Merge pull request #21552 from MathiasVP/more-public-dataflow-apis

C++: Expose indirect instructions and indirect parameters in dataflow

Author: MathiasVP

cpp/ql/lib/change-notes/2026-03-20-add-indirect-uninitialized-node.md

@@ -1,4 +1,4 @@
 ---
 category: feature
 ---
-* Added a new data flow node, `IndirectUninitializedNode`, that represents uninitialized local variables behind a number of indirections.
+* Added a class `IndirectUninitializedNode` to represent the indirection of an uninitialized local variable as a dataflow node.

cpp/ql/lib/change-notes/2026-03-23-indirect-parameter-nodes-and-indirect-instructions.md

@@ -0,0 +1,5 @@
+---
+category: feature
+---
+* Added a class `DataFlow::IndirectParameterNode` to represent the indirection of a parameter as a dataflow node.
+* Added a predicate `Node::asIndirectInstruction` which returns the `Instruction` that defines the indirect dataflow node, if any.

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowNodes.qll

@@ -321,6 +321,12 @@ module Public {
      */
     Operand asIndirectOperand(int index) { hasOperandAndIndex(this, result, index) }
 
+    /**
+     * Gets the instruction that is indirectly tracked by this node behind
+     * `index` number of indirections.
+     */
+    Instruction asIndirectInstruction(int index) { hasInstructionAndIndex(this, result, index) }
+
     /**
      * Holds if this node is at index `i` in basic block `block`.
      *
@@ -830,6 +836,12 @@ module Public {
   /** An explicit positional parameter, including `this`, but not `...`. */
   final class DirectParameterNode = AbstractDirectParameterNode;
 
+  /**
+   * A node representing an indirection of a positional parameter,
+   * including `*this`, but not `*...`.
+   */
+  final class IndirectParameterNode = AbstractIndirectParameterNode;
+
   final class ExplicitParameterNode = AbstractExplicitParameterNode;
 
   /** An implicit `this` parameter. */
@@ -989,11 +1001,6 @@ module Public {
 
 private import Public
 
-/**
- * A node representing an indirection of a parameter.
- */
-final class IndirectParameterNode = AbstractIndirectParameterNode;
-
 /**
  * A class that lifts pre-SSA dataflow nodes to regular dataflow nodes.
  */