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 | |
15 | namespace clang { |
16 | class 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. |
26 | class 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 | |
38 | protected: |
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 | |
51 | class APIntStorage : private APNumericStorage { |
52 | public: |
53 | llvm::APInt getValue() const { return getIntValue(); } |
54 | void setValue(const ASTContext &C, const llvm::APInt &Val) { |
55 | setIntValue(C, Val); |
56 | } |
57 | }; |
58 | |
59 | class APFloatStorage : private APNumericStorage { |
60 | public: |
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 | |