exception.h

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//
// Copyright 2021 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
//    names, trademarks, service marks, or product names of the Licensor
//    and its affiliates, except as required to comply with Section 4(c) of
//    the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//

#ifndef PXR_BASE_TF_EXCEPTION_H
#define PXR_BASE_TF_EXCEPTION_H


#include "pxr/pxr.h"
#include "pxr/base/tf/api.h"
#include "pxr/base/tf/callContext.h"
#include "pxr/base/tf/functionRef.h"

#include <cstdint>
#include <exception>
#include <string>
#include <vector>

PXR_NAMESPACE_OPEN_SCOPE

struct TfSkipCallerFrames
{
    explicit TfSkipCallerFrames(int n=0) : numToSkip(n) {}
    int numToSkip;
};

class TfBaseException : public std::exception
{
public:
    TF_API
    virtual ~TfBaseException();

    TF_API
    explicit TfBaseException(std::string const &message);

    TfCallContext const &GetThrowContext() const {
        return _callContext;
    }

    std::vector<uintptr_t> const &GetThrowStack() const {
        return _throwStack;
    }

    void MoveThrowStackTo(std::vector<uintptr_t> &out) {
        out = std::move(_throwStack);
        _throwStack.clear();
    }

    TF_API
    virtual const char *what() const noexcept override;

    // Friend throw support.
    template <class Derived, class ... Args>
    friend void
    Tf_Throw(TfCallContext const &cc,
             TfSkipCallerFrames skipFrames,
             Args && ... args);

private:
    TF_API
    static void _ThrowImpl(TfCallContext const &cc,
                           TfBaseException &exc,
                           TfFunctionRef<void ()> thrower,
                           int skipNCallerFrames);

    TfCallContext _callContext;
    std::vector<uintptr_t> _throwStack;
    std::string _message;
};

// TF_THROW() support function.
template <class Exception, class ... Args>
void
Tf_Throw(TfCallContext const &cc,
         TfSkipCallerFrames skipFrames,
         Args && ... args) {
    Exception exc(std::forward<Args>(args)...);
    auto thrower = [&exc]() { throw std::move(exc); };
    TfBaseException::_ThrowImpl(cc, exc, thrower, skipFrames.numToSkip);
}        

// TF_THROW() support function.
template <class Exception, class ... Args>
void Tf_Throw(TfCallContext const &cc, Args && ... args) {
    Tf_Throw<Exception>(cc, TfSkipCallerFrames(), std::forward<Args>(args)...);
}

#ifdef doxygen

#define TF_THROW(Exception, Exception-ctor-args...)
#define TF_THROW(Exception, TfSkipCallerFrames, Exception-ctor-args...)

#else 

#define TF_THROW(Exception, ...)                        \
    Tf_Throw<Exception>(TF_CALL_CONTEXT, __VA_ARGS__)

#endif

PXR_NAMESPACE_CLOSE_SCOPE

#endif // PXR_BASE_TF_EXCEPTION_H