Take into account the zero sign bit for positive numbers when computing the bit
width of an enum with negative values in IntRange. Include a test for
-Wtautological-constant-out-of-range-compare where this had manifested.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@168126 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 05fa2a0..8e0a983 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -3922,7 +3922,11 @@
unsigned NumPositive = Enum->getNumPositiveBits();
unsigned NumNegative = Enum->getNumNegativeBits();
- return IntRange(std::max(NumPositive, NumNegative), NumNegative == 0);
+ if (NumNegative == 0)
+ return IntRange(NumPositive, true/*NonNegative*/);
+ else
+ return IntRange(std::max(NumPositive + 1, NumNegative),
+ false/*NonNegative*/);
}
const BuiltinType *BT = cast<BuiltinType>(T);
diff --git a/test/SemaCXX/compare.cpp b/test/SemaCXX/compare.cpp
index 05980ba..c76efe9 100644
--- a/test/SemaCXX/compare.cpp
+++ b/test/SemaCXX/compare.cpp
@@ -338,3 +338,13 @@
(void)((unsigned char)other != (unsigned short)(0x100)); // expected-warning{{true}}
(void)((unsigned short)other != (unsigned char)(0xff));
}
+
+void test8(int x) {
+ enum E {
+ Negative = -1,
+ Positive = 1
+ };
+
+ (void)((E)x == 1);
+ (void)((E)x == -1);
+}