cpython/Programs/python.c

/* Minimal main program -- everything is loaded from the library */

#include "Python.h"
#include <locale.h>

#ifdef __FreeBSD__
#include <fenv.h>
#endif

#ifdef MS_WINDOWS
int
wmain(int argc, wchar_t **argv)
{
    return Py_Main(argc, argv);
}
#else

/* Access private pylifecycle helper API to better handle the legacy C locale
 *
 * The legacy C locale assumes ASCII as the default text encoding, which
 * causes problems not only for the CPython runtime, but also other
 * components like GNU readline.
 *
 * Accordingly, when the CLI detects it, it attempts to coerce it to a
 * more capable UTF-8 based alternative.
 *
 * See the documentation of the PYTHONCOERCECLOCALE setting for more details.
 *
 */
extern int _Py_LegacyLocaleDetected(void);
extern void _Py_CoerceLegacyLocale(void);

int
main(int argc, char **argv)
{
    wchar_t **argv_copy;
    /* We need a second copy, as Python might modify the first one. */
    wchar_t **argv_copy2;
    int i, res;
    char *oldloc;

    /* Force malloc() allocator to bootstrap Python */
#ifdef Py_DEBUG
    (void)_PyMem_SetupAllocators("malloc_debug");
#  else
    (void)_PyMem_SetupAllocators("malloc");
#  endif

    argv_copy = (wchar_t **)PyMem_RawMalloc(sizeof(wchar_t*) * (argc+1));
    argv_copy2 = (wchar_t **)PyMem_RawMalloc(sizeof(wchar_t*) * (argc+1));
    if (!argv_copy || !argv_copy2) {
        fprintf(stderr, "out of memory\n");
        return 1;
    }

    /* 754 requires that FP exceptions run in "no stop" mode by default,
     * and until C vendors implement C99's ways to control FP exceptions,
     * Python requires non-stop mode.  Alas, some platforms enable FP
     * exceptions by default.  Here we disable them.
     */
#ifdef __FreeBSD__
    fedisableexcept(FE_OVERFLOW);
#endif

    oldloc = _PyMem_RawStrdup(setlocale(LC_ALL, NULL));
    if (!oldloc) {
        fprintf(stderr, "out of memory\n");
        return 1;
    }

#ifdef __ANDROID__
    /* Passing "" to setlocale() on Android requests the C locale rather
     * than checking environment variables, so request C.UTF-8 explicitly
     */
    setlocale(LC_ALL, "C.UTF-8");
#else
    /* Reconfigure the locale to the default for this process */
    setlocale(LC_ALL, "");
#endif

    if (_Py_LegacyLocaleDetected()) {
        _Py_CoerceLegacyLocale();
    }

    /* Convert from char to wchar_t based on the locale settings */
    for (i = 0; i < argc; i++) {
        argv_copy[i] = Py_DecodeLocale(argv[i], NULL);
        if (!argv_copy[i]) {
            PyMem_RawFree(oldloc);
            fprintf(stderr, "Fatal Python error: "
                            "unable to decode the command line argument #%i\n",
                            i + 1);
            return 1;
        }
        argv_copy2[i] = argv_copy[i];
    }
    argv_copy2[argc] = argv_copy[argc] = NULL;

    setlocale(LC_ALL, oldloc);
    PyMem_RawFree(oldloc);

    res = Py_Main(argc, argv_copy);

    /* Force again malloc() allocator to release memory blocks allocated
       before Py_Main() */
#ifdef Py_DEBUG
    (void)_PyMem_SetupAllocators("malloc_debug");
#  else
    (void)_PyMem_SetupAllocators("malloc");
#  endif

    for (i = 0; i < argc; i++) {
        PyMem_RawFree(argv_copy2[i]);
    }
    PyMem_RawFree(argv_copy);
    PyMem_RawFree(argv_copy2);
    return res;
}
#endif