Add support for SwiftIfConfig and lookup if config handling.

Author: MAJKFL

include/swift/Bridging/ASTGen.h

@@ -119,6 +119,7 @@ void swift_ASTGen_freeConfiguredRegions(
 
 bool swift_ASTGen_validateUnqualifiedLookup(
     void *_Nonnull sourceFile,
+    BridgedASTContext astContext,
     BridgedSourceLoc sourceLoc,
     bool finishInSequentialScope,
     BridgedArrayRef astScopeResultRef);

lib/AST/ASTScope.cpp

@@ -167,6 +167,7 @@ void ASTScope::unqualifiedLookup(
     ASTScopeImpl::unqualifiedLookup(SF, loc, loggingASTScopeDeclConsumer);
 
     bool passed = swift_ASTGen_validateUnqualifiedLookup(SF->getExportedSourceFile(),
+                                           SF->getASTContext(),
                                            loc,
                                            loggingASTScopeDeclConsumer.finishLookupInBraceStmt(nullptr),
                                            BridgedArrayRef(loggingASTScopeDeclConsumer.recordedElements.data(), loggingASTScopeDeclConsumer.recordedElements.size())

lib/ASTGen/Sources/ASTGen/LexicalLookup.swift

@@ -20,6 +20,7 @@ private let rowCharWidth: Int = 30
 @_cdecl("swift_ASTGen_validateUnqualifiedLookup")
 public func unqualifiedLookup(
   sourceFilePtr: UnsafeRawPointer,
+  astContext: BridgedASTContext,
   lookupAt: BridgedSourceLoc,
   finishInSequentialScope: Bool,
   astScopeResultRef: BridgedArrayRef
@@ -29,6 +30,11 @@ public func unqualifiedLookup(
   let sourceFileSyntax = sourceFile.pointee.syntax
   let sourceLocationConverter = sourceFile.pointee.sourceLocationConverter
 
+  let buildConfiguration = CompilerBuildConfiguration(
+    ctx: astContext,
+    sourceBuffer: sourceFile.pointee.buffer
+  )
+  
   guard let lookupPosition = sourceFile.pointee.position(of: lookupAt),
         let lookupToken = sourceFileSyntax.token(at: lookupPosition)
   else {
@@ -37,10 +43,17 @@ public func unqualifiedLookup(
   }
 
   // Map AST result
-  let astResults = astConsumedResults(sourceFile: sourceFile, astScopeResultRef: astScopeResultRef)
+  let astResults = astConsumedResults(
+    sourceFile: sourceFile,
+    astScopeResultRef: astScopeResultRef
+  )
 
   // Map SLL result
-  let sllResults = sllConsumedResults(lookupToken: lookupToken, finishInSequentialScope: finishInSequentialScope)
+  let sllResults = sllConsumedResults(
+    lookupToken: lookupToken,
+    finishInSequentialScope: finishInSequentialScope,
+    buildConfiguration: buildConfiguration
+  )
 
   // Add header to the output
   var consoleOutput = "-----> Lookup started at: \(sourceLocationConverter.location(for: lookupPosition).lineWithColumn) (\"\(lookupToken.text)\") finishInSequentialScope: \(finishInSequentialScope)\n"
@@ -99,6 +112,8 @@ private func isInvalidFirstNameInDeclarationIntroduction(
     SwitchCaseSyntax.self,
     ClosureExprSyntax.self,
     AccessorDeclSyntax.self,
+    AccessorBlockSyntax.self,
+    ForStmtSyntax.self,
     PatternBindingSyntax.self
   ]
 
@@ -151,9 +166,10 @@ private func astConsumedResults(
 /// the results an array of `ConsumedLookupResult`. Introduces appropriate flags.
 private func sllConsumedResults(
   lookupToken: TokenSyntax,
-  finishInSequentialScope: Bool
+  finishInSequentialScope: Bool,
+  buildConfiguration: CompilerBuildConfiguration
 ) -> [ConsumedLookupResult] {
-  lookupToken.lookup(nil, with: LookupConfig(finishInSequentialScope: finishInSequentialScope))
+  lookupToken.lookup(nil, with: LookupConfig(finishInSequentialScope: finishInSequentialScope, buildConfiguration: buildConfiguration))
     .flatMap { result in
       switch result {
       case .lookInMembers(let lookInMembers):
@@ -176,9 +192,15 @@ private func sllConsumedResults(
         )]
       default:
         if let parent = result.scope.parent, result.scope.is(GenericParameterClauseSyntax.self) {
-          if (parent.is(FunctionDeclSyntax.self) ||
-            parent.is(SubscriptDeclSyntax.self) ||
-              result.scope.range.contains(lookupToken.position)) {
+          if let parentFunctionDecl = parent.as(FunctionDeclSyntax.self),
+             parentFunctionDecl.attributes.range.contains(lookupToken.position) {
+            // If lookup started fron function attributes, don't reverse
+            return result.names.map { name in
+              ConsumedLookupResult(rawName: name.identifier?.name ?? "", position: name.position, flags: [])
+            }
+          } else if parent.is(FunctionDeclSyntax.self) ||
+                    parent.is(SubscriptDeclSyntax.self) ||
+                    result.scope.range.contains(lookupToken.position) {
             // If a result from function generic parameter clause or lookup started within it, reverse introduced names.
             return result.names.reversed().map { name in
               ConsumedLookupResult(rawName: name.identifier?.name ?? "", position: name.position, flags: .placementRearranged)
@@ -188,6 +210,15 @@ private func sllConsumedResults(
             return result.names.reversed().map { name in
               ConsumedLookupResult(rawName: name.identifier?.name ?? "", position: name.position, flags: .placementRearranged)
             }
+          } else if let initializerDecl = parent.as(InitializerDeclSyntax.self),
+                    initializerDecl.range.contains(lookupToken.position) {
+            return result.names.reversed().map { name in
+              ConsumedLookupResult(rawName: name.identifier?.name ?? "", position: name.position, flags: .placementRearranged)
+            }
+          } else if parent.is(TypeAliasDeclSyntax.self) {
+            return result.names.reversed().map { name in
+              ConsumedLookupResult(rawName: name.identifier?.name ?? "", position: name.position, flags: .placementRearranged)
+            }
           }
 
           // No flags or reorderings to perform.

test/NameLookup/SwiftLexicalLookup/testExtensionSignature.swift

@@ -0,0 +1,31 @@
+// RUN: %target-typecheck-verify-swift -enable-experimental-feature UnqualifiedLookupValidation
+
+import SwiftShims
+
+extension Unicode.SMTH: Sequence { // expected-error{{'SMTH' is not a member type of enum 'Swift.Unicode'}}
+
+  internal consuming func makeIterator() -> Iterator {
+    Iterator(source: source.makeIterator())
+  }
+
+  internal struct Iterator: IteratorProtocol {
+
+    internal var source: Source.Iterator
+    internal var normalizer: Unicode._NFCNormalizer
+
+    internal init(source: Source.Iterator) {
+      self.source = source
+      if let strIter = source as? String.UnicodeScalarView.Iterator {
+        self.normalizer = Unicode._NFCNormalizer(sourceString: strIter._guts)
+      } else if let substrIter = source as? Substring.UnicodeScalarView.Iterator {
+        self.normalizer = Unicode._NFCNormalizer(sourceString: substrIter._elements._wholeGuts)
+      } else {
+        self.normalizer = Unicode._NFCNormalizer()
+      }
+    }
+
+    internal mutating func next() -> Unicode.Scalar? {
+      normalizer.resume { source.next() } ?? normalizer.flush()
+    }
+  }
+}