Undefined symbols for architecture armv7

Question

This problem has been driving me crazy, and I can't work out how to fix it...

    Undefined symbols for architecture armv7:
  "_deflateEnd", referenced from:
      -[ASIDataCompressor closeStream] in ASIDataCompressor.o
  "_OBJC_CLASS_$_ASIDataDecompressor", referenced from:
      objc-class-ref in ASIHTTPRequest.o
  "_deflate", referenced from:
      -[ASIDataCompressor compressBytes:length:error:shouldFinish:] in ASIDataCompressor.o
  "_deflateInit2_", referenced from:
      -[ASIDataCompressor setupStream] in ASIDataCompressor.o
ld: symbol(s) not found for architecture armv7
collect2: ld returned 1 exit status
Command /Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.2 failed with exit code 1

I think it has to do with:

ld: symbol(s) not found for architecture armv7

But I have added: libz.1.2.3.dylib and it's not helping, anyone got any ideas?

Answer 1

Common Causes

The common causes for "Undefined symbols for architecture armv7" are:

1. You import a header and do not link against the correct library. This is common, especially for headers for libraries like QuartzCore since it is not included in projects by default. To resolve:

   • Add the correct libraries in the Link Binary With Libraries section of the Build Phases.

   • If you want to add a library outside of the default search path you can include the path in the Library Search Paths value in the Build Settings and add
     -l{library_name_without_lib_and_suffix} (eg. for libz.a use -lz) to the Other Linker Flags section of Build Settings.
     
     

2. You copy files into your project but forgot to check the target to add the files to. To resolve:

   • Open the Build Phases for the correct target, expand Compile Sources and add the missing .m files. If this is your issue please upvote Cortex's answer below as well.
     
     

3. You include a static library that is built for another architecture like i386, the simulator on your host machine. To resolve:

   • If you have multiple library files from your libraries vendor to include in the project you need to include the one for the simulator (i386) and the one for the device (armv7 for example).

   • Optionally, you could create a fat static library that contains both architectures.

---

Original Answer:

You have not linked against the correct libz file. If you right click the file and reveal in finder its path should be somewhere in an iOS sdk folder. Here is mine for example

/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk/usr/lib

I recommend removing the reference and then re-adding it back in the Link Binary With Libraries section Build Phases of your target.

Answer 2

I had a similar issue last night and the problem, was related to the fact that I had dragged a class from the Finder to my project in Xcode.

The solution was to go the the Build Phases tab and then the Compile Sources and make sure you drag the class to the list.

Answer 3

I had a similar issue and I had to check "Build Active Architecture Only" on each of the Project configurations (Debug, Release and Deployment) and in the Build Settings of the Target.

Answer 4

Another possible cause of "undefined symbol" linker errors is attempting to call a C function from a .mm file. In this case you'll need to use extern "C" {...} when you import the header files.

Linker error calling C-Function from Objective-C++

Answer 5

I had a similar issue with that. The class name after _OBJC_CLASS_$_ was actually my class. The reason was I didn't tick "Add to Target" when I drag the source code files into navigation list.

My solution was:

1. delete the class from the navigation list and choose "remove reference only"

2. drag the source code files again and make sure the tick box for "add to Target" is ticked. The tick box is just under "Copy if needed" and "Create group".

Answer 6

There is usually a alias without the version identifier that is linked to the current version, in this case libz.dylib is linked to libz.1.2.5.dylib. Use the base alias instead of the versioned one.

Answer 7

I had the same problem when I use admob library, I fixed it changing "Architectures" to "Standard architectures armv7, armv7s" without including 64-bit.

Answer 8

Under Target -> Build Settings -> Apple LLVM compiler language: setting 'C++ Language Dialect' and 'C++ Standard Library' to Compiler default helped solve it.

Answer 9

I only added the libz.1.2.5.dylib to my project and it worked like a charm.

Steps -

1. Go to Build Phases.
2. Link Binary With library - use the '+' button to choose frameworks and libraries to add.
3. Select libz.1.2.5.dylib from the list.
4. Build and run.

Answer 10

I had a similar issue and saw errors related to "std::"

I changed Build Settings -> Apple LVM 5.0 - Language C++ -> C++ Standard Library

from libc++ (LLVM C++ Standard Library with C++11 support) to libstdc++ (GNU C++ Standard Library)

Answer 11

If you have the flag -ObjC under your Target > Build Settings > Other Linker Flags and you're getting this issue, consider removing it. If you intentionally added it because you need to load some Obj-C code from a static library that wouldn't normally be loaded otherwise, IE, an Obj-C category, then you should use -force_load <path> instead of -ObjC.

<path> should be relative to your Xcode project directory. IE, if your directory structure looks like this:

iOSProject
  + iOSAPI.framework
      + iOSAPI
  + iOSAPI.xcodeproj

Then you should have this flag set for Other Linker Flags:

-force_load iOSAPI.framework/iOSAPI

If you want to include multiple libraries like that, then you should include a separate -force_load line for each of them.

-force_load iOSAPI.framework/iOSAPI
-force_load another.framework/another

Answer 12

I have have multiple @interfaces in the .h file and hadn't yet included the all of the corresponding @implementation directives. Make sure that they are all balanced out.

Answer 13

Here's how I got this problem:

I added a .h, .m and NIB from another project by dragging them onto my project navigator. Xcode didn't add them to the Build Phases properly.

Check my answer because I had a similar problem that I was able to solve by doing some steps.

Answer 14

if you're dealing with the iOS5 upgrade, I found that for compiling a project written to target 4.3, I could just rename libz.1.2.3.dynlib in the Project Navigator to libz.1.2.5.dynlib and it compiled.

My iPhoneOS50SDK/usr/lib folder has no libz.1.2.3.dynlib--don't know whether it's a beta thing or just natural upgrade.

Answer 15

Go to your project, click on Build phases, Compile sources, Add GameCenterManager.m to the list.

Answer 16

Probably some classes are missing from your target. This usually happens when you rename/remove/add new classes files to your project. To fix add the newly added classes to some targets.

Select the class in the Project Navigator (right sidebar) , open the Utilities sidebar (right sidebar), from the Utilities select the File Inspector (file like icon), under the Target Membership tab tick your targets. This is all to avoid the "Remove reference" and add again with ticking "Add to targets" trick.

So: Select Class -> Utilities (File Inspector) -> Target Membership -> Tick the targets you want.

Answer 17

I didn't find this suggestion here so here it goes: if your project has more than one target (ie one for OSX and one for iOS) then you must link the relevant libraries for each target.. so for example in my case I needed AudioToolbox.. I had to add it once for OSX and once for iOS (under the frameworks folder, you must have a duplicate of each library for each target.. if you see only one.. then that's a red flag)

Answer 18

I was facing an issue with PJSIP libraries,

Tried the following in other linker flags in project and able to resolve the error: -framework Foundation -framework UIKit

Above linker flags are used in Siphone Project over github. These settings will help you resolve problems related to linking of C++ libraries.

Answer 19

This fixed my problem: The dependency I am using is not supporting armv7. So I had no other option than to remove it. Armv7 is used for only very old iphones anyway (like iphone 4).

• Go 'Build Settings / All'
• Set 'Valid Architectures' to 'arm64 arm64e'

Answer 20

Finally i've figured it out, I solved this issue by adding absent framework to target->Build Phases->Link Binary With Libraries

Answer 21

I once had this problem. I realized that while moving a class, I had overwritten the .mm file with .h file on the destination folder.

Fixing that issue fixed the error.

Answer 22

I received the 'Undefined symbols for architecture armv7:' error when trying to compile a project that had the target build setting for 'C++ Standard Library' set to 'libc++' (necessary as the project was using some features from C++ 11), and the project included a sub-project that had the same setting set to 'libstdc++' (or compiler default as it is currently).

Changing the sub-project's 'C++ Standard Library' setting to libc++ fixed it, but only after first setting the deployment target for the sub-project to 5.0 or above (5.0 is necessary for libc++).

Answer 23

I give you more suggestions that you can check when other common suggestions are not help.

If you link with other project(libxxx.a) you might sometimes meet strange problem which you can find the symbol with tools like nm but they just can not find the symbols in ld. Then you should check if the two projects are built in the same flags, some of them may affect the binary format.

1. check c++ compiler.
2. check c++ dialect setting.
3. check c++ runtime type support. (-frtti/-fnortti)
4. check if there is .a with the same name appears elsewhere, could be beyond the wanted file in the link path list. remove them.

Answer 24

I got this problem when I run app on iphone5s, it was solved by add arm64 to Architectures.

Answer 25

I had the same problem. I tried every thing from the huge list of answer but in the end my problem was: I'm working with openCV so I need to combine C++ code in my code. To do this you should change the files which use objective-c and C++ to .mm I didn't changed one file and this file has no connection to the C++ code but I had to change it.

Answer 26

I had this issue, when installing shareKit. It worked in the simulator, but not on the device. I removed -all_load from the Other Linker Flag and everything works fine in both simulator and iphone device.

Answer 27

In my case, I'd added a framework that must be using Objective C++. I found this post:

XCode .m vs. .mm

that explained how the main.m needed to be renamed to main.mm so that the Objective-C++ classes could be compiled, too.

That fixed it for me.

Answer 28

I use to face that issue when the module (file .m) is not in the target that I am working with.

Answer 29

For me the problem was that i forget to set value for my constants in the .m (implementation)

file const kFooKey = @"Foo";

Answer 30

I also added files through Dragging and Dropping. What I did, I removed references of all the files (Excluding frameworks) then added them again properly via Add Files To Project option, problem gone.