switch define data to flags

Author: evanw

internal/bundler_tests/bundler_dce_test.go

@@ -1273,8 +1273,8 @@ func TestTreeShakingReactElements(t *testing.T) {
 
 func TestDisableTreeShaking(t *testing.T) {
 	defines := config.ProcessDefines(map[string]config.DefineData{
-		"pure":    {CallCanBeUnwrappedIfUnused: true},
-		"some.fn": {CallCanBeUnwrappedIfUnused: true},
+		"pure":    {Flags: config.CallCanBeUnwrappedIfUnused},
+		"some.fn": {Flags: config.CallCanBeUnwrappedIfUnused},
 	})
 	dce_suite.expectBundled(t, bundled{
 		files: map[string]string{

internal/config/globals.go

@@ -869,31 +869,35 @@ type DefineExpr struct {
 
 type DefineData struct {
 	DefineExpr *DefineExpr
+	Flags      DefineFlags
+}
+
+type DefineFlags uint8
 
+const (
 	// True if accessing this value is known to not have any side effects. For
 	// example, a bare reference to "Object.create" can be removed because it
 	// does not have any observable side effects.
-	CanBeRemovedIfUnused bool
+	CanBeRemovedIfUnused DefineFlags = 1 << iota
 
 	// True if a call to this value is known to not have any side effects. For
 	// example, a bare call to "Object()" can be removed because it does not
 	// have any observable side effects.
-	CallCanBeUnwrappedIfUnused bool
+	CallCanBeUnwrappedIfUnused
 
 	// If true, the user has indicated that every direct calls to a property on
 	// this object and all of that call's arguments are to be removed from the
 	// output, even when the arguments have side effects. This is used to
 	// implement the "--drop:console" flag.
-	MethodCallsMustBeReplacedWithUndefined bool
+	MethodCallsMustBeReplacedWithUndefined
+)
+
+func (flags DefineFlags) Has(flag DefineFlags) bool {
+	return (flags & flag) != 0
 }
 
 func mergeDefineData(old DefineData, new DefineData) DefineData {
-	if old.CanBeRemovedIfUnused {
-		new.CanBeRemovedIfUnused = true
-	}
-	if old.CallCanBeUnwrappedIfUnused {
-		new.CallCanBeUnwrappedIfUnused = true
-	}
+	new.Flags |= old.Flags
 	return new
 }
 
@@ -937,9 +941,9 @@ func ProcessDefines(userDefines map[string]DefineData) ProcessedDefines {
 	for _, parts := range knownGlobals {
 		tail := parts[len(parts)-1]
 		if len(parts) == 1 {
-			result.IdentifierDefines[tail] = DefineData{CanBeRemovedIfUnused: true}
+			result.IdentifierDefines[tail] = DefineData{Flags: CanBeRemovedIfUnused}
 		} else {
-			result.DotDefines[tail] = append(result.DotDefines[tail], DotDefine{Parts: parts, Data: DefineData{CanBeRemovedIfUnused: true}})
+			result.DotDefines[tail] = append(result.DotDefines[tail], DotDefine{Parts: parts, Data: DefineData{Flags: CanBeRemovedIfUnused}})
 		}
 	}
 

internal/js_parser/js_parser.go

@@ -12880,13 +12880,13 @@ func (p *parser) visitExprInOut(expr js_ast.Expr, in exprIn) (js_ast.Expr, exprO
 				}
 
 				// Copy the side effect flags over in case this expression is unused
-				if data.CanBeRemovedIfUnused {
+				if data.Flags.Has(config.CanBeRemovedIfUnused) {
 					e.CanBeRemovedIfUnused = true
 				}
-				if data.CallCanBeUnwrappedIfUnused && !p.options.ignoreDCEAnnotations {
+				if data.Flags.Has(config.CallCanBeUnwrappedIfUnused) && !p.options.ignoreDCEAnnotations {
 					e.CallCanBeUnwrappedIfUnused = true
 				}
-				if data.MethodCallsMustBeReplacedWithUndefined {
+				if data.Flags.Has(config.MethodCallsMustBeReplacedWithUndefined) {
 					methodCallMustBeReplacedWithUndefined = true
 				}
 			}
@@ -13406,10 +13406,10 @@ func (p *parser) visitExprInOut(expr js_ast.Expr, in exprIn) (js_ast.Expr, exprO
 					}
 
 					// Copy the side effect flags over in case this expression is unused
-					if define.Data.CanBeRemovedIfUnused {
+					if define.Data.Flags.Has(config.CanBeRemovedIfUnused) {
 						e.CanBeRemovedIfUnused = true
 					}
-					if define.Data.CallCanBeUnwrappedIfUnused && !p.options.ignoreDCEAnnotations {
+					if define.Data.Flags.Has(config.CallCanBeUnwrappedIfUnused) && !p.options.ignoreDCEAnnotations {
 						e.CallCanBeUnwrappedIfUnused = true
 					}
 					break
@@ -13529,10 +13529,10 @@ func (p *parser) visitExprInOut(expr js_ast.Expr, in exprIn) (js_ast.Expr, exprO
 						}
 
 						// Copy the side effect flags over in case this expression is unused
-						if define.Data.CanBeRemovedIfUnused {
+						if define.Data.Flags.Has(config.CanBeRemovedIfUnused) {
 							e.CanBeRemovedIfUnused = true
 						}
-						if define.Data.CallCanBeUnwrappedIfUnused && !p.options.ignoreDCEAnnotations {
+						if define.Data.Flags.Has(config.CallCanBeUnwrappedIfUnused) && !p.options.ignoreDCEAnnotations {
 							e.CallCanBeUnwrappedIfUnused = true
 						}
 						break

pkg/api/api_impl.go

@@ -694,7 +694,7 @@ func validateDefines(
 	// If we're dropping all console API calls, replace each one with undefined
 	if (drop & DropConsole) != 0 {
 		define := rawDefines["console"]
-		define.MethodCallsMustBeReplacedWithUndefined = true
+		define.Flags |= config.MethodCallsMustBeReplacedWithUndefined
 		rawDefines["console"] = define
 	}
 
@@ -709,7 +709,7 @@ func validateDefines(
 
 		// Merge with any previously-specified defines
 		define := rawDefines[key]
-		define.CallCanBeUnwrappedIfUnused = true
+		define.Flags |= config.CallCanBeUnwrappedIfUnused
 		rawDefines[key] = define
 	}