memcheck/tests/wrap4.c

   1
   2 #include <stdio.h>
   3 #include "valgrind.h"
   4
   5 /* Check that it's safe to call a wrapped function from some other
   6    function's wrapper.  Note that because the wrapper for fact1
   7    actually interferes with the computation of the result, this
   8    program produces a different answer when run on V (162) from
   9    natively (120).
  10 */
  11
  12 static int fact1 ( int n );
  13 static int fact2 ( int n );
  14
  15 /* This is needed to stop gcc4 turning 'fact' into a loop */
  16 __attribute__((noinline))
  17 int mul ( int x, int y ) { return x * y; }
  18
  19 int fact1 ( int n )
  20 {
  21    if (n == 0) return 1; else return mul(n, fact2(n-1));
  22 }
  23 int fact2 ( int n )
  24 {
  25    if (n == 0) return 1; else return mul(n, fact1(n-1));
  26 }
  27
  28
  29 int I_WRAP_SONAME_FNNAME_ZU(NONE,fact1) ( int n )
  30 {
  31    int    r;
  32    OrigFn fn;
  33    VALGRIND_GET_ORIG_FN(fn);
  34    printf("in wrapper1-pre:  fact(%d)\n", n);
  35    CALL_FN_W_W(r, fn, n);
  36    printf("in wrapper1-post: fact(%d) = %d\n", n, r);
  37    if (n >= 3) r += fact2(2);
  38    return r;
  39 }
  40
  41 int I_WRAP_SONAME_FNNAME_ZU(NONE,fact2) ( int n )
  42 {
  43    int    r;
  44    OrigFn fn;
  45    VALGRIND_GET_ORIG_FN(fn);
  46    printf("in wrapper2-pre:  fact(%d)\n", n);
  47    CALL_FN_W_W(r, fn, n);
  48    printf("in wrapper2-post: fact(%d) = %d\n", n, r);
  49    return r;
  50 }
  51
  52 /* --------------- */
  53
  54 int main ( void )
  55 {
  56    int r;
  57    printf("computing fact1(5)\n");
  58    r = fact1(5);
  59    printf("fact1(5) = %d\n", r);
  60    return 0;
  61 }