Move driver wrappers generation to tf-psa-crypto

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/tf-psa-crypto/scripts/generate_driver_wrappers.py b/tf-psa-crypto/scripts/generate_driver_wrappers.py
new file mode 100755
index 0000000..7f5be2a
--- /dev/null
+++ b/tf-psa-crypto/scripts/generate_driver_wrappers.py
@@ -0,0 +1,216 @@
+#!/usr/bin/env python3
+"""Generate psa_crypto_driver_wrappers.h
+            psa_crypto_driver_wrappers_no_static.c
+
+   This module is invoked by the build scripts to auto generate the
+   psa_crypto_driver_wrappers.h and psa_crypto_driver_wrappers_no_static
+   based on template files in script/data_files/driver_templates/.
+"""
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+
+import sys
+import os
+import json
+from typing import NewType, Dict, Any
+from traceback import format_tb
+import argparse
+import jsonschema
+import jinja2
+
+import framework_scripts_path # pylint: disable=unused-import
+from mbedtls_framework import build_tree
+
+JSONSchema = NewType('JSONSchema', object)
+# The Driver is an Object, but practically it's indexable and can called a dictionary to
+# keep MyPy happy till MyPy comes with a more composite type for JsonObjects.
+Driver = NewType('Driver', dict)
+
+
+class JsonValidationException(Exception):
+    def __init__(self, message="Json Validation Failed"):
+        self.message = message
+        super().__init__(self.message)
+
+
+class DriverReaderException(Exception):
+    def __init__(self, message="Driver Reader Failed"):
+        self.message = message
+        super().__init__(self.message)
+
+
+def render(template_path: str, driver_jsoncontext: list) -> str:
+    """
+    Render template from the input file and driver JSON.
+    """
+    environment = jinja2.Environment(
+        loader=jinja2.FileSystemLoader(os.path.dirname(template_path)),
+        keep_trailing_newline=True)
+    template = environment.get_template(os.path.basename(template_path))
+
+    return template.render(drivers=driver_jsoncontext)
+
+def generate_driver_wrapper_file(template_dir: str,
+                                 output_dir: str,
+                                 template_file_name: str,
+                                 driver_jsoncontext: list) -> None:
+    """
+    Generate the file psa_crypto_driver_wrapper.c.
+    """
+    driver_wrapper_template_filename = \
+        os.path.join(template_dir, template_file_name)
+
+    result = render(driver_wrapper_template_filename, driver_jsoncontext)
+
+    with open(file=os.path.join(output_dir, os.path.splitext(template_file_name)[0]),
+              mode='w',
+              encoding='UTF-8') as out_file:
+        out_file.write(result)
+
+
+def validate_json(driverjson_data: Driver, driverschema_list: dict) -> None:
+    """
+    Validate the Driver JSON against an appropriate schema
+    the schema passed could be that matching an opaque/ transparent driver.
+    """
+    driver_type = driverjson_data["type"]
+    driver_prefix = driverjson_data["prefix"]
+    try:
+        _schema = driverschema_list[driver_type]
+        jsonschema.validate(instance=driverjson_data, schema=_schema)
+    except KeyError as err:
+        # This could happen if the driverjson_data.type does not exist in the provided schema list
+        # schemas = {'transparent': transparent_driver_schema, 'opaque': opaque_driver_schema}
+        # Print onto stdout and stderr.
+        print("Unknown Driver type " + driver_type +
+              " for driver " + driver_prefix, str(err))
+        print("Unknown Driver type " + driver_type +
+              " for driver " + driver_prefix, str(err), file=sys.stderr)
+        raise JsonValidationException() from err
+
+    except jsonschema.exceptions.ValidationError as err:
+        # Print onto stdout and stderr.
+        print("Error: Failed to validate data file: {} using schema: {}."
+              "\n Exception Message: \"{}\""
+              " ".format(driverjson_data, _schema, str(err)))
+        print("Error: Failed to validate data file: {} using schema: {}."
+              "\n Exception Message: \"{}\""
+              " ".format(driverjson_data, _schema, str(err)), file=sys.stderr)
+        raise JsonValidationException() from err
+
+
+def load_driver(schemas: Dict[str, Any], driver_file: str) -> Any:
+    """loads validated json driver"""
+    with open(file=driver_file, mode='r', encoding='UTF-8') as f:
+        json_data = json.load(f)
+        try:
+            validate_json(json_data, schemas)
+        except JsonValidationException as e:
+            raise DriverReaderException from e
+        return json_data
+
+
+def load_schemas(project_root: str) -> Dict[str, Any]:
+    """
+    Load schemas map
+    """
+    schema_file_paths = {
+        'transparent': os.path.join(project_root,
+                                    'scripts',
+                                    'data_files',
+                                    'driver_jsons',
+                                    'driver_transparent_schema.json'),
+        'opaque': os.path.join(project_root,
+                               'scripts',
+                               'data_files',
+                               'driver_jsons',
+                               'driver_opaque_schema.json')
+    }
+    driver_schema = {}
+    for key, file_path in schema_file_paths.items():
+        with open(file=file_path, mode='r', encoding='UTF-8') as file:
+            driver_schema[key] = json.load(file)
+    return driver_schema
+
+
+def read_driver_descriptions(project_root: str,
+                             json_directory: str,
+                             jsondriver_list: str) -> list:
+    """
+    Merge driver JSON files into a single ordered JSON after validation.
+    """
+    driver_schema = load_schemas(project_root)
+
+    with open(file=os.path.join(json_directory, jsondriver_list),
+              mode='r',
+              encoding='UTF-8') as driver_list_file:
+        driver_list = json.load(driver_list_file)
+
+    return [load_driver(schemas=driver_schema,
+                        driver_file=os.path.join(json_directory, driver_file_name))
+            for driver_file_name in driver_list]
+
+
+def trace_exception(e: Exception, file=sys.stderr) -> None:
+    """Prints exception trace to the given TextIO handle"""
+    print("Exception: type: %s, message: %s, trace: %s" % (
+        e.__class__, str(e), format_tb(e.__traceback__)
+    ), file)
+
+
+TEMPLATE_FILENAMES = ["psa_crypto_driver_wrappers.h.jinja",
+                      "psa_crypto_driver_wrappers_no_static.c.jinja"]
+
+def main() -> int:
+    """
+    Main with command line arguments.
+    """
+    def_arg_project_root = build_tree.guess_project_root()
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--project-root', default=def_arg_project_root,
+                        help='root directory of repo source code')
+    parser.add_argument('--template-dir',
+                        help='directory holding the driver templates')
+    parser.add_argument('--json-dir',
+                        help='directory holding the driver JSONs')
+    parser.add_argument('output_directory', nargs='?',
+                        help='output file\'s location')
+    args = parser.parse_args()
+
+    project_root = os.path.abspath(args.project_root)
+    if build_tree.looks_like_mbedtls_root(project_root):
+        project_root = os.path.join(project_root, 'tf-psa-crypto')
+
+    crypto_core_directory = build_tree.crypto_core_directory(project_root)
+
+    output_directory = args.output_directory if args.output_directory is not None else \
+        crypto_core_directory
+
+    template_directory = args.template_dir if args.template_dir is not None else \
+        os.path.join(project_root,
+                     'scripts',
+                     'data_files',
+                     'driver_templates')
+    json_directory = args.json_dir if args.json_dir is not None else \
+        os.path.join(project_root,
+                     'scripts',
+                     'data_files',
+                     'driver_jsons')
+
+    try:
+        # Read and validate list of driver jsons from driverlist.json
+        merged_driver_json = read_driver_descriptions(project_root,
+                                                      json_directory,
+                                                      'driverlist.json')
+    except DriverReaderException as e:
+        trace_exception(e)
+        return 1
+    for template_filename in TEMPLATE_FILENAMES:
+        generate_driver_wrapper_file(template_directory, output_directory,
+                                     template_filename, merged_driver_json)
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())