[PDB] General improvements to Stream library.

This adds various new functionality and cleanup surrounding the
use of the Stream library.  Major changes include:

* Renaming of all classes for more consistency / meaningfulness
* Addition of some new methods for reading multiple values at once.
* Full suite of unit tests for reader / writer functionality.
* Full set of doxygen comments for all classes.
* Streams now store their own endianness.
* Fixed some bugs in a few of the classes that were discovered
  by the unit tests.

llvm-svn: 296215

1 files changed, 764 insertions, 0 deletions

diff --git a/llvm/unittests/DebugInfo/PDB/BinaryStreamTest.cpp b/llvm/unittests/DebugInfo/PDB/BinaryStreamTest.cpp
new file mode 100644
index 00000000000..4c38fa48fe6
--- /dev/null
+++ b/llvm/unittests/DebugInfo/PDB/BinaryStreamTest.cpp
@@ -0,0 +1,764 @@
+//===- llvm/unittest/Support/BinaryStreamTest.cpp -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/MSF/BinaryByteStream.h"
+#include "llvm/DebugInfo/MSF/BinaryItemStream.h"
+#include "llvm/DebugInfo/MSF/BinaryStreamArray.h"
+#include "llvm/DebugInfo/MSF/BinaryStreamReader.h"
+#include "llvm/DebugInfo/MSF/BinaryStreamRef.h"
+#include "llvm/DebugInfo/MSF/BinaryStreamWriter.h"
+#include "gtest/gtest.h"
+
+#include <unordered_map>
+
+using namespace llvm;
+using namespace llvm::support;
+
+#define EXPECT_NO_ERROR(Err)                                                   \
+  {                                                                            \
+    auto E = Err;                                                              \
+    EXPECT_FALSE(static_cast<bool>(E));                                        \
+    if (E)                                                                     \
+      consumeError(std::move(E));                                              \
+  }
+
+#define ASSERT_NO_ERROR(Err)                                                   \
+  {                                                                            \
+    auto E = Err;                                                              \
+    ASSERT_FALSE(static_cast<bool>(E));                                        \
+    if (E)                                                                     \
+      consumeError(std::move(E));                                              \
+  }
+
+#define EXPECT_ERROR(Err)                                                      \
+  {                                                                            \
+    auto E = Err;                                                              \
+    EXPECT_TRUE(static_cast<bool>(E));                                         \
+    if (E)                                                                     \
+      consumeError(std::move(E));                                              \
+  }
+
+namespace {
+
+class DiscontiguousStream : public WritableBinaryStream {
+public:
+  explicit DiscontiguousStream(uint32_t Size = 0) : PartitionIndex(Size / 2) {
+    Data.resize(Size);
+  }
+
+  endianness getEndian() const override { return little; }
+
+  Error readBytes(uint32_t Offset, uint32_t Size,
+                  ArrayRef<uint8_t> &Buffer) override {
+    if (Offset + Size > Data.size())
+      return errorCodeToError(make_error_code(std::errc::no_buffer_space));
+    uint32_t S = startIndex(Offset);
+    auto Ref = makeArrayRef(Data).drop_front(S);
+    if (Ref.size() >= Size) {
+      Buffer = Ref.take_front(Size);
+      return Error::success();
+    }
+
+    uint32_t BytesLeft = Size - Ref.size();
+    uint8_t *Ptr = Allocator.Allocate<uint8_t>(Size);
+    ::memcpy(Ptr, Ref.data(), Ref.size());
+    ::memcpy(Ptr + Ref.size(), Data.data(), BytesLeft);
+    Buffer = makeArrayRef<uint8_t>(Ptr, Size);
+    return Error::success();
+  }
+
+  Error readLongestContiguousChunk(uint32_t Offset,
+                                   ArrayRef<uint8_t> &Buffer) override {
+    if (Offset >= Data.size())
+      return errorCodeToError(make_error_code(std::errc::no_buffer_space));
+    uint32_t S = startIndex(Offset);
+    Buffer = makeArrayRef(Data).drop_front(S);
+    return Error::success();
+  }
+
+  uint32_t getLength() override { return Data.size(); }
+
+  Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> SrcData) override {
+    if (Offset + SrcData.size() > Data.size())
+      return errorCodeToError(make_error_code(std::errc::no_buffer_space));
+    if (SrcData.empty())
+      return Error::success();
+
+    uint32_t S = startIndex(Offset);
+    MutableArrayRef<uint8_t> Ref(Data);
+    Ref = Ref.drop_front(S);
+    if (Ref.size() >= SrcData.size()) {
+      ::memcpy(Ref.data(), SrcData.data(), SrcData.size());
+      return Error::success();
+    }
+
+    uint32_t BytesLeft = SrcData.size() - Ref.size();
+    ::memcpy(Ref.data(), SrcData.data(), Ref.size());
+    ::memcpy(&Data[0], SrcData.data() + Ref.size(), BytesLeft);
+    return Error::success();
+  }
+  Error commit() override { return Error::success(); }
+
+private:
+  uint32_t startIndex(uint32_t Offset) const {
+    return (Offset + PartitionIndex) % Data.size();
+  }
+
+  uint32_t endIndex(uint32_t Offset, uint32_t Size) const {
+    return (startIndex(Offset) + Size - 1) % Data.size();
+  }
+
+  uint32_t PartitionIndex = 0;
+  // Buffer is organized like this:
+  // -------------------------------------------------
+  // | N/2 | N/2+1 | ... | N-1 | 0 | 1 | ... | N-2-1 |
+  // -------------------------------------------------
+  // So reads from the beginning actually come from the middle.
+  std::vector<uint8_t> Data;
+  BumpPtrAllocator Allocator;
+};
+
+class BinaryStreamTest : public testing::Test {
+public:
+  BinaryStreamTest() {}
+
+  void SetUp() override {
+    InputData.clear();
+    OutputData.clear();
+    InputByteStream = BinaryByteStream();
+    InputBrokenStream = DiscontiguousStream();
+    OutputByteStream = MutableBinaryByteStream();
+    OutputBrokenStream = DiscontiguousStream();
+  }
+
+protected:
+  void initialize(ArrayRef<uint8_t> Input, uint32_t OutputSize) {
+    InputData = Input;
+
+    InputByteStream = BinaryByteStream(InputData, little);
+    InputBrokenStream = DiscontiguousStream(InputData.size());
+    consumeError(InputBrokenStream.writeBytes(0, Input));
+
+    OutputData.resize(OutputSize);
+    OutputByteStream = MutableBinaryByteStream(OutputData, little);
+    OutputBrokenStream = DiscontiguousStream(OutputSize);
+
+    InputStreams.push_back(&InputByteStream);
+    InputStreams.push_back(&InputBrokenStream);
+    OutputStreams.push_back(&OutputByteStream);
+    OutputStreams.push_back(&OutputBrokenStream);
+  }
+
+  void initialize(uint32_t OutputSize) {
+    OutputData.resize(OutputSize);
+    OutputByteStream = MutableBinaryByteStream(OutputData, little);
+    OutputBrokenStream = DiscontiguousStream(OutputSize);
+    OutputStreams.push_back(&OutputByteStream);
+    OutputStreams.push_back(&OutputBrokenStream);
+
+    InputByteStream = BinaryByteStream(OutputData, little);
+    InputBrokenStream = DiscontiguousStream(OutputData.size());
+  }
+
+  std::vector<uint8_t> InputData;
+  std::vector<uint8_t> OutputData;
+
+  BinaryByteStream InputByteStream;
+  DiscontiguousStream InputBrokenStream;
+
+  MutableBinaryByteStream OutputByteStream;
+  DiscontiguousStream OutputBrokenStream;
+
+  std::vector<BinaryStream *> InputStreams;
+  std::vector<WritableBinaryStream *> OutputStreams;
+};
+
+// Tests that a we can read from a BinaryByteStream without a StreamReader.
+TEST_F(BinaryStreamTest, BinaryByteStreamProperties) {
+  std::vector<uint8_t> InputData = {1, 2, 3, 4, 5};
+  initialize(InputData, InputData.size());
+
+  for (auto Stream : InputStreams) {
+    ArrayRef<uint8_t> Buffer;
+
+    // 1. If the read fits it should work.
+    ASSERT_EQ(InputData.size(), Stream->getLength());
+    ASSERT_NO_ERROR(Stream->readBytes(2, 1, Buffer));
+    EXPECT_EQ(makeArrayRef(InputData).slice(2, 1), Buffer);
+    ASSERT_NO_ERROR(Stream->readBytes(0, 4, Buffer));
+    EXPECT_EQ(makeArrayRef(InputData).slice(0, 4), Buffer);
+
+    // 2. Reading past the bounds of the input should fail.
+    EXPECT_ERROR(Stream->readBytes(4, 2, Buffer));
+  }
+}
+
+// Test that we can write to a BinaryStream without a StreamWriter.
+TEST_F(BinaryStreamTest, MutableBinaryByteStreamProperties) {
+  std::vector<uint8_t> InputData = {'T', 'e', 's', 't', '\0'};
+  initialize(InputData, InputData.size());
+  ASSERT_EQ(2U, InputStreams.size());
+  ASSERT_EQ(2U, OutputStreams.size());
+
+  // For every combination of input stream and output stream.
+  for (auto IS : InputStreams) {
+    MutableArrayRef<uint8_t> Buffer;
+    ASSERT_EQ(InputData.size(), IS->getLength());
+
+    for (auto OS : OutputStreams) {
+
+      // 1. Try two reads that are supposed to work.  One from offset 0, and one
+      // from the middle.
+      uint32_t Offsets[] = {0, 3};
+      for (auto Offset : Offsets) {
+        uint32_t ExpectedSize = IS->getLength() - Offset;
+
+        // Read everything from Offset until the end of the input data.
+        ArrayRef<uint8_t> Data;
+        ASSERT_NO_ERROR(IS->readBytes(Offset, ExpectedSize, Data));
+        ASSERT_EQ(ExpectedSize, Data.size());
+
+        // Then write it to the destination.
+        ASSERT_NO_ERROR(OS->writeBytes(0, Data));
+
+        // Then we read back what we wrote, it should match the corresponding
+        // slice
+        // of the original input data.
+        ArrayRef<uint8_t> Data2;
+        ASSERT_NO_ERROR(OS->readBytes(Offset, ExpectedSize, Data2));
+        EXPECT_EQ(makeArrayRef(InputData).drop_front(Offset), Data2);
+      }
+
+      std::vector<uint8_t> BigData = {0, 1, 2, 3, 4};
+      // 2. If the write is too big, it should fail.
+      EXPECT_ERROR(OS->writeBytes(3, BigData));
+    }
+  }
+}
+
+// Test that FixedStreamArray works correctly.
+TEST_F(BinaryStreamTest, FixedStreamArray) {
+  std::vector<uint32_t> Ints = {90823, 12908, 109823, 209823};
+  ArrayRef<uint8_t> IntBytes(reinterpret_cast<uint8_t *>(Ints.data()),
+                             Ints.size() * sizeof(uint32_t));
+
+  initialize(IntBytes, 0);
+  ASSERT_EQ(2U, InputStreams.size());
+
+  for (auto IS : InputStreams) {
+    MutableArrayRef<uint8_t> Buffer;
+    ASSERT_EQ(InputData.size(), IS->getLength());
+
+    FixedStreamArray<uint32_t> Array(*IS);
+    auto Iter = Array.begin();
+    ASSERT_EQ(Ints[0], *Iter++);
+    ASSERT_EQ(Ints[1], *Iter++);
+    ASSERT_EQ(Ints[2], *Iter++);
+    ASSERT_EQ(Ints[3], *Iter++);
+    ASSERT_EQ(Array.end(), Iter);
+  }
+}
+
+// Test that VarStreamArray works correctly.
+TEST_F(BinaryStreamTest, VarStreamArray) {
+  StringLiteral Strings("1. Test2. Longer Test3. Really Long Test4. Super "
+                        "Extra Longest Test Of All");
+  ArrayRef<uint8_t> StringBytes(
+      reinterpret_cast<const uint8_t *>(Strings.data()), Strings.size());
+  initialize(StringBytes, 0);
+
+  struct StringExtractor {
+  public:
+    Error operator()(BinaryStreamRef Stream, uint32_t &Len, StringRef &Item) {
+      if (Index == 0)
+        Len = strlen("1. Test");
+      else if (Index == 1)
+        Len = strlen("2. Longer Test");
+      else if (Index == 2)
+        Len = strlen("3. Really Long Test");
+      else
+        Len = strlen("4. Super Extra Longest Test Of All");
+      ArrayRef<uint8_t> Bytes;
+      if (auto EC = Stream.readBytes(0, Len, Bytes))
+        return EC;
+      Item =
+          StringRef(reinterpret_cast<const char *>(Bytes.data()), Bytes.size());
+      ++Index;
+      return Error::success();
+    }
+
+  private:
+    uint32_t Index = 0;
+  };
+
+  for (auto IS : InputStreams) {
+    VarStreamArray<StringRef, StringExtractor> Array(*IS);
+    auto Iter = Array.begin();
+    ASSERT_EQ("1. Test", *Iter++);
+    ASSERT_EQ("2. Longer Test", *Iter++);
+    ASSERT_EQ("3. Really Long Test", *Iter++);
+    ASSERT_EQ("4. Super Extra Longest Test Of All", *Iter++);
+    ASSERT_EQ(Array.end(), Iter);
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamReaderBounds) {
+  std::vector<uint8_t> Bytes;
+
+  initialize(Bytes, 0);
+  for (auto IS : InputStreams) {
+    StringRef S;
+    BinaryStreamReader Reader(*IS);
+    EXPECT_EQ(0U, Reader.bytesRemaining());
+    EXPECT_ERROR(Reader.readFixedString(S, 1));
+  }
+
+  Bytes.resize(5);
+  initialize(Bytes, 0);
+  for (auto IS : InputStreams) {
+    StringRef S;
+    BinaryStreamReader Reader(*IS);
+    EXPECT_EQ(Bytes.size(), Reader.bytesRemaining());
+    EXPECT_NO_ERROR(Reader.readFixedString(S, 5));
+    EXPECT_ERROR(Reader.readFixedString(S, 6));
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamReaderIntegers) {
+  support::ulittle64_t Little{908234};
+  support::ubig32_t Big{28907823};
+  short NS = 2897;
+  int NI = -89723;
+  unsigned long NUL = 902309023UL;
+  constexpr uint32_t Size =
+      sizeof(Little) + sizeof(Big) + sizeof(NS) + sizeof(NI) + sizeof(NUL);
+  std::vector<uint8_t> Bytes(Size);
+  uint8_t *Ptr = &Bytes[0];
+  memcpy(Ptr, &Little, sizeof(Little));
+  Ptr += sizeof(Little);
+  memcpy(Ptr, &Big, sizeof(Big));
+  Ptr += sizeof(Big);
+  memcpy(Ptr, &NS, sizeof(NS));
+  Ptr += sizeof(NS);
+  memcpy(Ptr, &NI, sizeof(NI));
+  Ptr += sizeof(NI);
+  memcpy(Ptr, &NUL, sizeof(NUL));
+  Ptr += sizeof(NUL);
+
+  initialize(Bytes, 0);
+  for (auto IS : InputStreams) {
+    const support::ulittle64_t *Little2;
+    const support::ubig32_t *Big2;
+    short NS2;
+    int NI2;
+    unsigned long NUL2;
+
+    // 1. Reading fields individually.
+    BinaryStreamReader Reader(*IS);
+    ASSERT_NO_ERROR(Reader.readObject(Little2));
+    ASSERT_NO_ERROR(Reader.readObject(Big2));
+    ASSERT_NO_ERROR(Reader.readInteger(NS2));
+    ASSERT_NO_ERROR(Reader.readInteger(NI2));
+    ASSERT_NO_ERROR(Reader.readInteger(NUL2));
+    ASSERT_EQ(0U, Reader.bytesRemaining());
+
+    EXPECT_EQ(Little, *Little2);
+    EXPECT_EQ(Big, *Big2);
+    EXPECT_EQ(NS, NS2);
+    EXPECT_EQ(NI, NI2);
+    EXPECT_EQ(NUL, NUL2);
+
+    // 2. Reading with explicit endianness.
+    Reader.setOffset(0);
+    const ulittle64_t *Little3;
+    const ubig32_t *Big3;
+    ASSERT_NO_ERROR(Reader.readObject(Little3));
+    ASSERT_NO_ERROR(Reader.readObject(Big3));
+    EXPECT_EQ(Little, *Little3);
+    EXPECT_EQ(Big, *Big3);
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamReaderIntegerArray) {
+  // 1. Arrays of integers
+  std::vector<int> Ints = {1, 2, 3, 4, 5};
+  ArrayRef<uint8_t> IntBytes(reinterpret_cast<uint8_t *>(&Ints[0]),
+                             Ints.size() * sizeof(int));
+  initialize(IntBytes, 0);
+  for (auto IS : InputStreams) {
+    BinaryStreamReader Reader(*IS);
+    ArrayRef<int> IntsRef;
+    ASSERT_NO_ERROR(Reader.readArray(IntsRef, Ints.size()));
+    ASSERT_EQ(0U, Reader.bytesRemaining());
+    EXPECT_EQ(makeArrayRef(Ints), IntsRef);
+
+    Reader.setOffset(0);
+    FixedStreamArray<int> FixedIntsRef;
+    ASSERT_NO_ERROR(Reader.readArray(FixedIntsRef, Ints.size()));
+    ASSERT_EQ(0U, Reader.bytesRemaining());
+    ASSERT_EQ(Ints, std::vector<int>(FixedIntsRef.begin(), FixedIntsRef.end()));
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamReaderEnum) {
+  enum class MyEnum : int64_t { Foo = -10, Bar = 0, Baz = 10 };
+
+  std::vector<MyEnum> Enums = {MyEnum::Bar, MyEnum::Baz, MyEnum::Foo};
+
+  ArrayRef<uint8_t> Bytes(reinterpret_cast<const uint8_t *>(&Enums[0]),
+                          sizeof(MyEnum) * Enums.size());
+
+  initialize(Bytes, 0);
+  for (auto IS : InputStreams) {
+    BinaryStreamReader Reader(*IS);
+
+    MyEnum V1;
+    MyEnum V2;
+    MyEnum V3;
+    ArrayRef<MyEnum> Array;
+    FixedStreamArray<MyEnum> FSA;
+
+    ASSERT_NO_ERROR(Reader.readEnum(V1));
+    ASSERT_NO_ERROR(Reader.readEnum(V2));
+    ASSERT_NO_ERROR(Reader.readEnum(V3));
+    ASSERT_EQ(0U, Reader.bytesRemaining());
+
+    EXPECT_EQ(MyEnum::Bar, V1);
+    EXPECT_EQ(MyEnum::Baz, V2);
+    EXPECT_EQ(MyEnum::Foo, V3);
+
+    Reader.setOffset(0);
+    ASSERT_NO_ERROR(Reader.readArray(Array, 3));
+    EXPECT_EQ(makeArrayRef(Enums), Array);
+
+    Reader.setOffset(0);
+    ASSERT_NO_ERROR(Reader.readArray(FSA, 3));
+    EXPECT_EQ(Enums, std::vector<MyEnum>(FSA.begin(), FSA.end()));
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamReaderObject) {
+  struct Foo {
+    int X;
+    double Y;
+    char Z;
+  };
+
+  std::vector<Foo> Foos;
+  Foos.push_back({-42, 42.42, 42});
+  Foos.push_back({100, 3.1415, -89});
+
+  std::vector<uint8_t> Bytes;
+  Bytes.resize(2 * sizeof(Foo));
+  Foo *FPtr = reinterpret_cast<Foo *>(&Bytes[0]);
+  Foo *GPtr = FPtr + 1;
+
+  ::memcpy(FPtr, &Foos[0], sizeof(Foo));
+  ::memcpy(GPtr + sizeof(Foo), &Foos[1], sizeof(Foo));
+
+  initialize(Bytes, 0);
+
+  for (auto IS : InputStreams) {
+    // 1. Reading object pointers.
+    BinaryStreamReader Reader(*IS);
+    const Foo *FPtrOut = nullptr;
+    const Foo *GPtrOut = nullptr;
+    ASSERT_NO_ERROR(Reader.readObject(FPtrOut));
+    ASSERT_NO_ERROR(Reader.readObject(GPtrOut));
+    EXPECT_EQ(0U, Reader.bytesRemaining());
+    EXPECT_EQ(0, ::memcmp(FPtr, FPtrOut, sizeof(Foo)));
+    EXPECT_EQ(0, ::memcmp(GPtr, GPtrOut, sizeof(Foo)));
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamReaderStrings) {
+  std::vector<uint8_t> Bytes = {'O',  'n', 'e', '\0', 'T', 'w', 'o',
+                                '\0', 'T', 'h', 'r',  'e', 'e', '\0',
+                                'F',  'o', 'u', 'r',  '\0'};
+  initialize(Bytes, 0);
+
+  for (auto IS : InputStreams) {
+    BinaryStreamReader Reader(*IS);
+
+    StringRef S1;
+    StringRef S2;
+    StringRef S3;
+    StringRef S4;
+    ASSERT_NO_ERROR(Reader.readCString(S1));
+    ASSERT_NO_ERROR(Reader.readCString(S2));
+    ASSERT_NO_ERROR(Reader.readCString(S3));
+    ASSERT_NO_ERROR(Reader.readCString(S4));
+    ASSERT_EQ(0U, Reader.bytesRemaining());
+
+    EXPECT_EQ("One", S1);
+    EXPECT_EQ("Two", S2);
+    EXPECT_EQ("Three", S3);
+    EXPECT_EQ("Four", S4);
+
+    S1 = S2 = S3 = S4 = "";
+    Reader.setOffset(0);
+    ASSERT_NO_ERROR(Reader.readFixedString(S1, 3));
+    ASSERT_NO_ERROR(Reader.skip(1));
+    ASSERT_NO_ERROR(Reader.readFixedString(S2, 3));
+    ASSERT_NO_ERROR(Reader.skip(1));
+    ASSERT_NO_ERROR(Reader.readFixedString(S3, 5));
+    ASSERT_NO_ERROR(Reader.skip(1));
+    ASSERT_NO_ERROR(Reader.readFixedString(S4, 4));
+    ASSERT_NO_ERROR(Reader.skip(1));
+    ASSERT_EQ(0U, Reader.bytesRemaining());
+
+    EXPECT_EQ("One", S1);
+    EXPECT_EQ("Two", S2);
+    EXPECT_EQ("Three", S3);
+    EXPECT_EQ("Four", S4);
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamWriterBounds) {
+  initialize(5);
+
+  for (auto OS : OutputStreams) {
+    BinaryStreamWriter Writer(*OS);
+
+    // 1. Can write a string that exactly fills the buffer.
+    EXPECT_EQ(5U, Writer.bytesRemaining());
+    EXPECT_NO_ERROR(Writer.writeFixedString("abcde"));
+    EXPECT_EQ(0U, Writer.bytesRemaining());
+
+    // 2. Can write an empty string even when you're full
+    EXPECT_NO_ERROR(Writer.writeFixedString(""));
+    EXPECT_ERROR(Writer.writeFixedString("a"));
+
+    // 3. Can't write a string that is one character too long.
+    Writer.setOffset(0);
+    EXPECT_ERROR(Writer.writeFixedString("abcdef"));
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamWriterIntegers) {
+  support::ulittle64_t Little{908234};
+  support::ubig32_t Big{28907823};
+  short NS = 2897;
+  int NI = -89723;
+  unsigned long NUL = 902309023UL;
+  constexpr uint32_t Size =
+      sizeof(Little) + sizeof(Big) + sizeof(NS) + sizeof(NI) + sizeof(NUL);
+
+  initialize(Size);
+
+  for (auto OS : OutputStreams) {
+    BinaryStreamWriter Writer(*OS);
+
+    // 1. Writing fields individually.
+    ASSERT_NO_ERROR(Writer.writeObject(Little));
+    ASSERT_NO_ERROR(Writer.writeObject(Big));
+    ASSERT_NO_ERROR(Writer.writeInteger(NS));
+    ASSERT_NO_ERROR(Writer.writeInteger(NI));
+    ASSERT_NO_ERROR(Writer.writeInteger(NUL));
+    ASSERT_EQ(0U, Writer.bytesRemaining());
+
+    // Read them back in and confirm they're correct.
+    const ulittle64_t *Little2;
+    const ubig32_t *Big2;
+    short NS2;
+    int NI2;
+    unsigned long NUL2;
+    BinaryStreamReader Reader(*OS);
+    ASSERT_NO_ERROR(Reader.readObject(Little2));
+    ASSERT_NO_ERROR(Reader.readObject(Big2));
+    ASSERT_NO_ERROR(Reader.readInteger(NS2));
+    ASSERT_NO_ERROR(Reader.readInteger(NI2));
+    ASSERT_NO_ERROR(Reader.readInteger(NUL2));
+    EXPECT_EQ(Little, *Little2);
+    EXPECT_EQ(Big, *Big2);
+    EXPECT_EQ(NS, NS2);
+    EXPECT_EQ(NI, NI2);
+    EXPECT_EQ(NUL, NUL2);
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamWriterIntegerArrays) {
+  // 3. Arrays of integers
+  std::vector<int> SourceInts = {1, 2, 3, 4, 5};
+  ArrayRef<uint8_t> SourceBytes(reinterpret_cast<uint8_t *>(&SourceInts[0]),
+                                SourceInts.size() * sizeof(int));
+
+  initialize(SourceBytes, SourceBytes.size());
+
+  for (auto IS : InputStreams) {
+    for (auto OS : OutputStreams) {
+      BinaryStreamReader Reader(*IS);
+      BinaryStreamWriter Writer(*OS);
+      ArrayRef<int> Ints;
+      ArrayRef<int> Ints2;
+      // First read them, then write them, then read them back.
+      ASSERT_NO_ERROR(Reader.readArray(Ints, SourceInts.size()));
+      ASSERT_NO_ERROR(Writer.writeArray(Ints));
+
+      BinaryStreamReader ReaderBacker(*OS);
+      ASSERT_NO_ERROR(ReaderBacker.readArray(Ints2, SourceInts.size()));
+
+      EXPECT_EQ(makeArrayRef(SourceInts), Ints2);
+    }
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamWriterEnum) {
+  enum class MyEnum : int64_t { Foo = -10, Bar = 0, Baz = 10 };
+
+  std::vector<MyEnum> Expected = {MyEnum::Bar, MyEnum::Foo, MyEnum::Baz};
+
+  initialize(Expected.size() * sizeof(MyEnum));
+
+  for (auto OS : OutputStreams) {
+    BinaryStreamWriter Writer(*OS);
+    ArrayRef<MyEnum> Enums;
+    ArrayRef<MyEnum> Enums2;
+
+    // First read them, then write them, then read them back.
+    for (auto ME : Expected)
+      ASSERT_NO_ERROR(Writer.writeEnum(ME));
+
+    ArrayRef<MyEnum> Array;
+    BinaryStreamReader Reader(*OS);
+    ASSERT_NO_ERROR(Reader.readArray(Array, Expected.size()));
+
+    EXPECT_EQ(makeArrayRef(Expected), Array);
+  }
+}
+
+TEST_F(BinaryStreamTest, StringWriterStrings) {
+  StringRef Strings[] = {"First", "Second", "Third", "Fourth"};
+
+  size_t Length = 0;
+  for (auto S : Strings)
+    Length += S.size() + 1;
+  initialize(Length);
+
+  for (auto OS : OutputStreams) {
+    BinaryStreamWriter Writer(*OS);
+    for (auto S : Strings)
+      ASSERT_NO_ERROR(Writer.writeCString(S));
+
+    for (auto IS : InputStreams) {
+      std::vector<StringRef> InStrings;
+      BinaryStreamReader Reader(*IS);
+      while (!Reader.empty()) {
+        StringRef S;
+        ASSERT_NO_ERROR(Reader.readCString(S));
+        InStrings.push_back(S);
+      }
+      EXPECT_EQ(makeArrayRef(Strings), makeArrayRef(InStrings));
+    }
+  }
+}
+
+TEST_F(BinaryStreamTest, StreamReaderIntegersVariadic) {
+  uint8_t A = 201;
+  int8_t A2 = -92;
+  uint16_t B = 20823;
+  int16_t B2 = -20823;
+  uint32_t C = 8978251;
+  int32_t C2 = -8978251;
+  uint64_t D = 90278410232ULL;
+  int64_t D2 = -90278410232LL;
+
+  initialize(2 * (sizeof(A) + sizeof(B) + sizeof(C) + sizeof(D)));
+
+  for (auto OS : OutputStreams) {
+    BinaryStreamWriter Writer(*OS);
+    ASSERT_NO_ERROR(Writer.writeIntegers(A, A2, B, B2, C, C2, D, D2));
+
+    for (auto IS : InputStreams) {
+      BinaryStreamReader Reader(*IS);
+      uint8_t AX;
+      int8_t AX2;
+      uint16_t BX;
+      int16_t BX2;
+      uint32_t CX;
+      int32_t CX2;
+      uint64_t DX;
+      int64_t DX2;
+
+      ASSERT_NO_ERROR(Reader.readIntegers(AX, AX2, BX, BX2, CX, CX2, DX, DX2));
+      EXPECT_EQ(A, AX);
+      EXPECT_EQ(A2, AX2);
+      EXPECT_EQ(B, BX);
+      EXPECT_EQ(B2, BX2);
+      EXPECT_EQ(C, CX);
+      EXPECT_EQ(C2, CX2);
+      EXPECT_EQ(D, DX);
+      EXPECT_EQ(D2, DX2);
+    }
+  }
+}
+}
+
+namespace {
+struct BinaryItemStreamObject {
+  BinaryItemStreamObject(int X, float Y) : X(X), Y(Y) {}
+
+  int X;
+  float Y;
+};
+}
+
+namespace llvm {
+template <> struct BinaryItemTraits<std::unique_ptr<BinaryItemStreamObject>> {
+  size_t length(const std::unique_ptr<BinaryItemStreamObject> &Item) {
+    size_t S = sizeof(Item->X);
+    S += sizeof(Item->Y);
+    return S;
+  }
+
+  ArrayRef<uint8_t> bytes(const std::unique_ptr<BinaryItemStreamObject> &Item) {
+    // In practice we probably would use a more cheaply serializable type,
+    // or at the very least not allocate every single time.  This is just
+    // for illustration and testing though.
+    size_t Size = length(Item);
+    uint8_t *Buffer = Alloc.Allocate<uint8_t>(Size);
+    MutableBinaryByteStream Stream(MutableArrayRef<uint8_t>(Buffer, Size),
+                                   little);
+    BinaryStreamWriter Writer(Stream);
+    consumeError(Writer.writeInteger(Item->X));
+    consumeError(Writer.writeObject(Item->Y));
+    return makeArrayRef(Buffer, Size);
+  }
+
+private:
+  BumpPtrAllocator Alloc;
+};
+}
+
+namespace {
+
+TEST_F(BinaryStreamTest, BinaryItemStream) {
+  // Note that this is a vector of pointers, so individual records do not live
+  // contiguously in memory.
+  std::vector<std::unique_ptr<BinaryItemStreamObject>> Objects;
+  Objects.push_back(llvm::make_unique<BinaryItemStreamObject>(1, 1.0));
+  Objects.push_back(llvm::make_unique<BinaryItemStreamObject>(2, 2.0));
+  Objects.push_back(llvm::make_unique<BinaryItemStreamObject>(3, 3.0));
+
+  BinaryItemStream<std::unique_ptr<BinaryItemStreamObject>> ItemStream(little);
+  ItemStream.setItems(Objects);
+  BinaryStreamReader Reader(ItemStream);
+
+  for (int I = 0; I < 3; ++I) {
+    int X;
+    const float *Y;
+    ASSERT_NO_ERROR(Reader.readInteger(X));
+    ASSERT_NO_ERROR(Reader.readObject(Y));
+
+    EXPECT_EQ(Objects[I]->X, X);
+    EXPECT_DOUBLE_EQ(Objects[I]->Y, *Y);
+  }
+}
+
+} // end anonymous namespace