Line data    Source code

       1            0 : // Distributed under the MIT License.
       2              : // See LICENSE.txt for details.
       3              : 
       4              : #pragma once
       5              : 
       6              : #include <ostream>
       7              : #include <vector>
       8              : 
       9              : namespace CaptureForError_detail {
      10              : class CaptureForErrorBase {
      11              :  protected:
      12              :   CaptureForErrorBase() = default;
      13              :   ~CaptureForErrorBase() = default;
      14              : 
      15              :  public:
      16              :   CaptureForErrorBase(CaptureForErrorBase&&) = delete;
      17              :   CaptureForErrorBase(const CaptureForErrorBase&) = delete;
      18              :   CaptureForErrorBase& operator=(CaptureForErrorBase&&) = delete;
      19              :   CaptureForErrorBase& operator=(const CaptureForErrorBase&) = delete;
      20              : 
      21              :   virtual void print(std::ostream& stream) const = 0;
      22              : };
      23              : 
      24              : class CaptureList {
      25              :  public:
      26              :   static CaptureList& the_list();
      27              : 
      28              :   void register_self(const CaptureForErrorBase* capture);
      29              :   void deregister_self(const CaptureForErrorBase* capture);
      30              : 
      31              :   void print(std::ostream& stream);
      32              : 
      33              :   CaptureList(CaptureList&&) = delete;
      34              :   CaptureList(const CaptureList&) = delete;
      35              :   CaptureList& operator=(CaptureList&&) = delete;
      36              :   CaptureList& operator=(const CaptureList&) = delete;
      37              : 
      38              :  private:
      39              :   CaptureList();
      40              :   ~CaptureList() noexcept(false);
      41              : 
      42              :   std::vector<const CaptureForErrorBase*> captures_{};
      43              :   bool currently_printing_ = false;
      44              : };
      45              : 
      46              : #pragma GCC diagnostic push
      47              : #pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
      48              : template <typename T>
      49              : // NOLINTNEXTLINE(cppcoreguidelines-virtual-class-destructor)
      50              : class CaptureForError : public CaptureForErrorBase {
      51              :  public:
      52              :   CaptureForError() = delete;
      53              :   CaptureForError(CaptureForError&&) = delete;
      54              :   CaptureForError(const CaptureForError&) = delete;
      55              :   CaptureForError& operator=(CaptureForError&&) = delete;
      56              :   CaptureForError& operator=(const CaptureForError&) = delete;
      57              : 
      58              :   CaptureForError(const char* const name, const T& capture)
      59              :       : name_(name), capture_(capture) {
      60              :     CaptureList::the_list().register_self(this);
      61              :   }
      62              : 
      63              :   // Capturing an rvalue would lead to a dangling reference.
      64              :   CaptureForError(const char* /*name*/, const T&& /*capture*/) = delete;
      65              : 
      66              :   ~CaptureForError() noexcept(false) {
      67              :     CaptureList::the_list().deregister_self(this);
      68              :   }
      69              : 
      70              :   void print(std::ostream& stream) const override {
      71              :     stream << name_ << " = " << capture_ << "\n";
      72              :   }
      73              : 
      74              :  private:
      75              :   const char* name_;
      76              :   const T& capture_;
      77              : };
      78              : #pragma GCC diagnostic pop
      79              : }  // namespace CaptureForError_detail
      80              : 
      81              : /// \cond
      82              : #define CAPTURE_FOR_ERROR_NAME2(line) capture_for_error_impl##line
      83              : #define CAPTURE_FOR_ERROR_NAME(line) CAPTURE_FOR_ERROR_NAME2(line)
      84              : /// \endcond
      85              : 
      86              : /*!
      87              :  * \brief Capture a variable to be printed on ERROR or ASSERT.
      88              :  *
      89              :  * The argument will be printed using its stream operator if an error
      90              :  * occurs before the end of the current scope.  The object is captured
      91              :  * by reference, so it must live until the end of the current scope,
      92              :  * and any subsequent changes to it will be reflected in the error
      93              :  * message.
      94              :  */
      95            1 : #define CAPTURE_FOR_ERROR(var)                                          \
      96              :   const CaptureForError_detail::CaptureForError CAPTURE_FOR_ERROR_NAME( \
      97              :       __LINE__)(#var, var)
      98              : 
      99              : /*!
     100              :  * \brief Stream all objects currently captured by CaptureForError.
     101              :  */
     102            1 : void print_captures_for_error(std::ostream& stream);