How can Poplar codelets include code from other header files? - ipu

Question

Is it possible for codelets to reference code in other files, like header files?
If I have a codelet file
//FileA.cpp
#include "FileB.h"
class SomeCustomVertex : public Vertex {
public:
bool compute() {
int a = SomeConstantDefinedInFileB;
}
...
}
and some other "codelet" file
//FileB.h
const int SomeConstantDefineInFileB = 42;
and in the host graph program:
graph.addCodelets({"codelets/FileA.cpp", "codelets/FileB.h"});
I get a compile error from popc:
fatal error: 'FileB.h' file not found
#include "FileB.h"
^~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
terminate called after throwing an instance of 'poplar::graph_program_compilation_error'
what(): Codelet compilation failed (see compiler output for details)

Answer 1

I figured this out.
Graph::addCodelets has a parameter StringRef compileFlags = "", which you can use to inject compiler options.
popc --help shows an option
-I arg Add directory to include search path
So when I use graph.addCodelets({"codelets/FileA.cpp"}, "-I codelets"); in the host program, and have my codelets in 'codelets' subdirectory, this works. No need to explicitly list the ".h" files in the arguments.
Incidentally, also a good way to ensure compiler optimisation (-O3) for the custom codelets.