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 *-*-* } } */
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 *-*-* } .-1 } */
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" { target c++ } .-1 } */
21 /* { dg-error "division by zero is not a constant.expression" "division" { target c++11 } .-2 } */
22 E5 = INT_MAX + 1, /* { dg-warning "integer overflow in expression" } */
23 /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } .-1 } */
24 /* Again, overflow in evaluated subexpression. */
25 E6 = 0 * (INT_MAX + 1), /* { dg-warning "integer overflow in expression" } */
26 /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } .-1 } */
27 /* A cast does not constitute overflow in conversion. */
28 E7 = (char) INT_MAX
29 };
30
31 struct s {
32 int a;
33 int : 0 * (1 / 0);
34 /* { dg-warning "division by zero" "" { target *-*-* } .-1 } */
35 /* { dg-error "division by zero is not a constant.expression" "division" { target c++11 } .-2 } */
36 /* { dg-error "width not an integer constant" "bit.field" { target c++ } .-3 } */
37 /* { dg-error "is not a constant expression" "division" { target c++ } .-4 } */
38 int : 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
39 /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } .-1 } */
40 };
41
42 void
f(void)43 f (void)
44 {
45 /* This expression is not required to be a constant expression, so
46 it should just involve undefined behavior at runtime. */
47 int c = INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
48
49 }
50
51 /* This expression is neither required to be constant. */
52 static int sc = INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
53
54
55 // Test for overflow in null pointer constant.
56 void *n = 0;
57 /* The first two of these involve overflow, so are not null pointer
58 constants. The third has the overflow in an unevaluated
59 subexpression, so is a null pointer constant. */
60 void *p = 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
61 /* { dg-warning "invalid conversion from 'int' to 'void" "null" { target *-*-* } .-1 } */
62
63 void *q = 0 * (1 / 0); /* { dg-warning "division by zero" } */
64 /* { dg-warning "invalid conversion from 'int' to 'void" "null" { target *-*-* } .-1 } */
65 void *r = (1 ? 0 : INT_MAX+1);
66 /* { dg-bogus "integer overflow in expression" "" { xfail *-*-* } .-1 } */
67 /* { dg-warning "invalid conversion from" "convert" { target c++11 } .-2 } */
68
69 void
g(int i)70 g (int i)
71 {
72 switch (i)
73 {
74 case 0 * (1/0):
75 /* { dg-warning "division by zero" "" { target *-*-* } .-1 } */
76 /* { dg-error "division by zero is not a constant expression" "division" { target c++11 } .-2 } */
77 /* { dg-error "not a constant expression" "constant" { target *-*-* } .-3 } */
78 ;
79 case 1 + 0 * (INT_MAX + 1): /* { dg-warning "integer overflow in expression" } */
80 /* { dg-warning "overflow in constant expression" "constant" { target *-*-* } .-1 } */
81 ;
82 }
83 }
84
85 int
h(void)86 h (void)
87 {
88 return INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
89 }
90
91 int
h1(void)92 h1 (void)
93 {
94 return INT_MAX + 1 - INT_MAX; /* { dg-warning "integer overflow in expression" } */
95 }
96
97 void fuc (unsigned char);
98 void fsc (signed char);
99
100 void
h2(void)101 h2 (void)
102 {
103 fsc (SCHAR_MAX + 1); /* { dg-warning "overflow in conversion from .int. to .signed char. changes value" } */
104 fsc (SCHAR_MIN - 1); /* { dg-warning "overflow in conversion from .int. to .signed char. changes value" } */
105 fsc (UCHAR_MAX); /* { dg-warning "overflow in conversion from .int. to .signed char. changes value" } */
106 fsc (UCHAR_MAX + 1); /* { dg-warning "overflow in conversion from .int. to .signed char. changes value" } */
107 fuc (-1);
108 fuc (UCHAR_MAX + 1); /* { dg-warning "unsigned conversion from .int. to .unsigned char. changes value" } */
109 fuc (SCHAR_MIN);
110 fuc (SCHAR_MIN - 1); /* { dg-warning "unsigned conversion from .int. to .unsigned char. changes value" } */
111 fuc (-UCHAR_MAX); /* { dg-warning "unsigned conversion from .int. to .unsigned char. changes value" } */
112 }
113
114 void fui (unsigned int);
115 void fsi (signed int);
116
117 int si;
118 unsigned ui;
119
120 void
h2i(int x)121 h2i (int x)
122 {
123 /* For some reason, we only give certain warnings for implicit
124 conversions among values of the same precision with -Wconversion,
125 while we don't give others at all. */
126 fsi ((unsigned)INT_MAX + 1);
127 si = (unsigned)INT_MAX + 1;
128 si = x ? (unsigned)INT_MAX + 1 : 1;
129 fsi ((unsigned)INT_MAX + 2);
130 si = (unsigned)INT_MAX + 2;
131 si = x ? (unsigned)INT_MAX + 2 : 1;
132 fsi (UINT_MAX);
133 si = UINT_MAX;
134 fui (-1);
135 ui = -1;
136 ui = x ? -1 : 1U;
137 fui (INT_MIN);
138 ui = INT_MIN;
139 ui = x ? INT_MIN : 1U;
140 }
141