I've included an OpenCL kernel (.cl file) in my OS X framework, and I'm able to reference it from one of my implementation (.m) files.
However, when I compile, I get the following error, related with the kernel:
openclc: error: cannot specify -o when generating multiple output files
This error appears once for every architecture found in the OPENCL_ARCHS build option. I've tried to leave all but one architecture (gpu_64 or gpu_32, tried both), however the error persists.
I went through two examples offered by Apple (Hello World and n-Body simulation, both of which compile and run fine on my system), looking for any special build options, but I failed to find any.
Any thoughts?
Thanks.
EDIT: Added Xcode7 tag, as I am working in Xcode 7 Beta.
Related
I'm a *nix user, installing LLVM is easy for me, just download the precompiled file, set LLVM_DIR, and you're done. But I'm having a lot of problems with Windows ...
I downloaded LLVM-<version>-win64.exe from the GitHub release, but I can't find LLVMConfig.cmake file. Then I tried to compile LLVM from the source following this documentation.
When I started compiling my own project, I got this error:
'C:/<...>/Debug/libLLVMSupport.lib', needed by '<...>.exe', missing and no known rule to make it
I guess maybe I'm missing some compile options. but I can't find the documentation for LLVM_ENABLE_PROJECTS or BUILD_SHARED_LIBS, not even a list of component names.
I tried to add -DBUILD_SHARED_LIBS=ON but CMake told me BUILD_SHARED_LIBS option is not supported on Windows.
What does it mean to have undefined symbols?
There are no errors in the code files themselves and I am NOT using any external libraries.
I DID add a typedef NS_ENUM prior to this linker error occurring.
Where do I add this -v to see invocation?
Here is the error message:
Undefined symbols for architecture x86_64:
"_OBJC_IVAR_$_UIViewController._parentViewController", referenced from:
-[PEPI_LessonController setParentViewController:] in PEPI_LessonController.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
"Undefined Symbols"
Building source code files to an executable file consist of at least two steps:
Compile the source code files to intermediate binary files (often called xyz.o).
Link the intermediate binary files to the final executable file.
The error message "undefined symbols" is a linker message. It may appear even though the compilation process was successful without notice. The linker organizes final memory address relations and it replaces symbols that the compiler had to assume they would be valid later, if all parts of the code would be available. Without this, no modularization would be possible at all.
-v to see invocation
If you build your application in Xcode, then Xcode calls all the compile and link commands for you (CompileC, Ln, Clang ...). But remember that a typical IDE runs only the commands you could run by yourself in the shell. Theoretically, you could develop big applications only in a text editor and a shell. So I suggest take some time and try to copy paste some commands listed in the Xcode build report to a shell :-) You'll learn a lot about the backgrounds. Therefore, in my opinion, -v to see invocation is used while invoking the command in the shell - or in the build settings, if you wish permanently more information.
"External libraries"
Finally, try to clarify "external libraries". To look at the most simple example: even if you write a simple C program and you want to know something trivial like the length of a string, you'll include <glibc.h>. Now this is an external library. It's external to your program code. Are you sure you haven't included external libraries?
Solving linker problems
Linker errors are often confusing and somehow difficult, because details of the linked modules tend to be out of sight. You may find many hints if you enter the error message in a search engine. For example, have a look at here:
Undefined symbols for architecture armv7: "_SCNetworkReachabilityCreateWithAddress"
Even if all components are found for linking, all paths are known etc, they may have the wrong version or else.
It means it can't find the property parentViewController and method setParentViewController when linking your object files files. The most common cause for these types of errors is not linking a library or framework in your projects target. UIViewController is part of UIKit so I'd be surprised if it's not already linked. Is this an OSX project and your trying to use UIViewcontroller instead of NSViewController?
In my case I had forgotten to add the .m file to all the same targets as the .h and that's what caused this issue. In case it helps anyone thought I'd mention here... double check your target memberships!
I followed the Linux build instructions and when I try running "ninja -C out/Debug chrome", I just get the output "Illegal Instruction (core dumped)". Now, I wish I could actually find where the core dump is located to see if there is more specific information in there...
For reference, I am trying to run Ninja on Ubuntu 13.10.
Has anyone else experienced this while building Chromium or while trying to build anything else using Ninja? Also, where could I find the core dump?
The error message "Illegal Instruction (core dumped)" indicates that the current binary is using an instruction that is not supported by your CPU.
Please check whether software used for compilation (compiler, linker, ar, ninja-build etc.) is matching your CPU architecture. Unless you have no fancy system like ARM or POWER, you mixed up 32 bit (e.g. i586) and 64 bit (x86-64).
Or you compile to a wrong target. Does your compiler flags include flags beginning with -m like "-march="? That could lead to the same error but only if the compiled code is executed.
Have you built gyp or ninja-build yourself? This would be an other place to make such a mistake.
I am am trying to cross-compile an x86 program for alpha using g++. For that, I tried both "-static-libgcc" and "--static" options when linking the object file with libraries to generate the binaries. The cross compilation was successful, however I got the following errors when I ran the binaries on alpha machine:
./word_count: /lib/libc.so.6.1: version GLIBC_2.4' not found (required by ./word_count)
./word_count: /usr/lib/libstdc++.so.6: versionGLIBCXX_3.4.10' not found (required by ./word_
These errors shouldn't happen, since I am using static linking! So, I cannot figure out why I am getting these errors! Any help is appreciated.
You need to link against both, standard C and C++ libraries. (source)
When I try to run my application in the iOS 4.3 simulator (Xcode 4.2), I crash when I hit #autoreleasepool{}, with:
dyld: lazy symbol binding failed: Symbol not found: _objc_autoreleasePoolPush
I looked around, and I see the workaround is to add libarclite_iphoneos.a. There's a version of this for the simulator, too, as libarclite_iphonesimulator.a.
I need to add both libraries to my project to make it run on both the simulator and hardware. But whichever I build, it complains that the other library is for an unsupported architecture.
For example, building for simulator:
ld: warning: ignoring file /Developer-4.2/Platforms/iPhoneOS.platform/
Developer/usr/lib/arc/libarclite_iphoneos.a, missing required architecture
i386 in file
How do I fix both of these simultaneously? Or should I just stick with the old NSAutoreleasePool syntax for now?
After a trials like clean, clean folder, resetting iPhone Simulator and even a restart, I changed the IPHONE_DEPLYMENT_TARGET on the target build setting down from iOS 5.0 to iOS 4.2.
Worked.
You can use the Other Linker Flags build setting to link in the library, and specialize the value based on whether it's "Any iOS" or "Any iOS Simulator".
You can also merge the two static libraries to one universal library. Go to the Terminal and say
lipo -create -output /where/you/want/it/libarclite_universal.a /Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/arc/libarclite_iphoneos.a /Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/arc/libarclite_iphonesimulator.a
You can verify the resulting file by saying (in Terminal)
file /where/you/put/it/libarclite_universal.a
It should output:
libarclite_universal.a: Mach-O universal binary with 3 architectures
libarclite_universal.a (for architecture i386):current ar archive random library
libarclite_universal.a (for architecture armv6):current ar archive random library
libarclite_universal.a (for architecture armv7):current ar archive random library
Since this lib is linked statically, your final app wont grow because of the included sim library since only whatever is needed by your app will get linked into your final app.