Swift: distinguish Pattern.get(Immediate)EnclosingPattern

Author: d10c

swift/ql/lib/codeql/swift/controlflow/internal/Completion.qll

@@ -185,7 +185,7 @@ private predicate switchMatching(SwitchStmt switch, CaseStmt c, AstNode ast) {
   (
     c.getALabel() = ast
     or
-    ast.(Pattern).getEnclosingPattern+() = c.getALabel().getPattern()
+    ast.(Pattern).getImmediateEnclosingPattern+() = c.getALabel().getPattern()
   )
 }
 
@@ -216,7 +216,7 @@ predicate catchMatchingPattern(DoCatchStmt s, CaseStmt c, Pattern pattern) {
   exists(CaseLabelItem cli | catchMatching(s, c, cli) |
     cli.getPattern() = pattern
     or
-    pattern.getEnclosingPattern+() = cli.getPattern()
+    pattern.getImmediateEnclosingPattern+() = cli.getPattern()
   )
 }
 

swift/ql/lib/codeql/swift/dataflow/internal/DataFlowPrivate.qll

@@ -596,7 +596,7 @@ predicate readStep(Node node1, ContentSet c, Node node2) {
     exists(EnumElementPattern enumPat, NamedPattern namePat, int idx |
       enumPat.getMatchingExpr() = enumExpr and
       enumPat.getElement().getParam(idx) = enumParam and
-      namePat.getIdentityPreservingEnclosingPattern*() = enumPat.getSubPattern(idx) and
+      namePat.getImmediateIdentityPreservingEnclosingPattern*() = enumPat.getSubPattern(idx) and
       namePat.getVarDecl() = boundVar
     )
   )

swift/ql/lib/codeql/swift/elements/pattern/NamedPattern.qll

@@ -19,7 +19,7 @@ class NamedPattern extends Generated::NamedPattern {
    * This will be the case as long as the variable is subsequently used.
    */
   VarDecl getVarDecl() {
-    this.getEnclosingPattern*() = result.getParentPattern().getFullyUnresolved() and
+    this.getImmediateEnclosingPattern*() = result.getParentPattern().getFullyUnresolved() and
     result.getName() = this.getName()
   }
 

swift/ql/lib/codeql/swift/elements/pattern/Pattern.qll

@@ -70,21 +70,28 @@ class Pattern extends Generated::Pattern {
    * Holds if this occurs as a sub-pattern of the result.
    */
   Pattern getEnclosingPattern() {
+    result = this.getFullyUnresolved().(Pattern).getImmediateEnclosingPattern()
+  }
+
+  /**
+   * Holds if this occurs as an immediate sub-pattern of the result.
+   */
+  Pattern getImmediateEnclosingPattern() {
     this = result.(EnumElementPattern).getImmediateSubPattern()
     or
     this = result.(OptionalSomePattern).getImmediateSubPattern()
     or
     this = result.(TuplePattern).getImmediateElement(_)
     or
-    result = this.getIdentityPreservingEnclosingPattern()
+    result = this.getImmediateIdentityPreservingEnclosingPattern()
   }
 
   /**
-   * Holds if this occurs as a sub-pattern of the result
+   * Holds if this occurs as an immediate sub-pattern of the result
    * without any intervening destructurings of
    * complex data structures.
    */
-  Pattern getIdentityPreservingEnclosingPattern() {
+  Pattern getImmediateIdentityPreservingEnclosingPattern() {
     this = result.(BindingPattern).getImmediateSubPattern()
     or
     this = result.(IsPattern).getImmediateSubPattern()