Fix copy elision on nested tuple expr

Signed-off-by: Anna Rift <[email protected]>

Author: arifthpe

frontend/lib/resolution/copy-elision.cpp

@@ -391,20 +391,11 @@ void FindElidedCopies::handleDeclaration(const VarLikeDecl* ast,
                             isFormal, rv);
         } else {
           ID rhsVarId = refersToId(eltExpr, rv);
+          QualifiedType rhsType = rv.byId(rhsVarId).type();
           if (!rhsVarId.isEmpty() && isEligibleVarInAnyFrame(rhsVarId)) {
-            // check that the types are the same, per tuple position
-            if (rv.hasId(lhsVarId) && rv.hasId(rhsVarId)) {
-              if (lhsType.type() && lhsType.type()->isTupleType()) {
-                const TupleType* ttype = lhsType.type()->toTupleType();
-                CHPL_ASSERT(ttype->numElements() ==
-                            tupleExprInit->numActuals());
-                QualifiedType lhsEltType = ttype->elementType(i);
-
-                QualifiedType rhsType = rv.byId(rhsVarId).type();
-                if (copyElisionAllowedForTypes(lhsEltType, rhsType, ast, rv)) {
-                  addCopyInit(frame, rhsVarId, eltExpr->id());
-                }
-              }
+            // TODO: do we need to verify LHS and RHS type compatibility per element?
+            if (copyElisionAllowedForTypes(rhsType, rhsType, ast, rv)) {
+              addCopyInit(frame, rhsVarId, eltExpr->id());
             }
           }
         }

frontend/test/resolution/testCopyElision.cpp

@@ -1385,13 +1385,22 @@ static void test49() {
       record R { }
       proc test() {
         var r = new R();
+        var s = new R();
 
-        var tup = (1, r, "hi");
+        var tup = ((1,), r, ((s, "hi"), 2, 3.14));
 
-        var (a, b, _) = tup;
+        var ((a,), b, ((c, d), _, e)) = tup;
       }
     )"""",
-    {"M.test@5", "M.test@9", "M.test@10"});
+    {
+      "M.test@10",
+      "M.test@11",
+      "M.test@19",
+      "M.test@21",
+      "M.test@22",
+      "M.test@23",
+      "M.test@26",
+    });
 
   // Assign
   testCopyElision("test49b",