gcc/testsuite/gcc.dg/tree-ssa/builtin-printf-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 printf 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 typedef unsigned char UChar;
  27
  28 void sink (void*, ...);
  29
  30 int dummy_printf (const char*, ...);
  31
  32 const char chr_no_nul = 'a';
  33 const char arr_no_nul[] = { 'a', 'b' };
  34
  35
  36 /* Helper to expand function to either __builtin_f or dummy_f to
  37    make debugging GCC easy.  */
  38 #define T(...)                                                  \
  39   (((!LINE || LINE == __LINE__)                                 \
  40     ? __builtin_printf : dummy_printf) (__VA_ARGS__))
  41
  42 /* Exercise the "%c" directive with constant arguments.  */
  43
  44 void test_printf_c_const (int width)
  45 {
  46   /* Verify that a warning is issued for exceeding INT_MAX bytes and
  47      not otherwise.  */
  48   T ("%*c",  INT_MAX - 1, '1');
  49   T ("%*c",  INT_MAX,     '1');
  50   T ("X%*c", INT_MAX - 1, '1');
  51   T ("X%*c", INT_MAX,     '1');   /* { dg-warning "directive output of \[0-9\]+ bytes causes result to exceed .INT_MAX." } */
  52
  53   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." } */
  54
  55   T ("%*cX", INT_MAX - 2, '1');
  56   T ("%*cX", INT_MAX - 1, '1');
  57   T ("%*cX", INT_MAX,     '1');   /* { dg-warning "output of \[0-9\]+ bytes causes result to exceed .INT_MAX." } */
  58
  59   if (width < INT_MAX - 1)
  60     width = INT_MAX - 1;
  61   T ("%*cX", width, '1');
  62   T ("%*cXY", width, '1');        /* { dg-warning ".XY. directive output of 2 bytes causes result to exceed .INT_MAX." } */
  63
  64   /* Also exercise a non-constant format string.  The warning points
  65      to the line where the format is declared (see bug 87773) so avoid
  66      triggering that bug here.  */
  67   const char *fmt = "%*cXYZ";  T (fmt, width, '1');            /* { dg-warning ".XYZ. directive output of 3 bytes causes result to exceed .INT_MAX." } */
  68 }
  69
  70
  71 /* Exercise the "%s" directive with constant arguments.  */
  72
  73 void test_printf_s_const (int width)
  74 {
  75   const char *nulptr = 0;
  76
  77   T ("%s", nulptr);               /* { dg-warning "\\\[-Wformat|-Wnonnull]" } */
  78   T ("%.0s", nulptr);             /* { dg-warning ".%.0s. directive argument is null" } */
  79
  80   /* Verify no warning is issued for unreachable code.  */
  81   if (nulptr)
  82     T ("%s", nulptr);
  83
  84   T ("%s", &chr_no_nul);          /* { dg-warning ".%s. directive argument is not a nul-terminated string" "pr87756" { xfail *-*-* } } */
  85   T ("%s", arr_no_nul);           /* { dg-warning ".%s. directive argument is not a nul-terminated string" } */
  86
  87   /* Verify that output in excess of INT_MAX bytes is diagnosed even
  88      when the size of the destination object is unknown.  */
  89   T ("%*s",  INT_MAX - 1, "");
  90   T ("%*s",  INT_MAX,     "");
  91   T ("X%*s", INT_MAX,     "");    /* { dg-warning "directive output of \[0-9\]+ bytes causes result to exceed .INT_MAX." } */
  92
  93   if (width < INT_MAX - 1)
  94     width = INT_MAX - 1;
  95   T ("%*sX", width, "1");
  96   T ("%*sXY", width, "1");        /* { dg-warning ".XY. directive output of 2 bytes causes result to exceed .INT_MAX." } */
  97 }
  98
  99
 100 const wchar_t wchr_no_nul = L'a';
 101 const wchar_t warr_no_nul[] = { L'a', L'b' };
 102
 103 /* Exercise the "%s" directive with constant arguments.  */
 104
 105 void test_printf_ls_const (int width)
 106 {
 107   const wchar_t *nulptr = 0;
 108
 109   T ("%ls", nulptr);              /* { dg-warning ".%ls. directive argument is null" } */
 110   T ("%.0ls", nulptr);            /* { dg-warning ".%.0ls. directive argument is null" } */
 111
 112   /* Verify no warning is issued for unreachable code.  */
 113   if (nulptr)
 114     T ("%ls", nulptr);
 115
 116   T ("%ls", &wchr_no_nul);        /* { dg-warning ".%ls. directive argument is not a nul-terminated string" "pr87756" { xfail *-*-* } } */
 117   T ("%ls", warr_no_nul);         /* { dg-warning ".%ls. directive argument is not a nul-terminated string" "pr87756" { xfail *-*-* } } */
 118
 119   /* Verify that output in excess of INT_MAX bytes is diagnosed even
 120      when the size of the destination object is unknown.  */
 121   T ("%*ls",  INT_MAX - 1, L"");
 122   T ("%*ls",  INT_MAX,     L"");
 123   T ("X%*ls", INT_MAX,     L"");  /* { dg-warning "directive output of \[0-9\]+ bytes causes result to exceed .INT_MAX." } */
 124
 125   if (width < INT_MAX - 1)
 126     width = INT_MAX - 1;
 127   T ("%*lsX", width, L"1");
 128   T ("%*lsXY", width, L"1");      /* { dg-warning ".XY. directive output of 2 bytes causes result to exceed .INT_MAX." } */
 129 }