From 3ca261a18e558a6d8bb88d9e7bc9e88d35b876f3 Mon Sep 17 00:00:00 2001
From: Tom Hvitved <hvitved@github.com>
Date: Tue, 1 Sep 2026 13:58:36 +0200
Subject: [PATCH] Unified: Move `extension` workaround into static name binding
 library

---
 .../ql/lib/codeql/unified/internal/AnalysisQuality.qll |  6 ------
 .../lib/codeql/unified/internal/LocalNameBinding.qll   |  3 +++
 .../lib/codeql/unified/internal/StaticNameBinding.qll  |  1 -
 .../test/library-tests/static-name-binding/test.swift  | 10 +++++++++-
 4 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/unified/ql/lib/codeql/unified/internal/AnalysisQuality.qll b/unified/ql/lib/codeql/unified/internal/AnalysisQuality.qll
index d894e02e2c7e..6f899bba4283 100644
--- a/unified/ql/lib/codeql/unified/internal/AnalysisQuality.qll
+++ b/unified/ql/lib/codeql/unified/internal/AnalysisQuality.qll
@@ -53,12 +53,6 @@ module StaticNameResolutionStats implements EntityStatsSig {
         or
         result.isModuleScopeNode(_) and
         result.(NamespaceNode).ref().isIdentifier(this)
-      ) and
-      // Do not consider a type extension to be a valid target
-      // TODO: Fix in the AST mapping: type extensions should reference their type, not declare it
-      not exists(ClassLikeDeclaration cls |
-        cls.hasModifier("extension") and
-        result.isIdentifier(cls.getName())
       )
     }
 
diff --git a/unified/ql/lib/codeql/unified/internal/LocalNameBinding.qll b/unified/ql/lib/codeql/unified/internal/LocalNameBinding.qll
index e9ffcd8a29af..5a44080464cc 100644
--- a/unified/ql/lib/codeql/unified/internal/LocalNameBinding.qll
+++ b/unified/ql/lib/codeql/unified/internal/LocalNameBinding.qll
@@ -231,6 +231,7 @@ private module LocalNameBindingInput implements LocalNameBindingInputSig<Locatio
     exists(ClassLikeDeclaration cls |
       getChild(scope, _) = cls and
       pattern = cls.getName() and
+      not cls.hasModifier("extension") and // TODO: Fix in the AST mapping: type extensions should reference their type, not declare it
       declaration = cls
     )
     or
@@ -382,6 +383,8 @@ class PotentialLocalNameAccess extends Identifier {
     this = any(NamedTypeExpr e | not exists(e.getQualifier())).getName()
     or
     this instanceof NameDeclaration
+    or
+    this = any(ClassLikeDeclaration cls | cls.hasModifier("extension")).getName() // TODO: Fix in the AST mapping: type extensions should reference their type, not declare it
   }
 
   LocalName getLocalName() { result = this.(LocalNameBindingOutput::LocalAccess).getLocal() }
diff --git a/unified/ql/lib/codeql/unified/internal/StaticNameBinding.qll b/unified/ql/lib/codeql/unified/internal/StaticNameBinding.qll
index 989ffc59357d..d0f0288704e4 100644
--- a/unified/ql/lib/codeql/unified/internal/StaticNameBinding.qll
+++ b/unified/ql/lib/codeql/unified/internal/StaticNameBinding.qll
@@ -476,7 +476,6 @@ private module FolderHeuristic {
     exists(TopLevel top, Stmt stmt, NameDeclaration nameDecl |
       top.getFile() = file and
       stmt = top.getBody().getAStmt() and
-      not stmt.(ClassLikeDeclaration).hasModifier("extension") and // TODO: target of type extensions should not be seen as a NameDeclaration
       not isPrivateToLocalScope(nameDecl) and
       nameDecl.getDeclaration() = stmt and
       name = nameDecl.getName() and
diff --git a/unified/ql/test/library-tests/static-name-binding/test.swift b/unified/ql/test/library-tests/static-name-binding/test.swift
index 64a385ef29b4..0fc9ae1c42e2 100644
--- a/unified/ql/test/library-tests/static-name-binding/test.swift
+++ b/unified/ql/test/library-tests/static-name-binding/test.swift
@@ -46,7 +46,7 @@ class F {
 typealias G = A // $ access=A
 
 // Members can be accessed through aliases, but references to the alias itself do not bypass the alias.
-class H {
+class H { // name=H1
     let x1: G = nil; // $ access=G
     let x2: G.B = nil; // $ access=G access=A.B
     let x3: G.B.C = nil; // $ access=G access=A.B access=A.B.C
@@ -62,3 +62,11 @@ func useI() {
     I.two // $ access=I access=I.two
     I.three // $ access=I access=I.three
 }
+
+protocol P { }
+
+extension H // $ access=H1
+  : P { } // $ access=P
+
+extension A.B.C // $ MISSING: access=A access=A.B access=A.B.C (`A.B.C` is currently parsed as a single identifier)
+  : P { } // $ access=P
\ No newline at end of file