checker: fix static methods not recognized when imported from a module(…

…fix #19127)

vlib/v/checker/fn.v

@@ -841,6 +841,23 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 			c.table.fns[fn_name].usages++
 		}
 	}
+	// already imported symbol (static Foo.new() in another module)
+	if !found && fn_name[0].is_capital() && fn_name.contains('__static__') {
+		if index := fn_name.index('__static__') {
+			owner_name := fn_name#[..index]
+			for import_sym in c.file.imports.filter(it.syms.len > 0
+				&& it.syms.any(it.name == owner_name)) {
+				qualified_name := '${import_sym.mod}.${fn_name}'
+				if f := c.table.find_fn(qualified_name) {
+					found = true
+					func = f
+					node.name = qualified_name
+					c.table.fns[qualified_name].usages++
+					break
+				}
+			}
+		}
+	}
 	mut is_native_builtin := false
 	if !found && c.pref.backend == .native {
 		if fn_name in ast.native_builtins {
@@ -936,7 +953,11 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 	// a same module constant?
 	if !found {
 		// allow for `const abc = myfunc`, then calling `abc()`
-		qualified_const_name := if fn_name.contains('.') { fn_name } else { '${c.mod}.${fn_name}' }
+		mut qualified_const_name := if fn_name.contains('.') {
+			fn_name
+		} else {
+			'${c.mod}.${fn_name}'
+		}
 		if mut obj := c.table.global_scope.find_const(qualified_const_name) {
 			if obj.typ == 0 {
 				obj.typ = c.expr(mut obj.expr)

vlib/v/checker/tests/modules/import_static_fn.out

@@ -0,0 +1 @@
+amod.SomeStruct{}

vlib/v/checker/tests/modules/import_static_fn/src/amod/amod.v

@@ -0,0 +1,7 @@
+module amod
+
+pub struct SomeStruct {}
+
+pub fn SomeStruct.new() SomeStruct {
+	return SomeStruct{}
+}

vlib/v/checker/tests/modules/import_static_fn/src/main.v

@@ -0,0 +1,10 @@
+module main
+
+import amod { SomeStruct }
+
+fn main() {
+	_ = SomeStruct{}
+
+	result := SomeStruct.new()
+	println(result)
+}