Merge pull request #967 from hvitved/csharp/ssa/block-precedes-var

calumgrant · web-flow · commit cd721f38b8e4 · 2019-02-22T14:08:26.000Z
C#: Use explict recursion in `blockPrecedesVar()`
diff --git a/csharp/ql/src/semmle/code/csharp/dataflow/SSA.qll b/csharp/ql/src/semmle/code/csharp/dataflow/SSA.qll
@@ -670,7 +670,9 @@ module Ssa {
 
     /** Holds if `v` occurs in `bb` or one of `bb`'s transitive successors. */
     private predicate blockPrecedesVar(TrackedVar v, BasicBlock bb) {
-      varOccursInBlock(v, bb.getASuccessor*())
+      varOccursInBlock(v, bb)
+      or
+      blockPrecedesVar(v, bb.getASuccessor())
     }
 
     /**

Original file line number	Diff line number	Diff line change
`@@ -670,7 +670,9 @@ module Ssa {`
`670`	`670`
`671`	`671`	/** Holds if `v` occurs in `bb` or one of `bb`'s transitive successors. */
`672`	`672`	`private predicate blockPrecedesVar(TrackedVar v, BasicBlock bb) {`
`673`		`- varOccursInBlock(v, bb.getASuccessor*())`
	`673`	`+ varOccursInBlock(v, bb)`
	`674`	`+ or`
	`675`	`+ blockPrecedesVar(v, bb.getASuccessor())`
`674`	`676`	`}`
`675`	`677`
`676`	`678`	`/**`