Changeset 661214c

Timestamp:

Mar 7, 2018, 5:02:11 PM (7 years ago)

Author:

Rob Schluntz <rschlunt@…>

Branches:

ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, deferred_resn, demangler, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, with_gc

Children:

b2e8841

Parents:

02c816fc

Message:

Apply generic substitution to member type when transforming generic member expressions

File:

• src/GenPoly/Box.cc (modified) (2 diffs)

src/GenPoly/Box.cc

@@ -1587 +1587 @@
                         assert( newMemberExpr );
 
-                        Type *memberType = memberExpr->member->get_type();
+                        // Must apply the generic substitution to the member type to handle cases where the member is a generic parameter substituted by a known concrete type, e.g.
+                        //   forall(otype T) struct Box { T x; }
+                        //   forall(otype T) f() {
+                        //     Box(T *) b; b.x;
+                        //   }
+                        // TODO: memberExpr->result should be exactly memberExpr->member->get_type() after substitution, so it doesn't seem like it should be necessary to apply the substitution manually. For some reason this is not currently the case. This requires more investigation.
+                        Type *memberType = memberExpr->member->get_type()->clone();
+                        TypeSubstitution sub = objectType->genericSubstitution();
+                        sub.apply( memberType );
                         if ( ! isPolyType( memberType, scopeTyVars ) ) {
                                 // Not all members of a polymorphic type are themselves of polymorphic type; in this case the member expression should be wrapped and dereferenced to form an lvalue
@@ -1595 +1603 @@
                         }
 
+                        delete memberType;
                         delete memberExpr;
                         return newMemberExpr;