> The problem with this bug report is that there is little chance that it gets resolved in the near term, and it's quite possible that it will stay open for years. Somebody would have to sit down and start producing patches to fix these warnings correctly, before the actual patch can be applied.


That's perfectly reasonable. In the mean time, we may be able to dramatically reduce the timetable by suppressing warnings - C4232 for example - which don't offer anything on a case-by-case basis.

C4232(*), for example, warns any time we use the address of a `dllimport`ed function. mpd_mallocfunc, mpd_free, and friends - see https://hg.python.org/cpython/file/tip/Modules/_decimal/libmpdec/memory.c#l44 - are assigned malloc, free, etc... but is it safe to ignore?



And then there are warnings that are safe to ignore in certain places, like C4310 in the _Py_ERROR_SURROGATEESCAPE case of PyUnicode_DecodeASCII in unicodeobject.c (https://hg.python.org/cpython/file/tip/Objects/unicodeobject.c#l6897):

            if (error_handler == _Py_ERROR_REPLACE)
                PyUnicode_WRITE(kind, data, writer.pos, 0xfffd);

...(here, the constant value 0xfffd is cast to a Py_UCS1, truncating it, inside a macro) but are not valid in others, like these insertint calls in PyInit_msvcrt, in msvcrtmodule.c (https://hg.python.org/cpython/file/tip/PC/msvcrtmodule.c#l538):

    insertint(d, "CRTDBG_FILE_STDERR", (int)_CRTDBG_FILE_STDERR);
    insertint(d, "CRTDBG_FILE_STDOUT", (int)_CRTDBG_FILE_STDOUT);
    insertint(d, "CRTDBG_REPORT_FILE", (int)_CRTDBG_REPORT_FILE);


...(here, _CRTDBG_FILE_STDERR, _CRTDBG_FILE_STDOUT, and _CRTDBG_REPORT_FILE, are _HFILEs, which is a void*, here {((_HFILE)(intptr_t)-4), ((_HFILE)(intptr_t)-5), and ((_HFILE)(intptr_t)-6)} respectively; the void* is truncated to an int in 64 bit builds)

(*)C4232, "nonstandard extension used : 'identifier' : address of dllimport 'dllimport' is not static, identity not guaranteed",  (https://msdn.microsoft.com/en-us/library/9a1sy630.aspx)

I will try to sort a few of the easy categories, so we can discuss more generally.