1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
/* A small demo of providing descriptions of structured types in error
messages. */
/* Relevant compile flags are:
-Wall -g -I$prefix/include/valgrind
eg -Wall -g -I`pwd`/Inst/include/valgrind
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "memcheck/memcheck.h"
/* Cause memcheck to complain about the address "a" and so to print
its best guess as to what "a" actually is. a must be
addressible. */
void croak ( void* aV )
{
char* a = (char*)aV;
char* undefp = malloc(1);
char saved = *a;
assert(undefp);
*a = *undefp;
(void) VALGRIND_CHECK_MEM_IS_DEFINED(a, 1);
*a = saved;
free(undefp);
}
#include <stdio.h>
#include <string.h>
typedef struct { short c1; char* c2[3]; } XX;
typedef
struct _str { int bing; int bong; XX xyzzy[77]; }
Str;
__attribute__((noinline))
int blah ( int x, int y )
{
Str a[10];
memset(a, 0, sizeof(a));
croak(1 + (char*)(&a[3].xyzzy[x*y].c1));
croak( (char*)(&a[5].bong) );
croak( 1 + (char*)(&a[3].xyzzy[x*y].c2[2]) );
memset(a, 0, sizeof(a));
return a[3].xyzzy[x*y].c1;
}
int main ( void )
{
printf("answer is %d\n", blah(3,7) );
return 0;
}
|
