Finding which file defines extern value - matlab

Question

I am using raspberry PI to run some assembler code on GPU.
It works like this: you assemble the code into binary file. Then you include it into a C code which pushes data into the GPU. This binary file is defined as
extern uint32_t arrayOfCode[];
However I can not find where is this code included(it is not in any other include files).
The whole code can be found here
Upon running makefile it works.
Where the problem comes is when I am trying to build it as MEX function in Matlab.
Matlab cannot find where is the assembler binary code defined. Thus I have a suspicion that it must be linked somehow in Makefile since that's the only difference in building it.
Does anyone has an idea how to find where is this extern value defined ?
==EDIT 1==
I posted my one solution how to build this into a Matlab library.
But the question remains more or less the same. How this makefile
CXX=g++
ASMSRCS := gemm_float.asm
ASMOBJS := $(subst .asm,.do,$(ASMSRCS))
CPPSRCS := $(shell find . -name '*.cpp' -not -name '._*')
CPPOBJS := $(subst .cpp,.o,$(CPPSRCS))
CPPFLAGS=-Ofast -DTARGET_PI -march=armv6 \
-mfloat-abi=hard \
-ftree-vectorize \
-funroll-all-loops \
-mfpu=vfp \
%.cdat: %.asm helpers.asm
m4 $< | qpu-asm -o $(basename $#).cdat -c g_$(basename $#)Code
%.do: %.cdat
$(CXX) $(CPPFLAGS) -x c -c $< -o $(basename $#).do
%.o: %.cpp
$(CXX) $(CPPFLAGS) -fPIC -c $< -o $(basename $#).o
gemm: $(CPPOBJS) $(ASMOBJS)
g++ -g -O3 -o gemm $(CPPOBJS) $(ASMOBJS) -lblas
Could include "gemm_float.asm" assembled code into the C array defined with the keyword extern. I read that these "%." rules in makefile are rules for dependencies. Okay, that would mean that "gemm" would build anew if I changed something in files that "gemm" depends on. Or I might not understand makefiles well enough.

Answer 1

I was able to fix the issue by separately building C code and assembler code. This is for anyone who cannot use an original makefile for some reason(mine was trying to build this into a mex Matlab library).
First, we build code.asm into binary file
m4 code.asm | ./qpu-asm -o code.bin
Now we have to adjust our C code in such a way that it loads .bin code in it's main function. I used a function from eman's tutorial which simply reads the assembler code from a bin file and saves it into an array for later use.
int loadQPUCode(const char *fname, unsigned int* buffer, int len)
{
FILE *in = fopen(fname, "r");
if (!in) {
fprintf(stderr, "Failed to open %s.\n", fname);
return -1;
}
size_t items = fread(buffer, sizeof(unsigned int), len, in);
fclose(in);
return items * sizeof(unsigned int);
}
Then it is enough to call call this before using any gpu related function.
loadQPUCode("asmCode.bin",arrayOfCode,CONSTANT_RELATIVE_TO_ASMCODE);
With this adjusted C code and binary assembler code I was able to build Matlab library using matlab mex function.
mex main.cpp include1.cpp include2.cpp