From 73d52ab92ce8da522cd2eeb0d7f13c6af3f46e02 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 12 Mar 2021 00:23:10 +0200
Subject: [PATCH] Improve reporting of errors from function resolution

If there are some overloads, report that none of them matched the
argument types.
---
 source/glsl/validate.cpp | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/source/glsl/validate.cpp b/source/glsl/validate.cpp
index 1458d01e..8805d41f 100644
--- a/source/glsl/validate.cpp
+++ b/source/glsl/validate.cpp
@@ -2,6 +2,7 @@
 #include <cstring>
 #include <msp/core/raii.h>
 #include <msp/strings/format.h>
+#include <msp/strings/utils.h>
 #include "validate.h"
 
 using namespace std;
@@ -239,7 +240,26 @@ void ReferenceValidator::visit(InterfaceBlockReference &iface)
 void ReferenceValidator::visit(FunctionCall &call)
 {
 	if(!call.declaration && !call.constructor)
-		error(call, format("Call to undeclared function '%s'", call.name));
+	{
+		map<string, FunctionDeclaration *>::iterator i = stage->functions.lower_bound(call.name);
+		if(i!=stage->functions.end() && i->second->name==call.name)
+		{
+			bool valid_types = true;
+			string signature;
+			for(NodeArray<Expression>::const_iterator j=call.arguments.begin(); (valid_types && j!=call.arguments.end()); ++j)
+			{
+				if((*j)->type)
+					append(signature, ", ", (*j)->type->name);
+				else
+					valid_types = false;
+			}
+
+			if(valid_types)
+				error(call, format("No matching overload found for call to '%s(%s)'", call.name, signature));
+		}
+		else
+			error(call, format("Call to undeclared function '%s'", call.name));
+	}
 	TraversingVisitor::visit(call);
 }
 
-- 
2.43.0