Merge "PDL: Rust code handles multiple constraints" (d1a2be60) · Commits · e / os / android_packages_modules_Bluetooth

system/gd/packet/parser/Android.bp

+1 −1

Original line number	Diff line number	Diff line
		@@ -33,10 +33,10 @@ cc_binary_host {
		"fields/variable_length_struct_field.cc",
		"checksum_def.cc",
		"custom_field_def.cc",
		"packet_dependency.cc",
		"enum_def.cc",
		"enum_gen.cc",
		"packet_def.cc",
		"packet_dependency.cc",
		"parent_def.cc",
		"struct_def.cc",
		"struct_parser_generator.cc",

system/gd/packet/parser/BUILD.gn

+1 −0

Original line number	Diff line number	Diff line
		@@ -62,6 +62,7 @@ executable("bluetooth_packetgen") {
		"gen_rust.cc",
		"main.cc",
		"packet_def.cc",
		"packet_dependency.cc",
		"parent_def.cc",
		"struct_def.cc",
		"struct_parser_generator.cc",

system/gd/packet/parser/packet_def.cc

+110 −36

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@
		#include <set>

		#include "fields/all_fields.h"
		#include "packet_dependency.h"
		#include "util.h"

		PacketDef::PacketDef(std::string name, FieldList fields) : ParentDef(name, fields, nullptr) {}
		@@ -883,8 +884,9 @@ void PacketDef::GenRustStructFieldNames(std::ostream& s) const {
		}

		void PacketDef::GenRustStructImpls(std::ostream& s) const {
		s << "impl " << name_ << "Data {";
		auto packet_dep = PacketDependency(GetRootDef());

		s << "impl " << name_ << "Data {";
		// conforms function
		s << "fn conforms(bytes: &[u8]) -> bool {";
		GenRustConformanceCheck(s);
		@@ -904,15 +906,15 @@ void PacketDef::GenRustStructImpls(std::ostream& s) const {
		s << " true";
		s << "}";

		// parse function
		if (parent_constraints_.empty() && children_.size() > 1 && parent_ != nullptr) {
		auto constraint = FindConstraintField();
		auto constraint_field = GetParamList().GetField(constraint);
		auto parse_params = packet_dep.GetDependencies(name_);
		s << "fn parse(bytes: &[u8]";
		for (auto field_name : parse_params) {
		auto constraint_field = GetParamList().GetField(field_name);
		auto constraint_type = constraint_field->GetRustDataType();
		s << "fn parse(bytes: &[u8], " << constraint << ": " << constraint_type << ") -> Result<Self> {";
		} else {
		s << "fn parse(bytes: &[u8]) -> Result<Self> {";
		s << ", " << field_name << ": " << constraint_type;
		}
		s << ") -> Result<Self> {";

		fields = fields_.GetFieldsWithoutTypes({
		BodyField::kFieldType,
		});
		@@ -940,51 +942,123 @@ void PacketDef::GenRustStructImpls(std::ostream& s) const {
		payload_offset = GetOffsetForField(payload_field[0]->GetName(), false);
		}

		auto constraint_name = FindConstraintField();
		auto constrained_descendants = FindDescendantsWithConstraint(constraint_name);

		if (children_.size() > 1) {
		s << "let child = match " << constraint_name << " {";
		auto match_on_variables = packet_dep.GetChildrenDependencies(name_);
		// If match_on_variables is empty, this means there are multiple abstract packets which will
		// specialize to a child down the packet tree.
		// In this case match variables will be the union of parent fields and parse params of children.
		if (match_on_variables.empty()) {
		for (auto& field : fields_) {
		if (std::any_of(children_.begin(), children_.end(), [&](auto child) {
		auto pass_me = packet_dep.GetDependencies(child->name_);
		return std::find(pass_me.begin(), pass_me.end(), field->GetName()) != pass_me.end();
		})) {
		match_on_variables.push_back(field->GetName());
		}
		}
		}

		for (const auto& desc : constrained_descendants) {
		auto desc_path = FindPathToDescendant(desc.first->name_);
		std::reverse(desc_path.begin(), desc_path.end());
		auto constraint_field = GetParamList().GetField(constraint_name);
		s << "let child = match (";

		for (auto var : match_on_variables) {
		if (var == match_on_variables[match_on_variables.size() - 1]) {
		s << var;
		} else {
		s << var << ", ";
		}
		}
		s << ") {";

		auto get_match_val = [&](
		std::string& match_var,
		std::variant<int64_t,
		std::string> constraint) -> std::string {
		auto constraint_field = GetParamList().GetField(match_var);
		auto constraint_type = constraint_field->GetFieldType();

		if (constraint_type == EnumField::kFieldType) {
		auto type = std::get<std::string>(desc.second);
		auto type = std::get<std::string>(constraint);
		auto variant_name = type.substr(type.find("::") + 2, type.length());
		auto enum_type = type.substr(0, type.find("::"));
		auto enum_variant = enum_type + "::"
		+ util::UnderscoreToCamelCase(util::ToLowerCase(variant_name));
		s << enum_variant;
		s << " if " << desc_path[0]->name_ << "Data::conforms(&bytes[..])";
		return enum_type + "::" + util::UnderscoreToCamelCase(util::ToLowerCase(variant_name));
		}
		if (constraint_type == ScalarField::kFieldType) {
		return std::to_string(std::get<int64_t>(constraint));
		}
		return "_";
		};

		for (auto& child : children_) {
		s << "(";
		for (auto var : match_on_variables) {
		std::string match_val = "_";

		if (child->parent_constraints_.find(var) != child->parent_constraints_.end()) {
		match_val = get_match_val(var, child->parent_constraints_[var]);
		} else {
		auto dcs = child->FindDescendantsWithConstraint(var);
		std::vector<std::string> all_match_vals;
		for (auto& desc : dcs) {
		all_match_vals.push_back(get_match_val(var, desc.second));
		}
		match_val = "";
		for (std::size_t i = 0; i < all_match_vals.size(); ++i) {
		match_val += all_match_vals[i];
		if (i != all_match_vals.size() - 1) {
		match_val += " \| ";
		}
		}
		match_val = (match_val == "") ? "_" : match_val;
		}

		if (var == match_on_variables[match_on_variables.size() - 1]) {
		s << match_val << ")";
		} else {
		s << match_val << ", ";
		}
		}
		s << " if " << child->name_ << "Data::conforms(&bytes[..])";
		s << " => {";
		s << name_ << "DataChild::";
		s << desc_path[0]->name_ << "(Arc::new(";
		if (desc_path[0]->parent_constraints_.empty()) {
		s << desc_path[0]->name_ << "Data::parse(&bytes[..]";
		s << ", " << enum_variant << ")?))";
		s << child->name_ << "(Arc::new(";

		auto child_parse_params = packet_dep.GetDependencies(child->name_);
		if (child_parse_params.size() == 0) {
		s << child->name_ << "Data::parse(&bytes[..]";
		} else {
		s << desc_path[0]->name_ << "Data::parse(&bytes[..])?))";
		s << child->name_ << "Data::parse(&bytes[..], ";
		}

		for (auto var : child_parse_params) {
		if (var == child_parse_params[child_parse_params.size() - 1]) {
		s << var;
		} else {
		s << var << ", ";
		}
		} else if (constraint_type == ScalarField::kFieldType) {
		s << std::get<int64_t>(desc.second) << " => {";
		s << "unimplemented!();";
		}
		s << ")?))";
		s << "}\n";
		}

		if (!constrained_descendants.empty()) {
		s << "v => return Err(Error::ConstraintOutOfBounds{field: \"" << constraint_name
		<< "\".to_string(), value: v as u64}),";
		s << "(";
		for (int i = 1; i <= match_on_variables.size(); i++) {
		if (i == match_on_variables.size()) {
		s << "_";
		} else {
		s << "_, ";
		}

		}
		s << ")";
		s << " => return Err(Error::InvalidPacketError),";
		s << "};\n";
		} else if (children_.size() == 1) {
		auto child = children_.at(0);
		s << "let child = match " << child->name_ << "Data::parse(&bytes[..]) {";
		auto params = packet_dep.GetDependencies(child->name_);
		s << "let child = match " << child->name_ << "Data::parse(&bytes[..]";
		for (auto field_name : params) {
		s << ", " << field_name;
		}
		s << ") {";
		s << " Ok(c) if " << child->name_ << "Data::conforms(&bytes[..]) => {";
		s << name_ << "DataChild::" << child->name_ << "(Arc::new(c))";
		s << " },";