[Relay] Escape Patch that allow type inference to work without changing binding.

python/tvm/relay/transform.py

@@ -248,6 +248,30 @@ def __init__(self,
                                             passes, opt_level, name, required)
 
 
+def infer_type(expr, mod=None):
+    """Infer the type of an expr.
+    Adding Function into a Module will change it's binding,
+    and some passes need type inference to work without binding modification.
+    However, InferType() work by putting stuff into a Module, thus changing all the binding.
+
+    This is an escape patch that allow type inference without binding changing.
+
+    Parameters
+    ----------
+    expr : tvm.relay.Expr
+        The input expression.
+
+    mod : Optional[tvm.relay.Module]
+        The input module
+
+    Returns
+    -------
+    ret : tvm.relay.Expr
+        The output expression.
+    """
+    return _transform.infer_type(expr, mod)
+
+
 def InferType():
     """Infer the type of an expr.
 

src/relay/pass/type_infer.cc

@@ -824,6 +824,9 @@ Function InferType(const Function& func,
   return Downcast<Function>(func_ret);
 }
 
+TVM_REGISTER_API("relay._transform.infer_type")
+.set_body_typed<Expr(Expr, Module)>([](Expr l, Module r) { return InferType(l, r); });
+
 namespace transform {
 
 Pass InferType() {