From 6acb10fc71441e95909398a59906b18e04cf314d Mon Sep 17 00:00:00 2001 From: Christian Neukirchen Date: Sun, 6 Sep 2015 19:40:27 +0200 Subject: Add NOTES --- NOTES | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 NOTES diff --git a/NOTES b/NOTES new file mode 100644 index 0000000..0df7a6b --- /dev/null +++ b/NOTES @@ -0,0 +1,32 @@ += Notes about the redo-c implementation of redo + +* Without arguments, `redo` behaves like `redo all`. + +* `.do` files always are executed in their directory, arguments are + relative paths. + +* Standard output of `.do` files is only captured as build product if + `redo -s` is used, or the environment variable `REDO_STDOUT` is set to 1. + Else, standard output is simply displayed. + +* Non-executable `.do` files are run with `/bin/sh -e`. + `redo -x` can be utilized to use `/bin/sh -e -x` instead, for + debugging `.do` files or verbose builds. + +* Executable `.do` files are simply executed, and should have a shebang line. + +* When a target makes no output, no target file is created. The target + is considered always out of date. + +* `default.do` files are checked in all parent directories up to `/`. + +* Parallel builds can be started with `redo -j N`, this uses a job + broker similar to but not compatible with GNU make. + +* To detect whether a file has changed, we first compare `ctime` and + in case it differs, a SHA2 hash of the contents. + +* Dependencies are tracked in `.dep.BASENAME` files all over the tree. + This is an implementation detail. + +* Builds can be started from every directory and should yield same results. -- cgit 1.4.1