Create protoc-gen-cppstream tool to auto-generate cpp proto field Ids.

It is very similiar to protoc-gen-javastream, which generates field Ids used
by ProtoOutputStream.cpp to dump protobuf data.

Bug: 65641021
Test: compile the streaming_proto:
      $ mmm -j frameworks/base/tools/streaming_proto/
      and run:
      $ PATH=$PATH:out/host/linux-x86/bin/protoc-gen-cppstream aprotoc
      --cppstream_out=tmp/
      frameworks/base/core/proto/android/service/procstats.proto
      frameworks/base/core/proto/android/util/common.proto

Change-Id: I68becc80b5166455455c5df28cd698601b4a1c1d

1 files changed, 273 insertions, 0 deletions

diff --git a/tools/streaming_proto/cpp/main.cpp b/tools/streaming_proto/cpp/main.cpp
new file mode 100644
index 000000000000..d4e1b7aede92
--- /dev/null
+++ b/tools/streaming_proto/cpp/main.cpp
@@ -0,0 +1,273 @@
+#include "Errors.h"
+#include "string_utils.h"
+
+#include "google/protobuf/compiler/plugin.pb.h"
+#include "google/protobuf/io/zero_copy_stream_impl.h"
+#include "google/protobuf/text_format.h"
+
+#include <iomanip>
+#include <iostream>
+#include <sstream>
+
+using namespace android::stream_proto;
+using namespace google::protobuf;
+using namespace google::protobuf::compiler;
+using namespace google::protobuf::io;
+using namespace std;
+
+/**
+ * Position of the field type in a (long long) fieldId.
+ */
+const uint64_t FIELD_TYPE_SHIFT = 32;
+
+//
+// FieldId flags for whether the field is single, repeated or packed.
+// TODO: packed is not supported yet.
+//
+const uint64_t FIELD_COUNT_SHIFT = 40;
+const uint64_t FIELD_COUNT_MASK = 0x0fULL << FIELD_COUNT_SHIFT;
+const uint64_t FIELD_COUNT_UNKNOWN = 0;
+const uint64_t FIELD_COUNT_SINGLE = 1ULL << FIELD_COUNT_SHIFT;
+const uint64_t FIELD_COUNT_REPEATED = 2ULL << FIELD_COUNT_SHIFT;
+const uint64_t FIELD_COUNT_PACKED = 4ULL << FIELD_COUNT_SHIFT;
+
+// Indent
+const string INDENT = "    ";
+
+/**
+ * See if this is the file for this request, and not one of the imported ones.
+ */
+static bool
+should_generate_for_file(const CodeGeneratorRequest& request, const string& file)
+{
+    const int N = request.file_to_generate_size();
+    for (int i=0; i<N; i++) {
+        if (request.file_to_generate(i) == file) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static string
+make_filename(const FileDescriptorProto& file_descriptor)
+{
+    return file_descriptor.name() + ".h";
+}
+
+static string
+get_proto_type(const FieldDescriptorProto& field)
+{
+    switch (field.type()) {
+        case FieldDescriptorProto::TYPE_DOUBLE:
+            return "double";
+        case FieldDescriptorProto::TYPE_FLOAT:
+            return "float";
+        case FieldDescriptorProto::TYPE_INT64:
+            return "int64";
+        case FieldDescriptorProto::TYPE_UINT64:
+            return "uint64";
+        case FieldDescriptorProto::TYPE_INT32:
+            return "int32";
+        case FieldDescriptorProto::TYPE_FIXED64:
+            return "fixed64";
+        case FieldDescriptorProto::TYPE_FIXED32:
+            return "fixed32";
+        case FieldDescriptorProto::TYPE_BOOL:
+            return "bool";
+        case FieldDescriptorProto::TYPE_STRING:
+            return "string";
+        case FieldDescriptorProto::TYPE_GROUP:
+            return "group<unsupported!>";
+        case FieldDescriptorProto::TYPE_MESSAGE:
+            return field.type_name();
+        case FieldDescriptorProto::TYPE_BYTES:
+            return "bytes";
+        case FieldDescriptorProto::TYPE_UINT32:
+            return "uint32";
+        case FieldDescriptorProto::TYPE_ENUM:
+            return field.type_name();
+        case FieldDescriptorProto::TYPE_SFIXED32:
+            return "sfixed32";
+        case FieldDescriptorProto::TYPE_SFIXED64:
+            return "sfixed64";
+        case FieldDescriptorProto::TYPE_SINT32:
+            return "sint32";
+        case FieldDescriptorProto::TYPE_SINT64:
+            return "sint64";
+        default:
+            // won't happen
+            return "void";
+    }
+}
+
+static void
+write_enum(stringstream& text, const EnumDescriptorProto& enu, const string& indent)
+{
+    const int N = enu.value_size();
+    text << indent << "// enum " << enu.name() << endl;
+    for (int i=0; i<N; i++) {
+        const EnumValueDescriptorProto& value = enu.value(i);
+        text << indent << "const uint32_t "
+                << make_constant_name(value.name())
+                << " = " << value.number() << ";" << endl;
+    }
+    text << endl;
+}
+
+static uint64_t
+get_field_id(const FieldDescriptorProto& field)
+{
+    // Number
+    uint64_t result = (uint64_t)field.number();
+
+    // Type
+    result |= (uint64_t)field.type() << FIELD_TYPE_SHIFT;
+
+    // Count
+    if (field.options().packed()) {
+        result |= FIELD_COUNT_PACKED;
+    } else if (field.label() == FieldDescriptorProto::LABEL_REPEATED) {
+        result |= FIELD_COUNT_REPEATED;
+    } else {
+        result |= FIELD_COUNT_SINGLE;
+    }
+
+    return result;
+}
+
+static void
+write_field(stringstream& text, const FieldDescriptorProto& field, const string& indent)
+{
+    string optional_comment = field.label() == FieldDescriptorProto::LABEL_OPTIONAL
+            ? "optional " : "";
+    string repeated_comment = field.label() == FieldDescriptorProto::LABEL_REPEATED
+            ? "repeated " : "";
+    string proto_type = get_proto_type(field);
+    string packed_comment = field.options().packed()
+            ? " [packed=true]" : "";
+    text << indent << "// " << optional_comment << repeated_comment << proto_type << ' '
+            << field.name() << " = " << field.number() << packed_comment << ';' << endl;
+
+    text << indent << "const uint64_t " << make_constant_name(field.name()) << " = 0x";
+
+    ios::fmtflags fmt(text.flags());
+    text << setfill('0') << setw(16) << hex << get_field_id(field);
+    text.flags(fmt);
+
+    text << "LL;" << endl;
+
+    text << endl;
+}
+
+static void
+write_message(stringstream& text, const DescriptorProto& message, const string& indent)
+{
+    int N;
+    const string indented = indent + INDENT;
+
+    text << indent << "// message " << message.name() << endl;
+    text << indent << "class " << message.name() << " {" << endl;
+    text << indent << "public:" << endl;
+
+    // Enums
+    N = message.enum_type_size();
+    for (int i=0; i<N; i++) {
+        write_enum(text, message.enum_type(i), indented);
+    }
+
+    // Nested classes
+    N = message.nested_type_size();
+    for (int i=0; i<N; i++) {
+        write_message(text, message.nested_type(i), indented);
+    }
+
+    // Fields
+    N = message.field_size();
+    for (int i=0; i<N; i++) {
+        write_field(text, message.field(i), indented);
+    }
+
+    text << indent << "};" << endl;
+    text << endl;
+}
+
+static void
+write_cpp_file(CodeGeneratorResponse* response, const FileDescriptorProto& file_descriptor)
+{
+    stringstream text;
+
+    text << "// Generated by protoc-gen-cppstream. DO NOT MODIFY." << endl;
+    text << "// source: " << file_descriptor.name() << endl << endl;
+
+    string header = "ANDROID_" + replace_string(file_descriptor.name(), '/', '_');
+    header = replace_string(header, '.', '_') + "_stream_h";
+    header = make_constant_name(header);
+
+    text << "#ifndef " << header << endl;
+    text << "#define " << header << endl;
+    text << endl;
+
+    vector<string> namespaces = split(file_descriptor.package(), '.');
+    for (vector<string>::iterator it = namespaces.begin(); it != namespaces.end(); it++) {
+        text << "namespace " << *it << " {" << endl;
+    }
+    text << endl;
+
+    size_t N;
+    N = file_descriptor.enum_type_size();
+    for (size_t i=0; i<N; i++) {
+        write_enum(text, file_descriptor.enum_type(i), "");
+    }
+
+    N = file_descriptor.message_type_size();
+    for (size_t i=0; i<N; i++) {
+        write_message(text, file_descriptor.message_type(i), "");
+    }
+
+    for (vector<string>::iterator it = namespaces.begin(); it != namespaces.end(); it++) {
+        text << "} // " << *it << endl;
+    }
+
+    text << endl;
+    text << "#endif // " << header << endl;
+
+    CodeGeneratorResponse::File* file_response = response->add_file();
+    file_response->set_name(make_filename(file_descriptor));
+    file_response->set_content(text.str());
+}
+
+int main(int argc, char const *argv[])
+{
+    (void)argc;
+    (void)argv;
+
+    GOOGLE_PROTOBUF_VERIFY_VERSION;
+
+    CodeGeneratorRequest request;
+    CodeGeneratorResponse response;
+
+    // Read the request
+    request.ParseFromIstream(&cin);
+
+    // Build the files we need.
+    const int N = request.proto_file_size();
+    for (int i=0; i<N; i++) {
+        const FileDescriptorProto& file_descriptor = request.proto_file(i);
+        if (should_generate_for_file(request, file_descriptor.name())) {
+            write_cpp_file(&response, file_descriptor);
+        }
+    }
+
+    // If we had errors, don't write the response. Print the errors and exit.
+    if (ERRORS.HasErrors()) {
+        ERRORS.Print();
+        return 1;
+    }
+
+    // If we didn't have errors, write the response and exit happily.
+    response.SerializeToOstream(&cout);
+
+    /* code */
+    return 0;
+}
\ No newline at end of file