Very clever compiling error with mangling

[mesni]

On Saturday, 4 June 2022 at 20:22:31 UTC, kinke wrote:
> On Saturday, 4 June 2022 at 20:09:45 UTC, mesni wrote:
>> ```
>> source\api.d(6,5): Error: Function type does not match 
>> previously declared function with the same mangled name: 
>> `_D3api8testFuncFiiZi`
>> source\api.d(6,5):        Previous IR type: void ()
>> source\api.d(6,5):        New IR type:      i32 (i32, i32)
>> ```
>
> The D snippet you posted has apparently nothing to do with the 
> error. It's complaining about 2 different signatures (in 
> different modules) for some `int api.testFunc(int, int)`, with 
> one being a `void()` (and so definitely not matching the 
> mangled signature). Likely an incompatible signature in an 
> `api.di`.

This is a fragment of the string from which the function is 
generated.

```d
mixin({
     import std.array;
     string result = q{
         __gshared extern(C) static void* dpford_funcp_DMANGLE;
         pragma(mangle, "DMANGLE")
         void dpford_func_DMANGLE() {
             asm{
                 naked;
                 jmp dpford_funcp_DMANGLE;
             }
         }
     };
     return result.replace("DMANGLE", n.mangleof);
}());
```
The function declarations themselves
```d
In api.di

module api;

enum SorrelAPI;

@SorrelAPI
int testFunc(int, int);
```

The other module in the mixin template reads all the changled 
function names from that module.