From 8ae6793d4d3c7c362f8b97165b730517c71cee74 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sun, 14 Nov 2021 17:34:06 +0900
Subject: [PATCH] internal/shader: Check the number of arguments

---
 internal/shader/expr.go                           |  9 +++++++++
 .../shader/testdata/call_multiple.expected.vs     |  2 +-
 internal/shader/testdata/call_multiple.go         |  2 +-
 shader_test.go                                    | 15 +++++++++++++++
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/internal/shader/expr.go b/internal/shader/expr.go
index 869726a9d..5e090ee51 100644
--- a/internal/shader/expr.go
+++ b/internal/shader/expr.go
@@ -291,6 +291,15 @@ func (cs *compileState) parseExpr(block *block, expr ast.Expr, markLocalVariable
 
 		f := cs.funcs[callee.Index]
 
+		if len(f.ir.InParams) < len(args) {
+			cs.addError(e.Pos(), fmt.Sprintf("too many arguments in call to %s", e.Fun))
+			return nil, nil, nil, false
+		}
+		if len(f.ir.InParams) > len(args) {
+			cs.addError(e.Pos(), fmt.Sprintf("not enough arguments in call to %s", e.Fun))
+			return nil, nil, nil, false
+		}
+
 		for i, p := range f.ir.InParams {
 			if args[i].Type == shaderir.NumberExpr && p.Main == shaderir.Int {
 				if !cs.forceToInt(e, &args[i]) {
diff --git a/internal/shader/testdata/call_multiple.expected.vs b/internal/shader/testdata/call_multiple.expected.vs
index cec73210d..6026d888c 100644
--- a/internal/shader/testdata/call_multiple.expected.vs
+++ b/internal/shader/testdata/call_multiple.expected.vs
@@ -6,7 +6,7 @@ void F0(in vec2 l0, out vec2 l1) {
 	float l3 = float(0);
 	float l4 = float(0);
 	float l5 = float(0);
-	F1((l0).x, (l0).y, l2, l3);
+	F1((l0).x, l2, l3);
 	l4 = l2;
 	l5 = l3;
 	l1 = vec2(l4, l5);
diff --git a/internal/shader/testdata/call_multiple.go b/internal/shader/testdata/call_multiple.go
index 9e33b3f20..d97c33c47 100644
--- a/internal/shader/testdata/call_multiple.go
+++ b/internal/shader/testdata/call_multiple.go
@@ -1,7 +1,7 @@
 package main
 
 func Foo(x vec2) vec2 {
-	var xx, yx float = Bar(x.x, x.y)
+	var xx, yx float = Bar(x.x)
 	return vec2(xx, yx)
 }
 
diff --git a/shader_test.go b/shader_test.go
index 643eb64c2..5b2735722 100644
--- a/shader_test.go
+++ b/shader_test.go
@@ -1180,3 +1180,18 @@ func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
 		})
 	}
 }
+
+func TestShaderUnmatchedArgs(t *testing.T) {
+	if _, err := ebiten.NewShader([]byte(`package main
+
+func Foo() {
+}
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	Foo(1)
+	return position
+}
+`)); err == nil {
+		t.Errorf("error must be non-nil but was nil")
+	}
+}