gdb/libpython.py: Update PyLongObjectPtr docstring (GH-118438)

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Andrej 2024-05-02 13:57:45 +05:00 committed by GitHub
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1 changed files with 10 additions and 6 deletions

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@ -255,7 +255,7 @@ class PyObjectPtr(object):
Derived classes will override this.
For example, a PyIntObject* with ob_ival 42 in the inferior process
For example, a PyLongObjectPtr* with long_value 42 in the inferior process
should result in an int(42) in this process.
visited: a set of all gdb.Value pyobject pointers already visited
@ -867,7 +867,7 @@ class PyLongObjectPtr(PyObjectPtr):
def proxyval(self, visited):
'''
Python's Include/longobjrep.h has this declaration:
Python's Include/longinterpr.h has this declaration:
typedef struct _PyLongValue {
uintptr_t lv_tag; /* Number of digits, sign and flags */
@ -876,14 +876,18 @@ class PyLongObjectPtr(PyObjectPtr):
struct _longobject {
PyObject_HEAD
_PyLongValue long_value;
_PyLongValue long_value;
};
with this description:
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.
SUM(for i=0 through ndigits-1) ob_digit[i] * 2**(PyLong_SHIFT*i)
The sign of the value is stored in the lower 2 bits of lv_tag.
- 0: Positive
- 1: Zero
- 2: Negative
The third lowest bit of lv_tag is reserved for an immortality flag, but is
not currently used.
where SHIFT can be either:
#define PyLong_SHIFT 30