Check if intrinsic abstract values have unique names

Summary:
Fix for #1155
Closes https://github.com/facebook/prepack/pull/1197

Differential Revision: D6546346

Pulled By: hermanventer

fbshipit-source-id: 7c24e1ce4ebf121a6d50176e7dc124d83f7cdad4

src/intrinsics/prepack/utils.js

@@ -24,6 +24,7 @@ import { ValuesDomain } from "../../domains/index.js";
 import { describeLocation } from "../ecma262/Error.js";
 import { To } from "../../singletons.js";
 import AbstractObjectValue from "../../values/AbstractObjectValue";
+import { CompilerDiagnostic, FatalError } from "../../errors.js";
 
 const throwTemplateSrc = "(function(){throw new global.Error('abstract value defined at ' + A);})()";
 const throwTemplate = buildExpressionTemplate(throwTemplateSrc);
@@ -69,24 +70,33 @@ export function createAbstract(
   let { type, template } = parseTypeNameOrTemplate(realm, typeNameOrTemplate);
 
   let result;
+  let locString,
+    loc = null;
+  for (let executionContext of realm.contextStack.slice().reverse()) {
+    let caller = executionContext.caller;
+    loc = executionContext.loc;
+    locString = describeLocation(
+      realm,
+      caller ? caller.function : undefined,
+      caller ? caller.lexicalEnvironment : undefined,
+      loc
+    );
+    if (locString !== undefined) break;
+  }
   let nameString = name ? To.ToStringPartial(realm, name) : "";
   if (nameString === "") {
-    let locString;
-    for (let executionContext of realm.contextStack.slice().reverse()) {
-      let caller = executionContext.caller;
-      locString = describeLocation(
-        realm,
-        caller ? caller.function : undefined,
-        caller ? caller.lexicalEnvironment : undefined,
-        executionContext.loc
-      );
-      if (locString !== undefined) break;
-    }
     let locVal = new StringValue(realm, locString || "(unknown location)");
     let kind = "__abstract_" + realm.objectCount++; // need not be an object, but must be unique
     result = AbstractValue.createFromTemplate(realm, throwTemplate, type, [locVal], kind);
   } else {
-    let kind = "__abstract_" + nameString; // assume name is unique TODO #1155: check this
+    let kind = "__abstract_" + nameString;
+    if (!realm.isNameStringUnique(nameString)) {
+      let error = new CompilerDiagnostic("An abstract value with the same name exists", loc, "PP0019", "FatalError");
+      realm.handleError(error);
+      throw new FatalError();
+    } else {
+      realm.saveNameString(nameString);
+    }
     result = AbstractValue.createFromTemplate(realm, buildExpressionTemplate(nameString), type, [], kind);
     result.intrinsicName = nameString;
   }

src/realm.js

@@ -181,6 +181,7 @@ export class Realm {
     this.errorHandler = opts.errorHandler;
 
     this.globalSymbolRegistry = [];
+    this._abstractValuesDefined = new Set(); // A set of nameStrings to ensure abstract values have unique names
   }
 
   start: number;
@@ -264,6 +265,7 @@ export class Realm {
   debuggerInstance: DebugServerType | void;
 
   nextGeneratorId: number = 0;
+  _abstractValuesDefined: Set<string>;
 
   // to force flow to type the annotations
   isCompatibleWith(compatibility: Compatibility): boolean {
@@ -952,4 +954,12 @@ export class Realm {
     }
     return errorHandler(diagnostic);
   }
+
+  saveNameString(nameString: string): void {
+    this._abstractValuesDefined.add(nameString);
+  }
+
+  isNameStringUnique(nameString: string): boolean {
+    return !this._abstractValuesDefined.has(nameString);
+  }
 }

test/error-handler/abstract-value-check-dup-name-string.js

@@ -0,0 +1,4 @@
+// expected errors: [{"location": {"start":{"line":4,"column":0},"end":{"line":4,"column":27},"source":"test/error-handler/abstract-value-check-dup-name-string.js"},"severity":"FatalError","errorCode":"PP0019","message":"An abstract value with the same name exists"}]
+
+__abstract('number', 'foo');
+__abstract('number', 'foo');

test/serializer/abstract/GeneratorScoping4.js

@@ -1,6 +1,6 @@
 (function() {
-    let x = global.__abstract ? __abstract("boolean", "(true)") : true;
-    let y = global.__abstract ? __abstract("boolean", "(true)") : true;
+    let x = global.__abstract ? __abstract("boolean", "/* x = */(true)") : true;
+    let y = global.__abstract ? __abstract("boolean", "/* y = */(true)") : true;
     let obj = { p: 42 };
     if (y) {
         if (x) {

test/serializer/abstract/ObjectAssign.js

@@ -2,16 +2,16 @@ let dims = global.__abstract ? __abstract({
   window: undefined,
   screen: undefined,
   windowPhysicalPixels: __abstract({
-    width: __abstract("number", "1"),
-    height: __abstract("number", "1"),
-    scale: __abstract("number", "2"),
-    fontScale: __abstract("number", "4"),
+    width: __abstract("number", "/* windowPhysicalPixels.width = */ 1"),
+    height: __abstract("number", "/* windowPhysicalPixels.height = */ 1"),
+    scale: __abstract("number", "/* windowPhysicalPixels.scale = */ 2"),
+    fontScale: __abstract("number", "/* windowPhysicalPixels.fontScale = */4"),
   }),
   screenPhysicalPixels: __abstract({
-    width: __abstract("number", "1"),
-    height: __abstract("number", "1"),
-    scale: __abstract("number", "2"),
-    fontScale: __abstract("number", "4"),
+    width: __abstract("number", "/* screenPhysicalPixels.width = */ 1"),
+    height: __abstract("number", "/* screenPhysicalPixels.height = */1"),
+    scale: __abstract("number", "/* screenPhysicalPixels.scale = */ 2"),
+    fontScale: __abstract("number", "/*screenPhysicalPixels.fontScale = */4"),
   }),
 }, `({
   window: undefined,

test/serializer/abstract/PutValue12.js

@@ -1,6 +1,6 @@
-var n = global.__abstract ? __abstract("string", '("x")') : "x";
-var m = global.__abstract ? __abstract("string", '("x")') : "x";
-var c = global.__abstract ? __abstract("boolean", "true") : true;
+var n = global.__abstract ? __abstract("string", '/* n = */ ("x")') : "x";
+var m = global.__abstract ? __abstract("string", '/* m = */ ("x")') : "x";
+var c = global.__abstract ? __abstract("boolean", "/* c = */ true") : true;
 
 a = {x: 123, y: 444};
 if (global.__makeSimple) global.__makeSimple(a);

test/serializer/abstract/Return7.js

@@ -1,10 +1,13 @@
 let c = 0;
 let overflow = false;
-function check() {
-  return global.__abstract ? __abstract('boolean', 'true') : true;
+function check1() {
+  return global.__abstract ? __abstract('boolean', '/* check1 */ true') : true;
 }
-function call() {
-  if (check()) {
+function check2() {
+  return global.__abstract ? __abstract('boolean', '/* check2 */ true') : true;
+}
+function call1() {
+  if (check1()) {
     c = c + 1;
     if (c > 2) {
       overflow = true;
@@ -13,8 +16,18 @@ function call() {
   }
   return 4;
 }
-a = call();
-b = call();
+function call2() {
+  if (check2()) {
+    c = c + 1;
+    if (c > 2) {
+      overflow = true;
+      return 3;
+    }
+  }
+  return 4;
+}
+a = call1();
+b = call2();
 inspect = function() {
   return overflow;
 };