1/*
2 * Copyright 2014 Google, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met: redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer;
8 * redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution;
11 * neither the name of the copyright holders nor the names of its
12 * contributors may be used to endorse or promote products derived from
13 * this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Authors: Gabe Black
28 */
29
30#include <gtest/gtest.h>
31
32#include <cassert>
33#include <iostream>
34#include <type_traits>
35
36#include "base/bitunion.hh"
37#include "base/cprintf.hh"
38
39using namespace std;
40
41namespace {
42
43BitUnion64(SixtyFour)
44    Bitfield<39, 32> byte5;
45    Bitfield<2> bit2;
46    BitfieldRO<39, 32> byte5RO;
47    BitfieldWO<39, 32> byte5WO;
48    SubBitUnion(byte6, 47, 40)
49        Bitfield<43, 42> bits43To42;
50        Bitfield<41> bit41;
51        SignedBitfield<41> bit41Signed;
52    EndSubBitUnion(byte6)
53    SignedBitfield<47, 40> byte6Signed;
54    SignedBitfieldRO<47, 40> byte6SignedRO;
55    SignedBitfieldWO<47, 40> byte6SignedWO;
56EndBitUnion(SixtyFour)
57
58BitUnion64(EmptySixtyFour)
59EndBitUnion(EmptySixtyFour)
60
61BitUnion32(EmptyThirtyTwo)
62EndBitUnion(EmptyThirtyTwo)
63
64BitUnion16(EmptySixteen)
65EndBitUnion(EmptySixteen)
66
67BitUnion8(EmptyEight)
68EndBitUnion(EmptyEight)
69
70class SplitField
71{
72  protected:
73    BitUnion64(In)
74        Bitfield<15, 12> high;
75        Bitfield<7, 4> low;
76    EndBitUnion(In)
77
78    BitUnion64(Out)
79        Bitfield<7, 4> high;
80        Bitfield<3, 0> low;
81    EndBitUnion(Out)
82  public:
83    uint64_t
84    getter(const uint64_t &storage) const
85    {
86        Out out = 0;
87        In in = storage;
88        out.high = in.high;
89        out.low = in.low;
90        return out;
91    }
92
93    void
94    setter(uint64_t &storage, uint64_t val)
95    {
96        Out out = val;
97        In in = 0;
98        in.high = out.high;
99        in.low = out.low;
100        storage = in;
101    }
102};
103
104BitUnion64(Split)
105    BitfieldType<SplitField> split;
106EndBitUnion(Split)
107
108struct ContainingStruct
109{
110    BitUnion64(Contained)
111        Bitfield<63, 60> topNibble;
112    EndBitUnion(Contained)
113
114    Contained contained;
115};
116
117uint64_t
118containingFunc(uint64_t init_val, uint64_t fieldVal)
119{
120    BitUnion32(Contained)
121        Bitfield<16, 15> field;
122    EndBitUnion(Contained)
123
124    Contained contained = init_val;
125    contained.field = fieldVal;
126    return contained;
127}
128
129} // anonymous namespace
130
131// Declare these as global so g++ doesn't ignore them. Initialize them in
132// various ways.
133EmptySixtyFour emptySixtyFour = 0;
134EmptyThirtyTwo emptyThirtyTwo;
135EmptySixteen emptySixteen;
136EmptyEight emptyEight(0);
137
138class BitUnionData : public testing::Test {
139  protected:
140    SixtyFour sixtyFour;
141    Split split;
142
143    void SetUp() override { sixtyFour = 0; split = 0; }
144
145    template <typename T>
146    uint64_t templatedFunction(T) { return 0; }
147
148    template <typename T>
149    uint64_t
150    templatedFunction(BitUnionType<T> u)
151    {
152        BitUnionBaseType<T> b = u;
153        return b;
154    }
155};
156
157TEST_F(BitUnionData, NormalBitfield)
158{
159    EXPECT_EQ(sixtyFour.byte5, 0);
160    sixtyFour.byte5 = 0xff;
161    EXPECT_EQ(sixtyFour, 0xff00000000);
162    sixtyFour.byte5 = 0xfff;
163    EXPECT_EQ(sixtyFour, 0xff00000000);
164    EXPECT_EQ(sixtyFour.byte5, 0xff);
165}
166
167TEST_F(BitUnionData, SingleBitfield)
168{
169    EXPECT_EQ(sixtyFour.bit2, 0);
170    sixtyFour.bit2 = 0x1;
171    EXPECT_EQ(sixtyFour, 0x4);
172    EXPECT_EQ(sixtyFour.bit2, 0x1);
173}
174
175TEST_F(BitUnionData, ReadOnlyBitfield)
176{
177    EXPECT_EQ(sixtyFour.byte5RO, 0);
178    sixtyFour.byte5 = 0xff;
179    EXPECT_EQ(sixtyFour.byte5RO, 0xff);
180}
181
182TEST_F(BitUnionData, WriteOnlyBitfield)
183{
184    sixtyFour.byte5WO = 0xff;
185    EXPECT_EQ(sixtyFour, 0xff00000000);
186}
187
188TEST_F(BitUnionData, SubBitUnions)
189{
190    EXPECT_EQ(sixtyFour.byte6.bit41, 0);
191    sixtyFour.byte6 = 0x2;
192    EXPECT_EQ(sixtyFour.byte6.bit41, 1);
193    sixtyFour.byte6.bits43To42 = 0x3;
194    EXPECT_EQ(sixtyFour.byte6, 0xe);
195    sixtyFour.byte6 = 0xff;
196    sixtyFour.byte6.bit41 = 0;
197    EXPECT_EQ(sixtyFour, 0xfd0000000000);
198}
199
200TEST_F(BitUnionData, SignedBitfields)
201{
202    sixtyFour.byte6 = 0xff;
203    EXPECT_EQ(sixtyFour.byte6Signed, -1);
204    EXPECT_EQ(sixtyFour.byte6SignedRO, -1);
205    sixtyFour.byte6SignedWO = 0;
206    EXPECT_EQ(sixtyFour.byte6Signed, 0);
207    EXPECT_EQ(sixtyFour.byte6SignedRO, 0);
208    EXPECT_EQ(sixtyFour.byte6, 0);
209}
210
211TEST_F(BitUnionData, InsideStruct)
212{
213    ContainingStruct containing;
214    containing.contained = 0;
215    containing.contained.topNibble = 0xd;
216    EXPECT_EQ(containing.contained, 0xd000000000000000);
217}
218
219TEST_F(BitUnionData, InsideFunction)
220{
221    EXPECT_EQ(containingFunc(0xfffff, 0), 0xe7fff);
222}
223
224TEST_F(BitUnionData, BitfieldToBitfieldAssignment)
225{
226    SixtyFour otherSixtyFour = 0;
227    sixtyFour.bit2 = 1;
228    otherSixtyFour.byte6.bit41 = sixtyFour.bit2;
229    EXPECT_EQ(otherSixtyFour, 0x20000000000);
230    otherSixtyFour.bit2 = sixtyFour.bit2;
231    EXPECT_EQ(otherSixtyFour, 0x20000000004);
232}
233
234TEST_F(BitUnionData, Operators)
235{
236    SixtyFour otherSixtyFour = 0x4;
237    sixtyFour = otherSixtyFour;
238    EXPECT_EQ(sixtyFour, 0x4);
239    sixtyFour = 0;
240    EXPECT_TRUE(sixtyFour < otherSixtyFour);
241    EXPECT_TRUE(otherSixtyFour > sixtyFour);
242    EXPECT_TRUE(sixtyFour != otherSixtyFour);
243    sixtyFour = otherSixtyFour;
244    EXPECT_TRUE(sixtyFour == otherSixtyFour);
245}
246
247TEST_F(BitUnionData, Custom)
248{
249    EXPECT_EQ(split, 0);
250    split.split = 0xfff;
251    EXPECT_EQ(split, 0xf0f0);
252    EXPECT_EQ((uint64_t)split.split, 0xff);
253}
254
255TEST_F(BitUnionData, Templating)
256{
257    sixtyFour = 0xff;
258    EXPECT_EQ(templatedFunction(sixtyFour), 0xff);
259    EXPECT_EQ(templatedFunction((uint64_t)sixtyFour), 0);
260
261    BitUnion(uint64_t, Dummy64)
262    EndBitUnion(Dummy64);
263
264    BitUnion(uint32_t, Dummy32)
265    EndBitUnion(Dummy32);
266
267    bool is64;
268    is64 = std::is_same<BitUnionBaseType<Dummy64>, uint64_t>::value;
269    EXPECT_TRUE(is64);
270    is64 = std::is_same<BitUnionBaseType<Dummy32>, uint64_t>::value;
271    EXPECT_FALSE(is64);
272}
273
274TEST_F(BitUnionData, Output)
275{
276    sixtyFour = 1234567812345678;
277    std::stringstream ss;
278    ss << sixtyFour;
279    EXPECT_EQ(ss.str(), "1234567812345678");
280    ss.str("");
281
282    EmptyEight eight = 65;
283    ss << eight;
284    EXPECT_EQ(ss.str(), "65");
285    ss.str("");
286}
287