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// RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-linux-gnu -fsyntax-only \
// RUN: -Wtautological-unsigned-enum-zero-compare \
// RUN: -verify=unsigned,unsigned-signed %s
// RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-win32 -fsyntax-only \
// RUN: -Wtautological-unsigned-enum-zero-compare \
// RUN: -verify=unsigned-signed %s
// RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-win32 -fsyntax-only \
// RUN: -verify=silence %s
// silence-no-diagnostics
int main() {
// On Windows, all enumerations have a fixed underlying type, which is 'int'
// if not otherwise specified, so A is identical to C on Windows. Otherwise,
// we follow the C++ rules, which say that the only valid values of A are 0
// and 1.
enum A { A_foo = 0, A_bar, };
enum A a;
enum B : unsigned { B_foo = 0, B_bar, };
enum B b;
enum C : signed { C_foo = 0, C_bar, };
enum C c;
if (a < 0) // unsigned-warning {{comparison of unsigned enum expression < 0 is always false}}
return 0;
if (0 >= a)
return 0;
if (a > 0)
return 0;
if (0 <= a) // unsigned-warning {{comparison of 0 <= unsigned enum expression is always true}}
return 0;
if (a <= 0)
return 0;
if (0 > a) // unsigned-warning {{comparison of 0 > unsigned enum expression is always false}}
return 0;
if (a >= 0) // unsigned-warning {{comparison of unsigned enum expression >= 0 is always true}}
return 0;
if (0 < a)
return 0;
// FIXME: As below, the issue here is that the enumeration is promoted to
// unsigned.
if (a < 0U) // unsigned-signed-warning {{comparison of unsigned enum expression < 0 is always false}}
return 0;
if (0U >= a)
return 0;
if (a > 0U)
return 0;
if (0U <= a) // unsigned-signed-warning {{comparison of 0 <= unsigned enum expression is always true}}
return 0;
if (a <= 0U)
return 0;
if (0U > a) // unsigned-signed-warning {{comparison of 0 > unsigned enum expression is always false}}
return 0;
if (a >= 0U) // unsigned-signed-warning {{comparison of unsigned enum expression >= 0 is always true}}
return 0;
if (0U < a)
return 0;
if (b < 0) // unsigned-signed-warning {{comparison of unsigned enum expression < 0 is always false}}
return 0;
if (0 >= b)
return 0;
if (b > 0)
return 0;
if (0 <= b) // unsigned-signed-warning {{comparison of 0 <= unsigned enum expression is always true}}
return 0;
if (b <= 0)
return 0;
if (0 > b) // unsigned-signed-warning {{comparison of 0 > unsigned enum expression is always false}}
return 0;
if (b >= 0) // unsigned-signed-warning {{comparison of unsigned enum expression >= 0 is always true}}
return 0;
if (0 < b)
return 0;
if (b < 0U) // unsigned-signed-warning {{comparison of unsigned enum expression < 0 is always false}}
return 0;
if (0U >= b)
return 0;
if (b > 0U)
return 0;
if (0U <= b) // unsigned-signed-warning {{comparison of 0 <= unsigned enum expression is always true}}
return 0;
if (b <= 0U)
return 0;
if (0U > b) // unsigned-signed-warning {{comparison of 0 > unsigned enum expression is always false}}
return 0;
if (b >= 0U) // unsigned-signed-warning {{comparison of unsigned enum expression >= 0 is always true}}
return 0;
if (0U < b)
return 0;
if (c < 0)
return 0;
if (0 >= c)
return 0;
if (c > 0)
return 0;
if (0 <= c)
return 0;
if (c <= 0)
return 0;
if (0 > c)
return 0;
if (c >= 0)
return 0;
if (0 < c)
return 0;
// FIXME: These diagnostics are terrible. The issue here is that the signed
// enumeration value was promoted to an unsigned type.
if (c < 0U) // unsigned-signed-warning {{comparison of unsigned enum expression < 0 is always false}}
return 0;
if (0U >= c)
return 0;
if (c > 0U)
return 0;
if (0U <= c) // unsigned-signed-warning {{comparison of 0 <= unsigned enum expression is always true}}
return 0;
if (c <= 0U)
return 0;
if (0U > c) // unsigned-signed-warning {{comparison of 0 > unsigned enum expression is always false}}
return 0;
if (c >= 0U) // unsigned-signed-warning {{comparison of unsigned enum expression >= 0 is always true}}
return 0;
if (0U < c)
return 0;
return 1;
}
namespace crash_enum_zero_width {
int test() {
enum A : unsigned {
A_foo = 0
};
enum A a;
// used to crash in llvm::APSInt::getMaxValue()
if (a < 0) // unsigned-signed-warning {{comparison of unsigned enum expression < 0 is always false}}
return 0;
return 1;
}
} // namespace crash_enum_zero_width
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