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iosxcodeclanglinker-errorsduplicate-symbol

Compiler returns clang error 1 without apparent reason


I do not see where there is a circular definition or two files that have the same name, can someone please tell me how to read and understand this linker error message?

Ld /Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Products/Debug-iphonesimulator/myMilesApp.app/myMilesApp normal x86_64
cd /Users/jurgendictus/Dropbox/proggies/xCode/myMilesApp/myMilesApp
export IPHONEOS_DEPLOYMENT_TARGET=9.3
export PATH="/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.3.sdk -L/Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Products/Debug-iphonesimulator -F/Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Products/Debug-iphonesimulator -filelist /Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Intermediates/myMilesApp.build/Debug-iphonesimulator/myMilesApp.build/Objects-normal/x86_64/myMilesApp.LinkFileList -Xlinker -rpath -Xlinker @executable_path/Frameworks -mios-simulator-version-min=9.3 -Xlinker -no_deduplicate -Xlinker -objc_abi_version -Xlinker 2 -fobjc-arc -fobjc-link-runtime -L/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphonesimulator -Xlinker -add_ast_path -Xlinker /Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Intermediates/myMilesApp.build/Debug-iphonesimulator/myMilesApp.build/Objects-normal/x86_64/myMilesApp.swiftmodule -lsqlite3.0 -framework UIKit -Xlinker -dependency_info -Xlinker /Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Intermediates/myMilesApp.build/Debug-iphonesimulator/myMilesApp.build/Objects-normal/x86_64/myMilesApp_dependency_info.dat -o /Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Products/Debug-iphonesimulator/myMilesApp.app/myMilesApp

duplicate symbol _logMethods in:
/Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Intermediates/myMilesApp.build/Debug-iphonesimulator/myMilesApp.build/Objects-normal/x86_64/beDbAccess.o
/Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Intermediates/myMilesApp.build/Debug-iphonesimulator/myMilesApp.build/Objects-normal/x86_64/beGlobalFunctions.o
duplicate symbol _logEndMethods in:
/Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Intermediates/myMilesApp.build/Debug-iphonesimulator/myMilesApp.build/Objects-normal/x86_64/beDbAccess.o
/Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Intermediates/myMilesApp.build/Debug-iphonesimulator/myMilesApp.build/Objects-normal/x86_64/beGlobalFunctions.o
duplicate symbol _verbose in:
/Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Intermediates/myMilesApp.build/Debug-iphonesimulator/myMilesApp.build/Objects-normal/x86_64/beDbAccess.o
/Users/jurgendictus/Library/Developer/Xcode/DerivedData/myMilesApp-fytkctapxamadqdmxvtpdexztqjr/Build/Intermediates/myMilesApp.build/Debug-iphonesimulator/myMilesApp.build/Objects-normal/x86_64/beGlobalFunctions.o
ld: 3 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I guess it must be somewhere in the beGlobalFunctions.h or the beDbAccess.h


Solution

  • Ok, It seems that I overlooked the variable names logMethods, logEndMethods and verbose in the error log. I moved the declaration into the .m files under the implementation.

    ex.

    @implementation beDbAccess
    {
        BOOL logMethods, logEndMethods, verbose;
    }
    

    and this solved the compiling error