1 files changed, 67 insertions, 0 deletions
diff --git a/third_party/wasm2c/src/lexer-source.cc b/third_party/wasm2c/src/lexer-source.cc
new file mode 100644
index 0000000000..eff56e2571
--- /dev/null
+++ b/third_party/wasm2c/src/lexer-source.cc
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2017 WebAssembly Community Group participants
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "wabt/lexer-source.h"
+
+#include <algorithm>
+
+namespace wabt {
+
+LexerSource::LexerSource(const void* data, Offset size)
+    : data_(data), size_(size), read_offset_(0) {}
+
+std::unique_ptr<LexerSource> LexerSource::Clone() {
+  LexerSource* result = new LexerSource(data_, size_);
+  result->read_offset_ = read_offset_;
+  return std::unique_ptr<LexerSource>(result);
+}
+
+Result LexerSource::Tell(Offset* out_offset) {
+  *out_offset = read_offset_;
+  return Result::Ok;
+}
+
+size_t LexerSource::Fill(void* dest, Offset size) {
+  Offset read_size = std::min(size, size_ - read_offset_);
+  if (read_size > 0) {
+    const void* src = static_cast<const char*>(data_) + read_offset_;
+    memcpy(dest, src, read_size);
+    read_offset_ += read_size;
+  }
+  return read_size;
+}
+
+Result LexerSource::Seek(Offset offset) {
+  if (offset < size_) {
+    read_offset_ = offset;
+    return Result::Ok;
+  }
+  return Result::Error;
+}
+
+Result LexerSource::ReadRange(OffsetRange range, std::vector<char>* out_data) {
+  OffsetRange clamped = range;
+  clamped.start = std::min(clamped.start, size_);
+  clamped.end = std::min(clamped.end, size_);
+  if (clamped.size()) {
+    out_data->resize(clamped.size());
+    const void* src = static_cast<const char*>(data_) + clamped.start;
+    memcpy(out_data->data(), src, clamped.size());
+  }
+  return Result::Ok;
+}
+
+}  // namespace wabt