[PATCH] [clang-tidy] Add a checker for long functions.

[Alexander Kornienko]

I wonder if any style guides define function size threshold in terms of cyclomatic complexity? Is it actually useful as a warning? It may be interesting to developers looking for a place in their code to start refactoring from, but this task requires a bit different representation of the results - tables or charts; diagnostic messages are sub-optimal here. I also think, that at the point you start needing a CFG, the check becomes closer to the static analyzer realm, as it provides more useful tools for path-based analysis.

http://reviews.llvm.org/D4986