clang-format generated C bindings

[mahesh-hegde]

It's a good idea if generated bindings are formatted consistently.

In theory we can run clang-format on generated .c file once in the generator.

In practice user may open the file in an editor with auto format (Eg VSCode with C++ plugin). Then it will reformat the file. (Yes user should not edit the generated file. But one might open the file and press Ctrl+S out of habit, which will reformat.)

Is it a good idea to copy the .clang-format file from jni package into generated c bindings folder, and format according to that?

[mahesh-hegde]

@dcharkes

Approach 1: Do not format generated bindings

++ No requirement of clang-format tool
-- No consistent formatting

Approach 2: Format using default config

++ No config file required
-- Mismatch with C/C++ style used by dart SDK and package:jni
-- Requires clang-format on user's end.

Approach 3: Copy .clang-format from jni into generated code directory.

++ Consistent with other packages
-- Requires clang-format on user's end.

[dcharkes]

How about we try if we find clang-format and then use it, if we don't find it we output a warning but still continue.

Since we generate the code we could dictate the formatting. Do we need to copy the .clang-format file in, or can we pass clang-format a config file with an argument?

[mahesh-hegde]

Do we need to copy the .clang-format file in

It's not strictly necessary. But imagine a situation

• jnigen generated and formatted C binding with custom config

• User opens C file in VS code

• Doesn't change anything but press Ctrl+S out of habit

• VS code reformats using default clang-format config.

I think it's better to save the custom config than passing it as one time through command line.

[dcharkes]

Yeah that's true.

I wouldn't mind having a config file. I think it is good practise to specify the way code should be formatted, such file does exactly that.

If anyone later on doesn't like it, we can always add a config option to not generate the the formatting file.