fix some generated temporary use counts

evanw · Apr 2, 2022 · c9e2fdb · c9e2fdb
1 parent e16cde0
commit c9e2fdb
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Showing 2 changed files with 14 additions and 5 deletions.
diff --git a/internal/js_parser/js_parser.go b/internal/js_parser/js_parser.go
@@ -7303,14 +7303,16 @@ func (p *parser) visitStmtsAndPrependTempRefs(stmts []js_ast.Stmt, opts prependT
 	}
 
 	// Prepend the generated temporary variables to the beginning of the statement list
-	if len(p.tempRefsToDeclare) > 0 {
-		decls := []js_ast.Decl{}
-		for _, temp := range p.tempRefsToDeclare {
+	decls := []js_ast.Decl{}
+	for _, temp := range p.tempRefsToDeclare {
+		if p.symbols[temp.ref.InnerIndex].UseCountEstimate > 0 {
 			decls = append(decls, js_ast.Decl{Binding: js_ast.Binding{Data: &js_ast.BIdentifier{Ref: temp.ref}}, ValueOrNil: temp.valueOrNil})
 			p.recordDeclaredSymbol(temp.ref)
 		}
+	}
 
-		// If the first statement is a super() call, make sure it stays that way
+	// If the first statement is a super() call, make sure it stays that way
+	if len(decls) > 0 {
 		stmt := js_ast.Stmt{Data: &js_ast.SLocal{Kind: js_ast.LocalVar, Decls: decls}}
 		if len(stmts) > 0 && js_ast.IsSuperCall(stmts[0]) {
 			stmts = append([]js_ast.Stmt{stmts[0], stmt}, stmts[1:]...)
@@ -13720,7 +13722,9 @@ func (p *parser) handleIdentifier(loc logger.Loc, e *js_ast.EIdentifier, opts id
 		isInsideUnsupportedArrow := p.fnOrArrowDataVisit.isArrow && p.options.unsupportedJSFeatures.Has(compat.Arrow)
 		isInsideUnsupportedAsyncArrow := p.fnOnlyDataVisit.isInsideAsyncArrowFn && p.options.unsupportedJSFeatures.Has(compat.AsyncAwait)
 		if isInsideUnsupportedArrow || isInsideUnsupportedAsyncArrow {
-			return js_ast.Expr{Loc: loc, Data: &js_ast.EIdentifier{Ref: p.captureArguments()}}
+			argumentsRef := p.captureArguments()
+			p.recordUsage(argumentsRef)
+			return js_ast.Expr{Loc: loc, Data: &js_ast.EIdentifier{Ref: argumentsRef}}
 		}
 	}
 

diff --git a/internal/js_parser/js_parser_lower.go b/internal/js_parser/js_parser_lower.go
@@ -1300,6 +1300,7 @@ func (p *parser) lowerObjectRestInForLoopInit(init js_ast.Stmt, body *js_ast.Stm
 		if exprHasObjectRest(s.Value) {
 			ref := p.generateTempRef(tempRefNeedsDeclare, "")
 			if expr, ok := p.lowerAssign(s.Value, js_ast.Expr{Loc: init.Loc, Data: &js_ast.EIdentifier{Ref: ref}}, objRestReturnValueIsUnused); ok {
+				p.recordUsage(ref)
 				s.Value.Data = &js_ast.EIdentifier{Ref: ref}
 				bodyPrefixStmt = js_ast.Stmt{Loc: expr.Loc, Data: &js_ast.SExpr{Value: expr}}
 			}
@@ -2213,6 +2214,7 @@ func (p *parser) lowerClass(stmt js_ast.Stmt, expr js_ast.Expr, shadowRef js_ast
 			} else if _, ok := prop.Key.Data.(*js_ast.EString); !ok {
 				// Store the key in a temporary so we can assign to it later
 				ref := p.generateTempRef(tempRefNeedsDeclare, "")
+				p.recordUsage(ref)
 				computedPropertyCache = js_ast.JoinWithComma(computedPropertyCache,
 					js_ast.Assign(js_ast.Expr{Loc: prop.Key.Loc, Data: &js_ast.EIdentifier{Ref: ref}}, prop.Key))
 				prop.Key = js_ast.Expr{Loc: prop.Key.Loc, Data: &js_ast.EIdentifier{Ref: ref}}
@@ -2429,6 +2431,7 @@ func (p *parser) lowerClass(stmt js_ast.Stmt, expr js_ast.Expr, shadowRef js_ast
 				} else {
 					p.symbols[methodRef.InnerIndex].Link = p.privateGetters[private.Ref]
 				}
+				p.recordUsage(methodRef)
 				privateMembers = append(privateMembers, js_ast.Assign(
 					js_ast.Expr{Loc: loc, Data: &js_ast.EIdentifier{Ref: methodRef}},
 					prop.ValueOrNil,
@@ -2815,6 +2818,8 @@ func (p *parser) lowerTemplateLiteral(loc logger.Loc, e *js_ast.ETemplate) js_as
 
 	// Cache it in a temporary object (required by the specification)
 	tempRef := p.generateTopLevelTempRef()
+	p.recordUsage(tempRef)
+	p.recordUsage(tempRef)
 	args[0] = js_ast.Expr{Loc: loc, Data: &js_ast.EBinary{
 		Op:   js_ast.BinOpLogicalOr,
 		Left: js_ast.Expr{Loc: loc, Data: &js_ast.EIdentifier{Ref: tempRef}},