Program exited with code -11 when calling

[Cym13]

On Wednesday, 1 July 2020 at 05:04:28 UTC, Anthony wrote:
> I'm trying to convert this c function:
>
> bson_t *bson_new_from_json (const uint8_t *data, ssize_t len, 
> bson_error_t *error);
>
>
> Into a D function. This is my attempt:
> extern(C) {
>     struct bson_t;
>     struct bson_error_t;
>
>     bson_t* bson_new_from_json(const uint8_t* data, long len, 
> bson_error_t* error);
> }
>
> However when I try it, for example:
>
> auto str_utf8 = str.toUTF8();
> bson_error_t error
>
> auto bson = bson_new_from_json(cast(const 
> uint8_t*)str_utf8.ptr, -1, &error);
>
>
> I get a "Program exited with code -11" message.
> Does anyone know what I'm doing wrong?
>
> Thanks

I don't know the exact function you are trying to use, but -11 
means "segmentation fault" on linux. This means that your program 
is trying to read or write a memory location that it is not 
supposed to. This typically happens during buffer overflows and 
similar memory corruption bugs.

One thing that jumps to me is the -1 in your call instead of the 
length. Without knowing the C function's implementation I would 
expect it to mean either "read before the array" which would be a 
buffer overflow or to have the special meaning of "deduce the 
string size yourself". In that last case I would expect 
bson_new_from_json to expect a NUL-terminated array, but I don't 
know if your UTF8 array is NUL-terminated.