ircd::exception: Move throwing errno+system_category out-of-line.

include/ircd/exception.h

@@ -40,6 +40,7 @@ namespace ircd
 	std::system_error make_system_error(const std::error_code &);
 	std::system_error make_system_error(const boost::system::error_code &);
 	std::system_error make_system_error(const boost::system::system_error &);
+	[[noreturn]] void throw_system_error();
 	template<class... args> std::exception_ptr make_system_eptr(args&&...);
 	template<class... args> [[noreturn]] void throw_system_error(args&&...);
 	template<class E, class... args> std::exception_ptr make_exception_ptr(args&&...);

include/ircd/sys.h

@@ -107,10 +107,7 @@ ircd::sys::call(function&& f,
 	};
 
 	if(unlikely(!nothrow && ret == -1L))
-		throw std::system_error
-		{
-			errno, std::system_category()
-		};
+		throw_system_error();
 
 	return ret;
 }

ircd/allocator.cc

@@ -63,10 +63,8 @@ ircd::allocator::allocate(const size_t alignment,
 			throw std::bad_alloc{};
 
 		default:
-			throw std::system_error
-			{
-				errc, std::system_category()
-			};
+			throw_system_error();
+			__builtin_unreachable();
 	}
 
 	assert(ret != nullptr);

ircd/exception.cc

@@ -152,6 +152,16 @@ noexcept
 	       ec == boost::system::generic_category();
 }
 
+[[noreturn]]
+void
+ircd::throw_system_error()
+{
+    throw std::system_error
+    {
+		errno, std::system_category()
+    };
+}
+
 std::system_error
 ircd::make_system_error(const boost::system::system_error &e)
 {

ircd/fs.cc

@@ -1022,10 +1022,7 @@ ircd::fs::_read_preadv(const fd &fd,
 		return 0UL;
 
 	if(unlikely(ret == -1))
-		throw std::system_error
-		{
-			errno, std::system_category()
-		};
+		throw_system_error();
 
 	return ret;
 }
@@ -1052,10 +1049,7 @@ ircd::fs::_read_preadv2(const fd &fd,
 		return 0UL;
 
 	if(unlikely(ret == -1))
-		throw std::system_error
-		{
-			errno, std::system_category()
-		};
+		throw_system_error();
 
 	return ret;
 }
@@ -1407,10 +1401,7 @@ ircd::fs::_write_pwritev(const fd &fd,
 		return 0UL;
 
 	if(unlikely(ret == -1))
-		throw std::system_error
-		{
-			errno, std::system_category()
-		};
+		throw_system_error();
 
 	return ret;
 }
@@ -1440,10 +1431,7 @@ ircd::fs::_write_pwritev2(const fd &fd,
 		return 0UL;
 
 	if(unlikely(ret == -1))
-		throw std::system_error
-		{
-			errno, std::system_category()
-		};
+		throw_system_error();
 
 	return ret;
 }

ircd/prof_linux.cc

@@ -432,10 +432,7 @@ ircd::prof::event::event(const int &group,
 	};
 
 	if(ret == (void *)-1)
-		throw std::system_error
-		{
-			errno, std::system_category()
-		};
+		throw_system_error();
 
 	if(map_size && ret == nullptr)
 		throw error