A friend of mine asked me to re-write Box2D in objective-c as much as possible. I started writing and when I build the project so far I got, I got some linker errors, I faced similar problem from before, but it didn't help. The error I get is:
Ld /Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Products/Debug/Obj-Box2D normal x86_64
cd /Users/aizen-qa/Desktop/Obj-Box2D
setenv MACOSX_DEPLOYMENT_TARGET 10.9
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk -L/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Products/Debug -F/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Products/Debug -filelist /Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Obj-Box2D.LinkFileList -mmacosx-version-min=10.9 -fobjc-arc -fobjc-link-runtime -framework Foundation -Xlinker -dependency_info -Xlinker /Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Obj-Box2D_dependency_info.dat -o /Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Products/Debug/Obj-Box2D
duplicate symbol _Ob2IsValid in:
/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Ob2Vec3.o
/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Ob2Mat22.o
duplicate symbol _Ob2InvSqr in:
/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Ob2Vec3.o
/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Ob2Mat22.o
duplicate symbol _Ob2IsValid in:
/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Ob2Vec3.o
/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Ob2Vec2.o
duplicate symbol _Ob2InvSqr in:
/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Ob2Vec3.o
/Users/aizen-qa/Library/Developer/Xcode/DerivedData/Obj-Box2D-bwsosdvwkjzsscahpbqrbrnzlall/Build/Intermediates/Obj-Box2D.build/Debug/Obj-Box2D.build/Objects-normal/x86_64/Ob2Vec2.o
ld: 4 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I've read of similar problems, and tried the solutions such as checking the imports not use .m, and duplicate variable names. But I noticed that the classes of vector have same instance variable names, x, y so is this the reason for the error I'm getting or not?
You have data elements being defined, rather than declared, in multiple implementation files. This is usually because of something in an included header.
Look for wherever you reference Ob2InvSqr or Ob2IsValid and make sure that storage for those items is only done once.
the file Ob2Vec2.o and Ob2Vec3.o contain the same symbol _Ob2InvSqr
very likely that means you have both Ob2Vec2.m and Ob2Vec3.m in the same target.
make sure only one is really compiled
I guess you have an inline function _Ob2IsValid(...) in one of your header files that isn't being inlined (it's too large?)
If that's the case you can force it to be inlined like this:
__attribute__((always_inline)) inline void MyFunction(...) {}
Or just make it out-of-line
I was able to solve this thanks to a comment form MartinR. It was because I defined a function in a .h file that I included in multiple Objective-C classes. So what I did was put the function header in the .h file and its implementation in a .m file.
Related
duplicate symbol _GTMNSDictionaryURLArgumentsExportToSuppressLibToolWarning in:
/Users/Varshana/Library/Developer/Xcode/DerivedData/Lodore-axtsfmjdyxbqyccujoquacrynsxv/Build/Products/Debug-iphonesimulator/GoogleToolboxForMac/libGoogleToolboxForMac.a(GTMNSDictionary+URLArguments.o)
/Users/Varshana/Documents/Lodore final stage/GoogleSignInDependencies.framework/GoogleSignInDependencies(GTMNSDictionary+URLArguments_aec9c2446af4c2ac5a7380b418b337ea.o)
duplicate symbol _kGTMOAuth2WebViewKey in:
/Users/Varshana/Library/Developer/Xcode/DerivedData/Lodore-axtsfmjdyxbqyccujoquacrynsxv/Build/Products/Debug-iphonesimulator/GTMOAuth2/libGTMOAuth2.a(GTMOAuth2Authentication.o)
/Users/Varshana/Documents/Lodore final stage/GoogleSignInDependencies.framework/GoogleSignInDependencies(GTMOAuth2Authentication_ad53759ab562393658e6c193e56628dd.o)
duplicate symbol _kGTMOAuth2ErrorRequestKey in:
/Users/Varshana/Library/Developer/Xcode/DerivedData/Lodore-axtsfmjdyxbqyccujoquacrynsxv/Build/Products/Debug-iphonesimulator/GTMOAuth2/libGTMOAuth2.a(GTMOAuth2Authentication.o)
/Users/Varshana/Documents/Lodore final stage/GoogleSignInDependencies.framework/GoogleSignInDependencies(GTMOAuth2Authentication_ad53759ab562393658e6c193e56628dd.o)
don't worry, just xcode bug. try clean and build and it will work, or better, go to xcode->preferences->location->Derived Data. delete all files inside derived data and then restart xcode. clean and build the project and then it will work perfectly
ps: updated for cleaning
Cmd + Shift + Alt + K
To check the exact error for this issue check following:
Select issue navigator > Click on error will show logs for error > In that select All Messages tab.
75 duplicate symbols for architecture x86_64
Means that you have loaded same functions twice. As the issue disappear after removing -ObjC from Other Linker Flags, this means that this option result that functions loads twice:
from Technical Q&A
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.
https://developer.apple.com/library/content/qa/qa1490/_index.html
I've been reading up on various linker errors on Stack Overflow for awhile now, and each seem to be a bit different. I'm hoping you might have insight into the one I'm getting.
I've got the following... (issue only exists in simulator. It's fine on device.)
Apple Mach-O Linker Error
ld: 192 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
There are 2 errors for every file...
duplicate symbol _CATEGORIES in:
/Users/me/Library/Developer/Xcode/DerivedData/Roto_Forum-ahulcvyneocizdcbjsdtiqgknlhk/Build/Intermediates/Roto Forum.build/Debug-iphonesimulator/Roto Forum.build/Objects-normal/x86_64/FFFMainBodyViewController.o
/Users/me/Library/Developer/Xcode/DerivedData/Roto_Forum-ahulcvyneocizdcbjsdtiqgknlhk/Build/Intermediates/Roto Forum.build/Debug-iphonesimulator/Roto Forum.build/Objects-normal/x86_64/Item.o
duplicate symbol _POINTS in:
/Users/me/Library/Developer/Xcode/DerivedData/Roto_Forum-ahulcvyneocizdcbjsdtiqgknlhk/Build/Intermediates/Roto Forum.build/Debug-iphonesimulator/Roto Forum.build/Objects-normal/x86_64/FFFMainBodyViewController.o
/Users/me/Library/Developer/Xcode/DerivedData/Roto_Forum-ahulcvyneocizdcbjsdtiqgknlhk/Build/Intermediates/Roto Forum.build/Debug-iphonesimulator/Roto Forum.build/Objects-normal/x86_64/Item.o
That's 2 of the 192 errors. If I look at my Compile Sources under the Build Phases of my Target, FFFMainBodyViewController.m is the first file. Item.m is the second. And for each and every file down the list, in order, I get a 2 duplicate errors like the ones seen above.
This all started I believe when I renamed my project, and therefore the target name in my Podfile also changed.
I've tried various things. Deleting Derived Data, Cleans, deleting the red libPods.a file from my framework, etc.
How might I solve this issue?
I installed the CodeSourcery g++ toolchain and tried to compile a simple hello world program:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello World" << endl;
return 0;
}
And got a lot of errors from the linker
$ arm-none-eabi-g++ helloworld.cpp -o helloworld.exe
bin/ld: warning: cannot find entry symbol _start; defaulting to 0000000000008018
lib/libc.a(lib_a-abort.o): In function `abort':
abort.c:(.text.abort+0x10): undefined reference to `_exit'
lib/libc.a(lib_a-fstatr.o): In function `_fstat_r':
fstatr.c:(.text._fstat_r+0x1c): undefined reference to `_fstat'
lib/libc.a(lib_a-openr.o): In function `_open_r':
openr.c:(.text._open_r+0x20): undefined reference to `_open'
lib/libc.a(lib_a-sbrkr.o): In function `_sbrk_r':
sbrkr.c:(.text._sbrk_r+0x18): undefined reference to `_sbrk'
lib/libc.a(lib_a-signalr.o): In function `_kill_r':
signalr.c:(.text._kill_r+0x1c): undefined reference to `_kill'
lib/libc.a(lib_a-signalr.o): In function `_getpid_r':
signalr.c:(.text._getpid_r+0x4): undefined reference to `_getpid'
lib/libc.a(lib_a-writer.o): In function `_write_r':
writer.c:(.text._write_r+0x20): undefined reference to `_write'
lib/libc.a(lib_a-closer.o): In function `_close_r':
closer.c:(.text._close_r+0x18): undefined reference to `_close'
lib/libc.a(lib_a-isattyr.o): In function `_isatty_r':
isattyr.c:(.text._isatty_r+0x18): undefined reference to `_isatty'
lib/libc.a(lib_a-lseekr.o): In function `_lseek_r':
lseekr.c:(.text._lseek_r+0x20): undefined reference to `_lseek'
lib/libc.a(lib_a-readr.o): In function `_read_r':
readr.c:(.text._read_r+0x20): undefined reference to `_read'
collect2: ld returned 1 exit status
What library am I missing here?
The GCC toolchain is only half of what you need to create a working executable*. The other half is the runtime library. The runtime includes crt0.o, which contains the entry point (the code that calls main()), and generally a libc that contains the standard C functions (strcmp(), memcpy(), etc) as well as the system calls (open(), read(), and others). You need to find a source for these. If you're targeting an embedded Linux or BSD machine, you'll have to find out what libc your target is using. It's probably either GNU libc, BSD libc, newlib, or uclibc. You can get these and build them yourself, or they may be available already with your OS.
*unless you're building a freestanding binary, but this doesn't look to be what you're doing.
Basing on the cross compiler it appears that end target is bare metal. The default gcc libraries (OS dependent) will not work here. You can use the NewlibC or NewlibC-Nano. This generally will be shipped along with the cross compiler tool chain.
Look for lib folder which has precompiled NewlibC.
Once that is done,
This statement might help you to an extent.
arm-none-eabi-gcc --specs=rdimon.specs \
-Wl,--start-group -lgcc -lc -lc -lm -lrdimon -Wl,--end-group $(OTHER_OPTIONS)
Don't forget to provide the path of looking the libraries -L(path).
I had this same problem.
It turns out there are a handful of options you can send to the linker to make it start working, but the one that had the least splash damage in my code base was
-nostartfiles
I'got a problem with compiling linking of a program with multiple files by g++ (I usually use vstudio, but...).
If I use only main.cpp (and include appropriate header files for openCV), everything is ok with
g++ main.cpp -o main -I"C:\OpenCV2.1\include\opencv" -L"C:\OpenCV2.1\lib"
-lcxcore210 -lcv210 -lhighgui210
If I have main.cpp and some otherfile.cpp (both need openCV) and use
g++ main.cpp otherfile.cpp -o main -I"C:\OpenCV2.1\include\opencv"
-L"C:\OpenCV2.1\lib" -lcxcore210 -lcv210 -lhighgui210
it simply doesn't work and I got
c:/mingw/bin/../lib/gcc/mingw32/4.5.0/../../../../mingw32/bin/ld.exe: warning: a
uto-importing has been activated without --enable-auto-import specified on the c
ommand line.
This should work unless it involves constant data structures referencing symbols
from auto-imported DLLs.
C:\Users\ONDEJM~1\AppData\Local\Temp\ccNisCoC.o:main.cpp:(.text+0x16d0): undefin
ed reference to `cv::Mat::Mat(_IplImage const*, bool)'
C:\Users\ONDEJM~1\AppData\Local\Temp\ccNisCoC.o:main.cpp:(.text+0x16f1): undefin
ed reference to `cv::FAST(cv::Mat const&, std::vector<cv::KeyPoint, std::allocat
or<cv::KeyPoint> >&, int, bool)'
C:\Users\ONDEJM~1\AppData\Local\Temp\ccNisCoC.o:main.cpp:(.text$_ZN2cv3Mat7relea
seEv[cv::Mat::release()]+0x3f): undefined reference to `cv::fastFree(void*)'
collect2: ld returned 1 exit status
What am I doing wrong?
Pass "-Wl,--enable-auto-import" to g++. Read ld's documentation about this.
Hm, it seems that I made a silly mistake... solution is simple: just recompile all openCV binarries by g++ and everything will be ok!
I'm trying to compile a project that uses both libjpeg and libpng. I know that libpng needs zlib, so I compiled all the three independently and put them (libjpeg.a, libpng.a and libz.a) on a folder called linrel32. What I execute then is:
g++ -Llinrel32/ program.cpp otherfile.cpp -o linrel32/executable -Izlib/ -Ilpng140/ -Ijpeg/ -lpthread -lX11 -O2 -DLINUX -s -lz -lpng -ljpeg
So I include the three libraries. Still, the linker complains:
linrel32//libpng.a(png.o): In function `png_calculate_crc':
png.c:(.text+0x97d): undefined reference to `crc32'
linrel32//libpng.a(png.o): In function `png_reset_crc':
png.c:(.text+0x9be): undefined reference to `crc32'
linrel32//libpng.a(png.o): In function `png_reset_zstream':
png.c:(.text+0x537): undefined reference to `inflateReset'
linrel32//libpng.a(pngread.o): In function `png_read_destroy':
pngread.c:(.text+0x6f4): undefined reference to `inflateEnd'
linrel32//libpng.a(pngread.o): In function `png_read_row':
pngread.c:(.text+0x1267): undefined reference to `inflate'
linrel32//libpng.a(pngread.o): In function `png_create_read_struct_2':
(... you get the idea :D)
collect2: ld returned 1 exit status
I know the missing functions are from zlib, and I'm adding zlib there. Opened libz.a and it seems to have a good structure. Recompiled it, everything looks fine. But it is not...
I don't know, is likely that the problem is trivial, and what I need is to sleep for a while. But still, if you could help me to figure out this thing ...
You need to rearrange the order of the libraries:
-lpng -ljpeg -lz
What is happening is that the linker has special rules on how it treats static libraries. What it does is that it only includes a .o from inside the .a if the .o is needed to satisfy a reference.
Furthermore, it handles static archives in the order in which they appear on the link line.
So, your code does not directly call any functions in zlib. So when the linker handles -lz first, there are not yet any calls to it so it doesn't pull in any of zlib.
Next, when the linker handles libpng, it sees that there are calls to it from your code. So it pulls the code from libpng and since it makes calls to zlib, now there are references to the zlib functions.
Now you come to the end of your libraries and there are unsatisfied calls which causes your error.
So, if libhigh.a makes use of liblow.a, you must have -lhigh before -llow in your link order.
you probably need to surround the zlib and png headers with extern "C", e.g.:
extern "C" {
#include <zlib.h>
}