[ASTGen] Implement DotSelfExpr generation

Author: rintaro

include/swift/AST/ASTBridging.h

@@ -661,6 +661,12 @@ BridgedCallExpr BridgedCallExpr_createParsed(BridgedASTContext cContext,
                                              BridgedExpr fn,
                                              BridgedTupleExpr args);
 
+SWIFT_NAME("BridgedDotSelfExpr.createParsed(_:subExpr:dotLoc:selfLoc:)")
+BridgedDotSelfExpr BridgedDotSelfExpr_createParsed(BridgedASTContext cContext,
+                                                   BridgedExpr cSubExpr,
+                                                   BridgedSourceLoc cDotLoc,
+                                                   BridgedSourceLoc cSelfLoc);
+
 SWIFT_NAME("BridgedClosureExpr.createParsed(_:declContext:body:)")
 BridgedClosureExpr
 BridgedClosureExpr_createParsed(BridgedASTContext cContext,

lib/AST/ASTBridging.cpp

@@ -925,6 +925,15 @@ BridgedForcedCheckedCastExpr BridgedForcedCheckedCastExpr_createParsed(
                                        cType.unbridged());
 }
 
+BridgedDotSelfExpr BridgedDotSelfExpr_createParsed(BridgedASTContext cContext,
+                                                   BridgedExpr cSubExpr,
+                                                   BridgedSourceLoc cDotLoc,
+                                                   BridgedSourceLoc cSelfLoc) {
+
+  return new (cContext.unbridged()) DotSelfExpr(
+      cSubExpr.unbridged(), cDotLoc.unbridged(), cSelfLoc.unbridged());
+}
+
 BridgedIsExpr BridgedIsExpr_createParsed(BridgedASTContext cContext,
                                          BridgedSourceLoc cIsLoc,
                                          BridgedTypeRepr cType) {

lib/ASTGen/Sources/ASTGen/Exprs.swift

@@ -348,20 +348,33 @@ extension ASTGenVisitor {
   }
 
   func generate(memberAccessExpr node: MemberAccessExprSyntax) -> BridgedExpr {
+    let dotLoc = self.generateSourceLoc(node.period)
     let nameAndLoc = createDeclNameRef(declReferenceExpr: node.declName)
 
     if let base = node.base {
-      return BridgedUnresolvedDotExpr.createParsed(
-        self.ctx,
-        base: self.generate(expr: base),
-        dotLoc: self.generateSourceLoc(node.period),
-        name: nameAndLoc.name,
-        nameLoc: nameAndLoc.loc
-      ).asExpr
+      if node.declName.baseName.keywordKind == .`self` {
+        // TODO: Diagnose if there's arguments
+        assert(node.declName.argumentNames == nil)
+
+        return BridgedDotSelfExpr.createParsed(
+          self.ctx,
+          subExpr: self.generate(expr: base),
+          dotLoc: dotLoc,
+          selfLoc: self.generateSourceLoc(node.declName)
+        ).asExpr
+      } else {
+        return BridgedUnresolvedDotExpr.createParsed(
+          self.ctx,
+          base: self.generate(expr: base),
+          dotLoc: dotLoc,
+          name: nameAndLoc.name,
+          nameLoc: nameAndLoc.loc
+        ).asExpr
+      }
     } else {
       return BridgedUnresolvedMemberExpr.createParsed(
         self.ctx,
-        dotLoc: self.generateSourceLoc(node.period),
+        dotLoc: dotLoc,
         name: nameAndLoc.name,
         nameLoc: nameAndLoc.loc
       ).asExpr

test/ASTGen/verify-parse.swift

@@ -207,9 +207,15 @@ precedencegroup Precedence2 {
 struct TestStruct {
   func method(arg: Int, _ c: Int) {}
 
+  enum Ty {
+    case `self`
+    case `Self`
+  }
+
   func test() {
     _ = method(arg:_:)
-    _ = self.method(arg:_:)
+    _ = self.method(arg:_:).self
+    _ = Ty.`Self` ==  Ty.`self`
   }
 
 // FIXME: Compute 'static' location