From bf388e5428fff3dc4d72a07549569863ef71bb93 Mon Sep 17 00:00:00 2001
From: Nekotekina <nekotekina@gmail.com>
Date: Thu, 24 Nov 2022 17:17:46 +0300
Subject: [PATCH] cfmt/StrFmt: support s128 formatting (untested)

---
 Utilities/StrFmt.cpp |  5 +++--
 Utilities/cfmt.h     | 53 +++++++++++++++++++++++++++-----------------
 2 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/Utilities/StrFmt.cpp b/Utilities/StrFmt.cpp
index 277a3470cd..b9a2084095 100644
--- a/Utilities/StrFmt.cpp
+++ b/Utilities/StrFmt.cpp
@@ -449,7 +449,7 @@ struct fmt::cfmt_src
 	{
 // Hack: use known function pointers to determine type
 #define TYPE(type) \
-	if (sup[extra].fmt_string == &fmt_class_string<type>::format) return sizeof(type);
+		if (sup[extra].fmt_string == &fmt_class_string<type>::format) return sizeof(type);
 
 		TYPE(int);
 		TYPE(llong);
@@ -457,10 +457,11 @@ struct fmt::cfmt_src
 		TYPE(short);
 		if (std::is_signed<char>::value) TYPE(char);
 		TYPE(long);
-		TYPE(u128);
 		TYPE(s128);
 
 #undef TYPE
+		if (sup[extra].fmt_string == &fmt_class_string<u128>::format)
+			return -1;
 
 		return 0;
 	}
diff --git a/Utilities/cfmt.h b/Utilities/cfmt.h
index 4d4067d9e6..3b2c94dcbc 100644
--- a/Utilities/cfmt.h
+++ b/Utilities/cfmt.h
@@ -367,9 +367,11 @@ usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 			break;
 		}
 
-		if (!ctx.type)
+		const usz src_type = src.type(ctx.args);
+
+		if (!ctx.type || src_type > 8)
 		{
-			ctx.type = static_cast<u8>(src.type(ctx.args));
+			ctx.type = static_cast<u8>(src_type);
 
 			if (!ctx.type)
 			{
@@ -379,7 +381,13 @@ usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 
 		// Sign-extended argument expected
 		const u64 val = src.template get<u64>(ctx.args);
-		const bool negative = ctx.type && static_cast<s64>(val) < 0;
+		bool negative = ctx.type && ctx.type <= 8 && static_cast<s64>(val) < 0;
+
+		if (ctx.type == 16)
+		{
+			u128 val2 = *reinterpret_cast<const u128*>(val);
+			negative = !!(val2 & (u128{1} << 127));
+		}
 
 		const usz start = out.size();
 
@@ -398,15 +406,14 @@ usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 				out.push_back(' ');
 			}
 
-			if (ctx.type == 16)
+			if (ctx.type >= 16)
 			{
-				// TODO: support negative values (s128)
-				u128 val2 = *reinterpret_cast<u128*>(val);
-				write_decimal(val2, ctx.prec);
+				u128 val2 = *reinterpret_cast<const u128*>(val);
+				write_decimal(negative ? u128{} - val2 : val2, ctx.prec);
 			}
 			else
 			{
-				write_decimal(negative ? 0 - val : val, ctx.prec);
+				write_decimal(negative ? u64{} - val : val, ctx.prec);
 			}
 		}
 
@@ -438,9 +445,11 @@ usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 			break;
 		}
 
-		if (!ctx.type)
+		const usz src_type = src.type(ctx.args);
+
+		if (!ctx.type || src_type > 8)
 		{
-			ctx.type = static_cast<u8>(src.type(ctx.args));
+			ctx.type = static_cast<u8>(src_type);
 
 			if (!ctx.type)
 			{
@@ -471,9 +480,9 @@ usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 
 		if ((ctx.alter && val) || !ctx.dot || ctx.prec)
 		{
-			if (ctx.type == 16)
+			if (ctx.type >= 16)
 			{
-				u128 val2 = *reinterpret_cast<u128*>(val);
+				u128 val2 = *reinterpret_cast<const u128*>(val);
 				write_octal(val2, ctx.prec);
 			}
 			else
@@ -504,9 +513,11 @@ usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 			break;
 		}
 
-		if (!ctx.type)
+		const usz src_type = src.type(ctx.args);
+
+		if (!ctx.type || src_type > 8)
 		{
-			ctx.type = static_cast<u8>(src.type(ctx.args));
+			ctx.type = static_cast<u8>(src_type);
 
 			if (!ctx.type)
 			{
@@ -537,9 +548,9 @@ usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 
 		if ((ctx.alter && val) || !ctx.dot || ctx.prec)
 		{
-			if (ctx.type == 16)
+			if (ctx.type >= 16)
 			{
-				u128 val2 = *reinterpret_cast<u128*>(val);
+				u128 val2 = *reinterpret_cast<const u128*>(val);
 				write_hex(val2, ch == 'X', ctx.prec);
 			}
 			else
@@ -576,9 +587,11 @@ usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 			break;
 		}
 
-		if (!ctx.type)
+		const usz src_type = src.type(ctx.args);
+
+		if (!ctx.type || src_type > 8)
 		{
-			ctx.type = static_cast<u8>(src.type(ctx.args));
+			ctx.type = static_cast<u8>(src_type);
 
 			if (!ctx.type)
 			{
@@ -599,9 +612,9 @@ usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 
 		if (!ctx.dot || ctx.prec)
 		{
-			if (ctx.type == 16)
+			if (ctx.type >= 16)
 			{
-				u128 val2 = *reinterpret_cast<u128*>(val);
+				u128 val2 = *reinterpret_cast<const u128*>(val);
 				write_decimal(val2, ctx.prec);
 			}
 			else