鏈接錯誤

Question

更新：

我才意識到，你可以通過設置LD_TRACE_ARCHIVES和LD_TRACE_DYLIBS環境變量，然後直接在命令行中運行鏈接器命令獲得更多的信息。下面是我執行，然後它的輸出（雖然我更換了一些很長的路徑和名稱與<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，問題是：爲什麼沒有被發現，即使collect2的.objc_class_name_xxx引用正在研究iPhoneSimulator的正確框架位置？這裏的要點是，這一切都正常工作，當針對iPhone設備本身時，沒有鏈接錯誤。

原始郵件：

我已經編譯並在Xcode鏈接的精細標定設備本身（新iPad）時，而是一個應用程序，當我嘗試目標模擬器我得到指示的錯誤，從我的框架符號沒有找到m使用。

我已經看到了與此相關的一些舊的線程，但他們的建議不工作： 1）我沒有複製的iPhoneOS SDK框架本地 2）我沒有一個明確的框架搜索路徑 3）但是，我確實有明確的庫搜索路徑，一個用於模擬器，一個用於設備。 4）我嘗試製作明確的框架搜索路徑，一個用於模擬器，一個用於設備，但也不起作用，儘管生成的gcc命令行具有正確的模擬器的-syslib和-F選項。

我一直堅持這一段時間了。有沒有人有任何進一步的洞察可能會發生什麼？我只是連接4個基礎框架，Foundation，UIKit，QuartzCore和OpenGLES。

感謝，

-Eric

Answer 1

我終於想通了這一點：

的問題是在我的靜態庫，沒有被正確地產生的外部引用，因爲我不知道我需要當正在構建靜態庫的模塊時，-fobjc-abi-version = 2命令行選項。

主要的困惑是，當瞄準設備時，這個命令行選項是不必要的（儘管我相信它在這種情況下是無害的），但是在瞄準模擬器時這是必須的。

因此，如果您要爲將鏈接到iOS目標的模塊創建makefile，請確保包含此選項！

-Eric