Fix WhenExpr flow

atorralba · igfoo · commit 9735423c79df · 2022-05-10T19:51:22.000+01:00
diff --git a/java/ql/lib/semmle/code/java/ControlFlowGraph.qll b/java/ql/lib/semmle/code/java/ControlFlowGraph.qll
@@ -1248,7 +1248,7 @@ private module ControlFlowGraphImpl {
     )
     or
     // When expressions:
-    exists(WhenExpr whenexpr | n = whenexpr |
+    exists(WhenExpr whenexpr |
       n = whenexpr and
       result = first(whenexpr.getBranch(0)) and
       completion = NormalCompletion()
diff --git a/java/ql/lib/semmle/code/java/dataflow/internal/DataFlowUtil.qll b/java/ql/lib/semmle/code/java/dataflow/internal/DataFlowUtil.qll
@@ -156,6 +156,8 @@ predicate simpleLocalFlowStep(Node node1, Node node2) {
   or
   node2.asExpr() = any(NotNullExpr nne | node1.asExpr() = nne.getExpr())
   or
+  node2.asExpr().(WhenExpr).getBranch(_).getAResult() = node1.asExpr()
+  or
   exists(MethodAccess ma, ValuePreservingMethod m, int argNo |
     ma.getCallee().getSourceDeclaration() = m and m.returnsValue(argNo)
   |

Original file line number	Diff line number	Diff line change
`@@ -1248,7 +1248,7 @@ private module ControlFlowGraphImpl {`
`1248`	`1248`	`)`
`1249`	`1249`	`or`
`1250`	`1250`	`// When expressions:`
`1251`		`- exists(WhenExpr whenexpr \| n = whenexpr \|`
	`1251`	`+ exists(WhenExpr whenexpr \|`
`1252`	`1252`	`n = whenexpr and`
`1253`	`1253`	`result = first(whenexpr.getBranch(0)) and`
`1254`	`1254`	`completion = NormalCompletion()`
Original file line number	Diff line number	Diff line change
`@@ -156,6 +156,8 @@ predicate simpleLocalFlowStep(Node node1, Node node2) {`
`156`	`156`	`or`
`157`	`157`	`node2.asExpr() = any(NotNullExpr nne \| node1.asExpr() = nne.getExpr())`
`158`	`158`	`or`
	`159`	`+ node2.asExpr().(WhenExpr).getBranch(_).getAResult() = node1.asExpr()`
	`160`	`+ or`
`159`	`161`	`exists(MethodAccess ma, ValuePreservingMethod m, int argNo \|`
`160`	`162`	`ma.getCallee().getSourceDeclaration() = m and m.returnsValue(argNo)`
`161`	`163`	`\|`