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#!/usr/bin/python
import re
import sys
import copy
import cPickle
import os
class Parser:
def __init__(self):
self.calls = {}
def enter_func(self, name):
if self.infunc and not self.extern:
self.calls.setdefault(self.infunc, set()).update( self.calledfns )
self.calledfns = set()
self.infunc = name
self.extern = False
def parse_callgraph_file(self, inp):
self.infunc = None
self.extern = False
self.calledfns = set()
for line in inp:
m = re.match(r"Call graph node for function: '([^']+)'", line)
if m:
self.enter_func(m.group(1))
continue
m = re.match(r" CS<[^>]+> calls external node", line)
if m:
self.extern = True
m = re.match(r" CS<[^>]+> calls function '([^']+)'", line)
if m:
self.calledfns.add(m.group(1))
self.enter_func(None)
def extract_callgraph(self):
c = self.calls
self.calls = {}
return c
def transitive_closure(g):
passno = 0
changed = True
g = copy.deepcopy(g)
import random
while changed:
passno += 1
changed = False
keys = g.keys()
idx = 0
for k in keys:
idx += 1
print "Pass %d/?: %d/%d\r" %(passno, idx, len(keys)),
sys.stdout.flush()
newset = g[k].copy()
for fn in g[k]:
newset.update(g.get(fn, set()))
if len(newset) != len(g[k]):
g[k].update( newset )
changed = True
print
return g
def strongly_connected_components(g):
# From https://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm, done stupidly.
index_of = {}
index = [ 0 ]
lowlink = {}
S = []
onStack = set()
all_sccs = []
def strongconnect(fn):
index_of[fn] = index[0]
lowlink[fn] = index[0]
index[0] += 1
S.append(fn)
onStack.add(fn)
for w in g.get(fn, []):
if w not in index_of:
strongconnect(w)
lowlink[fn] = min(lowlink[fn], lowlink[w])
elif w in onStack:
lowlink[fn] = min(lowlink[fn], index_of[w])
if lowlink[fn] == index_of[fn]:
this_scc = []
all_sccs.append(this_scc)
while True:
w = S.pop()
onStack.remove(w)
this_scc.append(w)
if w == fn:
break
for v in g.keys():
if v not in index_of:
strongconnect(v)
return all_sccs
def biggest_component(sccs):
return max(len(c) for c in sccs)
def connection_bottlenecks(callgraph):
callers = {}
for fn in callgraph:
for fn2 in callgraph[fn]:
callers.setdefault(fn2, set()).add(fn)
components = strongly_connected_components(callgraph)
components.sort(key=len)
big_component_fns = components[-1]
size = len(big_component_fns)
function_bottlenecks = fn_results = []
total = len(big_component_fns)
idx = 0
for fn in big_component_fns:
idx += 1
print "Pass 1/3: %d/%d\r"%(idx, total),
sys.stdout.flush()
cg2 = copy.deepcopy(callgraph)
del cg2[fn]
fn_results.append( (size - biggest_component(strongly_connected_components(cg2)), fn) )
print
bcf_set = set(big_component_fns)
call_bottlenecks = fn_results = []
result_set = set()
total = len(big_component_fns)
idx = 0
for fn in big_component_fns:
fn_callers = callers[fn].intersection(bcf_set)
idx += 1
if len(fn_callers) != 1:
continue
print "Pass 2/3: %d/%d\r"%(idx, total),
sys.stdout.flush()
caller = fn_callers.pop()
assert len(fn_callers) == 0
cg2 = copy.deepcopy(callgraph)
cg2[caller].remove(fn)
fn_results.append( (size - biggest_component(strongly_connected_components(cg2)), fn, "called by", caller) )
result_set.add( (caller, fn) )
print
total = len(big_component_fns)
idx = 0
for fn in big_component_fns:
fn_calls = callgraph[fn].intersection(bcf_set)
idx += 1
if len(fn_calls) != 1:
continue
print "Pass 3/3: %d/%d\r"%(idx, total),
sys.stdout.flush()
callee = fn_calls.pop()
if (fn, callee) in result_set:
continue
assert len(fn_calls) == 0
cg2 = copy.deepcopy(callgraph)
cg2[fn].remove(callee)
fn_results.append( (size - biggest_component(strongly_connected_components(cg2)), callee, "called by", fn) )
print
return (function_bottlenecks, call_bottlenecks)
if __name__ == '__main__':
p = Parser()
for fname in sys.argv[1:]:
with open(fname, 'r') as f:
p.parse_callgraph_file(f)
sys.stdout.flush
print "Building callgraph"
callgraph = p.extract_callgraph()
print "Finding strongly connected components"
sccs = strongly_connected_components(callgraph)
print "Finding the transitive closure of the callgraph.."
closure = transitive_closure(callgraph)
print "Finding bottlenecks..."
bottlenecks = connection_bottlenecks(callgraph)
data = {
'callgraph' : callgraph,
'sccs' : sccs,
'closure' : closure,
'bottlenecks' : bottlenecks }
with open('callgraph.pkl', 'w') as f:
cPickle.dump(data, f)
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