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exception.h
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24 
25 #ifndef PXR_BASE_TF_EXCEPTION_H
26 #define PXR_BASE_TF_EXCEPTION_H
27 
28 /// \file tf/exception.h
29 /// \ingroup group_tf_Diagnostic
30 
31 #include "pxr/pxr.h"
32 #include "pxr/base/tf/api.h"
35 
36 #include <cstdint>
37 #include <exception>
38 #include <string>
39 #include <vector>
40 
42 
43 /// This structure is used to indicate that some number of caller frames should
44 /// be skipped when capturing exception stack traces at the throw point.
46 {
47  explicit TfSkipCallerFrames(int n=0) : numToSkip(n) {}
48  int numToSkip;
49 };
50 
51 /// The base class for exceptions supported by the Tf exceptions facilities.
52 /// Typical usage is to publically derive your own exception class from this
53 /// one, and throw using the TF_THROW() macro.
54 ///
55 /// Deriving this base class and throwing via TF_THROW() will record the throw
56 /// point's call context (see GetThrowContext()) and will also capture a portion
57 /// of the throwing thread's call stack (see GetThrowStack()).
58 ///
59 /// Additionally, the Tf library registers an exception translator with
60 /// hboost.python to raise a Python exeption wrapping the thrown exception
61 /// object. Similarly utilties that call Python via Tf will re-throw the
62 /// embedded C++ exception if the Python exception unwinds back into C++.
63 class TfBaseException : public std::exception
64 {
65 public:
66  TF_API
67  virtual ~TfBaseException();
68 
69  /// Construct with \p message, reported by this class's what()
70  /// implementation.
71  TF_API
72  explicit TfBaseException(std::string const &message);
73 
74  /// Return the call context from the throw point associated with this
75  /// exception. Note that this context may be invalid if this exception was
76  /// not thrown with TF_THROW().
77  TfCallContext const &GetThrowContext() const {
78  return _callContext;
79  }
80 
81  /// Return the stack frame pointers from the throw point. See
82  /// ArchPrintStackFrames() to turn these into human-readable strings.
83  std::vector<uintptr_t> const &GetThrowStack() const {
84  return _throwStack;
85  }
86 
87  /// Move the stack frame pointers from the throw point to \p out. See
88  /// GetThrowStack() for more details.
89  void MoveThrowStackTo(std::vector<uintptr_t> &out) {
90  out = std::move(_throwStack);
91  _throwStack.clear();
92  }
93 
94  /// Override std::exception::what() to return the message passed during
95  /// construction.
96  TF_API
97  virtual const char *what() const noexcept override;
98 
99  // Friend throw support.
100  template <class Derived, class ... Args>
101  friend void
102  Tf_Throw(TfCallContext const &cc,
103  TfSkipCallerFrames skipFrames,
104  Args && ... args);
105 
106 private:
107  TF_API
108  static void _ThrowImpl(TfCallContext const &cc,
109  TfBaseException &exc,
110  TfFunctionRef<void ()> thrower,
111  int skipNCallerFrames);
112 
113  TfCallContext _callContext;
114  std::vector<uintptr_t> _throwStack;
115  std::string _message;
116 };
117 
118 // TF_THROW() support function.
119 template <class Exception, class ... Args>
120 void
122  TfSkipCallerFrames skipFrames,
123  Args && ... args) {
124  Exception exc(std::forward<Args>(args)...);
125  auto thrower = [&exc]() { throw std::move(exc); };
126  TfBaseException::_ThrowImpl(cc, exc, thrower, skipFrames.numToSkip);
127 }
128 
129 // TF_THROW() support function.
130 template <class Exception, class ... Args>
131 void Tf_Throw(TfCallContext const &cc, Args && ... args) {
132  Tf_Throw<Exception>(cc, TfSkipCallerFrames(), std::forward<Args>(args)...);
133 }
134 
135 #ifdef doxygen
136 
137 /// Construct an instance of Exception (which must derive TfBaseException) with
138 /// Exception-ctor-args and throw it. Also capture a portion of this thread's
139 /// current call stack and the throw point's source filename & line number to
140 /// embed in the exception. If the exception goes unhandled these will be
141 /// reported in the crash report that Tf's terminate handler generates, or in
142 /// the unhandled exception message in the python interpreter.
143 #define TF_THROW(Exception, Exception-ctor-args...)
144 #define TF_THROW(Exception, TfSkipCallerFrames, Exception-ctor-args...)
145 
146 #else
147 
148 #define TF_THROW(Exception, ...) \
149  Tf_Throw<Exception>(TF_CALL_CONTEXT, __VA_ARGS__)
150 
151 #endif
152 
154 
155 #endif // PXR_BASE_TF_EXCEPTION_H
GLuint GLsizei const GLchar * message
Definition: glcorearb.h:2543
#define TF_API
Definition: api.h:40
*get result *(waiting if necessary)*A common idiom is to fire a bunch of sub tasks at the and then *wait for them to all complete We provide a helper class
Definition: thread.h:623
GLsizei const GLchar *const * string
Definition: glcorearb.h:814
fallback_uintptr uintptr_t
Definition: format.h:295
class OCIOEXPORT Exception
TfCallContext const & GetThrowContext() const
Definition: exception.h:77
GLdouble n
Definition: glcorearb.h:2008
virtual TF_API const char * what() const noexceptoverride
virtual TF_API ~TfBaseException()
std::vector< uintptr_t > const & GetThrowStack() const
Definition: exception.h:83
TF_API TfBaseException(std::string const &message)
PXR_NAMESPACE_CLOSE_SCOPE PXR_NAMESPACE_OPEN_SCOPE
Definition: path.h:1432
#define PXR_NAMESPACE_CLOSE_SCOPE
Definition: pxr.h:91
**If you just want to fire and args
Definition: thread.h:609
friend void Tf_Throw(TfCallContext const &cc, TfSkipCallerFrames skipFrames, Args &&...args)
Definition: exception.h:121
TfSkipCallerFrames(int n=0)
Definition: exception.h:47
void MoveThrowStackTo(std::vector< uintptr_t > &out)
Definition: exception.h:89