*.idl: Use correct type for BSTR strings in the defaultvalue() statements.

[Nikolay Sivov]

On Friday, 6 November 2015, Dmitry Timoshkov <dmitry at baikal.ru> wrote:

> Nikolay Sivov <bunglehead at gmail.com <javascript:;>> wrote:
>
> > > Nikolay Sivov <bunglehead at gmail.com <javascript:;> <javascript:;>>
> wrote:
> > >
> > > > > This matches midl/PSDK syntax, and allows to use Wine headers for
> > > compiling
> > > > > applications with a C++ win32/win64 compiler. In order to be
> usable by
> > > C++
> > > > > unix compilers widl needs to emit appropriate statically
> initialized
> > > WCHAR
> > > > > strings, but that's a different problem, currently the generated
> Wine
> > > headers
> > > > > with default(BSTR) statements can't be used with C++ at all.
> > > > >
> > > >
> > > > Where do you see this? Mshtml.idl from Windows 10 SDK doesn't use
> this
> > > > notation, and in fact only fsrm*.idl files do, so it's not a common
> > > > practice.
> > >
> > > midl has a built-in "magic" for handling defaultvalue() for BSTR
> strings,
> > > that's why PSDK headers are not consistent in that regard: some of them
> > > use defaultvalue("") while others use defaultvalue(L""). But using this
> > > magic is not necessary if the header uses appropriate type for the
> default
> > > value. So fixing an .idl should be preferrable IMO to adding support
> for
> > > magic behaviour to widl.
> >
> > All headers except about 4 we don't have, use it like we do. All the
> magic
> > is to add a prefix during header generation, it doesn't look that hard,
> and
> > will get consistent result for idls that don't cone with wine.
>
> I don't really follow your objections. It's pretty clear that Wine .idl
> files with defaultvalue("") statements for BSTR type are broken. There
> are two ways to fix them:
> 1) fix .idl files, widl and midl already have proper support for L""
> syntax.
> 2) don't fix .idl files (just because PSDK has them that way) and add magic
> handling for BSTR to widl.
> Fixing .idl files is a natural and easy fix, what syntax uses PSDK doesn't
> matter al all, it's even better to differ from PSDK headers in this case.


 Assigning static string in attempt to initialize BSTR is broken too of
course.

>
> > > > Generated headers should use L"", like you said. But only in
> > > > case of empty strings.
> > >
> > > midl always generates L"" syntax, regardless whether it's an empty
> string
> > > or not.
> >
> >
> > I don't see this in mshtml.h when default value is not an empty string.
>
> Probably midl doesn't correctly handle even the magic that it's supposed to
> support. That just confirms that adding "magic" support for defaultvalue()
> to widl wouldn't solve the problem completely, and support for this "magic"
> would need adding even more magic to match midl brokeness.
>
> > > > Also leaving this broken for everything that's
> > > > not PSDK compiler doesn't sound right.
> > >
> > > mingw/borland/any other wine32 compiler also benefit from this change.
> > > It doesn't make sense to have it broken at all, but at least fixing
> > > the .idl side of breakage should be considered as the first step, and
> > > make the generated headers actually usable for the win32 platform.
> > >
> > > Since it only affects cpp case, that we don't use, how does it help
> > building wine?
> >
> > And more importantly what will happen to gcc if you try to build with
> this
> > addition?
>
> gcc does build generated headers just fine. I wonder why you don't care
> what
> happens to gcc when it builds with current broken headers.
>
>
Currently our headers don't have L"" strings, and we don't use it
anywhere.

> --
> Dmitry.
>
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