[ARM] Allow TargetParser to accurately target architectures

[oota-llvm.git] / include / llvm / Support / StreamingMemoryObject.h

diff --git a/include/llvm/Support/StreamingMemoryObject.h b/include/llvm/Support/StreamingMemoryObject.h
index 9d1d607005f21c8702df0912bee2c8148c2bc6c4..a5980c235946151aa847c2d5ea9f67a120166b98 100644 (file)
--- a/include/llvm/Support/StreamingMemoryObject.h
+++ b/include/llvm/Support/StreamingMemoryObject.h
@@ -24,7 +24,7 @@ namespace llvm {
 /// setKnownObjectSize methods which are not applicable to non-streamed objects.
 class StreamingMemoryObject : public MemoryObject {
 public:
-  StreamingMemoryObject(DataStreamer *streamer);
+  StreamingMemoryObject(std::unique_ptr<DataStreamer> Streamer);
   uint64_t getExtent() const override;
   uint64_t readBytes(uint8_t *Buf, uint64_t Size,
                      uint64_t Address) const override;
@@ -50,8 +50,10 @@ public:
   /// starts (although it can be called anytime).
   void setKnownObjectSize(size_t size);
 
+  /// The number of bytes read at a time from the data streamer.
+  static const uint32_t kChunkSize = 4096 * 4;
+
 private:
-  const static uint32_t kChunkSize = 4096 * 4;
   mutable std::vector<unsigned char> Bytes;
   std::unique_ptr<DataStreamer> Streamer;
   mutable size_t BytesRead;   // Bytes read from stream
@@ -59,26 +61,27 @@ private:
   mutable size_t ObjectSize; // 0 if unknown, set if wrapper seen or EOF reached
   mutable bool EOFReached;
 
-  // Fetch enough bytes such that Pos can be read or EOF is reached
-  // (i.e. BytesRead > Pos). Return true if Pos can be read.
-  // Unlike most of the functions in BitcodeReader, returns true on success.
-  // Most of the requests will be small, but we fetch at kChunkSize bytes
-  // at a time to avoid making too many potentially expensive GetBytes calls
+  // Fetch enough bytes such that Pos can be read (i.e. BytesRead >
+  // Pos). Returns true if Pos can be read.  Unlike most of the
+  // functions in BitcodeReader, returns true on success.  Most of the
+  // requests will be small, but we fetch at kChunkSize bytes at a
+  // time to avoid making too many potentially expensive GetBytes
+  // calls.
   bool fetchToPos(size_t Pos) const {
-    if (EOFReached)
-      return Pos < ObjectSize;
     while (Pos >= BytesRead) {
+      if (EOFReached)
+        return false;
       Bytes.resize(BytesRead + BytesSkipped + kChunkSize);
       size_t bytes = Streamer->GetBytes(&Bytes[BytesRead + BytesSkipped],
                                         kChunkSize);
       BytesRead += bytes;
-      if (bytes != kChunkSize) { // reached EOF/ran out of bytes
-        ObjectSize = BytesRead;
+      if (bytes == 0) { // reached EOF/ran out of bytes
+        if (ObjectSize == 0)
+          ObjectSize = BytesRead;
         EOFReached = true;
-        break;
       }
     }
-    return Pos < BytesRead;
+    return !ObjectSize || Pos < ObjectSize;
   }
 
   StreamingMemoryObject(const StreamingMemoryObject&) = delete;