1 //===--- MemoryBuffer.cpp - Memory Buffer implementation ------------------===//
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 the MemoryBuffer interface.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "llvm/Support/MemoryBuffer.h"
14 #include "llvm/ADT/SmallString.h"
15 #include "llvm/Config/config.h"
16 #include "llvm/Support/Errc.h"
17 #include "llvm/Support/Errno.h"
18 #include "llvm/Support/FileSystem.h"
19 #include "llvm/Support/MathExtras.h"
20 #include "llvm/Support/Path.h"
21 #include "llvm/Support/Process.h"
22 #include "llvm/Support/Program.h"
23 #include "llvm/Support/SmallVectorMemoryBuffer.h"
24 #include <cassert>
25 #include <cerrno>
26 #include <cstring>
27 #include <new>
28 #include <sys/types.h>
29 #include <system_error>
30 #if !defined(_MSC_VER) && !defined(__MINGW32__)
31 #include <unistd.h>
32 #else
33 #include <io.h>
34 #endif
35 using namespace llvm;
36
37 //===----------------------------------------------------------------------===//
38 // MemoryBuffer implementation itself.
39 //===----------------------------------------------------------------------===//
40
~MemoryBuffer()41 MemoryBuffer::~MemoryBuffer() { }
42
43 /// init - Initialize this MemoryBuffer as a reference to externally allocated
44 /// memory, memory that we know is already null terminated.
init(const char * BufStart,const char * BufEnd,bool RequiresNullTerminator)45 void MemoryBuffer::init(const char *BufStart, const char *BufEnd,
46 bool RequiresNullTerminator) {
47 assert((!RequiresNullTerminator || BufEnd[0] == 0) &&
48 "Buffer is not null terminated!");
49 BufferStart = BufStart;
50 BufferEnd = BufEnd;
51 }
52
53 //===----------------------------------------------------------------------===//
54 // MemoryBufferMem implementation.
55 //===----------------------------------------------------------------------===//
56
57 /// CopyStringRef - Copies contents of a StringRef into a block of memory and
58 /// null-terminates it.
CopyStringRef(char * Memory,StringRef Data)59 static void CopyStringRef(char *Memory, StringRef Data) {
60 if (!Data.empty())
61 memcpy(Memory, Data.data(), Data.size());
62 Memory[Data.size()] = 0; // Null terminate string.
63 }
64
65 namespace {
66 struct NamedBufferAlloc {
67 const Twine &Name;
NamedBufferAlloc__anon59bbd2400111::NamedBufferAlloc68 NamedBufferAlloc(const Twine &Name) : Name(Name) {}
69 };
70 }
71
operator new(size_t N,const NamedBufferAlloc & Alloc)72 void *operator new(size_t N, const NamedBufferAlloc &Alloc) {
73 SmallString<256> NameBuf;
74 StringRef NameRef = Alloc.Name.toStringRef(NameBuf);
75
76 char *Mem = static_cast<char *>(operator new(N + NameRef.size() + 1));
77 CopyStringRef(Mem + N, NameRef);
78 return Mem;
79 }
80
81 namespace {
82 /// MemoryBufferMem - Named MemoryBuffer pointing to a block of memory.
83 template<typename MB>
84 class MemoryBufferMem : public MB {
85 public:
MemoryBufferMem(StringRef InputData,bool RequiresNullTerminator)86 MemoryBufferMem(StringRef InputData, bool RequiresNullTerminator) {
87 MemoryBuffer::init(InputData.begin(), InputData.end(),
88 RequiresNullTerminator);
89 }
90
91 /// Disable sized deallocation for MemoryBufferMem, because it has
92 /// tail-allocated data.
operator delete(void * p)93 void operator delete(void *p) { ::operator delete(p); }
94
getBufferIdentifier() const95 StringRef getBufferIdentifier() const override {
96 // The name is stored after the class itself.
97 return StringRef(reinterpret_cast<const char *>(this + 1));
98 }
99
getBufferKind() const100 MemoryBuffer::BufferKind getBufferKind() const override {
101 return MemoryBuffer::MemoryBuffer_Malloc;
102 }
103 };
104 }
105
106 template <typename MB>
107 static ErrorOr<std::unique_ptr<MB>>
108 getFileAux(const Twine &Filename, int64_t FileSize, uint64_t MapSize,
109 uint64_t Offset, bool RequiresNullTerminator, bool IsVolatile);
110
111 std::unique_ptr<MemoryBuffer>
getMemBuffer(StringRef InputData,StringRef BufferName,bool RequiresNullTerminator)112 MemoryBuffer::getMemBuffer(StringRef InputData, StringRef BufferName,
113 bool RequiresNullTerminator) {
114 auto *Ret = new (NamedBufferAlloc(BufferName))
115 MemoryBufferMem<MemoryBuffer>(InputData, RequiresNullTerminator);
116 return std::unique_ptr<MemoryBuffer>(Ret);
117 }
118
119 std::unique_ptr<MemoryBuffer>
getMemBuffer(MemoryBufferRef Ref,bool RequiresNullTerminator)120 MemoryBuffer::getMemBuffer(MemoryBufferRef Ref, bool RequiresNullTerminator) {
121 return std::unique_ptr<MemoryBuffer>(getMemBuffer(
122 Ref.getBuffer(), Ref.getBufferIdentifier(), RequiresNullTerminator));
123 }
124
125 static ErrorOr<std::unique_ptr<WritableMemoryBuffer>>
getMemBufferCopyImpl(StringRef InputData,const Twine & BufferName)126 getMemBufferCopyImpl(StringRef InputData, const Twine &BufferName) {
127 auto Buf = WritableMemoryBuffer::getNewUninitMemBuffer(InputData.size(), BufferName);
128 if (!Buf)
129 return make_error_code(errc::not_enough_memory);
130 memcpy(Buf->getBufferStart(), InputData.data(), InputData.size());
131 return std::move(Buf);
132 }
133
134 std::unique_ptr<MemoryBuffer>
getMemBufferCopy(StringRef InputData,const Twine & BufferName)135 MemoryBuffer::getMemBufferCopy(StringRef InputData, const Twine &BufferName) {
136 auto Buf = getMemBufferCopyImpl(InputData, BufferName);
137 if (Buf)
138 return std::move(*Buf);
139 return nullptr;
140 }
141
142 ErrorOr<std::unique_ptr<MemoryBuffer>>
getFileOrSTDIN(const Twine & Filename,int64_t FileSize,bool RequiresNullTerminator)143 MemoryBuffer::getFileOrSTDIN(const Twine &Filename, int64_t FileSize,
144 bool RequiresNullTerminator) {
145 SmallString<256> NameBuf;
146 StringRef NameRef = Filename.toStringRef(NameBuf);
147
148 if (NameRef == "-")
149 return getSTDIN();
150 return getFile(Filename, FileSize, RequiresNullTerminator);
151 }
152
153 ErrorOr<std::unique_ptr<MemoryBuffer>>
getFileSlice(const Twine & FilePath,uint64_t MapSize,uint64_t Offset,bool IsVolatile)154 MemoryBuffer::getFileSlice(const Twine &FilePath, uint64_t MapSize,
155 uint64_t Offset, bool IsVolatile) {
156 return getFileAux<MemoryBuffer>(FilePath, -1, MapSize, Offset, false,
157 IsVolatile);
158 }
159
160 //===----------------------------------------------------------------------===//
161 // MemoryBuffer::getFile implementation.
162 //===----------------------------------------------------------------------===//
163
164 namespace {
165 /// Memory maps a file descriptor using sys::fs::mapped_file_region.
166 ///
167 /// This handles converting the offset into a legal offset on the platform.
168 template<typename MB>
169 class MemoryBufferMMapFile : public MB {
170 sys::fs::mapped_file_region MFR;
171
getLegalMapOffset(uint64_t Offset)172 static uint64_t getLegalMapOffset(uint64_t Offset) {
173 return Offset & ~(sys::fs::mapped_file_region::alignment() - 1);
174 }
175
getLegalMapSize(uint64_t Len,uint64_t Offset)176 static uint64_t getLegalMapSize(uint64_t Len, uint64_t Offset) {
177 return Len + (Offset - getLegalMapOffset(Offset));
178 }
179
getStart(uint64_t Len,uint64_t Offset)180 const char *getStart(uint64_t Len, uint64_t Offset) {
181 return MFR.const_data() + (Offset - getLegalMapOffset(Offset));
182 }
183
184 public:
MemoryBufferMMapFile(bool RequiresNullTerminator,sys::fs::file_t FD,uint64_t Len,uint64_t Offset,std::error_code & EC)185 MemoryBufferMMapFile(bool RequiresNullTerminator, sys::fs::file_t FD, uint64_t Len,
186 uint64_t Offset, std::error_code &EC)
187 : MFR(FD, MB::Mapmode, getLegalMapSize(Len, Offset),
188 getLegalMapOffset(Offset), EC) {
189 if (!EC) {
190 const char *Start = getStart(Len, Offset);
191 MemoryBuffer::init(Start, Start + Len, RequiresNullTerminator);
192 }
193 }
194
195 /// Disable sized deallocation for MemoryBufferMMapFile, because it has
196 /// tail-allocated data.
operator delete(void * p)197 void operator delete(void *p) { ::operator delete(p); }
198
getBufferIdentifier() const199 StringRef getBufferIdentifier() const override {
200 // The name is stored after the class itself.
201 return StringRef(reinterpret_cast<const char *>(this + 1));
202 }
203
getBufferKind() const204 MemoryBuffer::BufferKind getBufferKind() const override {
205 return MemoryBuffer::MemoryBuffer_MMap;
206 }
207 };
208 }
209
210 static ErrorOr<std::unique_ptr<WritableMemoryBuffer>>
getMemoryBufferForStream(sys::fs::file_t FD,const Twine & BufferName)211 getMemoryBufferForStream(sys::fs::file_t FD, const Twine &BufferName) {
212 const ssize_t ChunkSize = 4096*4;
213 SmallString<ChunkSize> Buffer;
214 // Read into Buffer until we hit EOF.
215 for (;;) {
216 Buffer.reserve(Buffer.size() + ChunkSize);
217 Expected<size_t> ReadBytes = sys::fs::readNativeFile(
218 FD, makeMutableArrayRef(Buffer.end(), ChunkSize));
219 if (!ReadBytes)
220 return errorToErrorCode(ReadBytes.takeError());
221 if (*ReadBytes == 0)
222 break;
223 Buffer.set_size(Buffer.size() + *ReadBytes);
224 }
225
226 return getMemBufferCopyImpl(Buffer, BufferName);
227 }
228
229
230 ErrorOr<std::unique_ptr<MemoryBuffer>>
getFile(const Twine & Filename,int64_t FileSize,bool RequiresNullTerminator,bool IsVolatile)231 MemoryBuffer::getFile(const Twine &Filename, int64_t FileSize,
232 bool RequiresNullTerminator, bool IsVolatile) {
233 return getFileAux<MemoryBuffer>(Filename, FileSize, FileSize, 0,
234 RequiresNullTerminator, IsVolatile);
235 }
236
237 template <typename MB>
238 static ErrorOr<std::unique_ptr<MB>>
239 getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
240 uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator,
241 bool IsVolatile);
242
243 template <typename MB>
244 static ErrorOr<std::unique_ptr<MB>>
getFileAux(const Twine & Filename,int64_t FileSize,uint64_t MapSize,uint64_t Offset,bool RequiresNullTerminator,bool IsVolatile)245 getFileAux(const Twine &Filename, int64_t FileSize, uint64_t MapSize,
246 uint64_t Offset, bool RequiresNullTerminator, bool IsVolatile) {
247 Expected<sys::fs::file_t> FDOrErr =
248 sys::fs::openNativeFileForRead(Filename, sys::fs::OF_None);
249 if (!FDOrErr)
250 return errorToErrorCode(FDOrErr.takeError());
251 sys::fs::file_t FD = *FDOrErr;
252 auto Ret = getOpenFileImpl<MB>(FD, Filename, FileSize, MapSize, Offset,
253 RequiresNullTerminator, IsVolatile);
254 sys::fs::closeFile(FD);
255 return Ret;
256 }
257
258 ErrorOr<std::unique_ptr<WritableMemoryBuffer>>
getFile(const Twine & Filename,int64_t FileSize,bool IsVolatile)259 WritableMemoryBuffer::getFile(const Twine &Filename, int64_t FileSize,
260 bool IsVolatile) {
261 return getFileAux<WritableMemoryBuffer>(Filename, FileSize, FileSize, 0,
262 /*RequiresNullTerminator*/ false,
263 IsVolatile);
264 }
265
266 ErrorOr<std::unique_ptr<WritableMemoryBuffer>>
getFileSlice(const Twine & Filename,uint64_t MapSize,uint64_t Offset,bool IsVolatile)267 WritableMemoryBuffer::getFileSlice(const Twine &Filename, uint64_t MapSize,
268 uint64_t Offset, bool IsVolatile) {
269 return getFileAux<WritableMemoryBuffer>(Filename, -1, MapSize, Offset, false,
270 IsVolatile);
271 }
272
273 std::unique_ptr<WritableMemoryBuffer>
getNewUninitMemBuffer(size_t Size,const Twine & BufferName)274 WritableMemoryBuffer::getNewUninitMemBuffer(size_t Size, const Twine &BufferName) {
275 using MemBuffer = MemoryBufferMem<WritableMemoryBuffer>;
276 // Allocate space for the MemoryBuffer, the data and the name. It is important
277 // that MemoryBuffer and data are aligned so PointerIntPair works with them.
278 // TODO: Is 16-byte alignment enough? We copy small object files with large
279 // alignment expectations into this buffer.
280 SmallString<256> NameBuf;
281 StringRef NameRef = BufferName.toStringRef(NameBuf);
282 size_t AlignedStringLen = alignTo(sizeof(MemBuffer) + NameRef.size() + 1, 16);
283 size_t RealLen = AlignedStringLen + Size + 1;
284 char *Mem = static_cast<char*>(operator new(RealLen, std::nothrow));
285 if (!Mem)
286 return nullptr;
287
288 // The name is stored after the class itself.
289 CopyStringRef(Mem + sizeof(MemBuffer), NameRef);
290
291 // The buffer begins after the name and must be aligned.
292 char *Buf = Mem + AlignedStringLen;
293 Buf[Size] = 0; // Null terminate buffer.
294
295 auto *Ret = new (Mem) MemBuffer(StringRef(Buf, Size), true);
296 return std::unique_ptr<WritableMemoryBuffer>(Ret);
297 }
298
299 std::unique_ptr<WritableMemoryBuffer>
getNewMemBuffer(size_t Size,const Twine & BufferName)300 WritableMemoryBuffer::getNewMemBuffer(size_t Size, const Twine &BufferName) {
301 auto SB = WritableMemoryBuffer::getNewUninitMemBuffer(Size, BufferName);
302 if (!SB)
303 return nullptr;
304 memset(SB->getBufferStart(), 0, Size);
305 return SB;
306 }
307
shouldUseMmap(sys::fs::file_t FD,size_t FileSize,size_t MapSize,off_t Offset,bool RequiresNullTerminator,int PageSize,bool IsVolatile)308 static bool shouldUseMmap(sys::fs::file_t FD,
309 size_t FileSize,
310 size_t MapSize,
311 off_t Offset,
312 bool RequiresNullTerminator,
313 int PageSize,
314 bool IsVolatile) {
315 // mmap may leave the buffer without null terminator if the file size changed
316 // by the time the last page is mapped in, so avoid it if the file size is
317 // likely to change.
318 if (IsVolatile)
319 return false;
320
321 // We don't use mmap for small files because this can severely fragment our
322 // address space.
323 if (MapSize < 4 * 4096 || MapSize < (unsigned)PageSize)
324 return false;
325
326 if (!RequiresNullTerminator)
327 return true;
328
329 // If we don't know the file size, use fstat to find out. fstat on an open
330 // file descriptor is cheaper than stat on a random path.
331 // FIXME: this chunk of code is duplicated, but it avoids a fstat when
332 // RequiresNullTerminator = false and MapSize != -1.
333 if (FileSize == size_t(-1)) {
334 sys::fs::file_status Status;
335 if (sys::fs::status(FD, Status))
336 return false;
337 FileSize = Status.getSize();
338 }
339
340 // If we need a null terminator and the end of the map is inside the file,
341 // we cannot use mmap.
342 size_t End = Offset + MapSize;
343 assert(End <= FileSize);
344 if (End != FileSize)
345 return false;
346
347 // Don't try to map files that are exactly a multiple of the system page size
348 // if we need a null terminator.
349 if ((FileSize & (PageSize -1)) == 0)
350 return false;
351
352 #if defined(__CYGWIN__)
353 // Don't try to map files that are exactly a multiple of the physical page size
354 // if we need a null terminator.
355 // FIXME: We should reorganize again getPageSize() on Win32.
356 if ((FileSize & (4096 - 1)) == 0)
357 return false;
358 #endif
359
360 return true;
361 }
362
363 static ErrorOr<std::unique_ptr<WriteThroughMemoryBuffer>>
getReadWriteFile(const Twine & Filename,uint64_t FileSize,uint64_t MapSize,uint64_t Offset)364 getReadWriteFile(const Twine &Filename, uint64_t FileSize, uint64_t MapSize,
365 uint64_t Offset) {
366 Expected<sys::fs::file_t> FDOrErr = sys::fs::openNativeFileForReadWrite(
367 Filename, sys::fs::CD_OpenExisting, sys::fs::OF_None);
368 if (!FDOrErr)
369 return errorToErrorCode(FDOrErr.takeError());
370 sys::fs::file_t FD = *FDOrErr;
371
372 // Default is to map the full file.
373 if (MapSize == uint64_t(-1)) {
374 // If we don't know the file size, use fstat to find out. fstat on an open
375 // file descriptor is cheaper than stat on a random path.
376 if (FileSize == uint64_t(-1)) {
377 sys::fs::file_status Status;
378 std::error_code EC = sys::fs::status(FD, Status);
379 if (EC)
380 return EC;
381
382 // If this not a file or a block device (e.g. it's a named pipe
383 // or character device), we can't mmap it, so error out.
384 sys::fs::file_type Type = Status.type();
385 if (Type != sys::fs::file_type::regular_file &&
386 Type != sys::fs::file_type::block_file)
387 return make_error_code(errc::invalid_argument);
388
389 FileSize = Status.getSize();
390 }
391 MapSize = FileSize;
392 }
393
394 std::error_code EC;
395 std::unique_ptr<WriteThroughMemoryBuffer> Result(
396 new (NamedBufferAlloc(Filename))
397 MemoryBufferMMapFile<WriteThroughMemoryBuffer>(false, FD, MapSize,
398 Offset, EC));
399 if (EC)
400 return EC;
401 return std::move(Result);
402 }
403
404 ErrorOr<std::unique_ptr<WriteThroughMemoryBuffer>>
getFile(const Twine & Filename,int64_t FileSize)405 WriteThroughMemoryBuffer::getFile(const Twine &Filename, int64_t FileSize) {
406 return getReadWriteFile(Filename, FileSize, FileSize, 0);
407 }
408
409 /// Map a subrange of the specified file as a WritableMemoryBuffer.
410 ErrorOr<std::unique_ptr<WriteThroughMemoryBuffer>>
getFileSlice(const Twine & Filename,uint64_t MapSize,uint64_t Offset)411 WriteThroughMemoryBuffer::getFileSlice(const Twine &Filename, uint64_t MapSize,
412 uint64_t Offset) {
413 return getReadWriteFile(Filename, -1, MapSize, Offset);
414 }
415
416 template <typename MB>
417 static ErrorOr<std::unique_ptr<MB>>
getOpenFileImpl(sys::fs::file_t FD,const Twine & Filename,uint64_t FileSize,uint64_t MapSize,int64_t Offset,bool RequiresNullTerminator,bool IsVolatile)418 getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
419 uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator,
420 bool IsVolatile) {
421 static int PageSize = sys::Process::getPageSizeEstimate();
422
423 // Default is to map the full file.
424 if (MapSize == uint64_t(-1)) {
425 // If we don't know the file size, use fstat to find out. fstat on an open
426 // file descriptor is cheaper than stat on a random path.
427 if (FileSize == uint64_t(-1)) {
428 sys::fs::file_status Status;
429 std::error_code EC = sys::fs::status(FD, Status);
430 if (EC)
431 return EC;
432
433 // If this not a file or a block device (e.g. it's a named pipe
434 // or character device), we can't trust the size. Create the memory
435 // buffer by copying off the stream.
436 sys::fs::file_type Type = Status.type();
437 if (Type != sys::fs::file_type::regular_file &&
438 Type != sys::fs::file_type::block_file)
439 return getMemoryBufferForStream(FD, Filename);
440
441 FileSize = Status.getSize();
442 }
443 MapSize = FileSize;
444 }
445
446 if (shouldUseMmap(FD, FileSize, MapSize, Offset, RequiresNullTerminator,
447 PageSize, IsVolatile)) {
448 std::error_code EC;
449 std::unique_ptr<MB> Result(
450 new (NamedBufferAlloc(Filename)) MemoryBufferMMapFile<MB>(
451 RequiresNullTerminator, FD, MapSize, Offset, EC));
452 if (!EC)
453 return std::move(Result);
454 }
455
456 auto Buf = WritableMemoryBuffer::getNewUninitMemBuffer(MapSize, Filename);
457 if (!Buf) {
458 // Failed to create a buffer. The only way it can fail is if
459 // new(std::nothrow) returns 0.
460 return make_error_code(errc::not_enough_memory);
461 }
462
463 // Read until EOF, zero-initialize the rest.
464 MutableArrayRef<char> ToRead = Buf->getBuffer();
465 while (!ToRead.empty()) {
466 Expected<size_t> ReadBytes =
467 sys::fs::readNativeFileSlice(FD, ToRead, Offset);
468 if (!ReadBytes)
469 return errorToErrorCode(ReadBytes.takeError());
470 if (*ReadBytes == 0) {
471 std::memset(ToRead.data(), 0, ToRead.size());
472 break;
473 }
474 ToRead = ToRead.drop_front(*ReadBytes);
475 Offset += *ReadBytes;
476 }
477
478 return std::move(Buf);
479 }
480
481 ErrorOr<std::unique_ptr<MemoryBuffer>>
getOpenFile(sys::fs::file_t FD,const Twine & Filename,uint64_t FileSize,bool RequiresNullTerminator,bool IsVolatile)482 MemoryBuffer::getOpenFile(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
483 bool RequiresNullTerminator, bool IsVolatile) {
484 return getOpenFileImpl<MemoryBuffer>(FD, Filename, FileSize, FileSize, 0,
485 RequiresNullTerminator, IsVolatile);
486 }
487
488 ErrorOr<std::unique_ptr<MemoryBuffer>>
getOpenFileSlice(sys::fs::file_t FD,const Twine & Filename,uint64_t MapSize,int64_t Offset,bool IsVolatile)489 MemoryBuffer::getOpenFileSlice(sys::fs::file_t FD, const Twine &Filename, uint64_t MapSize,
490 int64_t Offset, bool IsVolatile) {
491 assert(MapSize != uint64_t(-1));
492 return getOpenFileImpl<MemoryBuffer>(FD, Filename, -1, MapSize, Offset, false,
493 IsVolatile);
494 }
495
getSTDIN()496 ErrorOr<std::unique_ptr<MemoryBuffer>> MemoryBuffer::getSTDIN() {
497 // Read in all of the data from stdin, we cannot mmap stdin.
498 //
499 // FIXME: That isn't necessarily true, we should try to mmap stdin and
500 // fallback if it fails.
501 sys::ChangeStdinToBinary();
502
503 return getMemoryBufferForStream(sys::fs::getStdinHandle(), "<stdin>");
504 }
505
506 ErrorOr<std::unique_ptr<MemoryBuffer>>
getFileAsStream(const Twine & Filename)507 MemoryBuffer::getFileAsStream(const Twine &Filename) {
508 Expected<sys::fs::file_t> FDOrErr =
509 sys::fs::openNativeFileForRead(Filename, sys::fs::OF_None);
510 if (!FDOrErr)
511 return errorToErrorCode(FDOrErr.takeError());
512 sys::fs::file_t FD = *FDOrErr;
513 ErrorOr<std::unique_ptr<MemoryBuffer>> Ret =
514 getMemoryBufferForStream(FD, Filename);
515 sys::fs::closeFile(FD);
516 return Ret;
517 }
518
getMemBufferRef() const519 MemoryBufferRef MemoryBuffer::getMemBufferRef() const {
520 StringRef Data = getBuffer();
521 StringRef Identifier = getBufferIdentifier();
522 return MemoryBufferRef(Data, Identifier);
523 }
524
~SmallVectorMemoryBuffer()525 SmallVectorMemoryBuffer::~SmallVectorMemoryBuffer() {}
526