PyDateTime_IMPORT() causes compiler warnings

[murrayc]

BPO	7463
Nosy	@abalkin, @jackdied

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/abalkin'
closed_at = <Date 2010-06-12.06:45:02.780>
created_at = <Date 2009-12-09.10:01:50.603>
labels = ['build']
title = 'PyDateTime_IMPORT() causes compiler warnings'
updated_at = <Date 2010-06-12.06:45:02.779>
user = 'https://bugs.python.org/murrayc'

bugs.python.org fields:

activity = <Date 2010-06-12.06:45:02.779>
actor = 'belopolsky'
assignee = 'belopolsky'
closed = True
closed_date = <Date 2010-06-12.06:45:02.780>
closer = 'belopolsky'
components = ['None']
creation = <Date 2009-12-09.10:01:50.603>
creator = 'murrayc'
dependencies = []
files = []
hgrepos = []
issue_num = 7463
keywords = []
message_count = 3.0
messages = ['96166', '99833', '107201']
nosy_count = 3.0
nosy_names = ['belopolsky', 'jackdied', 'murrayc']
pr_nums = []
priority = 'normal'
resolution = 'out of date'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'compile error'
url = 'https://bugs.python.org/issue7463'
versions = ['Python 2.5']

[murrayc]

At least in Python 2.5 and 2.6 (I haven't checked newer versions), the
PyDateTime_IMPORT() macro passes string literals to a function that
takes non-const char* parameters:

#define PyDateTime_IMPORT \
        PyDateTimeAPI = (PyDateTime_CAPI*) PyCObject_Import("datetime", \
                                                            "datetime_CAPI")

This makes it impossible to build code with warnings as errors, when
using that macro.

[jackdied]

changing the definition to (const char *) seems like the right thing to do - a quick grep of the Python source and a search on google codesearch only shows uses with either string literals or string literals cast to (char *) in order to silence a warning. I tried changing it on the 2.x trunk and it compiles with no warnings.

+1, any other opinions?

[abalkin]

PyCObject is deprecated in 2.7 and removed in 3.x. PyCapsule_Import() should be used instead of PyCObject_Import() and it already has correct signature:

Include/pycapsule.h:PyAPI_FUNC(void *) PyCapsule_Import(const char *name, int no_block);

Since this is not a bug, I don't think it is appropriate to change it in 2.x.