From abcd1fa06f9fab27c5934b4069523dd009862b18 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 3 Sep 2022 14:33:43 +0300
Subject: [PATCH] Validate the presence of in/out layout qualifiers for
 geometry shaders

Builtin arrays are now always autosized, even when the appropriate size
isn't known, because the error message from the missing size is confusing.
---
 source/glsl/generate.cpp                 |  2 +-
 source/glsl/validate.cpp                 | 36 ++++++++++++++++++++++++
 source/glsl/validate.h                   |  3 ++
 tests/glsl/missing_geometry_layouts.glsl | 22 +++++++++++++++
 4 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 tests/glsl/missing_geometry_layouts.glsl

diff --git a/source/glsl/generate.cpp b/source/glsl/generate.cpp
index 99253fe0..e4830ec2 100644
--- a/source/glsl/generate.cpp
+++ b/source/glsl/generate.cpp
@@ -350,7 +350,7 @@ void ArraySizer::apply(Stage &stage)
 				size = input_size;
 			else if(kvp.second>=0)
 				size = kvp.second+1;
-			else if(!kvp.first->name.compare(0, 3, "gl_"))
+			if(!size && !kvp.first->name.compare(0, 3, "gl_"))
 				size = 1;
 
 			if(size>0)
diff --git a/source/glsl/validate.cpp b/source/glsl/validate.cpp
index d669b237..4c135892 100644
--- a/source/glsl/validate.cpp
+++ b/source/glsl/validate.cpp
@@ -39,6 +39,27 @@ void DeclarationValidator::apply(Stage &s, const Features &f)
 	stage = &s;
 	features = f;
 	s.content.visit(*this);
+
+	Node *global_err_node = 0;
+	auto i = s.functions.find("main()");
+	if(i!=s.functions.end())
+		global_err_node = i->second;
+	else
+	{
+		for(auto j=s.content.body.begin(); (!global_err_node && j!=s.content.body.end()); ++j)
+			if((*j)->source>0)
+				global_err_node = j->get();
+	}
+
+	if(s.type==Stage::GEOMETRY)
+	{
+		if(!have_input_primitive)
+			error(*global_err_node, "No primitive type qualifier found on input");
+		if(!have_output_primitive)
+			error(*global_err_node, "No primitive type qualifier found on output");
+		if(!have_output_vertex_count)
+			error(*global_err_node, "No vertex count qualifier found on output");
+	}
 }
 
 const char *DeclarationValidator::describe_variable(ScopeType scope)
@@ -118,21 +139,36 @@ void DeclarationValidator::visit(Layout &layout)
 		{
 			allowed = (stage->type==Stage::GEOMETRY && iface_layout && (iface_layout->interface=="in" || iface_layout->interface=="out"));
 			value = false;
+			if(allowed)
+			{
+				if(iface_layout->interface=="in")
+					have_input_primitive = true;
+				else if(iface_layout->interface=="out")
+					have_output_primitive = true;
+			}
 		}
 		else if(q.name=="lines" || q.name=="lines_adjacency" || q.name=="triangles" || q.name=="triangles_adjacency")
 		{
 			allowed = (stage->type==Stage::GEOMETRY && iface_layout && iface_layout->interface=="in");
 			value = false;
+			if(allowed)
+				have_input_primitive = true;
 		}
 		else if(q.name=="line_strip" || q.name=="triangle_strip")
 		{
 			allowed = (stage->type==Stage::GEOMETRY && iface_layout && iface_layout->interface=="out");
 			value = false;
+			if(allowed)
+				have_output_primitive = true;
 		}
 		else if(q.name=="invocations")
 			allowed = (stage->type==Stage::GEOMETRY && iface_layout && iface_layout->interface=="in");
 		else if(q.name=="max_vertices")
+		{
 			allowed = (stage->type==Stage::GEOMETRY && iface_layout && iface_layout->interface=="out");
+			if(allowed)
+				have_output_vertex_count = true;
+		}
 		else if(q.name=="std140" || q.name=="std430")
 		{
 			allowed = (iface_block && !variable && iface_block->interface=="uniform");
diff --git a/source/glsl/validate.h b/source/glsl/validate.h
index c9a7b736..f5620435 100644
--- a/source/glsl/validate.h
+++ b/source/glsl/validate.h
@@ -44,6 +44,9 @@ private:
 	InterfaceLayout *iface_layout = 0;
 	VariableDeclaration *iface_block = 0;
 	VariableDeclaration *variable = 0;
+	bool have_input_primitive = false;
+	bool have_output_primitive = false;
+	bool have_output_vertex_count = false;
 
 public:
 	void apply(Stage &, const Features &);
diff --git a/tests/glsl/missing_geometry_layouts.glsl b/tests/glsl/missing_geometry_layouts.glsl
new file mode 100644
index 00000000..b531e8ed
--- /dev/null
+++ b/tests/glsl/missing_geometry_layouts.glsl
@@ -0,0 +1,22 @@
+#pragma MSP stage(vertex)
+layout(location=0) in vec4 position;
+void main()
+{
+	gl_Position = position;
+}
+
+#pragma MSP stage(geometry)
+void main()
+{
+	for(int i=0; i<3; ++i)
+	{
+		passthrough[i];
+		EmitVertex();
+	}
+}
+
+/* Expected error:
+<test>:9: No primitive type qualifier found on input
+<test>:9: No primitive type qualifier found on output
+<test>:9: No vertex count qualifier found on output
+*/
-- 
2.43.0