Rust: Address PR comments

Author: paldepind

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

@@ -155,7 +155,7 @@ private predicate variableReadActual(BasicBlock bb, int i, Variable v) {
  */
 pragma[noinline]
 private predicate hasCapturedWrite(Variable v, Cfg::CfgScope scope) {
-  any(VariableWriteAccess write | write.getVariable() = v and scope = write.getEnclosingCallable*())
+  any(VariableWriteAccess write | write.getVariable() = v and scope = write.getEnclosingCallable+())
       .isCapture()
 }
 
@@ -262,7 +262,7 @@ private predicate readsCapturedVariable(BasicBlock bb, Variable v) {
  */
 pragma[noinline]
 private predicate hasCapturedRead(Variable v, Cfg::CfgScope scope) {
-  any(VariableReadAccess read | read.getVariable() = v and scope = read.getEnclosingCallable*())
+  any(VariableReadAccess read | read.getVariable() = v and scope = read.getEnclosingCallable+())
       .isCapture()
 }
 
@@ -290,6 +290,19 @@ private predicate capturedCallRead(CallExprBase call, BasicBlock bb, int i, Vari
   )
 }
 
+/**
+ * Holds if the call `call` at index `i` in basic block `bb` may reach a callable
+ * that writes captured variable `v`.
+ */
+predicate capturedCallWrite(CallExprBase call, BasicBlock bb, int i, Variable v) {
+  call = bb.getNode(i).getAstNode() and
+  exists(Cfg::CfgScope scope |
+    hasVariableReadWithCapturedWrite(bb, any(int j | j > i), v, scope)
+    or
+    hasVariableReadWithCapturedWrite(bb.getASuccessor+(), _, v, scope)
+  )
+}
+
 /**
  * Holds if a pseudo read of captured variable `v` should be inserted
  * at index `i` in exit block `bb`.
@@ -312,20 +325,6 @@ private module Cached {
     i = -1
   }
 
-  /**
-   * Holds if the call `call` at index `i` in basic block `bb` may reach a callable
-   * that writes captured variable `v`.
-   */
-  cached
-  predicate capturedCallWrite(CallExprBase call, BasicBlock bb, int i, Variable v) {
-    call = bb.getNode(i).getAstNode() and
-    exists(Cfg::CfgScope scope |
-      hasVariableReadWithCapturedWrite(bb, any(int j | j > i), v, scope)
-      or
-      hasVariableReadWithCapturedWrite(bb.getASuccessor+(), _, v, scope)
-    )
-  }
-
   /**
    * Holds if `v` is written at index `i` in basic block `bb`, and the corresponding
    * AST write access is `write`.