Patch by Dan Liew improving the description of getZExtValue (see discussion at http://keeda.stanford.edu/pipermail/klee-dev/2012-September/000928.html)

git-svn-id: https://llvm.org/svn/llvm-project/klee/trunk@166573 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 3 deletions

diff --git a/include/klee/Expr.h b/include/klee/Expr.h
index 5888d4d6..9d170dc5 100644
--- a/include/klee/Expr.h
+++ b/include/klee/Expr.h
@@ -326,10 +326,15 @@ public:
   /// native ConstantExpr APIs.
   const llvm::APInt &getAPValue() const { return value; }
 
-  /// getZExtValue - Return the constant value for a limited number of bits.
+  /// getZExtValue - Returns the constant value zero extended to the
+  /// return type of this method.
   ///
-  /// This routine should be used in situations where the width of the constant
-  /// is known to be limited to a certain number of bits.
+  ///\param bits - optional parameter that can be used to check that the
+  ///number of bits used by this constant is <= to the parameter
+  ///value. This is useful for checking that type casts won't truncate
+  ///useful bits.
+  ///
+  /// Example: unit8_t byte= (unit8_t) constant->getZExtValue(8);
   uint64_t getZExtValue(unsigned bits = 64) const {
     assert(getWidth() <= bits && "Value may be out of range!");
     return value.getZExtValue();