checker: fix missing unwrap check for option to non-option argument (#18460)

vlib/v/checker/check_types.v

@@ -234,6 +234,12 @@ fn (mut c Checker) check_expected_call_arg(got ast.Type, expected_ ast.Type, lan
 			got_typ_str, expected_typ_str := c.get_string_names_of(got, expected)
 			return error('cannot use `${got_typ_str}` as `${expected_typ_str}`')
 		}
+
+		if !expected.has_flag(.option) && got.has_flag(.option) && (arg.expr !is ast.Ident
+			|| (arg.expr is ast.Ident && c.get_ct_type_var(arg.expr) != .field_var)) {
+			got_typ_str, expected_typ_str := c.get_string_names_of(got, expected)
+			return error('cannot use `${got_typ_str}` as `${expected_typ_str}`, it must be unwrapped first')
+		}
 	}
 	// check int signed/unsigned mismatch
 	if got == ast.int_literal_type_idx && expected in ast.unsigned_integer_type_idxs

vlib/v/checker/comptime.v

@@ -9,6 +9,15 @@ import v.token
 import v.util
 import v.pkgconfig
 
+[inline]
+fn (mut c Checker) get_ct_type_var(node ast.Expr) ast.ComptimeVarKind {
+	return if node is ast.Ident && (node as ast.Ident).obj is ast.Var {
+		(node.obj as ast.Var).ct_type_var
+	} else {
+		.no_comptime
+	}
+}
+
 [inline]
 fn (mut c Checker) get_comptime_var_type(node ast.Expr) ast.Type {
 	if node is ast.Ident && (node as ast.Ident).obj is ast.Var {

vlib/v/checker/tests/option_fn_err.out

@@ -1,3 +1,17 @@
+vlib/v/checker/tests/option_fn_err.vv:34:16: error: cannot use `?int` as `int`, it must be unwrapped first in argument 1 to `twice`
+   32 |     foo()
+   33 |     _ := bar(0)
+   34 |     println(twice(bar(0)))
+      |                   ~~~~~~
+   35 | 
+   36 |     // anon fn
+vlib/v/checker/tests/option_fn_err.vv:37:16: error: cannot use `?int` as `int`, it must be unwrapped first in argument 1 to `anon`
+   35 | 
+   36 |     // anon fn
+   37 |     fn (_ int) {}(bar(0))
+      |                   ~~~~~~
+   38 | 
+   39 |     // assert
 vlib/v/checker/tests/option_fn_err.vv:40:9: error: assert can be used only with `bool` expressions, but found `bool` instead
    38 | 
    39 |     // assert
@@ -12,6 +26,20 @@ vlib/v/checker/tests/option_fn_err.vv:45:3: error: cannot assign an Option value
       |         ~~~~~~~~~~~~~
    46 |         opt: bar(0)
    47 |     }
+vlib/v/checker/tests/option_fn_err.vv:48:8: error: cannot use `?int` as `int`, it must be unwrapped first in argument 1 to `Data.add`
+   46 |         opt: bar(0)
+   47 |     }
+   48 |     v.add(bar(0)) // call method
+      |           ~~~~~~
+   49 |     v.f(bar(0)) // call fn field
+   50 |
+vlib/v/checker/tests/option_fn_err.vv:49:6: error: cannot use `?int` as `int`, it must be unwrapped first in argument 1 to `Data.f`
+   47 |     }
+   48 |     v.add(bar(0)) // call method
+   49 |     v.f(bar(0)) // call fn field
+      |         ~~~~~~
+   50 | 
+   51 |     // array
 vlib/v/checker/tests/option_fn_err.vv:56:27: error: cannot use unwrapped Option as initializer
    54 |     // init
    55 |     _ := [bar(0)]
@@ -26,6 +54,34 @@ vlib/v/checker/tests/option_fn_err.vv:60:13: error: cannot use Option or Result
       |                ~~~~~~~~
    61 |     // array builtin methods
    62 |     arr.insert(0, bar(0))
+vlib/v/checker/tests/option_fn_err.vv:62:16: error: cannot use `?int` as `voidptr`, it must be unwrapped first in argument 2 to `[]int.insert`
+   60 |     println(arr[bar(0)])
+   61 |     // array builtin methods
+   62 |     arr.insert(0, bar(0))
+      |                   ~~~~~~
+   63 |     arr.prepend(bar(0))
+   64 |     arr.contains(bar(0))
+vlib/v/checker/tests/option_fn_err.vv:63:14: error: cannot use `?int` as `voidptr`, it must be unwrapped first in argument 1 to `[]int.prepend`
+   61 |     // array builtin methods
+   62 |     arr.insert(0, bar(0))
+   63 |     arr.prepend(bar(0))
+      |                 ~~~~~~
+   64 |     arr.contains(bar(0))
+   65 |     arr.index(bar(0))
+vlib/v/checker/tests/option_fn_err.vv:64:15: error: cannot use `?int` as `int`, it must be unwrapped first in argument 1 to `.contains()`
+   62 |     arr.insert(0, bar(0))
+   63 |     arr.prepend(bar(0))
+   64 |     arr.contains(bar(0))
+      |                  ~~~~~~
+   65 |     arr.index(bar(0))
+   66 |     println(arr.map(bar(0)))
+vlib/v/checker/tests/option_fn_err.vv:65:12: error: cannot use `?int` as `int`, it must be unwrapped first in argument 1 to `.index()`
+   63 |     arr.prepend(bar(0))
+   64 |     arr.contains(bar(0))
+   65 |     arr.index(bar(0))
+      |               ~~~~~~
+   66 |     println(arr.map(bar(0)))
+   67 |     println(arr.filter(bar(true)))
 vlib/v/checker/tests/option_fn_err.vv:67:21: error: type mismatch, `bar` must return a bool
    65 |     arr.index(bar(0))
    66 |     println(arr.map(bar(0)))

vlib/v/checker/tests/option_ptr_without_unwrapp_err.out

@@ -0,0 +1,7 @@
+vlib/v/checker/tests/option_ptr_without_unwrapp_err.vv:7:13: error: cannot use `?&Node` as `Node`, it must be unwrapped first in argument 1 to `set_trace`
+    5 | fn set_trace(n Node) {
+    6 |     if n.parent != none {
+    7 |         set_trace(n.parent)
+      |                   ~~~~~~~~
+    8 |     }
+    9 | }

vlib/v/checker/tests/option_ptr_without_unwrapp_err.vv

@@ -0,0 +1,17 @@
+struct Node {
+	parent ?&Node
+}
+
+fn set_trace(n Node) {
+	if n.parent != none {
+		set_trace(n.parent)
+	}
+}
+
+fn main() {
+	mut initial_node := Node{
+		parent: none
+	}
+	set_trace(initial_node)
+	assert true
+}

vlib/v/gen/c/struct.v

@@ -549,7 +549,8 @@ fn (mut g Gen) struct_init_field(sfield ast.StructInitField, language ast.Langua
 		} else {
 			if sfield.typ != ast.voidptr_type && sfield.typ != ast.nil_type
 				&& (sfield.expected_type.is_ptr() && !sfield.expected_type.has_flag(.shared_f))
-				&& !(sfield.typ.is_ptr() || sfield.typ.is_pointer()) && !sfield.typ.is_number() {
+				&& !sfield.expected_type.has_flag(.option) && !(sfield.typ.is_ptr()
+				|| sfield.typ.is_pointer()) && !sfield.typ.is_number() {
 				g.write('/* autoref */&')
 			}
 

vlib/v/tests/option_unwrap_test.v

@@ -0,0 +1,27 @@
+struct Node {
+pub mut:
+	parent ?&Node
+	id     int
+}
+
+fn set_trace(n &Node) int {
+	if n.parent != none {
+		set_trace(n.parent or { &Node{} })
+		assert n.id != 0
+	} else {
+		assert n.id == 1
+	}
+	return n.id
+}
+
+fn test_main() {
+	mut initial_node := &Node{
+		parent: none
+		id: 1
+	}
+	mut child_node := &Node{
+		parent: initial_node
+		id: 2
+	}
+	assert set_trace(child_node) == 2
+}