src/library/exrethrow.cpp

   1 #include "exrethrow.hpp"
   2 #include <list>
   3 #include <iostream>
   4 #include <future>
   5
   6 namespace exrethrow
   7 {
   8 ex_spec<std::exception, 0> std_exception;
   9 ex_spec<std::logic_error, 1> std_logic_error;
  10 ex_spec<std::domain_error, 2> std_domain_error;
  11 ex_spec<std::invalid_argument, 2> std_invalid_argument;
  12 ex_spec<std::length_error, 2> std_length_error;
  13 ex_spec<std::out_of_range, 2> std_out_of_range;
  14 ex_spec<std::future_error, 2> std_future_error;
  15 ex_spec<std::runtime_error, 1> std_runtime_error;
  16 ex_spec<std::range_error, 2> std_range_error;
  17 ex_spec<std::overflow_error, 2> std_overflow_error;
  18 ex_spec<std::underflow_error, 2> std_underflow_error;
  19 ex_spec<std::system_error, 2> std_system_error;
  20 ex_spec<std::bad_cast, 1> std_bad_cast;
  21 ex_spec<std::bad_exception, 1> std_bad_exception;
  22 ex_spec<std::bad_function_call, 1> std_bad_function_call;
  23 ex_spec<std::bad_typeid, 1> std_bad_typeid;
  24 ex_spec<std::bad_weak_ptr, 1> std_bad_weak_ptr;
  25 ex_spec<std::ios_base::failure, 1> std_ios_base_failure;
  26
  27 struct exspec_item {
  28         unsigned prio;
  29         std::function<bool(std::exception& e)> identify;
  30         std::function<void()> (*throwfn)(std::exception& e);
  31 };
  32 std::list<exspec_item>* exspecs;
  33
  34 void add_ex_spec(unsigned prio, std::function<bool(std::exception& e)> identify,
  35         std::function<void()> (*throwfn)(std::exception& e))
  36 {
  37         exspec_item i;
  38         i.prio = prio;
  39         i.identify = identify;
  40         i.throwfn = throwfn;
  41         if(!exspecs)
  42                 exspecs = new std::list<exspec_item>;
  43         for(auto j = exspecs->begin(); j != exspecs->end(); j++) {
  44                 if(j->prio <= prio) {
  45                         exspecs->insert(j, i);
  46                         return;
  47                 }
  48         }
  49         exspecs->push_back(i);
  50 }
  51
  52 std::function<void()> get_throw_fn(std::exception& e)
  53 {
  54         for(auto& i : *exspecs) {
  55                 if(i.identify(e))
  56                         return i.throwfn(e);
  57         }
  58         return []() -> void { throw std::runtime_error("Unknown exception"); };
  59 }
  60
  61 storage::storage()
  62 {
  63         null = true;
  64 }
  65
  66 storage::storage(std::exception& e)
  67 {
  68         null = false;
  69         oom = false;
  70         if(dynamic_cast<std::bad_alloc*>(&e)) {
  71                 oom = true;
  72                 return;
  73         }
  74         try {
  75                 do_rethrow = get_throw_fn(e);
  76         } catch(...) {
  77                 oom = true;
  78         }
  79 }
  80
  81 void storage::rethrow()
  82 {
  83         if(null) return;
  84         if(oom)
  85                 throw std::bad_alloc();
  86         do_rethrow();
  87 }
  88
  89 storage::operator bool()
  90 {
  91         return !null;
  92 }
  93 }