[Qemu-devel] [PATCH for-3.1 v2] build: qga: add macro to force use of native mingw32 assert()

[Michael Roth <mdroth@linux.vnet.ibm.com>]

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 for build targets that
don't link against glib.

Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
v2:
 * define USE_NATIVE_MINGW32_ASSERT via build recipe and avoid moving
   #include's before osdep.h (Philippe)
---
 include/qemu/osdep.h        | 2 +-
 qga/vss-win32/Makefile.objs | 2 +-
 2 files changed, 2 insertions(+), 2 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
diff --git a/qga/vss-win32/Makefile.objs b/qga/vss-win32/Makefile.objs
index 23d08da225..5773bfd868 100644
--- a/qga/vss-win32/Makefile.objs
+++ b/qga/vss-win32/Makefile.objs
@@ -3,7 +3,7 @@
 qga-vss-dll-obj-y += requester.o provider.o install.o
 
 obj-qga-vss-dll-obj-y = $(addprefix $(obj)/, $(qga-vss-dll-obj-y))
-$(obj-qga-vss-dll-obj-y): QEMU_CXXFLAGS = $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls -fstack-protector-all -fstack-protector-strong, $(QEMU_CFLAGS)) -Wno-unknown-pragmas -Wno-delete-non-virtual-dtor
+$(obj-qga-vss-dll-obj-y): QEMU_CXXFLAGS = $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls -fstack-protector-all -fstack-protector-strong, $(QEMU_CFLAGS)) -Wno-unknown-pragmas -Wno-delete-non-virtual-dtor -DUSE_NATIVE_MINGW32_ASSERT
 
 $(obj)/qga-vss.dll: LDFLAGS = -shared -Wl,--add-stdcall-alias,--enable-stdcall-fixup -lole32 -loleaut32 -lshlwapi -luuid -static
 $(obj)/qga-vss.dll: $(obj-qga-vss-dll-obj-y) $(SRC_PATH)/$(obj)/qga-vss.def
-- 
2.17.1