Refactor dump_memory function.

- Add dumping memory around registers for x86/x86_64.
- Add unit tests for new dump_memory function.
- Cleanup all of the machine.cpp files.
- Increase the high address check for 32 bit, and decrease the high
  address allowed for 64 bit slightly to match mips64.

Bug: 21206576
Change-Id: I6f75141f3282db48b10f7c695a1cf2eb75a08351
diff --git a/debuggerd/test/BacktraceMock.h b/debuggerd/test/BacktraceMock.h
new file mode 100644
index 0000000..05ad12b
--- /dev/null
+++ b/debuggerd/test/BacktraceMock.h
@@ -0,0 +1,97 @@
+/*
+ * 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 _DEBUGGERD_TEST_BACKTRACE_MOCK_H
+#define _DEBUGGERD_TEST_BACKTRACE_MOCK_H
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ucontext.h>
+
+#include <string>
+#include <vector>
+
+#include <backtrace/Backtrace.h>
+#include <backtrace/BacktraceMap.h>
+
+class BacktraceMapMock : public BacktraceMap {
+ public:
+  BacktraceMapMock() : BacktraceMap(0) {}
+  virtual ~BacktraceMapMock() {}
+};
+
+
+class BacktraceMock : public Backtrace {
+ public:
+  BacktraceMock(BacktraceMapMock* map) : Backtrace(0, 0, map) {
+    if (map_ == nullptr) {
+      abort();
+    }
+  }
+  virtual ~BacktraceMock() {}
+
+  virtual bool Unwind(size_t, ucontext_t*) { return false; }
+  virtual bool ReadWord(uintptr_t, word_t*) { return false;}
+
+  virtual std::string GetFunctionNameRaw(uintptr_t, uintptr_t*) { return ""; }
+
+  virtual size_t Read(uintptr_t addr, uint8_t* buffer, size_t bytes) {
+    size_t offset = 0;
+    if (last_read_addr_ > 0) {
+      offset = addr - last_read_addr_;
+    }
+    size_t bytes_available = buffer_.size() - offset;
+
+    if (bytes_partial_read_ > 0) {
+      // Do a partial read.
+      if (bytes > bytes_partial_read_) {
+        bytes = bytes_partial_read_;
+      }
+      bytes_partial_read_ -= bytes;
+    } else if (bytes > bytes_available) {
+      bytes = bytes_available;
+    }
+
+    if (bytes > 0) {
+      memcpy(buffer, buffer_.data() + offset, bytes);
+    }
+
+    last_read_addr_ = addr;
+    return bytes;
+  }
+
+  void SetReadData(uint8_t* buffer, size_t bytes) {
+    buffer_.resize(bytes);
+    memcpy(buffer_.data(), buffer, bytes);
+    bytes_partial_read_ = 0;
+    last_read_addr_ = 0;
+  }
+
+  void SetPartialReadAmount(size_t bytes) {
+    if (bytes > buffer_.size()) {
+      abort();
+    }
+    bytes_partial_read_ = bytes;
+  }
+
+ private:
+  std::vector<uint8_t> buffer_;
+  size_t bytes_partial_read_ = 0;
+  uintptr_t last_read_addr_ = 0;
+};
+
+#endif //  _DEBUGGERD_TEST_BACKTRACE_MOCK_H