building plugin failed on Windows with mingw

[Xiaolei]

I want to build QEMU 4.2.0's plugin module on Windows 7/10 with Mingw, but the building process faild.

The step I follow is listed below:
1. create "dsp_build" diretory under source file folder

2. change directory to dsp_build , and run ../configure --target-list=dsp-softmmu --cross-prefix=x86_64-w64-mingw32- --enable-gtk --enable-sdl --enable-debug --enable-plugins
3. build qemu project
4. switch dir to /dsp_build, make -C tests/plugin, yeilds error:
   CC bb.o
 D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:17:24: error: variable 'qemu_plugin_version' definition is marked dllimport
   17 | QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
      | ^~~~~~~~~~~~~~~~~~~
 D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:17:24: warning: 'qemu_plugin_version' redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]
 D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c: In function 'vcpu_tb_exec':
 D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:33:29: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
   33 | unsigned long n_insns = (unsigned long)udata;
      | ^
 D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c: In function 'vcpu_tb_trans':
 D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:51:46: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   51 | (void *)n_insns);

5. Then , I modified the QEMU_flags and the compilation command arguments($(CC) ..) in the makefile :

  BUILD_DIR := $(CURDIR)/../..

  include $(BUILD_DIR)/config-host.mak
  include $(SRC_PATH)/rules.mak

  $(call set-vpath, $(SRC_PATH)/tests/plugin)

  NAMES :=
  NAMES += bb
  NAMES += empty
  NAMES += insn
  NAMES += mem
  NAMES += hotblocks
  NAMES += howvec
  NAMES += hotpages

  SONAMES := $(addsuffix .so,$(addprefix lib,$(NAMES)))

  QEMU_CFLAGS += -fPIC -DBUILDING_DLL #added -DBUILDING_DLL
  QEMU_CFLAGS += -I$(SRC_PATH)/include/qemu

  all: $(SONAMES)

  lib%.so: %.o
   $(CC) -fPIC -shared -o $@ $^ $(LDLIBS) -L /c/msys64/mingw64/lib/ -lglib-2.0
   # original cmd: $(CC) -shared -Wl,-soname,$@ -o $@ $^ $(LDLIBS)

  clean:
   rm -f *.o *.so *.d
   rm -Rf .libs

  .PHONY: all clean

6. Executing make yeilds:

make: enter “/d/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/build_dsp/tests/plugin”
  CC bb.o
x86_64-w64-mingw32-gcc -fPIC -shared -o libbb.so bb.o -L /c/msys64/mingw64/lib/ -lglib-2.0
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `plugin_exit':
D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:28: undefined reference to `qemu_plugin_outs'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:29: undefined reference to `__stack_chk_fail'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `vcpu_tb_trans':
D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:41: undefined reference to `qemu_plugin_tb_n_insns'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:44: undefined reference to `qemu_plugin_register_vcpu_tb_exec_inline'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:46: undefined reference to `qemu_plugin_register_vcpu_tb_exec_inline'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:49: undefined reference to `qemu_plugin_register_vcpu_tb_exec_cb'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `qemu_plugin_install':
D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:63: undefined reference to `qemu_plugin_register_vcpu_tb_trans_cb'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/emu_devl/qemu_src/qemu-sr-dsp-a/qemu_tidsp_c3x/tests/plugin/bb.c:64: undefined reference to `qemu_plugin_register_atexit_cb'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o:bb.c:(.rdata$.refptr.__stack_chk_guard[.refptr.__stack_chk_guard]+0x0): undefined reference to `__stack_chk_guard'
collect2.exe: error: ld returned 1 exit status

   It looks like linking problem(fail to link functions defined in api.c, core.c...), but I have no idea what goes wrong. If I mannualy add api.o, core.o in the compilation command, still get error like undefined reference to '__stack_chk_guard'.
   My collegue can build 4.2.0 plugins on Ubuntu Linux without any problem.

[Xiaolei (casmac)]

    If I keep "-Wl,-soname,$@" in the command , I got similar linking errors.

makefile:
SONAMES := $(addsuffix .dll,$(addprefix lib,$(NAMES)))

QEMU_CFLAGS += -fPIC -fno-stack-protector -DBUILDING_DLL
QEMU_CFLAGS += -I$(SRC_PATH)/include/qemu

all: $(SONAMES)
lib%.dll: %.o
    $(CC) -shared -Wl,-soname,$@ -o $@ $^ $(LDLIBS)

output:
x86_64-w64-mingw32-gcc -shared -Wl,-soname,libbb.dll -o libbb.dll bb.o
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `g_autoptr_cleanup_generic_gfree':
C:/msys64/mingw64/include/glib-2.0/glib/glib-autocleanups.h:28: undefined reference to `g_free'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `plugin_exit':
C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:27: undefined reference to `g_strdup_printf'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:29: undefined reference to `qemu_plugin_outs'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `vcpu_tb_trans':
C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:42: undefined reference to `qemu_plugin_tb_n_insns'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:45: undefined reference to `qemu_plugin_register_vcpu_tb_exec_inline'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:47: undefined reference to `qemu_plugin_register_vcpu_tb_exec_inline'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:50: undefined reference to `qemu_plugin_register_vcpu_tb_exec_cb'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `qemu_plugin_install':
C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:64: undefined reference to `qemu_plugin_register_vcpu_tb_trans_cb'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:65: undefined reference to `qemu_plugin_register_atexit_cb'
collect2.exe: error: ld returned 1 exit status

    On windows, I replace $LDLIBS with $LIBS here, because $LDLIBS seems undefined. But still yields linking error, except.
     lib%.dll: %.o
       $(CC) -shared -Wl,-soname,$@ -o $@ $^ $(LIBS)"

x86_64-w64-mingw32-gcc -shared -Wl,-soname,libbb.dll -o libbb.dll bb.o -ldl -LC:/msys64/mingw64/lib -lz -LC:/msys64/mingw64/lib -lgmodule-2.0 -pthread -lglib-2.0 -lintl -LC:/msys64/mingw64/lib -lgthread-2.0 -pthread -lglib-2.0 -lintl -lwinmm -lws2_32 -liphlpapi
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `plugin_exit':
C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:29: undefined reference to `qemu_plugin_outs'
C...

[Alex Bennée (ajbennee)]

Xiaolei <email address hidden> writes:

> If I keep "-Wl,-soname,$@" in the command , I got similar linking errors.
>
> makefile:
> SONAMES := $(addsuffix .dll,$(addprefix lib,$(NAMES)))
>
> QEMU_CFLAGS += -fPIC -fno-stack-protector -DBUILDING_DLL
> QEMU_CFLAGS += -I$(SRC_PATH)/include/qemu
>
> all: $(SONAMES)
> lib%.dll: %.o
> $(CC) -shared -Wl,-soname,$@ -o $@ $^ $(LDLIBS)
>
> output:
> x86_64-w64-mingw32-gcc -shared -Wl,-soname,libbb.dll -o libbb.dll bb.o
> C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `g_autoptr_cleanup_generic_gfree':
> C:/msys64/mingw64/include/glib-2.0/glib/glib-autocleanups.h:28: undefined reference to `g_free'
> C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `plugin_exit':
> C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:27: undefined reference to `g_strdup_printf'
> C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:29: undefined reference to `qemu_plugin_outs'
> C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `vcpu_tb_trans':
> C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:42: undefined reference to `qemu_plugin_tb_n_insns'
> C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:45: undefined reference to `qemu_plugin_register_vcpu_tb_exec_inline'
> C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:47: undefined reference to `qemu_plugin_register_vcpu_tb_exec_inline'
> C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:50: undefined reference to `qemu_plugin_register_vcpu_tb_exec_cb'
> C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `qemu_plugin_install':
> C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:64: undefined reference to `qemu_plugin_register_vcpu_tb_trans_cb'
> C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:65: undefined reference to `qemu_plugin_register_atexit_cb'
> collect2.exe: error: ld returned 1 exit status

Cc'ing Emilio as he wrote the initial code so I assume built it at one point.

--
Alex Bennée

[Emilio G. Cota (cota)]

I never built the plugin code on anything other than Linux :(
All I did for Windows is to try to follow https://gcc.gnu.org/wiki/Visibility

Can you please try the following patch (with no other changes)?
The patch applies on top of v4.2.0.

diff --git a/tests/plugin/Makefile b/tests/plugin/Makefile
index 75467b6db8..5b3611ad63 100644
--- a/tests/plugin/Makefile
+++ b/tests/plugin/Makefile
@@ -16,7 +16,7 @@ NAMES += hotpages

 SONAMES := $(addsuffix .so,$(addprefix lib,$(NAMES)))

-QEMU_CFLAGS += -fPIC
+QEMU_CFLAGS += -fPIC -DBUILDING_DLL
 QEMU_CFLAGS += -I$(SRC_PATH)/include/qemu

 all: $(SONAMES)

[Emilio G. Cota (cota)]

Xiaolei confirmed to me via email that adding -DBUILDING_DLL is not enough to fix the problem.

I looked into this a bit further and it looks like we need an "import library" to be created when compiling the QEMU binary. This is accomplished by adding "-Wl,--out-implib,libqemu_plugin.a" to the linker invocation to build the QEMU binary. See these two stackoverflow questions:
- https://stackoverflow.com/questions/17601949/building-a-shared-library-using-gcc-on-linux-and-mingw-on-windows
- https://stackoverflow.com/questions/39759060/compile-to-dll-with-some-undefined-references-with-mingw

It's not clear to me whether any import library with the symbols needed can work, or whether each target binary needs its corresponding import library, e.g. aarch64-linux-user and x86_64-linux-user need different libraries. The below is an attempt at the latter approach; one would just have to link the appropriate import library with "-l" when building the plugin.

Please give this a try, and don't forget to also pass -DBUILDING_DLL to the linker.

diff --git a/Makefile b/Makefile
index b437a346d7..5cc1bc8e23 100644
--- a/Makefile
+++ b/Makefile
@@ -866,8 +866,14 @@ ICON_SIZES=16x16 24x24 32x32 48x48 64x64 128x128 256x256 512x512
 install-includedir:
        $(INSTALL_DIR) "$(DESTDIR)$(includedir)"

+install-libdir:
+ $(INSTALL_DIR) "$(DESTDIR)$(libdir)"
+ for d in $(TARGET_DIRS); do \
+ $(INSTALL_DIR) "$(DESTDIR)$(libdir)/$$d"; \
+ done
+
 install: all $(if $(BUILD_DOCS),install-doc) \
- install-datadir install-localstatedir install-includedir \
+ install-datadir install-localstatedir install-includedir install-libdir \
        $(if $(INSTALL_BLOBS),$(edk2-decompressed)) \
        recurse-install
 ifneq ($(TOOLS),)
@@ -932,6 +938,11 @@ ifdef CONFIG_GTK
 endif
 ifeq ($(CONFIG_PLUGIN),y)
        $(INSTALL_DATA) $(SRC_PATH)/include/qemu/qemu-plugin.h "$(DESTDIR)$(includedir)/qemu-plugin.h"
+# ifeq MINGW, WINDOWS or similar.
+ for d in $(TARGET_DIRS); do \
+ $(INSTALL_DATA) "$$d/libqemu_plugin.dll.a" "$(DESTDIR)$(libdir)/$$d/libqemu_plugin.dll.a"; \
+ done
+# endif
 endif
        $(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)/keymaps"
        set -e; for x in $(KEYMAPS); do \
diff --git a/configure b/configure
index 6099be1d84..9606f6e888 100755
--- a/configure
+++ b/configure
@@ -7455,6 +7455,9 @@ if test "$plugins" = "yes" ; then
            "If \$plugins=yes, either \$ld_dynamic_list or " \
            "\$ld_exported_symbols_list should have been set to 'yes'."
     fi
+ # if test "$mingw32" = "yes" ; then # or mingw, or windows; I don't know.
+ QEMU_LDFLAGS="-Wl,--out-implib,libqemu_plugin.dll.a"
+ # fi
 fi

 if test "$tcg_interpreter" = "yes"; then

[Xiaolei (casmac)]

Hi,
  I patched configure file and makefile. The output is listed below.
  The project is configured as :
  #../configure --target-list=dsp-softmmu --cross-prefix=x86_64-w64-mingw32- --enable-gtk --enable-sdl --enable-debug --enable-plugins --extra-cflags="-DBUILDING_DLL"

  But running make yeilds error:
  CC dsp-softmmu/trace/generated-helpers.o
  CC dsp-softmmu/trace/control-target.o
  LINK dsp-softmmu/qemu-system-dspw.exe
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: cannot find -lfdt
collect2.exe: error: ld returned 1 exit status
make[1]: *** [Makefile:208: qemu-system-dspw.exe] Error 1
make: *** [Makefile:491: dsp-softmmu/all] Error 2

  We then reconfigured by disable the -fdt :
  ../configure --target-list=dsp-softmmu --cross-prefix=x86_64-w64-mingw32- --enable-gtk --enable-sdl --enable-debug --enable-plugins --disable-fdt --extra-cflags="-DBUILDING_DLL"
  Build finished and running "make -C tests/plugin" gets similar linking errors:

  x86_64-w64-mingw32-gcc -shared -Wl,-soname,libbb.so -o libbb.so bb.o
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `g_autoptr_cleanup_generic_gfree':
C:/msys64/mingw64/include/glib-2.0/glib/glib-autocleanups.h:28: undefined reference to `g_free'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `plugin_exit':
C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:27: undefined reference to `g_strdup_printf'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:29: undefined reference to `qemu_plugin_outs'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:30: undefined reference to `__stack_chk_fail'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `vcpu_tb_trans':
C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:42: undefined reference to `qemu_plugin_tb_n_insns'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:45: undefined reference to `qemu_plugin_register_vcpu_tb_exec_inline'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:47: undefined reference to `qemu_plugin_register_vcpu_tb_exec_inline'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:50: undefined reference to `qemu_plugin_register_vcpu_tb_exec_cb'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: bb.o: in function `qemu_plugin_install':
C:/QRS_Project/simdsp/qemu-4.2.0/tests/plugin/bb.c:64: undefined reference to `qemu_plugin_register_vcpu_tb_trans_cb'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/.....

[Emilio G. Cota (cota)]

You're getting close.

1. From the build directory, find the import library created, e.g. `find . -name 'libqemu_plugin.dll.a'`. If you're building x86_64-linux-user, it should be in `x86_64-linux-user/libqemu_plugin.dll.a`.

2. Go back to the `build/tests/plugin` directory.

3. Link the empty plugin with:
x86_64-w64-mingw32-gcc -shared -Wl,-soname,libempty.so -o libempty.so empty.o -L/path/to/libqemu_plugin.dll.a/directory -lqemu_plugin.dll

Note the added -L and -l flags.

If that works, move on to the other plugins, although you might have to comment out the glib-dependent code. But let's not go there yet; try to build the empty plugin first.

[Xiaolei (casmac)]

Hi Emilio,
  I got the ideas for the attempt with a dummy dll. However, my collegue and I both failed to generate libqemu_plugin.dll.a during make process.
  And running "make install" yields errors as follows:

mkdir -p "C:/QEMU_install/QEMUa/applications"
install -c -m 0644 /c/QRS_Project/simdsp/qemu-4.2.0/ui/qemu.desktop \
        "C:/QEMU_install/QEMUa/applications/qemu.desktop"
make -C po install
make[1]: enter “/c/QRS_Project/simdsp/qemu-4.2.0/dsp_debug/po”
for obj in bg.mo de_DE.mo fr_FR.mo hu.mo it.mo tr.mo zh_CN.mo; do \
    base=$(basename $obj .mo); \
    install -d C:/QEMU_install/QEMUa/share/locale/$base/LC_MESSAGES; \
    install -m644 $obj C:/QEMU_install/QEMUa/share/locale/$base/LC_MESSAGES/qemu.mo; \
done
make[1]: leave “/c/QRS_Project/simdsp/qemu-4.2.0/dsp_debug/po”
install -c -m 0644 /c/QRS_Project/simdsp/qemu-4.2.0/include/qemu/qemu-plugin.h "C:/QEMU_install/QEMUa/include/qemu-plugin.h"
for d in dsp-softmmu; do \
        install -c -m 0644 "$d/libqemu_plugin.dll.a" "C:/QEMU_install/QEMUa/lib/$d/libqemu_plugin.dll.a"; \
done
install: unable to get 'dsp-softmmu/libqemu_plugin.dll.a' file status (stat): No such file or directory
make: *** [Makefile:890：install] error 1
   Any ideas?

[Emilio G. Cota (cota)]

You should then find out why libqemu_plugin.dll.a is not working. It is possible though that your linked is calling the import library something else, for instance adding a .dll extension to it.

You will have to run a few tests with your linker (I'd just use the examples from the stackoverflow links I posted above) to see the name of the import library that gets created. My assumption is that some library gets created, otherwise the linked should give you an error and AFAICT it does not.

Once you find what the import library us, you should be in good shape to adapt the above for QEMU. Let us know how it goes!

[Alex Bennée (ajbennee)]

Emilio G. Cota <email address hidden> writes:

> You should then find out why libqemu_plugin.dll.a is not working. It is
> possible though that your linked is calling the import library something
> else, for instance adding a .dll extension to it.
>
> You will have to run a few tests with your linker (I'd just use the
> examples from the stackoverflow links I posted above) to see the name of
> the import library that gets created. My assumption is that some library
> gets created, otherwise the linked should give you an error and AFAICT
> it does not.
>
> Once you find what the import library us, you should be in good shape to
> adapt the above for QEMU. Let us know how it goes!

I did have a go but couldn't get far with the mingw docker images. I got
somewhat distracted yesterday solving the mysterious regenerating
syscall_nr.h problem so I've run out of bandwidth to look at this any
longer. If the two of you find an eventual solution please send me a
patch.

Thanks.

--
Alex Bennée

[Thomas Huth (th-huth)]

The QEMU project is currently moving its bug tracking to another system.
For this we need to know which bugs are still valid and which could be
closed already. Thus we are setting the bug state to "Incomplete" now.

If the bug has already been fixed in the latest upstream version of QEMU,
then please close this ticket as "Fix released".

If it is not fixed yet and you think that this bug report here is still
valid, then you have two options:

1) If you already have an account on gitlab.com, please open a new ticket
for this problem in our new tracker here:

    https://gitlab.com/qemu-project/qemu/-/issues

and then close this ticket here on Launchpad (or let it expire auto-
matically after 60 days). Please mention the URL of this bug ticket on
Launchpad in the new ticket on GitLab.

2) If you don't have an account on gitlab.com and don't intend to get
one, but still would like to keep this ticket opened, then please switch
the state back to "New" within the next 60 days (otherwise it will get
closed as "Expired"). We will then eventually migrate the ticket auto-
matically to the new system (but you won't be the reporter of the bug
in the new system and thus won't get notified on changes anymore).

Thank you and sorry for the inconvenience.

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]