Rust: Address PR comments

Author: paldepind

rust/ql/lib/codeql/rust/dataflow/Ssa.qll

@@ -337,4 +337,37 @@ module Ssa {
 
     override Location getLocation() { result = this.getBasicBlock().getLocation() }
   }
+
+  /**
+   * An SSA definition inserted at a call that may update the value of a captured
+   * variable. For example, in
+   *
+   * ```rust
+   * fn capture_mut() {
+   *   let mut y = 0;
+   *   (0..5).for_each(|x| {
+   *     y += x
+   *   });
+   *   y
+   * }
+   * ```
+   *
+   * a definition for `y` is inserted at the call to `for_each`.
+   */
+  private class CapturedCallDefinition extends Definition, SsaImpl::UncertainWriteDefinition {
+    CapturedCallDefinition() {
+      exists(Variable v, BasicBlock bb, int i |
+        this.definesAt(v, bb, i) and
+        SsaImpl::capturedCallWrite(_, bb, i, v)
+      )
+    }
+
+    /**
+     * Gets the immediately preceding definition. Since this update is uncertain,
+     * the value from the preceding definition might still be valid.
+     */
+    final Definition getPriorDefinition() { result = SsaImpl::uncertainWriteDefinitionInput(this) }
+
+    override string toString() { result = "<captured exit> " + this.getSourceVariable() }
+  }
 }

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

@@ -289,7 +289,7 @@ module Node {
 
     override Location getLocation() { result = cfgScope.getLocation() }
 
-    override string toString() { result = "lambda self in " + cfgScope }
+    override string toString() { result = "closure self in " + cfgScope }
   }
 
   abstract class ArgumentNode extends Node {

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

@@ -467,39 +467,6 @@ class PhiReadNode extends DefinitionExt, Impl::PhiReadNode {
   override Location getLocation() { result = Impl::PhiReadNode.super.getLocation() }
 }
 
-/**
- * An SSA definition inserted at a call that may update the value of a captured
- * variable. For example, in
- *
- * ```rust
- * fn capture_mut() {
- *   let mut y = 0;
- *   (0..5).for_each(|x| {
- *     y += x
- *   });
- *   y
- * }
- * ```
- *
- * a definition for `y` is inserted at the call to `for_each`.
- */
-class CapturedCallDefinition extends Definition, Impl::UncertainWriteDefinition {
-  CapturedCallDefinition() {
-    exists(Variable v, BasicBlock bb, int i |
-      this.definesAt(v, bb, i) and
-      capturedCallWrite(_, bb, i, v)
-    )
-  }
-
-  /**
-   * Gets the immediately preceding definition. Since this update is uncertain,
-   * the value from the preceding definition might still be valid.
-   */
-  final Definition getPriorDefinition() { result = uncertainWriteDefinitionInput(this) }
-
-  override string toString() { result = "<captured exit> " + this.getSourceVariable() }
-}
-
 private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInputSig {
   class Expr extends CfgNodes::AstCfgNode {
     predicate hasCfgNode(SsaInput::BasicBlock bb, int i) { this = bb.getNode(i) }