[cfe-commits] r168126 - in /cfe/trunk: lib/Sema/SemaChecking.cpp test/SemaCXX/compare.cpp

[Richard Trieu]

Author: rtrieu
Date: Thu Nov 15 19:32:40 2012
New Revision: 168126

URL: http://llvm.org/viewvc/llvm-project?rev=168126&view=rev
Log:
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.


Modified:
    cfe/trunk/lib/Sema/SemaChecking.cpp
    cfe/trunk/test/SemaCXX/compare.cpp

Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=168126&r1=168125&r2=168126&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Thu Nov 15 19:32:40 2012
@@ -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);

Modified: cfe/trunk/test/SemaCXX/compare.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/compare.cpp?rev=168126&r1=168125&r2=168126&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/compare.cpp (original)
+++ cfe/trunk/test/SemaCXX/compare.cpp Thu Nov 15 19:32:40 2012
@@ -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);
+}