Hi Jarkko, On Thu, Sep 6, 2018 at 11:21 AM, Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote: > There is another open. If I grep through the kernel tree I see SPDX > headers that are decorated both with C99- and C89-style comments. I > guess I ended up using C99-style because when I was instructed to add > SPDX headers in the first place that was the example I was given. Still > checkpatch.pl complains about C99-style comments. > > Which one is right and why the kernel tree is polluted with C99-headers > when they do not pass checkpatch.pl? How those commits were ever > accepted? See Documentation/process/license-rules.rst. Headers should go with C-style comments: The SPDX license identifier is added in form of a comment. The comment style depends on the file type:: C source: // SPDX-License-Identifier: <SPDX License Expression> C header: /* SPDX-License-Identifier: <SPDX License Expression> */ And: If a specific tool cannot handle the standard comment style, then the appropriate comment mechanism which the tool accepts shall be used. This is the reason for having the "/\* \*/" style comment in C header files. There was build breakage observed with generated .lds files where 'ld' failed to parse the C++ comment. This has been fixed by now, but there are still older assembler tools which cannot handle C++ style comments. The ones that got in are probably either old or they slipped through (and they do not break the build). Cheers, Miguel