[REFACTOR][IR] Move to runtime::String (#5276)

* Use runtime::String

* move string to tvm namespace

* add const char* constructor

* implicit cast from std::string

include/tvm/ir/expr.h

@@ -107,11 +107,12 @@ class PrimExpr : public BaseExpr {
    * \param value The value to be constructed.
    */
   TVM_DLL PrimExpr(float value);  // NOLINT(*)
+
   /*!
-   * \brief construct from string.
-   * \param str The value to be constructed.
+   * \brief construct from runtime String.
+   * \param value The value to be constructed.
    */
-  TVM_DLL PrimExpr(std::string str);  // NOLINT(*)
+  TVM_DLL PrimExpr(runtime::String value);  // NOLINT(*)
 
   /*! \return the data type of this expression. */
   DataType dtype() const {

include/tvm/ir/transform.h

@@ -57,6 +57,7 @@
 #define TVM_IR_TRANSFORM_H_
 
 #include <tvm/support/with.h>
+#include <tvm/runtime/container.h>
 #include <tvm/node/container.h>
 #include <tvm/ir/error.h>
 #include <tvm/ir/module.h>
@@ -95,9 +96,9 @@ class PassContextNode : public Object {
   int fallback_device{static_cast<int>(kDLCPU)};
 
   /*! \brief The list of required passes. */
-  Array<PrimExpr> required_pass;
+  Array<runtime::String> required_pass;
   /*! \brief The list of disabled passes. */
-  Array<PrimExpr> disabled_pass;
+  Array<runtime::String> disabled_pass;
 
   TraceFunc trace_func;
 
@@ -197,7 +198,7 @@ class PassInfoNode : public Object {
   std::string name;
 
   /*! \brief The passes that are required to perform the current pass. */
-  Array<PrimExpr> required;
+  Array<runtime::String> required;
 
   PassInfoNode() = default;
 
@@ -226,7 +227,7 @@ class PassInfo : public ObjectRef {
    */
   TVM_DLL PassInfo(int opt_level,
                    std::string name,
-                   Array<PrimExpr> required);
+                   Array<runtime::String> required);
 
   TVM_DEFINE_OBJECT_REF_METHODS(PassInfo, ObjectRef, PassInfoNode);
 };
@@ -346,7 +347,7 @@ Pass CreateModulePass(
     const runtime::TypedPackedFunc<IRModule(IRModule, PassContext)>& pass_func,
     int opt_level,
     const std::string& name,
-    const Array<PrimExpr>& required);
+    const Array<runtime::String>& required);
 
 }  // namespace transform
 }  // namespace tvm

include/tvm/node/container.h

@@ -36,6 +36,8 @@
 
 namespace tvm {
 
+using runtime::String;
+using runtime::StringObj;
 using runtime::Object;
 using runtime::ObjectPtr;
 using runtime::ObjectRef;

include/tvm/node/node.h

@@ -35,6 +35,7 @@
 #define TVM_NODE_NODE_H_
 
 #include <tvm/runtime/c_runtime_api.h>
+#include <tvm/runtime/container.h>
 #include <tvm/runtime/object.h>
 #include <tvm/runtime/memory.h>
 #include <tvm/node/reflection.h>
@@ -62,6 +63,7 @@ using runtime::make_object;
 using runtime::PackedFunc;
 using runtime::TVMArgs;
 using runtime::TVMRetValue;
+using runtime::String;
 
 }  // namespace tvm
 #endif  // TVM_NODE_NODE_H_

include/tvm/relay/transform.h

@@ -24,6 +24,7 @@
 #ifndef TVM_RELAY_TRANSFORM_H_
 #define TVM_RELAY_TRANSFORM_H_
 
+#include <tvm/runtime/container.h>
 #include <tvm/relay/attrs/transform.h>
 #include <tvm/ir/transform.h>
 #include <tvm/relay/expr.h>
@@ -59,7 +60,7 @@ TVM_DLL Pass CreateFunctionPass(const runtime::TypedPackedFunc<
                                 Function(Function, IRModule, PassContext)>& pass_func,
                                 int opt_level,
                                 const std::string& name,
-                                const tvm::Array<tvm::PrimExpr>& required);
+                                const tvm::Array<runtime::String>& required);
 
 /*! \brief Remove expressions which does not effect the program result.
  *
@@ -355,7 +356,7 @@ TVM_DLL Pass Inline();
  *
  * \return The pass.
  */
-TVM_DLL Pass RemoveUnusedFunctions(Array<tvm::PrimExpr> entry_functions);
+TVM_DLL Pass RemoveUnusedFunctions(Array<runtime::String> entry_functions);
 
 }  // namespace transform
 

include/tvm/runtime/container.h

@@ -360,7 +360,15 @@ class String : public ObjectRef {
    * \note If user passes const reference, it will trigger copy. If it's rvalue,
    * it will be moved into other.
    */
-  explicit String(std::string other);
+  String(std::string other);  // NOLINT(*)
+
+  /*!
+   * \brief Construct a new String object
+   *
+   * \param other a char array.
+   */
+  String(const char* other)  // NOLINT(*)
+      : String(std::string(other)) {}
 
   /*!
    * \brief Change the value the reference object points to.

include/tvm/target/target.h

@@ -52,11 +52,11 @@ class TargetNode : public Object {
   /*! \brief The warp size that should be used by the LowerThreadAllreduce pass */
   int thread_warp_size = 1;
   /*! \brief Keys for this target */
-  Array<PrimExpr> keys_array;
+  Array<runtime::String> keys_array;
   /*! \brief Options for this target */
-  Array<PrimExpr> options_array;
+  Array<runtime::String> options_array;
   /*! \brief Collection of imported libs */
-  Array<PrimExpr> libs_array;
+  Array<runtime::String> libs_array;
 
   /*! \return the full device string to pass to codegen::Build */
   TVM_DLL const std::string& str() const;

include/tvm/tir/stmt_functor.h

@@ -326,15 +326,15 @@ class StmtExprMutator :
  *          won't do further recursion.
  * \param postorder The function called after recursive mutation.
  *          The recursive mutation result is passed to postorder for further mutation.
- * \param only_enable List of StringImm.
+ * \param only_enable List of runtime::String.
  *          If it is empty, all IRNode will call preorder/postorder
  *          If it is not empty, preorder/postorder will only be called
  *          when the IRNode's type key is in the list.
  */
 TVM_DLL Stmt IRTransform(Stmt node,
                          const runtime::PackedFunc& preorder,
                          const runtime::PackedFunc& postorder,
-                         const Array<PrimExpr>& only_enable = {});
+                         const Array<runtime::String>& only_enable = {});
 
 /*!
  * \brief recursively visit the ir in post DFS order node, apply fvisit

include/tvm/tir/transform.h

@@ -56,7 +56,7 @@ TVM_DLL Pass CreatePrimFuncPass(const runtime::TypedPackedFunc<
                                 PrimFunc(PrimFunc, IRModule, PassContext)>& pass_func,
                                 int opt_level,
                                 const std::string& name,
-                                const tvm::Array<tvm::PrimExpr>& required);
+                                const tvm::Array<runtime::String>& required);
 
 /*!
  * \brief Transform the high-level PrimFunc to a low-level version
@@ -100,7 +100,7 @@ TVM_DLL Pass MakePackedAPI(int num_unpacked_args);
  *
  * \return The pass.
  */
-TVM_DLL Pass RemapThreadAxis(Map<PrimExpr, IterVar> axis_map);
+TVM_DLL Pass RemapThreadAxis(Map<runtime::String, IterVar> axis_map);
 
 
 /*!

python/tvm/autotvm/task/task.py

@@ -24,6 +24,7 @@
 import numpy as np
 
 from tvm import target as _target
+from tvm import runtime
 from tvm.ir import container
 from tvm.tir import expr
 from tvm.te import tensor, placeholder
@@ -55,6 +56,8 @@ def _encode(x):
             return x
         if isinstance(x, (expr.StringImm, expr.IntImm, expr.FloatImm)):
             return x.value
+        if isinstance(x, runtime.container.String):
+            return str(x)
         if x is None:
             return None
         raise RuntimeError('Do not support type "%s" in argument. Consider to use'

python/tvm/relay/backend/graph_runtime_codegen.py

@@ -84,8 +84,7 @@ def codegen(self, func):
         lowered_func = self._get_irmodule()
         param_names = self._list_params_name()
         params = {}
-        for name in param_names:
-            key = name.value
+        for key in param_names:
             arr = self._get_param_by_name(key)
             param = empty(arr.shape, dtype=arr.dtype, ctx=arr.ctx)
             arr.copyto(param)

python/tvm/runtime/container.py

@@ -16,8 +16,9 @@
 # under the License.
 """Runtime container structures."""
 import tvm._ffi
-
+from tvm._ffi.base import string_types
 from tvm.runtime import Object, ObjectTypes
+from tvm.runtime import _ffi_api
 
 def getitem_helper(obj, elem_getter, length, idx):
     """Helper function to implement a pythonic getitem function.
@@ -75,18 +76,19 @@ def __init__(self, tag, fields):
         for f in fields:
             assert isinstance(f, ObjectTypes), "Expect object or " \
             "tvm NDArray type, but received : {0}".format(type(f))
-        self.__init_handle_by_constructor__(_ADT, tag, *fields)
+        self.__init_handle_by_constructor__(_ffi_api.ADT, tag,
+                                            *fields)
 
     @property
     def tag(self):
-        return _GetADTTag(self)
+        return _ffi_api.GetADTTag(self)
 
     def __getitem__(self, idx):
         return getitem_helper(
-            self, _GetADTFields, len(self), idx)
+            self, _ffi_api.GetADTFields, len(self), idx)
 
     def __len__(self):
-        return _GetADTSize(self)
+        return _ffi_api.GetADTSize(self)
 
 
 def tuple_object(fields=None):
@@ -106,7 +108,7 @@ def tuple_object(fields=None):
     for f in fields:
         assert isinstance(f, ObjectTypes), "Expect object or tvm " \
         "NDArray type, but received : {0}".format(type(f))
-    return _Tuple(*fields)
+    return _ffi_api.Tuple(*fields)
 
 
 @tvm._ffi.register_object("runtime.String")
@@ -115,7 +117,7 @@ class String(Object):
 
     Parameters
     ----------
-    string : Str
+    string : str
         The string used to construct a runtime String object
 
     Returns
@@ -124,7 +126,50 @@ class String(Object):
         The created object.
     """
     def __init__(self, string):
-        self.__init_handle_by_constructor__(_String, string)
+        self.__init_handle_by_constructor__(_ffi_api.String, string)
+
+    def __str__(self):
+        return _ffi_api.GetStdString(self)
+
+    def __len__(self):
+        return _ffi_api.GetStringSize(self)
+
+    def __hash__(self):
+        return _ffi_api.StringHash(self)
+
+    def __eq__(self, other):
+        if isinstance(other, string_types):
+            return self.__str__() == other
+
+        if not isinstance(other, String):
+            return False
+
+        return _ffi_api.CompareString(self, other) == 0
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __gt__(self, other):
+        return _ffi_api.CompareString(self, other) > 0
+
+    def __lt__(self, other):
+        return _ffi_api.CompareString(self, other) < 0
+
+    def __getitem__(self, key):
+        return self.__str__()[key]
+
+    def startswith(self, string):
+        """Check if the runtime string starts with a given string
 
+        Parameters
+        ----------
+        string : str
+            The provided string
 
-tvm._ffi._init_api("tvm.runtime.container")
+        Returns
+        -------
+        ret : boolean
+            Return true if the runtime string starts with the given string,
+        otherwise, false.
+        """
+        return self.__str__().startswith(string)

python/tvm/runtime/object_generic.py

@@ -19,7 +19,7 @@
 from numbers import Number, Integral
 from tvm._ffi.base import string_types
 
-from . import _ffi_node_api
+from . import _ffi_node_api, _ffi_api
 from .object import ObjectBase, _set_class_object_generic
 from .ndarray import NDArrayBase
 from .packed_func import PackedFuncBase, convert_to_tvm_func
@@ -56,7 +56,7 @@ def convert_to_object(value):
     if isinstance(value, Number):
         return const(value)
     if isinstance(value, string_types):
-        return _ffi_node_api.String(value)
+        return _ffi_api.String(value)
     if isinstance(value, (list, tuple)):
         value = [convert_to_object(x) for x in value]
         return _ffi_node_api.Array(*value)

python/tvm/target/target.py

@@ -48,26 +48,26 @@ def __new__(cls):
     @property
     def keys(self):
         if not self._keys:
-            self._keys = [k.value for k in self.keys_array]
+            self._keys = [str(k) for k in self.keys_array]
         return self._keys
 
     @property
     def options(self):
         if not self._options:
-            self._options = [o.value for o in self.options_array]
+            self._options = [str(o) for o in self.options_array]
         return self._options
 
     @property
     def libs(self):
         if not self._libs:
-            self._libs = [l.value for l in self.libs_array]
+            self._libs = [str(l) for l in self.libs_array]
         return self._libs
 
     @property
     def model(self):
         for opt in self.options_array:
-            if opt.value.startswith('-model='):
-                return opt.value[7:]
+            if opt.startswith('-model='):
+                return opt[7:]
         return 'unknown'
 
     @property

src/autotvm/touch_extractor.cc

@@ -252,9 +252,9 @@ void GetItervarFeature(Stmt stmt, bool take_log, Array<Array<Array<PrimExpr> > >
   for (auto var : vars) {
     Array<Array<PrimExpr> > feature_row;
     ItervarFeature &fea = touch_analyzer.itervar_map[var];
-    feature_row.push_back(Array<PrimExpr>{std::string("_itervar_"), var});
+    feature_row.push_back(Array<PrimExpr>{tvm::tir::StringImmNode::make("_itervar_"), var});
 
-    Array<PrimExpr> attr{std::string("_attr_"),
+    Array<PrimExpr> attr{tvm::tir::StringImmNode::make("_attr_"),
                      FloatImm(DataType::Float(32), trans(fea.length)),
                      IntImm(DataType::Int(32), fea.nest_level),
                      FloatImm(DataType::Float(32), trans(fea.topdown_product)),
@@ -267,7 +267,7 @@ void GetItervarFeature(Stmt stmt, bool take_log, Array<Array<Array<PrimExpr> > >
     feature_row.push_back(attr);
 
     // arithmetic
-    feature_row.push_back(Array<PrimExpr>{std::string("_arith_"),
+    feature_row.push_back(Array<PrimExpr>{tvm::tir::StringImmNode::make("_arith_"),
             FloatImm(DataType::Float(32), trans(fea.add_ct)),
             FloatImm(DataType::Float(32), trans(fea.mul_ct)),
             FloatImm(DataType::Float(32), trans(fea.div_ct)),
@@ -282,7 +282,7 @@ void GetItervarFeature(Stmt stmt, bool take_log, Array<Array<Array<PrimExpr> > >
     for (auto k : bufs) {
       TouchPattern &v = fea.touch_feature[k];
       feature_row.push_back(
-          Array<PrimExpr>{k,
+          Array<PrimExpr>{tvm::tir::StringImmNode::make(k),
                 FloatImm(DataType::Float(32), trans(v.stride)),
                 FloatImm(DataType::Float(32), trans(v.mod)),
                 FloatImm(DataType::Float(32), trans(v.count)),