1//===--- APNumericStorage.h - Store APInt/APFloat in ASTContext -*- 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#ifndef LLVM_CLANG_AST_APNUMERICSTORAGE_H
10#define LLVM_CLANG_AST_APNUMERICSTORAGE_H
11
12#include "llvm/ADT/APFloat.h"
13#include "llvm/ADT/APInt.h"
14
15namespace clang {
16class ASTContext;
17
18/// Used by IntegerLiteral/FloatingLiteral/EnumConstantDecl to store the
19/// numeric without leaking memory.
20///
21/// For large floats/integers, APFloat/APInt will allocate memory from the heap
22/// to represent these numbers. Unfortunately, when we use a BumpPtrAllocator
23/// to allocate IntegerLiteral/FloatingLiteral nodes the memory associated with
24/// the APFloat/APInt values will never get freed. APNumericStorage uses
25/// ASTContext's allocator for memory allocation.
26class APNumericStorage {
27 union {
28 uint64_t VAL; ///< Used to store the <= 64 bits integer value.
29 uint64_t *pVal; ///< Used to store the >64 bits integer value.
30 };
31 unsigned BitWidth;
32
33 bool hasAllocation() const { return llvm::APInt::getNumWords(BitWidth) > 1; }
34
35 APNumericStorage(const APNumericStorage &) = delete;
36 void operator=(const APNumericStorage &) = delete;
37
38protected:
39 APNumericStorage() : VAL(0), BitWidth(0) {}
40
41 llvm::APInt getIntValue() const {
42 unsigned NumWords = llvm::APInt::getNumWords(BitWidth);
43 if (NumWords > 1)
44 return llvm::APInt(BitWidth, NumWords, pVal);
45 else
46 return llvm::APInt(BitWidth, VAL);
47 }
48 void setIntValue(const ASTContext &C, const llvm::APInt &Val);
49};
50
51class APIntStorage : private APNumericStorage {
52public:
53 llvm::APInt getValue() const { return getIntValue(); }
54 void setValue(const ASTContext &C, const llvm::APInt &Val) {
55 setIntValue(C, Val);
56 }
57};
58
59class APFloatStorage : private APNumericStorage {
60public:
61 llvm::APFloat getValue(const llvm::fltSemantics &Semantics) const {
62 return llvm::APFloat(Semantics, getIntValue());
63 }
64 void setValue(const ASTContext &C, const llvm::APFloat &Val) {
65 setIntValue(C, Val: Val.bitcastToAPInt());
66 }
67};
68
69} // end namespace clang
70
71#endif // LLVM_CLANG_AST_APNUMERICSTORAGE_H
72

source code of clang/include/clang/AST/APNumericStorage.h