1 /*
2 * Copyright (c) 2021 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #ifndef PANDA_LIBPANDAFILE_BYTECODE_INSTRUCTION_INL_H_
17 #define PANDA_LIBPANDAFILE_BYTECODE_INSTRUCTION_INL_H_
18
19 #include "bytecode_instruction.h"
20 #include "macros.h"
21
22 namespace panda {
23
24 template <const BytecodeInstMode Mode>
25 template <class R, class S>
ReadHelper(size_t byteoffset,size_t bytecount,size_t offset,size_t width)26 inline auto BytecodeInst<Mode>::ReadHelper(size_t byteoffset, size_t bytecount, size_t offset, size_t width) const
27 {
28 constexpr size_t BYTE_WIDTH = 8;
29
30 size_t right_shift = offset % BYTE_WIDTH;
31
32 S v = 0;
33 for (size_t i = 0; i < bytecount; i++) {
34 S mask = static_cast<S>(ReadByte(byteoffset + i)) << (i * BYTE_WIDTH);
35 v |= mask;
36 }
37
38 v >>= right_shift;
39 size_t left_shift = sizeof(R) * BYTE_WIDTH - width;
40
41 // Do sign extension using arithmetic shift. It's implementation defined,
42 // so we check such behavior using static assert.
43 // NOLINTNEXTLINE(hicpp-signed-bitwise)
44 static_assert((-1 >> 1) == -1);
45
46 // NOLINTNEXTLINE(hicpp-signed-bitwise)
47 return static_cast<R>(v << left_shift) >> left_shift;
48 }
49
50 template <const BytecodeInstMode Mode>
51 // CODECHECK-NOLINTNEXTLINE(C_RULE_ID_COMMENT_LOCATION)
52 template <size_t offset, size_t width, bool is_signed /* = false */>
Read()53 inline auto BytecodeInst<Mode>::Read() const
54 {
55 constexpr size_t BYTE_WIDTH = 8;
56 constexpr size_t BYTE_OFFSET = offset / BYTE_WIDTH;
57 constexpr size_t BYTE_OFFSET_END = (offset + width + BYTE_WIDTH - 1) / BYTE_WIDTH;
58 constexpr size_t BYTE_COUNT = BYTE_OFFSET_END - BYTE_OFFSET;
59
60 using storage_type = helpers::TypeHelperT<BYTE_COUNT * BYTE_WIDTH, false>;
61 using return_type = helpers::TypeHelperT<width, is_signed>;
62
63 return ReadHelper<return_type, storage_type>(BYTE_OFFSET, BYTE_COUNT, offset, width);
64 }
65
66 template <const BytecodeInstMode Mode>
67 // CODECHECK-NOLINTNEXTLINE(C_RULE_ID_COMMENT_LOCATION)
68 template <bool is_signed /* = false */>
Read64(size_t offset,size_t width)69 inline auto BytecodeInst<Mode>::Read64(size_t offset, size_t width) const
70 {
71 constexpr size_t BIT64 = 64;
72 constexpr size_t BYTE_WIDTH = 8;
73
74 ASSERT((offset % BYTE_WIDTH) + width <= BIT64);
75
76 size_t byteoffset = offset / BYTE_WIDTH;
77 size_t byteoffset_end = (offset + width + BYTE_WIDTH - 1) / BYTE_WIDTH;
78 size_t bytecount = byteoffset_end - byteoffset;
79
80 using storage_type = helpers::TypeHelperT<BIT64, false>;
81 using return_type = helpers::TypeHelperT<BIT64, is_signed>;
82
83 return ReadHelper<return_type, storage_type>(byteoffset, bytecount, offset, width);
84 }
85
86 template <const BytecodeInstMode Mode>
GetSize()87 inline size_t BytecodeInst<Mode>::GetSize() const
88 {
89 return Size(GetFormat());
90 }
91
92 #include <bytecode_instruction-inl_gen.h>
93
94 } // namespace panda
95
96 #endif // PANDA_LIBPANDAFILE_BYTECODE_INSTRUCTION_INL_H_
97