Re: Generating struct members from c structs

[Simen Kjærås via Digitalmars-d-learn]

On Wednesday, 1 July 2020 at 07:26:44 UTC, Anthony wrote:
When doing interop with a c library, is there a way to 
automatically generate the fields that are needed for a struct?

[snip]

Is there an easier way though?


Dstep is probably what you're looking for: 
https://github.com/jacob-carlborg/dstep


It eats C header files and creates appropriate D files from them.

--
  Simen

Generating struct members from c structs

[Anthony via Digitalmars-d-learn]

When doing interop with a c library, is there a way to 
automatically generate the fields that are needed for a struct?


For example, when interfacing with the lwan c library:

// lwan.h
struct lwan {
struct lwan_trie url_map_trie;
struct lwan_connection *conns;
struct lwan_strbuf headers;

struct {
pthread_barrier_t barrier;
struct lwan_thread *threads;
unsigned int max_fd;
unsigned int count;
} thread;

struct lwan_config config;
struct coro_switcher switcher;

int main_socket;

unsigned int n_cpus;
};

module lwan;

extern (C) {
struct lwan {
  ... // <<< How do I populate this without having to write 
all the sub structs?

};
void lwan_init(lwan* l);
void lwan_shutdown(lwan* l);
}

import lwan;

void main() {
  lwan l; //This is currently not allocating enough memory
  lwan_init(&l);
  lwan_shutdown(&l);
}

How do I populate the lwan struct without having to write all the 
sub structs?


I'm thinking that maybe it'll be best to create a wrapper c 
function that initializes the lwan struct and returns a pointer.


That way I don't have to declare any fields.

extern (C) {
struct lwan;

lwan* lwan_make(); //wrapper function (perhaps in wrapper.c)
void lwan_cleanup(lwan* l); //wrapper function

void lwan_init(lwan* l);
void lwan_shutdown(lwan* l);
}

Is there an easier way though?