From f48c08f0f58cf99268a1f6be1edf96e5438a83b1 Mon Sep 17 00:00:00 2001 From: "Yann E. MORIN" Date: Sun, 7 Feb 2016 22:34:27 +0100 Subject: [PATCH] support/graph-depends: detect circular dependencies Currently, if there is a circular dependency in the packages, the graph-depends script just errors out with a Python RuntimeError which is not caught, resulting in a very-long backtrace which does not provide any hint as what the real issue is (even if "RuntimeError: maximum recursion depth exceeded" is a pretty good hint at it). We fix that by recursing the dependency chain of each package, until we either end up with a package with no dependency, or with a package already seen along the current dependency chain. We need to introduce a new function, check_circular_deps(), because we can't re-use the existing ones: - remove_mandatory_deps() does not iterate, - remove_transitive_deps() does iterate, but we do not call it for the top-level package if it is not 'all' - it does not make sense to use those functions anyway, as they were not designed to _check_ but to _act_ on the dependency chain. Since we've had time-related issues in the past, we do not want to introduce yet another time-hog, so here are timings with the circular dependency check: $ time python -m cProfile -s cumtime support/scripts/graph-depends [...] 28352654 function calls (20323050 primitive calls) in 87.292 seconds Ordered by: cumulative time ncalls tottime percall cumtime percall filename:lineno(function) 1 0.012 0.012 87.292 87.292 graph-depends:24() 21 0.000 0.000 73.685 3.509 subprocess.py:473(_eintr_retry_call) 7 0.000 0.000 73.655 10.522 subprocess.py:768(communicate) 7 73.653 10.522 73.653 10.522 {method 'read' of 'file' objects} 5/1 0.027 0.005 43.488 43.488 graph-depends:164(get_all_depends) 5 0.003 0.001 43.458 8.692 graph-depends:135(get_depends) 1 0.001 0.001 25.712 25.712 graph-depends:98(get_version) 1 0.001 0.001 13.457 13.457 graph-depends:337(remove_extra_deps) 1717 1.672 0.001 13.050 0.008 graph-depends:290(remove_transitive_deps) 9784086/2672326 5.079 0.000 11.363 0.000 graph-depends:274(is_dep) 2883343/1980154 2.650 0.000 6.942 0.000 graph-depends:262(is_dep_uncached) 1 0.000 0.000 4.529 4.529 graph-depends:121(get_targets) 2883343 1.123 0.000 1.851 0.000 graph-depends:246(is_dep_cache_insert) 9784086 1.783 0.000 1.783 0.000 graph-depends:255(is_dep_cache_lookup) 2881580 0.728 0.000 0.728 0.000 {method 'update' of 'dict' objects} 1 0.001 0.001 0.405 0.405 graph-depends:311(check_circular_deps) 12264/1717 0.290 0.000 0.404 0.000 graph-depends:312(recurse) [...] real 1m27.371s user 1m15.075s sys 0m12.673s The cumulative time spent in check_circular_deps is just below 0.5s, which is largely less than 1% of the total run time. Signed-off-by: "Yann E. MORIN" Cc: Thomas Petazzoni Cc: Samuel Martin Signed-off-by: Thomas Petazzoni --- support/scripts/graph-depends | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/support/scripts/graph-depends b/support/scripts/graph-depends index c0c6a94a21..d933eaae12 100755 --- a/support/scripts/graph-depends +++ b/support/scripts/graph-depends @@ -313,6 +313,32 @@ def remove_transitive_deps(pkg,deps): def remove_mandatory_deps(pkg,deps): return [p for p in deps[pkg] if p not in ['toolchain', 'skeleton']] +# This function will check that there is no loop in the dependency chain +# As a side effect, it builds up the dependency cache. +def check_circular_deps(deps): + def recurse(pkg): + if not pkg in list(deps.keys()): + return + if pkg in not_loop: + return + not_loop.append(pkg) + chain.append(pkg) + for p in deps[pkg]: + if p in chain: + sys.stderr.write("\nRecursion detected for : %s\n" % (p)) + while True: + _p = chain.pop() + sys.stderr.write("which is a dependency of: %s\n" % (_p)) + if p == _p: + sys.exit(1) + recurse(p) + chain.pop() + + not_loop = [] + chain = [] + for pkg in list(deps.keys()): + recurse(pkg) + # This functions trims down the dependency list of all packages. # It applies in sequence all the dependency-elimination methods. def remove_extra_deps(deps): @@ -324,6 +350,7 @@ def remove_extra_deps(deps): deps[pkg] = remove_transitive_deps(pkg,deps) return deps +check_circular_deps(dict_deps) dict_deps = remove_extra_deps(dict_deps) dict_version = get_version([pkg for pkg in allpkgs if pkg != "all" and not pkg.startswith("root")])