JS: Extend RegExpTerm in ReDoS

asger-semmle · asger-semmle · commit b8711fc64282 · 2019-11-15T09:27:19.000Z
diff --git a/javascript/ql/src/Performance/ReDoS.ql b/javascript/ql/src/Performance/ReDoS.ql
@@ -83,7 +83,7 @@ import javascript
  * A branch in a disjunction that is the root node in a literal, or a literal
  * whose root node is not a disjunction.
  */
-class RegExpRoot extends @regexpterm {
+class RegExpRoot extends RegExpTerm {
   RegExpParent parent;
 
   // RegExpTerm is abstract, so do not extend it.
@@ -94,9 +94,9 @@ class RegExpRoot extends @regexpterm {
       parent = alt.getParent()
     )
     or
-    this.(RegExpTerm).isRootTerm() and
+    this.isRootTerm() and
     not this instanceof RegExpAlt and
-    parent = this.(RegExpTerm).getParent()
+    parent = this.getParent()
   }
 
   /**
@@ -114,8 +114,6 @@ class RegExpRoot extends @regexpterm {
       parent.(StringLiteral).flow() instanceof RegExpPatternSource
     )
   }
-
-  string toString() { result = this.(RegExpTerm).toString() }
 }
 
 /**

Original file line number	Diff line number	Diff line change
`@@ -83,7 +83,7 @@ import javascript`
`83`	`83`	`* A branch in a disjunction that is the root node in a literal, or a literal`
`84`	`84`	`* whose root node is not a disjunction.`
`85`	`85`	`*/`
`86`		`-class RegExpRoot extends @regexpterm {`
	`86`	`+class RegExpRoot extends RegExpTerm {`
`87`	`87`	`RegExpParent parent;`
`88`	`88`
`89`	`89`	`// RegExpTerm is abstract, so do not extend it.`
`@@ -94,9 +94,9 @@ class RegExpRoot extends @regexpterm {`
`94`	`94`	`parent = alt.getParent()`
`95`	`95`	`)`
`96`	`96`	`or`
`97`		`- this.(RegExpTerm).isRootTerm() and`
	`97`	`+ this.isRootTerm() and`
`98`	`98`	`not this instanceof RegExpAlt and`
`99`		`- parent = this.(RegExpTerm).getParent()`
	`99`	`+ parent = this.getParent()`
`100`	`100`	`}`
`101`	`101`
`102`	`102`	`/**`
`@@ -114,8 +114,6 @@ class RegExpRoot extends @regexpterm {`
`114`	`114`	`parent.(StringLiteral).flow() instanceof RegExpPatternSource`
`115`	`115`	`)`
`116`	`116`	`}`
`117`		`-`
`118`		`- string toString() { result = this.(RegExpTerm).toString() }`
`119`	`117`	`}`
`120`	`118`
`121`	`119`	`/**`