gcc/testsuite/g++.dg/warn/overflow-warn-3.C

   1 /* Test for diagnostics for constant overflow.  Test with -pedantic.  */
   2 /* Origin: Joseph Myers <joseph@codesourcery.com> */
   3 /* { dg-do compile } */
   4 /* { dg-options "-fpermissive -pedantic" } */
   5
   6 #include <limits.h>
   7
   8 enum e {
   9   E0 = INT_MAX,
  10   /* Unsigned overflow wraps around.  */
  11   E1 = UINT_MAX + 1,
  12   /* Overflow in an unevaluated part of an expression is OK (example
  13      in the standard).  */
  14   E2 = 2 || 1 / 0, /* { dg-bogus "warning: division by zero" "" { xfail *-*-* } 14 } */
  15   E3 = 1 / 0, /* { dg-warning "division by zero" } */
  16   /* { dg-error "enumerator value for 'E3' is not an integer constant|not a constant expression" "enum error" { target *-*-* } 15 } */
  17   /* But as in DR#031, the 1/0 in an evaluated subexpression means the
  18      whole expression violates the constraints.  */
  19   E4 = 0 * (1 / 0), /* { dg-warning "division by zero" } */
  20   /* { dg-error "enumerator value for 'E4' is not an integer constant" "enum error" { xfail *-*-* } 19 } */
  21   E5 = INT_MAX + 1, /* { dg-warning "integer overflow in expression" } */
  22   /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } 21 } */
  23   /* Again, overflow in evaluated subexpression.  */
  24   E6 = 0 * (INT_MAX + 1), /* { dg-warning "integer overflow in expression" } */
  25   /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } 24 } */
  26   /* A cast does not constitute overflow in conversion.  */
  27   E7 = (char) INT_MAX
  28 };
  29
  30 struct s {
  31   int a;
  32   int : 0 * (1 / 0); /* { dg-warning "division by zero" } */
  33   int : 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
  34   /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } 33 } */
  35 };
  36
  37 void
  38 f (void)
  39 {
  40   /* This expression is not required to be a constant expression, so
  41      it should just involve undefined behavior at runtime.  */
  42   int c = INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
  43
  44 }
  45
  46 /* This expression is neither required to be constant.  */
  47 static int sc = INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
  48
  49
  50 // Test for overflow in null pointer constant.
  51 void *n = 0;
  52 /* The first two of these involve overflow, so are not null pointer
  53    constants.  The third has the overflow in an unevaluated
  54    subexpression, so is a null pointer constant.  */
  55 void *p = 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
  56 /* { dg-warning "invalid conversion from 'int' to 'void" "null" { target *-*-* } 55 } */
  57
  58 void *q = 0 * (1 / 0); /* { dg-warning "division by zero" } */
  59 /* { dg-warning "invalid conversion from 'int' to 'void*'" "null" { xfail *-*-* } 58 } */
  60 void *r = (1 ? 0 : INT_MAX+1); /* { dg-bogus "integer overflow in expression" "" { xfail *-*-* } 60 } */
  61
  62 void
  63 g (int i)
  64 {
  65   switch (i)
  66     {
  67     case 0 * (1/0): /* { dg-warning "division by zero" } */
  68       ;
  69     case 1 + 0 * (INT_MAX + 1): /* { dg-warning "integer overflow in expression" } */
  70       /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } 69 } */
  71       ;
  72     }
  73 }
  74
  75 int
  76 h (void)
  77 {
  78   return INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
  79 }
  80
  81 int
  82 h1 (void)
  83 {
  84   return INT_MAX + 1 - INT_MAX; /* { dg-warning "integer overflow in expression" } */
  85 }
  86
  87 void fuc (unsigned char);
  88 void fsc (signed char);
  89
  90 void
  91 h2 (void)
  92 {
  93   fsc (SCHAR_MAX + 1); /* { dg-warning "overflow in implicit constant conversion" } */
  94   fsc (SCHAR_MIN - 1); /* { dg-warning "overflow in implicit constant conversion" } */
  95   fsc (UCHAR_MAX); /* { dg-warning "overflow in implicit constant conversion" } */
  96   fsc (UCHAR_MAX + 1); /* { dg-warning "overflow in implicit constant conversion" } */
  97   fuc (-1);
  98   fuc (UCHAR_MAX + 1); /* { dg-warning "large integer implicitly truncated to unsigned type" } */
  99   fuc (SCHAR_MIN);
 100   fuc (SCHAR_MIN - 1); /* { dg-warning "large integer implicitly truncated to unsigned type" } */
 101   fuc (-UCHAR_MAX); /* { dg-warning "large integer implicitly truncated to unsigned type" } */
 102 }
 103
 104 void fui (unsigned int);
 105 void fsi (signed int);
 106
 107 int si;
 108 unsigned ui;
 109
 110 void
 111 h2i (int x)
 112 {
 113   /* For some reason, we only give certain warnings for implicit
 114      conversions among values of the same precision with -Wconversion,
 115      while we don't give others at all.  */
 116   fsi ((unsigned)INT_MAX + 1);
 117   si = (unsigned)INT_MAX + 1;
 118   si = x ? (unsigned)INT_MAX + 1 : 1;
 119   fsi ((unsigned)INT_MAX + 2);
 120   si = (unsigned)INT_MAX + 2;
 121   si = x ? (unsigned)INT_MAX + 2 : 1;
 122   fsi (UINT_MAX);
 123   si = UINT_MAX;
 124   fui (-1);
 125   ui = -1;
 126   ui = x ? -1 : 1U;
 127   fui (INT_MIN);
 128   ui = INT_MIN;
 129   ui = x ? INT_MIN : 1U;
 130 }