1// -*- mode: C++ -*-
2
3// Copyright (c) 2010 Google Inc.
4// All rights reserved.
5//
6// Redistribution and use in source and binary forms, with or without
7// modification, are permitted provided that the following conditions are
8// met:
9//
10//     * Redistributions of source code must retain the above copyright
11// notice, this list of conditions and the following disclaimer.
12//     * Redistributions in binary form must reproduce the above
13// copyright notice, this list of conditions and the following disclaimer
14// in the documentation and/or other materials provided with the
15// distribution.
16//     * Neither the name of Google Inc. nor the names of its
17// contributors may be used to endorse or promote products derived from
18// this software without specific prior written permission.
19//
20// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31
32// stackwalker_arm.h: arm-specific stackwalker.
33//
34// Provides stack frames given arm register context and a memory region
35// corresponding to an arm stack.
36//
37// Author: Mark Mentovai, Ted Mielczarek
38
39
40#ifndef PROCESSOR_STACKWALKER_ARM_H__
41#define PROCESSOR_STACKWALKER_ARM_H__
42
43#include "google_breakpad/common/breakpad_types.h"
44#include "google_breakpad/common/minidump_format.h"
45#include "google_breakpad/processor/stackwalker.h"
46
47namespace google_breakpad {
48
49class CodeModules;
50
51class StackwalkerARM : public Stackwalker {
52 public:
53  // context is an arm context object that gives access to arm-specific
54  // register state corresponding to the innermost called frame to be
55  // included in the stack.  The other arguments are passed directly through
56  // to the base Stackwalker constructor.
57  StackwalkerARM(const SystemInfo* system_info,
58                 const MDRawContextARM* context,
59                 int fp_register,
60                 MemoryRegion* memory,
61                 const CodeModules* modules,
62                 StackFrameSymbolizer* frame_symbolizer);
63
64  // Change the context validity mask of the frame returned by
65  // GetContextFrame to VALID. This is only for use by unit tests; the
66  // default behavior is correct for all application code.
67  void SetContextFrameValidity(int valid) { context_frame_validity_ = valid; }
68
69 private:
70  // Implementation of Stackwalker, using arm context and stack conventions.
71  virtual StackFrame* GetContextFrame();
72  virtual StackFrame* GetCallerFrame(const CallStack* stack,
73                                     bool stack_scan_allowed);
74
75  // Use cfi_frame_info (derived from STACK CFI records) to construct
76  // the frame that called frames.back(). The caller takes ownership
77  // of the returned frame. Return NULL on failure.
78  StackFrameARM* GetCallerByCFIFrameInfo(const vector<StackFrame*> &frames,
79                                         CFIFrameInfo* cfi_frame_info);
80
81  // Use the frame pointer. The caller takes ownership of the returned frame.
82  // Return NULL on failure.
83  StackFrameARM* GetCallerByFramePointer(const vector<StackFrame*> &frames);
84
85  // Scan the stack for plausible return addresses. The caller takes ownership
86  // of the returned frame. Return NULL on failure.
87  StackFrameARM* GetCallerByStackScan(const vector<StackFrame*> &frames);
88
89  // Stores the CPU context corresponding to the youngest stack frame, to
90  // be returned by GetContextFrame.
91  const MDRawContextARM* context_;
92
93  // The register to use a as frame pointer. The value is -1 if frame pointer
94  // cannot be used.
95  int fp_register_;
96
97  // Validity mask for youngest stack frame. This is always
98  // CONTEXT_VALID_ALL in real use; it is only changeable for the sake of
99  // unit tests.
100  int context_frame_validity_;
101};
102
103
104}  // namespace google_breakpad
105
106
107#endif  // PROCESSOR_STACKWALKER_ARM_H__
108