llvm-6502/unittests/ADT/PointerIntPairTest.cpp
Jordan Rose bc3b24269e [ADT] Update PointerIntPair to handle pointer types with more than 31 bits free.
Previously, the assertions in PointerIntPair would try to calculate the value
(1 << NumLowBitsAvailable); the inferred type here is 'int', so if there were
more than 31 bits available we'd get a shift overflow.

Also, add a rudimentary unit test file for PointerIntPair.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203273 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-07 19:19:56 +00:00

75 lines
2.2 KiB
C++

//===- llvm/unittest/ADT/PointerIntPairTest.cpp - Unit tests --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "gtest/gtest.h"
#include "llvm/ADT/PointerIntPair.h"
#include <limits>
using namespace llvm;
namespace {
// Test fixture
class PointerIntPairTest : public testing::Test {
};
TEST_F(PointerIntPairTest, GetSet) {
PointerIntPair<PointerIntPairTest *, 2> Pair{this, 1U};
EXPECT_EQ(this, Pair.getPointer());
EXPECT_EQ(1U, Pair.getInt());
Pair.setInt(2);
EXPECT_EQ(this, Pair.getPointer());
EXPECT_EQ(2U, Pair.getInt());
Pair.setPointer(nullptr);
EXPECT_EQ(nullptr, Pair.getPointer());
EXPECT_EQ(2U, Pair.getInt());
Pair.setPointerAndInt(this, 3U);
EXPECT_EQ(this, Pair.getPointer());
EXPECT_EQ(3U, Pair.getInt());
}
TEST_F(PointerIntPairTest, DefaultInitialize) {
PointerIntPair<PointerIntPairTest *, 2> Pair;
EXPECT_EQ(nullptr, Pair.getPointer());
EXPECT_EQ(0U, Pair.getInt());
}
TEST_F(PointerIntPairTest, ManyUnusedBits) {
// In real code this would be a word-sized integer limited to 31 bits.
struct Fixnum31 {
uintptr_t Value;
};
class FixnumPointerTraits {
public:
static inline void *getAsVoidPointer(Fixnum31 Num) {
return reinterpret_cast<void *>(Num.Value << NumLowBitsAvailable);
}
static inline Fixnum31 getFromVoidPointer(void *P) {
// In real code this would assert that the value is in range.
return { reinterpret_cast<uintptr_t>(P) >> NumLowBitsAvailable };
}
enum { NumLowBitsAvailable = std::numeric_limits<uintptr_t>::digits - 31 };
};
PointerIntPair<Fixnum31, 1, bool, FixnumPointerTraits> pair;
EXPECT_EQ((uintptr_t)0, pair.getPointer().Value);
EXPECT_EQ(false, pair.getInt());
pair.setPointerAndInt({ 0x7FFFFFFF }, true );
EXPECT_EQ((uintptr_t)0x7FFFFFFF, pair.getPointer().Value);
EXPECT_EQ(true, pair.getInt());
EXPECT_EQ(FixnumPointerTraits::NumLowBitsAvailable - 1,
PointerLikeTypeTraits<decltype(pair)>::NumLowBitsAvailable);
}
} // end anonymous namespace