xref: /llvm-project/llvm/unittests/DebugInfo/MSF/MappedBlockStreamTest.cpp (revision 2946cd701067404b99c39fb29dc9c74bd7193eb3)
1 //===- llvm/unittest/DebugInfo/MSF/MappedBlockStreamTest.cpp --------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/DebugInfo/MSF/MappedBlockStream.h"
10 #include "llvm/Support/BinaryByteStream.h"
11 #include "llvm/Support/BinaryStreamReader.h"
12 #include "llvm/Support/BinaryStreamRef.h"
13 #include "llvm/Support/BinaryStreamWriter.h"
14 #include "llvm/Testing/Support/Error.h"
15 
16 #include "gmock/gmock.h"
17 #include "gtest/gtest.h"
18 
19 
20 using namespace llvm;
21 using namespace llvm::msf;
22 using namespace llvm::support;
23 
24 namespace {
25 
26 static const uint32_t BlocksAry[] = {0, 1, 2, 5, 4, 3, 6, 7, 8, 9};
27 static uint8_t DataAry[] = {'A', 'B', 'C', 'F', 'E', 'D', 'G', 'H', 'I', 'J'};
28 
29 class DiscontiguousStream : public WritableBinaryStream {
30 public:
31   DiscontiguousStream(ArrayRef<uint32_t> Blocks, MutableArrayRef<uint8_t> Data)
32       : Blocks(Blocks.begin(), Blocks.end()), Data(Data.begin(), Data.end()) {}
33 
34   uint32_t block_size() const { return 1; }
35   uint32_t block_count() const { return Blocks.size(); }
36 
37   endianness getEndian() const override { return little; }
38 
39   Error readBytes(uint32_t Offset, uint32_t Size,
40                   ArrayRef<uint8_t> &Buffer) override {
41     if (auto EC = checkOffsetForRead(Offset, Size))
42       return EC;
43     Buffer = Data.slice(Offset, Size);
44     return Error::success();
45   }
46 
47   Error readLongestContiguousChunk(uint32_t Offset,
48                                    ArrayRef<uint8_t> &Buffer) override {
49     if (auto EC = checkOffsetForRead(Offset, 1))
50       return EC;
51     Buffer = Data.drop_front(Offset);
52     return Error::success();
53   }
54 
55   uint32_t getLength() override { return Data.size(); }
56 
57   Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> SrcData) override {
58     if (auto EC = checkOffsetForWrite(Offset, SrcData.size()))
59       return EC;
60     ::memcpy(&Data[Offset], SrcData.data(), SrcData.size());
61     return Error::success();
62   }
63   Error commit() override { return Error::success(); }
64 
65   MSFStreamLayout layout() const {
66     return MSFStreamLayout{static_cast<uint32_t>(Data.size()), Blocks};
67   }
68 
69   BumpPtrAllocator Allocator;
70 
71 private:
72   std::vector<support::ulittle32_t> Blocks;
73   MutableArrayRef<uint8_t> Data;
74 };
75 
76 TEST(MappedBlockStreamTest, NumBlocks) {
77   DiscontiguousStream F(BlocksAry, DataAry);
78   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
79                                            F.Allocator);
80   EXPECT_EQ(F.block_size(), S->getBlockSize());
81   EXPECT_EQ(F.layout().Blocks.size(), S->getNumBlocks());
82 }
83 
84 // Tests that a read which is entirely contained within a single block works
85 // and does not allocate.
86 TEST(MappedBlockStreamTest, ReadBeyondEndOfStreamRef) {
87   DiscontiguousStream F(BlocksAry, DataAry);
88   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
89                                            F.Allocator);
90 
91   BinaryStreamReader R(*S);
92   BinaryStreamRef SR;
93   EXPECT_THAT_ERROR(R.readStreamRef(SR, 0U), Succeeded());
94   ArrayRef<uint8_t> Buffer;
95   EXPECT_THAT_ERROR(SR.readBytes(0U, 1U, Buffer), Failed());
96   EXPECT_THAT_ERROR(R.readStreamRef(SR, 1U), Succeeded());
97   EXPECT_THAT_ERROR(SR.readBytes(1U, 1U, Buffer), Failed());
98 }
99 
100 // Tests that a read which outputs into a full destination buffer works and
101 // does not fail due to the length of the output buffer.
102 TEST(MappedBlockStreamTest, ReadOntoNonEmptyBuffer) {
103   DiscontiguousStream F(BlocksAry, DataAry);
104   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
105                                            F.Allocator);
106 
107   BinaryStreamReader R(*S);
108   StringRef Str = "ZYXWVUTSRQPONMLKJIHGFEDCBA";
109   EXPECT_THAT_ERROR(R.readFixedString(Str, 1), Succeeded());
110   EXPECT_EQ(Str, StringRef("A"));
111   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
112 }
113 
114 // Tests that a read which crosses a block boundary, but where the subsequent
115 // blocks are still contiguous in memory to the previous block works and does
116 // not allocate memory.
117 TEST(MappedBlockStreamTest, ZeroCopyReadContiguousBreak) {
118   DiscontiguousStream F(BlocksAry, DataAry);
119   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
120                                            F.Allocator);
121   BinaryStreamReader R(*S);
122   StringRef Str;
123   EXPECT_THAT_ERROR(R.readFixedString(Str, 2), Succeeded());
124   EXPECT_EQ(Str, StringRef("AB"));
125   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
126 
127   R.setOffset(6);
128   EXPECT_THAT_ERROR(R.readFixedString(Str, 4), Succeeded());
129   EXPECT_EQ(Str, StringRef("GHIJ"));
130   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
131 }
132 
133 // Tests that a read which crosses a block boundary and cannot be referenced
134 // contiguously works and allocates only the precise amount of bytes
135 // requested.
136 TEST(MappedBlockStreamTest, CopyReadNonContiguousBreak) {
137   DiscontiguousStream F(BlocksAry, DataAry);
138   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
139                                            F.Allocator);
140   BinaryStreamReader R(*S);
141   StringRef Str;
142   EXPECT_THAT_ERROR(R.readFixedString(Str, 10), Succeeded());
143   EXPECT_EQ(Str, StringRef("ABCDEFGHIJ"));
144   EXPECT_EQ(10U, F.Allocator.getBytesAllocated());
145 }
146 
147 // Test that an out of bounds read which doesn't cross a block boundary
148 // fails and allocates no memory.
149 TEST(MappedBlockStreamTest, InvalidReadSizeNoBreak) {
150   DiscontiguousStream F(BlocksAry, DataAry);
151   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
152                                            F.Allocator);
153   BinaryStreamReader R(*S);
154   StringRef Str;
155 
156   R.setOffset(10);
157   EXPECT_THAT_ERROR(R.readFixedString(Str, 1), Failed());
158   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
159 }
160 
161 // Test that an out of bounds read which crosses a contiguous block boundary
162 // fails and allocates no memory.
163 TEST(MappedBlockStreamTest, InvalidReadSizeContiguousBreak) {
164   DiscontiguousStream F(BlocksAry, DataAry);
165   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
166                                            F.Allocator);
167   BinaryStreamReader R(*S);
168   StringRef Str;
169 
170   R.setOffset(6);
171   EXPECT_THAT_ERROR(R.readFixedString(Str, 5), Failed());
172   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
173 }
174 
175 // Test that an out of bounds read which crosses a discontiguous block
176 // boundary fails and allocates no memory.
177 TEST(MappedBlockStreamTest, InvalidReadSizeNonContiguousBreak) {
178   DiscontiguousStream F(BlocksAry, DataAry);
179   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
180                                            F.Allocator);
181   BinaryStreamReader R(*S);
182   StringRef Str;
183 
184   EXPECT_THAT_ERROR(R.readFixedString(Str, 11), Failed());
185   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
186 }
187 
188 // Tests that a read which is entirely contained within a single block but
189 // beyond the end of a StreamRef fails.
190 TEST(MappedBlockStreamTest, ZeroCopyReadNoBreak) {
191   DiscontiguousStream F(BlocksAry, DataAry);
192   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
193                                            F.Allocator);
194   BinaryStreamReader R(*S);
195   StringRef Str;
196   EXPECT_THAT_ERROR(R.readFixedString(Str, 1), Succeeded());
197   EXPECT_EQ(Str, StringRef("A"));
198   EXPECT_EQ(0U, F.Allocator.getBytesAllocated());
199 }
200 
201 // Tests that a read which is not aligned on the same boundary as a previous
202 // cached request, but which is known to overlap that request, shares the
203 // previous allocation.
204 TEST(MappedBlockStreamTest, UnalignedOverlappingRead) {
205   DiscontiguousStream F(BlocksAry, DataAry);
206   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
207                                            F.Allocator);
208   BinaryStreamReader R(*S);
209   StringRef Str1;
210   StringRef Str2;
211   EXPECT_THAT_ERROR(R.readFixedString(Str1, 7), Succeeded());
212   EXPECT_EQ(Str1, StringRef("ABCDEFG"));
213   EXPECT_EQ(7U, F.Allocator.getBytesAllocated());
214 
215   R.setOffset(2);
216   EXPECT_THAT_ERROR(R.readFixedString(Str2, 3), Succeeded());
217   EXPECT_EQ(Str2, StringRef("CDE"));
218   EXPECT_EQ(Str1.data() + 2, Str2.data());
219   EXPECT_EQ(7U, F.Allocator.getBytesAllocated());
220 }
221 
222 // Tests that a read which is not aligned on the same boundary as a previous
223 // cached request, but which only partially overlaps a previous cached request,
224 // still works correctly and allocates again from the shared pool.
225 TEST(MappedBlockStreamTest, UnalignedOverlappingReadFail) {
226   DiscontiguousStream F(BlocksAry, DataAry);
227   auto S = MappedBlockStream::createStream(F.block_size(), F.layout(), F,
228                                            F.Allocator);
229   BinaryStreamReader R(*S);
230   StringRef Str1;
231   StringRef Str2;
232   EXPECT_THAT_ERROR(R.readFixedString(Str1, 6), Succeeded());
233   EXPECT_EQ(Str1, StringRef("ABCDEF"));
234   EXPECT_EQ(6U, F.Allocator.getBytesAllocated());
235 
236   R.setOffset(4);
237   EXPECT_THAT_ERROR(R.readFixedString(Str2, 4), Succeeded());
238   EXPECT_EQ(Str2, StringRef("EFGH"));
239   EXPECT_EQ(10U, F.Allocator.getBytesAllocated());
240 }
241 
242 TEST(MappedBlockStreamTest, WriteBeyondEndOfStream) {
243   static uint8_t Data[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J'};
244   static uint8_t LargeBuffer[] = {'0', '1', '2', '3', '4', '5',
245                                   '6', '7', '8', '9', 'A'};
246   static uint8_t SmallBuffer[] = {'0', '1', '2'};
247   static_assert(sizeof(LargeBuffer) > sizeof(Data),
248                 "LargeBuffer is not big enough");
249 
250   DiscontiguousStream F(BlocksAry, Data);
251   auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
252                                                    F, F.Allocator);
253   EXPECT_THAT_ERROR(S->writeBytes(0, ArrayRef<uint8_t>(LargeBuffer)), Failed());
254   EXPECT_THAT_ERROR(S->writeBytes(0, ArrayRef<uint8_t>(SmallBuffer)),
255                     Succeeded());
256   EXPECT_THAT_ERROR(S->writeBytes(7, ArrayRef<uint8_t>(SmallBuffer)),
257                     Succeeded());
258   EXPECT_THAT_ERROR(S->writeBytes(8, ArrayRef<uint8_t>(SmallBuffer)), Failed());
259 }
260 
261 TEST(MappedBlockStreamTest, TestWriteBytesNoBreakBoundary) {
262   static uint8_t Data[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J'};
263   DiscontiguousStream F(BlocksAry, Data);
264   auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
265                                                    F, F.Allocator);
266   ArrayRef<uint8_t> Buffer;
267 
268   EXPECT_THAT_ERROR(S->readBytes(0, 1, Buffer), Succeeded());
269   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('A'));
270   EXPECT_THAT_ERROR(S->readBytes(9, 1, Buffer), Succeeded());
271   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('J'));
272 
273   EXPECT_THAT_ERROR(S->writeBytes(0, ArrayRef<uint8_t>('J')), Succeeded());
274   EXPECT_THAT_ERROR(S->writeBytes(9, ArrayRef<uint8_t>('A')), Succeeded());
275 
276   EXPECT_THAT_ERROR(S->readBytes(0, 1, Buffer), Succeeded());
277   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('J'));
278   EXPECT_THAT_ERROR(S->readBytes(9, 1, Buffer), Succeeded());
279   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('A'));
280 
281   EXPECT_THAT_ERROR(S->writeBytes(0, ArrayRef<uint8_t>('A')), Succeeded());
282   EXPECT_THAT_ERROR(S->writeBytes(9, ArrayRef<uint8_t>('J')), Succeeded());
283 
284   EXPECT_THAT_ERROR(S->readBytes(0, 1, Buffer), Succeeded());
285   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('A'));
286   EXPECT_THAT_ERROR(S->readBytes(9, 1, Buffer), Succeeded());
287   EXPECT_EQ(Buffer, ArrayRef<uint8_t>('J'));
288 }
289 
290 TEST(MappedBlockStreamTest, TestWriteBytesBreakBoundary) {
291   static uint8_t Data[] = {'0', '0', '0', '0', '0', '0', '0', '0', '0', '0'};
292   static uint8_t TestData[] = {'T', 'E', 'S', 'T', 'I', 'N', 'G', '.'};
293   static uint8_t Expected[] = {'T', 'E', 'S', 'N', 'I',
294                                'T', 'G', '.', '0', '0'};
295 
296   DiscontiguousStream F(BlocksAry, Data);
297   auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
298                                                    F, F.Allocator);
299   ArrayRef<uint8_t> Buffer;
300 
301   EXPECT_THAT_ERROR(S->writeBytes(0, TestData), Succeeded());
302   // First just compare the memory, then compare the result of reading the
303   // string out.
304   EXPECT_EQ(ArrayRef<uint8_t>(Data), ArrayRef<uint8_t>(Expected));
305 
306   EXPECT_THAT_ERROR(S->readBytes(0, 8, Buffer), Succeeded());
307   EXPECT_EQ(Buffer, ArrayRef<uint8_t>(TestData));
308 }
309 
310 TEST(MappedBlockStreamTest, TestWriteThenRead) {
311   std::vector<uint8_t> DataBytes(10);
312   MutableArrayRef<uint8_t> Data(DataBytes);
313   const uint32_t Blocks[] = {2, 1, 0, 6, 3, 4, 5, 7, 9, 8};
314 
315   DiscontiguousStream F(Blocks, Data);
316   auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
317                                                    F, F.Allocator);
318 
319   enum class MyEnum : uint32_t { Val1 = 2908234, Val2 = 120891234 };
320   using support::ulittle32_t;
321 
322   uint16_t u16[] = {31468, 0};
323   uint32_t u32[] = {890723408, 0};
324   MyEnum Enum[] = {MyEnum::Val1, MyEnum::Val2};
325   StringRef ZStr[] = {"Zero Str", ""};
326   StringRef FStr[] = {"Fixed Str", ""};
327   uint8_t byteArray0[] = {'1', '2'};
328   uint8_t byteArray1[] = {'0', '0'};
329   ArrayRef<uint8_t> byteArrayRef0(byteArray0);
330   ArrayRef<uint8_t> byteArrayRef1(byteArray1);
331   ArrayRef<uint8_t> byteArray[] = {byteArrayRef0, byteArrayRef1};
332   uint32_t intArr0[] = {890723408, 29082234};
333   uint32_t intArr1[] = {890723408, 29082234};
334   ArrayRef<uint32_t> intArray[] = {intArr0, intArr1};
335 
336   BinaryStreamReader Reader(*S);
337   BinaryStreamWriter Writer(*S);
338   EXPECT_THAT_ERROR(Writer.writeInteger(u16[0]), Succeeded());
339   EXPECT_THAT_ERROR(Reader.readInteger(u16[1]), Succeeded());
340   EXPECT_EQ(u16[0], u16[1]);
341   EXPECT_EQ(std::vector<uint8_t>({0, 0x7A, 0xEC, 0, 0, 0, 0, 0, 0, 0}),
342             DataBytes);
343 
344   Reader.setOffset(0);
345   Writer.setOffset(0);
346   ::memset(DataBytes.data(), 0, 10);
347   EXPECT_THAT_ERROR(Writer.writeInteger(u32[0]), Succeeded());
348   EXPECT_THAT_ERROR(Reader.readInteger(u32[1]), Succeeded());
349   EXPECT_EQ(u32[0], u32[1]);
350   EXPECT_EQ(std::vector<uint8_t>({0x17, 0x5C, 0x50, 0, 0, 0, 0x35, 0, 0, 0}),
351             DataBytes);
352 
353   Reader.setOffset(0);
354   Writer.setOffset(0);
355   ::memset(DataBytes.data(), 0, 10);
356   EXPECT_THAT_ERROR(Writer.writeEnum(Enum[0]), Succeeded());
357   EXPECT_THAT_ERROR(Reader.readEnum(Enum[1]), Succeeded());
358   EXPECT_EQ(Enum[0], Enum[1]);
359   EXPECT_EQ(std::vector<uint8_t>({0x2C, 0x60, 0x4A, 0, 0, 0, 0, 0, 0, 0}),
360             DataBytes);
361 
362   Reader.setOffset(0);
363   Writer.setOffset(0);
364   ::memset(DataBytes.data(), 0, 10);
365   EXPECT_THAT_ERROR(Writer.writeCString(ZStr[0]), Succeeded());
366   EXPECT_THAT_ERROR(Reader.readCString(ZStr[1]), Succeeded());
367   EXPECT_EQ(ZStr[0], ZStr[1]);
368   EXPECT_EQ(
369       std::vector<uint8_t>({'r', 'e', 'Z', ' ', 'S', 't', 'o', 'r', 0, 0}),
370       DataBytes);
371 
372   Reader.setOffset(0);
373   Writer.setOffset(0);
374   ::memset(DataBytes.data(), 0, 10);
375   EXPECT_THAT_ERROR(Writer.writeFixedString(FStr[0]), Succeeded());
376   EXPECT_THAT_ERROR(Reader.readFixedString(FStr[1], FStr[0].size()),
377                     Succeeded());
378   EXPECT_EQ(FStr[0], FStr[1]);
379   EXPECT_EQ(
380       std::vector<uint8_t>({'x', 'i', 'F', 'd', ' ', 'S', 'e', 't', 0, 'r'}),
381       DataBytes);
382 
383   Reader.setOffset(0);
384   Writer.setOffset(0);
385   ::memset(DataBytes.data(), 0, 10);
386   EXPECT_THAT_ERROR(Writer.writeArray(byteArray[0]), Succeeded());
387   EXPECT_THAT_ERROR(Reader.readArray(byteArray[1], byteArray[0].size()),
388                     Succeeded());
389   EXPECT_EQ(byteArray[0], byteArray[1]);
390   EXPECT_EQ(std::vector<uint8_t>({0, 0x32, 0x31, 0, 0, 0, 0, 0, 0, 0}),
391             DataBytes);
392 
393   Reader.setOffset(0);
394   Writer.setOffset(0);
395   ::memset(DataBytes.data(), 0, 10);
396   EXPECT_THAT_ERROR(Writer.writeArray(intArray[0]), Succeeded());
397   EXPECT_THAT_ERROR(Reader.readArray(intArray[1], intArray[0].size()),
398                     Succeeded());
399   EXPECT_EQ(intArray[0], intArray[1]);
400 }
401 
402 TEST(MappedBlockStreamTest, TestWriteContiguousStreamRef) {
403   std::vector<uint8_t> DestDataBytes(10);
404   MutableArrayRef<uint8_t> DestData(DestDataBytes);
405   const uint32_t DestBlocks[] = {2, 1, 0, 6, 3, 4, 5, 7, 9, 8};
406 
407   std::vector<uint8_t> SrcDataBytes(10);
408   MutableArrayRef<uint8_t> SrcData(SrcDataBytes);
409 
410   DiscontiguousStream F(DestBlocks, DestData);
411   auto DestStream = WritableMappedBlockStream::createStream(
412       F.block_size(), F.layout(), F, F.Allocator);
413 
414   // First write "Test Str" into the source stream.
415   MutableBinaryByteStream SourceStream(SrcData, little);
416   BinaryStreamWriter SourceWriter(SourceStream);
417   EXPECT_THAT_ERROR(SourceWriter.writeCString("Test Str"), Succeeded());
418   EXPECT_EQ(SrcDataBytes, std::vector<uint8_t>(
419                               {'T', 'e', 's', 't', ' ', 'S', 't', 'r', 0, 0}));
420 
421   // Then write the source stream into the dest stream.
422   BinaryStreamWriter DestWriter(*DestStream);
423   EXPECT_THAT_ERROR(DestWriter.writeStreamRef(SourceStream), Succeeded());
424   EXPECT_EQ(DestDataBytes, std::vector<uint8_t>(
425                                {'s', 'e', 'T', ' ', 'S', 't', 't', 'r', 0, 0}));
426 
427   // Then read the string back out of the dest stream.
428   StringRef Result;
429   BinaryStreamReader DestReader(*DestStream);
430   EXPECT_THAT_ERROR(DestReader.readCString(Result), Succeeded());
431   EXPECT_EQ(Result, "Test Str");
432 }
433 
434 TEST(MappedBlockStreamTest, TestWriteDiscontiguousStreamRef) {
435   std::vector<uint8_t> DestDataBytes(10);
436   MutableArrayRef<uint8_t> DestData(DestDataBytes);
437   const uint32_t DestBlocks[] = {2, 1, 0, 6, 3, 4, 5, 7, 9, 8};
438 
439   std::vector<uint8_t> SrcDataBytes(10);
440   MutableArrayRef<uint8_t> SrcData(SrcDataBytes);
441   const uint32_t SrcBlocks[] = {1, 0, 6, 3, 4, 5, 2, 7, 8, 9};
442 
443   DiscontiguousStream DestF(DestBlocks, DestData);
444   DiscontiguousStream SrcF(SrcBlocks, SrcData);
445 
446   auto Dest = WritableMappedBlockStream::createStream(
447       DestF.block_size(), DestF.layout(), DestF, DestF.Allocator);
448   auto Src = WritableMappedBlockStream::createStream(
449       SrcF.block_size(), SrcF.layout(), SrcF, SrcF.Allocator);
450 
451   // First write "Test Str" into the source stream.
452   BinaryStreamWriter SourceWriter(*Src);
453   EXPECT_THAT_ERROR(SourceWriter.writeCString("Test Str"), Succeeded());
454   EXPECT_EQ(SrcDataBytes, std::vector<uint8_t>(
455                               {'e', 'T', 't', 't', ' ', 'S', 's', 'r', 0, 0}));
456 
457   // Then write the source stream into the dest stream.
458   BinaryStreamWriter DestWriter(*Dest);
459   EXPECT_THAT_ERROR(DestWriter.writeStreamRef(*Src), Succeeded());
460   EXPECT_EQ(DestDataBytes, std::vector<uint8_t>(
461                                {'s', 'e', 'T', ' ', 'S', 't', 't', 'r', 0, 0}));
462 
463   // Then read the string back out of the dest stream.
464   StringRef Result;
465   BinaryStreamReader DestReader(*Dest);
466   EXPECT_THAT_ERROR(DestReader.readCString(Result), Succeeded());
467   EXPECT_EQ(Result, "Test Str");
468 }
469 
470 TEST(MappedBlockStreamTest, DataLivesAfterStreamDestruction) {
471   std::vector<uint8_t> DataBytes(10);
472   MutableArrayRef<uint8_t> Data(DataBytes);
473   const uint32_t Blocks[] = {2, 1, 0, 6, 3, 4, 5, 7, 9, 8};
474 
475   StringRef Str[] = {"Zero Str", ""};
476 
477   DiscontiguousStream F(Blocks, Data);
478   {
479     auto S = WritableMappedBlockStream::createStream(F.block_size(), F.layout(),
480                                                      F, F.Allocator);
481 
482     BinaryStreamReader Reader(*S);
483     BinaryStreamWriter Writer(*S);
484     ::memset(DataBytes.data(), 0, 10);
485     EXPECT_THAT_ERROR(Writer.writeCString(Str[0]), Succeeded());
486     EXPECT_THAT_ERROR(Reader.readCString(Str[1]), Succeeded());
487     EXPECT_EQ(Str[0], Str[1]);
488   }
489 
490   EXPECT_EQ(Str[0], Str[1]);
491 }
492 } // namespace
493 
494 MATCHER_P3(BlockIsFilledWith, Layout, BlockIndex, Byte, "succeeded") {
495   uint64_t Offset = msf::blockToOffset(BlockIndex, Layout.SB->BlockSize);
496   ArrayRef<uint8_t> BufferRef = makeArrayRef(arg);
497   BufferRef = BufferRef.slice(Offset, Layout.SB->BlockSize);
498   return llvm::all_of(BufferRef, [this](uint8_t B) { return B == Byte; });
499 }
500 
501 namespace {
502 TEST(MappedBlockStreamTest, CreateFpmStream) {
503   BumpPtrAllocator Allocator;
504   SuperBlock SB;
505   MSFLayout L;
506   L.SB = &SB;
507 
508   SB.FreeBlockMapBlock = 1;
509   SB.BlockSize = 4096;
510 
511   constexpr uint32_t NumFileBlocks = 4096 * 4;
512 
513   std::vector<uint8_t> MsfBuffer(NumFileBlocks * SB.BlockSize);
514   MutableBinaryByteStream MsfStream(MsfBuffer, llvm::support::little);
515 
516   SB.NumBlocks = NumFileBlocks;
517   auto FpmStream =
518       WritableMappedBlockStream::createFpmStream(L, MsfStream, Allocator);
519   // 4096 * 4 / 8 = 2048 bytes of FPM data is needed to describe 4096 * 4
520   // blocks.  This translates to 1 FPM block.
521   EXPECT_EQ(2048u, FpmStream->getLength());
522   EXPECT_EQ(1u, FpmStream->getStreamLayout().Blocks.size());
523   EXPECT_EQ(1u, FpmStream->getStreamLayout().Blocks[0]);
524   // All blocks from FPM1 should be 1 initialized, and all blocks from FPM2
525   // should be 0 initialized (since we requested the main FPM, not the alt FPM)
526   for (int I = 0; I < 4; ++I) {
527     EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 1 + I * SB.BlockSize, 0xFF));
528     EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 2 + I * SB.BlockSize, 0));
529   }
530 
531   ::memset(MsfBuffer.data(), 0, MsfBuffer.size());
532   FpmStream =
533       WritableMappedBlockStream::createFpmStream(L, MsfStream, Allocator, true);
534   // 4096 * 4 / 8 = 2048 bytes of FPM data is needed to describe 4096 * 4
535   // blocks.  This translates to 1 FPM block.
536   EXPECT_EQ(2048u, FpmStream->getLength());
537   EXPECT_EQ(1u, FpmStream->getStreamLayout().Blocks.size());
538   EXPECT_EQ(2u, FpmStream->getStreamLayout().Blocks[0]);
539   // All blocks from FPM2 should be 1 initialized, and all blocks from FPM1
540   // should be 0 initialized (since we requested the alt FPM, not the main FPM)
541   for (int I = 0; I < 4; ++I) {
542     EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 1 + I * SB.BlockSize, 0));
543     EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 2 + I * SB.BlockSize, 0xFF));
544   }
545 }
546 
547 } // end anonymous namespace
548