[Qemu-devel] [PATCH 0/2] Fix compilation on MacOS X 10.8 ("Mountain Lion")

[Qemu-devel] [PATCH 0/2] Fix compilation on MacOS X 10.8 ("Mountain Lion")

[Peter Maydell]

I had a go at compiling on my Macbook, which runs Apple's most recent
cat. I had to fix a couple of issues, which I think are down to new
stuff in the system headers:
 * the os/object.h header will try to use Objective-C syntax unless
   explicitly squashed
 * some of the headers we use in the cocoa ui frontend use the
   'Blocks' Apple extension, so won't build except with clang or
   the (now rapidly aging) Apple gcc, so to do a build with a
   modern gcc we need to support specifying the Objective-C compiler
   separately.

Peter Maydell (2):
  configure: Define OS_OBJECT_USE_OBJC=0 for MacOSX builds
  Support using a different compiler for Objective-C files

 configure | 15 +++++++++++++++
 rules.mak |  2 +-
 2 files changed, 16 insertions(+), 1 deletion(-)

-- 
1.7.11.4

[Qemu-devel] [PATCH 1/2] configure: Define OS_OBJECT_USE_OBJC=0 for MacOSX builds

[Peter Maydell]

MacOSX 10.8 ("Mountain Lion") defaults to trying to use automated
reference counting on certain objects.  This means that the system
header files will use some Objective C syntax constructs even when
compiling pure C, which confuses mainline gcc. Suppress this by
setting OS_OBJECT_USE_OBJC=0. This avoids a compile error like this:

In file included from
/System/Library/Frameworks/Foundation.framework/Headers/NSObject.h:5:0,
                 from /usr/include/os/object.h:74,
                 from /usr/include/dispatch/dispatch.h:48,
                 from /System/Library/Frameworks/IOKit.framework/Headers/IOKitLib.h:56,
                 from block/raw-posix.c:35:
/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:409:1: error: stray ‘@’ in program
[with a large number of further run-on errors]

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 configure | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/configure b/configure
index f0dbc03..be4a2bb 100755
--- a/configure
+++ b/configure
@@ -452,6 +452,9 @@ Darwin)
   audio_possible_drivers="coreaudio sdl fmod"
   LDFLAGS="-framework CoreFoundation -framework IOKit $LDFLAGS"
   libs_softmmu="-F/System/Library/Frameworks -framework Cocoa -framework IOKit $libs_softmmu"
+  # 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_CFLAGS="-DOS_OBJECT_USE_OBJC=0 $QEMU_CFLAGS"
 ;;
 SunOS)
   solaris="yes"
-- 
1.7.11.4

[Qemu-devel] [PATCH 2/2] Support using a different compiler for Objective-C files

[Peter Maydell]

MacOSX 10.8 ("Mountain Lion") requires us to compile our one
Objective-C source file with clang even if the rest of QEMU
requires a real gcc, because the system headers we use make
use of Apple's "Blocks" extension to C/ObjC, and mainline
gcc doesn't support that. Since we only need to use a true
gcc for the parts of QEMU that use the fixed-register
env variable, we can simply use clang to build the ObjC
file: it will link to the gcc-built objects with no problems.

Add the necessary support for an OBJCC variable in the
makefile and configure machinery; we default to clang
if we have it, otherwise whatever CC is (since gcc
might be the Apple gcc which does support Blocks).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 configure | 12 ++++++++++++
 rules.mak |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/configure b/configure
index be4a2bb..bd62d2c 100755
--- a/configure
+++ b/configure
@@ -534,6 +534,13 @@ fi
 : ${python=${PYTHON-python}}
 : ${smbd=${SMBD-/usr/sbin/smbd}}
 
+# Default objcc to clang if available, otherwise use CC
+if has clang; then
+  objcc=clang
+else
+  objcc="$cc"
+fi
+
 if test "$mingw32" = "yes" ; then
   EXESUF=".exe"
   QEMU_CFLAGS="-DWIN32_LEAN_AND_MEAN -DWINVER=0x501 $QEMU_CFLAGS"
@@ -577,6 +584,8 @@ for opt do
   ;;
   --host-cc=*) host_cc="$optarg"
   ;;
+  --objcc=*) objcc="$optarg"
+  ;;
   --make=*) make="$optarg"
   ;;
   --install=*) install="$optarg"
@@ -1024,6 +1033,7 @@ echo "  --cross-prefix=PREFIX    use PREFIX for compile tools [$cross_prefix]"
 echo "  --cc=CC                  use C compiler CC [$cc]"
 echo "  --host-cc=CC             use C compiler CC [$host_cc] for code run at"
 echo "                           build time"
+echo "  --objcc=OBJCC            use Objective-C compiler OBJCC [$objcc]"
 echo "  --extra-cflags=CFLAGS    append extra C compiler flags QEMU_CFLAGS"
 echo "  --extra-ldflags=LDFLAGS  append extra linker flags LDFLAGS"
 echo "  --make=MAKE              use specified make [$make]"
@@ -3054,6 +3064,7 @@ fi
 echo "Source path       $source_path"
 echo "C compiler        $cc"
 echo "Host C compiler   $host_cc"
+echo "Objective-C compiler $objcc"
 echo "CFLAGS            $CFLAGS"
 echo "QEMU_CFLAGS       $QEMU_CFLAGS"
 echo "LDFLAGS           $LDFLAGS"
@@ -3521,6 +3532,7 @@ echo "PYTHON=$python" >> $config_host_mak
 echo "CC=$cc" >> $config_host_mak
 echo "CC_I386=$cc_i386" >> $config_host_mak
 echo "HOST_CC=$host_cc" >> $config_host_mak
+echo "OBJCC=$objcc" >> $config_host_mak
 echo "AR=$ar" >> $config_host_mak
 echo "OBJCOPY=$objcopy" >> $config_host_mak
 echo "LD=$ld" >> $config_host_mak
diff --git a/rules.mak b/rules.mak
index a284946..1b173aa 100644
--- a/rules.mak
+++ b/rules.mak
@@ -29,7 +29,7 @@ endif
 	$(call quiet-command,$(CC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  AS    $(TARGET_DIR)$@")
 
 %.o: %.m
-	$(call quiet-command,$(CC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  OBJC  $(TARGET_DIR)$@")
+	$(call quiet-command,$(OBJCC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  OBJC  $(TARGET_DIR)$@")
 
 LINK = $(call quiet-command,$(CC) $(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(sort $(1)) $(LIBS),"  LINK  $(TARGET_DIR)$@")
 
-- 
1.7.11.4

Re: [Qemu-devel] [PATCH 2/2] Support using a different compiler for Objective-C files

[Andreas Färber]

Am 11.08.2012 23:34, schrieb Peter Maydell:
> MacOSX 10.8 ("Mountain Lion") requires us to compile our one
> Objective-C source file with clang even if the rest of QEMU
> requires a real gcc, because the system headers we use make
> use of Apple's "Blocks" extension to C/ObjC, and mainline
> gcc doesn't support that. Since we only need to use a true
> gcc for the parts of QEMU that use the fixed-register
> env variable, we can simply use clang to build the ObjC
> file: it will link to the gcc-built objects with no problems.
> 
> Add the necessary support for an OBJCC variable in the
> makefile and configure machinery; we default to clang
> if we have it, otherwise whatever CC is (since gcc
> might be the Apple gcc which does support Blocks).
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  configure | 12 ++++++++++++
>  rules.mak |  2 +-
>  2 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/configure b/configure
> index be4a2bb..bd62d2c 100755
> --- a/configure
> +++ b/configure
> @@ -534,6 +534,13 @@ fi
>  : ${python=${PYTHON-python}}
>  : ${smbd=${SMBD-/usr/sbin/smbd}}
>  
> +# Default objcc to clang if available, otherwise use CC
> +if has clang; then
> +  objcc=clang

On IRC I had commented that I find defaulting to clang whenever clang is
available too aggressive (it may be some /usr/local/bin version that
doesn't even have the right host architecture support compiled in).
I won't object to this patch but would appreciate a follow-up limiting
this to v10.8+ where it's actually needed and keep using gcc elsewhere.

Andreas

> +else
> +  objcc="$cc"
> +fi
> +
>  if test "$mingw32" = "yes" ; then
>    EXESUF=".exe"
>    QEMU_CFLAGS="-DWIN32_LEAN_AND_MEAN -DWINVER=0x501 $QEMU_CFLAGS"
> @@ -577,6 +584,8 @@ for opt do
>    ;;
>    --host-cc=*) host_cc="$optarg"
>    ;;
> +  --objcc=*) objcc="$optarg"
> +  ;;
>    --make=*) make="$optarg"
>    ;;
>    --install=*) install="$optarg"
> @@ -1024,6 +1033,7 @@ echo "  --cross-prefix=PREFIX    use PREFIX for compile tools [$cross_prefix]"
>  echo "  --cc=CC                  use C compiler CC [$cc]"
>  echo "  --host-cc=CC             use C compiler CC [$host_cc] for code run at"
>  echo "                           build time"
> +echo "  --objcc=OBJCC            use Objective-C compiler OBJCC [$objcc]"
>  echo "  --extra-cflags=CFLAGS    append extra C compiler flags QEMU_CFLAGS"
>  echo "  --extra-ldflags=LDFLAGS  append extra linker flags LDFLAGS"
>  echo "  --make=MAKE              use specified make [$make]"
> @@ -3054,6 +3064,7 @@ fi
>  echo "Source path       $source_path"
>  echo "C compiler        $cc"
>  echo "Host C compiler   $host_cc"
> +echo "Objective-C compiler $objcc"
>  echo "CFLAGS            $CFLAGS"
>  echo "QEMU_CFLAGS       $QEMU_CFLAGS"
>  echo "LDFLAGS           $LDFLAGS"
> @@ -3521,6 +3532,7 @@ echo "PYTHON=$python" >> $config_host_mak
>  echo "CC=$cc" >> $config_host_mak
>  echo "CC_I386=$cc_i386" >> $config_host_mak
>  echo "HOST_CC=$host_cc" >> $config_host_mak
> +echo "OBJCC=$objcc" >> $config_host_mak
>  echo "AR=$ar" >> $config_host_mak
>  echo "OBJCOPY=$objcopy" >> $config_host_mak
>  echo "LD=$ld" >> $config_host_mak
> diff --git a/rules.mak b/rules.mak
> index a284946..1b173aa 100644
> --- a/rules.mak
> +++ b/rules.mak
> @@ -29,7 +29,7 @@ endif
>  	$(call quiet-command,$(CC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  AS    $(TARGET_DIR)$@")
>  
>  %.o: %.m
> -	$(call quiet-command,$(CC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  OBJC  $(TARGET_DIR)$@")
> +	$(call quiet-command,$(OBJCC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  OBJC  $(TARGET_DIR)$@")
>  
>  LINK = $(call quiet-command,$(CC) $(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ $(sort $(1)) $(LIBS),"  LINK  $(TARGET_DIR)$@")
>  
> 


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] [PATCH 2/2] Support using a different compiler for Objective-C files

[Peter Maydell]

On 15 August 2012 15:47, Andreas Färber <afaerber@suse.de> wrote:
> Am 11.08.2012 23:34, schrieb Peter Maydell:
>> +# Default objcc to clang if available, otherwise use CC
>> +if has clang; then
>> +  objcc=clang
>
> On IRC I had commented that I find defaulting to clang whenever clang is
> available too aggressive (it may be some /usr/local/bin version that
> doesn't even have the right host architecture support compiled in).
> I won't object to this patch but would appreciate a follow-up limiting
> this to v10.8+ where it's actually needed and keep using gcc elsewhere.

Mmm. It might be better to explicitly test for a compiler
with Blocks support (although even then you might end up
with clang on pre-10.8; I don't really want to check for "does
header Foo need blocks support" because that seems a bit fragile.)

-- PMM

Re: [Qemu-devel] [PATCH 2/2] Support using a different compiler for Objective-C files

[Andreas Färber]

Am 15.08.2012 16:55, schrieb Peter Maydell:
> On 15 August 2012 15:47, Andreas Färber <afaerber@suse.de> wrote:
>> Am 11.08.2012 23:34, schrieb Peter Maydell:
>>> +# Default objcc to clang if available, otherwise use CC
>>> +if has clang; then
>>> +  objcc=clang
>>
>> On IRC I had commented that I find defaulting to clang whenever clang is
>> available too aggressive (it may be some /usr/local/bin version that
>> doesn't even have the right host architecture support compiled in).
>> I won't object to this patch but would appreciate a follow-up limiting
>> this to v10.8+ where it's actually needed and keep using gcc elsewhere.
> 
> Mmm. It might be better to explicitly test for a compiler
> with Blocks support (although even then you might end up
> with clang on pre-10.8; I don't really want to check for "does
> header Foo need blocks support" because that seems a bit fragile.)

A simple does-clang-compile-a-hello-word-for-host check, falling back to
gcc, should catch the worst regressions as well.

Andreas

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg