_decimal.c

/*
 * Copyright (c) 2008-2012 Stefan Krah. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */


#include <Python.h>
#include "longintrepr.h"
#include "pythread.h"
#include "structmember.h"
#include "complexobject.h"
#include "mpdecimal.h"

#include <stdlib.h>

#include "docstrings.h"
#include "memory.h"


#if MPD_MAJOR_VERSION != 2
  #error "libmpdec major version 2 required"
#endif


/*
 * Type sizes with assertions in mpdecimal.h and pyport.h:
 *    sizeof(size_t) == sizeof(Py_ssize_t)
 *    sizeof(size_t) == sizeof(mpd_uint_t) == sizeof(mpd_ssize_t)
 */

#ifdef TEST_COVERAGE
  #undef Py_LOCAL_INLINE
  #define Py_LOCAL_INLINE Py_LOCAL
#endif

#define MPD_Float_operation MPD_Not_implemented

#define BOUNDS_CHECK(x, MIN, MAX) x = (x < MIN || MAX < x) ? MAX : x


/* _Py_DEC_MINALLOC >= MPD_MINALLOC */
#define _Py_DEC_MINALLOC 4

typedef struct {
    PyObject_HEAD
    Py_hash_t hash;
    mpd_t dec;
    mpd_uint_t data[_Py_DEC_MINALLOC];
} PyDecObject;

typedef struct {
    PyObject_HEAD
    uint32_t *flags;
} PyDecSignalDictObject;

typedef struct {
    PyObject_HEAD
    mpd_context_t ctx;
    PyObject *traps;
    PyObject *flags;
    int capitals;
#ifndef WITHOUT_THREADS
    PyThreadState *tstate;
#endif
} PyDecContextObject;

typedef struct {
    PyObject_HEAD
    PyObject *local;
    PyObject *global;
} PyDecContextManagerObject;


#undef MPD
#undef CTX
static PyTypeObject PyDec_Type;
static PyTypeObject *PyDecSignalDict_Type;
static PyTypeObject PyDecContext_Type;
static PyTypeObject PyDecContextManager_Type;
#define PyDec_CheckExact(v) (Py_TYPE(v) == &PyDec_Type)
#define PyDec_Check(v) PyObject_TypeCheck(v, &PyDec_Type)
#define PyDecSignalDict_Check(v) (Py_TYPE(v) == PyDecSignalDict_Type)
#define PyDecContext_Check(v) PyObject_TypeCheck(v, &PyDecContext_Type)
#define MPD(v) (&((PyDecObject *)v)->dec)
#define SdFlagAddr(v) (((PyDecSignalDictObject *)v)->flags)
#define SdFlags(v) (*((PyDecSignalDictObject *)v)->flags)
#define CTX(v) (&((PyDecContextObject *)v)->ctx)
#define CtxCaps(v) (((PyDecContextObject *)v)->capitals)


Py_LOCAL_INLINE(PyObject *)
incr_true(void)
{
    Py_INCREF(Py_True);
    return Py_True;
}

Py_LOCAL_INLINE(PyObject *)
incr_false(void)
{
    Py_INCREF(Py_False);
    return Py_False;
}


#ifdef WITHOUT_THREADS
/* Default module context */
static PyObject *module_context = NULL;
#else
/* Key for thread state dictionary */
static PyObject *tls_context_key = NULL;
/* Invariant: NULL or the most recently accessed thread local context */
static PyDecContextObject *cached_context = NULL;
#endif

/* Template for creating new thread contexts, calling Context() without
 * arguments and initializing the module_context on first access. */
static PyObject *default_context_template = NULL;
/* Basic and extended context templates */
static PyObject *basic_context_template = NULL;
static PyObject *extended_context_template = NULL;


/* Error codes for functions that return signals or conditions */
#define DEC_INVALID_SIGNALS (MPD_Max_status+1U)
#define DEC_ERR_OCCURRED (DEC_INVALID_SIGNALS<<1)
#define DEC_ERRORS (DEC_INVALID_SIGNALS|DEC_ERR_OCCURRED)

typedef struct {
    const char *name;   /* condition or signal name */
    const char *fqname; /* fully qualified name */
    uint32_t flag;      /* libmpdec flag */
    PyObject *ex;       /* corresponding exception */
} DecCondMap;

/* Top level Exception; inherits from ArithmeticError */
static PyObject *DecimalException = NULL;

/* Exceptions that correspond to IEEE signals */
#define SUBNORMAL 5
#define INEXACT 6
#define ROUNDED 7
#define SIGNAL_MAP_LEN 9
static DecCondMap signal_map[] = {
  {"InvalidOperation", "decimal.InvalidOperation", MPD_IEEE_Invalid_operation, NULL},
  {"FloatOperation", "decimal.FloatOperation", MPD_Float_operation, NULL},
  {"DivisionByZero", "decimal.DivisionByZero", MPD_Division_by_zero, NULL},
  {"Overflow", "decimal.Overflow", MPD_Overflow, NULL},
  {"Underflow", "decimal.Underflow", MPD_Underflow, NULL},
  {"Subnormal", "decimal.Subnormal", MPD_Subnormal, NULL},
  {"Inexact", "decimal.Inexact", MPD_Inexact, NULL},
  {"Rounded", "decimal.Rounded", MPD_Rounded, NULL},
  {"Clamped", "decimal.Clamped", MPD_Clamped, NULL},
  {NULL}
};

/* Exceptions that inherit from InvalidOperation */
static DecCondMap cond_map[] = {
  {"InvalidOperation", "decimal.InvalidOperation", MPD_Invalid_operation, NULL},
  {"ConversionSyntax", "decimal.ConversionSyntax", MPD_Conversion_syntax, NULL},
  {"DivisionImpossible", "decimal.DivisionImpossible", MPD_Division_impossible, NULL},
  {"DivisionUndefined", "decimal.DivisionUndefined", MPD_Division_undefined, NULL},
  {"InvalidContext", "decimal.InvalidContext", MPD_Invalid_context, NULL},
#ifdef EXTRA_FUNCTIONALITY
  {"MallocError", "decimal.MallocError", MPD_Malloc_error, NULL},
#endif
  {NULL}
};

static const char *dec_signal_string[MPD_NUM_FLAGS] = {
    "Clamped",
    "InvalidOperation",
    "DivisionByZero",
    "InvalidOperation",
    "InvalidOperation",
    "InvalidOperation",
    "Inexact",
    "InvalidOperation",
    "InvalidOperation",
    "InvalidOperation",
    "FloatOperation",
    "Overflow",
    "Rounded",
    "Subnormal",
    "Underflow",
};

#ifdef EXTRA_FUNCTIONALITY
  #define _PY_DEC_ROUND_GUARD MPD_ROUND_GUARD
#else
  #define _PY_DEC_ROUND_GUARD (MPD_ROUND_GUARD-1)
#endif
static PyObject *round_map[_PY_DEC_ROUND_GUARD];

static const char *invalid_rounding_err =
"valid values for rounding are:\n\
  [ROUND_CEILING, ROUND_FLOOR, ROUND_UP, ROUND_DOWN,\n\
   ROUND_HALF_UP, ROUND_HALF_DOWN, ROUND_HALF_EVEN,\n\
   ROUND_05UP]";

static const char *invalid_signals_err =
"valid values for signals are:\n\
  [InvalidOperation, FloatOperation, DivisionByZero,\n\
   Overflow, Underflow, Subnormal, Inexact, Rounded,\n\
   Clamped]";

#ifdef EXTRA_FUNCTIONALITY
static const char *invalid_flags_err =
"valid values for _flags or _traps are:\n\
  signals:\n\
    [DecIEEEInvalidOperation, DecFloatOperation, DecDivisionByZero,\n\
     DecOverflow, DecUnderflow, DecSubnormal, DecInexact, DecRounded,\n\
     DecClamped]\n\
  conditions which trigger DecIEEEInvalidOperation:\n\
    [DecInvalidOperation, DecConversionSyntax, DecDivisionImpossible,\n\
     DecDivisionUndefined, DecFpuError, DecInvalidContext, DecMallocError]";
#endif

static int
value_error_int(const char *mesg)
{
    PyErr_SetString(PyExc_ValueError, mesg);
    return -1;
}

#ifdef CONFIG_32
static PyObject *
value_error_ptr(const char *mesg)
{
    PyErr_SetString(PyExc_ValueError, mesg);
    return NULL;
}
#endif

static int
type_error_int(const char *mesg)
{
    PyErr_SetString(PyExc_TypeError, mesg);
    return -1;
}

static int
runtime_error_int(const char *mesg)
{
    PyErr_SetString(PyExc_RuntimeError, mesg);
    return -1;
}
#define INTERNAL_ERROR_INT(funcname) \
    return runtime_error_int("internal error in " funcname)

static PyObject *
runtime_error_ptr(const char *mesg)
{
    PyErr_SetString(PyExc_RuntimeError, mesg);
    return NULL;
}
#define INTERNAL_ERROR_PTR(funcname) \
    return runtime_error_ptr("internal error in " funcname)

static void
dec_traphandler(mpd_context_t *ctx UNUSED) /* GCOV_NOT_REACHED */
{ /* GCOV_NOT_REACHED */
    return; /* GCOV_NOT_REACHED */
}

static PyObject *
flags_as_exception(uint32_t flags)
{
    DecCondMap *cm;

    for (cm = signal_map; cm->name != NULL; cm++) {
        if (flags&cm->flag) {
            return cm->ex;
        }
    }

    INTERNAL_ERROR_PTR("flags_as_exception"); /* GCOV_NOT_REACHED */
}

Py_LOCAL_INLINE(uint32_t)
exception_as_flag(PyObject *ex)
{
    DecCondMap *cm;

    for (cm = signal_map; cm->name != NULL; cm++) {
        if (cm->ex == ex) {
            return cm->flag;
        }
    }

    PyErr_SetString(PyExc_KeyError, invalid_signals_err);
    return DEC_INVALID_SIGNALS;
}

static PyObject *
flags_as_list(uint32_t flags)
{
    PyObject *list;
    DecCondMap *cm;

    list = PyList_New(0);
    if (list == NULL) {
        return NULL;
    }

    for (cm = cond_map; cm->name != NULL; cm++) {
        if (flags&cm->flag) {
            if (PyList_Append(list, cm->ex) < 0) {
                goto error;
            }
        }
    }
    for (cm = signal_map+1; cm->name != NULL; cm++) {
        if (flags&cm->flag) {
            if (PyList_Append(list, cm->ex) < 0) {
                goto error;
            }
        }
    }

    return list;

error:
    Py_DECREF(list);
    return NULL;
}

static PyObject *
signals_as_list(uint32_t flags)
{
    PyObject *list;
    DecCondMap *cm;

    list = PyList_New(0);
    if (list == NULL) {
        return NULL;
    }

    for (cm = signal_map; cm->name != NULL; cm++) {
        if (flags&cm->flag) {
            if (PyList_Append(list, cm->ex) < 0) {
                Py_DECREF(list);
                return NULL;
            }
        }
    }

    return list;
}

static uint32_t
list_as_flags(PyObject *list)
{
    PyObject *item;
    uint32_t flags, x;
    Py_ssize_t n, j;

    assert(PyList_Check(list));

    n = PyList_Size(list);
    flags = 0;
    for (j = 0; j < n; j++) {
        item = PyList_GetItem(list, j);
        x = exception_as_flag(item);
        if (x & DEC_ERRORS) {
            return x;
        }
        flags |= x;
    }

    return flags;
}

static PyObject *
flags_as_dict(uint32_t flags)
{
    DecCondMap *cm;
    PyObject *dict;

    dict = PyDict_New();
    if (dict == NULL) {
        return NULL;
    }

    for (cm = signal_map; cm->name != NULL; cm++) {
        PyObject *b = flags&cm->flag ? Py_True : Py_False;
        if (PyDict_SetItem(dict, cm->ex, b) < 0) {
            Py_DECREF(dict);
            return NULL;
        }
    }

    return dict;
}

static uint32_t
dict_as_flags(PyObject *val)
{
    PyObject *b;
    DecCondMap *cm;
    uint32_t flags = 0;
    int x;

    if (!PyDict_Check(val)) {
        PyErr_SetString(PyExc_TypeError,
            "argument must be a signal dict");
        return DEC_INVALID_SIGNALS;
    }

    if (PyDict_Size(val) != SIGNAL_MAP_LEN) {
        PyErr_SetString(PyExc_KeyError,
            "invalid signal dict");
        return DEC_INVALID_SIGNALS;
    }

    for (cm = signal_map; cm->name != NULL; cm++) {
        b = PyDict_GetItemWithError(val, cm->ex);
        if (b == NULL) {
            if (PyErr_Occurred()) {
                return DEC_ERR_OCCURRED;
            }
            PyErr_SetString(PyExc_KeyError,
                "invalid signal dict");
            return DEC_INVALID_SIGNALS;
        }

        x = PyObject_IsTrue(b);
        if (x < 0) {
            return DEC_ERR_OCCURRED;
        }
        if (x == 1) {
            flags |= cm->flag;
        }
    }

    return flags;
}

#ifdef EXTRA_FUNCTIONALITY
static uint32_t
long_as_flags(PyObject *v)
{
    long x;

    x = PyLong_AsLong(v);
    if (x == -1 && PyErr_Occurred()) {
        return DEC_ERR_OCCURRED;
    }
    if (x < 0 || x > (long)MPD_Max_status) {
        PyErr_SetString(PyExc_TypeError, invalid_flags_err);
        return DEC_INVALID_SIGNALS;
    }

    return x;
}
#endif

static int
dec_addstatus(PyObject *context, uint32_t status)
{
    mpd_context_t *ctx = CTX(context);

    ctx->status |= status;
    if (status & (ctx->traps|MPD_Malloc_error)) {
        PyObject *ex, *siglist;

        if (status & MPD_Malloc_error) {
            PyErr_NoMemory();
            return 1;
        }

        ex = flags_as_exception(ctx->traps&status);
        if (ex == NULL) {
            return 1; /* GCOV_NOT_REACHED */
        }
        siglist = flags_as_list(ctx->traps&status);
        if (siglist == NULL) {
            return 1;
        }

        PyErr_SetObject(ex, siglist);
        Py_DECREF(siglist);
        return 1;
    }
    return 0;
}

static int
getround(PyObject *v)
{
    int i;

    if (PyUnicode_Check(v)) {
        for (i = 0; i < _PY_DEC_ROUND_GUARD; i++) {
            if (v == round_map[i]) {
                return i;
            }
        }
        for (i = 0; i < _PY_DEC_ROUND_GUARD; i++) {
            if (PyUnicode_Compare(v, round_map[i]) == 0) {
                return i;
            }
        }
    }

    return type_error_int(invalid_rounding_err);
}


/******************************************************************************/
/*                            SignalDict Object                               */
/******************************************************************************/

/* The SignalDict is a MutableMapping that provides access to the
   mpd_context_t flags, which reside in the context object. When a
   new context is created, context.traps and context.flags are
   initialized to new SignalDicts. Once a SignalDict is tied to
   a context, it cannot be deleted. */

static int
signaldict_init(PyObject *self, PyObject *args UNUSED, PyObject *kwds UNUSED)
{
    SdFlagAddr(self) = NULL;
    return 0;
}

static Py_ssize_t
signaldict_len(PyObject *self UNUSED)
{
    return SIGNAL_MAP_LEN;
}

static PyObject *SignalTuple;
static PyObject *
signaldict_iter(PyObject *self UNUSED)
{
    return PyTuple_Type.tp_iter(SignalTuple);
}

static PyObject *
signaldict_getitem(PyObject *self, PyObject *key)
{
    uint32_t flag;

    flag = exception_as_flag(key);
    if (flag & DEC_ERRORS) {
        return NULL;
    }

    return SdFlags(self)&flag ? incr_true() : incr_false();
}

static int
signaldict_setitem(PyObject *self, PyObject *key, PyObject *value)
{
    uint32_t flag;
    int x;

    if (value == NULL) {
        return value_error_int("signal keys cannot be deleted");
    }

    flag = exception_as_flag(key);
    if (flag & DEC_ERRORS) {
        return -1;
    }

    x = PyObject_IsTrue(value);
    if (x < 0) {
        return -1;
    }

    if (x == 1) {
        SdFlags(self) |= flag;
    }
    else {
        SdFlags(self) &= ~flag;
    }

    return 0;
}

static PyObject *
signaldict_repr(PyObject *self)
{
    DecCondMap *cm;
    const char *n[SIGNAL_MAP_LEN]; /* name */
    const char *b[SIGNAL_MAP_LEN]; /* bool */
    int i;

    assert(SIGNAL_MAP_LEN == 9);

    for (cm=signal_map, i=0; cm->name != NULL; cm++, i++) {
        n[i] = cm->fqname;
        b[i] = SdFlags(self)&cm->flag ? "True" : "False";
    }
    return PyUnicode_FromFormat(
        "{<class '%s'>:%s, <class '%s'>:%s, <class '%s'>:%s, "
         "<class '%s'>:%s, <class '%s'>:%s, <class '%s'>:%s, "
         "<class '%s'>:%s, <class '%s'>:%s, <class '%s'>:%s}",
            n[0], b[0], n[1], b[1], n[2], b[2],
            n[3], b[3], n[4], b[4], n[5], b[5],
            n[6], b[6], n[7], b[7], n[8], b[8]);
}

static PyObject *
signaldict_richcompare(PyObject *v, PyObject *w, int op)
{
    PyObject *res = Py_NotImplemented;

    assert(PyDecSignalDict_Check(v));

    if (op == Py_EQ || op == Py_NE) {
        if (PyDecSignalDict_Check(w)) {
            res = (SdFlags(v)==SdFlags(w)) ^ (op==Py_NE) ? Py_True : Py_False;
        }
        else if (PyDict_Check(w)) {
            uint32_t flags = dict_as_flags(w);
            if (flags & DEC_ERRORS) {
                if (flags & DEC_INVALID_SIGNALS) {
                    /* non-comparable: Py_NotImplemented */
                    PyErr_Clear();
                }
                else {
                    return NULL;
                }
            }
            else {
                res = (SdFlags(v)==flags) ^ (op==Py_NE) ? Py_True : Py_False;
            }
        }
    }

    Py_INCREF(res);
    return res;
}

static PyObject *
signaldict_copy(PyObject *self, PyObject *args UNUSED)
{
    return flags_as_dict(SdFlags(self));
}


static PyMappingMethods signaldict_as_mapping = {
    (lenfunc)signaldict_len,          /* mp_length */
    (binaryfunc)signaldict_getitem,   /* mp_subscript */
    (objobjargproc)signaldict_setitem /* mp_ass_subscript */
};

static PyMethodDef signaldict_methods[] = {
    { "copy", (PyCFunction)signaldict_copy, METH_NOARGS, NULL},
    {NULL, NULL}
};


static PyTypeObject PyDecSignalDictMixin_Type =
{
    PyVarObject_HEAD_INIT(0, 0)
    "decimal.SignalDictMixin",                /* tp_name */
    sizeof(PyDecSignalDictObject),            /* tp_basicsize */
    0,                                        /* tp_itemsize */
    0,                                        /* tp_dealloc */
    0,                                        /* tp_print */
    (getattrfunc) 0,                          /* tp_getattr */
    (setattrfunc) 0,                          /* tp_setattr */
    0,                                        /* tp_reserved */
    (reprfunc) signaldict_repr,               /* tp_repr */
    0,                                        /* tp_as_number */
    0,                                        /* tp_as_sequence */
    &signaldict_as_mapping,                   /* tp_as_mapping */
    PyObject_HashNotImplemented,              /* tp_hash */
    0,                                        /* tp_call */
    (reprfunc) 0,                             /* tp_str */
    PyObject_GenericGetAttr,                  /* tp_getattro */
    (setattrofunc) 0,                         /* tp_setattro */
    (PyBufferProcs *) 0,                      /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE|
    Py_TPFLAGS_HAVE_GC,                       /* tp_flags */
    0,                                        /* tp_doc */
    0,                                        /* tp_traverse */
    0,                                        /* tp_clear */
    signaldict_richcompare,                   /* tp_richcompare */
    0,                                        /* tp_weaklistoffset */
    (getiterfunc)signaldict_iter,             /* tp_iter */
    0,                                        /* tp_iternext */
    signaldict_methods,                       /* tp_methods */
    0,                                        /* tp_members */
    0,                                        /* tp_getset */
    0,                                        /* tp_base */
    0,                                        /* tp_dict */
    0,                                        /* tp_descr_get */
    0,                                        /* tp_descr_set */
    0,                                        /* tp_dictoffset */
    (initproc)signaldict_init,                /* tp_init */
    0,                                        /* tp_alloc */
    PyType_GenericNew,                        /* tp_new */
};


/******************************************************************************/
/*                         Context Object, Part 1                             */
/******************************************************************************/

#define Dec_CONTEXT_GET_SSIZE(mem) \
static PyObject *                                       \
context_get##mem(PyObject *self, void *closure UNUSED)  \
{                                                       \
    return PyLong_FromSsize_t(mpd_get##mem(CTX(self))); \
}

#define Dec_CONTEXT_GET_ULONG(mem) \
static PyObject *                                            \
context_get##mem(PyObject *self, void *closure UNUSED)       \
{                                                            \
    return PyLong_FromUnsignedLong(mpd_get##mem(CTX(self))); \
}

Dec_CONTEXT_GET_SSIZE(prec)
Dec_CONTEXT_GET_SSIZE(emax)
Dec_CONTEXT_GET_SSIZE(emin)
Dec_CONTEXT_GET_SSIZE(clamp)

#ifdef EXTRA_FUNCTIONALITY
Dec_CONTEXT_GET_ULONG(traps)
Dec_CONTEXT_GET_ULONG(status)
#endif

static PyObject *
context_getround(PyObject *self, void *closure UNUSED)
{
    int i = mpd_getround(CTX(self));

    Py_INCREF(round_map[i]);
    return round_map[i];
}

static PyObject *
context_getcapitals(PyObject *self, void *closure UNUSED)
{
    return PyLong_FromLong(CtxCaps(self));
}

#ifdef EXTRA_FUNCTIONALITY
static PyObject *
context_getallcr(PyObject *self, void *closure UNUSED)
{
    return PyLong_FromLong(mpd_getcr(CTX(self)));
}
#endif

static PyObject *
context_getetiny(PyObject *self, PyObject *dummy UNUSED)
{
    return PyLong_FromSsize_t(mpd_etiny(CTX(self)));
}

static PyObject *
context_getetop(PyObject *self, PyObject *dummy UNUSED)
{
    return PyLong_FromSsize_t(mpd_etop(CTX(self)));
}

static int
context_setprec(PyObject *self, PyObject *value, void *closure UNUSED)
{
    mpd_context_t *ctx;
    mpd_ssize_t x;

    x = PyLong_AsSsize_t(value);
    if (x == -1 && PyErr_Occurred()) {
        return -1;
    }

    ctx = CTX(self);
    if (!mpd_qsetprec(ctx, x)) {
        return value_error_int(
            "valid range for prec is [1, MAX_PREC]");
    }

    return 0;
}

static int
context_setemin(PyObject *self, PyObject *value, void *closure UNUSED)
{
    mpd_context_t *ctx;
    mpd_ssize_t x;

    x = PyLong_AsSsize_t(value);
    if (x == -1 && PyErr_Occurred()) {
        return -1;
    }

    ctx = CTX(self);
    if (!mpd_qsetemin(ctx, x)) {
        return value_error_int(
            "valid range for Emin is [MIN_EMIN, 0]");
    }

    return 0;
}

static int
context_setemax(PyObject *self, PyObject *value, void *closure UNUSED)
{
    mpd_context_t *ctx;
    mpd_ssize_t x;

    x = PyLong_AsSsize_t(value);
    if (x == -1 && PyErr_Occurred()) {
        return -1;
    }

    ctx = CTX(self);
    if (!mpd_qsetemax(ctx, x)) {
        return value_error_int(
            "valid range for Emax is [0, MAX_EMAX]");
    }

    return 0;
}

#ifdef CONFIG_32
static PyObject *
context_unsafe_setprec(PyObject *self, PyObject *value)
{
    mpd_context_t *ctx = CTX(self);
    mpd_ssize_t x;

    x = PyLong_AsSsize_t(value);
    if (x == -1 && PyErr_Occurred()) {
        return NULL;
    }

    if (x < 1 || x > 1070000000L) {
        return value_error_ptr(
            "valid range for unsafe prec is [1, 1070000000]");
    }

    ctx->prec = x;
    Py_RETURN_NONE;
}

static PyObject *
context_unsafe_setemin(PyObject *self, PyObject *value)
{
    mpd_context_t *ctx = CTX(self);
    mpd_ssize_t x;

    x = PyLong_AsSsize_t(value);
    if (x == -1 && PyErr_Occurred()) {
        return NULL;
    }

    if (x < -1070000000L || x > 0) {
        return value_error_ptr(
            "valid range for unsafe emin is [-1070000000, 0]");
    }

    ctx->emin = x;
    Py_RETURN_NONE;
}

static PyObject *
context_unsafe_setemax(PyObject *self, PyObject *value)
{
    mpd_context_t *ctx = CTX(self);
    mpd_ssize_t x;

    x = PyLong_AsSsize_t(value);
    if (x == -1 && PyErr_Occurred()) {
        return NULL;
    }

    if (x < 0 || x > 1070000000L) {
        return value_error_ptr(
            "valid range for unsafe emax is [0, 1070000000]");
    }

    ctx->emax = x;
    Py_RETURN_NONE;
}
#endif

static int
context_setround(PyObject *self, PyObject *value, void *closure UNUSED)
{
    mpd_context_t *ctx;
    int x;

    x = getround(value);
    if (x == -1) {
        return -1;
    }

    ctx = CTX(self);
    if (!mpd_qsetround(ctx, x)) {
        INTERNAL_ERROR_INT("context_setround"); /* GCOV_NOT_REACHED */
    }

    return 0;
}

static int
context_setcapitals(PyObject *self, PyObject *value, void *closure UNUSED)
{
    mpd_ssize_t x;

    x = PyLong_AsSsize_t(value);
    if (x == -1 && PyErr_Occurred()) {
        return -1;
    }

    if (x != 0 && x != 1) {
        return value_error_int(
            "valid values for capitals are 0 or 1");
    }
    CtxCaps(self) = (int)x;

    return 0;
}

#ifdef EXTRA_FUNCTIONALITY
static int
context_settraps(PyObject *self, PyObject *value, void *closure UNUSED)
{
    mpd_context_t *ctx;
    uint32_t flags;

    flags = long_as_flags(value);
    if (flags & DEC_ERRORS) {
        return -1;
    }

    ctx = CTX(self);
    if (!mpd_qsettraps(ctx, flags)) {
        INTERNAL_ERROR_INT("context_settraps");
    }

    return 0;
}
#endif

static int
context_settraps_list(PyObject *self, PyObject *value)
{
    mpd_context_t *ctx;
    uint32_t flags;

    flags = list_as_flags(value);
    if (flags & DEC_ERRORS) {
        return -1;
    }

    ctx = CTX(self);
    if (!mpd_qsettraps(ctx, flags)) {
        INTERNAL_ERROR_INT("context_settraps_list");
    }

    return 0;
}

static int
context_settraps_dict(PyObject *self, PyObject *value)
{
    mpd_context_t *ctx;
    uint32_t flags;

    if (PyDecSignalDict_Check(value)) {
        flags = SdFlags(value);
    }
    else {
        flags = dict_as_flags(value);
        if (flags & DEC_ERRORS) {
            return -1;
        }
    }