JS: Fix perf issue in mayReceiveArgument

asgerf · asgerf · commit 4391b70b5f8e · 2020-03-12T13:45:34.000Z
diff --git a/javascript/ql/src/semmle/javascript/dataflow/internal/VariableTypeInference.qll b/javascript/ql/src/semmle/javascript/dataflow/internal/VariableTypeInference.qll
@@ -697,14 +697,14 @@ abstract private class CallWithAnalyzedParameters extends FunctionWithAnalyzedPa
   }
 
   override predicate mayReceiveArgument(Parameter p) {
-    exists(DataFlow::InvokeNode invk, int argIdx |
-      invk = getAnInvocation() and
-      p = getParameter(argIdx)
-    |
-      exists(invk.getArgument(argIdx))
-      or
-      invk.asExpr().(InvokeExpr).isSpreadArgument([0 .. argIdx])
+    exists(int argIdx |
+      p = getParameter(argIdx) and
+      getAnInvocation().getNumArgument() > argIdx
     )
+    or
+    // All parameters may receive an argument if invoked with a spread argument
+    p = getAParameter() and
+    getAnInvocation().asExpr().(InvokeExpr).isSpreadArgument(_)
   }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -697,14 +697,14 @@ abstract private class CallWithAnalyzedParameters extends FunctionWithAnalyzedPa`
`697`	`697`	`}`
`698`	`698`
`699`	`699`	`override predicate mayReceiveArgument(Parameter p) {`
`700`		`- exists(DataFlow::InvokeNode invk, int argIdx \|`
`701`		`- invk = getAnInvocation() and`
`702`		`- p = getParameter(argIdx)`
`703`		`- \|`
`704`		`- exists(invk.getArgument(argIdx))`
`705`		`- or`
`706`		`- invk.asExpr().(InvokeExpr).isSpreadArgument([0 .. argIdx])`
	`700`	`+ exists(int argIdx \|`
	`701`	`+ p = getParameter(argIdx) and`
	`702`	`+ getAnInvocation().getNumArgument() > argIdx`
`707`	`703`	`)`
	`704`	`+ or`
	`705`	`+ // All parameters may receive an argument if invoked with a spread argument`
	`706`	`+ p = getAParameter() and`
	`707`	`+ getAnInvocation().asExpr().(InvokeExpr).isSpreadArgument(_)`
`708`	`708`	`}`
`709`	`709`	`}`
`710`	`710`