1  // -*- mode: C++ -*-
  2  
  3  // Copyright 2010 Google LLC
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 30  
 31  // stackwalker_arm.h: arm-specific stackwalker.
 32  //
 33  // Provides stack frames given arm register context and a memory region
 34  // corresponding to an arm stack.
 35  //
 36  // Author: Mark Mentovai, Ted Mielczarek
 37  
 38  
 39  #ifndef PROCESSOR_STACKWALKER_ARM_H__
 40  #define PROCESSOR_STACKWALKER_ARM_H__
 41  
 42  #include "google_breakpad/common/breakpad_types.h"
 43  #include "google_breakpad/common/minidump_format.h"
 44  #include "google_breakpad/processor/stackwalker.h"
 45  
 46  namespace google_breakpad {
 47  
 48  class CodeModules;
 49  
 50  class StackwalkerARM : public Stackwalker {
 51   public:
 52    // context is an arm context object that gives access to arm-specific
 53    // register state corresponding to the innermost called frame to be
 54    // included in the stack.  The other arguments are passed directly through
 55    // to the base Stackwalker constructor.
 56    StackwalkerARM(const SystemInfo* system_info,
 57                   const MDRawContextARM* context,
 58                   int fp_register,
 59                   MemoryRegion* memory,
 60                   const CodeModules* modules,
 61                   StackFrameSymbolizer* frame_symbolizer);
 62  
 63    // Change the context validity mask of the frame returned by
 64    // GetContextFrame to VALID. This is only for use by unit tests; the
 65    // default behavior is correct for all application code.
 66    void SetContextFrameValidity(int valid) { context_frame_validity_ = valid; }
 67  
 68   private:
 69    // Implementation of Stackwalker, using arm context and stack conventions.
 70    virtual StackFrame* GetContextFrame();
 71    virtual StackFrame* GetCallerFrame(const CallStack* stack,
 72                                       bool stack_scan_allowed);
 73  
 74    // Use cfi_frame_info (derived from STACK CFI records) to construct
 75    // the frame that called frames.back(). The caller takes ownership
 76    // of the returned frame. Return NULL on failure.
 77    StackFrameARM* GetCallerByCFIFrameInfo(const vector<StackFrame*>& frames,
 78                                           CFIFrameInfo* cfi_frame_info);
 79  
 80    // Use the frame pointer. The caller takes ownership of the returned frame.
 81    // Return NULL on failure.
 82    StackFrameARM* GetCallerByFramePointer(const vector<StackFrame*>& frames);
 83  
 84    // Scan the stack for plausible return addresses. The caller takes ownership
 85    // of the returned frame. Return NULL on failure.
 86    StackFrameARM* GetCallerByStackScan(const vector<StackFrame*>& frames);
 87  
 88    // Stores the CPU context corresponding to the youngest stack frame, to
 89    // be returned by GetContextFrame.
 90    const MDRawContextARM* context_;
 91  
 92    // The register to use a as frame pointer. The value is -1 if frame pointer
 93    // cannot be used.
 94    int fp_register_;
 95  
 96    // Validity mask for youngest stack frame. This is always
 97    // CONTEXT_VALID_ALL in real use; it is only changeable for the sake of
 98    // unit tests.
 99    int context_frame_validity_;
100  };
101  
102  
103  }  // namespace google_breakpad
104  
105  
106  #endif  // PROCESSOR_STACKWALKER_ARM_H__