It's time to start preparing for a version of redo that doesn't work
unless we build it first (because it will rely on C modules, and
eventually be rewritten in C altogether).
To get rolling, remove the old-style symlinks to the main programs, and
rename those programs from redo-*.py to redo/cmd_*.py. We'll also move
all library functions into the redo/ dir, which is a more python-style
naming convention.
Previously, install.do was generating wrappers for installing in
/usr/bin, which extend sys.path and then import+run the right file.
This made "installed" redo work quite differently from running redo
inside its source tree. Instead, let's always generate the wrappers in
bin/, and not make anything executable except those wrappers.
Since we're generating wrappers anyway, let's actually auto-detect the
right version of python for the running system; distros can't seem to
agree on what to call their python2 binaries (sigh). We'll fill in the
right #! shebang lines. Since we're doing that, we can stop using
/usr/bin/env, which will a) make things slightly faster, and b) let us
use "python -S", which tells python not to load a bunch of extra crap
we're not using, thus improving startup times.
Annoyingly, we now have to build redo using minimal/do, then run the
tests using bin/redo. To make this less annoying, we add a toplevel
./do script that knows the right steps, and a Makefile (whee!) for
people who are used to typing 'make' and 'make test' and 'make clean'.
Suggested by djb in personal email, and on the mailing list. redo-targets
lists all the targets in the database; redo-sources lists all the existing
sources (ie. files that are referred to but which aren't targets).
redo-ifcreate filenames aren't included in the redo-sources list.
The interaction of REDO_STARTDIR, REDO_PWD, and getcwd() are pretty
complicated. In this case, we accidentally assumed that the current
instance of redo was running with getcwd() == REDO_STARTDIR+REDO_PWD, and so
the new target was REDO_STARTDIR+REDO_PWD+t, but this isn't the case if the
current .do script did chdir().
The correct answer is REDO_STARTDIR+getcwd()+t.
If 'redo clean' deletes the lockfile after trylock() succeeds but before
unlock(), then unlock() won't be able to open the pipe in order to release
readers, and any waiters might end up waiting forever.
We can't open the fifo for write until there's at least one reader, so let's
open a reader *just* to let us open a writer. Then we'll leave them open
until the later unlock(), which can just close them both.
Now t/curse passes again when parallelized (except for the countall
mismatch, since we haven't fixed the source of that problem yet). At least
it's consistent now.
There's a bunch of stuff rearranged in here, but the actual important
problem was that we were doing unlink() on the lock fifo even if ENXIO,
which meant a reader could connect in between ENXIO and unlink(), and thus
never get notified of the disconnection. This would cause the build to
randomly freeze.
The problem is that redo-ifchange has a different $PWD than its
sub-dependencies, so as it's chasing them down, fixing up the relative paths
totally doesn't work at all.
There's probably a much smarter fix than this, but it's too late at night to
think of it right now.
atoi() was getting redundant, and unfortunately we can't easily load
helpers.py in some places where we'd want to, because it depends on vars.py.
So move it to its own module.
It used to say:
redo: t/all
redo: hello
and now it says:
redo t/all
redo t/hello
ie. there's no colon, and the path is intact. That means if the build
fails, you can cut-and-paste 'redo t/hello', add a -v, and try to debug
what went wrong.
