Loki CivCTP function wrapper

civctp_wrapper.c

// Step 1: Hex-Edit the civctp.dynamic executable
// - Rename the libSDL import to point to SDL 1.2
// - Rename all the functions below in the import tables:
//   - __builtin_new → x_builtin_new (etc.)
//   - {mem,str,strn}cpy → {mem,str,strn}cpx
// - Make sure you have libttf and libsmpeg in the current directory
// - Build this with:
//    cc -shared -m32 -fPIC -o libcivctp_wrapper.so civctp_wrapper.c
// - Run CivCTP with:
//    LD_PRELOAD=libcivctp_wrapper.so LD_LIBRARY_PATH=. ./civctp.dynamic
// - Beware of bugs:
//   - It'll probably corrupt memory and crash all the time. :/
//     (Changing the malloc(x) → calloc(x, 2) fixes some of these, I think, but…)
//   - It doesn't work properly with sdl12-compat yet
//   - Multiplayer likely still won't work.
//   - Sound does, but CD-audio doesn't without some further hacks.

#include <stdlib.h>
#include <string.h>


void *x_builtin_new(unsigned int size)
{
	return malloc(size);
}

void x_builtin_delete(void *ptr)
{
	return free(ptr);
}


void *x_builtin_vec_new(unsigned int size)
{
	return malloc(size);
}

void x_builtin_vec_delete(void *ptr)
{
	return free(ptr);
}

/* Placement new */
void *x_nw__FUiPv(int size, void *p)
{
	return p;
}


/* CivCTP overlaps all the time in memcpy, strcpy, and strncpy. */
void *memcpx(void *dest, const void *src, size_t n)
{
	return memmove(dest, src, n);
}

char *strcpx(char *dest, const char *src)
{
	size_t len = strlen(src);
	char *ret = memmove(dest, src, len);
	dest[len] = '\0';
	return ret;
}


char *strncpx(char *dest, const char *src, size_t n)
{
	/* Taken from 'man strncpy' */
	size_t i;

	for (i = 0; i < n && src[i] != '\0'; i++)
		dest[i] = src[i];
	for ( ; i < n; i++)
		dest[i] = '\0';

	return dest;
}