1 /* Test for diagnostics for constant overflow. Test with -Wtraditional-conversion. */
2 /* Origin: Joseph Myers <joseph@codesourcery.com> */
3 /* { dg-do compile } */
4 /* { dg-options "-std=c99 -Wtraditional-conversion" } */
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,
15 E3 = 1 / 0, /* { dg-warning "division by zero" } */
16 /* { dg-error "enumerator value for 'E3' is not an integer constant" "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 *-*-* } .-1 } */
21 E5 = INT_MAX + 1, /* { dg-warning "integer overflow in expression" } */
22 /* Again, overflow in evaluated subexpression. */
23 E6 = 0 * (INT_MAX + 1), /* { dg-warning "integer overflow in expression" } */
24 /* A cast does not constitute overflow in conversion. */
25 E7 = (char) INT_MAX
26 };
27
28 struct s {
29 int a;
30 int : 0 * (1 / 0); /* { dg-warning "division by zero" } */
31 /* { dg-error "not an integer constant" "integer constant" { target *-*-* } .-1 } */
32 int : 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
33 };
34
35 void
f(void)36 f (void)
37 {
38 /* This expression is not required to be a constant expression, so
39 it should just involve undefined behavior at runtime. */
40 int c = INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
41 }
42
43 /* But this expression does need to be constant. */
44 static int sc = INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
45
46 /* The first two of these involve overflow, so are not null pointer
47 constants. The third has the overflow in an unevaluated
48 subexpression, so is a null pointer constant. */
49 void *p = 0 * (INT_MAX + 1); /* { dg-warning "integer overflow in expression" } */
50 /* { dg-warning "initialization of 'void \\*' from 'int' makes pointer from integer without a cast" "null" { target *-*-* } .-1 } */
51 void *q = 0 * (1 / 0); /* { dg-warning "division by zero" } */
52 /* { dg-error "initializer element is not constant" "constant" { target *-*-* } .-1 } */
53 /* { dg-warning "initialization of 'void \\*' from 'int' makes pointer from integer without a cast" "null" { target *-*-* } .-2 } */
54 void *r = (1 ? 0 : INT_MAX+1);
55
56 void
g(int i)57 g (int i)
58 {
59 switch (i)
60 {
61 case 0 * (1/0): /* { dg-warning "division by zero" } */
62 /* { dg-error "case label does not reduce to an integer constant" "constant" { target *-*-* } .-1 } */
63 ;
64 case 1 + 0 * (INT_MAX + 1): /* { dg-warning "integer overflow in expression" } */
65 ;
66 }
67 }
68
69 int
h(void)70 h (void)
71 {
72 return INT_MAX + 1; /* { dg-warning "integer overflow in expression" } */
73 }
74
75 int
h1(void)76 h1 (void)
77 {
78 return INT_MAX + 1 - INT_MAX; /* { dg-warning "integer overflow in expression" } */
79 }
80
81 void fuc (unsigned char);
82 void fsc (signed char);
83
84 void
h2(void)85 h2 (void)
86 {
87 fsc (SCHAR_MAX + 1);
88 /* { dg-warning "passing argument 1 of 'fsc' with different width due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
89 fsc (SCHAR_MIN - 1); /* { dg-warning "overflow in conversion from .int. to .signed char. changes value" } */
90 /* { dg-warning "passing argument 1 of 'fsc' with different width due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
91 fsc (UCHAR_MAX);
92 /* { dg-warning "passing argument 1 of 'fsc' with different width due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
93 fsc (UCHAR_MAX + 1); /* { dg-warning "overflow in conversion from 'int' to 'signed char' changes value " } */
94 /* { dg-warning "passing argument 1 of 'fsc' with different width due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
95 fuc (-1);
96 /* { dg-warning "passing argument 1 of 'fuc' with different width due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
97 fuc (UCHAR_MAX + 1); /* { dg-warning "unsigned conversion from .int. to .unsigned char. changes value " } */
98 /* { dg-warning "passing argument 1 of 'fuc' with different width due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
99 fuc (SCHAR_MIN);
100 /* { dg-warning "passing argument 1 of 'fuc' with different width due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
101 fuc (SCHAR_MIN - 1); /* { dg-warning "unsigned conversion from .int. to .unsigned char. changes value " } */
102 /* { dg-warning "passing argument 1 of 'fuc' with different width due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
103 fuc (-UCHAR_MAX); /* { dg-warning "unsigned conversion from .int. to .unsigned char. changes value" } */
104 /* { dg-warning "passing argument 1 of 'fuc' with different width due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
105 }
106
107 void fui (unsigned int);
108 void fsi (signed int);
109
110 int si;
111 unsigned ui;
112
113 void
h2i(int x)114 h2i (int x)
115 {
116 /* For some reason, we only give certain warnings for implicit
117 conversions among values of the same precision with -Wtraditional-conversion,
118 while we don't give others at all. */
119 fsi ((unsigned)INT_MAX + 1); /* { dg-warning "passing argument 1 of 'fsi' as signed due to prototype" } */
120 si = (unsigned)INT_MAX + 1;
121 si = x ? (unsigned)INT_MAX + 1 : 1;
122 fsi ((unsigned)INT_MAX + 2); /* { dg-warning "passing argument 1 of 'fsi' as signed due to prototype" } */
123 si = (unsigned)INT_MAX + 2;
124 si = x ? (unsigned)INT_MAX + 2 : 1;
125 fsi (UINT_MAX); /* { dg-warning "passing argument 1 of 'fsi' as signed due to prototype" } */
126 si = UINT_MAX;
127 fui (-1);
128 /* { dg-warning "passing argument 1 of 'fui' as unsigned due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
129 ui = -1;
130 ui = x ? -1 : 1U;
131 fui (INT_MIN);
132 /* { dg-warning "passing argument 1 of 'fui' as unsigned due to prototype" "-Wtraditional-conversion" { target *-*-* } .-1 } */
133 ui = INT_MIN;
134 ui = x ? INT_MIN : 1U;
135 }
136