Constant expression evaluation refactoring:

 - Remodel Expr::EvaluateAsInt to behave like the other EvaluateAs* functions,
   and add Expr::EvaluateKnownConstInt to capture the current fold-or-assert
   behaviour.
 - Factor out evaluation of bitfield bit widths.
 - Fix a few places which would evaluate an expression twice: once to determine
   whether it is a constant expression, then again to get the value.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141561 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 8 deletions

diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index 5dcecb9a11..8f61ea23cd 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -830,15 +830,11 @@ NotASpecialMember:;
 
     // If this is not a zero-length bit-field, then the class is not empty.
     if (data().Empty) {
-      if (!Field->getBitWidth())
+      if (!Field->isBitField() ||
+          (!Field->getBitWidth()->isTypeDependent() &&
+           !Field->getBitWidth()->isValueDependent() &&
+           Field->getBitWidthValue(Context) != 0))
         data().Empty = false;
-      else if (!Field->getBitWidth()->isTypeDependent() &&
-               !Field->getBitWidth()->isValueDependent()) {
-        llvm::APSInt Bits;
-        if (Field->getBitWidth()->isIntegerConstantExpr(Bits, Context))
-          if (!!Bits)
-            data().Empty = false;
-      } 
     }
   }