apenwarr-redo/deps.py
Avery Pennarun 711b05766f Print a better message when detecting pre-existing cyclic dependencies.
We already printed an error at build time, but added the broken
dependency anyway.  If the .do script decided to succeed despite
redo-ifchange aborting, the target would be successfully created
and we'd end up with an infinite loop when running isdirty() later.

The result was still "correct", because python helpfully aborted
the infinite loop after the recursion got too deep.  But let's
explicitly detect it and print a better error message.

(Thanks to Nils Dagsson Moskopp's redo-testcases repo for exposing this
problem.  If you put a #!/bin/sh header on your .do script means you
need to run 'set -e' yourself if you want .do scripts to abort after an
error, which you almost always do, and those testcases don't, which
exposed this bug if you ran the tests twice.)
2018-11-02 02:20:52 -04:00

107 lines
3.8 KiB
Python

import sys, os
import vars, state, builder
from log import debug
CLEAN = 0
DIRTY = 1
def isdirty(f, depth, max_changed,
already_checked,
is_checked=state.File.is_checked,
set_checked=state.File.set_checked_save):
if f.id in already_checked:
raise state.CyclicDependencyError()
# make a copy of the list, so upon returning, our parent's copy
# is unaffected
already_checked = list(already_checked) + [f.id]
if vars.DEBUG >= 1:
debug('%s?%s\n' % (depth, f.nicename()))
if f.failed_runid:
debug('%s-- DIRTY (failed last time)\n' % depth)
return DIRTY
if f.changed_runid == None:
debug('%s-- DIRTY (never built)\n' % depth)
return DIRTY
if f.changed_runid > max_changed:
debug('%s-- DIRTY (built)\n' % depth)
return DIRTY # has been built more recently than parent
if is_checked(f):
if vars.DEBUG >= 1:
debug('%s-- CLEAN (checked)\n' % depth)
return CLEAN # has already been checked during this session
if not f.stamp:
debug('%s-- DIRTY (no stamp)\n' % depth)
return DIRTY
newstamp = f.read_stamp()
if f.stamp != newstamp:
if newstamp == state.STAMP_MISSING:
debug('%s-- DIRTY (missing)\n' % depth)
else:
debug('%s-- DIRTY (mtime)\n' % depth)
if f.csum:
return [f]
else:
return DIRTY
must_build = []
for mode,f2 in f.deps():
dirty = CLEAN
if mode == 'c':
if os.path.exists(os.path.join(vars.BASE, f2.name)):
debug('%s-- DIRTY (created)\n' % depth)
dirty = DIRTY
elif mode == 'm':
sub = isdirty(f2, depth = depth + ' ',
max_changed = max(f.changed_runid,
f.checked_runid),
already_checked=already_checked,
is_checked=is_checked, set_checked=set_checked)
if sub:
debug('%s-- DIRTY (sub)\n' % depth)
dirty = sub
else:
assert(mode in ('c','m'))
if not f.csum:
# f is a "normal" target: dirty f2 means f is instantly dirty
if dirty == DIRTY:
# f2 is definitely dirty, so f definitely needs to
# redo.
return DIRTY
elif isinstance(dirty,list):
# our child f2 might be dirty, but it's not sure yet. It's
# given us a list of targets we have to redo in order to
# be sure.
must_build += dirty
else:
# f is "checksummable": dirty f2 means f needs to redo,
# but f might turn out to be clean after that (ie. our parent
# might not be dirty).
if dirty == DIRTY:
# f2 is definitely dirty, so f definitely needs to
# redo. However, after that, f might turn out to be
# unchanged.
return [f]
elif isinstance(dirty,list):
# our child f2 might be dirty, but it's not sure yet. It's
# given us a list of targets we have to redo in order to
# be sure.
must_build += dirty
if must_build:
# f is *maybe* dirty because at least one of its children is maybe
# dirty. must_build has accumulated a list of "topmost" uncertain
# objects in the tree. If we build all those, we can then
# redo-ifchange f and it won't have any uncertainty next time.
return must_build
debug('%s-- CLEAN\n' % (depth,))
# if we get here, it's because the target is clean
if f.is_override:
state.warn_override(f.name)
set_checked(f)
return CLEAN