GV

GeezerVison

The World Wide Web, restored to 800 pixels of glory.

Home|About|Gaming cabinet|Archives|How it works|Starter sites

On this site

  • Sign in
  • ActionsCI/CD and automation
  • CodespacesCloud development environments
  • All Features
  • Documentation
  • Training
  • Certifications
  • Build with Copilot
  • Customize Copilot
  • Integrations
  • Trending repos
  • GitHub Sponsors
  • Developer articles
  • Enterprises

This view

  • Original page
  • New address

GeezerVison is showing github.com — bpo-32782: PEP3118 itemsize of an empty ctypes array should not be 0 by eric-wieser · Pull Request #5576 · python/cpython

bpo-32782: PEP3118 itemsize of an empty ctypes array should not be 0 #5576

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
mdickinson merged 6 commits into python:main from eric-wieser:ctypes-empty-array-itemsize
Dec 23, 2022

Uh oh!

There was an error while loading. Please reload this page.
Merged

bpo-32782: PEP3118 itemsize of an empty ctypes array should not be 0 #5576

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
f4e3ca9
bpo-32782: PEP3118 itemsize of an empty ctypes array should not be 0
eric-wieser Feb 7, 2018
dd2069f
bpo-32782: Avoid touching python attributes when the C attribute is a…
eric-wieser Jun 7, 2019
0cabf5d
Merge remote-tracking branch 'upstream/main' into ctypes-empty-array-…
eric-wieser Jul 7, 2022
d459459
Merge remote-tracking branch 'upstream/main' into ctypes-empty-array-…
eric-wieser Dec 15, 2022
accc969
Merge branch 'main' into ctypes-empty-array-itemsize
eric-wieser Dec 15, 2022
ff4dd22
Merge branch 'main' into ctypes-empty-array-itemsize
eric-wieser Dec 22, 2022
File filter
Filter by extension
Clear filters
Conversations
Failed to load comments.
Loading

Uh oh!

There was an error while loading. Please reload this page.
Jump to
Jump to file
Failed to load files.
Loading

Uh oh!

There was an error while loading. Please reload this page.
Diff view
Diff view

There are no files selected for viewing

2 changes: 2 additions & 0 deletions 2 Lib/test/test_ctypes/test_pep3118.py
Show comments
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -176,7 +176,9 @@ class Complete(Structure):
## arrays and pointers

(c_double * 4, "<d", (4,), c_double),
(c_double * 0, "<d", (0,), c_double),
(c_float * 4 * 3 * 2, "<f", (2,3,4), c_float),
(c_float * 4 * 0 * 2, "<f", (2,0,4), c_float),
(POINTER(c_short) * 2, "&<" + s_short, (2,), POINTER(c_short)),
(POINTER(c_short) * 2 * 3, "&<" + s_short, (3,2,), POINTER(c_short)),
(POINTER(c_short * 2), "&(2)<" + s_short, (), POINTER(c_short)),
Expand Down
3 changes: 3 additions & 0 deletions 3 Misc/NEWS.d/next/Core and Builtins/2018-02-06-23-21-13.bpo-32782.EJVSfR.rst
Show comments
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
``ctypes`` arrays of length 0 now report a correct itemsize when a
``memoryview`` is constructed from them, rather than always giving a value
of 0.
33 changes: 25 additions & 8 deletions 33 Modules/_ctypes/_ctypes.c
Show comments
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2731,11 +2731,33 @@ static PyMemberDef PyCData_members[] = {
{ NULL },
};

static int PyCData_NewGetBuffer(PyObject *myself, Py_buffer *view, int flags)
/* Find the innermost type of an array type, returning a borrowed reference */
static PyObject *
PyCData_item_type(PyObject *type)
{
if (PyCArrayTypeObject_Check(type)) {
StgDictObject *stg_dict;
PyObject *elem_type;

/* asserts used here as these are all guaranteed by construction */
stg_dict = PyType_stgdict(type);
assert(stg_dict);
elem_type = stg_dict->proto;
assert(elem_type);
return PyCData_item_type(elem_type);
}
else {
return type;
}
}

static int
PyCData_NewGetBuffer(PyObject *myself, Py_buffer *view, int flags)
{
CDataObject *self = (CDataObject *)myself;
StgDictObject *dict = PyObject_stgdict(myself);
Py_ssize_t i;
PyObject *item_type = PyCData_item_type((PyObject*)Py_TYPE(myself));
StgDictObject *item_dict = PyType_stgdict(item_type);

if (view == NULL) return 0;

Expand All @@ -2747,12 +2769,7 @@ static int PyCData_NewGetBuffer(PyObject *myself, Py_buffer *view, int flags)
view->format = dict->format ? dict->format : "B";
view->ndim = dict->ndim;
view->shape = dict->shape;
view->itemsize = self->b_size;
if (view->itemsize) {
for (i = 0; i < view->ndim; ++i) {
view->itemsize /= dict->shape[i];
}
}
view->itemsize = item_dict->size;
view->strides = NULL;
view->suboffsets = NULL;
view->internal = NULL;
Expand Down
Add this suggestion to a batch that can be applied as a single commit. This suggestion is invalid because no changes were made to the code. Suggestions cannot be applied while the pull request is closed. Suggestions cannot be applied while viewing a subset of changes. Only one suggestion per line can be applied in a batch. Add this suggestion to a batch that can be applied as a single commit. Applying suggestions on deleted lines is not supported. You must change the existing code in this line in order to create a valid suggestion. Outdated suggestions cannot be applied. This suggestion has been applied or marked resolved. Suggestions cannot be applied from pending reviews. Suggestions cannot be applied on multi-line comments. Suggestions cannot be applied while the pull request is queued to merge. Suggestion cannot be applied right now. Please check back later.
You are visitor 01402503 — GeezerVison does not store the pages you look up.
Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.