ASTGen: Translate extension declarations

Author: AnthonyLatsis

include/swift/AST/CASTBridging.h

@@ -406,6 +406,12 @@ void *AssociatedTypeDecl_create(BridgedASTContext cContext,
                                 void *_Nullable opaqueDefaultType,
                                 void *_Nullable opaqueGenericWhereClause);
 
+BridgedDeclContextAndDecl ExtensionDecl_create(
+    BridgedASTContext cContext, BridgedDeclContext cDeclContext,
+    BridgedSourceLoc cExtensionKeywordLoc, void *opaqueExtendedType,
+    BridgedArrayRef cInheritedTypes, void *_Nullable opaqueGenericWhereClause,
+    BridgedSourceRange cBraceRange);
+
 void *GenericParamList_create(BridgedASTContext cContext,
                               BridgedSourceLoc cLeftAngleLoc,
                               BridgedArrayRef cParameters,

lib/AST/CASTBridging.cpp

@@ -729,6 +729,24 @@ void *AssociatedTypeDecl_create(BridgedASTContext cContext,
   return static_cast<Decl *>(decl);
 }
 
+BridgedDeclContextAndDecl ExtensionDecl_create(
+    BridgedASTContext cContext, BridgedDeclContext cDeclContext,
+    BridgedSourceLoc cExtensionKeywordLoc, void *opaqueExtendedType,
+    BridgedArrayRef cInheritedTypes, void *_Nullable opaqueGenericWhereClause,
+    BridgedSourceRange cBraceRange) {
+  ASTContext &context = convertASTContext(cContext);
+
+  auto *decl = ExtensionDecl::create(
+      context, convertSourceLoc(cExtensionKeywordLoc),
+      static_cast<TypeRepr *>(opaqueExtendedType),
+      context.AllocateCopy(convertToInheritedEntries(cInheritedTypes)),
+      convertDeclContext(cDeclContext),
+      static_cast<TrailingWhereClause *>(opaqueGenericWhereClause));
+  decl->setBraces(convertSourceRange(cBraceRange));
+
+  return {bridgeDeclContext(decl), static_cast<Decl *>(decl)};
+}
+
 void *OptionalTypeRepr_create(BridgedASTContext cContext, void *base,
                               BridgedSourceLoc cQuestionLoc) {
   ASTContext &context = convertASTContext(cContext);

lib/ASTGen/Sources/ASTGen/Decls.swift

@@ -158,6 +158,28 @@ extension ASTGenVisitor {
   }
 }
 
+// MARK: - ExtensionDecl
+
+extension ASTGenVisitor {
+  func visit(_ node: ExtensionDeclSyntax) -> ASTNode {
+    let decl = ExtensionDecl_create(
+      self.ctx,
+      self.declContext,
+      self.bridgedSourceLoc(for: node.extensionKeyword),
+      self.visit(node.extendedType).rawValue,
+      self.visit(node.inheritanceClause?.inheritedTypes),
+      self.visit(node.genericWhereClause)?.rawValue,
+      BridgedSourceRange(startToken: node.memberBlock.leftBrace, endToken: node.memberBlock.rightBrace, in: self)
+    )
+
+    self.withDeclContext(decl.asDeclContext) {
+      IterableDeclContext_setParsedMembers(self.visit(node.memberBlock.members), decl.asDecl)
+    }
+
+    return .decl(decl.asDecl)
+  }
+}
+
 // MARK: - EnumCaseDecl
 
 extension ASTGenVisitor {

test/ASTGen/verify-parse.swift

@@ -154,3 +154,8 @@ actor
 Actor<T>: Proto1 where T: Proto1 {
   func method(_ b: Bool) {}
 }
+
+extension
+Class: Proto2 where T: Proto1 {
+  func method2(_ b: Bool) {}
+}