internal/shader: Check the number of arguments

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]) {

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);

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)
 }
 

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")
+	}
+}