Shuffle StandardPasses.cpp into VMCore; add it to CMake.

[oota-llvm.git] / lib / Support / MemoryBuffer.cpp

diff --git a/lib/Support/MemoryBuffer.cpp b/lib/Support/MemoryBuffer.cpp
index 80d556cbf5be276e7dee0331b0f35faaafdfe1f1..e2b5b7a585236d25deaa86357585020d4e84bc2a 100644 (file)
--- a/lib/Support/MemoryBuffer.cpp
+++ b/lib/Support/MemoryBuffer.cpp
@@ -48,7 +48,7 @@ MemoryBuffer::~MemoryBuffer() { }
 /// memory, memory that we know is already null terminated.
 void MemoryBuffer::init(const char *BufStart, const char *BufEnd,
                         bool RequiresNullTerminator) {
-  assert((BufEnd[0] == 0 || !RequiresNullTerminator) &&
+  assert((!RequiresNullTerminator || BufEnd[0] == 0) &&
          "Buffer is not null terminated!");
   BufferStart = BufStart;
   BufferEnd = BufEnd;
@@ -86,14 +86,20 @@ public:
      // The name is stored after the class itself.
     return reinterpret_cast<const char*>(this + 1);
   }
+  
+  virtual BufferKind getBufferKind() const {
+    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(StringRef InputData,
-                                         StringRef BufferName) {
-  return GetNamedBuffer<MemoryBufferMem>(InputData, BufferName, true);
+                                         StringRef BufferName,
+                                         bool RequiresNullTerminator) {
+  return GetNamedBuffer<MemoryBufferMem>(InputData, BufferName,
+                                         RequiresNullTerminator);
 }
 
 /// getMemBufferCopy - Open the specified memory range as a MemoryBuffer,
@@ -189,20 +195,27 @@ public:
     sys::Path::UnMapFilePages(reinterpret_cast<const char*>(RealStart),
                               RealSize);
   }
+  
+  virtual BufferKind getBufferKind() const {
+    return MemoryBuffer_MMap;
+  }
 };
 }
 
 error_code MemoryBuffer::getFile(StringRef Filename,
                                  OwningPtr<MemoryBuffer> &result,
-                                 int64_t FileSize) {
+                                 int64_t FileSize,
+                                 bool RequiresNullTerminator) {
   // Ensure the path is null terminated.
   SmallString<256> PathBuf(Filename.begin(), Filename.end());
-  return MemoryBuffer::getFile(PathBuf.c_str(), result, FileSize);
+  return MemoryBuffer::getFile(PathBuf.c_str(), result, FileSize,
+                               RequiresNullTerminator);
 }
 
 error_code MemoryBuffer::getFile(const char *Filename,
                                  OwningPtr<MemoryBuffer> &result,
-                                 int64_t FileSize) {
+                                 int64_t FileSize,
+                                 bool RequiresNullTerminator) {
   int OpenFlags = O_RDONLY;
 #ifdef O_BINARY
   OpenFlags |= O_BINARY;  // Open input file in binary mode on win32.
@@ -211,12 +224,14 @@ error_code MemoryBuffer::getFile(const char *Filename,
   if (FD == -1) {
     return error_code(errno, posix_category());
   }
-  error_code ret = getOpenFile(FD, Filename, result, FileSize);
+  error_code ret = getOpenFile(FD, Filename, result, FileSize, FileSize,
+                               0, RequiresNullTerminator);
   close(FD);
   return ret;
 }
 
-static bool shouldUseMmap(size_t FileSize,
+static bool shouldUseMmap(int FD,
+                          size_t FileSize,
                           size_t MapSize,
                           off_t Offset,
                           bool RequiresNullTerminator,
@@ -229,6 +244,20 @@ static bool shouldUseMmap(size_t FileSize,
   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.
+  // FIXME: this chunk of code is duplicated, but it avoids a fstat when
+  // RequiresNullTerminator = false and MapSize != -1.
+  if (FileSize == size_t(-1)) {
+    struct stat FileInfo;
+    // TODO: This should use fstat64 when available.
+    if (fstat(FD, &FileInfo) == -1) {
+      return error_code(errno, posix_category());
+    }
+    FileSize = FileInfo.st_size;
+  }
+
   // 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;
@@ -251,22 +280,22 @@ error_code MemoryBuffer::getOpenFile(int FD, const char *Filename,
                                      bool RequiresNullTerminator) {
   static int PageSize = sys::Process::GetPageSize();
 
-  // 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 == size_t(-1)) {
-    struct stat FileInfo;
-    // TODO: This should use fstat64 when available.
-    if (fstat(FD, &FileInfo) == -1) {
-      return error_code(errno, posix_category());
-    }
-    FileSize = FileInfo.st_size;
-  }
-
   // Default is to map the full file.
-  if (MapSize == size_t(-1))
+  if (MapSize == size_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 == size_t(-1)) {
+      struct stat FileInfo;
+      // TODO: This should use fstat64 when available.
+      if (fstat(FD, &FileInfo) == -1) {
+        return error_code(errno, posix_category());
+      }
+      FileSize = FileInfo.st_size;
+    }
     MapSize = FileSize;
+  }
 
-  if (shouldUseMmap(FileSize, MapSize, Offset, RequiresNullTerminator,
+  if (shouldUseMmap(FD, FileSize, MapSize, Offset, RequiresNullTerminator,
                     PageSize)) {
     off_t RealMapOffset = Offset & ~(PageSize - 1);
     off_t Delta = Offset - RealMapOffset;