Revert "Swift: Hide OpenExistentialExpr from the AST instead."

This reverts commit 9ad1749957.

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

@@ -1729,10 +1729,22 @@ module Exprs {
     }
   }
 
+  private class OpenExistentialTree extends AstStandardPostOrderTree {
+    override OpenExistentialExpr ast;
+
+    override ControlFlowElement getChildElement(int i) {
+      i = 0 and
+      result.asAstNode() = ast.getExistential().getFullyConverted()
+      or
+      i = 1 and
+      result.asAstNode() = ast.getSubExpr().getFullyConverted()
+    }
+  }
+
   module Conversions {
     class ConversionOrIdentity =
       Synth::TIdentityExpr or Synth::TExplicitCastExpr or Synth::TImplicitConversionExpr or
-          Synth::TInOutExpr or Synth::TOpenExistentialExpr;
+          Synth::TInOutExpr;
 
     abstract class ConversionOrIdentityTree extends AstStandardPostOrderTree {
       ConversionOrIdentityTree() { ast instanceof ConversionOrIdentity }
@@ -1769,12 +1781,6 @@ module Exprs {
 
       override predicate convertsFrom(Expr e) { ast.convertsFrom(e) }
     }
-
-    private class OpenExistentialTree extends ConversionOrIdentityTree {
-      override OpenExistentialExpr ast;
-
-      override predicate convertsFrom(Expr e) { ast.convertsFrom(e) }
-    }
   }
 }
 

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

@@ -247,6 +247,9 @@ private module Cached {
       nodeFrom.asExpr() = ie.getBranch(_)
     )
     or
+    // flow through OpenExistentialExpr (compiler generated expression wrapper)
+    nodeFrom.asExpr() = nodeTo.asExpr().(OpenExistentialExpr).getSubExpr()
+    or
     // flow from Expr to Pattern
     exists(Expr e, Pattern p |
       nodeFrom.asExpr() = e and

swift/ql/lib/codeql/swift/elements/expr/OpenExistentialExpr.qll

@@ -1,5 +1,4 @@
+// generated by codegen/codegen.py, remove this comment if you wish to edit this file
 private import codeql.swift.generated.expr.OpenExistentialExpr
 
-class OpenExistentialExpr extends Generated::OpenExistentialExpr {
-  override predicate convertsFrom(Expr e) { e = this.getImmediateSubExpr() }
-}
+class OpenExistentialExpr extends Generated::OpenExistentialExpr { }

swift/ql/test/library-tests/ast/PrintAst.expected

@@ -7208,12 +7208,13 @@ statements.swift:
 #  110|   getBody(): [BraceStmt] { ... }
 #  111|     getElement(0): [CallExpr] call to sink(arg:)
 #  111|       getFunction(): [DeclRefExpr] sink(arg:)
-#  111|       getArgument(0): [Argument] arg: call to source()
-#  111|         getExpr(): [CallExpr] call to source()
-#  111|           getFunction(): [MethodLookupExpr] .source()
-#  111|             getBase(): [OpaqueValueExpr] OpaqueValueExpr
-#  111|             getMethodRef(): [DeclRefExpr] source()
-#  111|         getExpr().getFullyConverted(): [OpenExistentialExpr] OpenExistentialExpr
+#  111|       getArgument(0): [Argument] arg: OpenExistentialExpr
+#  111|         getExpr(): [OpenExistentialExpr] OpenExistentialExpr
+#  111|           getSubExpr(): [CallExpr] call to source()
+#  111|             getFunction(): [MethodLookupExpr] .source()
+#  111|               getBase(): [OpaqueValueExpr] OpaqueValueExpr
+#  111|               getMethodRef(): [DeclRefExpr] source()
+#  111|           getExistential(): [DeclRefExpr] x
 #  112|     getElement(1): [CallExpr] call to sink(arg:)
 #  112|       getFunction(): [DeclRefExpr] sink(arg:)
 #  112|       getArgument(0): [Argument] arg: call to source()
@@ -7223,12 +7224,14 @@ statements.swift:
 #  112|             getMethodRef(): [DeclRefExpr] source()
 #  113|     getElement(2): [CallExpr] call to sink(arg:)
 #  113|       getFunction(): [DeclRefExpr] sink(arg:)
-#  113|       getArgument(0): [Argument] arg: call to source()
-#  113|         getExpr(): [CallExpr] call to source()
-#  113|           getFunction(): [MethodLookupExpr] .source()
-#  113|             getBase(): [OpaqueValueExpr] OpaqueValueExpr
-#  113|             getMethodRef(): [DeclRefExpr] source()
-#  113|         getExpr().getFullyConverted(): [OpenExistentialExpr] OpenExistentialExpr
+#  113|       getArgument(0): [Argument] arg: OpenExistentialExpr
+#  113|         getExpr(): [OpenExistentialExpr] OpenExistentialExpr
+#  113|           getSubExpr(): [CallExpr] call to source()
+#  113|             getFunction(): [MethodLookupExpr] .source()
+#  113|               getBase(): [OpaqueValueExpr] OpaqueValueExpr
+#  113|               getMethodRef(): [DeclRefExpr] source()
+#  113|           getExistential(): [CallExpr] call to getMyProtocol()
+#  113|             getFunction(): [DeclRefExpr] getMyProtocol()
 #  114|     getElement(3): [CallExpr] call to sink(arg:)
 #  114|       getFunction(): [DeclRefExpr] sink(arg:)
 #  114|       getArgument(0): [Argument] arg: call to source()
@@ -7237,6 +7240,3 @@ statements.swift:
 #  114|             getBase(): [CallExpr] call to getMyProtocolImpl()
 #  114|               getFunction(): [DeclRefExpr] getMyProtocolImpl()
 #  114|             getMethodRef(): [DeclRefExpr] source()
-#  111| [DeclRefExpr] x
-#  113| [CallExpr] call to getMyProtocol()
-#  113|   getFunction(): [DeclRefExpr] getMyProtocol()

swift/ql/test/library-tests/controlflow/graph/Cfg.expected

@@ -6319,7 +6319,7 @@ cfg.swift:
 #-----|  -> sink(arg:)
 
 #  554| sink(arg:)
-#-----|  -> .source()
+#-----|  -> x
 
 #  554| call to sink(arg:)
 #-----|  -> sink(arg:)
@@ -6327,6 +6327,9 @@ cfg.swift:
 #  554| OpaqueValueExpr
 #-----|  -> call to source()
 
+#  554| x
+#-----|  -> .source()
+
 #  554| .source()
 #-----|  -> OpaqueValueExpr
 
@@ -6352,14 +6355,20 @@ cfg.swift:
 #-----|  -> call to sink(arg:)
 
 #  556| sink(arg:)
-#-----|  -> .source()
+#-----|  -> getMyProtocol()
 
 #  556| call to sink(arg:)
 #-----|  -> sink(arg:)
 
+#  556| getMyProtocol()
+#-----|  -> call to getMyProtocol()
+
 #  556| OpaqueValueExpr
 #-----|  -> call to source()
 
+#  556| call to getMyProtocol()
+#-----|  -> .source()
+
 #  556| .source()
 #-----|  -> OpaqueValueExpr
 

swift/ql/test/library-tests/dataflow/dataflow/DataFlow.expected

@@ -558,6 +558,8 @@ edges
 | test.swift:873:21:873:31 | [...] [Collection element] | test.swift:856:29:856:40 | args [Collection element] |
 | test.swift:873:21:873:31 | [...] [Collection element] | test.swift:873:21:873:31 | [...] [Collection element] |
 | test.swift:873:24:873:31 | call to source() | test.swift:873:21:873:31 | [...] [Collection element] |
+| test.swift:888:12:888:21 | call to source() | test.swift:888:12:888:21 | OpenExistentialExpr |
+| test.swift:890:12:890:35 | call to source() | test.swift:890:12:890:35 | OpenExistentialExpr |
 nodes
 | file://:0:0:0:0 | .a [x] | semmle.label | .a [x] |
 | file://:0:0:0:0 | .s [x] | semmle.label | .s [x] |
@@ -1159,8 +1161,10 @@ nodes
 | test.swift:873:21:873:31 | [...] [Collection element] | semmle.label | [...] [Collection element] |
 | test.swift:873:21:873:31 | [...] [Collection element] | semmle.label | [...] [Collection element] |
 | test.swift:873:24:873:31 | call to source() | semmle.label | call to source() |
+| test.swift:888:12:888:21 | OpenExistentialExpr | semmle.label | OpenExistentialExpr |
 | test.swift:888:12:888:21 | call to source() | semmle.label | call to source() |
 | test.swift:889:12:889:21 | call to source() | semmle.label | call to source() |
+| test.swift:890:12:890:35 | OpenExistentialExpr | semmle.label | OpenExistentialExpr |
 | test.swift:890:12:890:35 | call to source() | semmle.label | call to source() |
 | test.swift:891:12:891:39 | call to source() | semmle.label | call to source() |
 subpaths
@@ -1352,7 +1356,7 @@ subpaths
 | test.swift:859:15:859:21 | ...[...] | test.swift:873:24:873:31 | call to source() | test.swift:859:15:859:21 | ...[...] | result |
 | test.swift:860:15:860:21 | ...[...] | test.swift:873:24:873:31 | call to source() | test.swift:860:15:860:21 | ...[...] | result |
 | test.swift:867:15:867:38 | \\...[...] | test.swift:873:24:873:31 | call to source() | test.swift:867:15:867:38 | \\...[...] | result |
-| test.swift:888:12:888:21 | call to source() | test.swift:888:12:888:21 | call to source() | test.swift:888:12:888:21 | call to source() | result |
+| test.swift:888:12:888:21 | OpenExistentialExpr | test.swift:888:12:888:21 | call to source() | test.swift:888:12:888:21 | OpenExistentialExpr | result |
 | test.swift:889:12:889:21 | call to source() | test.swift:889:12:889:21 | call to source() | test.swift:889:12:889:21 | call to source() | result |
-| test.swift:890:12:890:35 | call to source() | test.swift:890:12:890:35 | call to source() | test.swift:890:12:890:35 | call to source() | result |
+| test.swift:890:12:890:35 | OpenExistentialExpr | test.swift:890:12:890:35 | call to source() | test.swift:890:12:890:35 | OpenExistentialExpr | result |
 | test.swift:891:12:891:39 | call to source() | test.swift:891:12:891:39 | call to source() | test.swift:891:12:891:39 | call to source() | result |

swift/ql/test/library-tests/dataflow/dataflow/LocalFlow.expected

@@ -1093,5 +1093,9 @@
 | test.swift:880:7:880:7 | self | test.swift:880:7:880:7 | SSA def(self) |
 | test.swift:881:7:881:7 | SSA def(self) | test.swift:881:2:881:34 | self[return] |
 | test.swift:881:7:881:7 | self | test.swift:881:7:881:7 | SSA def(self) |
+| test.swift:887:30:887:33 | SSA def(x) | test.swift:888:12:888:12 | x |
+| test.swift:887:30:887:33 | x | test.swift:887:30:887:33 | SSA def(x) |
 | test.swift:887:45:887:48 | SSA def(y) | test.swift:889:12:889:12 | y |
 | test.swift:887:45:887:48 | y | test.swift:887:45:887:48 | SSA def(y) |
+| test.swift:888:12:888:21 | call to source() | test.swift:888:12:888:21 | OpenExistentialExpr |
+| test.swift:890:12:890:35 | call to source() | test.swift:890:12:890:35 | OpenExistentialExpr |

swift/ql/test/library-tests/dataflow/flowsources/FlowSourcesInline.expected

@@ -1,2 +1,2 @@
-testFailures
 failures
+testFailures