I have a MATLAB function that has signal processing and machine learning and I wanted to test it on another OS like linux. So I use codegen to generate C code for that function. When I come to run it (predictActivityFromSignalBuffer) on the command line, this is what I get:
MacBook-Pro-2:predictActivityFromSignalBuffer kareem$ gcc predictActivityFromSignalBuffer.c
Undefined symbols for architecture x86_64:
"_featuresFromBuffer", referenced from:
_predictActivityFromSignalBuffer in predictActivityFromSignalBuffer-1a1886.o
"_main", referenced from:
implicit entry/start for main executable
"_mynn", referenced from:
_predictActivityFromSignalBuffer in predictActivityFromSignalBuffer-1a1886.o
"_rtIsNaN", referenced from:
_predictActivityFromSignalBuffer in predictActivityFromSignalBuffer-1a1886.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
What is this error telling me exactly? I have no idea how to debug this or where to start/look.
Did you really just call
$ gcc predictActivityFromSignalBuffer.c
without any other dependencies? Usually there come a lot of other files with a code generation that have to be linked.
I do not know what you have done to produce your .c file. I recommend to use the coder wizard by typing
coder
in the Matlab command window. This will guide you through the whole process of code generation and also offers a lot of support and testing possibilities. You can also choose to compile your functions to ready-to-use DLL libraries or executatables. Just have a look at it.
Related
I have a header file included in the main but when I compile the main, I have an error saying that the linker failed.
I tried to find the object files but I cannot find them.
I think the problem may come from my machine. I am kind of a beginner so I don't know how to solve this
When I try compiling my code I get this error:
Undefined symbols for architecture x86_64:
"_intClassic", referenced from:
_main in main-53b7e4.o
"_intQuadrature", referenced from:
_main in main-53b7e4.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
#zwol #JonathanLeffer I have 3 files in my project main.c, integral.h
and integral.c. integral.c contains the code of the functions
intClassic and intQuadrature that allow me to calculate different
types of integral. In integral.h I declared the functions and
structures I use. Finally in the main I included integral.h .
Also $ gcc -o output file1.o file2.o can this command help me ?
In the same directory as your files, try running the command
gcc main.c integral.c -o integral
This should take the 2 files and compile them into a program called ./integral
I'm rather unused to C, and completely new to compiling bigger projects, and I'm having problems trying to build GNU Archimedes.
I tried the ./configure and make approach, as well as simply executing gcc -lm archimedes.c -o archimedes in the src/ directory, as the documentation suggests. Both give a similar error message:
Undefined symbols for architecture x86_64:
"_MM2", referenced from:
_ParabMEP2D in ccwORAXj.o
_Hole_MEP2D in ccwORAXj.o
"_creation", referenced from:
_EMC in ccwORAXj.o
"_rnd", referenced from:
_MCdevice_config in ccwORAXj.o
_scat in ccwORAXj.o
_EMC in ccwORAXj.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
MM2, rnd, and creation are functions contained in one of many .h files in src/. Every solution to similar sounding problems had issues linking multiple compiled .c files together, but in this case, there's only one .c file.
If it's relevant, the name of the .o file in the error changes with every try.
I've tried building it under macOS (with both clang and gcc, the latter installed via Homebrew) and Fedora Linux, with similar results.
What am I doing wrong? I hope this is the right place to ask, but I have no idea where else to turn. I'm grateful for suggestions.
Thanks in advance and have a good day!
In the folder /archimedes-2.0.1/src/ go through all header files (.h) and change every "inline" to say "static inline".
This fix was found by Alexander Vogt. His original post is linked to below:
https://lists.gnu.org/archive/html/archimedes-discuss/2017-11/msg00000.html
The problem has to do with compatibility issues between older and newer versions of c compilers.
I am trying to compile a very simple C/C++ program to call Julia functions. Following the instructions that you find on the Julia documentation page, I set up my link path to /Users/william.calhoun/Desktop/romeo/lib/julia looking for libjulia.so and I set up my include path to /Users/william.calhoun/Desktop/romeo/include/julia looking for julia.h
I have a C file called test.c which runs the following code:
#include <stdio.h>
#include "skeleton.h"
#include <julia.h>
int main(int argc, const char * argv[]) {
jl_init(NULL);
/* run julia commands */
jl_eval_string("print(sqrt(2.0))");
/* strongly recommended: notify julia that the
program is about to terminate. this allows
julia time to cleanup pending write requests
and run all finalizers
*/
jl_atexit_hook();
return 0;
}
However this yields the following error:
Undefined symbols for architecture x86_64:
"_jl_atexit_hook", referenced from:
_main in test.o
"_jl_eval_string", referenced from:
_main in test.o
"_jl_init", referenced from:
_main in test.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I am not doing anything other than calling functions defined properly (hopefully) within the Julia source code. What am I doing wrong? This seems like the simplest example and I can't figure it out.
Any help would be much appreciated!
Linking to libjulia (libjulia.dynlib on OS/X)
This error is a result of not linking to libjulia, as all of the symbols (_jl_atexit_hook, _jl_eval_string, _jl_init) are located in that library. Broadly, for all 3 of the following platforms (Windows, OS/X, Linux), the approach is similar, and though the location of the libjulia library is different on Windows than the other 2 this stackoverflow question is applicable. Also to be completely accurate, on OS/X, dynamic libraries have the extension .dynlib not .so as they do on Linux.
The link step
For simplicity, assuming you've compiled to object code (there is a file called embed.o), here's the link step.
cc -o embed embed.o -L/Users/william.calhoun/Desktop/romeo/lib/julia -Wl,-rpath,/Users/william.calhoun/Desktop/romeo/lib/julia -ljulia
There are 2 important things to note here.
Linking using -ljulia will allow the linker to resolve all of the above symbols.
Since this is a dynamic library and that dynamic library is located in a non standard location (e.g. not in /usr/lib), the dynamic linker will not be able to find it at run time unless you give it special instructions on how to find it. The -rpath directive causes the linker to insert the path /Users/william.calhoun/Desktop/romeo/lib/juliainto the list of paths to search.
I'm having a problem using min() and max() function in my C project. I've imported math.h, but when I compile the file I keep getting the following error (a similar error is displayed even using gcc instead of llvm):
Undefined symbols for architecture x86_64:
"_min", referenced from:
_main in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I think the problem is that there isn't a 64 bit library of math.h... or the compiler can't find it. I'm using Mac OS X 10.7. How may I fix this problem?
Even though I can see "min" defined in libSystem.dylib, I don't think there's an exported header for that. And I can't figure out where "_min" is coming in from, in terms of the include files.
Normally "min" is referred to with a macro or with your own function. Check out this very related question somebody else asked a while back.
If you look in math.h, there are some "min" type functions in there but they are for floats and doubles. If you are just working with integers or custom types, roll your own function.
I just started learning C, and wrote my hello world program:
#include <stdio.h>
main()
{
printf("Hello World");
return 0;
}
When I run the code, I get a really long error:
Apple Mach-O Linker (id) Error
Ld /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Products/Debug/CProj normal x86_64
cd /Users/Solomon/Desktop/C/CProj
setenv MACOSX_DEPLOYMENT_TARGET 10.7
/Developer/usr/bin/clang -arch x86_64 -isysroot /Developer/SDKs/MacOSX10.7.sdk -L/Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Products/Debug -F/Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Products/Debug -filelist /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Intermediates/CProj.build/Debug/CProj.build/Objects-normal/x86_64/CProj.LinkFileList -mmacosx-version-min=10.7 -o /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Products/Debug/CProj
ld: duplicate symbol _main in /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Intermediates/CProj.build/Debug/CProj.build/Objects-normal/x86_64/helloworld.o and /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Intermediates/CProj.build/Debug/CProj.build/Objects-normal/x86_64/main.o for architecture x86_64
Command /Developer/usr/bin/clang failed with exit code 1
I am running xCode
Should I reinstall DevTools?
If you read the error messages (specifically the line starting ld: duplicate symbol _main in ...), you'll notice that it's complaining about two main functions, one in:
......blah blah blah/helloworld.o
and the other in:
......yada yada yada/main.o
That means your project is screwed up somehow. Either you have two separate source files containing main or Xcode is supplying one automagically.
You just need to fix that.
Here's how to interpret that message:
Apple Mach-O Linker (id) Error
An error occurred
Ld /Users/ …
cd …
setenv …
/Developer/…
This is the command that Xcode executed to perform the linking step. You can almost always ignore it and skip past the next blank line.
ld: duplicate symbol _main in /Users/…/helloworld.o and /Users/…/main.o for architecture x86_64
This is the actual error message. It tells you that you have duplicate _main symbols, one in the file helloworld.o and one in main.o. This means you have to functions which are both called main, which isn't allowed. One of them is in helloworld.c and the other is in main.c. If you delete one of these functions or files, the error will go away.
Command /Developer/usr/bin/clang failed with exit code 1
This tells you the exit code of the command Xcode performed. It is less helpful than the error message, and I have never seen anything other than 1 for linking errors.
I meet this problem as well. In "Target Membership", just tick the file you want to run. Untick this in other files you don't want to run. Then try again.
It is also important to remember that you could have received this error message if you had a #include "...filename..." that created a duplicate copy of your function calls. However, in your case, that is not likely.
remember that #include essentially just copies and pastes a copy of your code where the #include takes place.