1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
#! /usr/bin/env python
# To use:
# 1) Update the 'decls' list below with your fuzzing configuration.
# 2) Run with the clang binary as the command-line argument.
import random
import subprocess
import sys
import os
clang = sys.argv[1]
none_opts = 0.3
class Decl:
def __init__(self, text, depends=[], provides=[], conflicts=[]):
self.text = text
self.depends = depends
self.provides = provides
self.conflicts = conflicts
def valid(self, model):
for i in self.depends:
if i not in model.decls:
return False
for i in self.conflicts:
if i in model.decls:
return False
return True
def apply(self, model, name):
for i in self.provides:
model.decls[i] = True
model.source += self.text % {'name': name}
decls = [
Decl('struct X { int n; };\n', provides=['X'], conflicts=['X']),
Decl('static_assert(X{.n=1}.n == 1, "");\n', depends=['X']),
Decl('X %(name)s;\n', depends=['X']),
]
class FS:
def __init__(self):
self.fs = {}
self.prevfs = {}
def write(self, path, contents):
self.fs[path] = contents
def done(self):
for f, s in self.fs.items():
if self.prevfs.get(f) != s:
f = file(f, 'w')
f.write(s)
f.close()
for f in self.prevfs:
if f not in self.fs:
os.remove(f)
self.prevfs, self.fs = self.fs, {}
fs = FS()
class CodeModel:
def __init__(self):
self.source = ''
self.modules = {}
self.decls = {}
self.i = 0
def make_name(self):
self.i += 1
return 'n' + str(self.i)
def fails(self):
fs.write('module.modulemap',
''.join('module %s { header "%s.h" export * }\n' % (m, m)
for m in self.modules.keys()))
for m, (s, _) in self.modules.items():
fs.write('%s.h' % m, s)
fs.write('main.cc', self.source)
fs.done()
return subprocess.call([clang, '-std=c++11', '-c', '-fmodules', 'main.cc', '-o', '/dev/null']) != 0
def generate():
model = CodeModel()
m = []
try:
for d in mutations(model):
d(model)
m.append(d)
if not model.fails():
return
except KeyboardInterrupt:
print
return True
sys.stdout.write('\nReducing:\n')
sys.stdout.flush()
try:
while True:
assert m, 'got a failure with no steps; broken clang binary?'
i = random.choice(range(len(m)))
x = m[0:i] + m[i+1:]
m2 = CodeModel()
for d in x:
d(m2)
if m2.fails():
m = x
model = m2
else:
sys.stdout.write('.')
sys.stdout.flush()
except KeyboardInterrupt:
# FIXME: Clean out output directory first.
model.fails()
return model
def choose(options):
while True:
i = int(random.uniform(0, len(options) + none_opts))
if i >= len(options):
break
yield options[i]
def mutations(model):
options = [create_module, add_top_level_decl]
for opt in choose(options):
yield opt(model, options)
def create_module(model, options):
n = model.make_name()
def go(model):
model.modules[n] = (model.source, model.decls)
(model.source, model.decls) = ('', {})
options += [lambda model, options: add_import(model, options, n)]
return go
def add_top_level_decl(model, options):
n = model.make_name()
d = random.choice([decl for decl in decls if decl.valid(model)])
def go(model):
if not d.valid(model):
return
d.apply(model, n)
return go
def add_import(model, options, module_name):
def go(model):
if module_name in model.modules:
model.source += '#include "%s.h"\n' % module_name
model.decls.update(model.modules[module_name][1])
return go
sys.stdout.write('Finding bug: ')
while True:
if generate():
break
sys.stdout.write('.')
sys.stdout.flush()
|
