unified: Add Pattern.getEnclosingPattern()

Author: asgerf

unified/ql/lib/codeql/unified/internal/FacadeAst.qll

@@ -17,4 +17,13 @@ module Unified {
       )
     }
   }
+
+  class Pattern extends G::Pattern {
+    /** Gets the immediately-enclosing pattern in which this is a nested pattern. */
+    Pattern getEnclosingPattern() {
+      result = this.getParent()
+      or
+      result = this.getParent().(PatternElement).getParent()
+    }
+  }
 }

unified/ql/lib/codeql/unified/internal/Variables.qll

@@ -192,25 +192,7 @@ private module LocalNameBindingInput implements LocalNameBindingInputSig<Locatio
       pattern = stmt.getPattern()
     )
     or
-    exists(TuplePattern pat |
-      bindingContext(pat, scope) and
-      pattern = pat.getElement(_).getPattern()
-    )
-    or
-    exists(ConstructorPattern pat |
-      bindingContext(pat, scope) and
-      pattern = pat.getElement(_).getPattern()
-    )
-    or
-    exists(OrPattern pat |
-      bindingContext(pat, scope) and
-      pattern = pat.getPattern(_)
-    )
-    or
-    exists(ConditionalPattern pat |
-      bindingContext(pat, scope) and
-      pattern = pat.getPattern()
-    )
+    bindingContext(pattern.(Pattern).getEnclosingPattern(), scope)
     or
     exists(PatternGuardExpr expr |
       pattern = expr.getPattern() and
@@ -230,11 +212,8 @@ private module LocalNameBindingInput implements LocalNameBindingInputSig<Locatio
   private OrPattern getEnclosingOrPattern(Pattern p) {
     p = result.getPattern(_)
     or
-    exists(Pattern parent | result = getEnclosingOrPattern(parent) |
-      p = parent.(ConstructorPattern).getElement(_).getPattern()
-      or
-      p = parent.(TuplePattern).getElement(_).getPattern()
-    )
+    not p instanceof OrPattern and
+    result = getEnclosingOrPattern(p.getEnclosingPattern())
   }
 
   predicate declInScope(AstNode definingNode, string name, AstNode scope) {

unified/ql/test/library-tests/variables/variables.expected

@@ -1,4 +1,2 @@
 testFailures
 ambiguousVariable
-| test.swift:352:10:353:17 | y | y | test.swift | 352 |
-| test.swift:352:17:352:17 | y | y | test.swift | 352 |