From 064f0b712c783c8c1638c4be674e1a633a0a78e9 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Fri, 19 Jul 2019 17:03:58 -0700
Subject: [PATCH] ircd::log: Fixes for clang DCE.

---
 include/ircd/ctx/slice_usage_warning.h |  13 +++-
 include/ircd/logger.h                  | 101 +++++++++++++++++++++++++
 2 files changed, 110 insertions(+), 4 deletions(-)

diff --git a/include/ircd/ctx/slice_usage_warning.h b/include/ircd/ctx/slice_usage_warning.h
index 22aac5b46..5b2eb6ecf 100644
--- a/include/ircd/ctx/slice_usage_warning.h
+++ b/include/ircd/ctx/slice_usage_warning.h
@@ -35,10 +35,15 @@ struct ircd::ctx::this_ctx::slice_usage_warning
 #else
 struct ircd::ctx::this_ctx::slice_usage_warning
 {
+	#if defined(__clang__)
+	template<class... args>
+	slice_usage_warning(const string_view &fmt, args&&...)
+	{}
+	#else
+	// In at least gcc 6.3.0 20170519, template param packs are not DCE'ed
+	// so legacy varargs are used here.
 	slice_usage_warning(const string_view &fmt, ...)
-	{
-		// In at least gcc 6.3.0 20170519, template param packs are not DCE'ed
-		// so legacy varargs are used here.
-	}
+	{}
+	#endif
 };
 #endif
diff --git a/include/ircd/logger.h b/include/ircd/logger.h
index 4f1e228ef..4b98b0479 100644
--- a/include/ircd/logger.h
+++ b/include/ircd/logger.h
@@ -196,6 +196,19 @@ struct ircd::log::debug
 		vlog(general, level::DEBUG, fmt, va_rtti{std::forward<args>(a)...});
 	}
 };
+#elif defined(__clang__)
+struct ircd::log::debug
+{
+	template<class... args>
+	debug(const log &log, const string_view &fmt, args&&... a)
+	{
+	}
+
+	template<class... args>
+	debug(const string_view &fmt, args&&... a)
+	{
+	}
+};
 #else
 struct ircd::log::debug
 {
@@ -226,6 +239,19 @@ struct ircd::log::dwarning
 		vlog(general, level::DWARNING, fmt, va_rtti{std::forward<args>(a)...});
 	}
 };
+#elif defined(__clang__)
+struct ircd::log::dwarning
+{
+	template<class... args>
+	dwarning(const log &log, const string_view &fmt, args&&... a)
+	{
+	}
+
+	template<class... args>
+	dwarning(const string_view &fmt, args&&... a)
+	{
+	}
+};
 #else
 struct ircd::log::dwarning
 {
@@ -256,6 +282,19 @@ struct ircd::log::derror
 		vlog(general, level::DERROR, fmt, va_rtti{std::forward<args>(a)...});
 	}
 };
+#elif defined(__clang__)
+struct ircd::log::derror
+{
+	template<class... args>
+	derror(const log &log, const string_view &fmt, args&&... a)
+	{
+	}
+
+	template<class... args>
+	derror(const string_view &fmt, args&&... a)
+	{
+	}
+};
 #else
 struct ircd::log::derror
 {
@@ -286,6 +325,19 @@ struct ircd::log::info
 		vlog(general, level::INFO, fmt, va_rtti{std::forward<args>(a)...});
 	}
 };
+#elif defined(__clang__)
+struct ircd::log::info
+{
+	template<class... args>
+	info(const log &log, const string_view &fmt, args&&... a)
+	{
+	}
+
+	template<class... args>
+	info(const string_view &fmt, args&&... a)
+	{
+	}
+};
 #else
 struct ircd::log::info
 {
@@ -316,6 +368,16 @@ struct ircd::log::notice
 		vlog(general, level::NOTICE, fmt, va_rtti{std::forward<args>(a)...});
 	}
 };
+#elif defined(__clang__)
+	template<class... args>
+	notice(const log &log, const string_view &fmt, args&&... a)
+	{
+	}
+
+	template<class... args>
+	notice(const string_view &fmt, args&&... a)
+	{
+	}
 #else
 struct ircd::log::notice
 {
@@ -346,6 +408,19 @@ struct ircd::log::warning
 		vlog(general, level::WARNING, fmt, va_rtti{std::forward<args>(a)...});
 	}
 };
+#elif defined(__clang__)
+struct ircd::log::warning
+{
+	template<class... args>
+	warning(const log &log, const string_view &fmt, args&&... a)
+	{
+	}
+
+	template<class... args>
+	warning(const string_view &fmt, args&&... a)
+	{
+	}
+};
 #else
 struct ircd::log::warning
 {
@@ -376,6 +451,19 @@ struct ircd::log::error
 		vlog(general, level::ERROR, fmt, va_rtti{std::forward<args>(a)...});
 	}
 };
+#elif defined(__clang__)
+struct ircd::log::error
+{
+	template<class... args>
+	error(const log &log, const string_view &fmt, args&&... a)
+	{
+	}
+
+	template<class... args>
+	error(const string_view &fmt, args&&... a)
+	{
+	}
+};
 #else
 struct ircd::log::error
 {
@@ -435,6 +523,19 @@ struct ircd::log::critical
 		vlog(general, level::CRITICAL, fmt, va_rtti{std::forward<args>(a)...});
 	}
 };
+#elif defined(__clang__)
+struct ircd::log::critical
+{
+	template<class... args>
+	critical(const log &log, const string_view &fmt, args&&... a)
+	{
+	}
+
+	template<class... args>
+	critical(const string_view &fmt, args&&... a)
+	{
+	}
+};
 #else
 struct ircd::log::critical
 {