Keith Marshall
keith****@users*****
Fri Jun 29 19:10:10 JST 2018
On 29/06/18 07:26, Eli Zaretskii wrote: >> From: David Gressett <DGres****@amli-*****> >> Date: Thu, 28 Jun 2018 21:52:07 -0500 >> ../../../src/gcc-7.3.0/gcc/ada/rtinit.c:195:44: error: >> '_O_U16TEXT' was not declared in this scope >> __gnat_current_ccs_encoding = _O_U16TEXT; >> >> The other two undefined items were _O_WTEXT and _O_U8TEXT. >> For all three of these, the compiler suggested _O_TEXT as an >> alternative. >> >> rtinit.c includes <fcntl.h> which defines the three undefined items: >> >> #if (__MSVCRT_VERSION__ >= 0x0800) >> #define _O_WTEXT 0x10000 >> #define _O_U16TEXT 0x20000 >> #define _O_U8TEXT 0x40000 >> #endif >> >> fcntl.h includes _mingw.h which includes mscrtver.h, which defines >> a default value for __MSVCRT_VERSION__ >> >> The default value is 0x0600, so unless an overriding #define >> produces a larger value, these constants will be undefined. > > AFAIU, the above means that the Ada compiler has dropped support of > Windows versions before Vista, and the compiler you produce will be > unable to run on those older versions as it does on Windows 7 and > later. Unless, that is, the source has some fallback for those older > versions (and _O_TEXT sounds like a good idea to me up front), but I > didn't look at the sources to see if they do have such a fallback, and > I don't really understand what that will do, since UTF-16 text will > not be supported that way. > > If you never intend to have your compiler to run on older systems, > just define __MSVCRT_VERSION__ to the higher number, I'd say. > > Keith will probably have a better insight. Well, I really cannot condone any suggestion to arbitrarily define __MSVCRT_VERSION__; its purpose is to declare intent to link with one of Microsoft's non-free (not freely distributable) runtimes, such as MSVCR80.DLL or later, *instead* of the OS-provided MSVCRT.DLL. As such, the *only* way it should *ever* be defined to a non-default value is via a custom GCC specs file, which *replaces* MSVCRT.DLL with the corresponding non-free alternative, in the list of default libraries passed to the linker. As David notes, the default value for __MSVCRT_VERSION__ is specified as 0x0600; this, or any lesser value, is interpreted as a declaration of intent to maintain compatibility with default MSVCRT.DLL linking behaviour. Comments within <msvcrtver.h>, (for which I assume David's reference to <mscrtver.h> is a typo), explain this. That said, if Vista and later versions of MSVCRT.DLL now expose APIs to which these __MSVCRT_VERSION__ restricted constants relate, then the restriction in <fcntl.h> should reflect that, with a _WIN32_WINNT minimum version test to complement the __MSVCRT_VERSION__ restriction. Would anyone care to propose a test case for such version specific support? I no longer use Windows for any daily purpose, but I do still have the ability to test compatibility for WinXP and Win7, running either as a virtual machine. Would anyone else be able to assist with testing on other (esp. legacy) Windows versions? -- Regards, Keith. Public key available from keys.gnupg.net Key fingerprint: C19E C018 1547 DE50 E1D4 8F53 C0AD 36C6 347E 5A3F -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: OpenPGP digital signature Url : https://lists.osdn.me/mailman/archives/mingw-users/attachments/20180629/36ec04fe/attachment.pgp
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