1//===- OptionalDiagnostic.h - An optional diagnostic ------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// Implements a partial diagnostic which may not be emitted.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_AST_OPTIONALDIAGNOSTIC_H
15#define LLVM_CLANG_AST_OPTIONALDIAGNOSTIC_H
16
17#include "clang/AST/APValue.h"
18#include "clang/Basic/PartialDiagnostic.h"
19#include "llvm/ADT/APFloat.h"
20#include "llvm/ADT/APSInt.h"
21#include "llvm/ADT/SmallVector.h"
22#include "llvm/ADT/StringRef.h"
23
24namespace clang {
25
26/// A partial diagnostic which we might know in advance that we are not going
27/// to emit.
28class OptionalDiagnostic {
29 PartialDiagnostic *Diag;
30
31public:
32 explicit OptionalDiagnostic(PartialDiagnostic *Diag = nullptr) : Diag(Diag) {}
33
34 template <typename T> OptionalDiagnostic &operator<<(const T &v) {
35 if (Diag)
36 *Diag << v;
37 return *this;
38 }
39
40 OptionalDiagnostic &operator<<(const llvm::APSInt &I) {
41 if (Diag) {
42 SmallVector<char, 32> Buffer;
43 I.toString(Str&: Buffer);
44 *Diag << StringRef(Buffer.data(), Buffer.size());
45 }
46 return *this;
47 }
48
49 OptionalDiagnostic &operator<<(const llvm::APFloat &F) {
50 if (Diag) {
51 // FIXME: Force the precision of the source value down so we don't
52 // print digits which are usually useless (we don't really care here if
53 // we truncate a digit by accident in edge cases). Ideally,
54 // APFloat::toString would automatically print the shortest
55 // representation which rounds to the correct value, but it's a bit
56 // tricky to implement. Could use std::to_chars.
57 unsigned precision = llvm::APFloat::semanticsPrecision(F.getSemantics());
58 precision = (precision * 59 + 195) / 196;
59 SmallVector<char, 32> Buffer;
60 F.toString(Str&: Buffer, FormatPrecision: precision);
61 *Diag << StringRef(Buffer.data(), Buffer.size());
62 }
63 return *this;
64 }
65
66 OptionalDiagnostic &operator<<(const llvm::APFixedPoint &FX) {
67 if (Diag) {
68 SmallVector<char, 32> Buffer;
69 FX.toString(Str&: Buffer);
70 *Diag << StringRef(Buffer.data(), Buffer.size());
71 }
72 return *this;
73 }
74};
75
76} // namespace clang
77
78#endif
79