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 
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   static_assert(std::is_trivially_copyable<PointerIntPair<S *, 2, E>>::value,
66                 "trivially copyable");
67 }
68 
69 TEST(PointerIntPairTest, DefaultInitialize) {
70   PointerIntPair<float *, 2> Pair;
71   EXPECT_EQ(nullptr, Pair.getPointer());
72   EXPECT_EQ(0U, Pair.getInt());
73 }
74 
75 // In real code this would be a word-sized integer limited to 31 bits.
76 struct Fixnum31 {
77   uintptr_t Value;
78 };
79 struct FixnumPointerTraits {
80   static inline void *getAsVoidPointer(Fixnum31 Num) {
81     return reinterpret_cast<void *>(Num.Value << NumLowBitsAvailable);
82   }
83   static inline Fixnum31 getFromVoidPointer(void *P) {
84     // In real code this would assert that the value is in range.
85     return {reinterpret_cast<uintptr_t>(P) >> NumLowBitsAvailable};
86   }
87   static constexpr int NumLowBitsAvailable =
88       std::numeric_limits<uintptr_t>::digits - 31;
89 };
90 TEST(PointerIntPairTest, ManyUnusedBits) {
91 
92   PointerIntPair<Fixnum31, 1, bool, FixnumPointerTraits> pair;
93   EXPECT_EQ((uintptr_t)0, pair.getPointer().Value);
94   EXPECT_FALSE(pair.getInt());
95 
96   pair.setPointerAndInt({ 0x7FFFFFFF }, true );
97   EXPECT_EQ((uintptr_t)0x7FFFFFFF, pair.getPointer().Value);
98   EXPECT_TRUE(pair.getInt());
99 
100   EXPECT_EQ(FixnumPointerTraits::NumLowBitsAvailable - 1,
101             (int)PointerLikeTypeTraits<decltype(pair)>::NumLowBitsAvailable);
102 
103   static_assert(
104       std::is_trivially_copyable<
105           PointerIntPair<Fixnum31, 1, bool, FixnumPointerTraits>>::value,
106       "trivially copyable");
107 }
108 
109 } // end anonymous namespace
110