#include "sys.h"
#include "macros.h"
#include <sys/mman.h>
#include <stdarg.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

void *sys_alloc(u64 length)
{
	assert(length);
	i32 prot = PROT_READ | PROT_WRITE;
	i32 flags = MAP_PRIVATE|MAP_ANONYMOUS;
	void *result = mmap(0, length, prot, flags, -1, 0);
	return result;
}

void sys_free(void *memory, u64 length)
{
	assert(memory);
	assert(length);
	munmap(memory, length);
}

void die(const char *format, ...)
{
	va_list args;
	va_start(args, format);
	fprintf(stderr, "error: ");
	vfprintf(stderr, format, args);
	fprintf(stderr, "\n");
	va_end(args);
	_exit(1);
}

void info(const char *format, ...)
{
	va_list args;
	va_start(args, format);
	vprintf(format, args);
	putchar('\n');
	va_end(args);
}

char *read_entire_file(struct arena *arena, u64 *len, const char *filename)
{
	FILE *file = fopen(filename, "rb");
	if (!file)
		return 0;
	if (fseek(file, 0, SEEK_END) == -1)
		goto error;
	i64 n = ftell(file);
	if (n <= 0)
		goto error;
	if (len)
		*len = n;
	if (fseek(file, 0, SEEK_SET) == -1)
		goto error;
	char *buffer = push_arena(arena, n + 1);
	if (!fread(buffer, 1, n, file)) {
		pop_arena(arena, n + 1);
		goto error;
	}
	fclose(file);
	buffer[n] = 0;
	return buffer;
error:
	fclose(file);
	return 0;
}