checker: fix assign check, when rechecking for another concrete type (#23212)

Author: felipensp

vlib/v/checker/assign.v

@@ -182,6 +182,17 @@ fn (mut c Checker) assign_stmt(mut node ast.AssignStmt) {
 				node.right_types << c.check_expr_option_or_result_call(node.right[i],
 					right_type)
 			}
+		} else {
+			// on generic recheck phase it might be needed to resolve the rhs again
+			if i < node.right.len && c.comptime.has_comptime_expr(node.right[i]) {
+				mut expr := mut node.right[i]
+				old_inside_recheck := c.inside_recheck
+				c.inside_recheck = true
+				right_type := c.expr(mut expr)
+				node.right_types[i] = c.check_expr_option_or_result_call(node.right[i],
+					right_type)
+				c.inside_recheck = old_inside_recheck
+			}
 		}
 		mut right := if i < node.right.len { node.right[i] } else { node.right[0] }
 		mut right_type := node.right_types[i]
@@ -494,7 +505,6 @@ fn (mut c Checker) assign_stmt(mut node ast.AssignStmt) {
 					if (left.is_map || left.is_farray) && left.is_setter {
 						left.recursive_mapset_is_setter(true)
 					}
-
 					right_type = c.comptime.get_type_or_default(right, right_type)
 				}
 				if mut left is ast.InfixExpr {

vlib/v/checker/checker.v

@@ -77,6 +77,7 @@ pub mut:
 	is_builtin_mod              bool // true inside the 'builtin', 'os' or 'strconv' modules; TODO: remove the need for special casing this
 	is_just_builtin_mod         bool // true only inside 'builtin'
 	is_generated                bool // true for `@[generated] module xyz` .v files
+	inside_recheck              bool // true when rechecking rhs assign statement
 	inside_unsafe               bool // true inside `unsafe {}` blocks
 	inside_const                bool // true inside `const ( ... )` blocks
 	inside_anon_fn              bool // true inside `fn() { ... }()`
@@ -1774,7 +1775,7 @@ fn (mut c Checker) selector_expr(mut node ast.SelectorExpr) ast.Type {
 	}
 
 	if has_field {
-		is_used_outside := sym.mod != c.mod
+		is_used_outside := !c.inside_recheck && sym.mod != c.mod
 		if is_used_outside && !field.is_pub && sym.language != .c {
 			unwrapped_sym := c.table.sym(c.unwrap_generic(typ))
 			c.error('field `${unwrapped_sym.name}.${field_name}` is not public', node.pos)

vlib/v/comptime/comptimeinfo.v

@@ -36,6 +36,17 @@ pub fn (mut ct ComptimeInfo) is_comptime_expr(node ast.Expr) bool {
 		|| node is ast.ComptimeSelector
 }
 
+// has_comptime_expr checks if the expr contains some comptime expr
+@[inline]
+pub fn (mut ct ComptimeInfo) has_comptime_expr(node ast.Expr) bool {
+	return (node is ast.Ident && node.ct_expr)
+		|| (node is ast.IndexExpr && ct.has_comptime_expr(node.left))
+		|| node is ast.ComptimeSelector
+		|| (node is ast.SelectorExpr && ct.has_comptime_expr(node.expr))
+		|| (node is ast.InfixExpr && (ct.has_comptime_expr(node.left)
+		|| ct.has_comptime_expr(node.right)))
+}
+
 // is_comptime checks if the node is related to a comptime marked variable
 @[inline]
 pub fn (mut ct ComptimeInfo) is_comptime(node ast.Expr) bool {
@@ -100,6 +111,7 @@ pub fn (mut ct ComptimeInfo) get_expr_type_or_default(node ast.Expr, default_typ
 }
 
 // get_type_or_default retries the comptime value if the AST node is related to comptime otherwise default_typ is returned
+@[inline]
 pub fn (mut ct ComptimeInfo) get_type_or_default(node ast.Expr, default_typ ast.Type) ast.Type {
 	match node {
 		ast.Ident {

vlib/v/tests/generics/generic_selector_indexexpr_test.v

@@ -0,0 +1,44 @@
+module main
+
+pub struct Vector[T] {
+	n      int
+	values []T
+}
+
+pub fn Vector.new[T](v []T) Vector[T] {
+	return Vector[T]{
+		n:      v.len
+		values: v
+	}
+}
+
+pub fn (v Vector[T]) str() string {
+	return v.values.str()
+}
+
+pub fn (v Vector[T]) + (u Vector[T]) Vector[T] {
+	assert v.n == u.n
+	return Vector[T]{
+		n:      v.n
+		values: []T{len: v.n, init: T(v.values[index] + u.values[index])}
+	}
+}
+
+pub fn (v Vector[T]) dot(u Vector[T]) T {
+	assert v.n == u.n
+	mut sum := T(0)
+	for i in 0 .. v.n {
+		sum += v.values[i] * u.values[i]
+	}
+	return sum
+}
+
+fn test_main() {
+	v := Vector.new[f64]([1.0, 2, 3])
+	vdotv := v.dot(v)
+	assert vdotv == 14.0
+
+	u := Vector.new[int]([1, 2, 3])
+	udotu := u.dot(u)
+	assert udotu == 14
+}

vlib/x/json2/decoder2/decode_sumtype.v

@@ -8,9 +8,15 @@ fn (mut decoder Decoder) get_decoded_sumtype_workaround[T](initialized_sumtype T
 			if initialized_sumtype is v {
 				// workaround for auto generated function considering sumtype as array
 				unsafe {
-					mut val := initialized_sumtype
-					decoder.decode_value(mut val)!
-					return T(val)
+					$if initialized_sumtype is $map {
+						mut val := initialized_sumtype.clone()
+						decoder.decode_value(mut val)!
+						return T(val)
+					} $else {
+						mut val := initialized_sumtype
+						decoder.decode_value(mut val)!
+						return T(val)
+					}
 				}
 			}
 		}