1#! /usr/bin/env python
2"""Generate C code for the jump table of the threaded code interpreter
3(for compilers supporting computed gotos or "labels-as-values", such as gcc).
4"""
5
6# This code should stay compatible with Python 2.3, at least while
7# some of the buildbots have Python 2.3 as their system Python.
8
9import imp
10import os
11
12
13def find_module(modname):
14    """Finds and returns a module in the local dist/checkout.
15    """
16    modpath = os.path.join(
17        os.path.dirname(os.path.dirname(__file__)), "Lib")
18    return imp.load_module(modname, *imp.find_module(modname, [modpath]))
19
20def write_contents(f):
21    """Write C code contents to the target file object.
22    """
23    opcode = find_module("opcode")
24    targets = ['_unknown_opcode'] * 256
25    for opname, op in opcode.opmap.items():
26        if opname == "STOP_CODE":
27            continue
28        targets[op] = "TARGET_%s" % opname.replace("+0", " ").replace("+", "_")
29    f.write("static void *opcode_targets[256] = {\n")
30    f.write(",\n".join(["    &&%s" % s for s in targets]))
31    f.write("\n};\n")
32
33
34if __name__ == "__main__":
35    import sys
36    assert len(sys.argv) < 3, "Too many arguments"
37    if len(sys.argv) == 2:
38        target = sys.argv[1]
39    else:
40        target = "Python/opcode_targets.h"
41    f = open(target, "w")
42    try:
43        write_contents(f)
44    finally:
45        f.close()
46