| Message ID | 20241128201510.869974-4-pierrick.bouvier@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Enable clang build on Windows | expand |
+Akihiko & Yonggang for https://lore.kernel.org/qemu-devel/20201006120900.1579-1-luoyonggang@gmail.com/ On 28/11/24 21:15, Pierrick Bouvier wrote: > Windows uses a special mechanism to enable plugins to work (DLL delay > loading). Option for lld is different than ld. > > MSYS2 clang based environment use lld by default, so restricting to this > config on Windows is safe, and will avoid false bug reports. > > Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> > --- > meson.build | 5 +++++ > contrib/plugins/meson.build | 2 +- > plugins/meson.build | 24 ++++++++++++++++++++---- > tests/tcg/plugins/meson.build | 3 +-- > 4 files changed, 27 insertions(+), 7 deletions(-) > > diff --git a/meson.build b/meson.build > index 97cefb7cdd7..f286fb4f4a0 100644 > --- a/meson.build > +++ b/meson.build > @@ -354,6 +354,11 @@ elif host_os == 'sunos' > qemu_common_flags += '-D__EXTENSIONS__' > elif host_os == 'haiku' > qemu_common_flags += ['-DB_USE_POSITIVE_POSIX_ERRORS', '-D_BSD_SOURCE', '-fPIC'] > +elif host_os == 'windows' > + # plugins use delaylib, and clang needs to be used with lld to make it work. > + if compiler.get_id() == 'clang' and compiler.get_linker_id() != 'ld.lld' > + error('On windows, you need to use lld with clang - use msys2 clang64/clangarm64 env') > + endif > endif > > # Choose instruction set (currently x86-only) > diff --git a/contrib/plugins/meson.build b/contrib/plugins/meson.build > index 63a32c2b4f0..484b9a808c8 100644 > --- a/contrib/plugins/meson.build > +++ b/contrib/plugins/meson.build > @@ -12,7 +12,7 @@ if get_option('plugins') > t += shared_module(i, files(i + '.c') + 'win32_linker.c', > include_directories: '../../include/qemu', > link_depends: [win32_qemu_plugin_api_lib], > - link_args: ['-Lplugins', '-lqemu_plugin_api'], > + link_args: win32_qemu_plugin_api_link_flags, > dependencies: glib) > else > t += shared_module(i, files(i + '.c'), > diff --git a/plugins/meson.build b/plugins/meson.build > index 98542e926f8..d60be2a4d6d 100644 > --- a/plugins/meson.build > +++ b/plugins/meson.build > @@ -17,14 +17,15 @@ if not enable_modules > capture: true, > command: ['sed', '-ne', 's/^[[:space:]]*\\(qemu_.*\\);/_\\1/p', '@INPUT@']) > emulator_link_args += ['-Wl,-exported_symbols_list,plugins/qemu-plugins-ld64.symbols'] > + elif host_os == 'windows' and meson.get_compiler('c').get_id() == 'clang' > + # LLVM/lld does not support exporting specific symbols. However, it works > + # out of the box with dllexport/dllimport attribute we set in the code. > else > emulator_link_args += ['-Xlinker', '--dynamic-list=' + qemu_plugin_symbols.full_path()] > endif > endif > > if host_os == 'windows' > - dlltool = find_program('dlltool', required: true) > - > # Generate a .lib file for plugins to link against. > # First, create a .def file listing all the symbols a plugin should expect to have > # available in qemu > @@ -33,12 +34,27 @@ if host_os == 'windows' > output: 'qemu_plugin_api.def', > capture: true, > command: ['sed', '-e', '0,/^/s//EXPORTS/; s/[{};]//g', '@INPUT@']) > + > # then use dlltool to assemble a delaylib. > + # The delaylib will have an "imaginary" name (qemu.exe), that is used by the > + # linker file we add with plugins (win32_linker.c) to identify that we want > + # to find missing symbols in current program. > + win32_qemu_plugin_api_link_flags = ['-Lplugins', '-lqemu_plugin_api'] > + if meson.get_compiler('c').get_id() == 'clang' > + # With LLVM/lld, delaylib is specified at link time (-delayload) > + dlltool = find_program('llvm-dlltool', required: true) > + dlltool_cmd = [dlltool, '-d', '@INPUT@', '-l', '@OUTPUT@', '-D', 'qemu.exe'] > + win32_qemu_plugin_api_link_flags += ['-Wl,-delayload=qemu.exe'] > + else > + # With gcc/ld, delay lib is built with a specific delay parameter. > + dlltool = find_program('dlltool', required: true) > + dlltool_cmd = [dlltool, '--input-def', '@INPUT@', > + '--output-delaylib', '@OUTPUT@', '--dllname', 'qemu.exe'] > + endif > win32_qemu_plugin_api_lib = configure_file( > input: win32_plugin_def, > output: 'libqemu_plugin_api.a', > - command: [dlltool, '--input-def', '@INPUT@', > - '--output-delaylib', '@OUTPUT@', '--dllname', 'qemu.exe'] > + command: dlltool_cmd > ) > endif > specific_ss.add(files( > diff --git a/tests/tcg/plugins/meson.build b/tests/tcg/plugins/meson.build > index f847849b1b7..87a17d67bd4 100644 > --- a/tests/tcg/plugins/meson.build > +++ b/tests/tcg/plugins/meson.build > @@ -5,9 +5,8 @@ if get_option('plugins') > t += shared_module(i, files(i + '.c') + '../../../contrib/plugins/win32_linker.c', > include_directories: '../../../include/qemu', > link_depends: [win32_qemu_plugin_api_lib], > - link_args: ['-Lplugins', '-lqemu_plugin_api'], > + link_args: win32_qemu_plugin_api_link_flags, > dependencies: glib) > - > else > t += shared_module(i, files(i + '.c'), > include_directories: '../../../include/qemu',
diff --git a/meson.build b/meson.build index 97cefb7cdd7..f286fb4f4a0 100644 --- a/meson.build +++ b/meson.build @@ -354,6 +354,11 @@ elif host_os == 'sunos' qemu_common_flags += '-D__EXTENSIONS__' elif host_os == 'haiku' qemu_common_flags += ['-DB_USE_POSITIVE_POSIX_ERRORS', '-D_BSD_SOURCE', '-fPIC'] +elif host_os == 'windows' + # plugins use delaylib, and clang needs to be used with lld to make it work. + if compiler.get_id() == 'clang' and compiler.get_linker_id() != 'ld.lld' + error('On windows, you need to use lld with clang - use msys2 clang64/clangarm64 env') + endif endif # Choose instruction set (currently x86-only) diff --git a/contrib/plugins/meson.build b/contrib/plugins/meson.build index 63a32c2b4f0..484b9a808c8 100644 --- a/contrib/plugins/meson.build +++ b/contrib/plugins/meson.build @@ -12,7 +12,7 @@ if get_option('plugins') t += shared_module(i, files(i + '.c') + 'win32_linker.c', include_directories: '../../include/qemu', link_depends: [win32_qemu_plugin_api_lib], - link_args: ['-Lplugins', '-lqemu_plugin_api'], + link_args: win32_qemu_plugin_api_link_flags, dependencies: glib) else t += shared_module(i, files(i + '.c'), diff --git a/plugins/meson.build b/plugins/meson.build index 98542e926f8..d60be2a4d6d 100644 --- a/plugins/meson.build +++ b/plugins/meson.build @@ -17,14 +17,15 @@ if not enable_modules capture: true, command: ['sed', '-ne', 's/^[[:space:]]*\\(qemu_.*\\);/_\\1/p', '@INPUT@']) emulator_link_args += ['-Wl,-exported_symbols_list,plugins/qemu-plugins-ld64.symbols'] + elif host_os == 'windows' and meson.get_compiler('c').get_id() == 'clang' + # LLVM/lld does not support exporting specific symbols. However, it works + # out of the box with dllexport/dllimport attribute we set in the code. else emulator_link_args += ['-Xlinker', '--dynamic-list=' + qemu_plugin_symbols.full_path()] endif endif if host_os == 'windows' - dlltool = find_program('dlltool', required: true) - # Generate a .lib file for plugins to link against. # First, create a .def file listing all the symbols a plugin should expect to have # available in qemu @@ -33,12 +34,27 @@ if host_os == 'windows' output: 'qemu_plugin_api.def', capture: true, command: ['sed', '-e', '0,/^/s//EXPORTS/; s/[{};]//g', '@INPUT@']) + # then use dlltool to assemble a delaylib. + # The delaylib will have an "imaginary" name (qemu.exe), that is used by the + # linker file we add with plugins (win32_linker.c) to identify that we want + # to find missing symbols in current program. + win32_qemu_plugin_api_link_flags = ['-Lplugins', '-lqemu_plugin_api'] + if meson.get_compiler('c').get_id() == 'clang' + # With LLVM/lld, delaylib is specified at link time (-delayload) + dlltool = find_program('llvm-dlltool', required: true) + dlltool_cmd = [dlltool, '-d', '@INPUT@', '-l', '@OUTPUT@', '-D', 'qemu.exe'] + win32_qemu_plugin_api_link_flags += ['-Wl,-delayload=qemu.exe'] + else + # With gcc/ld, delay lib is built with a specific delay parameter. + dlltool = find_program('dlltool', required: true) + dlltool_cmd = [dlltool, '--input-def', '@INPUT@', + '--output-delaylib', '@OUTPUT@', '--dllname', 'qemu.exe'] + endif win32_qemu_plugin_api_lib = configure_file( input: win32_plugin_def, output: 'libqemu_plugin_api.a', - command: [dlltool, '--input-def', '@INPUT@', - '--output-delaylib', '@OUTPUT@', '--dllname', 'qemu.exe'] + command: dlltool_cmd ) endif specific_ss.add(files( diff --git a/tests/tcg/plugins/meson.build b/tests/tcg/plugins/meson.build index f847849b1b7..87a17d67bd4 100644 --- a/tests/tcg/plugins/meson.build +++ b/tests/tcg/plugins/meson.build @@ -5,9 +5,8 @@ if get_option('plugins') t += shared_module(i, files(i + '.c') + '../../../contrib/plugins/win32_linker.c', include_directories: '../../../include/qemu', link_depends: [win32_qemu_plugin_api_lib], - link_args: ['-Lplugins', '-lqemu_plugin_api'], + link_args: win32_qemu_plugin_api_link_flags, dependencies: glib) - else t += shared_module(i, files(i + '.c'), include_directories: '../../../include/qemu',
Windows uses a special mechanism to enable plugins to work (DLL delay loading). Option for lld is different than ld. MSYS2 clang based environment use lld by default, so restricting to this config on Windows is safe, and will avoid false bug reports. Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> --- meson.build | 5 +++++ contrib/plugins/meson.build | 2 +- plugins/meson.build | 24 ++++++++++++++++++++---- tests/tcg/plugins/meson.build | 3 +-- 4 files changed, 27 insertions(+), 7 deletions(-)