[IR] Initial stab at std::string->String upgrade (#5438)

include/tvm/ir/span.h

@@ -40,7 +40,7 @@ class SourceName;
 class SourceNameNode : public Object {
  public:
   /*! \brief The source name. */
-  std::string name;
+  String name;
   // override attr visitor
   void VisitAttrs(AttrVisitor* v) { v->Visit("name", &name); }
 
@@ -64,7 +64,7 @@ class SourceName : public ObjectRef {
    * \param name Name of the operator.
    * \return SourceName valid throughout program lifetime.
    */
-  TVM_DLL static SourceName Get(const std::string& name);
+  TVM_DLL static SourceName Get(const String& name);
 
   TVM_DEFINE_OBJECT_REF_METHODS(SourceName, ObjectRef, SourceNameNode);
 };

include/tvm/ir/type.h

@@ -227,7 +227,7 @@ class TypeVarNode : public TypeNode {
    *  this only acts as a hint to the user,
    *  and is not used for equality.
    */
-  std::string name_hint;
+  String name_hint;
   /*! \brief The kind of type parameter */
   TypeKind kind;
 
@@ -263,7 +263,7 @@ class TypeVar : public Type {
    * \param name_hint The name of the type var.
    * \param kind The kind of the type var.
    */
-  TVM_DLL TypeVar(std::string name_hint, TypeKind kind);
+  TVM_DLL TypeVar(String name_hint, TypeKind kind);
 
   TVM_DEFINE_OBJECT_REF_METHODS(TypeVar, Type, TypeVarNode);
 };

python/tvm/ir/json_compact.py

@@ -16,6 +16,9 @@
 # under the License.
 """Tool to upgrade json from historical versions."""
 import json
+import tvm.ir
+import tvm.runtime
+
 
 def create_updater(node_map, from_ver, to_ver):
     """Create an updater to update json loaded data.
@@ -41,8 +44,12 @@ def create_updater(node_map, from_ver, to_ver):
         nodes = data["nodes"]
         for idx, item in enumerate(nodes):
             f = node_map.get(item["type_key"], None)
-            if f:
-                nodes[idx] = f(item, nodes)
+            if isinstance(f, list):
+                for fpass in f:
+                    item = fpass(item, nodes)
+            elif f:
+                item = f(item, nodes)
+            nodes[idx] = item
         data["attrs"]["tvm_version"] = to_ver
         return data
     return _updater
@@ -84,12 +91,26 @@ def create_updater_06_to_07():
         del item["global_key"]
         return item
 
+    def _update_from_std_str(key):
+        def _convert(item, nodes):
+            str_val = item["attrs"][key]
+            jdata = json.loads(tvm.ir.save_json(tvm.runtime.String(str_val)))
+            root_idx = jdata["root"]
+            val = jdata["nodes"][root_idx]
+            sidx = len(nodes)
+            nodes.append(val)
+            item["attrs"][key] = '%d' % sidx
+            return item
+
+        return _convert
+
+
     node_map = {
         # Base IR
         "SourceName": _update_global_key,
         "EnvFunc": _update_global_key,
         "relay.Op": _update_global_key,
-        "relay.TypeVar": _ftype_var,
+        "relay.TypeVar": [_ftype_var, _update_from_std_str("name_hint")],
         "relay.GlobalTypeVar": _ftype_var,
         "relay.Type": _rename("Type"),
         "relay.TupleType": _rename("TupleType"),

src/ir/span.cc

@@ -25,10 +25,10 @@
 
 namespace tvm {
 
-ObjectPtr<Object> GetSourceNameNode(const std::string& name) {
+ObjectPtr<Object> GetSourceNameNode(const String& name) {
   // always return pointer as the reference can change as map re-allocate.
   // or use another level of indirection by creating a unique_ptr
-  static std::unordered_map<std::string, ObjectPtr<SourceNameNode> > source_map;
+  static std::unordered_map<String, ObjectPtr<SourceNameNode> > source_map;
 
   auto sn = source_map.find(name);
   if (sn == source_map.end()) {
@@ -41,7 +41,11 @@ ObjectPtr<Object> GetSourceNameNode(const std::string& name) {
   }
 }
 
-SourceName SourceName::Get(const std::string& name) {
+ObjectPtr<Object> GetSourceNameNodeByStr(const std::string& name) {
+  return GetSourceNameNode(name);
+}
+
+SourceName SourceName::Get(const String& name) {
   return SourceName(GetSourceNameNode(name));
 }
 
@@ -55,10 +59,10 @@ TVM_STATIC_IR_FUNCTOR(ReprPrinter, vtable)
   });
 
 TVM_REGISTER_NODE_TYPE(SourceNameNode)
-.set_creator(GetSourceNameNode)
-.set_repr_bytes([](const Object* n) {
-    return static_cast<const SourceNameNode*>(n)->name;
-  });
+.set_creator(GetSourceNameNodeByStr)
+.set_repr_bytes([](const Object* n) -> std::string {
+  return static_cast<const SourceNameNode*>(n)->name;
+});
 
 Span SpanNode::make(SourceName source, int lineno, int col_offset) {
   auto n = make_object<SpanNode>();

src/ir/type.cc

@@ -66,7 +66,7 @@ TVM_STATIC_IR_FUNCTOR(ReprPrinter, vtable)
 });
 
 
-TypeVar::TypeVar(std::string name, TypeKind kind) {
+TypeVar::TypeVar(String name, TypeKind kind) {
   ObjectPtr<TypeVarNode> n = make_object<TypeVarNode>();
   n->name_hint = std::move(name);
   n->kind = std::move(kind);
@@ -76,7 +76,7 @@ TypeVar::TypeVar(std::string name, TypeKind kind) {
 TVM_REGISTER_NODE_TYPE(TypeVarNode);
 
 TVM_REGISTER_GLOBAL("ir.TypeVar")
-.set_body_typed([](std::string name, int kind) {
+.set_body_typed([](String name, int kind) {
   return TypeVar(name, static_cast<TypeKind>(kind));
 });