---

yaml
---
r: 292734
b: refs/heads/tensorflow
c: 589283b
h: refs/heads/master

Author: xedin

[refs]

@@ -816,7 +816,7 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2018-04-25-a: 22f738a831d43aff2b9c9773bcb65
 refs/tags/swift-DEVELOPMENT-SNAPSHOT-2018-05-08-a: 7d98cc16689baba5c8a3b90a9329bdcc1a12b4e9
 refs/heads/cherr42: a566ad54b073c2c56ac0a705d0a5bed9743135a5
 "refs/heads/codable_test_comment_fix": fc8f6824f7f347e1e8db55bff62db385c5728b5a
-refs/heads/tensorflow: d4bbcc1953527ac5fa4238ec40aca08c49908ad7
+refs/heads/tensorflow: 589283b2c0cd1f7b6604bc5389885031fcc0dafb
 refs/tags/swift-4.1-DEVELOPMENT-SNAPSHOT-2018-05-11-a: 8126fd7a652e2f70ad6d76505239e34fb2ef3e1a
 refs/tags/swift-4.1-DEVELOPMENT-SNAPSHOT-2018-05-12-a: b3fd3dd84df6717f2e2e9df58c6d7e99fed57086
 refs/tags/swift-4.1-DEVELOPMENT-SNAPSHOT-2018-05-13-a: 71135119579039dc321c5f65d870050fe36efda2

branches/tensorflow/lib/Sema/CSGen.cpp

@@ -3274,6 +3274,38 @@ namespace {
             expr = sanitizeArgumentList(expr);
         }
 
+        // If this expression represents keypath based dynamic member
+        // lookup, let's convert it back to the original form of
+        // member or subscript reference.
+        if (auto *SE = dyn_cast<SubscriptExpr>(expr)) {
+          if (auto *TE = dyn_cast<TupleExpr>(SE->getIndex())) {
+            auto isImplicitKeyPathExpr = [](Expr *argExpr) -> bool {
+              if (auto *KP = dyn_cast<KeyPathExpr>(argExpr))
+                return KP->isImplicit();
+              return false;
+            };
+
+            if (TE->isImplicit() && TE->getNumElements() == 1 &&
+                TE->getElementName(0) == TC.Context.Id_dynamicMember &&
+                isImplicitKeyPathExpr(TE->getElement(0))) {
+              auto *keyPathExpr = cast<KeyPathExpr>(TE->getElement(0));
+              auto *componentExpr = keyPathExpr->getParsedPath();
+
+              if (auto *UDE = dyn_cast<UnresolvedDotExpr>(componentExpr)) {
+                UDE->setBase(SE->getBase());
+                return {true, UDE};
+              }
+
+              if (auto *subscript = dyn_cast<SubscriptExpr>(componentExpr)) {
+                subscript->setBase(SE->getBase());
+                return {true, subscript};
+              }
+
+              llvm_unreachable("unknown keypath component type");
+            }
+          }
+        }
+
         // Now, we're ready to walk into sub expressions.
         return {true, expr};
       }
@@ -3898,4 +3930,4 @@ swift::getOriginalArgumentList(Expr *expr) {
   }
 
   return result;
-}
+}