[TVMScript] Doc Base Class & DocPrinter Scaffolding (apache#11971)

This PR addes:
- Doc base class
- DocPrinter base class
- PythonDocPrinter
- LiteralDoc and its support in DocPrinter

Tracking issue: apache#11912

CMakeLists.txt

@@ -281,6 +281,7 @@ tvm_file_glob(GLOB_RECURSE COMPILER_SRCS
     src/parser/*.cc
     src/printer/*.cc
     src/support/*.cc
+    src/script/*.cc
     )
 
 tvm_file_glob(GLOB CODEGEN_SRCS

include/tvm/script/printer/doc.h

@@ -0,0 +1,165 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+#ifndef TVM_SCRIPT_PRINTER_DOC_H_
+#define TVM_SCRIPT_PRINTER_DOC_H_
+
+#include <tvm/ir/expr.h>
+#include <tvm/node/node.h>
+#include <tvm/runtime/data_type.h>
+
+namespace tvm {
+namespace script {
+namespace printer {
+
+/*!
+ * \brief The base class of all Doc.
+ *
+ * Doc is an intermediate representation between IR from TVM
+ * and the TVMScript code.
+ * During printing, IR graph is first translated into Doc tree,
+ * then the Doc tree is translated to the target language in
+ * text format.
+ *
+ * \sa Doc
+ */
+class DocNode : public Object {
+ public:
+  void VisitAttrs(AttrVisitor* v) {}
+
+  static constexpr const char* _type_key = "script.printer.Doc";
+  TVM_DECLARE_BASE_OBJECT_INFO(DocNode, Object);
+
+ public:
+  virtual ~DocNode() = default;
+};
+
+/*!
+ * \brief Reference type of DocNode.
+ *
+ * \sa DocNode
+ */
+class Doc : public ObjectRef {
+ protected:
+  Doc() = default;
+
+ public:
+  virtual ~Doc() = default;
+  TVM_DEFINE_NOTNULLABLE_OBJECT_REF_METHODS(Doc, ObjectRef, DocNode);
+};
+
+/*!
+ * \brief The base class of expression doc.
+ *
+ * \sa ExprDoc
+ */
+class ExprDocNode : public DocNode {
+ public:
+  void VisitAttrs(AttrVisitor* v) { DocNode::VisitAttrs(v); }
+
+  static constexpr const char* _type_key = "script.printer.ExprDoc";
+  TVM_DECLARE_BASE_OBJECT_INFO(ExprDocNode, DocNode);
+};
+
+/*!
+ * \brief Reference type of ExprDocNode.
+ *
+ * \sa ExprDocNode
+ */
+class ExprDoc : public Doc {
+ protected:
+  ExprDoc() = default;
+
+ public:
+  TVM_DEFINE_NOTNULLABLE_OBJECT_REF_METHODS(ExprDoc, Doc, ExprDocNode);
+};
+
+/*!
+ * \brief Doc that represents literal value.
+ *
+ * \sa LiteralDoc
+ */
+class LiteralDocNode : public ExprDocNode {
+ public:
+  /*!
+   * \brief the internal representation of the literal value.
+   *
+   * Possible actual types:
+   * - IntImm (integer or boolean)
+   * - FloatImm
+   * - String
+   * - null
+   */
+  ObjectRef value;
+
+  void VisitAttrs(AttrVisitor* v) {
+    ExprDocNode::VisitAttrs(v);
+    v->Visit("value", &value);
+  }
+
+  static constexpr const char* _type_key = "script.printer.LiteralDoc";
+  TVM_DECLARE_FINAL_OBJECT_INFO(LiteralDocNode, ExprDocNode);
+};
+
+/*!
+ * \brief Reference type of LiteralDocNode.
+ *
+ * \sa LiteralDocNode
+ */
+class LiteralDoc : public ExprDoc {
+ protected:
+  explicit LiteralDoc(ObjectRef value);
+
+ public:
+  /*!
+   * \brief Create a LiteralDoc to represent None/null/empty value.
+   */
+  static LiteralDoc None() { return LiteralDoc(ObjectRef(nullptr)); }
+
+  /*!
+   * \brief Create a LiteralDoc to represent integer.
+   * \param v The integer value.
+   */
+  static LiteralDoc Int(int v) { return LiteralDoc(IntImm(DataType::Int(64), v)); }
+
+  /*!
+   * \brief Create a LiteralDoc to represent boolean.
+   * \param v The boolean value.
+   */
+  static LiteralDoc Boolean(bool v) { return LiteralDoc(IntImm(DataType::Bool(), v)); }
+
+  /*!
+   * \brief Create a LiteralDoc to represent float.
+   * \param v The float value.
+   */
+  static LiteralDoc Float(double v) { return LiteralDoc(FloatImm(DataType::Float(64), v)); }
+
+  /*!
+   * \brief Create a LiteralDoc to represent string.
+   * \param v The string value.
+   */
+  static LiteralDoc Str(const String& v) { return LiteralDoc(v); }
+
+  TVM_DEFINE_NOTNULLABLE_OBJECT_REF_METHODS(LiteralDoc, ExprDoc, LiteralDocNode);
+};
+
+}  // namespace printer
+}  // namespace script
+}  // namespace tvm
+
+#endif  // TVM_SCRIPT_PRINTER_DOC_H_

include/tvm/script/printer/doc_printer.h

@@ -0,0 +1,43 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+#ifndef TVM_SCRIPT_PRINTER_DOC_PRINTER_H_
+#define TVM_SCRIPT_PRINTER_DOC_PRINTER_H_
+
+#include <tvm/script/printer/doc.h>
+
+namespace tvm {
+namespace script {
+namespace printer {
+
+/*!
+ * \brief Convert Doc into Python script.
+ *
+ * This function unpacks the DocPrinterOptions into function arguments
+ * to be FFI friendly.
+ *
+ * \param doc the doc to be converted
+ * \param indent_spaces the number of spaces used for indention
+ */
+String DocToPythonScript(Doc doc, int indent_spaces = 4);
+
+}  // namespace printer
+}  // namespace script
+}  // namespace tvm
+
+#endif  // TVM_SCRIPT_PRINTER_DOC_PRINTER_H_

python/tvm/script/printer/__init__.py

@@ -0,0 +1,26 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+TVMScript Unified Printer
+
+This package provides a set of APIs to print supported TVM IR into TVMScript
+in a roundtrippable way.
+
+https://github.com/apache/tvm-rfcs/blob/main/rfcs/0074-tvmscript-unified-printer.md
+"""
+
+from . import _ffi_api

python/tvm/script/printer/_ffi_api.py

@@ -0,0 +1,20 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""FFI APIs for tvm.script.printer"""
+import tvm._ffi
+
+tvm._ffi._init_api("script.printer", __name__)

python/tvm/script/printer/doc.py

@@ -0,0 +1,49 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""Doc types for TVMScript Unified Printer"""
+
+import tvm._ffi
+from tvm.runtime import Object
+
+from . import _ffi_api
+
+
+class Doc(Object):
+    """Base class of all Docs"""
+
+
+class ExprDoc(Object):
+    """Base class of all expression Docs"""
+
+
+@tvm._ffi.register_object("script.printer.LiteralDoc")
+class LiteralDoc(ExprDoc):
+    """Doc that represents literal value"""
+
+    def __init__(self, value):
+        if value is None:
+            self.__init_handle_by_constructor__(_ffi_api.LiteralDocNone)  # type: ignore
+        elif isinstance(value, str):
+            self.__init_handle_by_constructor__(_ffi_api.LiteralDocStr, value)  # type: ignore
+        elif isinstance(value, float):
+            self.__init_handle_by_constructor__(_ffi_api.LiteralDocFloat, value)  # type: ignore
+        elif isinstance(value, bool):
+            self.__init_handle_by_constructor__(_ffi_api.LiteralDocBoolean, value)  # type: ignore
+        elif isinstance(value, int):
+            self.__init_handle_by_constructor__(_ffi_api.LiteralDocInt, value)  # type: ignore
+        else:
+            raise TypeError(f"Unsupported type {type(value)} for LiteralDoc")

python/tvm/script/printer/doc_printer.py

@@ -0,0 +1,39 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""Functions to print doc into text format"""
+
+from . import _ffi_api
+from .doc import Doc
+
+
+def to_python_script(doc: Doc, indent_spaces: int = 4) -> str:
+    """
+    Convert Doc into Python script.
+
+    Parameters
+    ----------
+    doc : Doc
+        The doc to convert into Python script
+    indent_spaces : int
+        The number of indent spaces to use in the output
+
+    Returns
+    -------
+    script : str
+        The text representation of Doc in Python syntax
+    """
+    return _ffi_api.DocToPythonScript(doc, indent_spaces)  # type: ignore