| Message ID | 20230830161425.91946-2-graf@amazon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce new vmapple machine type | expand |
On 30/8/23 18:14, Alexander Graf wrote: > Recent versions of macOS use clang instead of gcc. The OS_OBJECT_USE_OBJC > define is only necessary when building with gcc. Let's not define it when > building with clang. > > With this patch, I can successfully include GCD headers in QEMU when > building with clang. > > Signed-off-by: Alexander Graf <graf@amazon.com> > --- > meson.build | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/meson.build b/meson.build > index 98e68ef0b1..0d6a0015a1 100644 > --- a/meson.build > +++ b/meson.build > @@ -224,7 +224,9 @@ qemu_ldflags = [] > if targetos == 'darwin' > # Disable attempts to use ObjectiveC features in os/object.h since they > # won't work when we're compiling with gcc as a C compiler. > - qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' > + if compiler.get_id() == 'gcc' > + qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' > + endif > elif targetos == 'solaris' > # needed for CMSG_ macros in sys/socket.h > qemu_common_flags += '-D_XOPEN_SOURCE=600' Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
On 2023/08/31 17:12, Philippe Mathieu-Daudé wrote: > On 30/8/23 18:14, Alexander Graf wrote: >> Recent versions of macOS use clang instead of gcc. The OS_OBJECT_USE_OBJC >> define is only necessary when building with gcc. Let's not define it when >> building with clang. >> >> With this patch, I can successfully include GCD headers in QEMU when >> building with clang. >> >> Signed-off-by: Alexander Graf <graf@amazon.com> >> --- >> meson.build | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/meson.build b/meson.build >> index 98e68ef0b1..0d6a0015a1 100644 >> --- a/meson.build >> +++ b/meson.build >> @@ -224,7 +224,9 @@ qemu_ldflags = [] >> if targetos == 'darwin' >> # Disable attempts to use ObjectiveC features in os/object.h since >> they >> # won't work when we're compiling with gcc as a C compiler. >> - qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' >> + if compiler.get_id() == 'gcc' >> + qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' >> + endif >> elif targetos == 'solaris' >> # needed for CMSG_ macros in sys/socket.h >> qemu_common_flags += '-D_XOPEN_SOURCE=600' > > Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> > Defining OS_OBJECT_USE_OBJC does not look like a proper solution. Looking at os/object.h, it seems OS_OBJECT_USE_OBJC is defined as 0 when: !defined(OS_OBJECT_HAVE_OBJC_SUPPORT) && (!defined(__OBJC__) || defined(__OBJC_GC__)) This means OS_OBJECT_USE_OBJC is always 0 if Objective-C is disabled. I also confirmed os/object.h will not use Objective-C features when compiled as C code on clang with the following command: clang -E -x -c - <<EOF #include <os/object.h> EOF If compilation fails with GCC when not defining OS_OBJECT_USE_OBJC, it probably means GCC incorrectly treats C code as Objective-C and that is the problem we should solve. I cannot confirm this theory however since I have only an Apple Silicon Mac that is incompatible with GCC. Regards, Akihiko Odaki
On 31.08.23 10:53, Akihiko Odaki wrote: > > > On 2023/08/31 17:12, Philippe Mathieu-Daudé wrote: >> On 30/8/23 18:14, Alexander Graf wrote: >>> Recent versions of macOS use clang instead of gcc. The >>> OS_OBJECT_USE_OBJC >>> define is only necessary when building with gcc. Let's not define it >>> when >>> building with clang. >>> >>> With this patch, I can successfully include GCD headers in QEMU when >>> building with clang. >>> >>> Signed-off-by: Alexander Graf <graf@amazon.com> >>> --- >>> meson.build | 4 +++- >>> 1 file changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/meson.build b/meson.build >>> index 98e68ef0b1..0d6a0015a1 100644 >>> --- a/meson.build >>> +++ b/meson.build >>> @@ -224,7 +224,9 @@ qemu_ldflags = [] >>> if targetos == 'darwin' >>> # Disable attempts to use ObjectiveC features in os/object.h since >>> they >>> # won't work when we're compiling with gcc as a C compiler. >>> - qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' >>> + if compiler.get_id() == 'gcc' >>> + qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' >>> + endif >>> elif targetos == 'solaris' >>> # needed for CMSG_ macros in sys/socket.h >>> qemu_common_flags += '-D_XOPEN_SOURCE=600' >> >> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> >> > > Defining OS_OBJECT_USE_OBJC does not look like a proper solution. > Looking at os/object.h, it seems OS_OBJECT_USE_OBJC is defined as 0 when: > !defined(OS_OBJECT_HAVE_OBJC_SUPPORT) && (!defined(__OBJC__) || > defined(__OBJC_GC__)) > > This means OS_OBJECT_USE_OBJC is always 0 if Objective-C is disabled. I > also confirmed os/object.h will not use Objective-C features when > compiled as C code on clang with the following command: > > clang -E -x -c - <<EOF > #include <os/object.h> > EOF > > If compilation fails with GCC when not defining OS_OBJECT_USE_OBJC, it > probably means GCC incorrectly treats C code as Objective-C and that is > the problem we should solve. I cannot confirm this theory however since > I have only an Apple Silicon Mac that is incompatible with GCC. My take on this was to make the gcc hack be a "legacy" thing that we put into its own corner, so that in a few years we can just drop it altogether. I don't really think it's worth wasting much time on this workaround and its potential compatibility with old macOS versions. Alex Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B Sitz: Berlin Ust-ID: DE 289 237 879
On 2023/08/31 17:59, Alexander Graf wrote: > > On 31.08.23 10:53, Akihiko Odaki wrote: >> >> >> On 2023/08/31 17:12, Philippe Mathieu-Daudé wrote: >>> On 30/8/23 18:14, Alexander Graf wrote: >>>> Recent versions of macOS use clang instead of gcc. The >>>> OS_OBJECT_USE_OBJC >>>> define is only necessary when building with gcc. Let's not define it >>>> when >>>> building with clang. >>>> >>>> With this patch, I can successfully include GCD headers in QEMU when >>>> building with clang. >>>> >>>> Signed-off-by: Alexander Graf <graf@amazon.com> >>>> --- >>>> meson.build | 4 +++- >>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/meson.build b/meson.build >>>> index 98e68ef0b1..0d6a0015a1 100644 >>>> --- a/meson.build >>>> +++ b/meson.build >>>> @@ -224,7 +224,9 @@ qemu_ldflags = [] >>>> if targetos == 'darwin' >>>> # Disable attempts to use ObjectiveC features in os/object.h since >>>> they >>>> # won't work when we're compiling with gcc as a C compiler. >>>> - qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' >>>> + if compiler.get_id() == 'gcc' >>>> + qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' >>>> + endif >>>> elif targetos == 'solaris' >>>> # needed for CMSG_ macros in sys/socket.h >>>> qemu_common_flags += '-D_XOPEN_SOURCE=600' >>> >>> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> >>> >> >> Defining OS_OBJECT_USE_OBJC does not look like a proper solution. >> Looking at os/object.h, it seems OS_OBJECT_USE_OBJC is defined as 0 when: >> !defined(OS_OBJECT_HAVE_OBJC_SUPPORT) && (!defined(__OBJC__) || >> defined(__OBJC_GC__)) >> >> This means OS_OBJECT_USE_OBJC is always 0 if Objective-C is disabled. I >> also confirmed os/object.h will not use Objective-C features when >> compiled as C code on clang with the following command: >> >> clang -E -x -c - <<EOF >> #include <os/object.h> >> EOF >> >> If compilation fails with GCC when not defining OS_OBJECT_USE_OBJC, it >> probably means GCC incorrectly treats C code as Objective-C and that is >> the problem we should solve. I cannot confirm this theory however since >> I have only an Apple Silicon Mac that is incompatible with GCC. > > > My take on this was to make the gcc hack be a "legacy" thing that we put > into its own corner, so that in a few years we can just drop it > altogether. I don't really think it's worth wasting much time on this > workaround and its potential compatibility with old macOS versions. That makes sense. Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
diff --git a/meson.build b/meson.build index 98e68ef0b1..0d6a0015a1 100644 --- a/meson.build +++ b/meson.build @@ -224,7 +224,9 @@ qemu_ldflags = [] if targetos == 'darwin' # Disable attempts to use ObjectiveC features in os/object.h since they # won't work when we're compiling with gcc as a C compiler. - qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' + if compiler.get_id() == 'gcc' + qemu_common_flags += '-DOS_OBJECT_USE_OBJC=0' + endif elif targetos == 'solaris' # needed for CMSG_ macros in sys/socket.h qemu_common_flags += '-D_XOPEN_SOURCE=600'
Recent versions of macOS use clang instead of gcc. The OS_OBJECT_USE_OBJC define is only necessary when building with gcc. Let's not define it when building with clang. With this patch, I can successfully include GCD headers in QEMU when building with clang. Signed-off-by: Alexander Graf <graf@amazon.com> --- meson.build | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)