title: Apple LLVM compiler 3.1 error
body: <p>Just updated Xcode to 4.3 and now I can't build my app.  I'm getting this error: </p>
  
  <pre><code>Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang failed with exit code 254
  </code></pre>
  
  <p>Anybody else having this problem?  It's probably just a compilation setting but I'm not sure where to look.</p>
  
  <p>Of course, the error includes the entire stack dump, but I've not included that for sake of brevity.  I'm hoping that someone will know what "exit code 254" is.  Tried searching for it but couldn't find anything.</p>
  
  <p>Here's the entire output:</p>
  
  <pre><code>CompileC /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Objects-normal/i386/SCheckBox.o iDB/SCheckBox.m normal i386 objective-c com.apple.compilers.llvm.clang.1_0.compiler
      cd "/Users/aaron/Dropbox/XCode Projects/iDB"
      setenv LANG en_US.US-ASCII
      setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
      /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -x objective-c -arch i386 -fmessage-length=0 -std=gnu99 -fobjc-arc -Wno-trigraphs -fpascal-strings -O0 -Werror -Wno-missing-field-initializers -Wmissing-prototypes -Wreturn-type -Wno-implicit-atomic-properties -Wformat -Wno-missing-braces -Wparentheses -Wswitch -Wunused-function -Wunused-label -Wno-unused-parameter -Wunused-variable -Wunused-value -Wno-uninitialized -Wno-unknown-pragmas -Wno-shadow -Wno-four-char-constants -Wno-sign-compare -Wno-shorten-64-to-32 -Wpointer-sign -Wno-newline-eof -Wno-selector -Wno-strict-selector-match -Wno-undeclared-selector -Wno-deprecated-implementations -DDEBUG=1 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk -fexceptions -fasm-blocks -Wprotocol -Wdeprecated-declarations -mmacosx-version-min=10.6 -g -Wno-conversion -Wno-sign-conversion -fobjc-abi-version=2 -fobjc-legacy-dispatch "-DIBOutlet=__attribute__((iboutlet))" "-DIBOutletCollection(ClassName)=__attribute__((iboutletcollection(ClassName)))" "-DIBAction=void)__attribute__((ibaction)" -D__IPHONE_OS_VERSION_MIN_REQUIRED=50000 -iquote /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Flexile-generated-files.hmap -I/Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Flexile-own-target-headers.hmap -I/Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Flexile-all-target-headers.hmap -iquote /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Flexile-project-headers.hmap -I/Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Products/Debug-iphonesimulator/include -I/Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/DerivedSources/i386 -I/Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/DerivedSources -F/Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Products/Debug-iphonesimulator -include /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/PrecompiledHeaders/iDB-Prefix-aojkwzmrifipbudgsdryqwbhphsf/iDB-Prefix.pch -MMD -MT dependencies -MF /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Objects-normal/i386/SCheckBox.d --serialize-diagnostics /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Objects-normal/i386/SCheckBox.dia -c "/Users/aaron/Dropbox/XCode Projects/iDB/iDB/SCheckBox.m" -o /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Objects-normal/i386/SCheckBox.o
  
  0  clang             0x000000010a5c15a2 _ZL15PrintStackTracePv + 34
  1  clang             0x000000010a5c1a29 _ZL13SignalHandleri + 553
  2  libsystem_c.dylib 0x00007fff94b6dcfa _sigtramp + 26
  3  libsystem_c.dylib 0x00007fff6929a1b0 _sigtramp + 18446744072978875600
  4  clang             0x0000000109ef3798 _ZL20findRetainCycleOwnerPN5clang4ExprERN12_GLOBAL__N_116RetainCycleOwnerE + 312
  5  clang             0x0000000109ef35af clang::Sema::checkRetainCycles(clang::ObjCMessageExpr*) + 303
  6  clang             0x00000001097efaef clang::Sema::BuildInstanceMessage(clang::Expr*, clang::QualType, clang::SourceLocation, clang::Selector, clang::ObjCMethodDecl*, clang::SourceLocation, llvm::ArrayRef&lt;clang::SourceLocation&gt;, clang::SourceLocation, clang::ASTMultiPtr&lt;clang::Expr*&gt;) + 6479
  7  clang             0x00000001097ee18a clang::Sema::ActOnInstanceMessage(clang::Scope*, clang::Expr*, clang::Selector, clang::SourceLocation, llvm::ArrayRef&lt;clang::SourceLocation&gt;, clang::SourceLocation, clang::ASTMultiPtr&lt;clang::Expr*&gt;) + 138
  8  clang             0x00000001097ee04b clang::Parser::ParseObjCMessageExpressionBody(clang::SourceLocation, clang::SourceLocation, clang::OpaquePtr&lt;clang::QualType&gt;, clang::Expr*) + 2091
  9  clang             0x00000001097ed7f4 clang::Parser::ParseObjCMessageExpression() + 852
  10 clang             0x0000000109765597 clang::Parser::ParseCastExpression(bool, bool, bool&amp;, bool) + 6807
  11 clang             0x0000000109763ab2 clang::Parser::ParseAssignmentExpression() + 114
  12 clang             0x0000000109763a21 clang::Parser::ParseExpression() + 17
  13 clang             0x00000001097b8efe clang::Parser::ParseExprStatement(clang::ParsedAttributes&amp;) + 46
  14 clang             0x00000001097634bc clang::Parser::ParseStatementOrDeclaration(clang::ASTOwningVector&lt;clang::Stmt*, 32u&gt;&amp;, bool) + 1564
  15 clang             0x00000001097627d9 clang::Parser::ParseCompoundStatementBody(bool) + 409
  16 clang             0x0000000109763242 clang::Parser::ParseStatementOrDeclaration(clang::ASTOwningVector&lt;clang::Stmt*, 32u&gt;&amp;, bool) + 930
  17 clang             0x00000001097b6d0b clang::Parser::ParseIfStatement(clang::ParsedAttributes&amp;) + 475
  18 clang             0x000000010976353c clang::Parser::ParseStatementOrDeclaration(clang::ASTOwningVector&lt;clang::Stmt*, 32u&gt;&amp;, bool) + 1692
  19 clang             0x00000001097627d9 clang::Parser::ParseCompoundStatementBody(bool) + 409
  20 clang             0x0000000109edbd30 clang::Parser::ParseLexedObjCMethodDefs(clang::Parser::LexedMethod&amp;) + 272
  21 clang             0x000000010980483e clang::Parser::ParseObjCAtEndDeclaration(clang::SourceRange) + 158
  22 clang             0x00000001097e2222 clang::Parser::ParseObjCAtDirectives() + 386
  23 clang             0x0000000109723e87 clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&amp;, clang::Parser::ParsingDeclSpec*) + 759
  24 clang             0x0000000109723b19 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr&lt;clang::DeclGroupRef&gt;&amp;) + 249
  25 clang             0x000000010970688b clang::ParseAST(clang::Sema&amp;, bool) + 299
  26 clang             0x00000001097053d9 clang::CodeGenAction::ExecuteAction() + 857
  27 clang             0x00000001096d793f clang::CompilerInstance::ExecuteAction(clang::FrontendAction&amp;) + 879
  28 clang             0x00000001096d65cb clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 2683
  29 clang             0x00000001096c8dce cc1_main(char const**, char const**, char const*, void*) + 5086
  30 clang             0x00000001096a35d8 main + 648
  31 clang             0x00000001096a3344 start + 52
  32 clang             0x0000000000000071 start + 18446744069256629601
  Stack dump:
  0.  Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -cc1 -triple i386-apple-macosx10.6.0 -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -main-file-name SCheckBox.m -pic-level 1 -mdisable-fp-elim -relaxed-aliasing -masm-verbose -target-cpu yonah -target-linker-version 128.2 -g -coverage-file /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Objects-normal/i386/SCheckBox.o -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/3.1 -dependency-file /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Objects-normal/i386/SCheckBox.d -MT dependencies -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk -iquote /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Flexile-generated-files.hmap -iquote /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Flexile-project-headers.hmap -include-pch /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/PrecompiledHeaders/iDB-Prefix-aojkwzmrifipbudgsdryqwbhphsf/iDB-Prefix.pch.pth -D DEBUG=1 -D IBOutlet=__attribute__((iboutlet)) -D IBOutletCollection(ClassName)=__attribute__((iboutletcollection(ClassName))) -D IBAction=void)__attribute__((ibaction) -D __IPHONE_OS_VERSION_MIN_REQUIRED=50000 -I /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Flexile-own-target-headers.hmap -I /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Flexile-all-target-headers.hmap -I /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Products/Debug-iphonesimulator/include -I /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/DerivedSources/i386 -I /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/DerivedSources -F/Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Products/Debug-iphonesimulator -fmodule-cache-path /var/folders/1y/fbhzgfpn2ld9qxdfpgl7d_rm0000gn/T/clang-module-cache -O0 -Wno-trigraphs -Werror -Wno-missing-field-initializers -Wmissing-prototypes -Wreturn-type -Wno-implicit-atomic-properties -Wformat -Wno-missing-braces -Wparentheses -Wswitch -Wunused-function -Wunused-label -Wno-unused-parameter -Wunused-variable -Wunused-value -Wno-uninitialized -Wno-unknown-pragmas -Wno-shadow -Wno-four-char-constants -Wno-sign-compare -Wno-shorten-64-to-32 -Wpointer-sign -Wno-newline-eof -Wno-selector -Wno-strict-selector-match -Wno-undeclared-selector -Wno-deprecated-implementations -Wprotocol -Wdeprecated-declarations -Wno-conversion -Wno-sign-conversion -std=gnu99 -ferror-limit 19 -fmessage-length 0 -stack-protector 1 -fblocks -fobjc-runtime-has-arc -fobjc-runtime-has-weak -fobjc-arc -fobjc-exceptions -fexceptions -fpascal-strings -fdiagnostics-show-option -serialize-diagnostic-file /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Objects-normal/i386/SCheckBox.dia -o /Users/aaron/Library/Developer/Xcode/DerivedData/iDB-cvvkmobzsecywdherzjesrjswdng/Build/Intermediates/iDB.build/Debug-iphonesimulator/Flexile.build/Objects-normal/i386/SCheckBox.o -x objective-c /Users/aaron/Dropbox/XCode Projects/iDB/iDB/SCheckBox.m 
  1.  /Users/aaron/Dropbox/XCode Projects/iDB/iDB/SCheckBox.m:36:47: current parser token ';'
  2.  /Users/aaron/Dropbox/XCode Projects/iDB/iDB/SCheckBox.m:27:146: in compound statement ('{}')
  3.  /Users/aaron/Dropbox/XCode Projects/iDB/iDB/SCheckBox.m:29:102: in compound statement ('{}')
  clang: error: unable to execute command: Segmentation fault: 11
  clang: error: clang frontend command failed due to signal 2 (use -v to see invocation)
  clang: note: diagnostic msg: Please submit a bug report to http://developer.apple.com/bugreporter/ and include command line arguments and all diagnostic information.
  clang: note: diagnostic msg: Preprocessed source(s) and associated run script(s) are located at:
  clang: note: diagnostic msg: /var/folders/1y/fbhzgfpn2ld9qxdfpgl7d_rm0000gn/T/SCheckBox-GckJrn.mi
  clang: note: diagnostic msg: /var/folders/1y/fbhzgfpn2ld9qxdfpgl7d_rm0000gn/T/SCheckBox-GckJrn.sh
  Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang failed with exit code 254
  </code></pre>
  
  <p><strong>UPDATE</strong>
  So I noticed that the dump refers to specific lines on code in a specific class (SCheckBox.m).
  It's in an init method.  I've checked over the method but could not find anything wrong with it.  However, if I comment everything inside the method out and return nil, the code compiles.  I went through and uncommented every line until I got the error.  The error causing the problem is this: </p>
  
  <pre><code>[super.inputField addSubview:_checked];
  </code></pre>
  
  <p>I had intended on using 'self' instead of 'super'(which was a typo on my part).  But super does in fact have a inputField property.  It's not redefined or overwritten in the subclass.  So accessing 'super.inputField' vs 'self.inputField' should access the exact same thing (and did before upgrading Xcode).  OK, so changing 'super' to 'self' does fix the problem.</p>
  
  <p>My question now is: Why?</p>