Reland Implement .eh_frame writer and disassembler.

test/unittests/eh-frame-iterator-unittest.cc

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/eh-frame.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+// Test enabled only on supported architectures.
+#if defined(V8_TARGET_ARCH_X64) || defined(V8_TARGET_ARCH_ARM) || \
+    defined(V8_TARGET_ARCH_ARM64)
+
+using namespace v8::internal;
+
+namespace {
+
+class EhFrameIteratorTest : public testing::Test {};
+
+}  // namespace
+
+TEST_F(EhFrameIteratorTest, Values) {
+  // Assuming little endian.
+  static const byte kEncoded[] = {0xde, 0xc0, 0xad, 0xde, 0xef, 0xbe, 0xff};
+  EhFrameIterator iterator(&kEncoded[0], &kEncoded[0] + sizeof(kEncoded));
+  EXPECT_EQ(0xdeadc0de, iterator.GetNextUInt32());
+  EXPECT_EQ(0xbeef, iterator.GetNextUInt16());
+  EXPECT_EQ(0xff, iterator.GetNextByte());
+  EXPECT_TRUE(iterator.Done());
+}
+
+TEST_F(EhFrameIteratorTest, Skip) {
+  static const byte kEncoded[] = {0xde, 0xad, 0xc0, 0xde};
+  EhFrameIterator iterator(&kEncoded[0], &kEncoded[0] + sizeof(kEncoded));
+  iterator.Skip(2);
+  EXPECT_EQ(2, iterator.GetCurrentOffset());
+  EXPECT_EQ(0xc0, iterator.GetNextByte());
+  iterator.Skip(1);
+  EXPECT_TRUE(iterator.Done());
+}
+
+TEST_F(EhFrameIteratorTest, ULEB128Decoding) {
+  static const byte kEncoded[] = {0xe5, 0x8e, 0x26};
+  EhFrameIterator iterator(&kEncoded[0], &kEncoded[0] + sizeof(kEncoded));
+  EXPECT_EQ(624485, iterator.GetNextULeb128());
+  EXPECT_TRUE(iterator.Done());
+}
+
+TEST_F(EhFrameIteratorTest, SLEB128DecodingPositive) {
+  static const byte kEncoded[] = {0xe5, 0x8e, 0x26};
+  EhFrameIterator iterator(&kEncoded[0], &kEncoded[0] + sizeof(kEncoded));
+  EXPECT_EQ(624485, iterator.GetNextSLeb128());
+  EXPECT_TRUE(iterator.Done());
+}
+
+TEST_F(EhFrameIteratorTest, SLEB128DecodingNegative) {
+  static const byte kEncoded[] = {0x9b, 0xf1, 0x59};
+  EhFrameIterator iterator(&kEncoded[0], &kEncoded[0] + sizeof(kEncoded));
+  EXPECT_EQ(-624485, iterator.GetNextSLeb128());
+  EXPECT_TRUE(iterator.Done());
+}
+
+#endif