1 files changed, 59 insertions, 0 deletions
diff --git a/test/SemaCXX/warn-bitfield-enum-conversion.cpp b/test/SemaCXX/warn-bitfield-enum-conversion.cpp
new file mode 100644
index 000000000000..7e7a202f8d2b
--- /dev/null
+++ b/test/SemaCXX/warn-bitfield-enum-conversion.cpp
@@ -0,0 +1,59 @@
+// RUN: %clang_cc1 -std=c++11 -triple x86_64-windows-msvc -verify %s -Wbitfield-enum-conversion
+// RUN: %clang_cc1 -std=c++11 -triple x86_64-linux -verify %s -Wbitfield-enum-conversion
+
+enum TwoBits { Hi1 = 3 } two_bits;
+enum TwoBitsSigned { Lo2 = -2, Hi2 = 1 } two_bits_signed;
+enum ThreeBits { Hi3 = 7 } three_bits;
+enum ThreeBitsSigned { Lo4 = -4, Hi4 = 3 } three_bits_signed;
+enum TwoBitsFixed : unsigned { Hi5 = 3 } two_bits_fixed;
+
+struct Foo {
+  unsigned two_bits : 2;        // expected-note 2 {{widen this field to 3 bits}} expected-note 2 {{type signed}}
+  int two_bits_signed : 2;      // expected-note 2 {{widen this field to 3 bits}} expected-note 1 {{type unsigned}}
+  unsigned three_bits : 3;      // expected-note 2 {{type signed}}
+  int three_bits_signed : 3;    // expected-note 1 {{type unsigned}}
+
+#ifdef _WIN32
+  // expected-note@+2 {{type unsigned}}
+#endif
+  ThreeBits three_bits_enum : 3;
+  ThreeBits four_bits_enum : 4;
+};
+
+void f() {
+  Foo f;
+
+  f.two_bits = two_bits;
+  f.two_bits = two_bits_signed;            // expected-warning {{negative enumerators}}
+  f.two_bits = three_bits;                 // expected-warning {{not wide enough}}
+  f.two_bits = three_bits_signed;          // expected-warning {{negative enumerators}} expected-warning {{not wide enough}}
+  f.two_bits = two_bits_fixed;
+
+  f.two_bits_signed = two_bits;            // expected-warning {{needs an extra bit}}
+  f.two_bits_signed = two_bits_signed;
+  f.two_bits_signed = three_bits;          // expected-warning {{not wide enough}}
+  f.two_bits_signed = three_bits_signed;   // expected-warning {{not wide enough}}
+
+  f.three_bits = two_bits;
+  f.three_bits = two_bits_signed;          // expected-warning {{negative enumerators}}
+  f.three_bits = three_bits;
+  f.three_bits = three_bits_signed;        // expected-warning {{negative enumerators}}
+
+  f.three_bits_signed = two_bits;
+  f.three_bits_signed = two_bits_signed;
+  f.three_bits_signed = three_bits;        // expected-warning {{needs an extra bit}}
+  f.three_bits_signed = three_bits_signed;
+
+#ifdef _WIN32
+  // Enums on Windows are always implicitly 'int', which is signed, so you need
+  // an extra bit to store values that set the MSB. This is not true on SysV
+  // platforms like Linux.
+  // expected-warning@+2 {{needs an extra bit}}
+#endif
+  f.three_bits_enum = three_bits;
+  f.four_bits_enum = three_bits;
+
+  // Explicit casts suppress the warning.
+  f.two_bits = (unsigned)three_bits_signed;
+  f.two_bits = static_cast<unsigned>(three_bits_signed);
+}