_freeze_module.py

"""Python implementation of Programs/_freeze_module.c

The pure Python implementation uses same functions and arguments as the C
implementation.

The generated byte code is slightly different because
compile() sets the PyCF_SOURCE_IS_UTF8 flag and objects have a
reference count > 1. Marshal adds the `FLAG_REF` flag and creates a
reference `hashtable`.
"""

importmarshal
importsys

header="/* Auto-generated by Programs/_freeze_module.py */"


defread_text(inpath: str) ->bytes:
withopen(inpath, "rb") asf:
returnf.read()


defcompile_and_marshal(name: str, text: bytes) ->bytes:
filename=f"<frozen {name}>"
# exec == Py_file_input
code=compile(text, filename, "exec", optimize=0, dont_inherit=True)
returnmarshal.dumps(code)


defget_varname(name: str, prefix: str) ->str:
returnf"{prefix}{name.replace('.', '_')}"


defwrite_code(outfile, marshalled: bytes, varname: str) ->None:
data_size=len(marshalled)

outfile.write(f"const unsigned char {varname}[] = {{\n")

forninrange(0, data_size, 16):
outfile.write(" ")
outfile.write(",".join(str(i) foriinmarshalled[n : n+16]))
outfile.write(",\n")
outfile.write("};\n")


defwrite_frozen(outpath: str, inpath: str, name: str, marshalled: bytes) ->None:
withopen(outpath, "w") asoutfile:
outfile.write(header)
outfile.write("\n")
arrayname=get_varname(name, "_Py_M__")
write_code(outfile, marshalled, arrayname)


defmain():
iflen(sys.argv) !=4:
sys.exit("need to specify the name, input and output paths\n")

name=sys.argv[1]
inpath=sys.argv[2]
outpath=sys.argv[3]

text=read_text(inpath)
marshalled=compile_and_marshal(name, text)
write_frozen(outpath, inpath, name, marshalled)


if__name__=="__main__":
main()