/* struct module -- pack values into and (out of) bytes objects */

/* New version supporting byte order, alignment and size options,
   character strings, and unsigned numbers */

#define PY_SSIZE_T_CLEAN

#include "Python.h"
#include "structmember.h"         // PyMemberDef
#include 

/*[clinic input]
class Struct "PyStructObject *" "&PyStructType"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=9b032058a83ed7c3]*/

typedef struct {
    PyObject *PyStructType;
    PyObject *unpackiter_type;
    PyObject *StructError;
} _structmodulestate;

static inline _structmodulestate*
get_struct_state(PyObject *module)
{
    void *state = PyModule_GetState(module);
    assert(state != NULL);
    return (_structmodulestate *)state;
}

static struct PyModuleDef _structmodule;

#define _structmodulestate_global get_struct_state(PyState_FindModule(&_structmodule))

/* The translation function for each format character is table driven */
typedef struct _formatdef {
    char format;
    Py_ssize_t size;
    Py_ssize_t alignment;
    PyObject* (*unpack)(const char *,
                        const struct _formatdef *);
    int (*pack)(char *, PyObject *,
                const struct _formatdef *);
} formatdef;

typedef struct _formatcode {
    const struct _formatdef *fmtdef;
    Py_ssize_t offset;
    Py_ssize_t size;
    Py_ssize_t repeat;
} formatcode;

/* Struct object interface */

typedef struct {
    PyObject_HEAD
    Py_ssize_t s_size;
    Py_ssize_t s_len;
    formatcode *s_codes;
    PyObject *s_format;
    PyObject *weakreflist; /* List of weak references */
} PyStructObject;


#define PyStruct_Check(op) PyObject_TypeCheck(op, (PyTypeObject *)_structmodulestate_global->PyStructType)
#define PyStruct_CheckExact(op) Py_IS_TYPE(op, (PyTypeObject *)_structmodulestate_global->PyStructType)


/* Define various structs to figure out the alignments of types */


typedef struct { char c; short x; } st_short;
typedef struct { char c; int x; } st_int;
typedef struct { char c; long x; } st_long;
typedef struct { char c; float x; } st_float;
typedef struct { char c; double x; } st_double;
typedef struct { char c; void *x; } st_void_p;
typedef struct { char c; size_t x; } st_size_t;
typedef struct { char c; _Bool x; } st_bool;

#define SHORT_ALIGN (sizeof(st_short) - sizeof(short))
#define INT_ALIGN (sizeof(st_int) - sizeof(int))
#define LONG_ALIGN (sizeof(st_long) - sizeof(long))
#define FLOAT_ALIGN (sizeof(st_float) - sizeof(float))
#define DOUBLE_ALIGN (sizeof(st_double) - sizeof(double))
#define VOID_P_ALIGN (sizeof(st_void_p) - sizeof(void *))
#define SIZE_T_ALIGN (sizeof(st_size_t) - sizeof(size_t))
#define BOOL_ALIGN (sizeof(st_bool) - sizeof(_Bool))

/* We can't support q and Q in native mode unless the compiler does;
   in std mode, they're 8 bytes on all platforms. */
typedef struct { char c; long long x; } s_long_long;
#define LONG_LONG_ALIGN (sizeof(s_long_long) - sizeof(long long))

#ifdef __powerc
#pragma options align=reset
#endif

/*[python input]
class cache_struct_converter(CConverter):
    type = 'PyStructObject *'
    converter = 'cache_struct_converter'
    c_default = "NULL"

    def cleanup(self):
        return "Py_XDECREF(%s);\n" % self.name
[python start generated code]*/
/*[python end generated code: output=da39a3ee5e6b4b0d input=49957cca130ffb63]*/

static int cache_struct_converter(PyObject *, PyStructObject **);

#include "clinic/_struct.c.h"

/* Helper for integer format codes: converts an arbitrary Python object to a
   PyLongObject if possible, otherwise fails.  Caller should decref. */

static PyObject *
get_pylong(PyObject *v)
{
    assert(v != NULL);
    if (!PyLong_Check(v)) {
        /* Not an integer;  try to use __index__ to convert. */
        if (PyIndex_Check(v)) {
            v = _PyNumber_Index(v);
            if (v == NULL)
                return NULL;
        }
        else {
            PyErr_SetString(_structmodulestate_global->StructError,
                            "required argument is not an integer");
            return NULL;
        }
    }
    else
        Py_INCREF(v);

    assert(PyLong_Check(v));
    return v;
}

/* Helper routine to get a C long and raise the appropriate error if it isn't
   one */

static int
get_long(PyObject *v, long *p)
{
    long x;

    v = get_pylong(v);
    if (v == NULL)
        return -1;
    assert(PyLong_Check(v));
    x = PyLong_AsLong(v);
    Py_DECREF(v);
    if (x == (long)-1 && PyErr_Occurred()) {
        if (PyErr_ExceptionMatches(PyExc_OverflowError))
            PyErr_SetString(_structmodulestate_global->StructError,
                            "argument out of range");
        return -1;
    }
    *p = x;
    return 0;
}


/* Same, but handling unsigned long */

static int
get_ulong(PyObject *v, unsigned long *p)
{
    unsigned long x;

    v = get_pylong(v);
    if (v == NULL)
        return -1;
    assert(PyLong_Check(v));
    x = PyLong_AsUnsignedLong(v);
    Py_DECREF(v);
    if (x == (unsigned long)-1 && PyErr_Occurred()) {
        if (PyErr_ExceptionMatches(PyExc_OverflowError))
            PyErr_SetString(_structmodulestate_global->StructError,
                            "argument out of range");
        return -1;
    }
    *p = x;
    return 0;
}

/* Same, but handling native long long. */

static int
get_longlong(PyObject *v, long long *p)
{
    long long x;

    v = get_pylong(v);
    if (v == NULL)
        return -1;
    assert(PyLong_Check(v));
    x = PyLong_AsLongLong(v);
    Py_DECREF(v);
    if (x == (long long)-1 && PyErr_Occurred()) {
        if (PyErr_ExceptionMatches(PyExc_OverflowError))
            PyErr_SetString(_structmodulestate_global->StructError,
                            "argument out of range");
        return -1;
    }
    *p = x;
    return 0;
}

/* Same, but handling native unsigned long long. */

static int
get_ulonglong(PyObject *v, unsigned long long *p)
{
    unsigned long long x;

    v = get_pylong(v);
    if (v == NULL)
        return -1;
    assert(PyLong_Check(v));
    x = PyLong_AsUnsignedLongLong(v);
    Py_DECREF(v);
    if (x == (unsigned long long)-1 && PyErr_Occurred()) {
        if (PyErr_ExceptionMatches(PyExc_OverflowError))
            PyErr_SetString(_structmodulestate_global->StructError,
                            "argument out of range");
        return -1;
    }
    *p = x;
    return 0;
}

/* Same, but handling Py_ssize_t */

static int
get_ssize_t(PyObject *v, Py_ssize_t *p)
{
    Py_ssize_t x;

    v = get_pylong(v);
    if (v == NULL)
        return -1;
    assert(PyLong_Check(v));
    x = PyLong_AsSsize_t(v);
    Py_DECREF(v);
    if (x == (Py_ssize_t)-1 && PyErr_Occurred()) {
        if (PyErr_ExceptionMatches(PyExc_OverflowError))
            PyErr_SetString(_structmodulestate_global->StructError,
                            "argument out of range");
        return -1;
    }
    *p = x;
    return 0;
}

/* Same, but handling size_t */

static int
get_size_t(PyObject *v, size_t *p)
{
    size_t x;

    v = get_pylong(v);
    if (v == NULL)
        return -1;
    assert(PyLong_Check(v));
    x = PyLong_AsSize_t(v);
    Py_DECREF(v);
    if (x == (size_t)-1 && PyErr_Occurred()) {
        if (PyErr_ExceptionMatches(PyExc_OverflowError))
            PyErr_SetString(_structmodulestate_global->StructError,
                            "argument out of range");
        return -1;
    }
    *p = x;
    return 0;
}


#define RANGE_ERROR(x, f, flag, mask) return _range_error(f, flag)


/* Floating point helpers */

static PyObject *
unpack_halffloat(const char *p,  /* start of 2-byte string */
                 int le)         /* true for little-endian, false for big-endian */
{
    double x;

    x = _PyFloat_Unpack2((unsigned char *)p, le);
    if (x == -1.0 && PyErr_Occurred()) {
        return NULL;
    }
    return PyFloat_FromDouble(x);
}

static int
pack_halffloat(char *p,      /* start of 2-byte string */
               PyObject *v,  /* value to pack */
               int le)       /* true for little-endian, false for big-endian */
{
    double x = PyFloat_AsDouble(v);
    if (x == -1.0 && PyErr_Occurred()) {
        PyErr_SetString(_structmodulestate_global->StructError,
                        "required argument is not a float");
        return -1;
    }
    return _PyFloat_Pack2(x, (unsigned char *)p, le);
}

static PyObject *
unpack_float(const char *p,  /* start of 4-byte string */
         int le)             /* true for little-endian, false for big-endian */
{
    double x;

    x = _PyFloat_Unpack4((unsigned char *)p, le);
    if (x == -1.0 && PyErr_Occurred())
        return NULL;
    return PyFloat_FromDouble(x);
}

static PyObject *
unpack_double(const char *p,  /* start of 8-byte string */
          int le)         /* true for little-endian, false for big-endian */
{
    double x;

    x = _PyFloat_Unpack8((unsigned char *)p, le);
    if (x == -1.0 && PyErr_Occurred())
        return NULL;
    return PyFloat_FromDouble(x);
}

/* Helper to format the range error exceptions */
static int
_range_error(const formatdef *f, int is_unsigned)
{
    /* ulargest is the largest unsigned value with f->size bytes.
     * Note that the simpler:
     *     ((size_t)1 size * 8)) - 1
     * doesn't work when f->size == sizeof(size_t) because C doesn't
     * define what happens when a left shift count is >= the number of
     * bits in the integer being shifted; e.g., on some boxes it doesn't
     * shift at all when they're equal.
     */
    const size_t ulargest = (size_t)-1 >> ((SIZEOF_SIZE_T - f->size)*8);
    assert(f->size >= 1 && f->size StructError,
            "'%c' format requires 0