Meaning of RawStringFormats and Delimeters 'pb' in clang format

Question

I cannot understand how does the following affect the formatting behavior in the clang format file:

RawStringFormats: 
  - Delimiters:       [pb]
    Language:        TextProto
    BasedOnStyle:    google

Are these settings correct for a c++ project? (e.g. shouldn't the language be cpp?)

What does it mean 'pb' for Delimeters and how is it different from 'cc' and 'cpp'?

I tried to look for information inside clang documentations but it just adds to my confusion.

Answer 1

[pb] as the delimiter there stands for ProtocolBuffers or Protobuf in short. The RawStringFormat formatting option is specifically for acting as a hint to detect and format code fragments that appear as raw strings within the file (for supported languages); It uses the Delimiters or the EnclosingFunctions to detect and reformat them using the specified formatting style.

It could be useful even in a C++ project, if you want the formatting to be applied to raw strings in the file. For example, often C++ projects that uses protobuf input and output has test code that might look like:

InputProto ConstructInput() {
  InputProto input;
  Input *in = input.mutable_input();
  in->set_id(10);
  in->set_name("Test");
  return in;
}
TEST(TestFoo, ComputesOut) {
OutputProto out;
out.set_result(200);

EXPECT_THAT(
    GetOutput(ConstructInput()),
    EqualsProto(outcome));
}

Protobuf allows you to write the same in a more human readable fashion using text format like so:

TEST(TestFoo, ComputesOut) {
EXPECT_THAT(
    GetOutput(PARSE_TEXT_PROTO(R"pb(
        input {
            id: 10
            name: "Test"
        }
      )")),
    EqualsProto(PARSE_TEXT_PROTO(R"pb(
        result: 200
      )"))
    );
}

And your formatting options would detect the text string within the pb delimiter as protobuf code and reformat it using the google formatting style.

Answer 2

Your settings are for formatting Google Protocol Buffers (https://developers.google.com/protocol-buffers) or short Protobuf.

If your C++ projects contains Protobuf descriptions the 'google' style formatting is applied.

I assume [pb] is short for Protobuf.