gcc/testsuite/c-c++-common/analyzer/pr101962.c

   1 #include "../../gcc.dg/analyzer/analyzer-decls.h"
   2
   3
   4 /* Verify that the analyzer makes the simplifying assumption that we don't
   5    hit NULL when incrementing pointers to non-NULL memory regions.  */
   6
   7 static int * __attribute__((noinline))
   8 maybe_inc_int_ptr (int *ptr)
   9 {
  10   if (!ptr)
  11     return NULL;
  12   return ++ptr;
  13 }
  14
  15 int
  16 test_1 (void)
  17 {
  18   int stack;
  19   int *a = &stack;
  20   a = maybe_inc_int_ptr (a);
  21   a = maybe_inc_int_ptr (a);
  22   __analyzer_eval (a == NULL); /* { dg-warning "FALSE" } */
  23   __analyzer_eval (a != NULL); /* { dg-warning "TRUE" } */
  24   return *a; /* { dg-line test_1 } */
  25
  26   /* { dg-warning "stack-based buffer over-read" "warning" { target *-*-* } test_1 } */
  27 }
  28
  29 static const char * __attribute__((noinline))
  30 maybe_inc_char_ptr (const char *ptr)
  31 {
  32   if (!ptr)
  33     return NULL;
  34   return ++ptr;
  35 }
  36
  37 void
  38 test_s (void)
  39 {
  40   const char *msg = "hello world";
  41   const char *a = msg;
  42   __analyzer_eval (*a == 'h'); /* { dg-warning "TRUE" } */
  43   a = maybe_inc_char_ptr (a);
  44   __analyzer_eval (*a == 'e'); /* { dg-warning "TRUE" } */
  45   a = maybe_inc_char_ptr (a);
  46   __analyzer_eval (*a == 'l'); /* { dg-warning "TRUE" } */
  47   a = maybe_inc_char_ptr (a);
  48   __analyzer_eval (*a == 'l'); /* { dg-warning "TRUE" } */
  49   a = maybe_inc_char_ptr (a);
  50   __analyzer_eval (*a == 'o'); /* { dg-warning "TRUE" } */
  51 }