Swift: add children to UnspecifiedElement

This will allow better downgrade scripts in the future.

swift/downgrades/c0db61944f46ba5507f207ec2b1cff77ad0529a1/upgrade.properties

@@ -0,0 +1,3 @@
+description: Revert adding children to `UnspecifiedElement`
+compatibility: backwards
+unspecified_element_children.rel: delete

swift/ql/.generated.list

@@ -376,15 +376,15 @@ lib/codeql/swift/generated/KeyPathComponent.qll c79c7bc04fc1426992ab472eedc1a20a
 lib/codeql/swift/generated/Locatable.qll be20967d48a34cdba126fe298606e0adc11697831f097acba9c52a0b7ce9983e 8aa01bc376614abbc3209e25785c72f86c9b4e94bb5f471a4a0677fedaec4f61
 lib/codeql/swift/generated/Location.qll c5793987e77812059a28254dadee29bfe9b38153c0399fbb1bf6a2f5c237fdab 6e6d8802b021e36bbaad81845657769dd48a798ea33080ada05e9818a20b38f7
 lib/codeql/swift/generated/OtherAvailabilitySpec.qll 0e26a203b26ff0581b7396b0c6d1606feec5cc32477f676585cdec4911af91c5 0e26a203b26ff0581b7396b0c6d1606feec5cc32477f676585cdec4911af91c5
-lib/codeql/swift/generated/ParentChild.qll 6415d679ce1d6fa227751ce260e4c3322494151c8df7e6e66c3d4b11878c3b9a 2e3ae6706170c1fdaaab947b55b145d50175c4e8ca669c8160bf2a4ee6524c7f
+lib/codeql/swift/generated/ParentChild.qll 6e7b64896a2ad25a06130592ba27036e0e2b9bf4268a730d1bce78ebaf32607d dfe0e3c578f726cf2b7d024bf247701f12d6a79fd061a3c805d23fac85218635
 lib/codeql/swift/generated/PlatformVersionAvailabilitySpec.qll f82d9ca416fe8bd59b5531b65b1c74c9f317b3297a6101544a11339a1cffce38 7f5c6d3309e66c134107afe55bae76dfc9a72cb7cdd6d4c3706b6b34cee09fa0
 lib/codeql/swift/generated/PureSynthConstructors.qll 173c0dd59396a1de26fe870e3bc2766c46de689da2a4d8807cb62023bbce1a98 173c0dd59396a1de26fe870e3bc2766c46de689da2a4d8807cb62023bbce1a98
-lib/codeql/swift/generated/Raw.qll 233caf2d5f8d584c20e023151aefe7be454013ed3fd73239d35528b1e74af1c5 e0d8ad912aa936d0766fdd9183d35057876d08e7cbcbbd01ff6e9d3d615f1046
+lib/codeql/swift/generated/Raw.qll 349eb78e973669d9f30922399571bc31313f781c82c2993cdae4b03493440c1d 1537b15a42b35dd7e22a7e22e70dce38ed93e00e79678bbd78cfd14c1433fcbe
 lib/codeql/swift/generated/Synth.qll 551fdf7e4b53f9ee1314d1bb42c2638cf82f45bfa1f40a635dfa7b6072e4418c 9ab178464700a19951fc5285acacda4913addee81515d8e072b3d7055935a814
 lib/codeql/swift/generated/SynthConstructors.qll 2f801bd8b0db829b0253cd459ed3253c1fdfc55dce68ebc53e7fec138ef0aca4 2f801bd8b0db829b0253cd459ed3253c1fdfc55dce68ebc53e7fec138ef0aca4
 lib/codeql/swift/generated/UnknownFile.qll 0fcf9beb8de79440bcdfff4bb6ab3dd139bd273e6c32754e05e6a632651e85f6 0fcf9beb8de79440bcdfff4bb6ab3dd139bd273e6c32754e05e6a632651e85f6
 lib/codeql/swift/generated/UnknownLocation.qll e50efefa02a0ec1ff635a00951b5924602fc8cab57e5756e4a039382c69d3882 e50efefa02a0ec1ff635a00951b5924602fc8cab57e5756e4a039382c69d3882
-lib/codeql/swift/generated/UnspecifiedElement.qll ad04c197266069baf505e529e62751ab3056b4bac5db378fe1f79bbdfa29e066 a5058c7e3e0ba7d52710161e349a71f3e963d4abe07ca581ad663395fc50e972
+lib/codeql/swift/generated/UnspecifiedElement.qll bfe0dfb0a34fe8f7501710809cdfb82dc423bece9f3bcd23ebfb0e3ecb7aadf7 cdf7553ba0324a7670f6a275ff99bad96498f7363234f829533a27b6e97892f4
 lib/codeql/swift/generated/decl/AbstractStorageDecl.qll 4e827d05b3b98c043f925a3bd9c00622da3dc6e3d3406f5a18b2c3a684e3774f 47e5767a6f9a87f848cccce651d8c40af8aa3e0e727fc147cbf4d5a2a3e483d9
 lib/codeql/swift/generated/decl/AbstractTypeParamDecl.qll 1e268b00d0f2dbbd85aa70ac206c5e4a4612f06ba0091e5253483635f486ccf9 5479e13e99f68f1f347283535f8098964f7fd4a34326ff36ad5711b2de1ab0d0
 lib/codeql/swift/generated/decl/Accessor.qll c93cdf7dbb87e6c9b09b5fcf469b952041f753914a892addeb24bb46eaa51d29 1e8104da2da146d3e4d8f5f96b87872e63162e53b46f9c7038c75db51a676599

swift/ql/lib/change-notes/2023-10-18-unspecified-element-children.md

@@ -0,0 +1,5 @@
+---
+category: minorAnalysis
+---
+
+* Added children of `UnspecifiedElement`, which will be present only in certain downgraded databases.

swift/ql/lib/codeql/swift/generated/ParentChild.qll

@@ -244,15 +244,19 @@ private module Impl {
   private Element getImmediateChildOfUnspecifiedElement(
     UnspecifiedElement e, int index, string partialPredicateCall
   ) {
-    exists(int b, int bErrorElement, int n |
+    exists(int b, int bErrorElement, int n, int nChild |
       b = 0 and
       bErrorElement =
         b + 1 + max(int i | i = -1 or exists(getImmediateChildOfErrorElement(e, i, _)) | i) and
       n = bErrorElement and
+      nChild = n + 1 + max(int i | i = -1 or exists(e.getImmediateChild(i)) | i) and
       (
         none()
         or
         result = getImmediateChildOfErrorElement(e, index - b, partialPredicateCall)
+        or
+        result = e.getImmediateChild(index - n) and
+        partialPredicateCall = "Child(" + (index - n).toString() + ")"
       )
     )
   }

swift/ql/lib/codeql/swift/generated/Raw.qll

@@ -271,6 +271,13 @@ module Raw {
      * Gets the error of this unspecified element.
      */
     string getError() { unspecified_elements(this, _, result) }
+
+    /**
+     * Gets the `index`th child of this unspecified element (0-based).
+     *
+     * These will be present only in certain downgraded databases.
+     */
+    AstNode getChild(int index) { unspecified_element_children(this, index, result) }
   }
 
   /**

swift/ql/lib/codeql/swift/generated/UnspecifiedElement.qll

@@ -1,6 +1,7 @@
 // generated by codegen/codegen.py
 private import codeql.swift.generated.Synth
 private import codeql.swift.generated.Raw
+import codeql.swift.elements.AstNode
 import codeql.swift.elements.Element
 import codeql.swift.elements.ErrorElement
 
@@ -61,5 +62,40 @@ module Generated {
     string getError() {
       result = Synth::convertUnspecifiedElementToRaw(this).(Raw::UnspecifiedElement).getError()
     }
+
+    /**
+     * Gets the `index`th child of this unspecified element (0-based).
+     *
+     * This includes nodes from the "hidden" AST. It can be overridden in subclasses to change the
+     * behavior of both the `Immediate` and non-`Immediate` versions.
+     */
+    AstNode getImmediateChild(int index) {
+      result =
+        Synth::convertAstNodeFromRaw(Synth::convertUnspecifiedElementToRaw(this)
+              .(Raw::UnspecifiedElement)
+              .getChild(index))
+    }
+
+    /**
+     * Gets the `index`th child of this unspecified element (0-based).
+     *
+     * These will be present only in certain downgraded databases.
+     */
+    final AstNode getChild(int index) {
+      exists(AstNode immediate |
+        immediate = this.getImmediateChild(index) and
+        result = immediate.resolve()
+      )
+    }
+
+    /**
+     * Gets any of the children of this unspecified element.
+     */
+    final AstNode getAChild() { result = this.getChild(_) }
+
+    /**
+     * Gets the number of children of this unspecified element.
+     */
+    final int getNumberOfChildren() { result = count(int i | exists(this.getChild(i))) }
   }
 }

swift/ql/lib/swift.dbscheme

@@ -217,6 +217,13 @@ unspecified_element_indices(
   int index: int ref
 );
 
+#keyset[id, index]
+unspecified_element_children(
+  int id: @unspecified_element ref,
+  int index: int ref,
+  int child: @ast_node_or_none ref
+);
+
 other_availability_specs(
   unique int id: @other_availability_spec
 );

swift/ql/lib/upgrades/dd1bfe298d87cd82cb0d26e3349ada7244778785/upgrade.properties

@@ -0,0 +1,2 @@
+description: Add children to `UnspecifiedElement`
+compatibility: full

swift/schema.py

@@ -47,6 +47,7 @@ class UnspecifiedElement(ErrorElement):
     property: string
     index: optional[int]
     error: string
+    children: list["AstNode"] | child | desc("These will be present only in certain downgraded databases.")
 
 class Comment(Locatable):
     text: string