From a99ac62c1ab816ee48cac85fdf834f9fdc599cb1 Mon Sep 17 00:00:00 2001
From: rubidium42 <rubidium@openttd.org>
Date: Fri, 11 Jun 2021 21:17:07 +0200
Subject: [PATCH] Codechange: use the fmt library for simpler debug formats

---
 src/debug.cpp |  2 +-
 src/debug.h   | 11 +++++++++++
 src/stdafx.h  |  3 +++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/debug.cpp b/src/debug.cpp
index 39c695e036..cfcb0ee8b2 100644
--- a/src/debug.cpp
+++ b/src/debug.cpp
@@ -103,7 +103,7 @@ char *DumpDebugFacilityNames(char *buf, char *last)
  * @param dbg Debug category.
  * @param buf Text line to output.
  */
-static void debug_print(const char *dbg, const char *buf)
+void debug_print(const char *dbg, const char *buf)
 {
 	if (_debug_socket != INVALID_SOCKET) {
 		char buf2[1024 + 32];
diff --git a/src/debug.h b/src/debug.h
index 29a7114aa0..8923e706bc 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -12,6 +12,7 @@
 
 #include "cpu.h"
 #include <chrono>
+#include "3rdparty/fmt/format.h"
 
 /* Debugging messages policy:
  * These should be the severities used for direct DEBUG() calls
@@ -27,6 +28,16 @@
  * 6.. - extremely detailed spamming
  */
 
+void debug_print(const char *dbg, const char *buf);
+
+/**
+ * Ouptut a line of debugging information.
+ * @param name The category of debug information.
+ * @param level The maximum debug level this message should be shown at. When the debug level for this category is set lower, then the message will not be shown.
+ * @param format_string The formatting string of the message.
+ */
+#define Debug(name, level, format_string, ...) if ((level) == 0 || _debug_ ## name ## _level >= (level)) debug_print(#name, fmt::format(FMT_STRING(format_string), ## __VA_ARGS__).c_str())
+
 /**
  * Output a line of debugging information.
  * @param name Category
diff --git a/src/stdafx.h b/src/stdafx.h
index e593344bf4..effd57caea 100644
--- a/src/stdafx.h
+++ b/src/stdafx.h
@@ -425,6 +425,9 @@ static_assert(SIZE_MAX >= UINT32_MAX);
 #	define unlikely(x) (x)
 #endif /* __GNUC__ || __clang__ */
 
+/* For the FMT library we only want to use the headers, not link to some library. */
+#define FMT_HEADER_ONLY
+
 void NORETURN CDECL usererror(const char *str, ...) WARN_FORMAT(1, 2);
 void NORETURN CDECL error(const char *str, ...) WARN_FORMAT(1, 2);
 #define NOT_REACHED() error("NOT_REACHED triggered at line %i of %s", __LINE__, __FILE__)