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Sun Feb 11 02:37:28 JST 2018
Fork#37938: Conflicts in time_t type definition between MSVCRT.DLL, UCRTBASE.DLL, and VC++ non-free runtimes
Open Date: 2018-02-03 18:05
Last Update: 2018-02-10 17:37
URL for this Ticket:
https://osdn.net//projects/mingw/ticket/37938
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Last Changes/Comment on this Ticket:
2018-02-10 17:37 Updated by: keith
Comment:
Reply To earnie
I do not appreciate the antagonistic tone of your comment; neither do I appreciate your apparent underhand attempt to resurrect, in public, a private disagreement which I thought we had put behind us.
And what we engineer should not interfere with someone compiling the code with Visual C++ which must "blindly conform" to that documentation.
Of course, but how on earth could any such engineering in any way impact users of Visual C++? They will be using Microsoft's headers and implementations; for them, our engineering is irrelevant.
The engineering needs to use the versioning macros to determine what the default for time_t is.
And this is exactly what my existing implementations do, for 32-bit Windows; the purpose of this ticket is to invite pragmatic discussion of what further changes, if any, may be required to support 64-bit Windows.
Any missing element in MSVCRT.DLL ...
There are no missing elements, among the generically named time_t dependent functions, from any version of MSVCRT.DLL. The omissions are the 64-bit time_t explicit overrides, prior to Win2K, and 32-bit explicit "overrides", (on 32-bit Windows, MSVCRT.DLL's generically named implementations unequivocally represent time_t as a 32-bit entity), prior to Vista.
... or UCRTBASE.DLL needs to be managed with a MinGW specific element which mimics the MS elements.
UCRTBASE.DLL appears to exhibit the same limitations as MSVCR80.DLL, and its successors; all generically named function implementations are missing, and all must be emulated by in-line redirection within header files. Once again, I already have implementations which do this for 32-bit Windows; this ticket needs only to identify any changes which may be needed to support 64-bit Windows.
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Ticket Status:
Reporter: keith
Owner: keith
Type: Issues
Status: Open [Owner assigned]
Priority: 5 - Medium
MileStone: (None)
Component: WSL
Severity: 5 - Medium
Resolution: None
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Ticket details:
According to this Microsoft on-line documentation:
In versions of Visual C++ and Microsoft C/C++ before Visual C++ 2005, time_t was a long int (32 bits)
and hence could not be used for dates past 3:14:07 January 19, 2038, UTC. time_t is now equivalent to
__time64_t by default, but defining _USE_32BIT_TIME_T changes time_t to __time32_t and forces many time
functions to call versions that take the 32-bit time_t. For more information, see Standard Types and
comments in the documentation for the individual time functions.
While this may be true, for applications which are built using Microsoft's Visual C++, (specifically from the 2005 version onward), and linked with the accompanying non-free versions of Microsoft's C-Runtime library, (from MSVCR80.DLL onward, and perhaps also with the pseudo-free UCRTBASE.DLL), it is manifestly untrue for applications which are linked with the pseudo-free MSVCRT.DLL, (the normal case for MinGW applications), as it is for applications which are built with, and linked with the C-Runtime libraries which accompanied, earlier (legacy) versions of Microsoft's Visual C++, (i.e. applications which are linked with Microsoft's non-free runtime libraries pre-dating MSVCR80.DLL).
We need to engineer a time management API which will accommodate the disparities between MSVCRT.DLL, UCRTBASE.DLL, and Microsoft's post-2005 Visual C++ implementations of various time management functions, and we must recognise that our API cannot blindly conform to the above paragraph from Microsoft's current documentation.
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