- //===- OptionalDiagnostic.h - An optional diagnostic ------------*- C++ -*-===// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
- // 
- /// \file 
- /// Implements a partial diagnostic which may not be emitted. 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_CLANG_AST_OPTIONALDIAGNOSTIC_H 
- #define LLVM_CLANG_AST_OPTIONALDIAGNOSTIC_H 
-   
- #include "clang/AST/APValue.h" 
- #include "clang/Basic/PartialDiagnostic.h" 
- #include "llvm/ADT/APFloat.h" 
- #include "llvm/ADT/APSInt.h" 
- #include "llvm/ADT/SmallVector.h" 
- #include "llvm/ADT/StringRef.h" 
-   
- namespace clang { 
-   
- /// A partial diagnostic which we might know in advance that we are not going 
- /// to emit. 
- class OptionalDiagnostic { 
-   PartialDiagnostic *Diag; 
-   
- public: 
-   explicit OptionalDiagnostic(PartialDiagnostic *Diag = nullptr) : Diag(Diag) {} 
-   
-   template <typename T> OptionalDiagnostic &operator<<(const T &v) { 
-     if (Diag) 
-       *Diag << v; 
-     return *this; 
-   } 
-   
-   OptionalDiagnostic &operator<<(const llvm::APSInt &I) { 
-     if (Diag) { 
-       SmallVector<char, 32> Buffer; 
-       I.toString(Buffer); 
-       *Diag << StringRef(Buffer.data(), Buffer.size()); 
-     } 
-     return *this; 
-   } 
-   
-   OptionalDiagnostic &operator<<(const llvm::APFloat &F) { 
-     if (Diag) { 
-       // FIXME: Force the precision of the source value down so we don't 
-       // print digits which are usually useless (we don't really care here if 
-       // we truncate a digit by accident in edge cases).  Ideally, 
-       // APFloat::toString would automatically print the shortest 
-       // representation which rounds to the correct value, but it's a bit 
-       // tricky to implement. Could use std::to_chars. 
-       unsigned precision = llvm::APFloat::semanticsPrecision(F.getSemantics()); 
-       precision = (precision * 59 + 195) / 196; 
-       SmallVector<char, 32> Buffer; 
-       F.toString(Buffer, precision); 
-       *Diag << StringRef(Buffer.data(), Buffer.size()); 
-     } 
-     return *this; 
-   } 
-   
-   OptionalDiagnostic &operator<<(const llvm::APFixedPoint &FX) { 
-     if (Diag) { 
-       SmallVector<char, 32> Buffer; 
-       FX.toString(Buffer); 
-       *Diag << StringRef(Buffer.data(), Buffer.size()); 
-     } 
-     return *this; 
-   } 
- }; 
-   
- } // namespace clang 
-   
- #endif 
-