fmt, ast: fix usage of import aliases (#10151)

vlib/v/ast/types.v

@@ -909,7 +909,7 @@ pub fn (t &Table) type_to_str_using_aliases(typ Type, import_aliases map[string]
 			} else {
 				if res.starts_with('fn (') {
 					// fn foo ()
-					res = t.fn_signature(info.func, type_only: true)
+					res = t.fn_signature_using_aliases(info.func, import_aliases, type_only: true)
 				} else {
 					// FnFoo
 					res = t.shorten_user_defined_typenames(res, import_aliases)
@@ -1001,9 +1001,14 @@ fn (t Table) shorten_user_defined_typenames(originalname string, import_aliases
 		mut parts := res.split('.')
 		if parts.len > 1 {
 			ind := parts.len - 2
+			if t.is_fmt {
+				// Rejoin the module parts for correct usage of aliases
+				parts[ind] = parts[..ind + 1].join('.')
+			}
 			if parts[ind] in import_aliases {
 				parts[ind] = import_aliases[parts[ind]]
 			}
+
 			res = parts[ind..].join('.')
 		} else {
 			res = parts[0]
@@ -1018,6 +1023,10 @@ pub struct FnSignatureOpts {
 }
 
 pub fn (t &Table) fn_signature(func &Fn, opts FnSignatureOpts) string {
+	return t.fn_signature_using_aliases(func, map[string]string{}, opts)
+}
+
+pub fn (t &Table) fn_signature_using_aliases(func &Fn, import_aliases map[string]string, opts FnSignatureOpts) string {
 	mut sb := strings.new_builder(20)
 	if !opts.skip_receiver {
 		sb.write_string('fn ')
@@ -1041,7 +1050,7 @@ pub fn (t &Table) fn_signature(func &Fn, opts FnSignatureOpts) string {
 		if !opts.type_only {
 			sb.write_string('$param.name ')
 		}
-		styp := t.type_to_str(typ)
+		styp := t.type_to_str_using_aliases(typ, import_aliases)
 		if i == func.params.len - 1 && func.is_variadic {
 			sb.write_string('...$styp')
 		} else {
@@ -1050,7 +1059,7 @@ pub fn (t &Table) fn_signature(func &Fn, opts FnSignatureOpts) string {
 	}
 	sb.write_string(')')
 	if func.return_type != ast.void_type {
-		sb.write_string(' ${t.type_to_str(func.return_type)}')
+		sb.write_string(' ${t.type_to_str_using_aliases(func.return_type, import_aliases)}')
 	}
 	return sb.str()
 }

vlib/v/fmt/fmt.v

@@ -75,11 +75,10 @@ pub fn fmt(file ast.File, table &ast.Table, pref &pref.Preferences, is_debug boo
 
 pub fn (mut f Fmt) process_file_imports(file &ast.File) {
 	for imp in file.imports {
-		mod := imp.mod.all_after_last('.')
-		f.mod2alias[mod] = imp.alias
+		f.mod2alias[imp.mod] = imp.alias
 		for sym in imp.syms {
 			f.mod2alias['${imp.mod}.$sym.name'] = sym.name
-			f.mod2alias['${mod}.$sym.name'] = sym.name
+			f.mod2alias['${imp.mod.all_after_last('.')}.$sym.name'] = sym.name
 			f.mod2alias[sym.name] = sym.name
 			f.import_syms_used[sym.name] = false
 		}
@@ -211,7 +210,8 @@ pub fn (mut f Fmt) short_module(name string) string {
 	if vals.len < 2 {
 		return name
 	}
-	mname, tprefix := f.get_modname_prefix(vals[vals.len - 2])
+	idx := vals.len - 1
+	mname, tprefix := f.get_modname_prefix(vals[..idx].join('.'))
 	symname := vals[vals.len - 1]
 	aname := f.mod2alias[mname]
 	if aname == '' {
@@ -2194,7 +2194,8 @@ pub fn (mut f Fmt) match_expr(node ast.MatchExpr) {
 }
 
 pub fn (mut f Fmt) offset_of(node ast.OffsetOf) {
-	f.write('__offsetof(${f.table.type_to_str(node.struct_type)}, $node.field)')
+	f.write('__offsetof(${f.table.type_to_str_using_aliases(node.struct_type, f.mod2alias)}, $node.field)')
+	f.mark_types_import_as_used(node.struct_type)
 }
 
 pub fn (mut f Fmt) or_expr(node ast.OrExpr) {
@@ -2427,7 +2428,7 @@ pub fn (mut f Fmt) string_inter_literal(node ast.StringInterLiteral) {
 }
 
 pub fn (mut f Fmt) type_expr(node ast.TypeNode) {
-	f.write(f.table.type_to_str(node.typ))
+	f.write(f.table.type_to_str_using_aliases(node.typ, f.mod2alias))
 }
 
 pub fn (mut f Fmt) type_of(node ast.TypeOf) {

vlib/v/fmt/tests/import_selective_input.vv

@@ -59,4 +59,3 @@ fn main() {
 	println(file_ext('main.v'))
 	println(imaginary(1))
 }
-

vlib/v/fmt/tests/import_selective_keep.vv

@@ -0,0 +1,5 @@
+import math.complex { Complex }
+
+fn main() {
+	assert *(&f64(&byte(&num) + __offsetof(Complex, re))) == 1.0
+}

vlib/v/fmt/tests/import_with_alias_keep.vv

@@ -1,6 +1,8 @@
 import os
 import time as t
 import some.library as slib
+import crypto.sha256
+import mymod.sha256 as mysha256
 
 type my_alias = fn (t slib.MyType)
 
@@ -18,4 +20,6 @@ fn main() {
 	t.sleep_ms(500)
 	println('end')
 	os.system('date')
+	v_hash := sha256.sum('hi'.bytes()).hex()
+	my_hash := mysha256.sum('hi'.bytes()).hex()
 }

vlib/v/fmt/tests/module_alias_keep.vv

@@ -1,6 +1,7 @@
 import time
 import semver as sv
 import term.ui as tui
+import v.ast
 
 interface Inter {
 	code tui.KeyCode
@@ -24,3 +25,12 @@ fn bar_multi_return(b sv.Version) (sv.Version, int) {
 	b2 := sv.Version{}
 	return b, 0
 }
+
+struct SomeStruct {
+	a fn (ast.Stmt, voidptr) bool
+}
+
+fn main() {
+	if x is ast.FnDecl {
+	}
+}