[cfe-commits] [PATCH] Use the new APFloat::convertToInt(APSInt) function (issue4728042)

[Eli Friedman]

On Thu, Jul 14, 2011 at 5:06 PM,  <jyasskin at gmail.com> wrote:
> Reviewers: cfe-commits_cs.uiuc.edu,
>
> Message:
> Initial diff at
> http://codereview.appspot.com/download/issue4728042_1.diff.
>
> Description:
> Use the new APFloat::convertToInt(APSInt) function to simplify uses of
> convertToInt(integerParts*) and make them more reliable.
>
> Relies on http://codereview.appspot.com/4738043.
>
> Please review this at http://codereview.appspot.com/4728042/
>
> Affected files:
>   M lib/AST/ExprConstant.cpp
>   M lib/Sema/SemaChecking.cpp
>
>
> Index: lib/AST/ExprConstant.cpp
> diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
> index
> 9943222b1dd30d9761731fca984d20d6b578f788..03c0747efba9e8ed9451607b6a33c8b1c9716196
> 100644
> --- a/lib/AST/ExprConstant.cpp
> +++ b/lib/AST/ExprConstant.cpp
> @@ -223,12 +223,10 @@ static APSInt HandleFloatToIntCast(QualType DestType,
> QualType SrcType,
>    // Determine whether we are converting to unsigned or signed.
>    bool DestSigned = DestType->isSignedIntegerOrEnumerationType();
>
> -  // FIXME: Warning for overflow.
> -  uint64_t Space[4];
> +  APSInt Result(DestWidth, !DestSigned);
>    bool ignored;
> -  (void)Value.convertToInteger(Space, DestWidth, DestSigned,
> -                               llvm::APFloat::rmTowardZero, &ignored);
> -  return APSInt(llvm::APInt(DestWidth, 4, Space), !DestSigned);
> +  (void)Value.convertToInteger(Result, llvm::APFloat::rmTowardZero,
> &ignored);
> +  return Result;
>  }

Why are you removing the "FIXME: Warning for overflow" comment?  The
issue still exists...

>  static APFloat HandleFloatToFloatCast(QualType DestType, QualType SrcType,
> Index: lib/Sema/SemaChecking.cpp
> diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
> index
> 267cda8f4016ca935873eac6d22bb82906201051..d1990f3061f353f3152a33d450b971b445d95a10
> 100644
> --- a/lib/Sema/SemaChecking.cpp
> +++ b/lib/Sema/SemaChecking.cpp
> @@ -2990,17 +2990,15 @@ void DiagnoseFloatingLiteralImpCast(Sema &S,
> FloatingLiteral *FL, QualType T,
>    if (&Value.getSemantics() == &llvm::APFloat::PPCDoubleDouble)
>      return;
>
> -  // Try to convert this exactly to an 64-bit integer. FIXME: It would be
> -  // nice to support arbitrarily large integers here.
> +  // Try to convert this exactly to an integer.
>    bool isExact = false;
> -  uint64_t IntegerPart;
> -  if (Value.convertToInteger(&IntegerPart, 64, /*isSigned=*/true,
> +  llvm::APSInt IntegerValue(S.Context.getIntWidth(T),
> +                            /*isUnsigned=*/false);
> +  if (Value.convertToInteger(IntegerValue,
>                               llvm::APFloat::rmTowardZero, &isExact)
>        != llvm::APFloat::opOK || !isExact)
>      return;
>
> -  llvm::APInt IntegerValue(64, IntegerPart, /*isSigned=*/true);
> -
>    std::string LiteralValue = IntegerValue.toString(10, /*isSigned=*/true);
>    S.Diag(FL->getExprLoc(), diag::note_fix_integral_float_as_integer)
>      << FixItHint::CreateReplacement(FL->getSourceRange(), LiteralValue);

I was going to ask why you're forcing this to be signed, but then I
realized it's impossible to write a negative floating-point literal.
:)

-Eli