链接错误

Question

更新：

我才意识到，你可以通过设置LD_TRACE_ARCHIVES和LD_TRACE_DYLIBS环境变量，然后直接在命令行中运行链接器命令获得更多的信息。下面是我执行，然后它的输出（虽然我更换了一些很长的路径和名称与<short-text>字符串）：

/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/g++-4.2 
-arch i386 
-isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk 
-L<path_to_project>/build/Debug-iphonesimulator 
-L<path_to_static_libs> 
-F<path_to_project>/build/Debug-iphonesimulator 
-filelist <path_to_project>/build/<project_name>.build/Debug-iphonesimulator/<project_name>.build/Objects-normal/i386/<project_name>.LinkFileList 
-mmacosx-version-min=10.6 
--verbose 
-lproject_lib 
-Xlinker -objc_abi_version 
-Xlinker 2 
-framework Foundation -framework UIKit -framework OpenGLES -framework QuartzCore 
-o <path_to_project>/build/Debug-iphonesimulator/<project_name>.app/<project_name> 

Using built-in specs. 
Target: i686-apple-darwin10 
Thread model: posix 
gcc version 4.2.1 (Apple Inc. build 5664) 
/Developer/usr/bin/../libexec/gcc/i686-apple-darwin10/4.2.1/collect2 
-dynamic -arch i386 -macosx_version_min 10.6 
-syslibroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk 
-weak_reference_mismatches non-weak 
-o <path_to_project>/build/Debug-iphonesimulator/<project_name>.app/<project_name> 
-lcrt1.10.6.o 
-L<path_to_project>/build/Debug-iphonesimulator 
-L<path_to_static_libs> 
-L/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/usr/lib 
-L/Developer/usr/bin/../lib/gcc/i686-apple-darwin10/4.2.1 
-L/Developer/usr/bin/../lib/gcc 
-L/usr/lib/gcc/i686-apple-darwin10/4.2.1 
-L/usr/lib/gcc/i686-apple-darwin10/4.2.1 
-L/Developer/usr/bin/../lib/gcc/i686-apple-darwin10/4.2.1/../../../i686-apple-darwin10/4.2.1 
-L/Developer/usr/bin/../lib/gcc/i686-apple-darwin10/4.2.1/../../.. 
-L/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../.. 
-filelist <path_to_project>/build/<project_name>.build/Debug-iphonesimulator/<project_name>.build/Objects-normal/i386/<project_name>.LinkFileList 
-lproject_lib 
-objc_abi_version 2 
-framework Foundation -framework UIKit -framework OpenGLES -framework QuartzCore 
-lstdc++ -lSystem -lgcc -lSystem 
-F<path_to_project>/build/Debug-iphonesimulator 

[Logging for XBS] Used dynamic library: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/System/Library/Frameworks/Foundation.framework/Foundation 
[Logging for XBS] Used dynamic library: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/System/Library/Frameworks/UIKit.framework/UIKit 
[Logging for XBS] Used dynamic library: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/System/Library/Frameworks/OpenGLES.framework/OpenGLES 
[Logging for XBS] Used dynamic library: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/System/Library/Frameworks/QuartzCore.framework/QuartzCore 
[Logging for XBS] Used dynamic library: /Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1/libstdc++.dylib 
[Logging for XBS] Used dynamic library: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/usr/lib/libSystem.dylib 
[Logging for XBS] Used indirect dynamic library: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/usr/lib/libobjc.A.dylib 
[Logging for XBS] Used indirect dynamic library: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation 
[Logging for XBS] Used indirect dynamic library: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/usr/lib/system/libSystem.override.dylib 
[Logging for XBS] Used indirect dynamic library: /usr/lib/libSystem.B.dylib 
[Logging for XBS] Used indirect dynamic library: /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/usr/lib/system/libmathCommon.A.dylib 
[Logging for XBS] Used static archive: <path_to_static_libs>/libproject_lib.a 

Undefined symbols: 
    ".objc_class_name_NSBundle", referenced from: 
     literal-pointer@__OBJC@__cls_refs@NSBundle in libproject_lib.a(file1.o) 
    ".objc_class_name_UIWindow", referenced from: 
     literal-pointer@__OBJC@__cls_refs@UIWindow in libproject_lib.a(file2.o) 
    ".objc_class_name_UIView", referenced from: 
     .objc_class_name_file3 in libproject_lib.a(file3.o) 
    ".objc_class_name_CAEAGLLayer", referenced from: 
     literal-pointer@__OBJC@__cls_refs@CAEAGLLayer in libproject_lib.a(file3.o) 
    ".objc_class_name_EAGLContext", referenced from: 
     literal-pointer@__OBJC@__cls_refs@EAGLContext in libproject_lib.a(file2.o) 
     literal-pointer@__OBJC@__cls_refs@EAGLContext in libproject_lib.a(file3.o) 
    ".objc_class_name_NSDictionary", referenced from: 
     literal-pointer@__OBJC@__cls_refs@NSDictionary in libproject_lib.a(file3.o) 
    ".objc_class_name_NSNumber", referenced from: 
     literal-pointer@__OBJC@__cls_refs@NSNumber in libproject_lib.a(file3.o) 
    ".objc_class_name_UIScreen", referenced from: 
     literal-pointer@__OBJC@__cls_refs@UIScreen in libproject_lib.a(file2.o) 

ld: symbol(s) not found 
collect2: ld returned 1 exit status 

所以，问题是：为什么没有被发现，即使collect2的.objc_class_name_xxx引用正在研究iPhoneSimulator的正确框架位置？这里的要点是，这一切都正常工作，当针对iPhone设备本身时，没有链接错误。

原始邮件：

我已经编译并在Xcode链接的精细标定设备本身（新iPad）时，而是一个应用程序，当我尝试目标模拟器我得到指示的错误，从我的框架符号没有找到m使用。

我已经看到了与此相关的一些旧的线程，但他们的建议不工作： 1）我没有复制的iPhoneOS SDK框架本地 2）我没有一个明确的框架搜索路径 3）但是，我确实有明确的库搜索路径，一个用于模拟器，一个用于设备。 4）我尝试制作明确的框架搜索路径，一个用于模拟器，一个用于设备，但也不起作用，尽管生成的gcc命令行具有正确的模拟器的-syslib和-F选项。

我一直坚持这一段时间了。有没有人有任何进一步的洞察可能会发生什么？我只是连接4个基础框架，Foundation，UIKit，QuartzCore和OpenGLES。

感谢，

-Eric

Answer 1

我终于想通了这一点：

的问题是在我的静态库，没有被正确地产生的外部引用，因为我不知道我需要当正在构建静态库的模块时，-fobjc-abi-version = 2命令行选项。

主要的困惑是，当瞄准设备时，这个命令行选项是不必要的（尽管我相信它在这种情况下是无害的），但是在瞄准模拟器时这是必须的。

因此，如果您要为将链接到iOS目标的模块创建makefile，请确保包含此选项！

-Eric