[cfe-commits] r53235 - /cfe/trunk/lib/AST/ExprConstant.cpp

[Eli Friedman]

On Tue, Jul 8, 2008 at 8:35 AM, Anders Carlsson <andersca at mac.com> wrote:
> +  uint64_t Offset = ResultLValue.getLValueOffset();
> +  if (E->getOpcode() == BinaryOperator::Add)
> +    Offset += AdditionalOffset.getZExtValue();
> +  else
> +    Offset -= AdditionalOffset.getZExtValue();

We probably don't want to succeed here for undefined pointer arithmetic.

> @@ -277,6 +348,41 @@
>   return APValue(Result);
>  }
>
> +APValue IntExprEvaluator::VisitSizeOfAlignOfTypeExpr
> +  (const SizeOfAlignOfTypeExpr *E)
> +{
> +  llvm::APSInt Result(32);
> +
> +  // Return the result in the right width.
> +  Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(E->getType())));
> +
> +  // sizeof(void) and __alignof__(void) = 1 as a gcc extension.
> +  if (E->getArgumentType()->isVoidType()) {
> +    Result = 1;
> +    Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
> +    return APValue(Result);
> +  }
> +
> +  // alignof always evaluates to a constant, sizeof does if arg is not VLA.
> +  if (E->isSizeOf() && !E->getArgumentType()->isConstantSizeType())
> +    return APValue();
> +
> +  // Get information about the size or align.
> +  if (E->getArgumentType()->isFunctionType()) {
> +    // GCC extension: sizeof(function) = 1.
> +    Result = E->isSizeOf() ? 1 : 4;
> +  } else {
> +    unsigned CharSize = Ctx.Target.getCharWidth();
> +    if (E->isSizeOf())
> +      Result = Ctx.getTypeSize(E->getArgumentType()) / CharSize;
> +    else
> +      Result = Ctx.getTypeAlign(E->getArgumentType()) / CharSize;
> +  }
> +
> +  Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
> +  return APValue(Result);
> +}
> +
>  }

It would be nice to avoid code duplication with the sizeof operator.

-Eli