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 
17 // Test fixture
18 class PointerIntPairTest : public testing::Test {
19 };
20 
TEST_F(PointerIntPairTest,GetSet)21 TEST_F(PointerIntPairTest, GetSet) {
22   PointerIntPair<PointerIntPairTest *, 2> Pair(this, 1U);
23   EXPECT_EQ(this, Pair.getPointer());
24   EXPECT_EQ(1U, Pair.getInt());
25 
26   Pair.setInt(2);
27   EXPECT_EQ(this, 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(this, 3U);
35   EXPECT_EQ(this, Pair.getPointer());
36   EXPECT_EQ(3U, Pair.getInt());
37 }
38 
TEST_F(PointerIntPairTest,DefaultInitialize)39 TEST_F(PointerIntPairTest, DefaultInitialize) {
40   PointerIntPair<PointerIntPairTest *, 2> Pair;
41   EXPECT_EQ(nullptr, Pair.getPointer());
42   EXPECT_EQ(0U, Pair.getInt());
43 }
44 
TEST_F(PointerIntPairTest,ManyUnusedBits)45 TEST_F(PointerIntPairTest, ManyUnusedBits) {
46   // In real code this would be a word-sized integer limited to 31 bits.
47   struct Fixnum31 {
48     uintptr_t Value;
49   };
50   class FixnumPointerTraits {
51   public:
52     static inline void *getAsVoidPointer(Fixnum31 Num) {
53       return reinterpret_cast<void *>(Num.Value << NumLowBitsAvailable);
54     }
55     static inline Fixnum31 getFromVoidPointer(void *P) {
56       // In real code this would assert that the value is in range.
57       return { reinterpret_cast<uintptr_t>(P) >> NumLowBitsAvailable };
58     }
59     enum { NumLowBitsAvailable = std::numeric_limits<uintptr_t>::digits - 31 };
60   };
61 
62   PointerIntPair<Fixnum31, 1, bool, FixnumPointerTraits> pair;
63   EXPECT_EQ((uintptr_t)0, pair.getPointer().Value);
64   EXPECT_FALSE(pair.getInt());
65 
66   pair.setPointerAndInt({ 0x7FFFFFFF }, true );
67   EXPECT_EQ((uintptr_t)0x7FFFFFFF, pair.getPointer().Value);
68   EXPECT_TRUE(pair.getInt());
69 
70   EXPECT_EQ(FixnumPointerTraits::NumLowBitsAvailable - 1,
71             PointerLikeTypeTraits<decltype(pair)>::NumLowBitsAvailable);
72 }
73 
74 } // end anonymous namespace
75