1 files changed, 103 insertions, 0 deletions
diff --git a/llvm/lib/Support/BinaryStreamWriter.cpp b/llvm/lib/Support/BinaryStreamWriter.cpp
new file mode 100644
index 000000000000..986e18da281d
--- /dev/null
+++ b/llvm/lib/Support/BinaryStreamWriter.cpp
@@ -0,0 +1,103 @@
+//===- BinaryStreamWriter.cpp - Writes objects to a BinaryStream ----------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/BinaryStreamWriter.h"
+
+#include "llvm/Support/BinaryStreamError.h"
+#include "llvm/Support/BinaryStreamReader.h"
+#include "llvm/Support/BinaryStreamRef.h"
+#include "llvm/Support/LEB128.h"
+
+using namespace llvm;
+
+BinaryStreamWriter::BinaryStreamWriter(WritableBinaryStreamRef Ref)
+    : Stream(Ref) {}
+
+BinaryStreamWriter::BinaryStreamWriter(WritableBinaryStream &Stream)
+    : Stream(Stream) {}
+
+BinaryStreamWriter::BinaryStreamWriter(MutableArrayRef<uint8_t> Data,
+                                       llvm::support::endianness Endian)
+    : Stream(Data, Endian) {}
+
+Error BinaryStreamWriter::writeBytes(ArrayRef<uint8_t> Buffer) {
+  if (auto EC = Stream.writeBytes(Offset, Buffer))
+    return EC;
+  Offset += Buffer.size();
+  return Error::success();
+}
+
+Error BinaryStreamWriter::writeULEB128(uint64_t Value) {
+  uint8_t EncodedBytes[10] = {0};
+  unsigned Size = encodeULEB128(Value, &EncodedBytes[0]);
+  return writeBytes({EncodedBytes, Size});
+}
+
+Error BinaryStreamWriter::writeSLEB128(int64_t Value) {
+  uint8_t EncodedBytes[10] = {0};
+  unsigned Size = encodeSLEB128(Value, &EncodedBytes[0]);
+  return writeBytes({EncodedBytes, Size});
+}
+
+Error BinaryStreamWriter::writeCString(StringRef Str) {
+  if (auto EC = writeFixedString(Str))
+    return EC;
+  if (auto EC = writeObject('\0'))
+    return EC;
+
+  return Error::success();
+}
+
+Error BinaryStreamWriter::writeFixedString(StringRef Str) {
+
+  return writeBytes(arrayRefFromStringRef(Str));
+}
+
+Error BinaryStreamWriter::writeStreamRef(BinaryStreamRef Ref) {
+  return writeStreamRef(Ref, Ref.getLength());
+}
+
+Error BinaryStreamWriter::writeStreamRef(BinaryStreamRef Ref, uint32_t Length) {
+  BinaryStreamReader SrcReader(Ref.slice(0, Length));
+  // This is a bit tricky.  If we just call readBytes, we are requiring that it
+  // return us the entire stream as a contiguous buffer.  There is no guarantee
+  // this can be satisfied by returning a reference straight from the buffer, as
+  // an implementation may not store all data in a single contiguous buffer.  So
+  // we iterate over each contiguous chunk, writing each one in succession.
+  while (SrcReader.bytesRemaining() > 0) {
+    ArrayRef<uint8_t> Chunk;
+    if (auto EC = SrcReader.readLongestContiguousChunk(Chunk))
+      return EC;
+    if (auto EC = writeBytes(Chunk))
+      return EC;
+  }
+  return Error::success();
+}
+
+std::pair<BinaryStreamWriter, BinaryStreamWriter>
+BinaryStreamWriter::split(uint32_t Off) const {
+  assert(getLength() >= Off);
+
+  WritableBinaryStreamRef First = Stream.drop_front(Offset);
+
+  WritableBinaryStreamRef Second = First.drop_front(Off);
+  First = First.keep_front(Off);
+  BinaryStreamWriter W1{First};
+  BinaryStreamWriter W2{Second};
+  return std::make_pair(W1, W2);
+}
+
+Error BinaryStreamWriter::padToAlignment(uint32_t Align) {
+  uint32_t NewOffset = alignTo(Offset, Align);
+  if (NewOffset > getLength())
+    return make_error<BinaryStreamError>(stream_error_code::stream_too_short);
+  while (Offset < NewOffset)
+    if (auto EC = writeInteger('\0'))
+      return EC;
+  return Error::success();
+}