Pragma msg goes out of memory when supplied with large data.

[Dennis]

On Friday, 23 May 2025 at 12:06:00 UTC, realhet wrote:
> - export: It was possible to export data (20MByte) from the 
> compiler in seconds, using pragma(msg, ...)  Just don't touch 
> the large data with CTFE.

pragma(msg) is meant to print informative human-readable strings 
for debugging purposes. It's not designed for large data or 
consistent results. A pull request to the compiler improving the 
formatting of a pragma(msg) might break your setup.

Please carefully consider whether a convoluted build system is 
worth it. I've done some cute GLSL+D metaprogramming as well in 
the past with the goal to automatically bind uniforms and vertex 
attributes between the two languages seamlessly, but I'm not 
using it anymore because the impedance mismatch is too high.

I'm talking: Different alignments (std140 and std430), booleans 
are 4 bytes, normalized and packed integers need special types on 
the D side, vec3 and float[3] both exist in OpenGL, there's 36 
sampler types, OpenGL's reflection API has holes (you can't query 
the pixelformat from `layout(binding=2, rg32f)`), column/row 
major matrix layout etc.

This results in a complex system that's more annoying to deal 
with than the original problem of just maintaining a .d file and 
shader file in parallel, which is what I'm doing now for the time 
being.



... but if that didn't scare you off, you can use `__ctfeWrite` 😉

```D
string f(string s) { __ctfeWrite(s); return s; };
enum x = f("Hello world\n"); // prints "Hello World\n" to stderr
```

I recommend keeping it simple, cover common cases and don't try 
to make it perfect, because it won't be. But if you do somehow 
make it perfect, post your results, I'd love to see it!