Support renaming of old types

base/reflection.jl

@@ -108,6 +108,20 @@ function resolve(g::GlobalRef; force::Bool=false)
     return g
 end
 
+function rename_binding(mod::Module, oldname::Symbol, newname::Symbol)
+    T = getfield(mod, oldname)
+    ccall(:jl_rename_binding, Void, (Any, Any, Any), mod, oldname, newname)
+    T.name.name = newname
+    T
+end
+
+function shunt_binding(mod::Module, oldname::Symbol)
+    i = oldbinding_counter[] + 1  # oldbinding_counter created in refpointer.jl
+    oldbinding_counter[] = i
+    newname = Symbol(oldname, '#', i)
+    rename_binding(mod, oldname, newname)
+end
+
 """
     fieldname(x::DataType, i::Integer)
 

base/refpointer.jl

@@ -122,3 +122,5 @@ setindex!(b::RefValue, x) = (b.x = x; b)
 setindex!(b::RefArray, x) = (b.x[b.i] = x; b)
 
 ###
+
+const oldbinding_counter = Ref(0)

src/module.c

@@ -519,6 +519,16 @@ void jl_binding_deprecation_warning(jl_binding_t *b)
     }
 }
 
+JL_DLLEXPORT void jl_rename_binding(jl_module_t *m, jl_sym_t *oldvar, jl_sym_t *newvar)
+{
+    jl_binding_t *b = jl_get_binding(m, oldvar);
+    if (b) {
+        b->name = newvar;
+        ptrhash_remove(&m->bindings, oldvar);
+        ptrhash_put(&m->bindings, newvar, b);
+    }
+}
+
 JL_DLLEXPORT void jl_checked_assignment(jl_binding_t *b, jl_value_t *rhs)
 {
     if (b->constp && b->value != NULL) {