diff options
Diffstat (limited to 'test/Sema/tautological-unsigned-enum-zero-compare.cpp')
| -rw-r--r-- | test/Sema/tautological-unsigned-enum-zero-compare.cpp | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/test/Sema/tautological-unsigned-enum-zero-compare.cpp b/test/Sema/tautological-unsigned-enum-zero-compare.cpp new file mode 100644 index 000000000000..a733b6edfc03 --- /dev/null +++ b/test/Sema/tautological-unsigned-enum-zero-compare.cpp @@ -0,0 +1,147 @@ +// RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-linux-gnu -fsyntax-only \ +// RUN: -verify=unsigned,unsigned-signed %s +// RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-win32 -fsyntax-only \ +// RUN: -verify=unsigned-signed %s +// RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-win32 -fsyntax-only \ +// RUN: -Wno-tautological-unsigned-enum-zero-compare \ +// 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 |