gcc/testsuite/gcc.dg/tree-ssa/builtin-fprintf-warn-1.c

   1 /* PR middle-end/87041 - -Wformat "reading through null pointer" on
   2    unreachable code
   3    Test to verify that the applicable subset of -Wformat-overflow warnings
   4    are issued for the fprintf function.
   5    { dg-do compile }
   6    { dg-options "-O -Wformat -Wformat-overflow=1 -ftrack-macro-expansion=0" }
   7    { dg-require-effective-target int32plus } */
   8
   9 /* When debugging, define LINE to the line number of the test case to exercise
  10    and avoid exercising any of the others.  The buffer and objsize macros
  11    below make use of LINE to avoid warnings for other lines.  */
  12 #ifndef LINE
  13 # define LINE 0
  14 #endif
  15
  16 #define INT_MAX __INT_MAX__
  17
  18 typedef __SIZE_TYPE__ size_t;
  19
  20 #if !__cplusplus
  21 typedef __WCHAR_TYPE__ wchar_t;
  22 #endif
  23
  24 typedef __WINT_TYPE__ wint_t;
  25
  26 void sink (void*, ...);
  27
  28 /* Declare as void* to work around bug 87775.  */
  29 typedef void FILE;
  30
  31 int dummy_fprintf (FILE*, const char*, ...);
  32
  33 FILE *fp;
  34
  35 const char chr_no_nul = 'a';
  36 const char arr_no_nul[] = { 'a', 'b' };
  37
  38
  39 /* Helper to expand function to either __builtin_f or dummy_f to
  40    make debugging GCC easy.  */
  41 #define T(...)                                                  \
  42   (((!LINE || LINE == __LINE__)                                 \
  43     ? __builtin_fprintf : dummy_fprintf) (fp, __VA_ARGS__))
  44
  45 /* Exercise the "%c" directive with constant arguments.  */
  46
  47 void test_fprintf_c_const (int width)
  48 {
  49   /* Verify that a warning is issued for exceeding INT_MAX bytes and
  50      not otherwise.  */
  51   T ("%*c",  INT_MAX - 1, '1');
  52   T ("%*c",  INT_MAX,     '1');
  53   T ("X%*c", INT_MAX - 1, '1');
  54   T ("X%*c", INT_MAX,     '1');   /* { dg-warning "directive output of \[0-9\]+ bytes causes result to exceed .INT_MAX." } */
  55
  56   T ("%*c%*c", INT_MAX - 1, '1', INT_MAX - 1, '2'); /* { dg-warning "directive output of \[0-9\]+ bytes causes result to exceed .INT_MAX." } */
  57
  58   T ("%*cX", INT_MAX - 2, '1');
  59   T ("%*cX", INT_MAX - 1, '1');
  60   T ("%*cX", INT_MAX,     '1');   /* { dg-warning "output of \[0-9\]+ bytes causes result to exceed .INT_MAX." } */
  61
  62   if (width < INT_MAX - 1)
  63     width = INT_MAX - 1;
  64   T ("%*cX", width, '1');
  65   T ("%*cXY", width, '1');        /* { dg-warning ".XY. directive output of 2 bytes causes result to exceed .INT_MAX." } */
  66
  67   /* Also exercise a non-constant format string.  The warning points
  68      to the line where the format is declared (see bug 87773) so avoid
  69      triggering that bug here.  */
  70   const char *fmt = "%*cXYZ";  T (fmt, width, '1');            /* { dg-warning ".XYZ. directive output of 3 bytes causes result to exceed .INT_MAX." } */
  71 }
  72
  73
  74 /* Exercise the "%s" directive with constant arguments.  */
  75
  76 void test_fprintf_s_const (int width)
  77 {
  78   const char *nulptr = 0;
  79
  80   T ("%s", nulptr);               /* { dg-warning "\\\[-Wformat|-Wnonnull" } */
  81   T ("%.0s", nulptr);             /* { dg-warning ".%.0s. directive argument is null" } */
  82
  83   /* Verify no warning is issued for unreachable code.  */
  84   if (nulptr)
  85     T ("%s", nulptr);
  86
  87   T ("%s", &chr_no_nul);          /* { dg-warning ".%s. directive argument is not a nul-terminated string|argument missing terminating nul" } */
  88   T ("%s", arr_no_nul);           /* { dg-warning ".%s. directive argument is not a nul-terminated string|argument missing terminating nul" } */
  89
  90   /* Verify that output in excess of INT_MAX bytes is diagnosed even
  91      when the size of the destination object is unknown.  */
  92   T ("%*s",  INT_MAX - 1, "");
  93   T ("%*s",  INT_MAX,     "");
  94   T ("X%*s", INT_MAX,     "");    /* { dg-warning "directive output of \[0-9\]+ bytes causes result to exceed .INT_MAX." } */
  95
  96   if (width < INT_MAX - 1)
  97     width = INT_MAX - 1;
  98   T ("%*sX", width, "1");
  99   T ("%*sXY", width, "1");        /* { dg-warning ".XY. directive output of 2 bytes causes result to exceed .INT_MAX." } */
 100 }
 101
 102
 103 const wchar_t wchr_no_nul = L'a';
 104 const wchar_t warr_no_nul[] = { L'a', L'b' };
 105
 106 /* Exercise the "%s" directive with constant arguments.  */
 107
 108 void test_fprintf_ls_const (int width)
 109 {
 110   const wchar_t *nulptr = 0;
 111
 112   T ("%ls", nulptr);              /* { dg-warning ".%ls. directive argument is null" } */
 113   T ("%.0ls", nulptr);            /* { dg-warning ".%.0ls. directive argument is null" } */
 114
 115   /* Verify no warning is issued for unreachable code.  */
 116   if (nulptr)
 117     T ("%ls", nulptr);
 118
 119   T ("%ls", &wchr_no_nul);        /* { dg-warning ".%ls. directive argument is not a nul-terminated string" } */
 120   T ("%ls", warr_no_nul);         /* { dg-warning ".%ls. directive argument is not a nul-terminated string" "pr88226" { xfail *-*-* } } */
 121
 122   /* Verify that output in excess of INT_MAX bytes is diagnosed even
 123      when the size of the destination object is unknown.  */
 124   T ("%*ls",  INT_MAX - 1, L"");
 125   T ("%*ls",  INT_MAX,     L"");
 126   T ("X%*ls", INT_MAX,     L"");  /* { dg-warning "directive output of \[0-9\]+ bytes causes result to exceed .INT_MAX." } */
 127
 128   if (width < INT_MAX - 1)
 129     width = INT_MAX - 1;
 130   T ("%*lsX", width, L"1");
 131   T ("%*lsXY", width, L"1");      /* { dg-warning ".XY. directive output of 2 bytes causes result to exceed .INT_MAX." } */
 132 }