Question

My project is in XCode 4.2. This project compiles for a regular debug build.

But when I change the build type to profile (I want to profile memory usage), I get the error from this objective-c++ c++ class:

/Volumes/mchinen/scm/Voicer/FilterAudioMixer.mm:53: error: stray ‘@’
in program /Volumes/mchinen/scm/Voicer/FilterAudioMixer.mm: In member
function ‘void FilterAudioMixer::WriteToBuffer(SInt16*, int)’:
/Volumes/mchinen/scm/Voicer/FilterAudioMixer.mm:53: error:
‘autoreleasepool’ was not declared in this scope
/Volumes/mchinen/scm/Voicer/FilterAudioMixer.mm:53: error: expected
;' before '{' token
/Volumes/mchinen/scm/Voicer/FilterAudioMixer.mm:147: error: expected
}’ at end of input

the @autoreleasepool line below is line 53:

void FilterAudioMixer::WriteToBuffer(SInt16* buffer, int nb_samps)
{
   @autoreleasepool {
      //do a per element lock (todo)
      pthread_mutex_lock(&playlist_lock);
      FilterSound *snd;

      size_t count = playlist.size();
      for (size_t i = 0; i < count; i++) {
         snd = playlist[i];
         [snd writeToBuffer:buffer samples:nb_samps];
      }
      pthread_mutex_unlock(&playlist_lock);

      if (m_mute) {
         memset(buffer, 0, sizeof(SInt16) * 2 * nb_samps);
      }
   }
}

It would appear that @autoreleasepool is giving me problems only under profile, why is that?

For completeness, here is the compile line from the build result window:

CompileC
/Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Intermediates/Voicer.build/Release-iphoneos/Voicer.build/Objects-normal/armv7/FilterAudioMixer.o
FilterAudioMixer.mm normal armv7 objective-c++
com.apple.compilers.llvmgcc42
cd /Volumes/mchinen/scm/Voicer
setenv LANG en_US.US-ASCII
setenv PATH “/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin”
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/llvm-gcc-4.2
-x objective-c++ -arch armv7 -fmessage-length=0 -pipe -Wno-trigraphs -fpascal-strings -Os -Wreturn-type -Wunused-variable -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk
-gdwarf-2 -fvisibility=hidden -fvisibility-inlines-hidden -mthumb -miphoneos-version-min=4.0 -iquote /Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Intermediates/Voicer.build/Release-iphoneos/Voicer.build/Voicer-generated-files.hmap
-I/Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Intermediates/Voicer.build/Release-iphoneos/Voicer.build/Voicer-own-target-headers.hmap
-I/Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Intermediates/Voicer.build/Release-iphoneos/Voicer.build/Voicer-all-target-headers.hmap
-iquote /Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Intermediates/Voicer.build/Release-iphoneos/Voicer.build/Voicer-project-headers.hmap
-iquote. -iquotePictures -iquoteCocoaSoundCloudUI -iquoteCocoaSoundCloudAPI -iquoteOHAttributedLabel -iquoteOAuth2Client -iquoteVoicer.xcworkspace -iquoteClasses -iquotehelp -iquoteJSONKit -iquoteShaders -iquoteaudio -iquotePictures/extremeprogrammingpics -iquotePictures/2010 -iquotePictures/Webcam -iquotePictures/2011 -iquotePictures/gui -iquoteCocoaSoundCloudUI/SoundCloud.bundle -iquoteCocoaSoundCloudUI/Sources -iquoteCocoaSoundCloudAPI/Sources “-iquoteOHAttributedLabel/AttributedLabel Example”
-iquoteOHAttributedLabel/OHAttributedLabel -iquoteOAuth2Client/Sources -iquoteVoicer.xcworkspace/xcuserdata -iquoteJSONKit/JSONKit -iquoteaudio/CAExtras -iquotePictures/2010/06 -iquotePictures/2010/07 -iquotePictures/2010/08 -iquotePictures/2011/12 -iquotePictures/2011/10 -iquotePictures/2011/11 -iquotePictures/2011/09 -iquotePictures/2011/07 -iquotePictures/2011/08 -iquotePictures/gui/rec -iquotePictures/gui/buttonentity -iquoteCocoaSoundCloudUI/Sources/CocoaAdditions -iquoteCocoaSoundCloudUI/Sources/SoundCloudUI -iquoteCocoaSoundCloudAPI/Sources/SoundCloudAPI “-iquoteOHAttributedLabel/AttributedLabel Example/Classes”
-iquoteOAuth2Client/Sources/OAuth2Client -iquoteVoicer.xcworkspace/xcuserdata/mchinen.xcuserdatad -iquotePictures/2010/06/25 -iquotePictures/2010/07/22 -iquotePictures/2010/07/18 -iquotePictures/2010/08/25 -iquotePictures/2010/08/29 -iquotePictures/2010/08/07 -iquotePictures/2010/08/03 -iquotePictures/2011/12/16 -iquotePictures/2011/12/14 -iquotePictures/2011/12/17 -iquotePictures/2011/12/15 -iquotePictures/2011/10/26 -iquotePictures/2011/10/30 -iquotePictures/2011/10/21 -iquotePictures/2011/10/22 -iquotePictures/2011/10/13 -iquotePictures/2011/11/18 -iquotePictures/2011/11/19 -iquotePictures/2011/09/26 -iquotePictures/2011/09/25 -iquotePictures/2011/09/01 -iquotePictures/2011/09/21 -iquotePictures/2011/09/07 -iquotePictures/2011/09/13 -iquotePictures/2011/09/19 -iquotePictures/2011/07/17 -iquotePictures/2011/08/30 -iquotePictures/2011/08/23 -iquotePictures/2011/08/29 -iquoteVoicer.xcworkspace/xcuserdata/mchinen.xcuserdatad/xcdebugger -I/Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Products/Release-iphoneos/include
-I/Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Intermediates/Voicer.build/Release-iphoneos/Voicer.build/DerivedSources/armv7
-I/Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Intermediates/Voicer.build/Release-iphoneos/Voicer.build/DerivedSources
-F/Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Products/Release-iphoneos
-DNS_BLOCK_ASSERTIONS=1 -include /Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Intermediates/PrecompiledHeaders/Filter_Prefix-hbhtwvzcunnlquaijtkwxcnrmocg/Filter_Prefix.pch
-c /Volumes/mchinen/scm/Voicer/FilterAudioMixer.mm -o /Users/mchinen/Library/Developer/Xcode/DerivedData/Voicer-aebonlzraugcbqarecvubzkhxlfr/Build/Intermediates/Voicer.build/Release-iphoneos/Voicer.build/Objects-normal/armv7/FilterAudioMixer.o

Answer 1

The important part of that build log is:

gcc-4.2

Something in your build settings is causing you to use the old GCC 4.2 compiler, which doesn’t support @autoreleasepool. (More explanation in this answer.)

In your scheme, check what build configuration “Profile” is using. Then, check the settings in your project and target for that build configuration.