Python: Don't report uninitialized locals in unreachable code.

markshannon · markshannon · commit 7bbe39ef01d4 · 2019-06-25T15:52:48.000+01:00
diff --git a/python/ql/src/Variables/UninitializedLocal.ql b/python/ql/src/Variables/UninitializedLocal.ql
@@ -12,7 +12,7 @@
 
 import python
 import Undefined
-
+import semmle.python.pointsto.PointsTo
 
 predicate uninitialized_local(NameNode use) {
     exists(FastLocalVariable local |
@@ -21,7 +21,7 @@ predicate uninitialized_local(NameNode use) {
     )
     and
     (
-        any(Uninitialized uninit).taints(use)
+        any(Uninitialized uninit).taints(use) and PointsToInternal::reachableBlock(use.getBasicBlock(), _)
         or
         not exists(EssaVariable var | var.getASourceUse() = use)
     )

Original file line number	Diff line number	Diff line change
`@@ -12,7 +12,7 @@`
`12`	`12`
`13`	`13`	`import python`
`14`	`14`	`import Undefined`
`15`		`-`
	`15`	`+import semmle.python.pointsto.PointsTo`
`16`	`16`
`17`	`17`	`predicate uninitialized_local(NameNode use) {`
`18`	`18`	`exists(FastLocalVariable local \|`
`@@ -21,7 +21,7 @@ predicate uninitialized_local(NameNode use) {`
`21`	`21`	`)`
`22`	`22`	`and`
`23`	`23`	`(`
`24`		`- any(Uninitialized uninit).taints(use)`
	`24`	`+ any(Uninitialized uninit).taints(use) and PointsToInternal::reachableBlock(use.getBasicBlock(), _)`
`25`	`25`	`or`
`26`	`26`	`not exists(EssaVariable var \| var.getASourceUse() = use)`
`27`	`27`	`)`