From 853d94c3ef085c834f39ff8b5b867864b001654e Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sat, 9 Apr 2022 00:32:25 +0900
Subject: [PATCH] internal/shader: implement strict type checks when calling a
 function

Closes #2032
---
 internal/shader/expr.go        |  5 ++++
 internal/shader/syntax_test.go | 44 ++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/internal/shader/expr.go b/internal/shader/expr.go
index f53aff37d..d79ea28b6 100644
--- a/internal/shader/expr.go
+++ b/internal/shader/expr.go
@@ -444,6 +444,11 @@ func (cs *compileState) parseExpr(block *block, expr ast.Expr, markLocalVariable
 					return nil, nil, nil, false
 				}
 			}
+
+			if !canAssign(&args[i], &p, &argts[i]) {
+				cs.addError(e.Pos(), fmt.Sprintf("cannot use type %s as type %s in argument", argts[i].String(), p.String()))
+				return nil, nil, nil, false
+			}
 		}
 
 		var outParams []int
diff --git a/internal/shader/syntax_test.go b/internal/shader/syntax_test.go
index a1dee303c..be4265ed0 100644
--- a/internal/shader/syntax_test.go
+++ b/internal/shader/syntax_test.go
@@ -1307,3 +1307,47 @@ func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
 		t.Errorf("error must be non-nil but was nil")
 	}
 }
+
+// Issue #2032
+func TestSyntaxTypeFuncCall(t *testing.T) {
+	if _, err := compileToIR([]byte(`package main
+
+func Foo(x vec2) {
+}
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	Foo(0)
+	return color
+}
+`)); err == nil {
+		t.Errorf("error must be non-nil but was nil")
+	}
+	if _, err := compileToIR([]byte(`package main
+
+func Foo(x vec2, y vec3) {
+}
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	Foo(0, 1)
+	return color
+}
+`)); err == nil {
+		t.Errorf("error must be non-nil but was nil")
+	}
+	if _, err := compileToIR([]byte(`package main
+
+func Foo(x vec2, y vec3) {
+}
+
+func Bar() (int, int) {
+	return 0, 1
+}
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	Foo(Bar())
+	return color
+}
+`)); err == nil {
+		t.Errorf("error must be non-nil but was nil")
+	}
+}