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1 //===- llvm/unittest/ADT/PointerIntPairTest.cpp - Unit tests --------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "gtest/gtest.h"
11 #include "llvm/ADT/PointerIntPair.h"
12 #include <limits>
13 using namespace llvm;
14 
15 namespace {
16 
TEST(PointerIntPairTest,GetSet)17 TEST(PointerIntPairTest, GetSet) {
18   struct S {
19     int i;
20   };
21   S s;
22 
23   PointerIntPair<S *, 2> Pair(&s, 1U);
24   EXPECT_EQ(&s, Pair.getPointer());
25   EXPECT_EQ(1U, Pair.getInt());
26 
27   Pair.setInt(2);
28   EXPECT_EQ(&s, Pair.getPointer());
29   EXPECT_EQ(2U, Pair.getInt());
30 
31   Pair.setPointer(nullptr);
32   EXPECT_EQ(nullptr, Pair.getPointer());
33   EXPECT_EQ(2U, Pair.getInt());
34 
35   Pair.setPointerAndInt(&s, 3U);
36   EXPECT_EQ(&s, Pair.getPointer());
37   EXPECT_EQ(3U, Pair.getInt());
38 
39   // Make sure that we can perform all of our operations on enum classes.
40   //
41   // The concern is that enum classes are only explicitly convertible to
42   // integers. This means that if we assume in PointerIntPair this, a
43   // compilation error will result. This group of tests exercises the enum class
44   // code to make sure that we do not run into such issues in the future.
45   enum class E : unsigned {
46     Case1,
47     Case2,
48     Case3,
49   };
50   PointerIntPair<S *, 2, E> Pair2(&s, E::Case1);
51   EXPECT_EQ(&s, Pair2.getPointer());
52   EXPECT_EQ(E::Case1, Pair2.getInt());
53 
54   Pair2.setInt(E::Case2);
55   EXPECT_EQ(&s, Pair2.getPointer());
56   EXPECT_EQ(E::Case2, Pair2.getInt());
57 
58   Pair2.setPointer(nullptr);
59   EXPECT_EQ(nullptr, Pair2.getPointer());
60   EXPECT_EQ(E::Case2, Pair2.getInt());
61 
62   Pair2.setPointerAndInt(&s, E::Case3);
63   EXPECT_EQ(&s, Pair2.getPointer());
64   EXPECT_EQ(E::Case3, Pair2.getInt());
65 }
66 
TEST(PointerIntPairTest,DefaultInitialize)67 TEST(PointerIntPairTest, DefaultInitialize) {
68   PointerIntPair<float *, 2> Pair;
69   EXPECT_EQ(nullptr, Pair.getPointer());
70   EXPECT_EQ(0U, Pair.getInt());
71 }
72 
TEST(PointerIntPairTest,ManyUnusedBits)73 TEST(PointerIntPairTest, ManyUnusedBits) {
74   // In real code this would be a word-sized integer limited to 31 bits.
75   struct Fixnum31 {
76     uintptr_t Value;
77   };
78   class FixnumPointerTraits {
79   public:
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     enum { NumLowBitsAvailable = std::numeric_limits<uintptr_t>::digits - 31 };
88   };
89 
90   PointerIntPair<Fixnum31, 1, bool, FixnumPointerTraits> pair;
91   EXPECT_EQ((uintptr_t)0, pair.getPointer().Value);
92   EXPECT_FALSE(pair.getInt());
93 
94   pair.setPointerAndInt({ 0x7FFFFFFF }, true );
95   EXPECT_EQ((uintptr_t)0x7FFFFFFF, pair.getPointer().Value);
96   EXPECT_TRUE(pair.getInt());
97 
98   EXPECT_EQ(FixnumPointerTraits::NumLowBitsAvailable - 1,
99             PointerLikeTypeTraits<decltype(pair)>::NumLowBitsAvailable);
100 }
101 
102 } // end anonymous namespace
103