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/*
* A helper routine to copy the strings between differing structures.
*/
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include "mph.h"
#define MAX_OFFSETS 10
#define str_at(p, n) (*(char**)(((char*)p)+n))
char* MPH_INTERNAL
_mph_copy_structure_strings (
void *to, const size_t *to_offsets,
const void *from, const size_t *from_offsets,
size_t num_strings)
{
int i;
size_t buflen;
int len[MAX_OFFSETS];
char *buf, *cur = NULL;
g_assert (num_strings < MAX_OFFSETS);
for (i = 0; i < num_strings; ++i) {
str_at (to, to_offsets[i]) = NULL;
}
buflen = num_strings;
for (i = 0; i < num_strings; ++i) {
len[i] = strlen (str_at(from, from_offsets[i]));
if (len[i] < INT_MAX - buflen)
buflen += len[i];
else
len[i] = -1;
}
cur = buf = malloc (buflen);
if (buf == NULL) {
return NULL;
}
for (i = 0; i < num_strings; ++i) {
if (len[i] > 0) {
str_at (to, to_offsets[i]) =
strcpy (cur, str_at (from, from_offsets[i]));
cur += (len[i] +1);
}
}
return buf;
}
#ifdef TEST
#include <stdio.h>
struct foo {
char *a;
int b;
char *c;
};
struct bar {
int b;
char *a;
double d;
char *c;
};
int
main ()
{
/* test copying foo to bar */
struct foo f = {"hello", 42, "world"};
struct bar b;
size_t foo_offsets[] = {offsetof(struct foo, a), offsetof(struct foo, c)};
size_t bar_offsets[] = {offsetof(struct bar, a), offsetof(struct bar, c)};
char *buf;
buf = _mph_copy_structure_strings (&b, bar_offsets,
&f, foo_offsets, 2);
printf ("b.a=%s\n", b.a);
printf ("b.c=%s\n", b.c);
return 0;
}
#endif
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