#include "llvm/Support/MemoryBuffer.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallString.h"
-#include "llvm/Support/MathExtras.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;
//===----------------------------------------------------------------------===//
/// 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;
}
Memory[Data.size()] = 0; // Null terminate string.
}
-/// GetNamedBuffer - Allocates a new MemoryBuffer with Name copied after it.
-template <typename T>
-static T* GetNamedBuffer(StringRef Buffer, StringRef Name) {
- char *Mem = static_cast<char*>(operator new(sizeof(T) + Name.size() + 1));
- CopyStringRef(Mem + sizeof(T), Name);
- return new (Mem) T(Buffer);
+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 {
public:
- MemoryBufferMem(StringRef InputData) {
- init(InputData.begin(), InputData.end());
+ MemoryBufferMem(StringRef InputData, bool RequiresNullTerminator) {
+ init(InputData.begin(), InputData.end(), RequiresNullTerminator);
}
- virtual const char *getBufferIdentifier() const {
+ 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!
+/// that InputData must be a null terminated if RequiresNullTerminator is true!
MemoryBuffer *MemoryBuffer::getMemBuffer(StringRef InputData,
- StringRef BufferName) {
- return GetNamedBuffer<MemoryBufferMem>(InputData, BufferName);
+ StringRef BufferName,
+ bool RequiresNullTerminator) {
+ return new (NamedBufferAlloc(BufferName))
+ MemoryBufferMem(InputData, RequiresNullTerminator);
}
/// getMemBufferCopy - Open the specified memory range as a MemoryBuffer,
char *Buf = Mem + AlignedStringLen;
Buf[Size] = 0; // Null terminate buffer.
- return new (Mem) MemoryBufferMem(StringRef(Buf, Size));
+ return new (Mem) MemoryBufferMem(StringRef(Buf, Size), true);
}
/// getNewMemBuffer - Allocate a new MemoryBuffer of the specified size that
/// 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,
- error_code &ec,
- int64_t FileSize) {
+error_code MemoryBuffer::getFileOrSTDIN(StringRef Filename,
+ OwningPtr<MemoryBuffer> &result,
+ int64_t FileSize) {
if (Filename == "-")
- return getSTDIN(ec);
- return getFile(Filename, ec, FileSize);
-}
-
-MemoryBuffer *MemoryBuffer::getFileOrSTDIN(const char *Filename,
- error_code &ec,
- int64_t FileSize) {
- if (strcmp(Filename, "-") == 0)
- return getSTDIN(ec);
- return getFile(Filename, ec, FileSize);
+ 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.
-class MemoryBufferMMapFile : public MemoryBufferMem {
-public:
- MemoryBufferMMapFile(StringRef Buffer)
- : MemoryBufferMem(Buffer) { }
+/// \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 {
+ sys::fs::mapped_file_region MFR;
+
+ static uint64_t getLegalMapOffset(uint64_t Offset) {
+ return Offset & ~(sys::fs::mapped_file_region::alignment() - 1);
+ }
- ~MemoryBufferMMapFile() {
- sys::Path::UnMapFilePages(getBufferStart(), getBufferSize());
+ static uint64_t getLegalMapSize(uint64_t Len, uint64_t Offset) {
+ return Len + (Offset - getLegalMapOffset(Offset));
+ }
+
+ 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:
- explicit 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, error_code &ec,
- int64_t FileSize) {
+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());
- return MemoryBuffer::getFile(PathBuf.c_str(), ec, FileSize);
+ return MemoryBuffer::getFile(PathBuf.c_str(), result, FileSize,
+ RequiresNullTerminator);
}
-MemoryBuffer *MemoryBuffer::getFile(const char *Filename, error_code &ec,
- int64_t FileSize) {
- int OpenFlags = O_RDONLY;
-#ifdef O_BINARY
- OpenFlags |= O_BINARY; // Open input file in binary mode on win32.
-#endif
- int FD = ::open(Filename, OpenFlags);
- if (FD == -1) {
- ec = error_code(errno, posix_category());
- return 0;
- }
+static error_code getOpenFileImpl(int FD, const char *Filename,
+ OwningPtr<MemoryBuffer> &Result,
+ uint64_t FileSize, uint64_t MapSize,
+ int64_t Offset, bool RequiresNullTerminator);
- return getOpenFile(FD, Filename, ec, FileSize);
+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;
}
-MemoryBuffer *MemoryBuffer::getOpenFile(int FD, const char *Filename,
- error_code &ec, int64_t FileSize) {
- FileCloser FC(FD); // Close FD on return.
+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) {
- struct stat FileInfo;
- // TODO: This should use fstat64 when available.
- if (fstat(FD, &FileInfo) == -1) {
- ec = error_code(errno, posix_category());
- return 0;
- }
- FileSize = FileInfo.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 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
- // 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)) {
- return GetNamedBuffer<MemoryBufferMMapFile>(StringRef(Pages, FileSize),
- Filename);
+ // 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;
}
- MemoryBuffer *Buf = MemoryBuffer::getNewUninitMemBuffer(FileSize, Filename);
+ 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(MapSize, Filename);
if (!Buf) {
// Failed to create a buffer. The only way it can fail is if
// new(std::nothrow) returns 0.
- ec = make_error_code(errc::not_enough_memory);
- return 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.
- ec = error_code(errno, posix_category());
- 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();
+}
+
+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);
+}
+
+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);
}
//===----------------------------------------------------------------------===//
// MemoryBuffer::getSTDIN implementation.
//===----------------------------------------------------------------------===//
-MemoryBuffer *MemoryBuffer::getSTDIN(error_code &ec) {
+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();
-
- 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(0, Buffer.end(), ChunkSize);
- if (ReadBytes == -1) {
- if (errno == EINTR) continue;
- ec = error_code(errno, posix_category());
- return 0;
- }
- Buffer.set_size(Buffer.size() + ReadBytes);
- } while (ReadBytes != 0);
+ sys::ChangeStdinToBinary();
- return getMemBufferCopy(Buffer, "<stdin>");
+ return getMemoryBufferForStream(0, "<stdin>", result);
}
projects / oota-llvm.git / blobdiff