ircd: Add conf item to convey contextual diagnostic options.

construct/construct.cc

@@ -46,6 +46,7 @@ bool nomatrix;
 bool matrix {true}; // matrix server by default.
 bool defaults;
 const char *bootstrap;
+const char *diagnostic;
 
 lgetopt opts[]
 {
@@ -80,6 +81,7 @@ lgetopt opts[]
 	{ "matrix",     &matrix,        lgetopt::BOOL,    "Allow loading the matrix application module" },
 	{ "defaults",   &defaults,      lgetopt::BOOL,    "Use configuration defaults without database load for this execution" },
 	{ "bootstrap",  &bootstrap,     lgetopt::STRING,  "Bootstrap fresh database from event vector" },
+	{ "diagnostic", &diagnostic,    lgetopt::STRING,  "Specify a diagnostic type in conjunction with other commands" },
 	{ nullptr,      nullptr,        lgetopt::STRING,  nullptr },
 };
 
@@ -477,6 +479,9 @@ enable_coredumps()
 void
 applyargs()
 {
+	if(diagnostic)
+		ircd::diagnostic.set(diagnostic);
+
 	if(single && !bootstrap)
 	{
 		ircd::write_avoid.set("true");

include/ircd/ircd.h

@@ -111,6 +111,9 @@ namespace ircd
 	extern const info::versions version_api;
 	extern const info::versions version_abi;
 
+	// Diagnostic Mode Options
+	extern conf::item<std::string> diagnostic;
+
 	// Operating Mode Selectors
 	extern conf::item<bool> restart;
 	extern conf::item<bool> debugmode;

ircd/ircd.cc

@@ -140,6 +140,21 @@ ircd::read_only
 	}
 };
 
+/// Diagnostic options selection. This indicates whether any tests or special
+/// behavior should occur rather than normal operation; also allowing for
+/// fine-grained options to be conveyed to such tests/diagnostics. While this
+/// appears here as coarse library-wide option it does not on its own affect
+/// normal server operations just by being set. It affect things only if
+/// specific functionality checks and alters its behavior based on the value
+/// of this string contextually.
+decltype(ircd::diagnostic)
+ircd::diagnostic
+{
+	{ "name",     "ircd.diagnostic"     },
+	{ "default",  string_view{}         },
+	{ "persist",  false                 },
+};
+
 /// Main context pointer placement.
 decltype(ircd::main_context)
 ircd::main_context;