Watching for compile_commands.json modifications

[BenjaminNavarro]

It seems to me that if the compile_commands.json file is modified after the initial indexing it does not trigger a re-indexing of the project.

I use ccls trough the atom-ide-ccls plugin and my build system (CMake-based) copies the generatedcompile_commands.json to the root of the project when configured.

Is it a feature lacking to ccls or an issue related to my particular use of it?

Right now, if I add a new file and regenerate the compilation database I have to remove .ccls-cache and reopen the file to trigger a new indexation.

[MaskRay]

It shouldn't be ccls's job to watch compile_commands.json.

The language client can send workspace/didChangeConfiguration to trigger re-indexing.
https://github.com/maskray/ccls/blob/master/src/messages/workspace.cc#L37

void MessageHandler::workspace_didChangeConfiguration(EmptyParam &) {
  for (const std::string &folder : g_config->workspaceFolders)
    project->Load(folder);
  project->Index(wfiles, RequestId());

  manager->Clear();
};

Right now, if I add a new file and regenerate the compilation database

You don't need to regenerate compile_commands.json for a newly added file. When you open the file in your editor, the language client sends textDocument/didOpen, and ccls will infer the compiler flags of that file from an existing file. This is done based on a heuristic comparing file paths.

If you restart ccls, the index of that file will not be loaded initially. You may want to regenerate compile_commands.json before the restart.