getargs.c

/* New getargs implementation */

#include "Python.h"

#include <ctype.h>
#include <float.h>


#ifdef __cplusplus
extern "C" {
#endif
int PyArg_Parse(PyObject *, const char *, ...);
int PyArg_ParseTuple(PyObject *, const char *, ...);
int PyArg_VaParse(PyObject *, const char *, va_list);

int PyArg_ParseTupleAndKeywords(PyObject *, PyObject *,
                                const char *, char **, ...);
int PyArg_VaParseTupleAndKeywords(PyObject *, PyObject *,
                                const char *, char **, va_list);

int _PyArg_ParseTupleAndKeywordsFast(PyObject *, PyObject *,
                                            struct _PyArg_Parser *, ...);
int _PyArg_VaParseTupleAndKeywordsFast(PyObject *, PyObject *,
                                            struct _PyArg_Parser *, va_list);

#ifdef HAVE_DECLSPEC_DLL
/* Export functions */
PyAPI_FUNC(int) _PyArg_Parse_SizeT(PyObject *, const char *, ...);
PyAPI_FUNC(int) _PyArg_ParseStack_SizeT(PyObject **args, Py_ssize_t nargs, PyObject *kwnames,
                                        struct _PyArg_Parser *parser, ...);
PyAPI_FUNC(int) _PyArg_ParseTuple_SizeT(PyObject *, const char *, ...);
PyAPI_FUNC(int) _PyArg_ParseTupleAndKeywords_SizeT(PyObject *, PyObject *,
                                                  const char *, char **, ...);
PyAPI_FUNC(PyObject *) _Py_BuildValue_SizeT(const char *, ...);
PyAPI_FUNC(int) _PyArg_VaParse_SizeT(PyObject *, const char *, va_list);
PyAPI_FUNC(int) _PyArg_VaParseTupleAndKeywords_SizeT(PyObject *, PyObject *,
                                              const char *, char **, va_list);

PyAPI_FUNC(int) _PyArg_ParseTupleAndKeywordsFast_SizeT(PyObject *, PyObject *,
                                            struct _PyArg_Parser *, ...);
PyAPI_FUNC(int) _PyArg_VaParseTupleAndKeywordsFast_SizeT(PyObject *, PyObject *,
                                            struct _PyArg_Parser *, va_list);
#endif

#define FLAG_COMPAT 1
#define FLAG_SIZE_T 2

typedef int (*destr_t)(PyObject *, void *);


/* Keep track of "objects" that have been allocated or initialized and
   which will need to be deallocated or cleaned up somehow if overall
   parsing fails.
*/
typedef struct {
  void *item;
  destr_t destructor;
} freelistentry_t;

typedef struct {
  freelistentry_t *entries;
  int first_available;
  int entries_malloced;
} freelist_t;

#define STATIC_FREELIST_ENTRIES 8

/* Forward */
static int vgetargs1(PyObject *, const char *, va_list *, int);
static void seterror(Py_ssize_t, const char *, int *, const char *, const char *);
static const char *convertitem(PyObject *, const char **, va_list *, int, int *,
                               char *, size_t, freelist_t *);
static const char *converttuple(PyObject *, const char **, va_list *, int,
                                int *, char *, size_t, int, freelist_t *);
static const char *convertsimple(PyObject *, const char **, va_list *, int,
                                 char *, size_t, freelist_t *);
static Py_ssize_t convertbuffer(PyObject *, void **p, const char **);
static int getbuffer(PyObject *, Py_buffer *, const char**);

static int vgetargskeywords(PyObject *, PyObject *,
                            const char *, char **, va_list *, int);
static int vgetargskeywordsfast(PyObject *, PyObject *,
                            struct _PyArg_Parser *, va_list *, int);
static int vgetargskeywordsfast_impl(PyObject **args, Py_ssize_t nargs,
                          PyObject *keywords, PyObject *kwnames,
                          struct _PyArg_Parser *parser,
                          va_list *p_va, int flags);
static const char *skipitem(const char **, va_list *, int);

int
PyArg_Parse(PyObject *args, const char *format, ...)
{
    int retval;
    va_list va;

    va_start(va, format);
    retval = vgetargs1(args, format, &va, FLAG_COMPAT);
    va_end(va);
    return retval;
}

int
_PyArg_Parse_SizeT(PyObject *args, const char *format, ...)
{
    int retval;
    va_list va;

    va_start(va, format);
    retval = vgetargs1(args, format, &va, FLAG_COMPAT|FLAG_SIZE_T);
    va_end(va);
    return retval;
}


int
PyArg_ParseTuple(PyObject *args, const char *format, ...)
{
    int retval;
    va_list va;

    va_start(va, format);
    retval = vgetargs1(args, format, &va, 0);
    va_end(va);
    return retval;
}

int
_PyArg_ParseTuple_SizeT(PyObject *args, const char *format, ...)
{
    int retval;
    va_list va;

    va_start(va, format);
    retval = vgetargs1(args, format, &va, FLAG_SIZE_T);
    va_end(va);
    return retval;
}


int
PyArg_VaParse(PyObject *args, const char *format, va_list va)
{
    va_list lva;
    int retval;

    va_copy(lva, va);

    retval = vgetargs1(args, format, &lva, 0);
    va_end(lva);
    return retval;
}

int
_PyArg_VaParse_SizeT(PyObject *args, const char *format, va_list va)
{
    va_list lva;
    int retval;

    va_copy(lva, va);

    retval = vgetargs1(args, format, &lva, FLAG_SIZE_T);
    va_end(lva);
    return retval;
}


/* Handle cleanup of allocated memory in case of exception */

static int
cleanup_ptr(PyObject *self, void *ptr)
{
    if (ptr) {
        PyMem_FREE(ptr);
    }
    return 0;
}

static int
cleanup_buffer(PyObject *self, void *ptr)
{
    Py_buffer *buf = (Py_buffer *)ptr;
    if (buf) {
        PyBuffer_Release(buf);
    }
    return 0;
}

static int
addcleanup(void *ptr, freelist_t *freelist, destr_t destructor)
{
    int index;

    index = freelist->first_available;
    freelist->first_available += 1;

    freelist->entries[index].item = ptr;
    freelist->entries[index].destructor = destructor;

    return 0;
}

static int
cleanreturn(int retval, freelist_t *freelist)
{
    int index;

    if (retval == 0) {
      /* A failure occurred, therefore execute all of the cleanup
         functions.
      */
      for (index = 0; index < freelist->first_available; ++index) {
          freelist->entries[index].destructor(NULL,
                                              freelist->entries[index].item);
      }
    }
    if (freelist->entries_malloced)
        PyMem_FREE(freelist->entries);
    return retval;
}


static int
vgetargs1(PyObject *args, const char *format, va_list *p_va, int flags)
{
    char msgbuf[256];
    int levels[32];
    const char *fname = NULL;
    const char *message = NULL;
    int min = -1;
    int max = 0;
    int level = 0;
    int endfmt = 0;
    const char *formatsave = format;
    Py_ssize_t i, len;
    const char *msg;
    int compat = flags & FLAG_COMPAT;
    freelistentry_t static_entries[STATIC_FREELIST_ENTRIES];
    freelist_t freelist;

    freelist.entries = static_entries;
    freelist.first_available = 0;
    freelist.entries_malloced = 0;

    assert(compat || (args != (PyObject*)NULL));
    flags = flags & ~FLAG_COMPAT;

    while (endfmt == 0) {
        int c = *format++;
        switch (c) {
        case '(':
            if (level == 0)
                max++;
            level++;
            if (level >= 30)
                Py_FatalError("too many tuple nesting levels "
                              "in argument format string");
            break;
        case ')':
            if (level == 0)
                Py_FatalError("excess ')' in getargs format");
            else
                level--;
            break;
        case '\0':
            endfmt = 1;
            break;
        case ':':
            fname = format;
            endfmt = 1;
            break;
        case ';':
            message = format;
            endfmt = 1;
            break;
        case '|':
            if (level == 0)
                min = max;
            break;
        default:
            if (level == 0) {
                if (Py_ISALPHA(Py_CHARMASK(c)))
                    if (c != 'e') /* skip encoded */
                        max++;
            }
            break;
        }
    }

    if (level != 0)
        Py_FatalError(/* '(' */ "missing ')' in getargs format");

    if (min < 0)
        min = max;

    format = formatsave;

    if (max > STATIC_FREELIST_ENTRIES) {
        freelist.entries = PyMem_NEW(freelistentry_t, max);
        if (freelist.entries == NULL) {
            PyErr_NoMemory();
            return 0;
        }
        freelist.entries_malloced = 1;
    }

    if (compat) {
        if (max == 0) {
            if (args == NULL)
                return 1;
            PyErr_Format(PyExc_TypeError,
                         "%.200s%s takes no arguments",
                         fname==NULL ? "function" : fname,
                         fname==NULL ? "" : "()");
            return cleanreturn(0, &freelist);
        }
        else if (min == 1 && max == 1) {
            if (args == NULL) {
                PyErr_Format(PyExc_TypeError,
                             "%.200s%s takes at least one argument",
                             fname==NULL ? "function" : fname,
                             fname==NULL ? "" : "()");
                return cleanreturn(0, &freelist);
            }
            msg = convertitem(args, &format, p_va, flags, levels,
                              msgbuf, sizeof(msgbuf), &freelist);
            if (msg == NULL)
                return cleanreturn(1, &freelist);
            seterror(levels[0], msg, levels+1, fname, message);
            return cleanreturn(0, &freelist);
        }
        else {
            PyErr_SetString(PyExc_SystemError,
                "old style getargs format uses new features");
            return cleanreturn(0, &freelist);
        }
    }

    if (!PyTuple_Check(args)) {
        PyErr_SetString(PyExc_SystemError,
            "new style getargs format but argument is not a tuple");
        return cleanreturn(0, &freelist);
    }

    len = PyTuple_GET_SIZE(args);

    if (len < min || max < len) {
        if (message == NULL)
            PyErr_Format(PyExc_TypeError,
                         "%.150s%s takes %s %d argument%s (%ld given)",
                         fname==NULL ? "function" : fname,
                         fname==NULL ? "" : "()",
                         min==max ? "exactly"
                         : len < min ? "at least" : "at most",
                         len < min ? min : max,
                         (len < min ? min : max) == 1 ? "" : "s",
                         Py_SAFE_DOWNCAST(len, Py_ssize_t, long));
        else
            PyErr_SetString(PyExc_TypeError, message);
        return cleanreturn(0, &freelist);
    }

    for (i = 0; i < len; i++) {
        if (*format == '|')
            format++;
        msg = convertitem(PyTuple_GET_ITEM(args, i), &format, p_va,
                          flags, levels, msgbuf,
                          sizeof(msgbuf), &freelist);
        if (msg) {
            seterror(i+1, msg, levels, fname, message);
            return cleanreturn(0, &freelist);
        }
    }

    if (*format != '\0' && !Py_ISALPHA(Py_CHARMASK(*format)) &&
        *format != '(' &&
        *format != '|' && *format != ':' && *format != ';') {
        PyErr_Format(PyExc_SystemError,
                     "bad format string: %.200s", formatsave);
        return cleanreturn(0, &freelist);
    }

    return cleanreturn(1, &freelist);
}



static void
seterror(Py_ssize_t iarg, const char *msg, int *levels, const char *fname,
         const char *message)
{
    char buf[512];
    int i;
    char *p = buf;

    if (PyErr_Occurred())
        return;
    else if (message == NULL) {
        if (fname != NULL) {
            PyOS_snprintf(p, sizeof(buf), "%.200s() ", fname);
            p += strlen(p);
        }
        if (iarg != 0) {
            PyOS_snprintf(p, sizeof(buf) - (p - buf),
                          "argument %" PY_FORMAT_SIZE_T "d", iarg);
            i = 0;
            p += strlen(p);
            while (i < 32 && levels[i] > 0 && (int)(p-buf) < 220) {
                PyOS_snprintf(p, sizeof(buf) - (p - buf),
                              ", item %d", levels[i]-1);
                p += strlen(p);
                i++;
            }
        }
        else {
            PyOS_snprintf(p, sizeof(buf) - (p - buf), "argument");
            p += strlen(p);
        }
        PyOS_snprintf(p, sizeof(buf) - (p - buf), " %.256s", msg);
        message = buf;
    }
    if (msg[0] == '(') {
        PyErr_SetString(PyExc_SystemError, message);
    }
    else {
        PyErr_SetString(PyExc_TypeError, message);
    }
}


/* Convert a tuple argument.
   On entry, *p_format points to the character _after_ the opening '('.
   On successful exit, *p_format points to the closing ')'.
   If successful:
      *p_format and *p_va are updated,
      *levels and *msgbuf are untouched,
      and NULL is returned.
   If the argument is invalid:
      *p_format is unchanged,
      *p_va is undefined,
      *levels is a 0-terminated list of item numbers,
      *msgbuf contains an error message, whose format is:
     "must be <typename1>, not <typename2>", where:
        <typename1> is the name of the expected type, and
        <typename2> is the name of the actual type,
      and msgbuf is returned.
*/

static const char *
converttuple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
             int *levels, char *msgbuf, size_t bufsize, int toplevel,
             freelist_t *freelist)
{
    int level = 0;
    int n = 0;
    const char *format = *p_format;
    int i;
    Py_ssize_t len;

    for (;;) {
        int c = *format++;
        if (c == '(') {
            if (level == 0)
                n++;
            level++;
        }
        else if (c == ')') {
            if (level == 0)
                break;
            level--;
        }
        else if (c == ':' || c == ';' || c == '\0')
            break;
        else if (level == 0 && Py_ISALPHA(Py_CHARMASK(c)))
            n++;
    }

    if (!PySequence_Check(arg) || PyBytes_Check(arg)) {
        levels[0] = 0;
        PyOS_snprintf(msgbuf, bufsize,
                      toplevel ? "expected %d arguments, not %.50s" :
                      "must be %d-item sequence, not %.50s",
                  n,
                  arg == Py_None ? "None" : arg->ob_type->tp_name);
        return msgbuf;
    }

    len = PySequence_Size(arg);
    if (len != n) {
        levels[0] = 0;
        if (toplevel) {
            PyOS_snprintf(msgbuf, bufsize,
                          "expected %d arguments, not %" PY_FORMAT_SIZE_T "d",
                          n, len);
        }
        else {
            PyOS_snprintf(msgbuf, bufsize,
                          "must be sequence of length %d, "
                          "not %" PY_FORMAT_SIZE_T "d",
                          n, len);
        }
        return msgbuf;
    }

    format = *p_format;
    for (i = 0; i < n; i++) {
        const char *msg;
        PyObject *item;
        item = PySequence_GetItem(arg, i);
        if (item == NULL) {
            PyErr_Clear();
            levels[0] = i+1;
            levels[1] = 0;
            strncpy(msgbuf, "is not retrievable", bufsize);
            return msgbuf;
        }
        msg = convertitem(item, &format, p_va, flags, levels+1,
                          msgbuf, bufsize, freelist);
        /* PySequence_GetItem calls tp->sq_item, which INCREFs */
        Py_XDECREF(item);
        if (msg != NULL) {
            levels[0] = i+1;
            return msg;
        }
    }

    *p_format = format;
    return NULL;
}


/* Convert a single item. */

static const char *
convertitem(PyObject *arg, const char **p_format, va_list *p_va, int flags,
            int *levels, char *msgbuf, size_t bufsize, freelist_t *freelist)
{
    const char *msg;
    const char *format = *p_format;

    if (*format == '(' /* ')' */) {
        format++;
        msg = converttuple(arg, &format, p_va, flags, levels, msgbuf,
                           bufsize, 0, freelist);
        if (msg == NULL)
            format++;
    }
    else {
        msg = convertsimple(arg, &format, p_va, flags,
                            msgbuf, bufsize, freelist);
        if (msg != NULL)
            levels[0] = 0;
    }
    if (msg == NULL)
        *p_format = format;
    return msg;
}



/* Format an error message generated by convertsimple(). */

static const char *
converterr(const char *expected, PyObject *arg, char *msgbuf, size_t bufsize)
{
    assert(expected != NULL);
    assert(arg != NULL);
    if (expected[0] == '(') {
        PyOS_snprintf(msgbuf, bufsize,
                      "%.100s", expected);
    }
    else {
        PyOS_snprintf(msgbuf, bufsize,
                      "must be %.50s, not %.50s", expected,
                      arg == Py_None ? "None" : arg->ob_type->tp_name);
    }
    return msgbuf;
}

#define CONV_UNICODE "(unicode conversion error)"

/* Explicitly check for float arguments when integers are expected.
   Return 1 for error, 0 if ok. */
static int
float_argument_error(PyObject *arg)
{
    if (PyFloat_Check(arg)) {
        PyErr_SetString(PyExc_TypeError,
                        "integer argument expected, got float" );
        return 1;
    }
    else
        return 0;
}

/* Convert a non-tuple argument.  Return NULL if conversion went OK,
   or a string with a message describing the failure.  The message is
   formatted as "must be <desired type>, not <actual type>".
   When failing, an exception may or may not have been raised.
   Don't call if a tuple is expected.

   When you add new format codes, please don't forget poor skipitem() below.
*/

static const char *
convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
              char *msgbuf, size_t bufsize, freelist_t *freelist)
{
    /* For # codes */
#define FETCH_SIZE      int *q=NULL;Py_ssize_t *q2=NULL;\
    if (flags & FLAG_SIZE_T) q2=va_arg(*p_va, Py_ssize_t*); \
    else q=va_arg(*p_va, int*);
#define STORE_SIZE(s)   \
    if (flags & FLAG_SIZE_T) \
        *q2=s; \
    else { \
        if (INT_MAX < s) { \
            PyErr_SetString(PyExc_OverflowError, \
                "size does not fit in an int"); \
            return converterr("", arg, msgbuf, bufsize); \
        } \
        *q = (int)s; \
    }
#define BUFFER_LEN      ((flags & FLAG_SIZE_T) ? *q2:*q)
#define RETURN_ERR_OCCURRED return msgbuf

    const char *format = *p_format;
    char c = *format++;
    char *sarg;

    switch (c) {

    case 'b': { /* unsigned byte -- very short int */
        char *p = va_arg(*p_va, char *);
        long ival;
        if (float_argument_error(arg))
            RETURN_ERR_OCCURRED;
        ival = PyLong_AsLong(arg);
        if (ival == -1 && PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else if (ival < 0) {
            PyErr_SetString(PyExc_OverflowError,
                            "unsigned byte integer is less than minimum");
            RETURN_ERR_OCCURRED;
        }
        else if (ival > UCHAR_MAX) {
            PyErr_SetString(PyExc_OverflowError,
                            "unsigned byte integer is greater than maximum");
            RETURN_ERR_OCCURRED;
        }
        else
            *p = (unsigned char) ival;
        break;
    }

    case 'B': {/* byte sized bitfield - both signed and unsigned
                  values allowed */
        char *p = va_arg(*p_va, char *);
        long ival;
        if (float_argument_error(arg))
            RETURN_ERR_OCCURRED;
        ival = PyLong_AsUnsignedLongMask(arg);
        if (ival == -1 && PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else
            *p = (unsigned char) ival;
        break;
    }

    case 'h': {/* signed short int */
        short *p = va_arg(*p_va, short *);
        long ival;
        if (float_argument_error(arg))
            RETURN_ERR_OCCURRED;
        ival = PyLong_AsLong(arg);
        if (ival == -1 && PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else if (ival < SHRT_MIN) {
            PyErr_SetString(PyExc_OverflowError,
                            "signed short integer is less than minimum");
            RETURN_ERR_OCCURRED;
        }
        else if (ival > SHRT_MAX) {
            PyErr_SetString(PyExc_OverflowError,
                            "signed short integer is greater than maximum");
            RETURN_ERR_OCCURRED;
        }
        else
            *p = (short) ival;
        break;
    }

    case 'H': { /* short int sized bitfield, both signed and
                   unsigned allowed */
        unsigned short *p = va_arg(*p_va, unsigned short *);
        long ival;
        if (float_argument_error(arg))
            RETURN_ERR_OCCURRED;
        ival = PyLong_AsUnsignedLongMask(arg);
        if (ival == -1 && PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else
            *p = (unsigned short) ival;
        break;
    }

    case 'i': {/* signed int */
        int *p = va_arg(*p_va, int *);
        long ival;
        if (float_argument_error(arg))
            RETURN_ERR_OCCURRED;
        ival = PyLong_AsLong(arg);
        if (ival == -1 && PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else if (ival > INT_MAX) {
            PyErr_SetString(PyExc_OverflowError,
                            "signed integer is greater than maximum");
            RETURN_ERR_OCCURRED;
        }
        else if (ival < INT_MIN) {
            PyErr_SetString(PyExc_OverflowError,
                            "signed integer is less than minimum");
            RETURN_ERR_OCCURRED;
        }
        else
            *p = ival;
        break;
    }

    case 'I': { /* int sized bitfield, both signed and
                   unsigned allowed */
        unsigned int *p = va_arg(*p_va, unsigned int *);
        unsigned int ival;
        if (float_argument_error(arg))
            RETURN_ERR_OCCURRED;
        ival = (unsigned int)PyLong_AsUnsignedLongMask(arg);
        if (ival == (unsigned int)-1 && PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else
            *p = ival;
        break;
    }

    case 'n': /* Py_ssize_t */
    {
        PyObject *iobj;
        Py_ssize_t *p = va_arg(*p_va, Py_ssize_t *);
        Py_ssize_t ival = -1;
        if (float_argument_error(arg))
            RETURN_ERR_OCCURRED;
        iobj = PyNumber_Index(arg);
        if (iobj != NULL) {
            ival = PyLong_AsSsize_t(iobj);
            Py_DECREF(iobj);
        }
        if (ival == -1 && PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        *p = ival;
        break;
    }
    case 'l': {/* long int */
        long *p = va_arg(*p_va, long *);
        long ival;
        if (float_argument_error(arg))
            RETURN_ERR_OCCURRED;
        ival = PyLong_AsLong(arg);
        if (ival == -1 && PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else
            *p = ival;
        break;
    }

    case 'k': { /* long sized bitfield */
        unsigned long *p = va_arg(*p_va, unsigned long *);
        unsigned long ival;
        if (PyLong_Check(arg))
            ival = PyLong_AsUnsignedLongMask(arg);
        else
            return converterr("int", arg, msgbuf, bufsize);
        *p = ival;
        break;
    }

    case 'L': {/* long long */
        long long *p = va_arg( *p_va, long long * );
        long long ival;
        if (float_argument_error(arg))
            RETURN_ERR_OCCURRED;
        ival = PyLong_AsLongLong(arg);
        if (ival == (long long)-1 && PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else
            *p = ival;
        break;
    }

    case 'K': { /* long long sized bitfield */
        unsigned long long *p = va_arg(*p_va, unsigned long long *);
        unsigned long long ival;
        if (PyLong_Check(arg))
            ival = PyLong_AsUnsignedLongLongMask(arg);
        else
            return converterr("int", arg, msgbuf, bufsize);
        *p = ival;
        break;
    }

    case 'f': {/* float */
        float *p = va_arg(*p_va, float *);
        double dval = PyFloat_AsDouble(arg);
        if (PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else
            *p = (float) dval;
        break;
    }

    case 'd': {/* double */
        double *p = va_arg(*p_va, double *);
        double dval = PyFloat_AsDouble(arg);
        if (PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else
            *p = dval;
        break;
    }

    case 'D': {/* complex double */
        Py_complex *p = va_arg(*p_va, Py_complex *);
        Py_complex cval;
        cval = PyComplex_AsCComplex(arg);
        if (PyErr_Occurred())
            RETURN_ERR_OCCURRED;
        else
            *p = cval;
        break;
    }

    case 'c': {/* char */
        char *p = va_arg(*p_va, char *);
        if (PyBytes_Check(arg) && PyBytes_Size(arg) == 1)
            *p = PyBytes_AS_STRING(arg)[0];
        else if (PyByteArray_Check(arg) && PyByteArray_Size(arg) == 1)
            *p = PyByteArray_AS_STRING(arg)[0];
        else
            return converterr("a byte string of length 1", arg, msgbuf, bufsize);
        break;
    }

    case 'C': {/* unicode char */
        int *p = va_arg(*p_va, int *);
        int kind;
        void *data;

        if (!PyUnicode_Check(arg))
            return converterr("a unicode character", arg, msgbuf, bufsize);

        if (PyUnicode_READY(arg))
            RETURN_ERR_OCCURRED;

        if (PyUnicode_GET_LENGTH(arg) != 1)
            return converterr("a unicode character", arg, msgbuf, bufsize);

        kind = PyUnicode_KIND(arg);
        data = PyUnicode_DATA(arg);
        *p = PyUnicode_READ(kind, data, 0);
        break;
    }

    case 'p': {/* boolean *p*redicate */
        int *p = va_arg(*p_va, int *);
        int val = PyObject_IsTrue(arg);
        if (val > 0)
            *p = 1;
        else if (val == 0)
            *p = 0;
        else
            RETURN_ERR_OCCURRED;
        break;
    }

    /* XXX WAAAAH!  's', 'y', 'z', 'u', 'Z', 'e', 'w' codes all
       need to be cleaned up! */

    case 'y': {/* any bytes-like object */
        void **p = (void **)va_arg(*p_va, char **);
        const char *buf;
        Py_ssize_t count;
        if (*format == '*') {
            if (getbuffer(arg, (Py_buffer*)p, &buf) < 0)
                return converterr(buf, arg, msgbuf, bufsize);
            format++;
            if (addcleanup(p, freelist, cleanup_buffer)) {
                return converterr(
                    "(cleanup problem)",
                    arg, msgbuf, bufsize);
            }
            break;
        }
        count = convertbuffer(arg, p, &buf);
        if (count < 0)
            return converterr(buf, arg, msgbuf, bufsize);
        if (*format == '#') {
            FETCH_SIZE;
            STORE_SIZE(count);
            format++;
        } else {
            if (strlen(*p) != (size_t)count) {
                PyErr_SetString(PyExc_ValueError, "embedded null byte");
                RETURN_ERR_OCCURRED;
            }
        }
        break;
    }

    case 's': /* text string or bytes-like object */
    case 'z': /* text string, bytes-like object or None */
    {
        if (*format == '*') {
            /* "s*" or "z*" */
            Py_buffer *p = (Py_buffer *)va_arg(*p_va, Py_buffer *);

            if (c == 'z' && arg == Py_None)
                PyBuffer_FillInfo(p, NULL, NULL, 0, 1, 0);
            else if (PyUnicode_Check(arg)) {
                Py_ssize_t len;
                sarg = PyUnicode_AsUTF8AndSize(arg, &len);
                if (sarg == NULL)
                    return converterr(CONV_UNICODE,
                                      arg, msgbuf, bufsize);
                PyBuffer_FillInfo(p, arg, sarg, len, 1, 0);
            }
            else { /* any bytes-like object */
                const char *buf;
                if (getbuffer(arg, p, &buf) < 0)
                    return converterr(buf, arg, msgbuf, bufsize);
            }
            if (addcleanup(p, freelist, cleanup_buffer)) {
                return converterr(
                    "(cleanup problem)",
                    arg, msgbuf, bufsize);
            }
            format++;
        } else if (*format == '#') { /* a string or read-only bytes-like object */
            /* "s#" or "z#" */
            void **p = (void **)va_arg(*p_va, char **);
            FETCH_SIZE;

            if (c == 'z' && arg == Py_None) {
                *p = NULL;
                STORE_SIZE(0);
            }
            else if (PyUnicode_Check(arg)) {
                Py_ssize_t len;
                sarg = PyUnicode_AsUTF8AndSize(arg, &len);
                if (sarg == NULL)
                    return converterr(CONV_UNICODE,
                                      arg, msgbuf, bufsize);
                *p = sarg;
                STORE_SIZE(len);
            }
            else { /* read-only bytes-like object */
                /* XXX Really? */
                const char *buf;
                Py_ssize_t count = convertbuffer(arg, p, &buf);
                if (count < 0)
                    return converterr(buf, arg, msgbuf, bufsize);
                STORE_SIZE(count);
            }
            format++;
        } else {
            /* "s" or "z" */
            char **p = va_arg(*p_va, char **);
            Py_ssize_t len;
            sarg = NULL;

            if (c == 'z' && arg == Py_None)
                *p = NULL;
            else if (PyUnicode_Check(arg)) {
                sarg = PyUnicode_AsUTF8AndSize(arg, &len);
                if (sarg == NULL)
                    return converterr(CONV_UNICODE,
                                      arg, msgbuf, bufsize);
                if (strlen(sarg) != (size_t)len) {
                    PyErr_SetString(PyExc_ValueError, "embedded null character");
                    RETURN_ERR_OCCURRED;
                }
                *p = sarg;
            }
            else
                return converterr(c == 'z' ? "str or None" : "str",
                                  arg, msgbuf, bufsize);
        }
        break;
    }

    case 'u': /* raw unicode buffer (Py_UNICODE *) */
    case 'Z': /* raw unicode buffer or None */
    {