xref: /llvm-project/llvm/unittests/Support/MemoryBufferTest.cpp (revision 51d7398f630cee2239cf0c624d0fa60c63c7375a)
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/raw_ostream.h"
18 #include "llvm/Testing/Support/Error.h"
19 #include "gtest/gtest.h"
20 
21 using namespace llvm;
22 
23 #define ASSERT_NO_ERROR(x)                                                     \
24   if (std::error_code ASSERT_NO_ERROR_ec = x) {                                \
25     SmallString<128> MessageStorage;                                           \
26     raw_svector_ostream Message(MessageStorage);                               \
27     Message << #x ": did not return errc::success.\n"                          \
28             << "error number: " << ASSERT_NO_ERROR_ec.value() << "\n"          \
29             << "error message: " << ASSERT_NO_ERROR_ec.message() << "\n";      \
30     GTEST_FATAL_FAILURE_(MessageStorage.c_str());                              \
31   } else {                                                                     \
32   }
33 
34 #define ASSERT_ERROR(x)                                                        \
35   if (!x) {                                                                    \
36     SmallString<128> MessageStorage;                                           \
37     raw_svector_ostream Message(MessageStorage);                               \
38     Message << #x ": did not return a failure error code.\n";                  \
39     GTEST_FATAL_FAILURE_(MessageStorage.c_str());                              \
40   }
41 
42 namespace {
43 
44 class MemoryBufferTest : public testing::Test {
45 protected:
46   MemoryBufferTest()
47   : data("this is some data")
48   { }
49 
50   void SetUp() override {}
51 
52   /// Common testing for different modes of getOpenFileSlice.
53   /// Creates a temporary file with known contents, and uses
54   /// MemoryBuffer::getOpenFileSlice to map it.
55   /// If \p Reopen is true, the file is closed after creating and reopened
56   /// anew before using MemoryBuffer.
57   void testGetOpenFileSlice(bool Reopen);
58 
59   typedef std::unique_ptr<MemoryBuffer> OwningBuffer;
60 
61   std::string data;
62 };
63 
64 TEST_F(MemoryBufferTest, get) {
65   // Default name and null-terminator flag
66   OwningBuffer MB1(MemoryBuffer::getMemBuffer(data));
67   EXPECT_TRUE(nullptr != MB1.get());
68 
69   // RequiresNullTerminator = false
70   OwningBuffer MB2(MemoryBuffer::getMemBuffer(data, "one", false));
71   EXPECT_TRUE(nullptr != MB2.get());
72 
73   // RequiresNullTerminator = true
74   OwningBuffer MB3(MemoryBuffer::getMemBuffer(data, "two", true));
75   EXPECT_TRUE(nullptr != MB3.get());
76 
77   // verify all 3 buffers point to the same address
78   EXPECT_EQ(MB1->getBufferStart(), MB2->getBufferStart());
79   EXPECT_EQ(MB2->getBufferStart(), MB3->getBufferStart());
80 
81   // verify the original data is unmodified after deleting the buffers
82   MB1.reset();
83   MB2.reset();
84   MB3.reset();
85   EXPECT_EQ("this is some data", data);
86 }
87 
88 TEST_F(MemoryBufferTest, getOpenFile) {
89   int FD;
90   SmallString<64> TestPath;
91   ASSERT_EQ(sys::fs::createTemporaryFile("MemoryBufferTest_getOpenFile", "temp",
92                                          FD, TestPath),
93             std::error_code());
94 
95   FileRemover Cleanup(TestPath);
96   raw_fd_ostream OF(FD, /*shouldClose*/ true);
97   OF << "12345678";
98   OF.close();
99 
100   {
101     Expected<sys::fs::file_t> File = sys::fs::openNativeFileForRead(TestPath);
102     ASSERT_THAT_EXPECTED(File, Succeeded());
103     auto OnExit =
104         make_scope_exit([&] { ASSERT_NO_ERROR(sys::fs::closeFile(*File)); });
105     ErrorOr<OwningBuffer> MB = MemoryBuffer::getOpenFile(*File, TestPath, 6);
106     ASSERT_NO_ERROR(MB.getError());
107     EXPECT_EQ("123456", MB.get()->getBuffer());
108   }
109   {
110     Expected<sys::fs::file_t> File = sys::fs::openNativeFileForWrite(
111         TestPath, sys::fs::CD_OpenExisting, sys::fs::OF_None);
112     ASSERT_THAT_EXPECTED(File, Succeeded());
113     auto OnExit =
114         make_scope_exit([&] { ASSERT_NO_ERROR(sys::fs::closeFile(*File)); });
115     ASSERT_ERROR(MemoryBuffer::getOpenFile(*File, TestPath, 6).getError());
116   }
117 }
118 
119 TEST_F(MemoryBufferTest, NullTerminator4K) {
120   // Test that a file with size that is a multiple of the page size can be null
121   // terminated correctly by MemoryBuffer.
122   int TestFD;
123   SmallString<64> TestPath;
124   sys::fs::createTemporaryFile("MemoryBufferTest_NullTerminator4K", "temp",
125                                TestFD, TestPath);
126   FileRemover Cleanup(TestPath);
127   raw_fd_ostream OF(TestFD, true, /*unbuffered=*/true);
128   for (unsigned i = 0; i < 4096 / 16; ++i) {
129     OF << "0123456789abcdef";
130   }
131   OF.close();
132 
133   ErrorOr<OwningBuffer> MB = MemoryBuffer::getFile(TestPath.c_str());
134   std::error_code EC = MB.getError();
135   ASSERT_FALSE(EC);
136 
137   const char *BufData = MB.get()->getBufferStart();
138   EXPECT_EQ('f', BufData[4095]);
139   EXPECT_EQ('\0', BufData[4096]);
140 }
141 
142 TEST_F(MemoryBufferTest, copy) {
143   // copy with no name
144   OwningBuffer MBC1(MemoryBuffer::getMemBufferCopy(data));
145   EXPECT_TRUE(nullptr != MBC1.get());
146 
147   // copy with a name
148   OwningBuffer MBC2(MemoryBuffer::getMemBufferCopy(data, "copy"));
149   EXPECT_TRUE(nullptr != MBC2.get());
150 
151   // verify the two copies do not point to the same place
152   EXPECT_NE(MBC1->getBufferStart(), MBC2->getBufferStart());
153 }
154 
155 TEST_F(MemoryBufferTest, make_new) {
156   // 0-sized buffer
157   OwningBuffer Zero(WritableMemoryBuffer::getNewUninitMemBuffer(0));
158   EXPECT_TRUE(nullptr != Zero.get());
159 
160   // uninitialized buffer with no name
161   OwningBuffer One(WritableMemoryBuffer::getNewUninitMemBuffer(321));
162   EXPECT_TRUE(nullptr != One.get());
163 
164   // uninitialized buffer with name
165   OwningBuffer Two(WritableMemoryBuffer::getNewUninitMemBuffer(123, "bla"));
166   EXPECT_TRUE(nullptr != Two.get());
167 
168   // 0-initialized buffer with no name
169   OwningBuffer Three(WritableMemoryBuffer::getNewMemBuffer(321, data));
170   EXPECT_TRUE(nullptr != Three.get());
171   for (size_t i = 0; i < 321; ++i)
172     EXPECT_EQ(0, Three->getBufferStart()[0]);
173 
174   // 0-initialized buffer with name
175   OwningBuffer Four(WritableMemoryBuffer::getNewMemBuffer(123, "zeros"));
176   EXPECT_TRUE(nullptr != Four.get());
177   for (size_t i = 0; i < 123; ++i)
178     EXPECT_EQ(0, Four->getBufferStart()[0]);
179 }
180 
181 void MemoryBufferTest::testGetOpenFileSlice(bool Reopen) {
182   // Test that MemoryBuffer::getOpenFile works properly when no null
183   // terminator is requested and the size is large enough to trigger
184   // the usage of memory mapping.
185   int TestFD;
186   SmallString<64> TestPath;
187   // Create a temporary file and write data into it.
188   sys::fs::createTemporaryFile("prefix", "temp", TestFD, TestPath);
189   FileRemover Cleanup(TestPath);
190   // OF is responsible for closing the file; If the file is not
191   // reopened, it will be unbuffered so that the results are
192   // immediately visible through the fd.
193   raw_fd_ostream OF(TestFD, true, !Reopen);
194   for (int i = 0; i < 60000; ++i) {
195     OF << "0123456789";
196   }
197 
198   if (Reopen) {
199     OF.close();
200     EXPECT_FALSE(sys::fs::openFileForRead(TestPath.c_str(), TestFD));
201   }
202 
203   ErrorOr<OwningBuffer> Buf = MemoryBuffer::getOpenFileSlice(
204       sys::fs::convertFDToNativeFile(TestFD), TestPath.c_str(),
205       40000, // Size
206       80000  // Offset
207   );
208 
209   std::error_code EC = Buf.getError();
210   EXPECT_FALSE(EC);
211 
212   StringRef BufData = Buf.get()->getBuffer();
213   EXPECT_EQ(BufData.size(), 40000U);
214   EXPECT_EQ(BufData[0], '0');
215   EXPECT_EQ(BufData[9], '9');
216 }
217 
218 TEST_F(MemoryBufferTest, getOpenFileNoReopen) {
219   testGetOpenFileSlice(false);
220 }
221 
222 TEST_F(MemoryBufferTest, getOpenFileReopened) {
223   testGetOpenFileSlice(true);
224 }
225 
226 TEST_F(MemoryBufferTest, reference) {
227   OwningBuffer MB(MemoryBuffer::getMemBuffer(data));
228   MemoryBufferRef MBR(*MB);
229 
230   EXPECT_EQ(MB->getBufferStart(), MBR.getBufferStart());
231   EXPECT_EQ(MB->getBufferIdentifier(), MBR.getBufferIdentifier());
232 }
233 
234 TEST_F(MemoryBufferTest, slice) {
235   // Create a file that is six pages long with different data on each page.
236   int FD;
237   SmallString<64> TestPath;
238   sys::fs::createTemporaryFile("MemoryBufferTest_Slice", "temp", FD, TestPath);
239   FileRemover Cleanup(TestPath);
240   raw_fd_ostream OF(FD, true, /*unbuffered=*/true);
241   for (unsigned i = 0; i < 0x2000 / 8; ++i) {
242     OF << "12345678";
243   }
244   for (unsigned i = 0; i < 0x2000 / 8; ++i) {
245     OF << "abcdefgh";
246   }
247   for (unsigned i = 0; i < 0x2000 / 8; ++i) {
248     OF << "ABCDEFGH";
249   }
250   OF.close();
251 
252   // Try offset of one page.
253   ErrorOr<OwningBuffer> MB = MemoryBuffer::getFileSlice(TestPath.str(),
254                                                         0x4000, 0x1000);
255   std::error_code EC = MB.getError();
256   ASSERT_FALSE(EC);
257   EXPECT_EQ(0x4000UL, MB.get()->getBufferSize());
258 
259   StringRef BufData = MB.get()->getBuffer();
260   EXPECT_TRUE(BufData.substr(0x0000,8).equals("12345678"));
261   EXPECT_TRUE(BufData.substr(0x0FF8,8).equals("12345678"));
262   EXPECT_TRUE(BufData.substr(0x1000,8).equals("abcdefgh"));
263   EXPECT_TRUE(BufData.substr(0x2FF8,8).equals("abcdefgh"));
264   EXPECT_TRUE(BufData.substr(0x3000,8).equals("ABCDEFGH"));
265   EXPECT_TRUE(BufData.substr(0x3FF8,8).equals("ABCDEFGH"));
266 
267   // Try non-page aligned.
268   ErrorOr<OwningBuffer> MB2 = MemoryBuffer::getFileSlice(TestPath.str(),
269                                                          0x3000, 0x0800);
270   EC = MB2.getError();
271   ASSERT_FALSE(EC);
272   EXPECT_EQ(0x3000UL, MB2.get()->getBufferSize());
273 
274   StringRef BufData2 = MB2.get()->getBuffer();
275   EXPECT_TRUE(BufData2.substr(0x0000,8).equals("12345678"));
276   EXPECT_TRUE(BufData2.substr(0x17F8,8).equals("12345678"));
277   EXPECT_TRUE(BufData2.substr(0x1800,8).equals("abcdefgh"));
278   EXPECT_TRUE(BufData2.substr(0x2FF8,8).equals("abcdefgh"));
279 }
280 
281 TEST_F(MemoryBufferTest, writableSlice) {
282   // Create a file initialized with some data
283   int FD;
284   SmallString<64> TestPath;
285   sys::fs::createTemporaryFile("MemoryBufferTest_WritableSlice", "temp", FD,
286                                TestPath);
287   FileRemover Cleanup(TestPath);
288   raw_fd_ostream OF(FD, true);
289   for (unsigned i = 0; i < 0x1000; ++i)
290     OF << "0123456789abcdef";
291   OF.close();
292 
293   {
294     auto MBOrError =
295         WritableMemoryBuffer::getFileSlice(TestPath.str(), 0x6000, 0x2000);
296     ASSERT_FALSE(MBOrError.getError());
297     // Write some data.  It should be mapped private, so that upon completion
298     // the original file contents are not modified.
299     WritableMemoryBuffer &MB = **MBOrError;
300     ASSERT_EQ(0x6000u, MB.getBufferSize());
301     char *Start = MB.getBufferStart();
302     ASSERT_EQ(MB.getBufferEnd(), MB.getBufferStart() + MB.getBufferSize());
303     ::memset(Start, 'x', MB.getBufferSize());
304   }
305 
306   auto MBOrError = MemoryBuffer::getFile(TestPath);
307   ASSERT_FALSE(MBOrError.getError());
308   auto &MB = **MBOrError;
309   ASSERT_EQ(0x10000u, MB.getBufferSize());
310   for (size_t i = 0; i < MB.getBufferSize(); i += 0x10)
311     EXPECT_EQ("0123456789abcdef", MB.getBuffer().substr(i, 0x10)) << "i: " << i;
312 }
313 
314 TEST_F(MemoryBufferTest, writeThroughFile) {
315   // Create a file initialized with some data
316   int FD;
317   SmallString<64> TestPath;
318   sys::fs::createTemporaryFile("MemoryBufferTest_WriteThrough", "temp", FD,
319                                TestPath);
320   FileRemover Cleanup(TestPath);
321   raw_fd_ostream OF(FD, true);
322   OF << "0123456789abcdef";
323   OF.close();
324   {
325     auto MBOrError = WriteThroughMemoryBuffer::getFile(TestPath);
326     ASSERT_FALSE(MBOrError.getError());
327     // Write some data.  It should be mapped readwrite, so that upon completion
328     // the original file contents are modified.
329     WriteThroughMemoryBuffer &MB = **MBOrError;
330     ASSERT_EQ(16u, MB.getBufferSize());
331     char *Start = MB.getBufferStart();
332     ASSERT_EQ(MB.getBufferEnd(), MB.getBufferStart() + MB.getBufferSize());
333     ::memset(Start, 'x', MB.getBufferSize());
334   }
335 
336   auto MBOrError = MemoryBuffer::getFile(TestPath);
337   ASSERT_FALSE(MBOrError.getError());
338   auto &MB = **MBOrError;
339   ASSERT_EQ(16u, MB.getBufferSize());
340   EXPECT_EQ("xxxxxxxxxxxxxxxx", MB.getBuffer());
341 }
342 }
343