Adapt instanceof CFG and DFG to general patterns

java/ql/lib/semmle/code/java/ControlFlowGraph.qll

@@ -527,8 +527,7 @@ private module ControlFlowGraphImpl {
       or
       this instanceof NotInstanceOfExpr
       or
-      this instanceof LocalVariableDeclExpr and
-      not this = any(InstanceOfExpr ioe).getLocalVariableDeclExpr()
+      this instanceof LocalVariableDeclExpr
       or
       this instanceof StringTemplateExpr
       or
@@ -832,7 +831,7 @@ private module ControlFlowGraphImpl {
     exists(InstanceOfExpr ioe | ioe.isPattern() and ioe = n |
       last = n and completion = basicBooleanCompletion(false)
       or
-      last = ioe.getLocalVariableDeclExpr() and completion = basicBooleanCompletion(true)
+      last(ioe.getPattern(), last, NormalCompletion()) and completion = basicBooleanCompletion(true)
     )
     or
     // The last node of a node executed in post-order is the node itself.
@@ -1128,7 +1127,7 @@ private module ControlFlowGraphImpl {
       last(ioe.getExpr(), n, completion) and completion = NormalCompletion() and result = ioe
       or
       n = ioe and
-      result = ioe.getLocalVariableDeclExpr() and
+      result = first(ioe.getPattern()) and
       completion = basicBooleanCompletion(true)
     )
     or

java/ql/lib/semmle/code/java/Expr.qll

@@ -1559,20 +1559,26 @@ class SwitchExpr extends Expr, StmtParent, @switchexpr {
 class InstanceOfExpr extends Expr, @instanceofexpr {
   /** Gets the expression on the left-hand side of the `instanceof` operator. */
   Expr getExpr() {
-    if this.isPattern()
-    then result = this.getLocalVariableDeclExpr().getInit()
-    else result.isNthChildOf(this, 0)
+    result.isNthChildOf(this, 0)
   }
 
+  /**
+   * Gets the pattern of an `x instanceof T pattern` expression, if any.
+   */
+  Pattern getPattern() { result.isNthChildOf(this, 2) }
+
   /**
    * Holds if this `instanceof` expression uses pattern matching.
    */
-  predicate isPattern() { exists(this.getLocalVariableDeclExpr()) }
+  predicate isPattern() { exists(this.getPattern()) }
 
   /**
-   * Gets the local variable declaration of this `instanceof` expression if pattern matching is used.
+   * Gets the local variable declaration of this `instanceof` expression if simple pattern matching is used.
+   *
+   * Note that this won't get anything when record pattern matching is used-- for more general patterns,
+   * use `getPattern`.
    */
-  LocalVariableDeclExpr getLocalVariableDeclExpr() { result.isNthChildOf(this, 0) }
+  LocalVariableDeclExpr getLocalVariableDeclExpr() { result = this.getPattern().asBindingPattern() }
 
   /** Gets the access to the type on the right-hand side of the `instanceof` operator. */
   Expr getTypeName() { result.isNthChildOf(this, 1) }

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowUtil.qll

@@ -200,7 +200,7 @@ predicate simpleAstFlowStep(Expr e1, Expr e2) {
   )
   or
   exists(InstanceOfExpr ioe |
-    e1 = ioe.getExpr() and e2 = ioe.getLocalVariableDeclExpr()
+    e1 = ioe.getExpr() and e2 = ioe.getPattern()
   )
 }