Always use signed leb128 decoder
Relocation packer no longer encodes relocation tables
using unsigned leb128: https://android-review.googlesource.com/147745
Bug: http://b/18051137
Change-Id: I620b7188e5f3dd9d5123431aa1fc7feca76be607
diff --git a/linker/linker_sleb128.h b/linker/linker_sleb128.h
new file mode 100644
index 0000000..a34916f
--- /dev/null
+++ b/linker/linker_sleb128.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#ifndef _LINKER_SLEB128_H
+#define _LINKER_SLEB128_H
+
+#include <stdint.h>
+
+// Helper classes for decoding LEB128, used in packed relocation data.
+// http://en.wikipedia.org/wiki/LEB128
+
+class sleb128_decoder {
+ public:
+ sleb128_decoder(const uint8_t* buffer, size_t count)
+ : current_(buffer), end_(buffer+count) { }
+
+ size_t pop_front() {
+ size_t value = 0;
+ static const size_t size = CHAR_BIT * sizeof(value);
+
+ size_t shift = 0;
+ uint8_t byte;
+
+ do {
+ if (current_ >= end_) {
+ __libc_fatal("sleb128_decoder ran out of bounds");
+ }
+ byte = *current_++;
+ value |= (static_cast<size_t>(byte & 127) << shift);
+ shift += 7;
+ } while (byte & 128);
+
+ if (shift < size && (byte & 64)) {
+ value |= -(static_cast<size_t>(1) << shift);
+ }
+
+ return value;
+ }
+
+ private:
+ const uint8_t* current_;
+ const uint8_t* const end_;
+};
+
+#endif // __LINKER_SLEB128_H