1// -*- mode: C++ -*-
2
3// Copyright (c) 2010 Google Inc.
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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