xref: /llvm-project/llvm/unittests/DebugInfo/MSF/MappedBlockStreamTest.cpp (revision 9fb9d71d3e6a0515cb0ad416bc4400d47801888a)
1 //===- llvm/unittest/DebugInfo/MSF/MappedBlockStreamTest.cpp --------------===//
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 "llvm/DebugInfo/MSF/MappedBlockStream.h"
11 #include "llvm/DebugInfo/MSF/IMSFFile.h"
12 #include "llvm/DebugInfo/MSF/MSFError.h"
13 #include "llvm/Support/BinaryByteStream.h"
14 #include "llvm/Support/BinaryStreamReader.h"
15 #include "llvm/Support/BinaryStreamRef.h"
16 #include "llvm/Support/BinaryStreamWriter.h"
17 #include "llvm/Testing/Support/Error.h"
18 
19 #include "gmock/gmock.h"
20 #include "gtest/gtest.h"
21 
22 #include <unordered_map>
23 
24 using namespace llvm;
25 using namespace llvm::msf;
26 using namespace llvm::support;
27 
28 namespace {
29 
30 static const uint32_t BlocksAry[] = {0, 1, 2, 5, 4, 3, 6, 7, 8, 9};
31 static uint8_t DataAry[] = {'A', 'B', 'C', 'F', 'E', 'D', 'G', 'H', 'I', 'J'};
32 
33 class DiscontiguousStream : public WritableBinaryStream {
34 public:
35   DiscontiguousStream(ArrayRef<uint32_t> Blocks, MutableArrayRef<uint8_t> Data)
36       : Blocks(Blocks.begin(), Blocks.end()), Data(Data.begin(), Data.end()) {}
37 
38   uint32_t block_size() const { return 1; }
39   uint32_t block_count() const { return Blocks.size(); }
40 
41   endianness getEndian() const override { return little; }
42 
43   Error readBytes(uint32_t Offset, uint32_t Size,
44                   ArrayRef<uint8_t> &Buffer) override {
45     if (auto EC = checkOffset(Offset, Size))
46       return EC;
47     Buffer = Data.slice(Offset, Size);
48     return Error::success();
49   }
50 
51   Error readLongestContiguousChunk(uint32_t Offset,
52                                    ArrayRef<uint8_t> &Buffer) override {
53     if (auto EC = checkOffset(Offset, 1))
54       return EC;
55     Buffer = Data.drop_front(Offset);
56     return Error::success();
57   }
58 
59   uint32_t getLength() override { return Data.size(); }
60 
61   Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> SrcData) override {
62     if (auto EC = checkOffset(Offset, SrcData.size()))
63       return EC;
64     ::memcpy(&Data[Offset], SrcData.data(), SrcData.size());
65     return Error::success();
66   }
67   Error commit() override { return Error::success(); }
68 
69   MSFStreamLayout layout() const {
70     return MSFStreamLayout{static_cast<uint32_t>(Data.size()), Blocks};
71   }
72 
73   BumpPtrAllocator Allocator;
74 
75 private:
76   std::vector<support::ulittle32_t> Blocks;
77   MutableArrayRef<uint8_t> Data;
78 };
79 
80 TEST(MappedBlockStreamTest, NumBlocks) {
81   DiscontiguousStream F(BlocksAry, DataAry);
82   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
83                                            F.Allocator);
84   EXPECT_EQ(F.block_size(), S->getBlockSize());
85   EXPECT_EQ(F.layout().Blocks.size(), S->getNumBlocks());
86 }
87 
88 // Tests that a read which is entirely contained within a single block works
89 // and does not allocate.
90 TEST(MappedBlockStreamTest, ReadBeyondEndOfStreamRef) {
91   DiscontiguousStream F(BlocksAry, DataAry);
92   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
93                                            F.Allocator);
94 
95   BinaryStreamReader R(*S);
96   BinaryStreamRef SR;
97   EXPECT_THAT_ERROR(R.readStreamRef(SR, 0U), Succeeded());
98   ArrayRef<uint8_t> Buffer;
99   EXPECT_THAT_ERROR(SR.readBytes(0U, 1U, Buffer), Failed());
100   EXPECT_THAT_ERROR(R.readStreamRef(SR, 1U), Succeeded());
101   EXPECT_THAT_ERROR(SR.readBytes(1U, 1U, Buffer), Failed());
102 }
103 
104 // Tests that a read which outputs into a full destination buffer works and
105 // does not fail due to the length of the output buffer.
106 TEST(MappedBlockStreamTest, ReadOntoNonEmptyBuffer) {
107   DiscontiguousStream F(BlocksAry, DataAry);
108   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
109                                            F.Allocator);
110 
111   BinaryStreamReader R(*S);
112   StringRef Str = "ZYXWVUTSRQPONMLKJIHGFEDCBA";
113   EXPECT_THAT_ERROR(R.readFixedString(Str, 1), Succeeded());
114   EXPECT_EQ(Str, StringRef("A"));
115   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
116 }
117 
118 // Tests that a read which crosses a block boundary, but where the subsequent
119 // blocks are still contiguous in memory to the previous block works and does
120 // not allocate memory.
121 TEST(MappedBlockStreamTest, ZeroCopyReadContiguousBreak) {
122   DiscontiguousStream F(BlocksAry, DataAry);
123   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
124                                            F.Allocator);
125   BinaryStreamReader R(*S);
126   StringRef Str;
127   EXPECT_THAT_ERROR(R.readFixedString(Str, 2), Succeeded());
128   EXPECT_EQ(Str, StringRef("AB"));
129   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
130 
131   R.setOffset(6);
132   EXPECT_THAT_ERROR(R.readFixedString(Str, 4), Succeeded());
133   EXPECT_EQ(Str, StringRef("GHIJ"));
134   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
135 }
136 
137 // Tests that a read which crosses a block boundary and cannot be referenced
138 // contiguously works and allocates only the precise amount of bytes
139 // requested.
140 TEST(MappedBlockStreamTest, CopyReadNonContiguousBreak) {
141   DiscontiguousStream F(BlocksAry, DataAry);
142   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
143                                            F.Allocator);
144   BinaryStreamReader R(*S);
145   StringRef Str;
146   EXPECT_THAT_ERROR(R.readFixedString(Str, 10), Succeeded());
147   EXPECT_EQ(Str, StringRef("ABCDEFGHIJ"));
148   EXPECT_EQ(10U, F.Allocator.getBytesAllocated());
149 }
150 
151 // Test that an out of bounds read which doesn't cross a block boundary
152 // fails and allocates no memory.
153 TEST(MappedBlockStreamTest, InvalidReadSizeNoBreak) {
154   DiscontiguousStream F(BlocksAry, DataAry);
155   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
156                                            F.Allocator);
157   BinaryStreamReader R(*S);
158   StringRef Str;
159 
160   R.setOffset(10);
161   EXPECT_THAT_ERROR(R.readFixedString(Str, 1), Failed());
162   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
163 }
164 
165 // Test that an out of bounds read which crosses a contiguous block boundary
166 // fails and allocates no memory.
167 TEST(MappedBlockStreamTest, InvalidReadSizeContiguousBreak) {
168   DiscontiguousStream F(BlocksAry, DataAry);
169   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
170                                            F.Allocator);
171   BinaryStreamReader R(*S);
172   StringRef Str;
173 
174   R.setOffset(6);
175   EXPECT_THAT_ERROR(R.readFixedString(Str, 5), Failed());
176   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
177 }
178 
179 // Test that an out of bounds read which crosses a discontiguous block
180 // boundary fails and allocates no memory.
181 TEST(MappedBlockStreamTest, InvalidReadSizeNonContiguousBreak) {
182   DiscontiguousStream F(BlocksAry, DataAry);
183   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
184                                            F.Allocator);
185   BinaryStreamReader R(*S);
186   StringRef Str;
187 
188   EXPECT_THAT_ERROR(R.readFixedString(Str, 11), Failed());
189   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
190 }
191 
192 // Tests that a read which is entirely contained within a single block but
193 // beyond the end of a StreamRef fails.
194 TEST(MappedBlockStreamTest, ZeroCopyReadNoBreak) {
195   DiscontiguousStream F(BlocksAry, DataAry);
196   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
197                                            F.Allocator);
198   BinaryStreamReader R(*S);
199   StringRef Str;
200   EXPECT_THAT_ERROR(R.readFixedString(Str, 1), Succeeded());
201   EXPECT_EQ(Str, StringRef("A"));
202   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
203 }
204 
205 // Tests that a read which is not aligned on the same boundary as a previous
206 // cached request, but which is known to overlap that request, shares the
207 // previous allocation.
208 TEST(MappedBlockStreamTest, UnalignedOverlappingRead) {
209   DiscontiguousStream F(BlocksAry, DataAry);
210   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
211                                            F.Allocator);
212   BinaryStreamReader R(*S);
213   StringRef Str1;
214   StringRef Str2;
215   EXPECT_THAT_ERROR(R.readFixedString(Str1, 7), Succeeded());
216   EXPECT_EQ(Str1, StringRef("ABCDEFG"));
217   EXPECT_EQ(7U, F.Allocator.getBytesAllocated());
218 
219   R.setOffset(2);
220   EXPECT_THAT_ERROR(R.readFixedString(Str2, 3), Succeeded());
221   EXPECT_EQ(Str2, StringRef("CDE"));
222   EXPECT_EQ(Str1.data() + 2, Str2.data());
223   EXPECT_EQ(7U, F.Allocator.getBytesAllocated());
224 }
225 
226 // Tests that a read which is not aligned on the same boundary as a previous
227 // cached request, but which only partially overlaps a previous cached request,
228 // still works correctly and allocates again from the shared pool.
229 TEST(MappedBlockStreamTest, UnalignedOverlappingReadFail) {
230   DiscontiguousStream F(BlocksAry, DataAry);
231   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
232                                            F.Allocator);
233   BinaryStreamReader R(*S);
234   StringRef Str1;
235   StringRef Str2;
236   EXPECT_THAT_ERROR(R.readFixedString(Str1, 6), Succeeded());
237   EXPECT_EQ(Str1, StringRef("ABCDEF"));
238   EXPECT_EQ(6U, F.Allocator.getBytesAllocated());
239 
240   R.setOffset(4);
241   EXPECT_THAT_ERROR(R.readFixedString(Str2, 4), Succeeded());
242   EXPECT_EQ(Str2, StringRef("EFGH"));
243   EXPECT_EQ(10U, F.Allocator.getBytesAllocated());
244 }
245 
246 TEST(MappedBlockStreamTest, WriteBeyondEndOfStream) {
247   static uint8_t Data[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J'};
248   static uint8_t LargeBuffer[] = {'0', '1', '2', '3', '4', '5',
249                                   '6', '7', '8', '9', 'A'};
250   static uint8_t SmallBuffer[] = {'0', '1', '2'};
251   static_assert(sizeof(LargeBuffer) > sizeof(Data),
252                 "LargeBuffer is not big enough");
253 
254   DiscontiguousStream F(BlocksAry, Data);
255   auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
256                                                    F, F.Allocator);
257   ArrayRef<uint8_t> Buffer;
258 
259   EXPECT_THAT_ERROR(S->writeBytes(0, ArrayRef<uint8_t>(LargeBuffer)), Failed());
260   EXPECT_THAT_ERROR(S->writeBytes(0, ArrayRef<uint8_t>(SmallBuffer)),
261                     Succeeded());
262   EXPECT_THAT_ERROR(S->writeBytes(7, ArrayRef<uint8_t>(SmallBuffer)),
263                     Succeeded());
264   EXPECT_THAT_ERROR(S->writeBytes(8, ArrayRef<uint8_t>(SmallBuffer)), Failed());
265 }
266 
267 TEST(MappedBlockStreamTest, TestWriteBytesNoBreakBoundary) {
268   static uint8_t Data[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J'};
269   DiscontiguousStream F(BlocksAry, Data);
270   auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
271                                                    F, F.Allocator);
272   ArrayRef<uint8_t> Buffer;
273 
274   EXPECT_THAT_ERROR(S->readBytes(0, 1, Buffer), Succeeded());
275   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('A'));
276   EXPECT_THAT_ERROR(S->readBytes(9, 1, Buffer), Succeeded());
277   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('J'));
278 
279   EXPECT_THAT_ERROR(S->writeBytes(0, ArrayRef<uint8_t>('J')), Succeeded());
280   EXPECT_THAT_ERROR(S->writeBytes(9, ArrayRef<uint8_t>('A')), Succeeded());
281 
282   EXPECT_THAT_ERROR(S->readBytes(0, 1, Buffer), Succeeded());
283   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('J'));
284   EXPECT_THAT_ERROR(S->readBytes(9, 1, Buffer), Succeeded());
285   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('A'));
286 
287   EXPECT_THAT_ERROR(S->writeBytes(0, ArrayRef<uint8_t>('A')), Succeeded());
288   EXPECT_THAT_ERROR(S->writeBytes(9, ArrayRef<uint8_t>('J')), Succeeded());
289 
290   EXPECT_THAT_ERROR(S->readBytes(0, 1, Buffer), Succeeded());
291   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('A'));
292   EXPECT_THAT_ERROR(S->readBytes(9, 1, Buffer), Succeeded());
293   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('J'));
294 }
295 
296 TEST(MappedBlockStreamTest, TestWriteBytesBreakBoundary) {
297   static uint8_t Data[] = {'0', '0', '0', '0', '0', '0', '0', '0', '0', '0'};
298   static uint8_t TestData[] = {'T', 'E', 'S', 'T', 'I', 'N', 'G', '.'};
299   static uint8_t Expected[] = {'T', 'E', 'S', 'N', 'I',
300                                'T', 'G', '.', '0', '0'};
301 
302   DiscontiguousStream F(BlocksAry, Data);
303   auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
304                                                    F, F.Allocator);
305   ArrayRef<uint8_t> Buffer;
306 
307   EXPECT_THAT_ERROR(S->writeBytes(0, TestData), Succeeded());
308   // First just compare the memory, then compare the result of reading the
309   // string out.
310   EXPECT_EQ(ArrayRef<uint8_t>(Data), ArrayRef<uint8_t>(Expected));
311 
312   EXPECT_THAT_ERROR(S->readBytes(0, 8, Buffer), Succeeded());
313   EXPECT_EQ(Buffer, ArrayRef<uint8_t>(TestData));
314 }
315 
316 TEST(MappedBlockStreamTest, TestWriteThenRead) {
317   std::vector<uint8_t> DataBytes(10);
318   MutableArrayRef<uint8_t> Data(DataBytes);
319   const uint32_t Blocks[] = {2, 1, 0, 6, 3, 4, 5, 7, 9, 8};
320 
321   DiscontiguousStream F(Blocks, Data);
322   auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
323                                                    F, F.Allocator);
324 
325   enum class MyEnum : uint32_t { Val1 = 2908234, Val2 = 120891234 };
326   using support::ulittle32_t;
327 
328   uint16_t u16[] = {31468, 0};
329   uint32_t u32[] = {890723408, 0};
330   MyEnum Enum[] = {MyEnum::Val1, MyEnum::Val2};
331   StringRef ZStr[] = {"Zero Str", ""};
332   StringRef FStr[] = {"Fixed Str", ""};
333   uint8_t byteArray0[] = {'1', '2'};
334   uint8_t byteArray1[] = {'0', '0'};
335   ArrayRef<uint8_t> byteArrayRef0(byteArray0);
336   ArrayRef<uint8_t> byteArrayRef1(byteArray1);
337   ArrayRef<uint8_t> byteArray[] = {byteArrayRef0, byteArrayRef1};
338   uint32_t intArr0[] = {890723408, 29082234};
339   uint32_t intArr1[] = {890723408, 29082234};
340   ArrayRef<uint32_t> intArray[] = {intArr0, intArr1};
341 
342   BinaryStreamReader Reader(*S);
343   BinaryStreamWriter Writer(*S);
344   EXPECT_THAT_ERROR(Writer.writeInteger(u16[0]), Succeeded());
345   EXPECT_THAT_ERROR(Reader.readInteger(u16[1]), Succeeded());
346   EXPECT_EQ(u16[0], u16[1]);
347   EXPECT_EQ(std::vector<uint8_t>({0, 0x7A, 0xEC, 0, 0, 0, 0, 0, 0, 0}),
348             DataBytes);
349 
350   Reader.setOffset(0);
351   Writer.setOffset(0);
352   ::memset(DataBytes.data(), 0, 10);
353   EXPECT_THAT_ERROR(Writer.writeInteger(u32[0]), Succeeded());
354   EXPECT_THAT_ERROR(Reader.readInteger(u32[1]), Succeeded());
355   EXPECT_EQ(u32[0], u32[1]);
356   EXPECT_EQ(std::vector<uint8_t>({0x17, 0x5C, 0x50, 0, 0, 0, 0x35, 0, 0, 0}),
357             DataBytes);
358 
359   Reader.setOffset(0);
360   Writer.setOffset(0);
361   ::memset(DataBytes.data(), 0, 10);
362   EXPECT_THAT_ERROR(Writer.writeEnum(Enum[0]), Succeeded());
363   EXPECT_THAT_ERROR(Reader.readEnum(Enum[1]), Succeeded());
364   EXPECT_EQ(Enum[0], Enum[1]);
365   EXPECT_EQ(std::vector<uint8_t>({0x2C, 0x60, 0x4A, 0, 0, 0, 0, 0, 0, 0}),
366             DataBytes);
367 
368   Reader.setOffset(0);
369   Writer.setOffset(0);
370   ::memset(DataBytes.data(), 0, 10);
371   EXPECT_THAT_ERROR(Writer.writeCString(ZStr[0]), Succeeded());
372   EXPECT_THAT_ERROR(Reader.readCString(ZStr[1]), Succeeded());
373   EXPECT_EQ(ZStr[0], ZStr[1]);
374   EXPECT_EQ(
375       std::vector<uint8_t>({'r', 'e', 'Z', ' ', 'S', 't', 'o', 'r', 0, 0}),
376       DataBytes);
377 
378   Reader.setOffset(0);
379   Writer.setOffset(0);
380   ::memset(DataBytes.data(), 0, 10);
381   EXPECT_THAT_ERROR(Writer.writeFixedString(FStr[0]), Succeeded());
382   EXPECT_THAT_ERROR(Reader.readFixedString(FStr[1], FStr[0].size()),
383                     Succeeded());
384   EXPECT_EQ(FStr[0], FStr[1]);
385   EXPECT_EQ(
386       std::vector<uint8_t>({'x', 'i', 'F', 'd', ' ', 'S', 'e', 't', 0, 'r'}),
387       DataBytes);
388 
389   Reader.setOffset(0);
390   Writer.setOffset(0);
391   ::memset(DataBytes.data(), 0, 10);
392   EXPECT_THAT_ERROR(Writer.writeArray(byteArray[0]), Succeeded());
393   EXPECT_THAT_ERROR(Reader.readArray(byteArray[1], byteArray[0].size()),
394                     Succeeded());
395   EXPECT_EQ(byteArray[0], byteArray[1]);
396   EXPECT_EQ(std::vector<uint8_t>({0, 0x32, 0x31, 0, 0, 0, 0, 0, 0, 0}),
397             DataBytes);
398 
399   Reader.setOffset(0);
400   Writer.setOffset(0);
401   ::memset(DataBytes.data(), 0, 10);
402   EXPECT_THAT_ERROR(Writer.writeArray(intArray[0]), Succeeded());
403   EXPECT_THAT_ERROR(Reader.readArray(intArray[1], intArray[0].size()),
404                     Succeeded());
405   EXPECT_EQ(intArray[0], intArray[1]);
406 }
407 
408 TEST(MappedBlockStreamTest, TestWriteContiguousStreamRef) {
409   std::vector<uint8_t> DestDataBytes(10);
410   MutableArrayRef<uint8_t> DestData(DestDataBytes);
411   const uint32_t DestBlocks[] = {2, 1, 0, 6, 3, 4, 5, 7, 9, 8};
412 
413   std::vector<uint8_t> SrcDataBytes(10);
414   MutableArrayRef<uint8_t> SrcData(SrcDataBytes);
415 
416   DiscontiguousStream F(DestBlocks, DestData);
417   auto DestStream = WritableMappedBlockStream::createStream(
418       F.block_size(), F.layout(), F, F.Allocator);
419 
420   // First write "Test Str" into the source stream.
421   MutableBinaryByteStream SourceStream(SrcData, little);
422   BinaryStreamWriter SourceWriter(SourceStream);
423   EXPECT_THAT_ERROR(SourceWriter.writeCString("Test Str"), Succeeded());
424   EXPECT_EQ(SrcDataBytes, std::vector<uint8_t>(
425                               {'T', 'e', 's', 't', ' ', 'S', 't', 'r', 0, 0}));
426 
427   // Then write the source stream into the dest stream.
428   BinaryStreamWriter DestWriter(*DestStream);
429   EXPECT_THAT_ERROR(DestWriter.writeStreamRef(SourceStream), Succeeded());
430   EXPECT_EQ(DestDataBytes, std::vector<uint8_t>(
431                                {'s', 'e', 'T', ' ', 'S', 't', 't', 'r', 0, 0}));
432 
433   // Then read the string back out of the dest stream.
434   StringRef Result;
435   BinaryStreamReader DestReader(*DestStream);
436   EXPECT_THAT_ERROR(DestReader.readCString(Result), Succeeded());
437   EXPECT_EQ(Result, "Test Str");
438 }
439 
440 TEST(MappedBlockStreamTest, TestWriteDiscontiguousStreamRef) {
441   std::vector<uint8_t> DestDataBytes(10);
442   MutableArrayRef<uint8_t> DestData(DestDataBytes);
443   const uint32_t DestBlocks[] = {2, 1, 0, 6, 3, 4, 5, 7, 9, 8};
444 
445   std::vector<uint8_t> SrcDataBytes(10);
446   MutableArrayRef<uint8_t> SrcData(SrcDataBytes);
447   const uint32_t SrcBlocks[] = {1, 0, 6, 3, 4, 5, 2, 7, 8, 9};
448 
449   DiscontiguousStream DestF(DestBlocks, DestData);
450   DiscontiguousStream SrcF(SrcBlocks, SrcData);
451 
452   auto Dest = WritableMappedBlockStream::createStream(
453       DestF.block_size(), DestF.layout(), DestF, DestF.Allocator);
454   auto Src = WritableMappedBlockStream::createStream(
455       SrcF.block_size(), SrcF.layout(), SrcF, SrcF.Allocator);
456 
457   // First write "Test Str" into the source stream.
458   BinaryStreamWriter SourceWriter(*Src);
459   EXPECT_THAT_ERROR(SourceWriter.writeCString("Test Str"), Succeeded());
460   EXPECT_EQ(SrcDataBytes, std::vector<uint8_t>(
461                               {'e', 'T', 't', 't', ' ', 'S', 's', 'r', 0, 0}));
462 
463   // Then write the source stream into the dest stream.
464   BinaryStreamWriter DestWriter(*Dest);
465   EXPECT_THAT_ERROR(DestWriter.writeStreamRef(*Src), Succeeded());
466   EXPECT_EQ(DestDataBytes, std::vector<uint8_t>(
467                                {'s', 'e', 'T', ' ', 'S', 't', 't', 'r', 0, 0}));
468 
469   // Then read the string back out of the dest stream.
470   StringRef Result;
471   BinaryStreamReader DestReader(*Dest);
472   EXPECT_THAT_ERROR(DestReader.readCString(Result), Succeeded());
473   EXPECT_EQ(Result, "Test Str");
474 }
475 
476 TEST(MappedBlockStreamTest, DataLivesAfterStreamDestruction) {
477   std::vector<uint8_t> DataBytes(10);
478   MutableArrayRef<uint8_t> Data(DataBytes);
479   const uint32_t Blocks[] = {2, 1, 0, 6, 3, 4, 5, 7, 9, 8};
480 
481   StringRef Str[] = {"Zero Str", ""};
482 
483   DiscontiguousStream F(Blocks, Data);
484   {
485     auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
486                                                      F, F.Allocator);
487 
488     BinaryStreamReader Reader(*S);
489     BinaryStreamWriter Writer(*S);
490     ::memset(DataBytes.data(), 0, 10);
491     EXPECT_THAT_ERROR(Writer.writeCString(Str[0]), Succeeded());
492     EXPECT_THAT_ERROR(Reader.readCString(Str[1]), Succeeded());
493     EXPECT_EQ(Str[0], Str[1]);
494   }
495 
496   EXPECT_EQ(Str[0], Str[1]);
497 }
498 } // namespace
499 
500 MATCHER_P3(BlockIsFilledWith, Layout, BlockIndex, Byte, "succeeded") {
501   uint64_t Offset = msf::blockToOffset(BlockIndex, Layout.SB->BlockSize);
502   ArrayRef<uint8_t> BufferRef = makeArrayRef(arg);
503   BufferRef = BufferRef.slice(Offset, Layout.SB->BlockSize);
504   return llvm::all_of(BufferRef, [this](uint8_t B) { return B == Byte; });
505 }
506 
507 namespace {
508 TEST(MappedBlockStreamTest, CreateFpmStream) {
509   BumpPtrAllocator Allocator;
510   SuperBlock SB;
511   MSFLayout L;
512   L.SB = &SB;
513 
514   SB.FreeBlockMapBlock = 1;
515   SB.BlockSize = 4096;
516 
517   constexpr uint32_t NumFileBlocks = 4096 * 4;
518 
519   std::vector<uint8_t> MsfBuffer(NumFileBlocks * SB.BlockSize);
520   MutableBinaryByteStream MsfStream(MsfBuffer, llvm::support::little);
521 
522   SB.NumBlocks = NumFileBlocks;
523   auto FpmStream =
524       WritableMappedBlockStream::createFpmStream(L, MsfStream, Allocator);
525   // 4096 * 4 / 8 = 2048 bytes of FPM data is needed to describe 4096 * 4
526   // blocks.  This translates to 1 FPM block.
527   EXPECT_EQ(2048u, FpmStream->getLength());
528   EXPECT_EQ(1u, FpmStream->getStreamLayout().Blocks.size());
529   EXPECT_EQ(1u, FpmStream->getStreamLayout().Blocks[0]);
530   // All blocks from FPM1 should be 1 initialized, and all blocks from FPM2
531   // should be 0 initialized (since we requested the main FPM, not the alt FPM)
532   for (int I = 0; I < 4; ++I) {
533     EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 1 + I * SB.BlockSize, 0xFF));
534     EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 2 + I * SB.BlockSize, 0));
535   }
536 
537   ::memset(MsfBuffer.data(), 0, MsfBuffer.size());
538   FpmStream =
539       WritableMappedBlockStream::createFpmStream(L, MsfStream, Allocator, true);
540   // 4096 * 4 / 8 = 2048 bytes of FPM data is needed to describe 4096 * 4
541   // blocks.  This translates to 1 FPM block.
542   EXPECT_EQ(2048u, FpmStream->getLength());
543   EXPECT_EQ(1u, FpmStream->getStreamLayout().Blocks.size());
544   EXPECT_EQ(2u, FpmStream->getStreamLayout().Blocks[0]);
545   // All blocks from FPM2 should be 1 initialized, and all blocks from FPM1
546   // should be 0 initialized (since we requested the alt FPM, not the main FPM)
547   for (int I = 0; I < 4; ++I) {
548     EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 1 + I * SB.BlockSize, 0));
549     EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 2 + I * SB.BlockSize, 0xFF));
550   }
551 }
552 
553 } // end anonymous namespace
554