commit 4793d913503f9349ca4b57d77a47bd1bbceecfe5 Author: Nick Mathewson <nickm@torproject.org> Date: Tue Jul 10 11:09:25 2018 -0400 Describe "check-includes" in the CodingStandards.md file --- doc/HACKING/CodingStandards.md | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/doc/HACKING/CodingStandards.md b/doc/HACKING/CodingStandards.md index 6e6ef044d..4f229348e 100644 --- a/doc/HACKING/CodingStandards.md +++ b/doc/HACKING/CodingStandards.md @@ -214,6 +214,24 @@ We don't call `memcmp()` directly. Use `fast_memeq()`, `fast_memneq()`, Also see a longer list of functions to avoid in: https://people.torproject.org/~nickm/tor-auto/internal/this-not-that.html +What code can use what other code? +---------------------------------- + +We're trying to simplify Tor's structure over time. In the long run, we want +Tor to be structured as a set of modules with *no circular dependencies*. + +This property is currently provided by the modules in src/lib, but not +throughout the rest of Tor. In general, higher-level libraries may use +lower-level libraries, but never the reverse. + +To prevent new circular dependencies from landing, we have a tool that +you can invoke with `make check-includes`, and which is run +automatically as part of `make check`. This tool will verify that, for +every source directory with a `.may_include` file, no local headers are +included except those specifically permitted by the `.may_include` file. +When editing one of these files, please make sure that you are not +introducing any cycles into Tor's dependency graph. + Floating point math is hard ---------------------------