[PATCH v2 1/8] dllhost: Add stub implementation.

[Dmitry Timoshkov]

Signed-off-by: Dmitry Timoshkov 
---
 configure                    |  2 ++
 configure.ac                 |  1 +
 programs/dllhost/Makefile.in |  7 ++++++
 programs/dllhost/dllhost.c   | 45 ++++++++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+)
 create mode 100644 programs/dllhost/Makefile.in
 create mode 100644 programs/dllhost/dllhost.c

diff --git a/configure b/configure
index 5dadd827dbd..30bb02edf67 100755
--- a/configure
+++ b/configure
@@ -1849,6 +1849,7 @@ enable_conhost
 enable_control
 enable_cscript
 enable_dism
+enable_dllhost
 enable_dplaysvr
 enable_dpnsvr
 enable_dpvsetup
@@ -22658,6 +22659,7 @@ wine_fn_config_makefile programs/conhost/tests enable_tests
 wine_fn_config_makefile programs/control enable_control
 wine_fn_config_makefile programs/cscript enable_cscript
 wine_fn_config_makefile programs/dism enable_dism
+wine_fn_config_makefile programs/dllhost enable_dllhost
 wine_fn_config_makefile programs/dplaysvr enable_dplaysvr
 wine_fn_config_makefile programs/dpnsvr enable_dpnsvr
 wine_fn_config_makefile programs/dpvsetup enable_dpvsetup
diff --git a/configure.ac b/configure.ac
index e3d797d790d..194fe8df783 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3549,6 +3549,7 @@ WINE_CONFIG_MAKEFILE(programs/conhost/tests)
 WINE_CONFIG_MAKEFILE(programs/control)
 WINE_CONFIG_MAKEFILE(programs/cscript)
 WINE_CONFIG_MAKEFILE(programs/dism)
+WINE_CONFIG_MAKEFILE(programs/dllhost)
 WINE_CONFIG_MAKEFILE(programs/dplaysvr)
 WINE_CONFIG_MAKEFILE(programs/dpnsvr)
 WINE_CONFIG_MAKEFILE(programs/dpvsetup)
diff --git a/programs/dllhost/Makefile.in b/programs/dllhost/Makefile.in
new file mode 100644
index 00000000000..a92add9c2f0
--- /dev/null
+++ b/programs/dllhost/Makefile.in
@@ -0,0 +1,7 @@
+MODULE    = dllhost.exe
+IMPORTS   = ole32
+
+EXTRADLLFLAGS = -mwindows -municode
+
+C_SRCS = \
+	dllhost.c
diff --git a/programs/dllhost/dllhost.c b/programs/dllhost/dllhost.c
new file mode 100644
index 00000000000..10bfb084213
--- /dev/null
+++ b/programs/dllhost/dllhost.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2022 Dmitry Timoshkov
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <stdarg.h>
+
+#include <windef.h>
+#include <winbase.h>
+#include <objbase.h>
+
+#include "wine/debug.h"
+
+WINE_DEFAULT_DEBUG_CHANNEL(dllhost);
+
+int WINAPI wWinMain(HINSTANCE hinst, HINSTANCE previnst, LPWSTR cmdline, int showcmd)
+{
+    HRESULT hr;
+    CLSID clsid;
+
+    CoInitializeEx(NULL, COINIT_MULTITHREADED);
+
+    hr = CLSIDFromString(cmdline, &clsid);
+    if (hr == S_OK)
+    {
+        FIXME("hosting object %s is not implemented\n", wine_dbgstr_guid(&clsid));
+    }
+
+    CoUninitialize();
+
+    return 0;
+}

[Huw Davies]

On Tue, Feb 22, 2022 at 05:49:54PM +0300, Dmitry Timoshkov wrote:
> +int WINAPI wWinMain(HINSTANCE hinst, HINSTANCE previnst, LPWSTR cmdline, int showcmd)
> +{
> - HRESULT hr;
> - CLSID clsid;
> -
> - CoInitializeEx(NULL, COINIT_MULTITHREADED);
> -
> - hr = CLSIDFromString(cmdline, &clsid);

It looks like Windows uses the cmdline:

dllhost.exe /PROCESSID:{GUID}

Huw.

[Dmitry Timoshkov]

Huw Davies  wrote:
> On Tue, Feb 22, 2022 at 05:49:54PM +0300, Dmitry Timoshkov wrote:
> > +int WINAPI wWinMain(HINSTANCE hinst, HINSTANCE previnst, LPWSTR cmdline, int showcmd)
> > +{
> > - HRESULT hr;
> > - CLSID clsid;
> > -
> > - CoInitializeEx(NULL, COINIT_MULTITHREADED);
> > -
> > - hr = CLSIDFromString(cmdline, &clsid);
>
> It looks like Windows uses the cmdline:
>
> dllhost.exe /PROCESSID:{GUID}

MSDN's "Using the System-Supplied Surrogate" article
https://docs.microsoft.com/en-us/windows/win32/com/using-the-system-supplied...
and a pretty good guide for writing custom surrogate (which I follow in my work)
https://docs.microsoft.com/en-us/windows/win32/com/writing-a-custom-surrogat...
they both mention only "CLSID on the launch command line".
Also the prototype patch attached to the bug
https://bugs.winehq.org/show_bug.cgi?id=20296 
passes just {GUID} on the command line.

Where do you see /PROCESSID mentioned for the surrogate process context?
Also it's not clear to me that /PROCESSID belongs to the hosted object,
and not something else, like really some process id.

Probably that's an internal implementation detail, and I'm open to use
whatever is deemed to be appropriate.

[Huw Davies]

On Wed, Feb 23, 2022 at 03:36:55PM +0300, Dmitry Timoshkov wrote:
> Huw Davies  wrote:
> > On Tue, Feb 22, 2022 at 05:49:54PM +0300, Dmitry Timoshkov wrote:
> > > +int WINAPI wWinMain(HINSTANCE hinst, HINSTANCE previnst, LPWSTR cmdline, int showcmd)
> > > +{
> > > - HRESULT hr;
> > > - CLSID clsid;
> > > -
> > > - CoInitializeEx(NULL, COINIT_MULTITHREADED);
> > > -
> > > - hr = CLSIDFromString(cmdline, &clsid);
> >
> > It looks like Windows uses the cmdline:
> >
> > dllhost.exe /PROCESSID:{GUID}
>
> MSDN's "Using the System-Supplied Surrogate" article
> https://docs.microsoft.com/en-us/windows/win32/com/using-the-system-supplied...
> and a pretty good guide for writing custom surrogate (which I follow in my work)
> https://docs.microsoft.com/en-us/windows/win32/com/writing-a-custom-surrogat...
> they both mention only "CLSID on the launch command line".
> Also the prototype patch attached to the bug
> https://bugs.winehq.org/show_bug.cgi?id=20296 
> passes just {GUID} on the command line.

Thanks for the links, I'll take a look.
> Where do you see /PROCESSID mentioned for the surrogate process context?
> Also it's not clear to me that /PROCESSID belongs to the hosted object,
> and not something else, like really some process id.

I used Process Explorer on Win 10 to look at the command-lines of some
running dllhost.exe instances.  For the one handling the thumbnail
cache, the guid matched the CLSID of the thumbnail cache server (and
besides there was nothing else on the command-line, so it had to be
that).

Also see:
https://www.howtogeek.com/326462/what-is-com-surrogate-dllhost.exe-and-why-i...
> Probably that's an internal implementation detail, and I'm open to use
> whatever is deemed to be appropriate.

Sure, but as it's easy enough to implement, I think we should follow
Windows' behaviour.

Huw.