#include "llvm/Support/MemoryBuffer.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallString.h"
-#include "llvm/System/Errno.h"
-#include "llvm/System/Path.h"
-#include "llvm/System/Process.h"
-#include "llvm/System/Program.h"
+#include "llvm/Config/config.h"
+#include "llvm/Support/Errno.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Process.h"
+#include "llvm/Support/Program.h"
+#include "llvm/Support/system_error.h"
#include <cassert>
+#include <cerrno>
#include <cstdio>
#include <cstring>
-#include <cerrno>
-#include <sys/types.h>
+#include <new>
#include <sys/stat.h>
+#include <sys/types.h>
#if !defined(_MSC_VER) && !defined(__MINGW32__)
#include <unistd.h>
-#include <sys/uio.h>
#else
#include <io.h>
+// Simplistic definitinos of these macros for use in getOpenFile.
+#ifndef S_ISREG
+#define S_ISREG(x) (1)
+#endif
+#ifndef S_ISBLK
+#define S_ISBLK(x) (0)
+#endif
#endif
-#include <fcntl.h>
using namespace llvm;
//===----------------------------------------------------------------------===//
// MemoryBuffer implementation itself.
//===----------------------------------------------------------------------===//
-MemoryBuffer::~MemoryBuffer() {
- if (MustDeleteBuffer)
- free((void*)BufferStart);
-}
-
-/// initCopyOf - Initialize this source buffer with a copy of the specified
-/// memory range. We make the copy so that we can null terminate it
-/// successfully.
-void MemoryBuffer::initCopyOf(const char *BufStart, const char *BufEnd) {
- size_t Size = BufEnd-BufStart;
- BufferStart = (char *)malloc(Size+1);
- BufferEnd = BufferStart+Size;
- memcpy(const_cast<char*>(BufferStart), BufStart, Size);
- *const_cast<char*>(BufferEnd) = 0; // Null terminate buffer.
- MustDeleteBuffer = true;
-}
+MemoryBuffer::~MemoryBuffer() { }
/// init - Initialize this MemoryBuffer as a reference to externally allocated
/// memory, memory that we know is already null terminated.
-void MemoryBuffer::init(const char *BufStart, const char *BufEnd) {
- assert(BufEnd[0] == 0 && "Buffer is not null terminated!");
+void MemoryBuffer::init(const char *BufStart, const char *BufEnd,
+ bool RequiresNullTerminator) {
+ assert((!RequiresNullTerminator || BufEnd[0] == 0) &&
+ "Buffer is not null terminated!");
BufferStart = BufStart;
BufferEnd = BufEnd;
- MustDeleteBuffer = false;
}
//===----------------------------------------------------------------------===//
// MemoryBufferMem implementation.
//===----------------------------------------------------------------------===//
+/// CopyStringRef - Copies contents of a StringRef into a block of memory and
+/// null-terminates it.
+static void CopyStringRef(char *Memory, StringRef Data) {
+ memcpy(Memory, Data.data(), Data.size());
+ Memory[Data.size()] = 0; // Null terminate string.
+}
+
namespace {
+struct NamedBufferAlloc {
+ StringRef Name;
+ NamedBufferAlloc(StringRef Name) : Name(Name) {}
+};
+}
+
+void *operator new(size_t N, const NamedBufferAlloc &Alloc) {
+ char *Mem = static_cast<char *>(operator new(N + Alloc.Name.size() + 1));
+ CopyStringRef(Mem + N, Alloc.Name);
+ return Mem;
+}
+
+namespace {
+/// MemoryBufferMem - Named MemoryBuffer pointing to a block of memory.
class MemoryBufferMem : public MemoryBuffer {
- std::string FileID;
public:
- MemoryBufferMem(const char *Start, const char *End, StringRef FID,
- bool Copy = false)
- : FileID(FID) {
- if (!Copy)
- init(Start, End);
- else
- initCopyOf(Start, End);
+ MemoryBufferMem(StringRef InputData, bool RequiresNullTerminator) {
+ init(InputData.begin(), InputData.end(), RequiresNullTerminator);
}
-
- virtual const char *getBufferIdentifier() const {
- return FileID.c_str();
+
+ virtual const char *getBufferIdentifier() const LLVM_OVERRIDE {
+ // The name is stored after the class itself.
+ return reinterpret_cast<const char*>(this + 1);
+ }
+
+ virtual BufferKind getBufferKind() const LLVM_OVERRIDE {
+ return MemoryBuffer_Malloc;
}
};
}
/// getMemBuffer - Open the specified memory range as a MemoryBuffer. Note
-/// that EndPtr[0] must be a null byte and be accessible!
-MemoryBuffer *MemoryBuffer::getMemBuffer(const char *StartPtr,
- const char *EndPtr,
- const char *BufferName) {
- return new MemoryBufferMem(StartPtr, EndPtr, BufferName);
+/// that InputData must be a null terminated if RequiresNullTerminator is true!
+MemoryBuffer *MemoryBuffer::getMemBuffer(StringRef InputData,
+ StringRef BufferName,
+ bool RequiresNullTerminator) {
+ return new (NamedBufferAlloc(BufferName))
+ MemoryBufferMem(InputData, RequiresNullTerminator);
}
/// getMemBufferCopy - Open the specified memory range as a MemoryBuffer,
/// copying the contents and taking ownership of it. This has no requirements
/// on EndPtr[0].
-MemoryBuffer *MemoryBuffer::getMemBufferCopy(const char *StartPtr,
- const char *EndPtr,
- const char *BufferName) {
- return new MemoryBufferMem(StartPtr, EndPtr, BufferName, true);
+MemoryBuffer *MemoryBuffer::getMemBufferCopy(StringRef InputData,
+ StringRef BufferName) {
+ MemoryBuffer *Buf = getNewUninitMemBuffer(InputData.size(), BufferName);
+ if (!Buf) return 0;
+ memcpy(const_cast<char*>(Buf->getBufferStart()), InputData.data(),
+ InputData.size());
+ return Buf;
}
/// getNewUninitMemBuffer - Allocate a new MemoryBuffer of the specified size
-/// that is completely initialized to zeros. Note that the caller should
-/// initialize the memory allocated by this method. The memory is owned by
-/// the MemoryBuffer object.
+/// that is not initialized. Note that the caller should initialize the
+/// memory allocated by this method. The memory is owned by the MemoryBuffer
+/// object.
MemoryBuffer *MemoryBuffer::getNewUninitMemBuffer(size_t Size,
StringRef BufferName) {
- char *Buf = (char *)malloc(Size+1);
- if (!Buf) return 0;
- Buf[Size] = 0;
- MemoryBufferMem *SB = new MemoryBufferMem(Buf, Buf+Size, BufferName);
- // The memory for this buffer is owned by the MemoryBuffer.
- SB->MustDeleteBuffer = true;
- return SB;
+ // Allocate space for the MemoryBuffer, the data and the name. It is important
+ // that MemoryBuffer and data are aligned so PointerIntPair works with them.
+ size_t AlignedStringLen =
+ RoundUpToAlignment(sizeof(MemoryBufferMem) + BufferName.size() + 1,
+ sizeof(void*)); // TODO: Is sizeof(void*) enough?
+ size_t RealLen = AlignedStringLen + Size + 1;
+ char *Mem = static_cast<char*>(operator new(RealLen, std::nothrow));
+ if (!Mem) return 0;
+
+ // The name is stored after the class itself.
+ CopyStringRef(Mem + sizeof(MemoryBufferMem), BufferName);
+
+ // The buffer begins after the name and must be aligned.
+ char *Buf = Mem + AlignedStringLen;
+ Buf[Size] = 0; // Null terminate buffer.
+
+ return new (Mem) MemoryBufferMem(StringRef(Buf, Size), true);
}
/// getNewMemBuffer - Allocate a new MemoryBuffer of the specified size that
/// is completely initialized to zeros. Note that the caller should
/// initialize the memory allocated by this method. The memory is owned by
/// the MemoryBuffer object.
-MemoryBuffer *MemoryBuffer::getNewMemBuffer(size_t Size,
- const char *BufferName) {
+MemoryBuffer *MemoryBuffer::getNewMemBuffer(size_t Size, StringRef BufferName) {
MemoryBuffer *SB = getNewUninitMemBuffer(Size, BufferName);
if (!SB) return 0;
- memset(const_cast<char*>(SB->getBufferStart()), 0, Size+1);
+ memset(const_cast<char*>(SB->getBufferStart()), 0, Size);
return SB;
}
/// if the Filename is "-". If an error occurs, this returns null and fills
/// in *ErrStr with a reason. If stdin is empty, this API (unlike getSTDIN)
/// returns an empty buffer.
-MemoryBuffer *MemoryBuffer::getFileOrSTDIN(StringRef Filename,
- std::string *ErrStr,
- int64_t FileSize,
- struct stat *FileInfo) {
+error_code MemoryBuffer::getFileOrSTDIN(StringRef Filename,
+ OwningPtr<MemoryBuffer> &result,
+ int64_t FileSize) {
if (Filename == "-")
- return getSTDIN();
- return getFile(Filename, ErrStr, FileSize, FileInfo);
+ return getSTDIN(result);
+ return getFile(Filename, result, FileSize);
}
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
namespace {
-/// MemoryBufferMMapFile - This represents a file that was mapped in with the
-/// sys::Path::MapInFilePages method. When destroyed, it calls the
-/// sys::Path::UnMapFilePages method.
+/// \brief Memory maps a file descriptor using sys::fs::mapped_file_region.
+///
+/// This handles converting the offset into a legal offset on the platform.
class MemoryBufferMMapFile : public MemoryBuffer {
- std::string Filename;
-public:
- MemoryBufferMMapFile(StringRef filename, const char *Pages, uint64_t Size)
- : Filename(filename) {
- init(Pages, Pages+Size);
+ sys::fs::mapped_file_region MFR;
+
+ static uint64_t getLegalMapOffset(uint64_t Offset) {
+ return Offset & ~(sys::fs::mapped_file_region::alignment() - 1);
}
-
- virtual const char *getBufferIdentifier() const {
- return Filename.c_str();
+
+ static uint64_t getLegalMapSize(uint64_t Len, uint64_t Offset) {
+ return Len + (Offset - getLegalMapOffset(Offset));
}
-
- ~MemoryBufferMMapFile() {
- sys::Path::UnMapFilePages(getBufferStart(), getBufferSize());
+
+ const char *getStart(uint64_t Len, uint64_t Offset) {
+ return MFR.const_data() + (Offset - getLegalMapOffset(Offset));
}
-};
-/// FileCloser - RAII object to make sure an FD gets closed properly.
-class FileCloser {
- int FD;
public:
- FileCloser(int FD) : FD(FD) {}
- ~FileCloser() { ::close(FD); }
+ MemoryBufferMMapFile(bool RequiresNullTerminator, int FD, uint64_t Len,
+ uint64_t Offset, error_code EC)
+ : MFR(FD, false, sys::fs::mapped_file_region::readonly,
+ getLegalMapSize(Len, Offset), getLegalMapOffset(Offset), EC) {
+ if (!EC) {
+ const char *Start = getStart(Len, Offset);
+ init(Start, Start + Len, RequiresNullTerminator);
+ }
+ }
+
+ virtual const char *getBufferIdentifier() const LLVM_OVERRIDE {
+ // The name is stored after the class itself.
+ return reinterpret_cast<const char *>(this + 1);
+ }
+
+ virtual BufferKind getBufferKind() const LLVM_OVERRIDE {
+ return MemoryBuffer_MMap;
+ }
};
}
-MemoryBuffer *MemoryBuffer::getFile(StringRef Filename, std::string *ErrStr,
- int64_t FileSize, struct stat *FileInfo) {
- int OpenFlags = 0;
-#ifdef O_BINARY
- OpenFlags |= O_BINARY; // Open input file in binary mode on win32.
-#endif
+static error_code getMemoryBufferForStream(int FD,
+ StringRef BufferName,
+ OwningPtr<MemoryBuffer> &result) {
+ const ssize_t ChunkSize = 4096*4;
+ SmallString<ChunkSize> Buffer;
+ ssize_t ReadBytes;
+ // Read into Buffer until we hit EOF.
+ do {
+ Buffer.reserve(Buffer.size() + ChunkSize);
+ ReadBytes = read(FD, Buffer.end(), ChunkSize);
+ if (ReadBytes == -1) {
+ if (errno == EINTR) continue;
+ return error_code(errno, posix_category());
+ }
+ Buffer.set_size(Buffer.size() + ReadBytes);
+ } while (ReadBytes != 0);
+
+ result.reset(MemoryBuffer::getMemBufferCopy(Buffer, BufferName));
+ return error_code::success();
+}
+
+error_code MemoryBuffer::getFile(StringRef Filename,
+ OwningPtr<MemoryBuffer> &result,
+ int64_t FileSize,
+ bool RequiresNullTerminator) {
+ // Ensure the path is null terminated.
SmallString<256> PathBuf(Filename.begin(), Filename.end());
- int FD = ::open(PathBuf.c_str(), O_RDONLY|OpenFlags);
- if (FD == -1) {
- if (ErrStr) *ErrStr = sys::StrError();
- return 0;
- }
- FileCloser FC(FD); // Close FD on return.
-
+ return MemoryBuffer::getFile(PathBuf.c_str(), result, FileSize,
+ RequiresNullTerminator);
+}
+
+static error_code getOpenFileImpl(int FD, const char *Filename,
+ OwningPtr<MemoryBuffer> &Result,
+ uint64_t FileSize, uint64_t MapSize,
+ int64_t Offset, bool RequiresNullTerminator);
+
+error_code MemoryBuffer::getFile(const char *Filename,
+ OwningPtr<MemoryBuffer> &result,
+ int64_t FileSize,
+ bool RequiresNullTerminator) {
+ int FD;
+ error_code EC = sys::fs::openFileForRead(Filename, FD);
+ if (EC)
+ return EC;
+
+ error_code ret = getOpenFileImpl(FD, Filename, result, FileSize, FileSize, 0,
+ RequiresNullTerminator);
+ close(FD);
+ return ret;
+}
+
+static bool shouldUseMmap(int FD,
+ size_t FileSize,
+ size_t MapSize,
+ off_t Offset,
+ bool RequiresNullTerminator,
+ int PageSize) {
+ // We don't use mmap for small files because this can severely fragment our
+ // address space.
+ if (MapSize < 4 * 4096 || MapSize < (unsigned)PageSize)
+ return false;
+
+ if (!RequiresNullTerminator)
+ return true;
+
+
// If we don't know the file size, use fstat to find out. fstat on an open
// file descriptor is cheaper than stat on a random path.
- if (FileSize == -1 || FileInfo) {
- struct stat MyFileInfo;
- struct stat *FileInfoPtr = FileInfo? FileInfo : &MyFileInfo;
-
- // TODO: This should use fstat64 when available.
- if (fstat(FD, FileInfoPtr) == -1) {
- if (ErrStr) *ErrStr = sys::StrError();
- return 0;
- }
- FileSize = FileInfoPtr->st_size;
+ // FIXME: this chunk of code is duplicated, but it avoids a fstat when
+ // RequiresNullTerminator = false and MapSize != -1.
+ if (FileSize == size_t(-1)) {
+ sys::fs::file_status Status;
+ error_code EC = sys::fs::status(FD, Status);
+ if (EC)
+ return EC;
+ FileSize = Status.getSize();
}
-
-
- // If the file is large, try to use mmap to read it in. We don't use mmap
- // for small files, because this can severely fragment our address space. Also
- // don't try to map files that are exactly a multiple of the system page size,
- // as the file would not have the required null terminator.
- //
- // FIXME: Can we just mmap an extra page in the latter case?
- if (FileSize >= 4096*4 &&
- (FileSize & (sys::Process::GetPageSize()-1)) != 0) {
- if (const char *Pages = sys::Path::MapInFilePages(FD, FileSize)) {
- // Close the file descriptor, now that the whole file is in memory.
- return new MemoryBufferMMapFile(Filename, Pages, FileSize);
+
+ // If we need a null terminator and the end of the map is inside the file,
+ // we cannot use mmap.
+ size_t End = Offset + MapSize;
+ assert(End <= FileSize);
+ if (End != FileSize)
+ return false;
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+ // Don't peek the next page if file is multiple of *physical* pagesize(4k)
+ // but is not multiple of AllocationGranularity(64k),
+ // when a null terminator is required.
+ // FIXME: It's not good to hardcode 4096 here. dwPageSize shows 4096.
+ if ((FileSize & (4096 - 1)) == 0)
+ return false;
+#endif
+
+ // Don't try to map files that are exactly a multiple of the system page size
+ // if we need a null terminator.
+ if ((FileSize & (PageSize -1)) == 0)
+ return false;
+
+ return true;
+}
+
+static error_code getOpenFileImpl(int FD, const char *Filename,
+ OwningPtr<MemoryBuffer> &result,
+ uint64_t FileSize, uint64_t MapSize,
+ int64_t Offset, bool RequiresNullTerminator) {
+ static int PageSize = sys::process::get_self()->page_size();
+
+ // Default is to map the full file.
+ if (MapSize == uint64_t(-1)) {
+ // If we don't know the file size, use fstat to find out. fstat on an open
+ // file descriptor is cheaper than stat on a random path.
+ if (FileSize == uint64_t(-1)) {
+ sys::fs::file_status Status;
+ error_code EC = sys::fs::status(FD, Status);
+ if (EC)
+ return EC;
+
+ // If this not a file or a block device (e.g. it's a named pipe
+ // or character device), we can't trust the size. Create the memory
+ // buffer by copying off the stream.
+ sys::fs::file_type Type = Status.type();
+ if (Type != sys::fs::file_type::regular_file &&
+ Type != sys::fs::file_type::block_file)
+ return getMemoryBufferForStream(FD, Filename, result);
+
+ FileSize = Status.getSize();
}
+ MapSize = FileSize;
+ }
+
+ if (shouldUseMmap(FD, FileSize, MapSize, Offset, RequiresNullTerminator,
+ PageSize)) {
+ error_code EC;
+ result.reset(new (NamedBufferAlloc(Filename)) MemoryBufferMMapFile(
+ RequiresNullTerminator, FD, MapSize, Offset, EC));
+ if (!EC)
+ return error_code::success();
}
- MemoryBuffer *Buf = MemoryBuffer::getNewUninitMemBuffer(FileSize, Filename);
+ MemoryBuffer *Buf = MemoryBuffer::getNewUninitMemBuffer(MapSize, Filename);
if (!Buf) {
- // Failed to create a buffer.
- if (ErrStr) *ErrStr = "could not allocate buffer";
- return 0;
+ // Failed to create a buffer. The only way it can fail is if
+ // new(std::nothrow) returns 0.
+ return make_error_code(errc::not_enough_memory);
}
OwningPtr<MemoryBuffer> SB(Buf);
char *BufPtr = const_cast<char*>(SB->getBufferStart());
- size_t BytesLeft = FileSize;
+ size_t BytesLeft = MapSize;
+#ifndef HAVE_PREAD
+ if (lseek(FD, Offset, SEEK_SET) == -1)
+ return error_code(errno, posix_category());
+#endif
+
while (BytesLeft) {
+#ifdef HAVE_PREAD
+ ssize_t NumRead = ::pread(FD, BufPtr, BytesLeft, MapSize-BytesLeft+Offset);
+#else
ssize_t NumRead = ::read(FD, BufPtr, BytesLeft);
+#endif
if (NumRead == -1) {
if (errno == EINTR)
continue;
// Error while reading.
- if (ErrStr) *ErrStr = sys::StrError();
- return 0;
- } else if (NumRead == 0) {
- // We hit EOF early, truncate and terminate buffer.
- Buf->BufferEnd = BufPtr;
- *BufPtr = 0;
- return SB.take();
+ return error_code(errno, posix_category());
+ }
+ if (NumRead == 0) {
+ assert(0 && "We got inaccurate FileSize value or fstat reported an "
+ "invalid file size.");
+ *BufPtr = '\0'; // null-terminate at the actual size.
+ break;
}
BytesLeft -= NumRead;
BufPtr += NumRead;
}
- return SB.take();
+ result.swap(SB);
+ return error_code::success();
}
-//===----------------------------------------------------------------------===//
-// MemoryBuffer::getSTDIN implementation.
-//===----------------------------------------------------------------------===//
-
-namespace {
-class STDINBufferFile : public MemoryBuffer {
-public:
- virtual const char *getBufferIdentifier() const {
- return "<stdin>";
- }
-};
+error_code MemoryBuffer::getOpenFile(int FD, const char *Filename,
+ OwningPtr<MemoryBuffer> &Result,
+ uint64_t FileSize,
+ bool RequiresNullTerminator) {
+ return getOpenFileImpl(FD, Filename, Result, FileSize, FileSize, 0,
+ RequiresNullTerminator);
}
-MemoryBuffer *MemoryBuffer::getSTDIN() {
- char Buffer[4096*4];
+error_code MemoryBuffer::getOpenFileSlice(int FD, const char *Filename,
+ OwningPtr<MemoryBuffer> &Result,
+ uint64_t MapSize, int64_t Offset) {
+ return getOpenFileImpl(FD, Filename, Result, -1, MapSize, Offset, false);
+}
- std::vector<char> FileData;
+//===----------------------------------------------------------------------===//
+// MemoryBuffer::getSTDIN implementation.
+//===----------------------------------------------------------------------===//
+error_code MemoryBuffer::getSTDIN(OwningPtr<MemoryBuffer> &result) {
// Read in all of the data from stdin, we cannot mmap stdin.
//
// FIXME: That isn't necessarily true, we should try to mmap stdin and
// fallback if it fails.
- sys::Program::ChangeStdinToBinary();
- size_t ReadBytes;
- do {
- ReadBytes = fread(Buffer, sizeof(char), sizeof(Buffer), stdin);
- FileData.insert(FileData.end(), Buffer, Buffer+ReadBytes);
- } while (ReadBytes == sizeof(Buffer));
-
- FileData.push_back(0); // &FileData[Size] is invalid. So is &*FileData.end().
- size_t Size = FileData.size();
- MemoryBuffer *B = new STDINBufferFile();
- B->initCopyOf(&FileData[0], &FileData[Size-1]);
- return B;
+ sys::ChangeStdinToBinary();
+
+ return getMemoryBufferForStream(0, "<stdin>", result);
}
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