_same("for (var x = 1; x <10; x++ ) {}");
fold("for (let x = 1; x <10; x++ ) {}", "for (let x = 1; x <10; x++ );");
fold("for (var x = 1; x <10; x++ ) {}", "for (var x = 1; x <10; x++ );");
}
#[test]

6
tasks/minsize/minsize.snap
View file

@ -4,11 +4,11 @@ Original | Minified | esbuild | Gzip | esbuild
173.90 kB | 61.67 kB | 59.82 kB | 19.54 kB | 19.33 kB | moment.js
287.63 kB | 92.70 kB | 90.07 kB | 32.27 kB | 31.95 kB | jquery.js
287.63 kB | 92.70 kB | 90.07 kB | 32.26 kB | 31.95 kB | jquery.js
342.15 kB | 121.90 kB | 118.14 kB | 44.59 kB | 44.37 kB | vue.js
544.10 kB | 73.49 kB | 72.48 kB | 26.13 kB | 26.20 kB | lodash.js
544.10 kB | 73.48 kB | 72.48 kB | 26.12 kB | 26.20 kB | lodash.js
555.77 kB | 276.49 kB | 270.13 kB | 91.15 kB | 90.80 kB | d3.js
@ -16,7 +16,7 @@ Original | Minified | esbuild | Gzip | esbuild
1.25 MB | 662.86 kB | 646.76 kB | 164.00 kB | 163.73 kB | three.js
2.14 MB | 741.57 kB | 724.14 kB | 181.47 kB | 181.07 kB | victory.js
2.14 MB | 741.57 kB | 724.14 kB | 181.45 kB | 181.07 kB | victory.js
3.20 MB | 1.02 MB | 1.01 MB | 332.01 kB | 331.56 kB | echarts.js