wip

Author: hvitved

rust/ql/lib/codeql/rust/dataflow/internal/DataFlowImpl.qll

@@ -577,11 +577,7 @@ module RustDataFlow implements InputSig<Location> {
 
   pragma[nomagic]
   private predicate implicitBorrow(Node node1, Node node2, ReferenceContent c) {
-    (
-      node1 = node2.(ImplicitDerefNode).getBorrowInputNode()
-      or
-      node1 = node2.(ImplicitBorrowNode).getBorrowInputNode()
-    ) and
+    node1 = node2.(ImplicitDerefBorrowNode).getBorrowInputNode() and
     exists(c)
   }
 
@@ -596,8 +592,6 @@ module RustDataFlow implements InputSig<Location> {
       not TypeInference::implicitDerefChainBorrow(container, _, _) and
       result.asExpr() = container
       or
-      result.(ImplicitBorrowNode).getNode() = container
-      or
       result.(ImplicitDerefNode).isLast(container)
     )
   }

rust/ql/lib/codeql/rust/dataflow/internal/Node.qll

@@ -267,17 +267,36 @@ class ImplicitDerefNodeState extends TImplicitDerefNodeState {
   }
 }
 
+/**
+ * A node used to represent implicit dereferencing/borrowing.
+ */
+abstract class ImplicitDerefBorrowNode extends Node {
+  /**
+   * Gets the node that should the predecessor in a reference store-step into this
+   * node, if any.
+   */
+  abstract Node getBorrowInputNode();
+
+  abstract AstNode getUnderlyingAstNode();
+
+  override CfgScope getCfgScope() { result = this.getUnderlyingAstNode().getEnclosingCfgScope() }
+
+  override Location getLocation() { result = this.getUnderlyingAstNode().getLocation() }
+}
+
 /**
  * A node used to represent implicit dereferencing.
  */
-class ImplicitDerefNode extends Node, TImplicitDerefNode {
+class ImplicitDerefNode extends ImplicitDerefBorrowNode, TImplicitDerefNode {
   AstNode n;
   DerefChain derefChain;
   ImplicitDerefNodeState state;
   int i;
 
   ImplicitDerefNode() { this = TImplicitDerefNode(n, derefChain, state, i, false) }
 
+  override AstNode getUnderlyingAstNode() { result = n }
+
   private predicate isNoOp() { derefChain.isNoOp(i) }
 
   private Node getInputNode() {
@@ -297,11 +316,7 @@ class ImplicitDerefNode extends Node, TImplicitDerefNode {
     result = this.getInputNode()
   }
 
-  /**
-   * Gets the node that should the predecessor in a reference store-step into this
-   * node, if any.
-   */
-  Node getBorrowInputNode() {
+  override Node getBorrowInputNode() {
     not this.isNoOp() and
     state = TImplicitDerefNodeBorrowState() and
     result = this.getInputNode()
@@ -322,10 +337,6 @@ class ImplicitDerefNode extends Node, TImplicitDerefNode {
     i = derefChain.length() - 1
   }
 
-  override CfgScope getCfgScope() { result = n.getEnclosingCfgScope() }
-
-  override Location getLocation() { result = n.getLocation() }
-
   override string toString() { result = n + " [implicit deref " + i + " in state " + state + "]" }
 }
 
@@ -366,19 +377,15 @@ private class ImplicitDerefOutNode extends ImplicitDerefNode, OutNode {
 /**
  * A node that represents the value of an expression _after_ implicit borrowing.
  */
-class ImplicitBorrowNode extends Node, TImplicitBorrowNode {
+class ImplicitBorrowNode extends ImplicitDerefBorrowNode, TImplicitBorrowNode {
   AstNode n;
   DerefChain derefChain;
 
   ImplicitBorrowNode() { this = TImplicitBorrowNode(n, derefChain, false) }
 
-  AstNode getNode() { result = n }
+  override AstNode getUnderlyingAstNode() { result = n }
 
-  /**
-   * Gets the node that should the predecessor in a reference store-step into this
-   * node.
-   */
-  Node getBorrowInputNode() {
+  override Node getBorrowInputNode() {
     result =
       TImplicitDerefNode(n, derefChain, TImplicitDerefNodeAfterDerefState(),
         derefChain.length() - 1, false)
@@ -387,10 +394,6 @@ class ImplicitBorrowNode extends Node, TImplicitBorrowNode {
     result.(AstNodeNode).getAstNode() = n
   }
 
-  override CfgScope getCfgScope() { result = n.getEnclosingCfgScope() }
-
-  override Location getLocation() { result = n.getLocation() }
-
   override string toString() { result = n + " [implicit borrow]" }
 }