[Support] Make FileOutputBuffer work on Windows.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169167 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/FileOutputBuffer.h

@@ -14,14 +14,14 @@
 #ifndef LLVM_SUPPORT_FILEOUTPUTBUFFER_H
 #define LLVM_SUPPORT_FILEOUTPUTBUFFER_H
 
+#include "llvm/ADT/OwningPtr.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/FileSystem.h"
 
 namespace llvm {
-
 class error_code;
-template<class T> class OwningPtr;
 
 /// FileOutputBuffer - This interface provides simple way to create an in-memory
 /// buffer which will be written to a file. During the lifetime of these
@@ -42,22 +42,21 @@ public:
   /// to the file at the specified path.
   static error_code create(StringRef FilePath, size_t Size,
                            OwningPtr<FileOutputBuffer> &Result,
-                           unsigned Flags=0);
-  
+                           unsigned Flags = 0);
 
   /// Returns a pointer to the start of the buffer.
-  uint8_t *getBufferStart() const {
-    return BufferStart;
+  uint8_t *getBufferStart() {
+    return (uint8_t*)Region->data();
   }
 
   /// Returns a pointer to the end of the buffer.
-  uint8_t *getBufferEnd() const {
-    return BufferEnd;
+  uint8_t *getBufferEnd() {
+    return (uint8_t*)Region->data() + Region->size();
   }
 
   /// Returns size of the buffer.
   size_t getBufferSize() const {
-    return BufferEnd - BufferStart;
+    return Region->size();
   }
 
   /// Returns path where file will show up if buffer is committed.
@@ -77,22 +76,17 @@ public:
   /// deallocates the buffer and the target file is never written.
   ~FileOutputBuffer();
 
-  
 private:
   FileOutputBuffer(const FileOutputBuffer &) LLVM_DELETED_FUNCTION;
   FileOutputBuffer &operator=(const FileOutputBuffer &) LLVM_DELETED_FUNCTION;
-protected:
-  FileOutputBuffer(uint8_t *Start, uint8_t *End,
+
+  FileOutputBuffer(llvm::sys::fs::mapped_file_region *R,
                    StringRef Path, StringRef TempPath);
 
-  uint8_t            *BufferStart;
-  uint8_t            *BufferEnd;
+  OwningPtr<llvm::sys::fs::mapped_file_region> Region;
   SmallString<128>    FinalPath;
   SmallString<128>    TempPath;
 };
-
-
-
 } // end namespace llvm
 
 #endif

lib/Support/FileOutputBuffer.cpp

@@ -14,32 +14,24 @@
 #include "llvm/Support/FileOutputBuffer.h"
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/system_error.h"
 
+using llvm::sys::fs::mapped_file_region;
 
 namespace llvm {
-
-
-FileOutputBuffer::FileOutputBuffer(uint8_t *Start, uint8_t *End, 
+FileOutputBuffer::FileOutputBuffer(mapped_file_region * R,
                                    StringRef Path, StringRef TmpPath)
-  : BufferStart(Start), BufferEnd(End) {
-  FinalPath.assign(Path);
-  TempPath.assign(TmpPath);
+  : Region(R)
+  , FinalPath(Path)
+  , TempPath(TmpPath) {
 }
 
-
 FileOutputBuffer::~FileOutputBuffer() {
-  // If not already commited, delete buffer and remove temp file.
-  if ( BufferStart != NULL ) {
-    sys::fs::unmap_file_pages((void*)BufferStart, getBufferSize());
   bool Existed;
   sys::fs::remove(Twine(TempPath), Existed);
-  }
 }
 
- 
 error_code FileOutputBuffer::create(StringRef FilePath,
                                     size_t Size,
                                     OwningPtr<FileOutputBuffer> &Result,
@@ -78,15 +70,8 @@ error_code FileOutputBuffer::create(StringRef FilePath,
   if (EC)
     return EC;
 
-  // The unique_file() interface leaks lower layers and returns a file 
-  // descriptor.  There is no way to directly close it, so use this hack
-  // to hand it off to raw_fd_ostream to close for us.
-  {
-    raw_fd_ostream Dummy(FD, /*shouldClose=*/true);
-  }
-  
-  // Resize file to requested initial size
-  EC = sys::fs::resize_file(Twine(TempFilePath), Size);
+  OwningPtr<mapped_file_region> MappedFile(
+    new mapped_file_region(FD, mapped_file_region::readwrite, Size, 0, EC));
   if (EC)
     return EC;
 
@@ -110,30 +95,20 @@ error_code FileOutputBuffer::create(StringRef FilePath,
       return EC;
   }
 
-  // Memory map new file.
-  void *Base;
-  EC = sys::fs::map_file_pages(Twine(TempFilePath), 0, Size, true, Base);
-  if (EC)
-    return EC;
-  
-  // Create FileOutputBuffer object to own mapped range.
-  uint8_t *Start = reinterpret_cast<uint8_t*>(Base);
-  Result.reset(new FileOutputBuffer(Start, Start+Size, FilePath, TempFilePath));
+  Result.reset(new FileOutputBuffer(MappedFile.get(), FilePath, TempFilePath));
+  if (Result)
+    MappedFile.take();
 
   return error_code::success();
 }
 
-
 error_code FileOutputBuffer::commit(int64_t NewSmallerSize) {
   // Unmap buffer, letting OS flush dirty pages to file on disk.
-  void *Start = reinterpret_cast<void*>(BufferStart);
-  error_code EC = sys::fs::unmap_file_pages(Start, getBufferSize());
-  if (EC)
-    return EC;
+  Region.reset(0);
 
   // If requested, resize file as part of commit.
   if ( NewSmallerSize != -1 ) {
-    EC = sys::fs::resize_file(Twine(TempPath), NewSmallerSize);
+    error_code EC = sys::fs::resize_file(Twine(TempPath), NewSmallerSize);
     if (EC)
       return EC;
   }
@@ -141,7 +116,4 @@ error_code FileOutputBuffer::commit(int64_t NewSmallerSize) {
   // Rename file to final name.
   return sys::fs::rename(Twine(TempPath), Twine(FinalPath));
 }
-
-
 } // namespace
-

unittests/Support/FileOutputBufferTest.cpp

@@ -7,9 +7,10 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Support/FileOutputBuffer.h"
+
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/FileOutputBuffer.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/PathV2.h"
 #include "llvm/Support/raw_ostream.h"
@@ -27,13 +28,6 @@ using namespace llvm::sys;
   } else {}
 
 namespace {
-
-
-// NOTE: Temporarily run this test on unix only.  Once the file mapping
-// routines are ported to Windows, this conditional can be removed.
-#if LLVM_ON_UNIX
-
-
 TEST(FileOutputBuffer, Test) {
   // Create unique temporary directory for these tests
   SmallString<128> TestDirectory;
@@ -84,7 +78,6 @@ TEST(FileOutputBuffer, Test) {
   ASSERT_NO_ERROR(fs::exists(Twine(File2), Exists));
   EXPECT_FALSE(Exists);
 
-
   // TEST 3: Verify sizing down case.
   SmallString<128> File3(TestDirectory);
 	File3.append("/file3");
@@ -108,7 +101,6 @@ TEST(FileOutputBuffer, Test) {
   ASSERT_NO_ERROR(fs::file_size(Twine(File3), File3Size));
   ASSERT_EQ(File3Size, 5000ULL);
 
-
   // TEST 4: Verify file can be made executable.
   SmallString<128> File4(TestDirectory);
 	File4.append("/file4");
@@ -131,7 +123,4 @@ TEST(FileOutputBuffer, Test) {
   uint32_t RemovedCount;
   ASSERT_NO_ERROR(fs::remove_all(TestDirectory.str(), RemovedCount));
 }
-
-#endif // LLVM_ON_UNIX
-
 } // anonymous namespace