memcheck/tests/err_disable1.c

   1
   2 /* Test simple use of the disable/enable macros. */
   3
   4 #include <stdlib.h>
   5 #include <stdio.h>
   6
   7 #include "../include/valgrind.h"
   8
   9 char* block = NULL;
  10
  11 __attribute__((noinline)) void usechar ( char c )
  12 {
  13    // Spook gcc into believing mysterious bad things are
  14    // happening behind its back, and that 'c' is definitely
  15    // used in some (unknown) way.
  16    __asm__ __volatile__("" : : "r"(c) : "memory","cc");
  17 }
  18
  19 __attribute__((noinline)) void err ( void )
  20 {
  21    usechar( block[5] );
  22 }
  23
  24 int main ( void )
  25 {
  26   block = malloc(10);
  27   free(block);
  28
  29   fprintf(stderr, "\n--------- SIMPLE TEST ---------\n\n");
  30   fprintf(stderr, "\n--------- enabled (expect 1) ---------\n\n");
  31
  32   err();
  33
  34   fprintf(stderr, "\n--------- disabled (expect 0) ---------\n\n");
  35   VALGRIND_DISABLE_ERROR_REPORTING;
  36
  37   err();
  38
  39   fprintf(stderr, "\n--------- re-enabled (expect 1) ---------\n\n");
  40   VALGRIND_ENABLE_ERROR_REPORTING;
  41
  42   err();
  43
  44
  45
  46   fprintf(stderr, "\n--------- MULTI-LEVEL TEST (expect 2) ---------\n\n");
  47
  48   // 4 times
  49   VALGRIND_DISABLE_ERROR_REPORTING;
  50   VALGRIND_DISABLE_ERROR_REPORTING;
  51   VALGRIND_DISABLE_ERROR_REPORTING;
  52   VALGRIND_DISABLE_ERROR_REPORTING; // lev = 4
  53
  54   // now gradually undo them until an error appears
  55   err();  // hidden
  56
  57   VALGRIND_ENABLE_ERROR_REPORTING; // lev = 3
  58   err();  // hidden
  59
  60   VALGRIND_ENABLE_ERROR_REPORTING; // lev = 2
  61   err();  // hidden
  62
  63   VALGRIND_ENABLE_ERROR_REPORTING; // lev = 1
  64   err();  // hidden
  65
  66   VALGRIND_ENABLE_ERROR_REPORTING; // lev = 0
  67   err();  // visible
  68
  69   VALGRIND_ENABLE_ERROR_REPORTING; // lev = 0 (won't go down further)
  70   err();  // visible
  71
  72   fprintf(stderr, "\n--------- MULTI-LEVEL TEST end ---------\n\n");
  73
  74   return 0;
  75 }