+// The raw_svector_ostream implementation uses the SmallVector itself as the
+// buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
+// always pointing past the end of the vector, but within the vector
+// capacity. This allows raw_ostream to write directly into the correct place,
+// and we only need to set the vector size when the data is flushed.
+
+raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
+ // Set up the initial external buffer. We make sure that the buffer has at
+ // least 128 bytes free; raw_ostream itself only requires 64, but we want to
+ // make sure that we don't grow the buffer unnecessarily on destruction (when
+ // the data is flushed). See the FIXME below.
+ OS.reserve(OS.size() + 128);
+ SetBuffer(OS.end(), OS.capacity() - OS.size());
+}
+
+raw_svector_ostream::~raw_svector_ostream() {
+ // FIXME: Prevent resizing during this flush().
+ flush();
+}
+
+/// resync - This is called when the SmallVector we're appending to is changed
+/// outside of the raw_svector_ostream's control. It is only safe to do this
+/// if the raw_svector_ostream has previously been flushed.
+void raw_svector_ostream::resync() {
+ assert(GetNumBytesInBuffer() == 0 && "Didn't flush before mutating vector");
+
+ if (OS.capacity() - OS.size() < 64)
+ OS.reserve(OS.capacity() * 2);
+ SetBuffer(OS.end(), OS.capacity() - OS.size());
+}
+
+void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
+ // If we're writing bytes from the end of the buffer into the smallvector, we
+ // don't need to copy the bytes, just commit the bytes because they are
+ // already in the right place.
+ if (Ptr == OS.end()) {
+ assert(OS.size() + Size <= OS.capacity() && "Invalid write_impl() call!");
+ OS.set_size(OS.size() + Size);
+ } else {
+ assert(GetNumBytesInBuffer() == 0 &&
+ "Should be writing from buffer if some bytes in it");
+ // Otherwise, do copy the bytes.
+ OS.append(Ptr, Ptr+Size);
+ }
+
+ // Grow the vector if necessary.
+ if (OS.capacity() - OS.size() < 64)
+ OS.reserve(OS.capacity() * 2);
+
+ // Update the buffer position.
+ SetBuffer(OS.end(), OS.capacity() - OS.size());
+}
+
+uint64_t raw_svector_ostream::current_pos() const {
+ return OS.size();
+}
+
+StringRef raw_svector_ostream::str() {
+ flush();
+ return StringRef(OS.begin(), OS.size());
+}
+
+//===----------------------------------------------------------------------===//
+// raw_null_ostream
+//===----------------------------------------------------------------------===//
+
+raw_null_ostream::~raw_null_ostream() {
+#ifndef NDEBUG
+ // ~raw_ostream asserts that the buffer is empty. This isn't necessary
+ // with raw_null_ostream, but it's better to have raw_null_ostream follow
+ // the rules than to change the rules just for raw_null_ostream.
+ flush();
+#endif
+}
+
+void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
+}
+
+uint64_t raw_null_ostream::current_pos() const {
+ return 0;