lib: generate allowedNodeEnvironmentFlags lazily

Backport-PR-URL: #22847
PR-URL: #22638
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: addaleax

lib/internal/bootstrap/node.js

@@ -619,117 +619,132 @@
 consthas=Function.call.bind(Set.prototype.has);
 consttest=Function.call.bind(RegExp.prototype.test);
 
-const{
- getOptions,
-types: { kV8Option },
-envSettings: { kAllowedInEnvironment }
-}=internalBinding('options');
-const{ options, aliases }=getOptions();
-
-constallowedV8EnvironmentFlags=[];
-constallowedNodeEnvironmentFlags=[];
-for(const[name,info]ofoptions){
-if(info.envVarSettings===kAllowedInEnvironment){
-if(info.type===kV8Option){
-allowedV8EnvironmentFlags.push(name);
-}else{
-allowedNodeEnvironmentFlags.push(name);
+constget=()=>{
+const{
+ getOptions,
+types: { kV8Option },
+envSettings: { kAllowedInEnvironment }
+}=internalBinding('options');
+const{ options, aliases }=getOptions();
+
+constallowedV8EnvironmentFlags=[];
+constallowedNodeEnvironmentFlags=[];
+for(const[name,info]ofoptions){
+if(info.envVarSettings===kAllowedInEnvironment){
+if(info.type===kV8Option){
+allowedV8EnvironmentFlags.push(name);
+}else{
+allowedNodeEnvironmentFlags.push(name);
+}
 }
 }
-}
 
-for(const[from,expansion]ofaliases){
-letisAccepted=true;
-for(consttoofexpansion){
-if(!to.startsWith('-'))continue;
-constrecursiveExpansion=aliases.get(to);
-if(recursiveExpansion){
-expansion.push(...recursiveExpansion);
-continue;
+for(const[from,expansion]ofaliases){
+letisAccepted=true;
+for(consttoofexpansion){
+if(!to.startsWith('-'))continue;
+constrecursiveExpansion=aliases.get(to);
+if(recursiveExpansion){
+expansion.push(...recursiveExpansion);
+continue;
+}
+isAccepted=options.get(to).envVarSettings===kAllowedInEnvironment;
+if(!isAccepted)break;
+}
+if(isAccepted){
+letcanonical=from;
+if(canonical.endsWith('='))
+canonical=canonical.substr(0,canonical.length-1);
+if(canonical.endsWith(' <arg>'))
+canonical=canonical.substr(0,canonical.length-4);
+allowedNodeEnvironmentFlags.push(canonical);
 }
-isAccepted=options.get(to).envVarSettings===kAllowedInEnvironment;
-if(!isAccepted)break;
-}
-if(isAccepted){
-letcanonical=from;
-if(canonical.endsWith('='))
-canonical=canonical.substr(0,canonical.length-1);
-if(canonical.endsWith(' <arg>'))
-canonical=canonical.substr(0,canonical.length-4);
-allowedNodeEnvironmentFlags.push(canonical);
 }
-}
 
-consttrimLeadingDashes=(flag)=>replace(flag,leadingDashesRegex,'');
-
-// Save these for comparison against flags provided to
-// process.allowedNodeEnvironmentFlags.has() which lack leading dashes.
-// Avoid interference w/ user code by flattening `Set.prototype` into
-// each object.
-const[nodeFlags,v8Flags]=[
-allowedNodeEnvironmentFlags,allowedV8EnvironmentFlags
-].map((flags)=>Object.defineProperties(
-newSet(flags.map(trimLeadingDashes)),
-Object.getOwnPropertyDescriptors(Set.prototype))
-);
-
-classNodeEnvironmentFlagsSetextendsSet{
-constructor(...args){
-super(...args);
-
-// the super constructor consumes `add`, but
-// disallow any future adds.
-this.add=()=>this;
-}
+consttrimLeadingDashes=(flag)=>replace(flag,leadingDashesRegex,'');
+
+// Save these for comparison against flags provided to
+// process.allowedNodeEnvironmentFlags.has() which lack leading dashes.
+// Avoid interference w/ user code by flattening `Set.prototype` into
+// each object.
+const[nodeFlags,v8Flags]=[
+allowedNodeEnvironmentFlags,allowedV8EnvironmentFlags
+].map((flags)=>Object.defineProperties(
+newSet(flags.map(trimLeadingDashes)),
+Object.getOwnPropertyDescriptors(Set.prototype))
+);
 
-delete(){
-// noop, `Set` API compatible
-returnfalse;
-}
+classNodeEnvironmentFlagsSetextendsSet{
+constructor(...args){
+super(...args);
 
-clear(){
-// noop
-}
+// the super constructor consumes `add`, but
+// disallow any future adds.
+this.add=()=>this;
+}
 
-has(key){
-// This will return `true` based on various possible
-// permutations of a flag, including present/missing leading
-// dash(es) and/or underscores-for-dashes in the case of V8-specific
-// flags. Strips any values after `=`, inclusive.
-// TODO(addaleax): It might be more flexible to run the option parser
-// on a dummy option set and see whether it rejects the argument or
-// not.
-if(typeofkey==='string'){
-key=replace(key,trailingValuesRegex,'');
-if(test(leadingDashesRegex,key)){
-returnhas(this,key)||
-has(v8Flags,
-replace(
+delete(){
+// noop, `Set` API compatible
+returnfalse;
+}
+
+clear(){
+// noop
+}
+
+has(key){
+// This will return `true` based on various possible
+// permutations of a flag, including present/missing leading
+// dash(es) and/or underscores-for-dashes in the case of V8-specific
+// flags. Strips any values after `=`, inclusive.
+// TODO(addaleax): It might be more flexible to run the option parser
+// on a dummy option set and see whether it rejects the argument or
+// not.
+if(typeofkey==='string'){
+key=replace(key,trailingValuesRegex,'');
+if(test(leadingDashesRegex,key)){
+returnhas(this,key)||
+has(v8Flags,
 replace(
-key,
-leadingDashesRegex,
-''
-),
-replaceDashesRegex,
-'_'
-)
-);
+replace(
+key,
+leadingDashesRegex,
+''
+),
+replaceDashesRegex,
+'_'
+)
+);
+}
+returnhas(nodeFlags,key)||
+has(v8Flags,replace(key,replaceDashesRegex,'_'));
 }
-returnhas(nodeFlags,key)||
-has(v8Flags,replace(key,replaceDashesRegex,'_'));
+returnfalse;
 }
-returnfalse;
 }
-}
 
-Object.freeze(NodeEnvironmentFlagsSet.prototype.constructor);
-Object.freeze(NodeEnvironmentFlagsSet.prototype);
+Object.freeze(NodeEnvironmentFlagsSet.prototype.constructor);
+Object.freeze(NodeEnvironmentFlagsSet.prototype);
+
+returnprocess.allowedNodeEnvironmentFlags=Object.freeze(
+newNodeEnvironmentFlagsSet(
+allowedNodeEnvironmentFlags.concat(allowedV8EnvironmentFlags)
+));
+};
 
-process.allowedNodeEnvironmentFlags=Object.freeze(
-newNodeEnvironmentFlagsSet(
-allowedNodeEnvironmentFlags.concat(allowedV8EnvironmentFlags)
-)
-);
+Object.defineProperty(process,'allowedNodeEnvironmentFlags',{
+ get,
+set(value){
+Object.defineProperty(this,'allowedNodeEnvironmentFlags',{
+ value,
+configurable: true,
+enumerable: true,
+writable: true
+});
+},
+enumerable: true,
+configurable: true
+});
 }
 
 startup();