From c288e8d074f303f275ce03bf09c8799b2c8fde6e Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 8 Mar 2021 00:14:55 +0200
Subject: [PATCH] Report unsupported shader errors through the diagnostic
 mechanism

---
 source/glsl/compatibility.cpp | 28 +++++++++++++++++++++-------
 source/glsl/compatibility.h   |  2 ++
 source/glsl/glsl_error.h      |  7 -------
 3 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/source/glsl/compatibility.cpp b/source/glsl/compatibility.cpp
index 9ed0d20c..55fa30d9 100644
--- a/source/glsl/compatibility.cpp
+++ b/source/glsl/compatibility.cpp
@@ -88,9 +88,20 @@ void LegacyConverter::apply(Stage &s, const Features &feat)
 {
 	stage = &s;
 	features = feat;
-	if(!supports_stage(s.type))
-		throw unsupported_shader(format("Stage %s is not supported", Stage::get_stage_name(s.type)));
-	s.content.visit(*this);
+	if(supports_stage(s.type))
+		s.content.visit(*this);
+	else
+		unsupported(format("Stage %s is not supported", Stage::get_stage_name(s.type)));
+}
+
+void LegacyConverter::unsupported(const string &reason)
+{
+	Diagnostic diagnostic;
+	diagnostic.severity = Diagnostic::ERR;
+	diagnostic.source = GENERATED_SOURCE;
+	diagnostic.line = 0;
+	diagnostic.message = reason;
+	stage->diagnostics.push_back(diagnostic);
 }
 
 void LegacyConverter::visit(Block &block)
@@ -274,10 +285,13 @@ void LegacyConverter::visit(VariableDeclaration &var)
 			}
 			else if(stage->type==Stage::FRAGMENT && var.interface=="out")
 			{
-				if(i->value!=0 && !check_extension(&Features::ext_gpu_shader4))
-					throw unsupported_shader("EXT_gpu_shader4 is required");
-				stage->locations[var.name] = i->value;
-				var.layout->qualifiers.erase(i);
+				if(check_extension(&Features::ext_gpu_shader4))
+				{
+					stage->locations[var.name] = i->value;
+					var.layout->qualifiers.erase(i);
+				}
+				else if(i->value!=0)
+					unsupported("EXT_gpu_shader4 required for multiple fragment shader outputs");
 			}
 
 			if(var.layout->qualifiers.empty())
diff --git a/source/glsl/compatibility.h b/source/glsl/compatibility.h
index c30dce8c..21200713 100644
--- a/source/glsl/compatibility.h
+++ b/source/glsl/compatibility.h
@@ -61,6 +61,8 @@ public:
 	virtual void apply(Stage &, const Features &);
 
 private:
+	void unsupported(const std::string &);
+
 	virtual void visit(Block &);
 	bool check_version(const Version &) const;
 	bool check_extension(bool Features::*) const;
diff --git a/source/glsl/glsl_error.h b/source/glsl/glsl_error.h
index 1fd7169c..46854744 100644
--- a/source/glsl/glsl_error.h
+++ b/source/glsl/glsl_error.h
@@ -38,13 +38,6 @@ public:
 	virtual ~parse_error() throw() { }
 };
 
-class unsupported_shader: public std::runtime_error
-{
-public:
-	unsupported_shader(const std::string &w): runtime_error(w) { }
-	virtual ~unsupported_shader() throw() { }
-};
-
 struct Diagnostic
 {
 	enum Severity
-- 
2.43.0