From 20622e74de6753c5e4460a112c11ee913707e8e8 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 10 Apr 2021 12:45:50 +0300
Subject: [PATCH] Make Tags convertible back to the original string in debug
 builds

This helps in producing more readable error messages
---
 source/render/tag.cpp | 41 +++++++++++++++++++++++++++++++++++++++--
 source/render/tag.h   |  6 ++++++
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/source/render/tag.cpp b/source/render/tag.cpp
index c5824aec..b5f86033 100644
--- a/source/render/tag.cpp
+++ b/source/render/tag.cpp
@@ -1,17 +1,54 @@
 #include <cstring>
+#include <map>
 #include <msp/core/hash.h>
+#include <msp/strings/format.h>
 #include "tag.h"
 
+using namespace std;
+
+namespace {
+
+#ifdef DEBUG
+map<Msp::GL::Tag, string> tag_names;
+#endif
+
+}
+
 namespace Msp {
 namespace GL {
 
 Tag::Tag(const char *s):
 	id((s && *s) ? hash32(s, strlen(s)) : 0)
-{ }
+{
+#ifdef DEBUG
+	if(s)
+		tag_names.insert(make_pair(*this, string(s)));
+#endif
+}
 
 Tag::Tag(const std::string &s):
 	id(s.empty() ? 0 : hash32(s))
-{ }
+{
+#ifdef DEBUG
+	if(!s.empty())
+		tag_names.insert(make_pair(*this, s));
+#endif
+}
+
+string Tag::str() const
+{
+#ifdef DEBUG
+	map<Tag, string>::const_iterator i=tag_names.find(*this);
+	if(i!=tag_names.end())
+		return i->second;
+#endif
+	return format("Tag(%d)", id);
+}
+
+void operator<<(LexicalConverter &conv, Tag tag)
+{
+	conv.result(tag.str());
+}
 
 } // namespace GL
 } // namespace Msp
diff --git a/source/render/tag.h b/source/render/tag.h
index 93808989..dbc0b3ef 100644
--- a/source/render/tag.h
+++ b/source/render/tag.h
@@ -2,6 +2,7 @@
 #define MSP_GL_TAG_H_
 
 #include <string>
+#include <msp/strings/lexicalcast.h>
 
 namespace Msp {
 namespace GL {
@@ -18,10 +19,15 @@ struct Tag
 	Tag(const char *);
 	Tag(const std::string &s);
 
+	std::string str() const;
+
 	bool operator<(Tag t) const { return id<t.id; }
 	bool operator==(Tag t) const { return id==t.id; }
+	bool operator!=(Tag t) const { return id!=t.id; }
 };
 
+void operator<<(LexicalConverter &, Tag);
+
 } // namespace GL
 } // namespace Msp
 
-- 
2.43.0