gcc/testsuite/c-c++-common/analyzer/out-of-bounds-2.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3 #include <stdio.h>
   4 #include <stdint.h>
   5
   6 /* Wanalyzer-out-of-bounds tests for buffer over-reads.  */
   7
   8 /* Avoid folding of memcpy.  */
   9 typedef void * (*memcpy_t) (void *dst, const void *src, size_t n);
  10
  11 static memcpy_t __attribute__((noinline))
  12 get_memcpy (void)
  13 {
  14   return memcpy;
  15 }
  16
  17
  18 void test1 (void)
  19 {
  20   int id_sequence[3];
  21   memset (id_sequence, 0, 3 * sizeof(int));
  22   printf ("%i", id_sequence[3]); /* { dg-line test1 } */
  23
  24   /* { dg-warning "stack-based buffer over-read" "warning" { target *-*-* } test1 } */
  25   /* { dg-message "read of 4 bytes from after the end of 'id_sequence'" "num bad bytes note" { target *-*-* } test1 } */
  26   /* { dg-message "valid subscripts for 'id_sequence' are '\\\[0\\\]' to '\\\[2\\\]'" "valid subscript note" { target *-*-* } test1 } */
  27 }
  28
  29 void test2 (void)
  30 {
  31   int n = 4;
  32   int arr[n];
  33   memset (arr, 0, n * sizeof (int));
  34
  35   int sum = 0;
  36   for (int i = n - 1; i >= 0; i--)
  37     sum += arr[i];
  38 }
  39
  40 void test3 (void)
  41 {
  42   int n = 4;
  43   int arr[4];
  44   memset (arr, 0, n * sizeof (int));
  45
  46   int sum = 0;
  47   for (int i = n; i > 0; i--)
  48     sum += arr[i]; /* { dg-line test3 } */
  49
  50   /* { dg-warning "stack-based buffer over-read" "warning" { target *-*-* } test3 } */
  51   /* { dg-message "" "note" { target *-*-* } test3 } */
  52 }
  53
  54 void test4 (void)
  55 {
  56   int n = 4;
  57   int *arr = (int *)malloc (n * sizeof (int));
  58   if (!arr)
  59     return;
  60   memset (arr, 0, n * sizeof(int));
  61
  62   int sum = 0;
  63   for (int i = n - 1; i >= 0; i--)
  64     sum += *(arr + i);
  65
  66   free (arr);
  67 }
  68
  69 void test5 (void)
  70 {
  71   int n = 4;
  72   int *arr = (int *)malloc (n * sizeof (int));
  73   if (!arr)
  74     return;
  75   memset (arr, 0, n * sizeof(int));
  76
  77   int sum = 0;
  78   for (int i = n; i > 0; i--)
  79     sum += *(arr + i); /* { dg-line test5 } */
  80
  81   free (arr);
  82   /* { dg-warning "heap-based buffer over-read" "bounds warning" { target *-*-* } test5 } */
  83   /* { dg-message "read of 4 bytes from after the end of the region" "num bad bytes note" { target *-*-* } test5 } */
  84
  85 }