fix-client.py

#/bin/python
import sys

print("Fixing wasm client, file: ", sys.argv[1], " output: ")

t_poll  = "function ___syscall_poll"
t_proxy = "if (ENVIRONMENT_IS_PTHREAD)"
t_ret   = "return"
t_end   = ");"

# read all input
with open(sys.argv[1], 'r') as original:
    text = original.read()

# find function sys_poll
ipoll = text.index(t_poll)

#add with AB declaration
text = text[:ipoll] + "const AB = new Int32Array(new SharedArrayBuffer(4));\n" + text[ipoll:]

# find start of proxy call
ipoll = text.index(t_poll)
iret  = text.index(t_proxy, ipoll)
iret  = text.index(t_ret, iret)

# replace with our changes
text = text[:iret] + '{\n  var ret =' + text[iret + len(t_ret):]

# find end of proxy call
iend  = text.index(t_end, iret)
text = text[:iend + len(t_end)] + '\n  if (ret == 0) Atomics.wait(AB, 0, 0, 50);\n  return ret;\n }' + text[iend + len(t_end):]

# replace buffer instanceof SharedArrayBuffer
# to fix https://bugs.chromium.org/p/chromium/issues/detail?id=1269096
text = text.replace("buffer instanceof SharedArrayBuffer", "buffer[Symbol.toStringTag] == 'SharedArrayBuffer'")

#save fixed result
with open(sys.argv[1], 'w') as result:
    result.write(text)