roc/crates/bindgen/templates/template.c

#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

void* roc_alloc(size_t size, unsigned int alignment) { return malloc(size); }

void* roc_realloc(void* ptr, size_t new_size, size_t old_size, unsigned int alignment) {
  return realloc(ptr, new_size);
}

void roc_dealloc(void* ptr, unsigned int alignment) { free(ptr); }

void roc_panic(void* ptr, unsigned int alignment) {
  char* msg = (char*)ptr;
  fprintf(stderr,
          "Application crashed with message\n\n    %s\n\nShutting down\n", msg);
  exit(0);
}

void* roc_memcpy(void* dest, const void* src, size_t n) {
  return memcpy(dest, src, n);
}

void* roc_memset(void* str, int c, size_t n) { return memset(str, c, n); }

///////////////////////////////////////////////////////////////////////////
//
// roc_std
//
///////////////////////////////////////////////////////////////////////////

struct RocStr {
  char* bytes;
  size_t len;
};

bool is_small_str(struct RocStr str) { return ((ssize_t)str.len) < 0; }

// Determine the length of the string, taking into
// account the small string optimization
size_t roc_str_len(struct RocStr str) {
  char* bytes = (char*)&str;
  char last_byte = bytes[sizeof(str) - 1];
  char last_byte_xored = last_byte ^ 0b10000000;
  size_t small_len = (size_t)(last_byte_xored);
  size_t big_len = str.len;

  // Avoid branch misprediction costs by always
  // determining both small_len and big_len,
  // so this compiles to a cmov instruction.
  if (is_small_str(str)) {
    return small_len;
  } else {
    return big_len;
  }
}