Re: [Qemu-devel] [PATCH] build: qga: add macro to force use of native mingw32 assert()

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

Hi Michael,

On 11/9/18 5:00 PM, Michael Roth wrote:
> When building qemu-ga for w32 with VSS support, some parts of qemu-ga
> are not linked against glib, specifically the C++ bits used to
> create the VSS provider DLL. With 3ebee3b191e, we now define assert()
> as g_assert() for all mingw32 builds via osdep.h, which results in the
> following build breakage:
> 
>   x86_64-w64-mingw32-g++ -o qga/vss-win32/qga-vss.dll qga/vss-win32/requester.o qga/vss-win32/provider.o qga/vss-win32/install.o /home/mdroth/w/qemu4.git/qga/vss-win32/qga-vss.def  -shared -Wl,--add-stdcall-alias,--enable-stdcall-fixup -lole32 -loleaut32 -lshlwapi -luuid -static
>   qga/vss-win32/requester.o: In function `requester_freeze':
>   /home/mdroth/w/qemu4.git/qga/vss-win32/requester.cpp:284: undefined reference to `g_assertion_message_expr'
>   qga/vss-win32/requester.o: In function `requester_thaw':
>   /home/mdroth/w/qemu4.git/qga/vss-win32/requester.cpp:508: undefined reference to `g_assertion_message_expr'
>   /home/mdroth/w/qemu4.git/qga/vss-win32/requester.cpp:509: undefined reference to `g_assertion_message_expr'
>   collect2: error: ld returned 1 exit status
>   make: *** [/home/mdroth/w/qemu4.git/qga/vss-win32/Makefile.objs:10: qga/vss-win32/qga-vss.dll] Error 1
>   make: *** Waiting for unfinished jobs....
> 
> Fix this by introducing a USE_NATIVE_MINGW32_ASSERT macro that can
> be defined prior to inclusion of osdep.h in individual C/C++ files
> that don't link against glib.
> 
> Cc: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> ---
>  include/qemu/osdep.h        | 2 +-
>  qga/vss-win32/install.cpp   | 2 +-
>  qga/vss-win32/provider.cpp  | 2 +-
>  qga/vss-win32/requester.cpp | 2 +-
>  qga/vss-win32/vss-common.h  | 2 ++
>  5 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index 3bf48bcdec..59364bfeb0 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -129,7 +129,7 @@ extern int daemon(int, int);
>   * code that is unreachable when features are disabled.
>   * All supported versions of Glib's g_assert() satisfy this requirement.
>   */
> -#ifdef __MINGW32__
> +#if defined(__MINGW32__) && !defined(USE_NATIVE_MINGW32_ASSERT)
>  #undef assert
>  #define assert(x)  g_assert(x)
>  #endif

OK.

> diff --git a/qga/vss-win32/install.cpp b/qga/vss-win32/install.cpp
> index 6713e58670..6ed2d5930c 100644
> --- a/qga/vss-win32/install.cpp
> +++ b/qga/vss-win32/install.cpp
> @@ -10,9 +10,9 @@
>   * See the COPYING file in the top-level directory.
>   */
>  
> +#include "vss-common.h"
>  #include "qemu/osdep.h"

I don't like breaking the rule and not using "qemu/osdep.h" first.
(See below for suggestion).

>  
> -#include "vss-common.h"
>  #include <inc/win2003/vscoordint.h>
>  #include "install.h"
>  #include <wbemidl.h>
> diff --git a/qga/vss-win32/provider.cpp b/qga/vss-win32/provider.cpp
> index 72d8b0e19d..d298af91b2 100644
> --- a/qga/vss-win32/provider.cpp
> +++ b/qga/vss-win32/provider.cpp
> @@ -10,8 +10,8 @@
>   * See the COPYING file in the top-level directory.
>   */
>  
> -#include "qemu/osdep.h"
>  #include "vss-common.h"
> +#include "qemu/osdep.h"

Ditto.

>  #include <inc/win2003/vscoordint.h>
>  #include <inc/win2003/vsprov.h>
>  
> diff --git a/qga/vss-win32/requester.cpp b/qga/vss-win32/requester.cpp
> index 5378c55d23..d239bd9598 100644
> --- a/qga/vss-win32/requester.cpp
> +++ b/qga/vss-win32/requester.cpp
> @@ -10,8 +10,8 @@
>   * See the COPYING file in the top-level directory.
>   */
>  
> -#include "qemu/osdep.h"
>  #include "vss-common.h"
> +#include "qemu/osdep.h"

Ditto.

>  #include "requester.h"
>  #include "install.h"
>  #include <inc/win2003/vswriter.h>
> diff --git a/qga/vss-win32/vss-common.h b/qga/vss-win32/vss-common.h
> index 61c170b52e..275cbb59c5 100644
> --- a/qga/vss-win32/vss-common.h
> +++ b/qga/vss-win32/vss-common.h
> @@ -13,6 +13,8 @@
>  #ifndef VSS_COMMON_H
>  #define VSS_COMMON_H
>  
> +#define USE_NATIVE_MINGW32_ASSERT

I believe you can add this in the "VSS SDK" section of the ./configure
script:

-- >8 --
diff --git a/configure b/configure
@@ -4588,7 +4588,7 @@ int main(void) { return VSS_CTX_BACKUP; }
 EOF
   if compile_prog "$vss_win32_include" "" ; then
     guest_agent_with_vss="yes"
-    QEMU_CFLAGS="$QEMU_CFLAGS $vss_win32_include"
+    QEMU_CFLAGS="$QEMU_CFLAGS -DUSE_NATIVE_MINGW32_ASSERT
$vss_win32_include"
     libs_qga="-lole32 -loleaut32 -lshlwapi -lstdc++
-Wl,--enable-stdcall-fixup $libs_qga"
     qga_vss_provider="qga/vss-win32/qga-vss.dll qga/vss-win32/qga-vss.tlb"
   else
---

What do you think?

Regards,

Phil.

> +
>  #define __MIDL_user_allocate_free_DEFINED__
>  #include <windows.h>
>  #include <shlwapi.h>
>