ios - -Objc 其他链接器标志给出重复符号错误

Question

我正在使用 Unrar4iOS.Framework。它工作正常但是当我添加 -Objc 其他链接器标志时。它给了我重复的错误。

    duplicate symbol __Z12CallbackProcjlll in:
    Library/Developer/Xcode/DerivedData/SARUnArchiveANY-fgljekydpkmvrlgapbahtfvvhsdl/Build/Intermediates/SARUnArchiveANY.build/Debug-iphonesimulator/SARUnArchiveANY.build/Objects-normal/x86_64/Unrar4iOS.o
    /My Project/SARUnArchiveANY-master/SARUnArchiveANY/vendor/Frameworks/Unrar4iOS.framework/Unrar4iOS(Unrar4iOS.o)
duplicate symbol _OBJC_IVAR_$_Unrar4iOS.header in:
    Library/Developer/Xcode/DerivedData/SARUnArchiveANY-fgljekydpkmvrlgapbahtfvvhsdl/Build/Intermediates/SARUnArchiveANY.build/Debug-iphonesimulator/SARUnArchiveANY.build/Objects-normal/x86_64/Unrar4iOS.o
    My Project/SARUnArchiveANY-master/SARUnArchiveANY/vendor/Frameworks/Unrar4iOS.framework/Unrar4iOS(Unrar4iOS.o)
duplicate symbol _OBJC_IVAR_$_Unrar4iOS.flags in:
    Library/Developer/Xcode/DerivedData/SARUnArchiveANY-fgljekydpkmvrlgapbahtfvvhsdl/Build/Intermediates/SARUnArchiveANY.build/Debug-iphonesimulator/SARUnArchiveANY.build/Objects-normal/x86_64/Unrar4iOS.o
    My Project/SARUnArchiveANY-master/SARUnArchiveANY/vendor/Frameworks/Unrar4iOS.framework/Unrar4iOS(Unrar4iOS.o)

我需要添加使用 Objc 标志才能使用其他库。

Answer 1

如果您指定 -all_load 或 -Objc 标志，并且静态库在您的项目中具有与类相同的符号名称，
您将在链接时看到这些“重复符号”错误。

为什么？

This flag causes the linker to load every object file in the library that defines an Objective-C class or category. While this option will typically result in a larger executable (due to additional object code loaded into the application), it will allow the successful creation of effective Objective-C static libraries that contain categories on existing classes.

from Apple official document.

在您的项目中，现在，Unrar4iOS.o 中的 3 个符号已崩溃。

例如，在您的第一个重复符号错误日志中，

__Z12CallbackProcjlll 符号在
中崩溃(1) 库/Developer/Xcode/DerivedData/SARUnArchiveANY-fgljekydpkmvrlgapbahtfvvhsdl/Build/Intermediates/SARUnArchiveANY.build/Debug-iphonesimulator/SARUnArchiveANY.build/Objects-normal/x86_64/Unrar4iOS.o

(2)/我的项目/SARUnArchiveANY-master/SARUnArchiveANY/vendor/Frameworks/Unrar4iOS.framework/Unrar4iOS(Unrar4iOS.o)

第二个和第三个重复符号将使用相同的模式。

duplicate symbol __Z12CallbackProcjlll in:
Library/Developer/Xcode/DerivedData/SARUnArchiveANY-fgljekydpkmvrlgapbahtfvvhsdl/Build/Intermediates/SARUnArchiveANY.build/Debug-iphonesimulator/SARUnArchiveANY.build/Objects-normal/x86_64/Unrar4iOS.o
/My Project/SARUnArchiveANY-master/SARUnArchiveANY/vendor/Frameworks/Unrar4iOS.framework/Unrar4iOS(Unrar4iOS.o)

duplicate symbol _OBJC_IVAR_$_Unrar4iOS.header in:
Library/Developer/Xcode/DerivedData/SARUnArchiveANY-fgljekydpkmvrlgapbahtfvvhsdl/Build/Intermediates/SARUnArchiveANY.build/Debug-iphonesimulator/SARUnArchiveANY.build/Objects-normal/x86_64/Unrar4iOS.o
My Project/SARUnArchiveANY-master/SARUnArchiveANY/vendor/Frameworks/Unrar4iOS.framework/Unrar4iOS(Unrar4iOS.o)

duplicate symbol _OBJC_IVAR_$_Unrar4iOS.flags in:
Library/Developer/Xcode/DerivedData/SARUnArchiveANY-fgljekydpkmvrlgapbahtfvvhsdl/Build/Intermediates/SARUnArchiveANY.build/Debug-iphonesimulator/SARUnArchiveANY.build/Objects-normal/x86_64/Unrar4iOS.o
My Project/SARUnArchiveANY-master/SARUnArchiveANY/vendor/Frameworks/Unrar4iOS.framework/Unrar4iOS(Unrar4iOS.o)

因此，为了总结您的项目症状，现在，在您的项目中，
Unrar4iOS.framework 和 SARUnArchiveANY 库在 Unrar4iOS 目标文件中出现三个重复的符号而相互崩溃。

另外，下面是SARUnArchiveANY git仓库介绍。
它已经指定 SARUnArchiveANY 库包含 Unrar4iOS。

SARUnArchiveANY

A very useful library for Unarchiving the .zip, .rar, .7z files for iOS. Simply An Integration of the following libraries :

Unrar4iOS
SSZipArchive
LZMA SDK (7z)

from https://github.com/saru2020/SARUnArchiveANY

为了解决这个问题，我推荐这个链接。
http://atnan.com/blog/2012/01/12/avoiding-duplicate-symbol-errors-during-linking-by-removing-classes-from-static-libraries

你可以解决这个问题，因为我已经这样做过了。