1 //===- llvm/unittest/ADT/PointerIntPairTest.cpp - Unit tests --------------===//
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 #include "llvm/ADT/PointerIntPair.h"
10 #include "gtest/gtest.h"
11 #include <limits>
12 using namespace llvm;
13
14 namespace {
15
TEST(PointerIntPairTest,GetSet)16 TEST(PointerIntPairTest, GetSet) {
17 struct S {
18 int i;
19 };
20 S s;
21
22 PointerIntPair<S *, 2> Pair(&s, 1U);
23 EXPECT_EQ(&s, Pair.getPointer());
24 EXPECT_EQ(1U, Pair.getInt());
25
26 Pair.setInt(2);
27 EXPECT_EQ(&s, Pair.getPointer());
28 EXPECT_EQ(2U, Pair.getInt());
29
30 Pair.setPointer(nullptr);
31 EXPECT_EQ(nullptr, Pair.getPointer());
32 EXPECT_EQ(2U, Pair.getInt());
33
34 Pair.setPointerAndInt(&s, 3U);
35 EXPECT_EQ(&s, Pair.getPointer());
36 EXPECT_EQ(3U, Pair.getInt());
37
38 // Make sure that we can perform all of our operations on enum classes.
39 //
40 // The concern is that enum classes are only explicitly convertible to
41 // integers. This means that if we assume in PointerIntPair this, a
42 // compilation error will result. This group of tests exercises the enum class
43 // code to make sure that we do not run into such issues in the future.
44 enum class E : unsigned {
45 Case1,
46 Case2,
47 Case3,
48 };
49 PointerIntPair<S *, 2, E> Pair2(&s, E::Case1);
50 EXPECT_EQ(&s, Pair2.getPointer());
51 EXPECT_EQ(E::Case1, Pair2.getInt());
52
53 Pair2.setInt(E::Case2);
54 EXPECT_EQ(&s, Pair2.getPointer());
55 EXPECT_EQ(E::Case2, Pair2.getInt());
56
57 Pair2.setPointer(nullptr);
58 EXPECT_EQ(nullptr, Pair2.getPointer());
59 EXPECT_EQ(E::Case2, Pair2.getInt());
60
61 Pair2.setPointerAndInt(&s, E::Case3);
62 EXPECT_EQ(&s, Pair2.getPointer());
63 EXPECT_EQ(E::Case3, Pair2.getInt());
64
65 auto [Pointer2, Int2] = Pair2;
66 EXPECT_EQ(Pair2.getPointer(), Pointer2);
67 EXPECT_EQ(Pair2.getInt(), Int2);
68
69 static_assert(std::is_trivially_copyable_v<PointerIntPair<S *, 2, E>>,
70 "trivially copyable");
71 }
72
TEST(PointerIntPairTest,DefaultInitialize)73 TEST(PointerIntPairTest, DefaultInitialize) {
74 PointerIntPair<float *, 2> Pair;
75 EXPECT_EQ(nullptr, Pair.getPointer());
76 EXPECT_EQ(0U, Pair.getInt());
77 }
78
79 // In real code this would be a word-sized integer limited to 31 bits.
80 struct Fixnum31 {
81 uintptr_t Value;
82 };
83 struct FixnumPointerTraits {
getAsVoidPointer__anon65e4db1f0111::FixnumPointerTraits84 static inline void *getAsVoidPointer(Fixnum31 Num) {
85 return reinterpret_cast<void *>(Num.Value << NumLowBitsAvailable);
86 }
getFromVoidPointer__anon65e4db1f0111::FixnumPointerTraits87 static inline Fixnum31 getFromVoidPointer(void *P) {
88 // In real code this would assert that the value is in range.
89 return {reinterpret_cast<uintptr_t>(P) >> NumLowBitsAvailable};
90 }
91 static constexpr int NumLowBitsAvailable =
92 std::numeric_limits<uintptr_t>::digits - 31;
93 };
TEST(PointerIntPairTest,ManyUnusedBits)94 TEST(PointerIntPairTest, ManyUnusedBits) {
95
96 PointerIntPair<Fixnum31, 1, bool, FixnumPointerTraits> pair;
97 EXPECT_EQ((uintptr_t)0, pair.getPointer().Value);
98 EXPECT_FALSE(pair.getInt());
99
100 pair.setPointerAndInt({ 0x7FFFFFFF }, true );
101 EXPECT_EQ((uintptr_t)0x7FFFFFFF, pair.getPointer().Value);
102 EXPECT_TRUE(pair.getInt());
103
104 EXPECT_EQ(FixnumPointerTraits::NumLowBitsAvailable - 1,
105 (int)PointerLikeTypeTraits<decltype(pair)>::NumLowBitsAvailable);
106
107 static_assert(std::is_trivially_copyable_v<
108 PointerIntPair<Fixnum31, 1, bool, FixnumPointerTraits>>,
109 "trivially copyable");
110 }
111
TEST(PointerIntPairTest,TypePunning)112 TEST(PointerIntPairTest, TypePunning) {
113 int I = 0;
114 int *IntPtr = &I;
115
116 int **IntPtrBegin = &IntPtr;
117 int **IntPtrEnd = IntPtrBegin + 1;
118
119 PointerIntPair<int *, 1> Pair;
120 int **PairAddr = Pair.getAddrOfPointer();
121
122 while (IntPtrBegin != IntPtrEnd) {
123 *PairAddr = *IntPtrBegin;
124 ++PairAddr;
125 ++IntPtrBegin;
126 }
127 EXPECT_EQ(Pair.getPointer(), IntPtr);
128 }
129
130 } // end anonymous namespace
131