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