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#! /usr/bin/env python
"""Generate C code for the jump table of the threaded code interpreter
(for compilers supporting computed gotos or "labels-as-values", such as gcc).
"""

# This code should stay compatible with Python 2.3, at least while
# some of the buildbots have Python 2.3 as their system Python.

import imp
import os


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]))

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


if __name__ == "__main__":
    import sys
    assert len(sys.argv) < 3, "Too many arguments"
    if len(sys.argv) == 2:
        target = sys.argv[1]
    else:
        target = "Python/opcode_targets.h"
    f = open(target, "w")
    try:
        write_contents(f)
    finally:
        f.close()
opt">); va_end(va); return rc; } int PyOS_vsnprintf(char *str, size_t size, const char *format, va_list va) { int len; /* # bytes written, excluding \0 */ #ifdef HAVE_SNPRINTF #define _PyOS_vsnprintf_EXTRA_SPACE 1 #else #define _PyOS_vsnprintf_EXTRA_SPACE 512 char *buffer; #endif assert(str != NULL); assert(size > 0); assert(format != NULL); /* We take a size_t as input but return an int. Sanity check * our input so that it won't cause an overflow in the * vsnprintf return value or the buffer malloc size. */ if (size > INT_MAX - _PyOS_vsnprintf_EXTRA_SPACE) { len = -666; goto Done; } #ifdef HAVE_SNPRINTF len = vsnprintf(str, size, format, va); #else /* Emulate it. */ buffer = PyMem_MALLOC(size + _PyOS_vsnprintf_EXTRA_SPACE); if (buffer == NULL) { len = -666; goto Done; } len = vsprintf(buffer, format, va); if (len < 0) /* ignore the error */; else if ((size_t)len >= size + _PyOS_vsnprintf_EXTRA_SPACE) Py_FatalError("Buffer overflow in PyOS_snprintf/PyOS_vsnprintf"); else { const size_t to_copy = (size_t)len < size ? (size_t)len : size - 1; assert(to_copy < size); memcpy(str, buffer, to_copy); str[to_copy] = '\0'; } PyMem_FREE(buffer); #endif Done: if (size > 0) str[size-1] = '\0'; return len; #undef _PyOS_vsnprintf_EXTRA_SPACE }