Simplify memory management with std::unique_ptr.

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

diff --git a/lib/Support/Compression.cpp b/lib/Support/Compression.cpp
index 329a402a07045ca5648154f9da43d693f634383b..b54613e92b8b6ba3bf8cb2e2816745b6d909244b 100644 (file)
--- a/lib/Support/Compression.cpp
+++ b/lib/Support/Compression.cpp
@@ -12,11 +12,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/Compression.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Config/config.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/MemoryBuffer.h"
 #if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H
 #include <zlib.h>
 #endif
@@ -47,20 +47,18 @@ static zlib::Status encodeZlibReturnValue(int ReturnValue) {
 
 bool zlib::isAvailable() { return true; }
 zlib::Status zlib::compress(StringRef InputBuffer,
-                            std::unique_ptr<MemoryBuffer> &CompressedBuffer,
+                            SmallVectorImpl<char> &CompressedBuffer,
                             CompressionLevel Level) {
   unsigned long CompressedSize = ::compressBound(InputBuffer.size());
-  std::unique_ptr<char[]> TmpBuffer(new char[CompressedSize]);
+  CompressedBuffer.resize(CompressedSize);
   int CLevel = encodeZlibCompressionLevel(Level);
   Status Res = encodeZlibReturnValue(::compress2(
-      (Bytef *)TmpBuffer.get(), &CompressedSize,
+      (Bytef *)CompressedBuffer.data(), &CompressedSize,
       (const Bytef *)InputBuffer.data(), InputBuffer.size(), CLevel));
-  if (Res == StatusOK) {
-    CompressedBuffer.reset(MemoryBuffer::getMemBufferCopy(
-        StringRef(TmpBuffer.get(), CompressedSize)));
-    // Tell MSan that memory initialized by zlib is valid.
-    __msan_unpoison(CompressedBuffer->getBufferStart(), CompressedSize);
-  }
+  // Tell MemorySanitizer that zlib output buffer is fully initialized.
+  // This avoids a false report when running LLVM with uninstrumented ZLib.
+  __msan_unpoison(CompressedBuffer.data(), CompressedSize);
+  CompressedBuffer.resize(CompressedSize);
   return Res;
 }
 
@@ -71,6 +69,9 @@ zlib::Status zlib::uncompress(StringRef InputBuffer,
   Status Res = encodeZlibReturnValue(::uncompress(
       (Bytef *)UncompressedBuffer.data(), (uLongf *)&UncompressedSize,
       (const Bytef *)InputBuffer.data(), InputBuffer.size()));
+  // Tell MemorySanitizer that zlib output buffer is fully initialized.
+  // This avoids a false report when running LLVM with uninstrumented ZLib.
+  __msan_unpoison(UncompressedBuffer.data(), UncompressedSize);
   UncompressedBuffer.resize(UncompressedSize);
   return Res;
 }
@@ -82,12 +83,12 @@ uint32_t zlib::crc32(StringRef Buffer) {
 #else
 bool zlib::isAvailable() { return false; }
 zlib::Status zlib::compress(StringRef InputBuffer,
-                            std::unique_ptr<MemoryBuffer> &CompressedBuffer,
+                            SmallVectorImpl<char> &CompressedBuffer,
                             CompressionLevel Level) {
   return zlib::StatusUnsupported;
 }
 zlib::Status zlib::uncompress(StringRef InputBuffer,
-                              std::unique_ptr<MemoryBuffer> &UncompressedBuffer,
+                              SmallVectorImpl<char> &UncompressedBuffer,
                               size_t UncompressedSize) {
   return zlib::StatusUnsupported;
 }