/* Test for diagnostics for constant overflow. Test with -Wconversion. */ /* Origin: Joseph Myers <joseph@codesourcery.com> */ /* { dg-do compile } */ /* { dg-options "-std=c99 -Wconversion" } */ #include <limits.h> enum e { E0 = INT_MAX, /* Unsigned overflow wraps around. */ E1 = UINT_MAX + 1, /* Overflow in an unevaluated part of an expression is OK (example in the standard). */ E2 = 2 || 1 / 0, E3 = 1 / 0, /* { dg-warning "warning: division by zero" } */ /* { dg-error "error: enumerator value for 'E3' is not an integer constant" "enum error" { target *-*-* } 15 } */ /* But as in DR#031, the 1/0 in an evaluated subexpression means the whole expression violates the constraints. */ E4 = 0 * (1 / 0), /* { dg-warning "warning: division by zero" } */ /* { dg-error "error: enumerator value for 'E4' is not an integer constant" "enum error" { xfail *-*-* } 19 } */ E5 = INT_MAX + 1, /* { dg-warning "warning: integer overflow in expression" } */ /* Again, overflow in evaluated subexpression. */ E6 = 0 * (INT_MAX + 1), /* { dg-warning "warning: integer overflow in expression" } */ /* A cast does not constitute overflow in conversion. */ E7 = (char) INT_MAX }; struct s { int a; int : 0 * (1 / 0); /* { dg-warning "warning: division by zero" } */ int : 0 * (INT_MAX + 1); /* { dg-warning "warning: integer overflow in expression" } */ }; void f (void) { /* This expression is not required to be a constant expression, so it should just involve undefined behavior at runtime. */ int c = INT_MAX + 1; /* { dg-warning "warning: integer overflow in expression" } */ } /* But this expression does need to be constant. */ static int sc = INT_MAX + 1; /* { dg-warning "warning: integer overflow in expression" } */ /* The first two of these involve overflow, so are not null pointer constants. The third has the overflow in an unevaluated subexpression, so is a null pointer constant. */ void *p = 0 * (INT_MAX + 1); /* { dg-warning "warning: integer overflow in expression" } */ /* { dg-warning "warning: initialization makes pointer from integer without a cast" "null" { target *-*-* } 48 } */ void *q = 0 * (1 / 0); /* { dg-warning "warning: division by zero" } */ /* { dg-warning "warning: initialization makes pointer from integer without a cast" "null" { xfail *-*-* } 50 } */ void *r = (1 ? 0 : INT_MAX+1); void g (int i) { switch (i) { case 0 * (1/0): /* { dg-warning "warning: division by zero" } */ ; case 1 + 0 * (INT_MAX + 1): /* { dg-warning "warning: integer overflow in expression" } */ ; } } int h (void) { return INT_MAX + 1; /* { dg-warning "warning: integer overflow in expression" } */ } int h1 (void) { return INT_MAX + 1 - INT_MAX; /* { dg-warning "warning: integer overflow in expression" } */ } void fuc (unsigned char); void fsc (signed char); void h2 (void) { fsc (SCHAR_MAX + 1); /* { dg-warning "warning: passing argument 1 of 'fsc' with different width due to prototype" "-Wconversion" { target *-*-* } 84 } */ fsc (SCHAR_MIN - 1); /* { dg-warning "warning: overflow in implicit constant conversion" } */ /* { dg-warning "warning: passing argument 1 of 'fsc' with different width due to prototype" "-Wconversion" { target *-*-* } 86 } */ fsc (UCHAR_MAX); /* { dg-warning "warning: passing argument 1 of 'fsc' with different width due to prototype" "-Wconversion" { target *-*-* } 88 } */ fsc (UCHAR_MAX + 1); /* { dg-warning "warning: overflow in implicit constant conversion" } */ /* { dg-warning "warning: passing argument 1 of 'fsc' with different width due to prototype" "-Wconversion" { target *-*-* } 90 } */ fuc (-1); /* { dg-warning "warning: negative integer implicitly converted to unsigned type" } */ /* { dg-warning "warning: passing argument 1 of 'fuc' with different width due to prototype" "-Wconversion" { target *-*-* } 92 } */ fuc (UCHAR_MAX + 1); /* { dg-warning "warning: large integer implicitly truncated to unsigned type" } */ /* { dg-warning "warning: passing argument 1 of 'fuc' with different width due to prototype" "-Wconversion" { target *-*-* } 94 } */ fuc (SCHAR_MIN); /* { dg-warning "warning: negative integer implicitly converted to unsigned type" } */ /* { dg-warning "warning: passing argument 1 of 'fuc' with different width due to prototype" "-Wconversion" { target *-*-* } 96 } */ fuc (SCHAR_MIN - 1); /* { dg-warning "warning: large integer implicitly truncated to unsigned type" } */ /* { dg-warning "warning: passing argument 1 of 'fuc' with different width due to prototype" "-Wconversion" { target *-*-* } 98 } */ fuc (-UCHAR_MAX); /* { dg-warning "warning: large integer implicitly truncated to unsigned type" } */ /* { dg-warning "warning: passing argument 1 of 'fuc' with different width due to prototype" "-Wconversion" { target *-*-* } 100 } */ } void fui (unsigned int); void fsi (signed int); int si; unsigned ui; void h2i (int x) { /* For some reason, we only give certain warnings for implicit conversions among values of the same precision with -Wconversion, while we don't give others at all. */ fsi ((unsigned)INT_MAX + 1); /* { dg-warning "warning: passing argument 1 of 'fsi' as signed due to prototype" } */ si = (unsigned)INT_MAX + 1; si = x ? (unsigned)INT_MAX + 1 : 1; fsi ((unsigned)INT_MAX + 2); /* { dg-warning "warning: passing argument 1 of 'fsi' as signed due to prototype" } */ si = (unsigned)INT_MAX + 2; si = x ? (unsigned)INT_MAX + 2 : 1; fsi (UINT_MAX); /* { dg-warning "warning: passing argument 1 of 'fsi' as signed due to prototype" } */ si = UINT_MAX; fui (-1); /* { dg-warning "warning: negative integer implicitly converted to unsigned type" } */ /* { dg-warning "warning: passing argument 1 of 'fui' as unsigned due to prototype" "-Wconversion" { target *-*-* } 124 } */ ui = -1; /* { dg-warning "warning: negative integer implicitly converted to unsigned type" } */ ui = x ? -1 : 1U; /* { dg-warning "warning: negative integer implicitly converted to unsigned type" } */ fui (INT_MIN); /* { dg-warning "warning: negative integer implicitly converted to unsigned type" } */ /* { dg-warning "warning: passing argument 1 of 'fui' as unsigned due to prototype" "-Wconversion" { target *-*-* } 128 } */ ui = INT_MIN; /* { dg-warning "warning: negative integer implicitly converted to unsigned type" } */ ui = x ? INT_MIN : 1U; /* { dg-warning "warning: negative integer implicitly converted to unsigned type" } */ }