Swift: Use asNominalTypeDecl() to simplify models.

Author: geoffw0

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/Collection.qll

@@ -48,11 +48,7 @@ private class CollectionFieldsInheritTaint extends TaintInheritingContent,
 {
   CollectionFieldsInheritTaint() {
     exists(FieldDecl f | this.getField() = f |
-      (
-        f.getEnclosingDecl().(NominalTypeDecl).getName() = ["Collection", "BidirectionalCollection"] or
-        f.getEnclosingDecl().(ExtensionDecl).getExtendedTypeDecl().getName() =
-          ["Collection", "BidirectionalCollection"]
-      ) and
+      f.getEnclosingDecl().asNominalTypeDecl().getName() = ["Collection", "BidirectionalCollection"] and
       f.getName() = ["first", "last"]
     )
   }

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/FilePath.qll

@@ -60,10 +60,7 @@ private class FilePathFieldsInheritTaint extends TaintInheritingContent,
 {
   FilePathFieldsInheritTaint() {
     exists(FieldDecl f | this.getField() = f |
-      (
-        f.getEnclosingDecl().(NominalTypeDecl) instanceof FilePath or
-        f.getEnclosingDecl().(ExtensionDecl).getExtendedTypeDecl() instanceof FilePath
-      ) and
+      f.getEnclosingDecl().asNominalTypeDecl() instanceof FilePath and
       f.getName() =
         [
           "description", "debugDescription", "components", "extension", "lastComponent", "root",
@@ -82,12 +79,8 @@ private class FilePathComponentFieldsInheritTaint extends TaintInheritingContent
 {
   FilePathComponentFieldsInheritTaint() {
     exists(FieldDecl f | this.getField() = f |
-      (
-        f.getEnclosingDecl().(NominalTypeDecl).getFullName() =
-          ["FilePath.Component", "FilePath.Root"] or
-        f.getEnclosingDecl().(ExtensionDecl).getExtendedTypeDecl().getFullName() =
-          ["FilePath.Component", "FilePath.Root"]
-      ) and
+      f.getEnclosingDecl().asNominalTypeDecl().getFullName() =
+        ["FilePath.Component", "FilePath.Root"] and
       f.getName() = ["extension", "stem", "string"]
     )
   }

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/NsString.qll

@@ -133,10 +133,7 @@ private class NsStringFieldsInheritTaint extends TaintInheritingContent,
 {
   NsStringFieldsInheritTaint() {
     exists(FieldDecl f | this.getField() = f |
-      (
-        f.getEnclosingDecl().(NominalTypeDecl).getName() = "NSString" or
-        f.getEnclosingDecl().(ExtensionDecl).getExtendedTypeDecl().getName() = "NSString"
-      ) and
+      f.getEnclosingDecl().asNominalTypeDecl().getName() = "NSString" and
       f.getName() =
         [
           "utf8String", "lowercased", "localizedLowedCase", "uppercased", "localizedUppercase",

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/Sequence.qll

@@ -38,10 +38,7 @@ private class SequenceFieldsInheritTaint extends TaintInheritingContent,
 {
   SequenceFieldsInheritTaint() {
     exists(FieldDecl f | this.getField() = f |
-      (
-        f.getEnclosingDecl().(NominalTypeDecl).getName() = "Sequence" or
-        f.getEnclosingDecl().(ExtensionDecl).getExtendedTypeDecl().getName() = "Sequence"
-      ) and
+      f.getEnclosingDecl().asNominalTypeDecl().getName() = "Sequence" and
       f.getName() = "lazy"
     )
   }

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/String.qll

@@ -125,11 +125,7 @@ private class StringFieldsInheritTaint extends TaintInheritingContent,
 {
   StringFieldsInheritTaint() {
     exists(FieldDecl f | this.getField() = f |
-      (
-        f.getEnclosingDecl().(NominalTypeDecl).getName() = ["String", "StringProtocol"] or
-        f.getEnclosingDecl().(ExtensionDecl).getExtendedTypeDecl().getName() =
-          ["String", "StringProtocol"]
-      ) and
+      f.getEnclosingDecl().asNominalTypeDecl().getName() = ["String", "StringProtocol"] and
       f.getName() =
         [
           "unicodeScalars", "utf8", "utf16", "lazy", "utf8CString", "description",

swift/ql/lib/codeql/swift/security/XXEExtensions.qll

@@ -190,13 +190,8 @@ private predicate lib2xmlOptionLocalTaintStep(DataFlow::Node source, DataFlow::N
   )
   or
   exists(ApplyExpr int32Init |
-    int32Init
-        .getStaticTarget()
-        .(Initializer)
-        .getEnclosingDecl()
-        .(ExtensionDecl)
-        .getExtendedTypeDecl()
-        .getName() = "SignedInteger"
+    int32Init.getStaticTarget().(Initializer).getEnclosingDecl().asNominalTypeDecl().getName() =
+      "SignedInteger"
   |
     source.asExpr() = int32Init.getAnArgument().getExpr() and sink.asExpr() = int32Init
   )