gcc/testsuite/gcc.dg/warn-strnlen-no-nul-2.c

   1 /* Verify that calls to strnlen with an unterminated array and
   2    an excessive non-constant bound are diagnosed.
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall -ftrack-macro-expansion=0" } */
   5
   6 #include "range.h"
   7
   8 extern size_t strnlen (const char*, size_t);
   9
  10 const char a[5] = "12345";   /* { dg-message "declared here" } */
  11 enum { asz = sizeof a };
  12
  13 int v0 = 0;
  14 int v1 = 1;
  15
  16 void sink (int, ...);
  17
  18 #define CONCAT(a, b)   a ## b
  19 #define CAT(a, b)      CONCAT(a, b)
  20
  21 #define T(str, n)                                       \
  22   __attribute__ ((noipa))                               \
  23   void CAT (test_, __LINE__) (void) {                   \
  24     int i0 = 0, i1 = i0 + 1, i2 = i1 + 1, i3 = i2 + 1;  \
  25     sink (strnlen (str, n), i0, i1, i2, i3);            \
  26   } typedef void dummy_type
  27
  28
  29 T (a, UR (asz, -1));
  30 T (a, UR (asz - 1, -1));
  31 T (a, UR (asz - 2, -1));
  32 T (a, UR (asz - 5, -1));
  33 T (&a[0], UR (asz, -1));
  34 T (&a[0] + 1, UR (asz, asz + 1)); /* { dg-warning "specified bound \\\[5, 6] exceeds the size 4 of unterminated array" } */
  35 T (&a[1], UR (asz, 6));           /* { dg-warning "specified bound \\\[5, 6] exceeds the size 4 of unterminated array" } */
  36 T (&a[1], UR (asz - 1, 7));
  37 T (&a[v0], UR (asz, 8));          /* { dg-warning "specified bound \\\[5, 8] may exceed the size of at most 5 of unterminated array" } */
  38 T (&a[v0] + 1, UR (asz, 9));      /* { dg-warning "specified bound \\\[5, 9] may exceed the size of at most 5 of unterminated array" } */
  39
  40 T (a, UR (asz + 1, asz + 2));     /* { dg-warning "specified bound \\\[6, 7] exceeds the size 5 " } */
  41 T (&a[0], UR (asz + 1, 10));      /* { dg-warning "unterminated" } */
  42 T (&a[0] + 1, UR (asz - 1, 11));
  43 T (&a[0] + 1, UR (asz + 1, 12));  /* { dg-warning "unterminated" } */
  44 T (&a[1], UR (asz + 1, 13));      /* { dg-warning "unterminated" } */
  45 T (&a[v0], UR (asz + 1, 14));     /* { dg-warning "unterminated" } */
  46 T (&a[v0] + 1, UR (asz + 1, 15)); /* { dg-warning "unterminated" } */
  47
  48 T (&a[v0] + 1, UR (DIFF_MAX, SIZE_MAX)); /* { dg-warning "unterminated" } */
  49
  50 T (&a[v0] + 1, UR (DIFF_MAX + (size_t)1, SIZE_MAX)); /* { dg-warning "specified bound \\\[\[0-9\]+, \[0-9\]+] exceeds maximum object size " } */
  51
  52
  53 const char c[4] = "1234";
  54
  55 void test (int n0)
  56 {
  57   char a[] = "123";
  58
  59   if (n0 < 4)
  60     n0 = 4;
  61   int n1 = __builtin_strlen (a);
  62
  63   int n = n0 < n1 ? n1 : n0;
  64
  65   /* N is at least 4 and c[4] is out-of-bounds.  This could trigger
  66      either -Warray-bounds or -Wstringop-overread.  -Warray-bounds
  67      only diagnoses past-the-end accesses by modifying functions
  68      (in gimple-ssa-warn-restrict.c) and even for those, either
  69      -Wstringop-overflow or -Wstringop-overread would be more
  70      appropriate.  */
  71   sink (strnlen (c + n, n + 1));    /* { dg-warning "specified bound \\\[5, \[0-9\]+] exceeds the size of at most 4 of unterminated array" } */
  72 }