1 files changed, 297 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/MemoryBuffer.cpp b/contrib/llvm/lib/Support/MemoryBuffer.cpp
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+++ b/contrib/llvm/lib/Support/MemoryBuffer.cpp
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+//===--- MemoryBuffer.cpp - Memory Buffer implementation ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements the MemoryBuffer interface.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/System/Errno.h"
+#include "llvm/System/Path.h"
+#include "llvm/System/Process.h"
+#include "llvm/System/Program.h"
+#include <cassert>
+#include <cstdio>
+#include <cstring>
+#include <cerrno>
+#include <sys/types.h>
+#include <sys/stat.h>
+#if !defined(_MSC_VER) && !defined(__MINGW32__)
+#include <unistd.h>
+#include <sys/uio.h>
+#else
+#include <io.h>
+#endif
+#include <fcntl.h>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// MemoryBuffer implementation itself.
+//===----------------------------------------------------------------------===//
+
+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!");
+  BufferStart = BufStart;
+  BufferEnd = BufEnd;
+}
+
+//===----------------------------------------------------------------------===//
+// 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.
+}
+
+/// 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 {
+/// MemoryBufferMem - Named MemoryBuffer pointing to a block of memory.
+class MemoryBufferMem : public MemoryBuffer {
+public:
+  MemoryBufferMem(StringRef InputData) {
+    init(InputData.begin(), InputData.end());
+  }
+
+  virtual const char *getBufferIdentifier() const {
+     // The name is stored after the class itself.
+    return reinterpret_cast<const char*>(this + 1);
+  }
+};
+}
+
+/// getMemBuffer - Open the specified memory range as a MemoryBuffer.  Note
+/// that EndPtr[0] must be a null byte and be accessible!
+MemoryBuffer *MemoryBuffer::getMemBuffer(StringRef InputData,
+                                         StringRef BufferName) {
+  return GetNamedBuffer<MemoryBufferMem>(InputData, BufferName);
+}
+
+/// 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(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 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) {
+  // 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));
+}
+
+/// 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, StringRef BufferName) {
+  MemoryBuffer *SB = getNewUninitMemBuffer(Size, BufferName);
+  if (!SB) return 0;
+  memset(const_cast<char*>(SB->getBufferStart()), 0, Size);
+  return SB;
+}
+
+
+/// getFileOrSTDIN - Open the specified file as a MemoryBuffer, or open stdin
+/// 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) {
+  if (Filename == "-")
+    return getSTDIN(ErrStr);
+  return getFile(Filename, ErrStr, FileSize, FileInfo);
+}
+
+MemoryBuffer *MemoryBuffer::getFileOrSTDIN(const char *Filename,
+                                           std::string *ErrStr,
+                                           int64_t FileSize,
+                                           struct stat *FileInfo) {
+  if (strcmp(Filename, "-") == 0)
+    return getSTDIN(ErrStr);
+  return getFile(Filename, ErrStr, FileSize, FileInfo);
+}
+
+//===----------------------------------------------------------------------===//
+// MemoryBuffer::getFile implementation.
+//===----------------------------------------------------------------------===//
+
+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) { }
+
+  ~MemoryBufferMMapFile() {
+    sys::Path::UnMapFilePages(getBufferStart(), getBufferSize());
+  }
+};
+
+/// 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); }
+};
+}
+
+MemoryBuffer *MemoryBuffer::getFile(StringRef Filename, std::string *ErrStr,
+                                    int64_t FileSize, struct stat *FileInfo) {
+  SmallString<256> PathBuf(Filename.begin(), Filename.end());
+  return MemoryBuffer::getFile(PathBuf.c_str(), ErrStr, FileSize, FileInfo);
+}
+
+MemoryBuffer *MemoryBuffer::getFile(const char *Filename, std::string *ErrStr,
+                                    int64_t FileSize, struct stat *FileInfo) {
+  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) {
+    if (ErrStr) *ErrStr = sys::StrError();
+    return 0;
+  }
+  FileCloser FC(FD); // Close FD on return.
+  
+  // 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;
+  }
+  
+  
+  // 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);
+    }
+  }
+
+  MemoryBuffer *Buf = MemoryBuffer::getNewUninitMemBuffer(FileSize, Filename);
+  if (!Buf) {
+    // Failed to create a buffer.
+    if (ErrStr) *ErrStr = "could not allocate buffer";
+    return 0;
+  }
+
+  OwningPtr<MemoryBuffer> SB(Buf);
+  char *BufPtr = const_cast<char*>(SB->getBufferStart());
+
+  size_t BytesLeft = FileSize;
+  while (BytesLeft) {
+    ssize_t NumRead = ::read(FD, BufPtr, BytesLeft);
+    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();
+    }
+    BytesLeft -= NumRead;
+    BufPtr += NumRead;
+  }
+
+  return SB.take();
+}
+
+//===----------------------------------------------------------------------===//
+// MemoryBuffer::getSTDIN implementation.
+//===----------------------------------------------------------------------===//
+
+MemoryBuffer *MemoryBuffer::getSTDIN(std::string *ErrStr) {
+  // 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;
+      if (ErrStr) *ErrStr = sys::StrError();
+      return 0;
+    }
+    Buffer.set_size(Buffer.size() + ReadBytes);
+  } while (ReadBytes != 0);
+
+  return getMemBufferCopy(Buffer, "<stdin>");
+}