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
|
#!/usr/bin/env python3
#
# Copyright 2016 WebAssembly Community Group participants
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
'''
This fuzzes passes, by starting with a wast, then running
random passes on the wast, and seeing if they break optimization
or validation
Usage: Provide the filename of the wast.
'''
from __future__ import print_function
import os
import random
import shutil
import subprocess
import sys
PASSES = [
"duplicate-function-elimination",
"dce",
"remove-unused-brs",
"remove-unused-names",
"optimize-instructions",
"precompute",
"simplify-locals",
"vacuum",
"coalesce-locals",
"reorder-locals",
"merge-blocks",
"remove-unused-functions",
]
# main
wast = sys.argv[1]
print('>>> wast:', wast)
args = sys.argv[2:]
def run():
try:
cmd = ['bin/wasm-opt', wast]
print('run', cmd)
subprocess.check_call(cmd, stderr=open('/dev/null'))
except Exception as e:
return ">>> !!! ", e, " !!!"
return 'ok'
original_wast = None
try:
# get normal output
normal = run()
print('>>> normal output:\n', normal)
assert normal, 'must be output'
# ensure we actually use the wast
original_wast = wast + '.original.wast'
shutil.move(wast, original_wast)
def apply_passes(passes):
wasm_opt = os.path.join('bin', 'wasm-opt')
subprocess.check_call([wasm_opt, original_wast] + passes + ['-o', wast],
stderr=open('/dev/null'))
# loop, looking for failures
def simplify(passes):
# passes is known to fail, try to simplify down by removing
more = True
while more:
more = False
print('>>> trying to reduce:', ' '.join(passes), ' [' + str(len(passes)) + ']')
for i in range(len(passes)):
smaller = passes[:i] + passes[i + 1:]
print('>>>>>> try to reduce to:', ' '.join(smaller), ' [' + str(len(smaller)) + ']')
try:
apply_passes(smaller)
assert run() == normal
except Exception:
# this failed too, so it's a good reduction
passes = smaller
print('>>> reduction successful')
more = True
break
print('>>> reduced to:', ' '.join(passes))
tested = set()
def pick_passes():
# return '--waka'.split(' ')
ret = []
while 1:
str_ret = str(ret)
if random.random() < 0.5 and str_ret not in tested:
tested.add(str_ret)
return ret
ret.append('--' + random.choice(PASSES))
counter = 0
while 1:
passes = pick_passes()
print('>>> [' + str(counter) + '] testing:', ' '.join(passes))
counter += 1
try:
apply_passes(passes)
except Exception as e:
print(e)
simplify(passes)
break
seen = run()
if seen != normal:
print('>>> bad output:\n', seen)
simplify(passes)
break
finally:
if original_wast:
shutil.move(original_wast, wast)
|
