ircd: Add ircd::assertion and exception suite for assertive errors.

include/ircd/exception.h

@@ -28,6 +28,7 @@
 
 namespace ircd
 {
+	// Root exception
 	struct exception;
 
 	// Prefer ircd::terminate() to std::terminate() if possible.
@@ -35,6 +36,11 @@ namespace ircd
 	[[noreturn]] void terminate(std::exception_ptr) noexcept;
 	[[noreturn]] void terminate() noexcept;
 
+	// Terminates in debug mode; throws in release mode; always logs critical.
+	[[noreturn]] void assertion(const std::exception &) noexcept(RB_DEBUG);
+	[[noreturn]] void assertion(std::exception_ptr) noexcept(RB_DEBUG);
+	[[noreturn]] void assertion() noexcept(RB_DEBUG);
+
 	// Can be used to clobber the std::terminate_handler
 	void aborting() noexcept;
 }
@@ -147,6 +153,31 @@ struct name                                                                   \
     }                                                                         \
 };
 
+/// Creates an assertion-type exception.
+///
+/// Throwable exception which will terminate on construction in debug mode
+/// but throw normally in release mode. Ideally this should never be thrown
+/// in release mode because the termination in debug means a test can never
+/// pass and the triggering callsite should be eliminated. Nevertheless it
+/// throws normally in release mode.
+#define IRCD_ASSERTION(parent, name)                                          \
+struct name                                                                   \
+:parent                                                                       \
+{                                                                             \
+    template<class... args>                                                   \
+    name(const char *const &fmt = " ", args&&... ap) noexcept(RB_DEBUG)       \
+    :parent{generate_skip}                                                    \
+    {                                                                         \
+        generate(#name, fmt, va_rtti{std::forward<args>(ap)...});             \
+        ircd::assertion(*this);                                               \
+    }                                                                         \
+                                                                              \
+    name(generate_skip_t) noexcept(RB_DEBUG)                                  \
+    :parent{generate_skip}                                                    \
+    {                                                                         \
+    }                                                                         \
+};                                                                            \
+
 namespace ircd
 {
 	/// Root error exception type. Inherit from this.
@@ -157,4 +188,8 @@ namespace ircd
 	///
 	IRCD_EXCEPTION(exception, error)             // throw ircd::error("something bad")
 	IRCD_EXCEPTION(error, user_error)            // throw ircd::user_error("something silly")
+
+	// Assertion errors; see IRCD_ASSERTION docs.
+	IRCD_ASSERTION(exception, assertive)
+	IRCD_ASSERTION(assertive, not_implemented)
 }

ircd/exception.cc

@@ -47,6 +47,44 @@ noexcept
 	return size;
 }
 
+void
+ircd::assertion()
+noexcept(RB_DEBUG)
+{
+	if(std::uncaught_exceptions())
+	{
+		assertion(std::current_exception());
+	} else {
+		log::critical("IRCd Assertion without active exception.");
+		assert(0);
+		throw assertive{};
+	}
+}
+
+void
+ircd::assertion(std::exception_ptr eptr)
+noexcept(RB_DEBUG) try
+{
+	std::rethrow_exception(eptr);
+}
+catch(const std::exception &e)
+{
+	assertion(e);
+}
+
+void
+ircd::assertion(const std::exception &e)
+noexcept(RB_DEBUG)
+{
+	log::critical("IRCd Assertion %s", e.what());
+
+	#ifdef RB_DEBUG
+		terminate(e);
+	#else
+		throw e;
+	#endif
+}
+
 void
 ircd::terminate()
 noexcept
@@ -76,7 +114,7 @@ ircd::terminate(const std::exception &e)
 noexcept
 {
 	log::critical("IRCd Terminated: %s", e.what());
-	std::terminate();
+	throw e;
 }
 
 [[noreturn]] static void