Question

I’ve just started CUDA programming and it’s going quite nicely, my GPUs are recognized and everything. I’ve partially set up Intellisense in Visual Studio using this extremely helpful guide here:
http://www.ademiller.com/blogs/tech/2010/10/visual-studio-2010-adding-intellisense-support-for-cuda-c/

and here:
http://www.ademiller.com/blogs/tech/2011/05/visual-studio-2010-and-cuda-easier-with-rc2/

However, Intellisense still doesn’t pick up on kernel calls like this:

// KernelCall.cu
#include <iostream>
#include "cuda.h"
#include "cuda_runtime.h"
#include "device_launch_parameters.h"

__global__ void kernel(void){}

int main()
{
    kernel<<<1,1>>>();

    system("pause");
    return 0;
}

The line kernel<<<1,1>>>() is underlined in red, specifically the one arrow to the left of the first one with the error reading “Error: expected and expression”. However, if I hover over the function, its return type and parameters are displayed properly. It still compiles just fine, I’m just wondering how to get rid of this little annoyance.

Answer 1

Visual Studio provides IntelliSense for C++, the trick from the rocket scientist’s blog is basically relying on the similarity CUDA-C has to C++, nothing more.

In the C++ language, the proper parsing of angle brackets is troublesome. You’ve got < as less than and for templates, and << as shift, remember not long ago when we had to put a space in between nested template declarations.

So it turns out that the guy at NVIDIA who came up with this syntax was not a language expert, and happened to choose the worst possible delimiter, then tripled it, well, you’re going to have trouble. It’s amazing that Intellisense works at all when it sees this.

The only way I know to get full IntelliSense in CUDA is to switch from the Runtime API to the Driver API. The C++ is just C++, and the CUDA is still (sort of) C++, there is no <<<>>> badness for the language parsing to have to work around.