A Reusable CUDA_CHECK Macro
Wrapping every call for safety.
A Reusable CUDA_CHECK Macro is a free CUDA Academy lesson on CoddyKit — lesson 3 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the CUDA Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Checking Every Call Is Tedious
Writing an if-statement after every CUDA call clutters your code fast. A reusable CUDA_CHECK macro fixes that with one clean line. 🧹
The Goal of the Macro
You want to wrap any call, grab its return code, and bail out loudly if it failed. One macro can do this everywhere.
CUDA_CHECK(cudaMalloc(&d, n));Capturing the Result
Inside, the macro stores the call result in a local cudaError_t so it can be inspected once without calling twice.
cudaError_t e = (call);Comparing to Success
It then tests the code against cudaSuccess. If they match, nothing happens and your program flows on as normal.
if (e != cudaSuccess) { /* report */ }Printing Where It Failed
On failure it prints a readable message using __FILE__ and __LINE__, so you jump straight to the offending line.
printf("CUDA error %s at %s:%d\n", msg, __FILE__, __LINE__);The do-while(0) Trick
The body is wrapped in a do-while(0). This makes the macro a single statement that works safely even inside an unbraced if.
#define CUDA_CHECK(c) do { /* ... */ } while(0)A Full Macro Sketch
Put it together and you get a compact, reusable safety net you can paste into any CUDA project header.
#define CUDA_CHECK(c) do { cudaError_t e=(c); if(e) exit(1); } while(0)Wrapping API Calls
Use it on any call that returns a code: cudaMalloc, cudaMemcpy, cudaFree. One wrapper guards them all uniformly.
CUDA_CHECK(cudaMemcpy(d, h, n, cudaMemcpyHostToDevice));Also Guard the Launch
Kernels return nothing, so wrap cudaGetLastError and a sync after the launch instead of wrapping the launch line itself.
kernel<<<g, b>>>();
CUDA_CHECK(cudaGetLastError());Keep It in a Header
Drop the macro in a shared header so every file uses the same check. Consistency here saves hours of confusing debugging.
Fail Fast, Fail Clearly
The big win is failing fast: the instant a call breaks, you get a precise file, line, and message instead of silent garbage.
Quick Check
Test your grasp of the CUDA_CHECK macro.
Recap: One Macro to Guard Them All
A CUDA_CHECK macro captures the code, compares to success, and prints file and line on failure. Define it once, use it everywhere. 🎉
Frequently asked questions
Is the “A Reusable CUDA_CHECK Macro” lesson free?
Yes — the full text of “A Reusable CUDA_CHECK Macro” is free to read here on the web, and the CUDA Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the CUDA Academy course, upgrade to CoddyKit PRO.
What will I learn in “A Reusable CUDA_CHECK Macro”?
Wrapping every call for safety. You practise CUDA Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start CUDA Academy?
No prior experience is required. CUDA Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 3 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “A Reusable CUDA_CHECK Macro” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this CUDA Academy lesson?
Yes. Every CUDA Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Return Codes vs Async Errors
- cudaGetLastError After Launch
- A Reusable CUDA_CHECK Macro
- Decoding cudaGetErrorString