#!/usr/bin/python3 # # Copyright (C) 2020 The Android Open Source Project # # Licensed 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. # import argparse import json import os.path import subprocess from collections import defaultdict from datetime import datetime from pyclibrary import CParser LICENSE_HEADER = """/* * Copyright (C) 2020 The Android Open Source Project * * Licensed 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. */ """ # Paths for output, relative to system/chre CHPP_PARSER_INCLUDE_PATH = "chpp/include/chpp/common" CHPP_PARSER_SOURCE_PATH = "chpp/common" def system_chre_abs_path(): """Gets the absolute path to the system/chre directory containing this script.""" script_dir = os.path.dirname(os.path.realpath(__file__)) # Assuming we're at system/chre/chpp/api_parser (i.e. up 2 to get to system/chre) chre_project_base_dir = os.path.normpath(script_dir + "/../..") return chre_project_base_dir class CodeGenerator: """Given an ApiParser object, generates a header file with structure definitions in CHPP format. """ def __init__(self, api, commit_hash): """ :param api: ApiParser object """ self.api = api self.json = api.json # Turn "chre_api/include/chre_api/chre/wwan.h" into "wwan" self.service_name = self.json['filename'].split('/')[-1].split('.')[0] self.capitalized_service_name = self.service_name[0].upper() + self.service_name[1:] self.commit_hash = commit_hash # ---------------------------------------------------------------------------------------------- # Header generation methods (plus some methods shared with encoder generation) # ---------------------------------------------------------------------------------------------- def _autogen_notice(self): out = [] out.append("// This file was automatically generated by {}\n".format( os.path.basename(__file__))) out.append("// Date: {} UTC\n".format(datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S'))) out.append("// Source: {} @ commit {}\n\n".format(self.json['filename'], self.commit_hash)) out.append("// DO NOT modify this file directly, as those changes will be lost the next\n") out.append("// time the script is executed\n\n") return out def _dump_to_file(self, output_filename, contents, dry_run, skip_clang_fomat): """Outputs contents to output_filename, or prints contents if dry_run is True""" if dry_run: print("---- {} ----".format(output_filename)) print(contents) print("---- end of {} ----\n".format(output_filename)) else: with open(output_filename, 'w') as f: f.write(contents) if not skip_clang_fomat: clang_format_path = os.path.normpath( "../../../../prebuilts/clang/host/linux-x86/clang-stable/bin/clang-format") args = [clang_format_path, '-i', output_filename] result = subprocess.run(args) result.check_returncode() def _is_array_type(self, type_info): # If this is an array type, declarators will be a tuple containing a list of # a single int element giving the size of the array return len(type_info.declarators) == 1 and isinstance(type_info.declarators[0], list) def _get_array_len(self, type_info): return type_info.declarators[0][0] def _get_chpp_type_from_chre(self, chre_type): """Given 'chreWwanCellInfo' returns 'struct ChppWwanCellInfo', etc.""" prefix = self._get_struct_or_union_prefix(chre_type) # First see if we have an explicit name override (e.g. for anonymous types) for annotation in self.api.annotations[chre_type]["."]: if annotation['annotation'] == "rename_type": return prefix + annotation['type_override'] # Otherwise, use the existing type name, just replace the "chre" prefix with "Chpp" if chre_type.startswith('chre'): return prefix + 'Chpp' + chre_type[4:] else: raise RuntimeError("Couldn't figure out new type name for {}".format(chre_type)) def _get_chre_type_with_prefix(self, chre_type): """Given 'chreWwanCellInfo' returns 'struct chreWwanCellInfo', etc.""" return self._get_struct_or_union_prefix(chre_type) + chre_type def _get_chpp_header_type_from_chre(self, chre_type): """Given 'chreWwanCellInfo' returns 'struct ChppWwanCellInfoWithHeader', etc.""" return self._get_chpp_type_from_chre(chre_type) + 'WithHeader' def _get_member_comment(self, member_info): for annotation in member_info['annotations']: if annotation['annotation'] == "fixed_value": return " // Input ignored; always set to {}".format(annotation['value']) elif annotation['annotation'] == "var_len_array": return " // References {} instances of {}".format( annotation['length_field'], self._get_member_type(member_info)) return "" def _get_member_type(self, member_info, underlying_vla_type=False): """Gets the CHPP type specification prefix for a struct/union member. :param member_info: a dict element from self.api.structs_and_unions[struct]['members'] :param underlying_vla_type: (used only for var-len array types) False to output 'struct ChppOffset', and True to output the type that ChppOffset references :return: type specification string that prefixes the field name, e.g. 'uint8_t' """ # 4 cases to handle: # 1) Annotation gives explicit type that we should use # 2) Annotation says this is a variable length array (so use ChppOffset if # underlying_vla_type is False) # 3) This is a struct/union type, so use the renamed (CHPP) type name # 4) Regular type, e.g. uint32_t, so just use the type spec as-is for annotation in member_info['annotations']: if annotation['annotation'] == "rewrite_type": return annotation['type_override'] elif not underlying_vla_type and annotation['annotation'] == "var_len_array": return "struct ChppOffset" if not underlying_vla_type and len(member_info['type'].declarators) > 0 and \ member_info['type'].declarators[0] == "*": # This case should either be handled by rewrite_type (e.g. to uint32_t as # opaque/ignored), or var_len_array raise RuntimeError("Pointer types require annotation\n{}".format( member_info)) if member_info['is_nested_type']: return self._get_chpp_type_from_chre(member_info['nested_type_name']) return member_info['type'].type_spec def _get_member_type_suffix(self, member_info): if self._is_array_type(member_info['type']): return "[{}]".format(self._get_array_len(member_info['type'])) return "" def _get_struct_or_union_prefix(self, chre_type): return 'struct ' if not self.api.structs_and_unions[chre_type]['is_union'] else 'union ' def _gen_header_includes(self): """Generates #include directives for use in _types.h""" out = ["#include \n#include \n#include \n\n"] includes = ["chpp/app.h", "chpp/macros.h", "chre_api/chre/version.h"] includes.extend(self.json['output_includes']) for incl in sorted(includes): out.append("#include \"{}\"\n".format(incl)) out.append("\n") return out def _gen_struct_or_union(self, name): """Generates the definition for a single struct/union type""" out = [] if not name.startswith('anon'): out.append("//! See {{@link {}}} for details\n".format(name)) out.append("{} {{\n".format(self._get_chpp_type_from_chre(name))) for member_info in self.api.structs_and_unions[name]['members']: out.append(" {} {}{};{}\n".format(self._get_member_type(member_info), member_info['name'], self._get_member_type_suffix(member_info), self._get_member_comment(member_info))) out.append("} CHPP_PACKED_ATTR;\n\n") return out def _gen_header_struct(self, chre_type): """Generates the definition for the type with header (WithHeader)""" out = [] out.append("//! CHPP app header plus {}\n".format( self._get_chpp_header_type_from_chre(chre_type))) out.append("{} {{\n".format(self._get_chpp_header_type_from_chre(chre_type))) out.append(" struct ChppAppHeader header;\n") out.append(" {} payload;\n".format(self._get_chpp_type_from_chre(chre_type))) out.append("} CHPP_PACKED_ATTR;\n\n") return out def _gen_structs_and_unions(self): """Generates definitions for all struct/union types required for the root structs.""" out = [] out.append("CHPP_PACKED_START\n\n") sorted_structs = self._sorted_structs(self.json['root_structs']) for type_name in sorted_structs: out.extend(self._gen_struct_or_union(type_name)) for chre_type in self.json['root_structs']: out.extend(self._gen_header_struct(chre_type)) out.append("CHPP_PACKED_END\n\n") return out def _sorted_structs(self, root_nodes): """Implements a topological sort on self.api.structs_and_unions. Elements are ordered by definition dependency, i.e. if A includes a field of type B, then B will appear before A in the returned list. :return: list of keys in self.api.structs_and_unions, sorted by dependency order """ result = [] visited = set() def sort_helper(collection, key): for dep in sorted(collection[key]['dependencies']): if dep not in visited: visited.add(dep) sort_helper(collection, dep) result.append(key) for node in sorted(root_nodes): sort_helper(self.api.structs_and_unions, node) return result # ---------------------------------------------------------------------------------------------- # Encoder function generation methods (CHRE --> CHPP) # ---------------------------------------------------------------------------------------------- def _get_chpp_member_sizeof_call(self, member_info): """Returns invocation used to determine the size of the provided member when encoded. Will be either sizeof() or a function call if the member contains a VLA :param member_info: a dict element from self.api.structs_and_unions[struct]['members'] :return: string """ type_name = None if member_info['is_nested_type']: chre_type = member_info['nested_type_name'] if self.api.structs_and_unions[chre_type]['has_vla_member']: return "{}(in->{})".format(self._get_chpp_sizeof_function_name(chre_type), member_info['name']) else: type_name = self._get_chpp_type_from_chre(chre_type) else: type_name = member_info['type'].type_spec return "sizeof({})".format(type_name) def _gen_chpp_sizeof_function(self, chre_type): """Generates a function to determine the encoded size of the CHRE struct, if necessary.""" out = [] # Note that this function *should* work with unions as well, but at the time of writing # it'll only be used with structs, so names, etc. are written with that in mind struct_info = self.api.structs_and_unions[chre_type] if not struct_info['has_vla_member']: # No codegen necessary, just sizeof on the CHPP structure name is sufficient return out core_type_name = self._strip_prefix_and_service_from_chre_struct_name(chre_type) parameter_name = core_type_name[0].lower() + core_type_name[1:] chpp_type_name = self._get_chpp_header_type_from_chre(chre_type) out.append("//! @return number of bytes required to represent the given\n" "//! {} along with the CHPP header as\n" "//! {}\n" .format(chre_type, chpp_type_name)) out.append("static size_t {}(\n const {}{} *{}) {{\n" .format(self._get_chpp_sizeof_function_name(chre_type), self._get_struct_or_union_prefix(chre_type), chre_type, parameter_name)) # sizeof(this struct) out.append(" size_t encodedSize = sizeof({});\n".format(chpp_type_name)) # Plus count * sizeof(type) for each var-len array included in this struct for member_info in self.api.structs_and_unions[chre_type]['members']: for annotation in member_info['annotations']: if annotation['annotation'] == "var_len_array": # If the VLA field itself contains a VLA, then we'd need to generate a for # loop to calculate the size of each element individually - I don't think we # have any of these in the CHRE API today, so leaving this functionality out. # Also note that to support that case we'd also want to recursively call this # function to generate sizeof functions for nested fields. if member_info['is_nested_type'] and \ self.api.structs_and_unions[member_info['nested_type_name']][ 'has_vla_member']: raise RuntimeError( "Nested variable-length arrays is not currently supported ({} " "in {})".format(member_info['name'], chre_type)) out.append(" encodedSize += {}->{} * sizeof({});\n".format( parameter_name, annotation['length_field'], self._get_member_type(member_info, True))) out.append(" return encodedSize;\n}\n\n") return out def _gen_chpp_sizeof_functions(self): """For each root struct, generate necessary functions to determine their encoded size.""" out = [] for struct in self.json['root_structs']: out.extend(self._gen_chpp_sizeof_function(struct)) return out def _gen_conversion_includes(self): """Generates #include directives for the conversion source file""" out = ["#include \"chpp/macros.h\"\n" "#include \"chpp/memory.h\"\n" "#include \"chpp/common/{}_types.h\"\n\n".format(self.service_name)] out.append("#include \n#include \n#include \n\n") return out def _get_chpp_sizeof_function_name(self, chre_struct): """Function name used to compute the encoded size of the given struct at runtime""" core_type_name = self._strip_prefix_and_service_from_chre_struct_name(chre_struct) return "chpp{}SizeOf{}FromChre".format(self.capitalized_service_name, core_type_name) def _get_encoding_function_name(self, chre_type): core_type_name = self._strip_prefix_and_service_from_chre_struct_name(chre_type) return "chpp{}Convert{}FromChre".format(self.capitalized_service_name, core_type_name) def _gen_encoding_function_signature(self, chre_type): out = [] out.append("void {}(\n".format(self._get_encoding_function_name(chre_type))) out.append(" const {}{} *in,\n".format( self._get_struct_or_union_prefix(chre_type), chre_type)) out.append(" {} *out".format(self._get_chpp_type_from_chre(chre_type))) if self.api.structs_and_unions[chre_type]['has_vla_member']: out.append(",\n") out.append(" uint8_t *payload,\n") out.append(" size_t payloadSize,\n") out.append(" uint16_t *vlaOffset") out.append(")") return out def _gen_vla_encoding(self, member_info, annotation): out = [] variable_name = member_info['name'] chpp_type = self._get_member_type(member_info, True) if member_info['is_nested_type']: out.append("\n {} *{} = ({} *) &payload[*vlaOffset];\n".format( chpp_type, variable_name, chpp_type)) out.append(" out->{}.length = in->{} * {};\n".format( member_info['name'], annotation['length_field'], self._get_chpp_member_sizeof_call(member_info))) out.append(" CHPP_ASSERT((size_t)(*vlaOffset + out->{}.length) <= payloadSize);\n".format( member_info['name'])) out.append(" if (out->{}.length > 0 &&\n" " *vlaOffset + out->{}.length <= payloadSize) {{\n".format( member_info['name'], member_info['name'])) if member_info['is_nested_type']: out.append(" for (size_t i = 0; i < in->{}; i++) {{\n".format( annotation['length_field'])) out.append(" {}".format( self._get_assignment_statement_for_field(member_info, in_vla_loop=True))) out.append(" }\n") else: out.append("memcpy(&payload[*vlaOffset], in->{}, in->{} * sizeof({}));\n".format( member_info['name'], annotation['length_field'], chpp_type)) out.append(" out->{}.offset = *vlaOffset;\n".format(member_info['name'])) out.append(" *vlaOffset += out->{}.length;\n".format(member_info['name'])) out.append(" } else {\n") out.append(" out->{}.offset = 0;\n".format(member_info['name'])) out.append(" }\n"); return out # ---------------------------------------------------------------------------------------------- # Encoder / decoder function generation methods (CHRE <--> CHPP) # ---------------------------------------------------------------------------------------------- def _get_assignment_statement_for_field(self, member_info, in_vla_loop=False, containing_field_name=None, decode_mode=False): """Returns a statement to assign the provided member :param member_info: :param in_vla_loop: True if we're currently inside a loop and should append [i] :param containing_field_name: Additional member name to use to access the target field, or None; for example the normal case is "out->field = in->field", but if we're generating assignments in the parent conversion function (e.g. as used for union variants), we need to do "out->nested_field.field = in->nested_field.field" :param decode_mode: True converts from CHPP to CHRE. False from CHRE to CHPP :return: assignment statement as a string """ array_index = "[i]" if in_vla_loop else "" output_accessor = "" if in_vla_loop else "out->" containing_field = containing_field_name + "." if containing_field_name is not None else "" output_variable = "{}{}{}{}".format(output_accessor, containing_field, member_info['name'], array_index) input_variable = "in->{}{}{}".format(containing_field, member_info['name'], array_index) if decode_mode and in_vla_loop: output_variable = "{}Out{}".format(member_info['name'], array_index) input_variable = "{}In{}".format(member_info['name'], array_index) if member_info['is_nested_type']: chre_type = member_info['nested_type_name'] has_vla_member = self.api.structs_and_unions[chre_type]['has_vla_member'] if decode_mode: # Use decoding function vla_params = ", inSize" if has_vla_member else "" out = "if (!{}(&{}, &{}{})) {{\n".format( self._get_decoding_function_name(chre_type), input_variable, output_variable, vla_params) if has_vla_member: out += " CHPP_FREE_AND_NULLIFY({}Out);\n".format(member_info['name']) out += " return false;\n" out += "}\n" return out else: # Use encoding function vla_params = ", payload, payloadSize, vlaOffset" if has_vla_member else "" return "{}(&{}, &{}{});\n".format( self._get_encoding_function_name(chre_type), input_variable, output_variable, vla_params) elif self._is_array_type(member_info['type']): # Array of primitive type (e.g. uint32_t[8]) - use memcpy return "memcpy({}, {}, sizeof({}));\n".format(output_variable, input_variable, output_variable) else: # Regular assignment return "{} = {};\n".format(output_variable, input_variable) def _gen_union_variant_conversion_code(self, member_info, annotation, decode_mode): """Generates a switch statement to encode the "active"/"used" field within a union. Handles cases where a union has multiple types, but there's another peer/adjacent field which tells you which field in the union is to be used. Outputs code like this: switch (in->{discriminator field}) { case {first discriminator value associated with a fields}: {conversion code for the field associated with this discriminator value} ... :param chre_type: CHRE type of the union :param annotation: Reference to JSON annotation data with the discriminator mapping data :param decode_mode: False encodes from CHRE to CHPP. True decodes from CHPP to CHRE :return: list of strings """ out = [] chre_type = member_info['nested_type_name'] struct_info = self.api.structs_and_unions[chre_type] # Start off by zeroing out the union field so any padding is set to a consistent value out.append(" memset(&out->{}, 0, sizeof(out->{}));\n".format(member_info['name'], member_info['name'])) # Next, generate the switch statement that will copy over the proper values out.append(" switch (in->{}) {{\n".format(annotation['discriminator'])) for value, field_name in annotation['mapping']: out.append(" case {}:\n".format(value)) found = False for nested_member_info in struct_info['members']: if nested_member_info['name'] == field_name: out.append(" {}".format( self._get_assignment_statement_for_field( nested_member_info, containing_field_name=member_info['name'], decode_mode=decode_mode))) found = True break if not found: raise RuntimeError("Invalid mapping - couldn't find target field {} in struct {}" .format(field_name, chre_type)) out.append(" break;\n") out.append(" default:\n" " CHPP_ASSERT(false);\n" " }\n") return out def _gen_conversion_function(self, chre_type, already_generated, decode_mode): out = [] struct_info = self.api.structs_and_unions[chre_type] for dependency in sorted(struct_info['dependencies']): if dependency not in already_generated: out.extend( self._gen_conversion_function(dependency, already_generated, decode_mode)) # Skip if we've already generated code for this type, or if it's a union (in which case we # handle the assignment in the parent structure to enable support for discrimination of # which field in the union to use) if chre_type in already_generated or struct_info['is_union']: return out already_generated.add(chre_type) out.append("static ") if decode_mode: out.extend(self._gen_decoding_function_signature(chre_type)) else: out.extend(self._gen_encoding_function_signature(chre_type)) out.append(" {\n") for member_info in self.api.structs_and_unions[chre_type]['members']: generated_by_annotation = False for annotation in member_info['annotations']: if annotation['annotation'] == "fixed_value": if self._is_array_type(member_info['type']): out.append(" memset(&out->{}, {}, sizeof(out->{}));\n".format( member_info['name'], annotation['value'], member_info['name'])) else: out.append(" out->{} = {};\n".format(member_info['name'], annotation['value'])) generated_by_annotation = True break elif annotation['annotation'] == "enum": # TODO: generate range verification code? pass elif annotation['annotation'] == "var_len_array": if decode_mode: out.extend(self._gen_vla_decoding(member_info, annotation)) else: out.extend(self._gen_vla_encoding(member_info, annotation)) generated_by_annotation = True break elif annotation['annotation'] == "union_variant": out.extend(self._gen_union_variant_conversion_code( member_info, annotation, decode_mode)) generated_by_annotation = True break if not generated_by_annotation: out.append(" {}".format( self._get_assignment_statement_for_field(member_info, decode_mode=decode_mode))) if decode_mode: out.append("\n return true;\n") out.append("}\n\n") return out def _gen_conversion_functions(self, decode_mode): out = [] already_generated = set() for struct in self.json['root_structs']: out.extend(self._gen_conversion_function(struct, already_generated, decode_mode)) return out def _strip_prefix_and_service_from_chre_struct_name(self, struct): """Strip 'chre' and service prefix, e.g. 'chreWwanCellResultInfo' -> 'CellResultInfo'""" chre_stripped = struct[4:] upcased_service_name = self.service_name[0].upper() + self.service_name[1:] if not struct.startswith('chre') or not chre_stripped.startswith(upcased_service_name): # If this happens, we need to update the script to handle it. Right we assume struct # naming follows the pattern "chre" raise RuntimeError("Unexpected structure name {}".format(struct)) return chre_stripped[len(self.service_name):] # ---------------------------------------------------------------------------------------------- # Memory allocation generation methods # ---------------------------------------------------------------------------------------------- def _get_chpp_sizeof_call(self, chre_type): """Returns invocation used to determine the size of the provided CHRE struct (with the CHPP app header) after encoding. Like _get_chpp_member_sizeof_call(), except for a top-level type assigned to the variable "in" rather than a member within a structure (e.g. a VLA field) :param chre_type: CHRE type name :return: string """ if self.api.structs_and_unions[chre_type]['has_vla_member']: return "{}(in)".format(self._get_chpp_sizeof_function_name(chre_type)) else: return "sizeof({})".format(self._get_chpp_header_type_from_chre(chre_type)) def _get_encode_allocation_function_name(self, chre_type): core_type_name = self._strip_prefix_and_service_from_chre_struct_name(chre_type) return "chpp{}{}FromChre".format(self.capitalized_service_name, core_type_name) def _gen_encode_allocation_function_signature(self, chre_type, gen_docs=False): out = [] if gen_docs: out.append("/**\n" " * Converts from given CHRE structure to serialized CHPP type.\n" " *\n" " * @param in Fully-formed CHRE structure.\n" " * @param out Upon success, will point to a buffer allocated with " "chppMalloc().\n" " * It is the responsibility of the caller to set the values of the CHPP " "app layer header, and to free the buffer when it is no longer needed via " "chppFree() or CHPP_FREE_AND_NULLIFY().\n" " * @param outSize Upon success, will be set to the size of the output " "buffer, in bytes.\n" " *\n" " * @return true on success, false if memory allocation failed.\n" " */\n") out.append("bool {}(\n".format(self._get_encode_allocation_function_name(chre_type))) out.append(" const {}{} *in,\n".format( self._get_struct_or_union_prefix(chre_type), chre_type)) out.append(" {} **out,\n".format(self._get_chpp_header_type_from_chre(chre_type))) out.append(" size_t *outSize)") return out def _gen_encode_allocation_function(self, chre_type): out = [] out.extend(self._gen_encode_allocation_function_signature(chre_type)) out.append(" {\n") out.append(" CHPP_NOT_NULL(out);\n") out.append(" CHPP_NOT_NULL(outSize);\n\n") out.append(" size_t payloadSize = {};\n".format( self._get_chpp_sizeof_call(chre_type))) out.append(" *out = chppMalloc(payloadSize);\n") out.append(" if (*out != NULL) {\n") struct_info = self.api.structs_and_unions[chre_type] if struct_info['has_vla_member']: out.append(" uint8_t *payload = (uint8_t *) &(*out)->payload;\n") out.append(" uint16_t vlaOffset = sizeof({});\n".format( self._get_chpp_type_from_chre(chre_type))) out.append(" {}(in, &(*out)->payload".format( self._get_encoding_function_name(chre_type))) if struct_info['has_vla_member']: out.append(", payload, payloadSize, &vlaOffset") out.append(");\n") out.append(" *outSize = payloadSize;\n") out.append(" return true;\n") out.append(" }\n") out.append(" return false;\n}\n\n") return out def _gen_encode_allocation_functions(self): out = [] for chre_type in self.json['root_structs']: out.extend(self._gen_encode_allocation_function(chre_type)) return out def _gen_encode_allocation_function_signatures(self): out = [] for chre_type in self.json['root_structs']: out.extend(self._gen_encode_allocation_function_signature(chre_type, True)) out.append(";\n\n") return out # ---------------------------------------------------------------------------------------------- # Decoder function generation methods (CHPP --> CHRE) # ---------------------------------------------------------------------------------------------- def _get_decoding_function_name(self, chre_type): core_type_name = self._strip_prefix_and_service_from_chre_struct_name(chre_type) return "chpp{}Convert{}ToChre".format(self.capitalized_service_name, core_type_name) def _gen_decoding_function_signature(self, chre_type): out = [] out.append("bool {}(\n".format(self._get_decoding_function_name(chre_type))) out.append(" const {} *in,\n".format(self._get_chpp_type_from_chre(chre_type))) out.append(" {} *out".format(self._get_chre_type_with_prefix(chre_type))) if self.api.structs_and_unions[chre_type]['has_vla_member']: out.append(",\n") out.append(" size_t inSize") out.append(")") return out def _gen_vla_decoding(self, member_info, annotation): out = [] variable_name = member_info['name'] chpp_type = self._get_member_type(member_info, True) if member_info['is_nested_type']: chre_type = self._get_chre_type_with_prefix(member_info['nested_type_name']) else: chre_type = chpp_type out.append("\n") out.append(" if (in->{}.length == 0) {{\n".format(variable_name)) out.append(" out->{} = NULL;\n".format(variable_name)) out.append(" }\n") out.append(" else {\n") out.append(" if (in->{}.offset + in->{}.length > inSize ||\n".format( variable_name, variable_name)) out.append(" in->{}.length != in->{} * sizeof({})) {{\n".format( variable_name, annotation['length_field'], chpp_type)) out.append(" return false;\n") out.append(" }\n\n") if member_info['is_nested_type']: out.append(" const {} *{}In =\n".format(chpp_type, variable_name)) out.append(" (const {} *) &((const uint8_t *)in)[in->{}.offset];\n\n".format( chpp_type, variable_name)) out.append(" {} *{}Out = chppMalloc(in->{} * sizeof({}));\n".format( chre_type, variable_name, annotation['length_field'], chre_type)) out.append(" if ({}Out == NULL) {{\n".format(variable_name)) out.append(" return false;\n") out.append(" }\n\n") if member_info['is_nested_type']: out.append(" for (size_t i = 0; i < in->{}; i++) {{\n".format( annotation['length_field'], variable_name)) out.append(" {}".format(self._get_assignment_statement_for_field( member_info, in_vla_loop=True, decode_mode=True))) out.append(" }\n") else: out.append(" memcpy({}Out, &((const uint8_t *)in)[in->{}.offset],\n".format( variable_name, variable_name)) out.append(" in->{} * sizeof({}));\n".format( annotation['length_field'], chre_type)) out.append(" out->{} = {}Out;\n".format(variable_name, variable_name)) out.append(" }\n\n") return out def _get_decode_allocation_function_name(self, chre_type): core_type_name = self._strip_prefix_and_service_from_chre_struct_name(chre_type) return "chpp{}{}ToChre".format(self.capitalized_service_name, core_type_name) def _gen_decode_allocation_function_signature(self, chre_type, gen_docs=False): out = [] if gen_docs: out.append("/**\n" " * Converts from serialized CHPP structure to a CHRE type.\n" " *\n" " * @param in Fully-formed CHPP structure.\n" " * @param in Size of the CHPP structure in bytes.\n" " *\n" " * @return If successful, a pointer to a CHRE structure allocated with " "chppMalloc(). If unsuccessful, null.\n" " * It is the responsibility of the caller to free the buffer when it is no " "longer needed via chppFree() or CHPP_FREE_AND_NULLIFY().\n" " */\n") out.append("{} *{}(\n".format( self._get_chre_type_with_prefix(chre_type), self._get_decode_allocation_function_name(chre_type))) out.append(" const {} *in,\n".format(self._get_chpp_type_from_chre(chre_type))) out.append(" size_t inSize)") return out def _gen_decode_allocation_function(self, chre_type): out = [] out.extend(self._gen_decode_allocation_function_signature(chre_type)) out.append(" {\n") out.append(" {} *out = NULL;\n\n".format( self._get_chre_type_with_prefix(chre_type))) out.append(" if (inSize >= sizeof({})) {{\n".format( self._get_chpp_type_from_chre(chre_type))) out.append(" out = chppMalloc(sizeof({}));\n".format( self._get_chre_type_with_prefix(chre_type))) out.append(" if (out != NULL) {\n") struct_info = self.api.structs_and_unions[chre_type] out.append(" if (!{}(in, out".format(self._get_decoding_function_name(chre_type))) if struct_info['has_vla_member']: out.append(", inSize") out.append(")) {") out.append(" CHPP_FREE_AND_NULLIFY(out);\n") out.append(" }\n") out.append(" }\n") out.append(" }\n\n") out.append(" return out;\n") out.append("}\n") return out def _gen_decode_allocation_functions(self): out = [] for chre_type in self.json['root_structs']: out.extend(self._gen_decode_allocation_function(chre_type)) return out def _gen_decode_allocation_function_signatures(self): out = [] for chre_type in self.json['root_structs']: out.extend(self._gen_decode_allocation_function_signature(chre_type, True)) out.append(";\n\n") return out # ---------------------------------------------------------------------------------------------- # Public methods # ---------------------------------------------------------------------------------------------- def generate_header_file(self, dry_run=False, skip_clang_format=False): """Creates a C header file for this API and writes it to the file indicated in the JSON.""" filename = self.service_name + "_types.h" if not dry_run: print("Generating {} ... ".format(filename), end='', flush=True) output_file = os.path.join(system_chre_abs_path(), CHPP_PARSER_INCLUDE_PATH, filename) header = self.generate_header_string() self._dump_to_file(output_file, header, dry_run, skip_clang_format) if not dry_run: print("done") def generate_header_string(self): """Returns a C header with structure definitions for this API.""" # To defer concatenation (speed things up), build the file as a list of strings then only # concatenate once at the end out = [LICENSE_HEADER] header_guard = "CHPP_{}_TYPES_H_".format(self.service_name.upper()) out.append("#ifndef {}\n#define {}\n\n".format(header_guard, header_guard)) out.extend(self._autogen_notice()) out.extend(self._gen_header_includes()) out.append("#ifdef __cplusplus\nextern \"C\" {\n#endif\n\n") out.extend(self._gen_structs_and_unions()) out.append("\n// Encoding functions (CHRE --> CHPP)\n\n") out.extend(self._gen_encode_allocation_function_signatures()) out.append("\n// Decoding functions (CHPP --> CHRE)\n\n") out.extend(self._gen_decode_allocation_function_signatures()) out.append("#ifdef __cplusplus\n}\n#endif\n\n") out.append("#endif // {}\n".format(header_guard)) return ''.join(out) def generate_conversion_file(self, dry_run=False, skip_clang_format=False): """Generates a .c file with functions for encoding CHRE structs into CHPP and vice versa.""" filename = self.service_name + "_convert.c" if not dry_run: print("Generating {} ... ".format(filename), end='', flush=True) contents = self.generate_conversion_string() output_file = os.path.join(system_chre_abs_path(), CHPP_PARSER_SOURCE_PATH, filename) self._dump_to_file(output_file, contents, dry_run, skip_clang_format) if not dry_run: print("done") def generate_conversion_string(self): """Returns C code for encoding CHRE structs into CHPP and vice versa.""" out = [LICENSE_HEADER, "\n"] out.extend(self._autogen_notice()) out.extend(self._gen_conversion_includes()) out.append("\n// Encoding (CHRE --> CHPP) size functions\n\n") out.extend(self._gen_chpp_sizeof_functions()) out.append("\n// Encoding (CHRE --> CHPP) conversion functions\n\n") out.extend(self._gen_conversion_functions(False)) out.append("\n// Encoding (CHRE --> CHPP) top-level functions\n\n") out.extend(self._gen_encode_allocation_functions()) out.append("\n// Decoding (CHPP --> CHRE) conversion functions\n\n") out.extend(self._gen_conversion_functions(True)) out.append("\n// Decoding (CHPP --> CHRE) top-level functions\n\n") out.extend(self._gen_decode_allocation_functions()) return ''.join(out) class ApiParser: """Given a file-specific set of annotations (extracted from JSON annotations file), parses a single API header file into data structures suitable for use with code generation. """ def __init__(self, json_obj): """Initialize and parse the API file described in the provided JSON-derived object. :param json_obj: Extracted file-specific annotations from JSON """ self.json = json_obj self.structs_and_unions = {} self._parse_annotations() self._parse_api() def _parse_annotations(self): # Convert annotations list to a more usable data structure: dict keyed by structure name, # containing a dict keyed by field name, containing a list of annotations (as they # appear in the JSON). In other words, we can easily get all of the annotations for the # "version" field in "chreWwanCellInfoResult" via # annotations['chreWwanCellInfoResult']['version']. This is also a defaultdict, so it's safe # to access if there are no annotations for this structure + field; it'll just give you # an empty list in that case. self.annotations = defaultdict(lambda: defaultdict(list)) for struct_info in self.json['struct_info']: for annotation in struct_info['annotations']: self.annotations[struct_info['name']][annotation['field']].append(annotation) def _files_to_parse(self): """Returns a list of files to supply as input to CParser""" # Input paths for CParser are stored in JSON relative to /system/chre # Reformulate these to absolute paths, and add in some default includes that we always # supply chre_project_base_dir = system_chre_abs_path() default_includes = ["chpp/api_parser/parser_defines.h", "chre_api/include/chre_api/chre/version.h"] files = default_includes + self.json['includes'] + [self.json['filename']] return [os.path.join(chre_project_base_dir, file) for file in files] def _parse_structs_and_unions(self): # Starting with the root structures (i.e. those that will appear at the top-level in one # or more CHPP messages), build a data structure containing all of the information we'll # need to emit the CHPP structure definition and conversion code. structs_and_unions_to_parse = self.json['root_structs'].copy() while len(structs_and_unions_to_parse) > 0: type_name = structs_and_unions_to_parse.pop() if type_name in self.structs_and_unions: continue entry = { 'appears_in': set(), # Other types this type is nested within 'dependencies': set(), # Types that are nested in this type 'has_vla_member': False, # True if this type or any dependency has a VLA member 'members': [], # Info about each member of this type } if type_name in self.parser.defs['structs']: defs = self.parser.defs['structs'][type_name] entry['is_union'] = False elif type_name in self.parser.defs['unions']: defs = self.parser.defs['unions'][type_name] entry['is_union'] = True else: raise RuntimeError("Couldn't find {} in parsed structs/unions".format(type_name)) for member_name, member_type, _ in defs['members']: member_info = { 'name': member_name, 'type': member_type, 'annotations': self.annotations[type_name][member_name], 'is_nested_type': False, } if member_type.type_spec.startswith('struct ') or \ member_type.type_spec.startswith('union '): member_info['is_nested_type'] = True member_type_name = member_type.type_spec.split(' ')[1] member_info['nested_type_name'] = member_type_name entry['dependencies'].add(member_type_name) structs_and_unions_to_parse.append(member_type_name) entry['members'].append(member_info) # Flip a flag if this structure has at least one variable-length array member, which # means that the encoded size can only be computed at runtime if not entry['has_vla_member']: for annotation in self.annotations[type_name][member_name]: if annotation['annotation'] == "var_len_array": entry['has_vla_member'] = True self.structs_and_unions[type_name] = entry # Build reverse linkage of dependency chain (i.e. lookup between a type and the other types # it appears in) for type_name, type_info in self.structs_and_unions.items(): for dependency in type_info['dependencies']: self.structs_and_unions[dependency]['appears_in'].add(type_name) # Bubble up "has_vla_member" to types each type it appears in, i.e. if this flag is set to # True on a leaf node, then all its ancestors should also have the flag set to True for type_name, type_info in self.structs_and_unions.items(): if type_info['has_vla_member']: types_to_mark = list(type_info['appears_in']) while len(types_to_mark) > 0: type_to_mark = types_to_mark.pop() self.structs_and_unions[type_to_mark]['has_vla_member'] = True types_to_mark.extend(list(self.structs_and_unions[type_to_mark]['appears_in'])) def _parse_api(self): file_to_parse = self._files_to_parse() self.parser = CParser(file_to_parse, cache='parser_cache') self._parse_structs_and_unions() def run(args): with open('chre_api_annotations.json') as f: js = json.load(f) commit_hash = subprocess.getoutput("git describe --always --long --dirty --exclude '*'") for file in js: if args.file_filter: matched = False for matcher in args.file_filter: if matcher in file['filename']: matched = True break if not matched: print("Skipping {} - doesn't match filter(s) {}".format(file['filename'], args.file_filter)) continue print("Parsing {} ... ".format(file['filename']), end='', flush=True) api_parser = ApiParser(file) code_gen = CodeGenerator(api_parser, commit_hash) print("done") code_gen.generate_header_file(args.dry_run, args.skip_clang_format) code_gen.generate_conversion_file(args.dry_run, args.skip_clang_format) if __name__ == "__main__": parser = argparse.ArgumentParser(description='Generate CHPP serialization code from CHRE APIs.') parser.add_argument('-n', dest='dry_run', action='store_true', help='Print the output instead of writing to a file') parser.add_argument('--skip-clang-format', dest='skip_clang_format', action='store_true', help='Skip running clang-format on the output files (doesn\'t apply to dry ' 'runs)') parser.add_argument('file_filter', nargs='*', help='Filters the input files (filename field in the JSON) to generate a ' 'subset of the typical output, e.g. "wifi" to just generate conversion' ' routines for wifi.h') args = parser.parse_args() run(args)