gcc/testsuite/gcc.dg/tree-ssa/builtin-snprintf-warn-3.c

   1 /* PR middle-end/79448 - unhelpful -Wformat-truncation=2 warning
   2    { dg-do compile }
   3    { dg-options "-O2 -Wformat -Wformat-truncation=2 -ftrack-macro-expansion=0" }
   4    { dg-require-effective-target ptr32plus } */
   5
   6 typedef __SIZE_TYPE__  size_t;
   7 typedef __WCHAR_TYPE__ wchar_t;
   8
   9 #define INT_MAX __INT_MAX__
  10 #define INT_MIN (-INT_MAX - 1)
  11
  12 /* When debugging, define LINE to the line number of the test case to exercise
  13    and avoid exercising any of the others.  The buffer and objsize macros
  14    below make use of LINE to avoid warnings for other lines.  */
  15 #ifndef LINE
  16 # define LINE 0
  17 #endif
  18
  19 extern int int_value (void);
  20 extern size_t size_value (void);
  21
  22 int int_range (int min, int max)
  23 {
  24   int n = int_value ();
  25   return n < min || max < n ? min : n;
  26 }
  27
  28 void sink (int, char*, char*);
  29
  30 int dummy_snprintf (char*, size_t, const char*, ...);
  31
  32 char fixed_buffer [256];
  33 extern char *unknown_buffer;
  34 extern size_t unknown_size;
  35
  36 /* Helper to expand function to either __builtin_f or dummy_f to
  37    make debugging GCC easy.  */
  38 #define FUNC(f)                                                 \
  39   ((!LINE || LINE == __LINE__) ? __builtin_ ## f : dummy_ ## f)
  40
  41 /* Helper test macro.  */
  42 #define T(size, ...)                                    \
  43   do {                                                  \
  44     size_t n = size < 0 ? unknown_size : size;          \
  45     char *buf = size < 0 ? unknown_buffer               \
  46       : n < sizeof fixed_buffer                         \
  47       ? fixed_buffer + sizeof fixed_buffer - size       \
  48       : unknown_buffer;                                 \
  49     FUNC (snprintf) (buf, n, __VA_ARGS__);              \
  50     sink (0, fixed_buffer, unknown_buffer);             \
  51   } while (0)
  52
  53 /* Return a value in the range [MIN, MAX].  */
  54 #define IR(min, max)  int_range (min, max)
  55
  56 struct Arrays
  57 {
  58   char a1[1];
  59   char a4k[4096];
  60   char a4kp1[4097];
  61 #if INT_MAX < LONG_MAX
  62   char amax[INT_MAX];
  63 #else
  64   char amax[32767];
  65 #endif
  66   char ax[];
  67 };
  68
  69 void test_string_unchecked (const char *s, const struct Arrays *ar)
  70 {
  71   /* Verify there is no warning with strings of unknown length.  */
  72   T (-1, "%-s", s);
  73   T (-1, "%-s", ar->ax);
  74
  75   T (-1, "%s%s", s, s);
  76   T (-1, "%s%s", "", s);
  77   T (-1, "%s%s", s, "1");
  78   T (-1, "%s%s", "1", s);
  79
  80   /* Verify there is no warning with strings of length that cannot
  81      exceed 4k (because of the array size).  */
  82   T (-1, "%-s", ar->a1);
  83   T (-1, "%-s", ar->a4k);
  84
  85   /* Verify there's no "exceeds minimum required size of 4095" warning
  86      with multiple %s directives and a combination of strings of unknown
  87      (and potentially unbounded) length and strings whose length is
  88      bounded by the size of the arrays they are stored in.  */
  89   T (-1, "%s%s", s, ar->a4k);
  90   T (-1, "%s%s", ar->a4k, s);
  91   T (-1, "%s%s", ar->a4k, ar->a4k);
  92   T (-1, "%s%s", ar->a4k, "123");
  93   T (-1, "%s%s", "123", ar->a4k);
  94   T (-1, "%s%s", ar->ax, ar->a4k);
  95   T (-1, "%s%s", ar->a4k, ar->ax);
  96
  97   /* Verify that an array that fits a string longer than 4095 bytes
  98      does trigger a warning.  */
  99   T (-1, "%-s", ar->a4kp1);   /* { dg-warning "directive output between 0 and 4096 bytes may exceed minimum required size of 4095" } */
 100
 101   /* Also verify that a %s directive with width greater than 4095
 102      triggers a warning even if the argument is not longer than 4k.  */
 103   T (-1, "%*s", 4096, ar->a4k);   /* { dg-warning "directive output of 4096 bytes exceeds minimum required size of 4095" } */
 104
 105   /* Verify that precision constrains the putput and suppresses the 4k
 106      warning.  */
 107   T (-1, "%.*s", 4095, ar->a4kp1);
 108
 109   T (-1, "%s %s", s, "");
 110   T (-1, "%s %s", "", s);
 111   T (-1, "%s %s", s, "1");
 112   T (-1, "%s %s", "1", s);
 113
 114   T (-1, "%s%s%s", s, "1", s);
 115   T (-1, "%s%s%s", "1", s, "1");
 116   T (-1, "%s%s%s", s, s, s);
 117   T (-1, "%*s%*s%*s", 4093, s, 4094, s, 4095, s);
 118   T (-1, "%s %s %s", s, s, s);
 119   T (-1, "%s %s %s", ar->a4k, ar->a4k, ar->a4k);
 120   T (-1, "%s %s %s", ar->ax, ar->ax, ar->ax);
 121
 122   /* Verify that an array of INT_MAX elements doesn't trigger the INT_MAX
 123      warning (LP64 only).  */
 124   T (-1, "%-s", ar->amax);   /* { dg-warning "directive output between 0 and \[0-9\]+ bytes may exceed minimum required size of 4095" } */
 125 }
 126
 127 #undef T
 128 /* Helper test macro.  */
 129 #define T(size, ...)                                    \
 130   do {                                                  \
 131     size_t n = size < 0 ? unknown_size : size;          \
 132     char *buf = size < 0 ? unknown_buffer               \
 133       : n < sizeof fixed_buffer                         \
 134       ? fixed_buffer + sizeof fixed_buffer - size       \
 135       : unknown_buffer;                                 \
 136     int r = FUNC (snprintf) (buf, n, __VA_ARGS__);      \
 137     sink (r, fixed_buffer, unknown_buffer);             \
 138   } while (0)
 139
 140 void test_string_checked (const char *s, const struct Arrays *ar)
 141 {
 142   /* Verify there is no warning with strings of unknown length.  */
 143   T (-1, "%-s", s);
 144   T (-1, "%-s", ar->ax);
 145
 146   T (-1, "%s%s", s, s);
 147   T (-1, "%s%s", "", s);
 148   T (-1, "%s%s", s, "1");
 149   T (-1, "%s%s", "1", s);
 150
 151   /* Verify there is no warning with strings of length that cannot
 152      exceed 4k (because of the array size).  */
 153   T (-1, "%-s", ar->a1);
 154   T (-1, "%-s", ar->a4k);
 155
 156   /* Verify there's no "exceeds minimum required size of 4095" warning
 157      with multiple %s directives and a combination of strings of unknown
 158      (and potentially unbounded) length and strings whose length is
 159      bounded by the size of the arrays they are stored in.  */
 160   T (-1, "%s%s", s, ar->a4k);
 161   T (-1, "%s%s", ar->a4k, s);
 162   T (-1, "%s%s", ar->a4k, ar->a4k);
 163   T (-1, "%s%s", ar->a4k, "123");
 164   T (-1, "%s%s", "123", ar->a4k);
 165   T (-1, "%s%s", ar->ax, ar->a4k);
 166   T (-1, "%s%s", ar->a4k, ar->ax);
 167
 168   /* Verify that an array that fits a string longer than 4095 bytes
 169      does trigger a warning.  */
 170   T (-1, "%-s", ar->a4kp1);   /* { dg-warning "directive output between 0 and 4096 bytes may exceed minimum required size of 4095" } */
 171
 172   /* Also verify that a %s directive with width greater than 4095
 173      triggers a warning even if the argument is not longer than 4k.  */
 174   T (-1, "%*s", 4096, ar->a4k);   /* { dg-warning "directive output of 4096 bytes exceeds minimum required size of 4095" } */
 175
 176   /* Verify that precision constrains the putput and suppresses the 4k
 177      warning.  */
 178   T (-1, "%.*s", 4095, ar->a4kp1);
 179
 180   T (-1, "%s %s", s, "");
 181   T (-1, "%s %s", "", s);
 182   T (-1, "%s %s", s, "1");
 183   T (-1, "%s %s", "1", s);
 184
 185   T (-1, "%s%s%s", s, "1", s);
 186   T (-1, "%s%s%s", "1", s, "1");
 187   T (-1, "%s%s%s", s, s, s);
 188   T (-1, "%*s%*s%*s", 4093, s, 4094, s, 4095, s);
 189   T (-1, "%s %s %s", s, s, s);
 190   T (-1, "%s %s %s", ar->a4k, ar->a4k, ar->a4k);
 191   T (-1, "%s %s %s", ar->ax, ar->ax, ar->ax);
 192
 193   T (-1, "%-s", ar->amax);   /* { dg-warning "directive output between 0 and \[0-9\]+ bytes may exceed minimum required size of 4095" } */
 194 }