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Today's Topics:
1. [mingw] #42344: Implement a generic infrastructure to
facilitate run-time linking of API functions (MinGW Notification List)
2. [mingw] #41567: Some new Win32 APIs are missing from w32api
(MinGW Notification List)
----------------------------------------------------------------------
Message: 1
Date: Fri, 21 May 2021 20:46:00 +0100
From: MinGW Notification List <[email protected]>
To: OSDN Ticket System <[email protected]>
Subject: [MinGW-Notify] [mingw] #42344: Implement a generic
infrastructure to facilitate run-time linking of API functions
Message-ID: <[email protected]>
Content-Type: text/plain; charset=UTF-8
#42344: Implement a generic infrastructure to facilitate run-time linking of
API functions
Open Date: 2021-05-21 20:46
Last Update: 2021-05-21 20:46
URL for this Ticket:
https://osdn.net//projects/mingw/ticket/42344
RSS feed for this Ticket:
https://osdn.net/ticket/ticket_rss.php?group_id=3917&tid=42344
---------------------------------------------------------------------
Last Changes/Comment on this Ticket:
2021-05-21 20:46 Updated by: keith
* New Ticket "Implement a generic infrastructure to facilitate run-time
linking of API functions" created
---------------------------------------------------------------------
Ticket Status:
Reporter: keith
Owner: keith
Type: Feature Request
Status: Open [Owner assigned]
Priority: 5 - Medium
MileStone: (None)
Component: WSL
Severity: 5 - Medium
Resolution: None
---------------------------------------------------------------------
Ticket details:
As support for new (Windows version-dependent) APIs is added to MinGW, there is
increased potential for creating an application which will not load, much less
run, on legacy Windows versions; the typical manifestation of such a load
failure is that the process crashes with an "entry point not found" exception,
for the unsupported DLL function, before the main() function even gets control,
so there's no opportunity to handle the exception.
The only way to mitigate such exceptions, such that the application retains
control, is to always link potentially unsupported API functions dynamically,
at run-time, by retrieval of an entry-point reference, using GetProcAddress(),
and to always invoke the function via the reference pointer, (and never call it
directly, by name). The mechanism for dynamically linking such functions is
mostly the same, in each case, often resulting in significant repetitive
coding; it would be a great convenience, if MinGW were to implement a generic
API infrastructure, to encapsulate the common features of the required run-time
linking interface.
--
Ticket information of MinGW - Minimalist GNU for Windows project
MinGW - Minimalist GNU for Windows Project is hosted on OSDN
Project URL: https://osdn.net/projects/mingw/
OSDN: https://osdn.net
URL for this Ticket:
https://osdn.net/projects/mingw/ticket/42344
RSS feed for this Ticket:
https://osdn.net/ticket/ticket_rss.php?group_id=3917&tid=42344
------------------------------
Message: 2
Date: Fri, 21 May 2021 23:49:17 +0100
From: MinGW Notification List <[email protected]>
To: OSDN Ticket System <[email protected]>
Subject: [MinGW-Notify] [mingw] #41567: Some new Win32 APIs are
missing from w32api
Message-ID: <[email protected]>
Content-Type: text/plain; charset=UTF-8
#41567: Some new Win32 APIs are missing from w32api
Open Date: 2021-02-12 14:20
Last Update: 2021-05-21 23:49
URL for this Ticket:
https://osdn.net//projects/mingw/ticket/41567
RSS feed for this Ticket:
https://osdn.net/ticket/ticket_rss.php?group_id=3917&tid=41567
---------------------------------------------------------------------
Last Changes/Comment on this Ticket:
2021-05-21 23:49 Updated by: keith
Comment:
Reply To keith
... there is a potential problem with simply adding the import library thunks,
for the missing functions. It's not insurmountable — in fact, it's easy enough
to do — and perhaps is more of a caveat ...
Fundamentally, the caveat is that, once the header files have been updated, and
the import library thunks have been added, any code which is compiled with an
appropriate NTDDI_VERSION definition may call the new functions directly, and,
in the absence of coding errors, the program will compile, and link
successfully. However, it will not load, much less run, on any legacy version
of Windows, ...
... The defensive way, to manage this caveat, is to always call potentially
unsupported functions via a pointer retrieved by GetProcAddress(), and never
call them directly; ... I've written quite a few such "legacy capable"
functions, in the past year or so; they all look very similar, and I'm
seriously considering factoring out the commonality, into generic helper
functions, (perhaps in libkernel32.a), to make the task less repetitive, but
that's probably a subject for another feature request ticket.
I've now opened feature request #42344, relating to this. On that, I plan to
develop the concept, which I will illustrate by a simple example derived from
this very ticket, to show how run-time linked stubs — for the pseudo-console
API, in this example case — might be integrated directly into the MinGW headers
themselves.
---------------------------------------------------------------------
Ticket Status:
Reporter: eliz
Owner: (None)
Type: Feature Request
Status: Open
Priority: 5 - Medium
MileStone: (None)
Component: WSL
Severity: 5 - Medium
Resolution: None
---------------------------------------------------------------------
Ticket details:
To compile programs that use the Pseudo Console feature introduced recently
with Windows 10, there's a need in several additions to the MinGW w32api
headers and import libraries.
First, we need a value for _WIN32_WINNT that specifies Windows 10, in
sdkddkver.h:
#define _WIN32_WINNT_WIN10 0x0A00
Second, we need functions, data structures, and macros to create and update
lists of attributes for process and thread creation. These are:
InitializeProcThreadAttributeList function
UpdateProcThreadAttribute function
DeleteProcThreadAttributeList function
PROC_THREAD_ATTRIBUTE_LIST structure
STARTUPINFOEX structure
PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE macro
Other PROC_THREAD_ATTRIBUTE_* macros
These seem to be supported since Windows 7, with the exception of
PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE, which is only supported since Windows 10,
and STARTUPINFOEX, which is supported since Vista. I think the proper place
for them is in the winbase.h header file.
We also need the EXTENDED_STARTUPINFO_PRESENT flag for the CreateProcess
function (this flag is supported since Vista and should be in winbase.h).
And finally, we need the functions, data types, and macros to manipulate
pseudo-consoles, available only since Windows 10:
CreatePseudoConsole function
ClosePseudoConsole function
ResizePseudoConsole function
HPCON data type
Thanks in advance for providing these.
--
Ticket information of MinGW - Minimalist GNU for Windows project
MinGW - Minimalist GNU for Windows Project is hosted on OSDN
Project URL: https://osdn.net/projects/mingw/
OSDN: https://osdn.net
URL for this Ticket:
https://osdn.net/projects/mingw/ticket/41567
RSS feed for this Ticket:
https://osdn.net/ticket/ticket_rss.php?group_id=3917&tid=41567
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