Changeset 1cdfa82 for src/SynTree/TypeSubstitution.cc

Timestamp:

Apr 25, 2018, 4:55:53 PM (6 years ago)

Author:

Aaron Moss <a3moss@…>

Branches:

new-env, with_gc

Children:

42107b4

Parents:

2efe4b8 (diff), 9d5fb67 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge remote-tracking branch 'origin/master' into with_gc

File:

• src/SynTree/TypeSubstitution.cc (modified) (1 diff)

src/SynTree/TypeSubstitution.cc

@@ -132 +132 @@
                 return inst;
         } else {
-///         std::cerr << "found " << inst->get_name() << ", replacing with ";
-///         i->second->print( std::cerr );
-///         std::cerr << std::endl;
+                // cut off infinite loop for the case where a type is bound to itself.
+                // Note: this does not prevent cycles in the general case, so it may be necessary to do something more sophisticated here.
+                // TODO: investigate preventing type variables from being bound to themselves in the first place.
+                if ( TypeInstType * replacement = dynamic_cast< TypeInstType * >( i->second ) ) {
+                        if ( inst->name == replacement->name ) {
+                                return inst;
+                        }
+                }
+                // std::cerr << "found " << inst->name << ", replacing with " << i->second << std::endl;
                 subCount++;
                 Type * newtype = i->second->clone();
                 newtype->get_qualifiers() |= inst->get_qualifiers();
-                return newtype;
+                // Note: need to recursively apply substitution to the new type because normalize does not substitute bound vars, but bound vars must be substituted when not in freeOnly mode.
+                return newtype->acceptMutator( *visitor );
         } // if
 }