memcheck/tests/varinfo1.c

   1
   2 /* Basic check of variable location identification, in a zero-biased
   3    executable. */
   4
   5 /* Relevant compile flags are:
   6
   7    -Wall -g -I$prefix/include/valgrind
   8
   9    eg -Wall -g -I`pwd`/Inst/include/valgrind
  10 */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <assert.h>
  15 #include "memcheck/memcheck.h"
  16
  17 /* Cause memcheck to complain about the address "a" and so to print
  18    its best guess as to what "a" actually is.  a must be
  19    addressible. */
  20
  21 void croak ( void* aV )
  22 {
  23   char* a = (char*)aV;
  24   char* undefp = malloc(1);
  25   char saved = *a;
  26   assert(undefp);
  27   *a = *undefp;
  28   (void) VALGRIND_CHECK_MEM_IS_DEFINED(a, 1);
  29   *a = saved;
  30   free(undefp);
  31 }
  32
  33 #include <stdio.h>
  34
  35 int global_u1;
  36
  37 int global_i1 = 17;
  38
  39 char global_u2[10];
  40
  41 char global_i2[10] = { 1,2,3,4,5,6,7,8,9,10 };
  42
  43
  44 int main ( void )
  45 {
  46   int local;
  47   char* onheap = malloc(3);
  48   assert(onheap);
  49   croak(onheap+1);
  50   free(onheap);
  51
  52   croak( &global_u1 );
  53   croak( &global_i1 );
  54   croak( &global_u2[3] );
  55   croak( &global_i2[7] );
  56   croak( &local );
  57   return 0;
  58 }