makeopcodetargets.py 1.55 KB
Newer Older
1
#! /usr/bin/env python
2 3 4 5 6
"""Generate C code for the jump table of the threaded code interpreter
(for compilers supporting computed gotos or "labels-as-values", such as gcc).
"""

import os
7
import sys
8 9


10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
try:
    from importlib.machinery import SourceFileLoader
except ImportError:
    import imp

    def find_module(modname):
        """Finds and returns a module in the local dist/checkout.
        """
        modpath = os.path.join(
            os.path.dirname(os.path.dirname(__file__)), "Lib")
        return imp.load_module(modname, *imp.find_module(modname, [modpath]))
else:
    def find_module(modname):
        """Finds and returns a module in the local dist/checkout.
        """
        modpath = os.path.join(
            os.path.dirname(os.path.dirname(__file__)), "Lib", modname + ".py")
        return SourceFileLoader(modname, modpath).load_module()


30 31 32
def write_contents(f):
    """Write C code contents to the target file object.
    """
33
    opcode = find_module('opcode')
34 35 36 37
    targets = ['_unknown_opcode'] * 256
    for opname, op in opcode.opmap.items():
        targets[op] = "TARGET_%s" % opname
    f.write("static void *opcode_targets[256] = {\n")
38
    f.write(",\n".join(["    &&%s" % s for s in targets]))
39 40 41
    f.write("\n};\n")


42 43 44
def main():
    if len(sys.argv) >= 3:
        sys.exit("Too many arguments")
45 46 47 48
    if len(sys.argv) == 2:
        target = sys.argv[1]
    else:
        target = "Python/opcode_targets.h"
49
    with open(target, "w") as f:
50
        write_contents(f)
51 52 53 54 55
    print("Jump table written into %s" % target)


if __name__ == "__main__":
    main()