cosmopolitan/third_party/python/Include/longintrepr.h
Justine Tunney b420ed8248 Undiamond Python headers
This change gets the Python codebase into a state where it conforms to
the conventions of this codebase. It's now possible to include headers
from Python, without worrying about ordering. Python has traditionally
solved that problem by "diamonding" everything in Python.h, but that's
problematic since it means any change to any Python header invalidates
all the build artifacts. Lastly it makes tooling not work. Since it is
hard to explain to Emacs when I press C-c C-h to add an import line it
shouldn't add the header that actually defines the symbol, and instead
do follow the nonstandard Python convention.

Progress has been made on letting Python load source code from the zip
executable structure via the standard C library APIs. System calss now
recognizes zip!FILENAME alternative URIs as equivalent to zip:FILENAME
since Python uses colon as its delimiter.

Some progress has been made on embedding the notice license terms into
the Python object code. This is easier said than done since Python has
an extremely complicated ownership story.

- Some termios APIs have been added
- Implement rewinddir() dirstream API
- GetCpuCount() API added to Cosmopolitan Libc
- More bugs in Cosmopolitan Libc have been fixed
- zipobj.com now has flags for mangling the path
- Fixed bug a priori with sendfile() on certain BSDs
- Polyfill F_DUPFD and F_DUPFD_CLOEXEC across platforms
- FIOCLEX / FIONCLEX now polyfilled for fast O_CLOEXEC changes
- APE now supports a hybrid solution to no-self-modify for builds
- Many BSD-only magnums added, e.g. O_SEARCH, O_SHLOCK, SF_NODISKIO
2021-08-12 14:07:40 -07:00

98 lines
3.8 KiB
C

#ifndef Py_LIMITED_API
#ifndef Py_LONGINTREPR_H
#define Py_LONGINTREPR_H
#include "third_party/python/Include/longobject.h"
#include "third_party/python/Include/object.h"
#include "third_party/python/Include/pyport.h"
COSMOPOLITAN_C_START_
/* clang-format off */
/* This is published for the benefit of "friends" marshal.c and _decimal.c. */
/* Parameters of the integer representation. There are two different
sets of parameters: one set for 30-bit digits, stored in an unsigned 32-bit
integer type, and one set for 15-bit digits with each digit stored in an
unsigned short. The value of PYLONG_BITS_IN_DIGIT, defined either at
configure time or in pyport.h, is used to decide which digit size to use.
Type 'digit' should be able to hold 2*PyLong_BASE-1, and type 'twodigits'
should be an unsigned integer type able to hold all integers up to
PyLong_BASE*PyLong_BASE-1. x_sub assumes that 'digit' is an unsigned type,
and that overflow is handled by taking the result modulo 2**N for some N >
PyLong_SHIFT. The majority of the code doesn't care about the precise
value of PyLong_SHIFT, but there are some notable exceptions:
- long_pow() requires that PyLong_SHIFT be divisible by 5
- PyLong_{As,From}ByteArray require that PyLong_SHIFT be at least 8
- long_hash() requires that PyLong_SHIFT is *strictly* less than the number
of bits in an unsigned long, as do the PyLong <-> long (or unsigned long)
conversion functions
- the Python int <-> size_t/Py_ssize_t conversion functions expect that
PyLong_SHIFT is strictly less than the number of bits in a size_t
- the marshal code currently expects that PyLong_SHIFT is a multiple of 15
- NSMALLNEGINTS and NSMALLPOSINTS should be small enough to fit in a single
digit; with the current values this forces PyLong_SHIFT >= 9
The values 15 and 30 should fit all of the above requirements, on any
platform.
*/
#if PYLONG_BITS_IN_DIGIT == 30
typedef uint32_t digit;
typedef int32_t sdigit; /* signed variant of digit */
typedef uint64_t twodigits;
typedef int64_t stwodigits; /* signed variant of twodigits */
#define PyLong_SHIFT 30
#define _PyLong_DECIMAL_SHIFT 9 /* max(e such that 10**e fits in a digit) */
#define _PyLong_DECIMAL_BASE ((digit)1000000000) /* 10 ** DECIMAL_SHIFT */
#elif PYLONG_BITS_IN_DIGIT == 15
typedef unsigned short digit;
typedef short sdigit; /* signed variant of digit */
typedef unsigned long twodigits;
typedef long stwodigits; /* signed variant of twodigits */
#define PyLong_SHIFT 15
#define _PyLong_DECIMAL_SHIFT 4 /* max(e such that 10**e fits in a digit) */
#define _PyLong_DECIMAL_BASE ((digit)10000) /* 10 ** DECIMAL_SHIFT */
#else
#error "PYLONG_BITS_IN_DIGIT should be 15 or 30"
#endif
#define PyLong_BASE ((digit)1 << PyLong_SHIFT)
#define PyLong_MASK ((digit)(PyLong_BASE - 1))
#if PyLong_SHIFT % 5 != 0
#error "longobject.c requires that PyLong_SHIFT be divisible by 5"
#endif
/* Long integer representation.
The absolute value of a number is equal to
SUM(for i=0 through abs(ob_size)-1) ob_digit[i] * 2**(SHIFT*i)
Negative numbers are represented with ob_size < 0;
zero is represented by ob_size == 0.
In a normalized number, ob_digit[abs(ob_size)-1] (the most significant
digit) is never zero. Also, in all cases, for all valid i,
0 <= ob_digit[i] <= MASK.
The allocation function takes care of allocating extra memory
so that ob_digit[0] ... ob_digit[abs(ob_size)-1] are actually available.
CAUTION: Generic code manipulating subtypes of PyVarObject has to
aware that ints abuse ob_size's sign bit.
*/
struct _longobject {
PyObject_VAR_HEAD
digit ob_digit[1];
};
PyLongObject * _PyLong_New(Py_ssize_t);
/* Return a copy of src. */
PyObject * _PyLong_Copy(PyLongObject *src);
COSMOPOLITAN_C_END_
#endif /* !Py_LONGINTREPR_H */
#endif /* Py_LIMITED_API */