src/library/exrethrow.cpp

   1 #include "exrethrow.hpp"
   2 #include <functional>
   3 #include <list>
   4 #include <iostream>
   5 #include <future>
   6
   7 namespace exrethrow
   8 {
   9 ex_spec<std::exception, 0> std_exception;
  10 ex_spec<std::logic_error, 1> std_logic_error;
  11 ex_spec<std::domain_error, 2> std_domain_error;
  12 ex_spec<std::invalid_argument, 2> std_invalid_argument;
  13 ex_spec<std::length_error, 2> std_length_error;
  14 ex_spec<std::out_of_range, 2> std_out_of_range;
  15 ex_spec<std::future_error, 2> std_future_error;
  16 ex_spec<std::runtime_error, 1> std_runtime_error;
  17 ex_spec<std::range_error, 2> std_range_error;
  18 ex_spec<std::overflow_error, 2> std_overflow_error;
  19 ex_spec<std::underflow_error, 2> std_underflow_error;
  20 ex_spec<std::system_error, 2> std_system_error;
  21 ex_spec<std::bad_cast, 1> std_bad_cast;
  22 ex_spec<std::bad_exception, 1> std_bad_exception;
  23 ex_spec<std::bad_function_call, 1> std_bad_function_call;
  24 ex_spec<std::bad_typeid, 1> std_bad_typeid;
  25 ex_spec<std::bad_weak_ptr, 1> std_bad_weak_ptr;
  26 ex_spec<std::ios_base::failure, 1> std_ios_base_failure;
  27
  28 struct exspec_item {
  29         unsigned prio;
  30         std::function<bool(std::exception& e)> identify;
  31         std::function<void()> (*throwfn)(std::exception& e);
  32 };
  33 std::list<exspec_item>* exspecs;
  34
  35 void add_ex_spec(unsigned prio, std::function<bool(std::exception& e)> identify,
  36         std::function<void()> (*throwfn)(std::exception& e))
  37 {
  38         exspec_item i;
  39         i.prio = prio;
  40         i.identify = identify;
  41         i.throwfn = throwfn;
  42         if(!exspecs)
  43                 exspecs = new std::list<exspec_item>;
  44         for(auto j = exspecs->begin(); j != exspecs->end(); j++) {
  45                 if(j->prio <= prio) {
  46                         exspecs->insert(j, i);
  47                         return;
  48                 }
  49         }
  50         exspecs->push_back(i);
  51 }
  52
  53 std::function<void()> get_throw_fn(std::exception& e)
  54 {
  55         for(auto& i : *exspecs) {
  56                 if(i.identify(e))
  57                         return i.throwfn(e);
  58         }
  59         return []() -> void { throw std::runtime_error("Unknown exception"); };
  60 }
  61
  62 storage::storage()
  63 {
  64         null = true;
  65 }
  66
  67 storage::storage(std::exception& e)
  68 {
  69         null = false;
  70         oom = false;
  71         if(dynamic_cast<std::bad_alloc*>(&e)) {
  72                 oom = true;
  73                 return;
  74         }
  75         try {
  76                 do_rethrow = get_throw_fn(e);
  77         } catch(...) {
  78                 oom = true;
  79         }
  80 }
  81
  82 void storage::rethrow()
  83 {
  84         if(null) return;
  85         if(oom)
  86                 throw std::bad_alloc();
  87         do_rethrow();
  88 }
  89
  90 storage::operator bool()
  91 {
  92         return !null;
  93 }
  94 }