1 files changed, 104 insertions, 0 deletions
diff --git a/libdexfile/dex/dex_file_exception_helpers.cc b/libdexfile/dex/dex_file_exception_helpers.cc
new file mode 100644
index 0000000000..8e597fd3dd
--- /dev/null
+++ b/libdexfile/dex/dex_file_exception_helpers.cc
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * 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 "dex_file_exception_helpers.h"
+
+#include "code_item_accessors-inl.h"
+
+namespace art {
+
+CatchHandlerIterator::CatchHandlerIterator(const CodeItemDataAccessor& accessor, uint32_t address) {
+  handler_.address_ = -1;
+  int32_t offset = -1;
+
+  // Short-circuit the overwhelmingly common cases.
+  switch (accessor.TriesSize()) {
+    case 0:
+      break;
+    case 1: {
+      const DexFile::TryItem* tries = accessor.TryItems().begin();
+      uint32_t start = tries->start_addr_;
+      if (address >= start) {
+        uint32_t end = start + tries->insn_count_;
+        if (address < end) {
+          offset = tries->handler_off_;
+        }
+      }
+      break;
+    }
+    default: {
+      const DexFile::TryItem* try_item = accessor.FindTryItem(address);
+      offset = try_item != nullptr ? try_item->handler_off_ : -1;
+      break;
+    }
+  }
+  Init(accessor, offset);
+}
+
+CatchHandlerIterator::CatchHandlerIterator(const CodeItemDataAccessor& accessor,
+                                           const DexFile::TryItem& try_item) {
+  handler_.address_ = -1;
+  Init(accessor, try_item.handler_off_);
+}
+
+void CatchHandlerIterator::Init(const CodeItemDataAccessor& accessor, int32_t offset) {
+  if (offset >= 0) {
+    Init(accessor.GetCatchHandlerData(offset));
+  } else {
+    // Not found, initialize as empty
+    current_data_ = nullptr;
+    remaining_count_ = -1;
+    catch_all_ = false;
+    DCHECK(!HasNext());
+  }
+}
+
+void CatchHandlerIterator::Init(const uint8_t* handler_data) {
+  current_data_ = handler_data;
+  remaining_count_ = DecodeSignedLeb128(&current_data_);
+
+  // If remaining_count_ is non-positive, then it is the negative of
+  // the number of catch types, and the catches are followed by a
+  // catch-all handler.
+  if (remaining_count_ <= 0) {
+    catch_all_ = true;
+    remaining_count_ = -remaining_count_;
+  } else {
+    catch_all_ = false;
+  }
+  Next();
+}
+
+void CatchHandlerIterator::Next() {
+  if (remaining_count_ > 0) {
+    handler_.type_idx_ = dex::TypeIndex(DecodeUnsignedLeb128(&current_data_));
+    handler_.address_  = DecodeUnsignedLeb128(&current_data_);
+    remaining_count_--;
+    return;
+  }
+
+  if (catch_all_) {
+    handler_.type_idx_ = dex::TypeIndex(DexFile::kDexNoIndex16);
+    handler_.address_  = DecodeUnsignedLeb128(&current_data_);
+    catch_all_ = false;
+    return;
+  }
+
+  // no more handler
+  remaining_count_ = -1;
+}
+
+}  // namespace art