xref: /llvm-project/llvm/unittests/Support/MemoryBufferTest.cpp (revision 46fab767882d48d2dd46a497baa3197bf9a98ab2)
1 //===- llvm/unittest/Support/MemoryBufferTest.cpp - MemoryBuffer tests ----===//
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 // This file implements unit tests for the MemoryBuffer support class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/Support/MemoryBuffer.h"
14 #include "llvm/Support/SmallVectorMemoryBuffer.h"
15 #include "llvm/ADT/ScopeExit.h"
16 #include "llvm/Support/FileSystem.h"
17 #include "llvm/Support/FileUtilities.h"
18 #include "llvm/Support/Process.h"
19 #include "llvm/Support/raw_ostream.h"
20 #include "llvm/Testing/Support/Error.h"
21 #include "gtest/gtest.h"
22 #if LLVM_ENABLE_THREADS
23 #include <thread>
24 #endif
25 #if LLVM_ON_UNIX
26 #include <unistd.h>
27 #endif
28 #if _WIN32
29 #include <windows.h>
30 #endif
31 
32 using namespace llvm;
33 
34 #define ASSERT_NO_ERROR(x)                                                     \
35   if (std::error_code ASSERT_NO_ERROR_ec = x) {                                \
36     SmallString<128> MessageStorage;                                           \
37     raw_svector_ostream Message(MessageStorage);                               \
38     Message << #x ": did not return errc::success.\n"                          \
39             << "error number: " << ASSERT_NO_ERROR_ec.value() << "\n"          \
40             << "error message: " << ASSERT_NO_ERROR_ec.message() << "\n";      \
41     GTEST_FATAL_FAILURE_(MessageStorage.c_str());                              \
42   } else {                                                                     \
43   }
44 
45 #define ASSERT_ERROR(x)                                                        \
46   if (!x) {                                                                    \
47     SmallString<128> MessageStorage;                                           \
48     raw_svector_ostream Message(MessageStorage);                               \
49     Message << #x ": did not return a failure error code.\n";                  \
50     GTEST_FATAL_FAILURE_(MessageStorage.c_str());                              \
51   }
52 
53 namespace {
54 
55 class MemoryBufferTest : public testing::Test {
56 protected:
57   MemoryBufferTest()
58   : data("this is some data")
59   { }
60 
61   void SetUp() override {}
62 
63   /// Common testing for different modes of getOpenFileSlice.
64   /// Creates a temporary file with known contents, and uses
65   /// MemoryBuffer::getOpenFileSlice to map it.
66   /// If \p Reopen is true, the file is closed after creating and reopened
67   /// anew before using MemoryBuffer.
68   void testGetOpenFileSlice(bool Reopen);
69 
70   typedef std::unique_ptr<MemoryBuffer> OwningBuffer;
71 
72   std::string data;
73 };
74 
75 TEST_F(MemoryBufferTest, get) {
76   // Default name and null-terminator flag
77   OwningBuffer MB1(MemoryBuffer::getMemBuffer(data));
78   EXPECT_NE(nullptr, MB1.get());
79 
80   // RequiresNullTerminator = false
81   OwningBuffer MB2(MemoryBuffer::getMemBuffer(data, "one", false));
82   EXPECT_NE(nullptr, MB2.get());
83 
84   // RequiresNullTerminator = true
85   OwningBuffer MB3(MemoryBuffer::getMemBuffer(data, "two", true));
86   EXPECT_NE(nullptr, MB3.get());
87 
88   // verify all 3 buffers point to the same address
89   EXPECT_EQ(MB1->getBufferStart(), MB2->getBufferStart());
90   EXPECT_EQ(MB2->getBufferStart(), MB3->getBufferStart());
91 
92   // verify the original data is unmodified after deleting the buffers
93   MB1.reset();
94   MB2.reset();
95   MB3.reset();
96   EXPECT_EQ("this is some data", data);
97 }
98 
99 TEST_F(MemoryBufferTest, getOpenFile) {
100   int FD;
101   SmallString<64> TestPath;
102   ASSERT_EQ(sys::fs::createTemporaryFile("MemoryBufferTest_getOpenFile", "temp",
103                                          FD, TestPath),
104             std::error_code());
105 
106   FileRemover Cleanup(TestPath);
107   raw_fd_ostream OF(FD, /*shouldClose*/ true);
108   OF << "12345678";
109   OF.close();
110 
111   {
112     Expected<sys::fs::file_t> File = sys::fs::openNativeFileForRead(TestPath);
113     ASSERT_THAT_EXPECTED(File, Succeeded());
114     auto OnExit =
115         make_scope_exit([&] { ASSERT_NO_ERROR(sys::fs::closeFile(*File)); });
116     ErrorOr<OwningBuffer> MB = MemoryBuffer::getOpenFile(*File, TestPath, 6);
117     ASSERT_NO_ERROR(MB.getError());
118     EXPECT_EQ("123456", MB.get()->getBuffer());
119   }
120   {
121     Expected<sys::fs::file_t> File = sys::fs::openNativeFileForWrite(
122         TestPath, sys::fs::CD_OpenExisting, sys::fs::OF_None);
123     ASSERT_THAT_EXPECTED(File, Succeeded());
124     auto OnExit =
125         make_scope_exit([&] { ASSERT_NO_ERROR(sys::fs::closeFile(*File)); });
126     ASSERT_ERROR(MemoryBuffer::getOpenFile(*File, TestPath, 6).getError());
127   }
128 }
129 
130 TEST_F(MemoryBufferTest, NullTerminator4K) {
131   // Test that a file with size that is a multiple of the page size can be null
132   // terminated correctly by MemoryBuffer.
133   int TestFD;
134   SmallString<64> TestPath;
135   sys::fs::createTemporaryFile("MemoryBufferTest_NullTerminator4K", "temp",
136                                TestFD, TestPath);
137   FileRemover Cleanup(TestPath);
138   raw_fd_ostream OF(TestFD, true, /*unbuffered=*/true);
139   for (unsigned i = 0; i < 4096 / 16; ++i) {
140     OF << "0123456789abcdef";
141   }
142   OF.close();
143 
144   ErrorOr<OwningBuffer> MB = MemoryBuffer::getFile(TestPath.c_str());
145   std::error_code EC = MB.getError();
146   ASSERT_FALSE(EC);
147 
148   const char *BufData = MB.get()->getBufferStart();
149   EXPECT_EQ('f', BufData[4095]);
150   EXPECT_EQ('\0', BufData[4096]);
151 }
152 
153 TEST_F(MemoryBufferTest, copy) {
154   // copy with no name
155   OwningBuffer MBC1(MemoryBuffer::getMemBufferCopy(data));
156   EXPECT_NE(nullptr, MBC1.get());
157 
158   // copy with a name
159   OwningBuffer MBC2(MemoryBuffer::getMemBufferCopy(data, "copy"));
160   EXPECT_NE(nullptr, MBC2.get());
161 
162   // verify the two copies do not point to the same place
163   EXPECT_NE(MBC1->getBufferStart(), MBC2->getBufferStart());
164 }
165 
166 #if LLVM_ENABLE_THREADS
167 TEST_F(MemoryBufferTest, createFromPipe) {
168   sys::fs::file_t pipes[2];
169 #if LLVM_ON_UNIX
170   ASSERT_EQ(::pipe(pipes), 0) << strerror(errno);
171 #else
172   ASSERT_TRUE(::CreatePipe(&pipes[0], &pipes[1], nullptr, 0))
173       << ::GetLastError();
174 #endif
175   auto ReadCloser = make_scope_exit([&] { sys::fs::closeFile(pipes[0]); });
176   std::thread Writer([&] {
177     auto WriteCloser = make_scope_exit([&] { sys::fs::closeFile(pipes[1]); });
178     for (unsigned i = 0; i < 5; ++i) {
179       std::this_thread::sleep_for(std::chrono::milliseconds(10));
180 #if LLVM_ON_UNIX
181       ASSERT_EQ(::write(pipes[1], "foo", 3), 3) << strerror(errno);
182 #else
183       DWORD Written;
184       ASSERT_TRUE(::WriteFile(pipes[1], "foo", 3, &Written, nullptr))
185           << ::GetLastError();
186       ASSERT_EQ(Written, 3u);
187 #endif
188     }
189   });
190   ErrorOr<OwningBuffer> MB =
191       MemoryBuffer::getOpenFile(pipes[0], "pipe", /*FileSize*/ -1);
192   Writer.join();
193   ASSERT_NO_ERROR(MB.getError());
194   EXPECT_EQ(MB.get()->getBuffer(), "foofoofoofoofoo");
195 }
196 #endif
197 
198 TEST_F(MemoryBufferTest, make_new) {
199   // 0-sized buffer
200   OwningBuffer Zero(WritableMemoryBuffer::getNewUninitMemBuffer(0));
201   EXPECT_NE(nullptr, Zero.get());
202 
203   // uninitialized buffer with no name
204   OwningBuffer One(WritableMemoryBuffer::getNewUninitMemBuffer(321));
205   EXPECT_NE(nullptr, One.get());
206 
207   // uninitialized buffer with name
208   OwningBuffer Two(WritableMemoryBuffer::getNewUninitMemBuffer(123, "bla"));
209   EXPECT_NE(nullptr, Two.get());
210 
211   // 0-initialized buffer with no name
212   OwningBuffer Three(WritableMemoryBuffer::getNewMemBuffer(321, data));
213   EXPECT_NE(nullptr, Three.get());
214   for (size_t i = 0; i < 321; ++i)
215     EXPECT_EQ(0, Three->getBufferStart()[0]);
216 
217   // 0-initialized buffer with name
218   OwningBuffer Four(WritableMemoryBuffer::getNewMemBuffer(123, "zeros"));
219   EXPECT_NE(nullptr, Four.get());
220   for (size_t i = 0; i < 123; ++i)
221     EXPECT_EQ(0, Four->getBufferStart()[0]);
222 
223   // uninitialized buffer with rollover size
224   OwningBuffer Five(
225       WritableMemoryBuffer::getNewUninitMemBuffer(SIZE_MAX, "huge"));
226   EXPECT_EQ(nullptr, Five.get());
227 }
228 
229 TEST_F(MemoryBufferTest, getNewAligned) {
230   auto CheckAlignment = [](size_t AlignmentValue) {
231     Align Alignment(AlignmentValue);
232     OwningBuffer AlignedBuffer =
233         WritableMemoryBuffer::getNewUninitMemBuffer(0, "", Alignment);
234     EXPECT_TRUE(isAddrAligned(Alignment, AlignedBuffer->getBufferStart()));
235   };
236 
237   // Test allocation with different alignments.
238   CheckAlignment(16);
239   CheckAlignment(32);
240   CheckAlignment(64);
241   CheckAlignment(128);
242   CheckAlignment(256);
243 }
244 
245 void MemoryBufferTest::testGetOpenFileSlice(bool Reopen) {
246   // Test that MemoryBuffer::getOpenFile works properly when no null
247   // terminator is requested and the size is large enough to trigger
248   // the usage of memory mapping.
249   int TestFD;
250   SmallString<64> TestPath;
251   // Create a temporary file and write data into it.
252   sys::fs::createTemporaryFile("prefix", "temp", TestFD, TestPath);
253   FileRemover Cleanup(TestPath);
254   // OF is responsible for closing the file; If the file is not
255   // reopened, it will be unbuffered so that the results are
256   // immediately visible through the fd.
257   raw_fd_ostream OF(TestFD, true, !Reopen);
258   for (int i = 0; i < 60000; ++i) {
259     OF << "0123456789";
260   }
261 
262   if (Reopen) {
263     OF.close();
264     EXPECT_FALSE(sys::fs::openFileForRead(TestPath.c_str(), TestFD));
265   }
266 
267   ErrorOr<OwningBuffer> Buf = MemoryBuffer::getOpenFileSlice(
268       sys::fs::convertFDToNativeFile(TestFD), TestPath.c_str(),
269       40000, // Size
270       80000  // Offset
271   );
272 
273   std::error_code EC = Buf.getError();
274   EXPECT_FALSE(EC);
275 
276   StringRef BufData = Buf.get()->getBuffer();
277   EXPECT_EQ(BufData.size(), 40000U);
278   EXPECT_EQ(BufData[0], '0');
279   EXPECT_EQ(BufData[9], '9');
280 }
281 
282 TEST_F(MemoryBufferTest, getOpenFileNoReopen) {
283   testGetOpenFileSlice(false);
284 }
285 
286 TEST_F(MemoryBufferTest, getOpenFileReopened) {
287   testGetOpenFileSlice(true);
288 }
289 
290 TEST_F(MemoryBufferTest, slice) {
291   // Create a file that is six pages long with different data on each page.
292   int FD;
293   SmallString<64> TestPath;
294   sys::fs::createTemporaryFile("MemoryBufferTest_Slice", "temp", FD, TestPath);
295   FileRemover Cleanup(TestPath);
296   raw_fd_ostream OF(FD, true, /*unbuffered=*/true);
297   for (unsigned i = 0; i < 0x2000 / 8; ++i) {
298     OF << "12345678";
299   }
300   for (unsigned i = 0; i < 0x2000 / 8; ++i) {
301     OF << "abcdefgh";
302   }
303   for (unsigned i = 0; i < 0x2000 / 8; ++i) {
304     OF << "ABCDEFGH";
305   }
306   OF.close();
307 
308   // Try offset of one page.
309   ErrorOr<OwningBuffer> MB = MemoryBuffer::getFileSlice(TestPath.str(),
310                                                         0x4000, 0x1000);
311   std::error_code EC = MB.getError();
312   ASSERT_FALSE(EC);
313   EXPECT_EQ(0x4000UL, MB.get()->getBufferSize());
314 
315   StringRef BufData = MB.get()->getBuffer();
316   EXPECT_TRUE(BufData.substr(0x0000,8).equals("12345678"));
317   EXPECT_TRUE(BufData.substr(0x0FF8,8).equals("12345678"));
318   EXPECT_TRUE(BufData.substr(0x1000,8).equals("abcdefgh"));
319   EXPECT_TRUE(BufData.substr(0x2FF8,8).equals("abcdefgh"));
320   EXPECT_TRUE(BufData.substr(0x3000,8).equals("ABCDEFGH"));
321   EXPECT_TRUE(BufData.substr(0x3FF8,8).equals("ABCDEFGH"));
322 
323   // Try non-page aligned.
324   ErrorOr<OwningBuffer> MB2 = MemoryBuffer::getFileSlice(TestPath.str(),
325                                                          0x3000, 0x0800);
326   EC = MB2.getError();
327   ASSERT_FALSE(EC);
328   EXPECT_EQ(0x3000UL, MB2.get()->getBufferSize());
329 
330   StringRef BufData2 = MB2.get()->getBuffer();
331   EXPECT_TRUE(BufData2.substr(0x0000,8).equals("12345678"));
332   EXPECT_TRUE(BufData2.substr(0x17F8,8).equals("12345678"));
333   EXPECT_TRUE(BufData2.substr(0x1800,8).equals("abcdefgh"));
334   EXPECT_TRUE(BufData2.substr(0x2FF8,8).equals("abcdefgh"));
335 }
336 
337 TEST_F(MemoryBufferTest, writableSlice) {
338   // Create a file initialized with some data
339   int FD;
340   SmallString<64> TestPath;
341   sys::fs::createTemporaryFile("MemoryBufferTest_WritableSlice", "temp", FD,
342                                TestPath);
343   FileRemover Cleanup(TestPath);
344   raw_fd_ostream OF(FD, true);
345   for (unsigned i = 0; i < 0x1000; ++i)
346     OF << "0123456789abcdef";
347   OF.close();
348 
349   {
350     auto MBOrError =
351         WritableMemoryBuffer::getFileSlice(TestPath.str(), 0x6000, 0x2000);
352     ASSERT_FALSE(MBOrError.getError());
353     // Write some data.  It should be mapped private, so that upon completion
354     // the original file contents are not modified.
355     WritableMemoryBuffer &MB = **MBOrError;
356     ASSERT_EQ(0x6000u, MB.getBufferSize());
357     char *Start = MB.getBufferStart();
358     ASSERT_EQ(MB.getBufferEnd(), MB.getBufferStart() + MB.getBufferSize());
359     ::memset(Start, 'x', MB.getBufferSize());
360   }
361 
362   auto MBOrError = MemoryBuffer::getFile(TestPath);
363   ASSERT_FALSE(MBOrError.getError());
364   auto &MB = **MBOrError;
365   ASSERT_EQ(0x10000u, MB.getBufferSize());
366   for (size_t i = 0; i < MB.getBufferSize(); i += 0x10)
367     EXPECT_EQ("0123456789abcdef", MB.getBuffer().substr(i, 0x10)) << "i: " << i;
368 }
369 
370 TEST_F(MemoryBufferTest, writeThroughFile) {
371   // Create a file initialized with some data
372   int FD;
373   SmallString<64> TestPath;
374   sys::fs::createTemporaryFile("MemoryBufferTest_WriteThrough", "temp", FD,
375                                TestPath);
376   FileRemover Cleanup(TestPath);
377   raw_fd_ostream OF(FD, true);
378   OF << "0123456789abcdef";
379   OF.close();
380   {
381     auto MBOrError = WriteThroughMemoryBuffer::getFile(TestPath);
382     ASSERT_FALSE(MBOrError.getError());
383     // Write some data.  It should be mapped readwrite, so that upon completion
384     // the original file contents are modified.
385     WriteThroughMemoryBuffer &MB = **MBOrError;
386     ASSERT_EQ(16u, MB.getBufferSize());
387     char *Start = MB.getBufferStart();
388     ASSERT_EQ(MB.getBufferEnd(), MB.getBufferStart() + MB.getBufferSize());
389     ::memset(Start, 'x', MB.getBufferSize());
390   }
391 
392   auto MBOrError = MemoryBuffer::getFile(TestPath);
393   ASSERT_FALSE(MBOrError.getError());
394   auto &MB = **MBOrError;
395   ASSERT_EQ(16u, MB.getBufferSize());
396   EXPECT_EQ("xxxxxxxxxxxxxxxx", MB.getBuffer());
397 }
398 
399 TEST_F(MemoryBufferTest, mmapVolatileNoNull) {
400   // Verify that `MemoryBuffer::getOpenFile` will use mmap when
401   // `RequiresNullTerminator = false`, `IsVolatile = true`, and the file is
402   // large enough to use mmap.
403   //
404   // This is done because Clang should use this mode to open module files, and
405   // falling back to malloc for them causes a huge memory usage increase.
406 
407   int FD;
408   SmallString<64> TestPath;
409   ASSERT_NO_ERROR(sys::fs::createTemporaryFile(
410       "MemoryBufferTest_mmapVolatileNoNull", "temp", FD, TestPath));
411   FileRemover Cleanup(TestPath);
412   raw_fd_ostream OF(FD, true);
413   // Create a file large enough to mmap. 4 pages should be enough.
414   unsigned PageSize = sys::Process::getPageSizeEstimate();
415   unsigned FileWrites = (PageSize * 4) / 8;
416   for (unsigned i = 0; i < FileWrites; ++i)
417     OF << "01234567";
418   OF.close();
419 
420   Expected<sys::fs::file_t> File = sys::fs::openNativeFileForRead(TestPath);
421   ASSERT_THAT_EXPECTED(File, Succeeded());
422   auto OnExit =
423       make_scope_exit([&] { ASSERT_NO_ERROR(sys::fs::closeFile(*File)); });
424 
425   auto MBOrError = MemoryBuffer::getOpenFile(*File, TestPath,
426       /*FileSize=*/-1, /*RequiresNullTerminator=*/false, /*IsVolatile=*/true);
427   ASSERT_NO_ERROR(MBOrError.getError())
428   OwningBuffer MB = std::move(*MBOrError);
429   EXPECT_EQ(MB->getBufferKind(), MemoryBuffer::MemoryBuffer_MMap);
430   EXPECT_EQ(MB->getBufferSize(), std::size_t(FileWrites * 8));
431   EXPECT_TRUE(MB->getBuffer().startswith("01234567"));
432 }
433 
434 // Test that SmallVector without a null terminator gets one.
435 TEST(SmallVectorMemoryBufferTest, WithoutNullTerminatorRequiresNullTerminator) {
436   SmallString<0> Data("some data");
437 
438   SmallVectorMemoryBuffer MB(std::move(Data),
439                              /*RequiresNullTerminator=*/true);
440   EXPECT_EQ(MB.getBufferSize(), 9u);
441   EXPECT_EQ(MB.getBufferEnd()[0], '\0');
442 }
443 
444 // Test that SmallVector with a null terminator keeps it.
445 TEST(SmallVectorMemoryBufferTest, WithNullTerminatorRequiresNullTerminator) {
446   SmallString<0> Data("some data");
447   Data.push_back('\0');
448   Data.pop_back();
449 
450   SmallVectorMemoryBuffer MB(std::move(Data),
451                              /*RequiresNullTerminator=*/true);
452   EXPECT_EQ(MB.getBufferSize(), 9u);
453   EXPECT_EQ(MB.getBufferEnd()[0], '\0');
454 }
455 
456 } // namespace
457